Semi-transparent 3D microelectrodes buried in fused silica for photonics applications.

We report the realization of semi-transparent 3D microelectrodes fully embedded in a fused silica substrate by a combination of femtosecond laser microfabrication and inkjet printing. We also demonstrate the application of such electrodes in a proof-of-concept lab-on-chip device configuration, which acts as a liquid crystal molecular polarization rotator using on-chip electric fields. This work constitutes a first of its kind synergy between two widely used microfabrication techniques, femtosecond laser and inkjet, demonstrating a very efficient integration of optical, electrical and microfluidic components in a unique platform and thus enabling fast prototyping of 3D structured electro-optic lab-on-chips.

Thermoelectric characterization of flexible micro-thermoelectric generators.

A new experimental setup for the characterization of flexible micro-thermoelectric generators is reported. The system can measure the power generated and the thermoelectric conversion efficiency of devices under mechanical stresses and deformations, in atmospheric environment and under vacuum, in the temperature interval 293 K-423 K, as a function of the load resistance and of the mechanical pressure, with an uncertainty on the temperature difference of ±0.02 K. The system has been tested on commercial rigid devices and on a custom-made, flexible, proof-of-concept, organic-inorganic hybrid generator made of eight thermocouples. Repeatability on the power generated and conversion efficiency within 5% and 3%, respectively, was demonstrated, and accuracy of the measurement was granted by minimization of all the potential sources of heat flux losses.

Reliable measurement of the Seebeck coefficient of organic and inorganic materials between 260 K and 460 K.

A new experimental setup for reliable measurement of the in-plane Seebeck coefficient of organic and inorganic thin films and bulk materials is reported. The system is based on the "Quasi-Static" approach and can measure the thermopower in the range of temperature between 260 K and 460 K. The system has been tested on a pure nickel bulk sample and on a thin film of commercially available PEDOT: PSS deposited by spin coating on glass. Repeatability within 1.5% for the nickel sample is demonstrated, while accuracy in the measurement of both organic and inorganic samples is guaranteed by time interpolation of data and by operating with a temperature difference over the sample of less than 1 K.

The critical role of interfacial dynamics in the stability of organic photovoltaic devices.

Understanding the stability and degradation mechanisms of organic solar materials is required to achieve long device lifetimes. Here we study photodegradation mechanisms of the (poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)]):[6,6]-phenyl-C61-butyric acid methyl ester (PCPDTBT:PCBM) low band gap-based photovoltaic blend. We apply quasi steady state Photo-induced Absorption Optical Spectroscopy, time-resolved Electron Spin Resonance Spectroscopy and theoretical modeling to investigate the dynamics of long-lived photoexcited species. The role of the interfacial physics in the efficiency and robustness of the photovoltaic blend is clarified. We demonstrate that the polymer triplet state (T), populated through the interfacial charge transfer (CT) state recombination, coexists with charge carriers. However, in contrast to previous suggestions, it has no role in the degradation process caused by air exposure. Instead, the long-lived emissive interfacial CT state is responsible for the blend degradation in air. It mediates direct electron transfer to contaminants, leading to the formation of reactive and harmful species, such as the superoxide.

Fully inkjet-printed organic photodetectors with high quantum yield.

Bulk-heterojunction based organic photodetectors are fabricated by means of drop-on-demand inkjet printing with vertical topology, inverted structure, and small footprint (about 100 µm x 100 µm). Due to optimization of the deposition technique, an external quantum efficiency in excess of 80% at 525 nm and a -3dB bandwidth of a few tens of kHz is achieved.

Update of the mortality study of workers exposed to polychlorinated biphenyls (Pcbs) in two Italian capacitor manufacturing plants.

BACKGROUND: PCB carcinogenicity to humans is still controversial. Cohort mortality studies in PCB-exposed workers reported elevated risks for the following causes of death: liver, stomach, digestive, brain, prostate cancers and non-Hodgkin lymphoma. OBJECTIVES: The purpose of this study was to update as of December 2006 the mortality experience of two Italian cohorts of workers employed in the manufacture of capacitors impregnated with PCBs. METHODS: Age-gender-and calendar period adjusted Standardized Mortality Ratios (SMRs) and 95% Confidence Intervals (CI) were calculated using regional rates. Analyses by duration of employment and time since first employment were performed Results: Vital status was ascertained for 98.9% of the study subjects. Mortality from biliary tract cancer among males (SMR 3.91; 95%CI 1.47-10.41), digestive cancer "not otherwise specified" in the whole cohort (SMR 2.54; 95%CI 1.21-5.34), and brain cancer in Plant I (SMR 2.13; 95%CI 1.02-4.48), were significantly increased. Increased risks were also observed for Hodgkin's and non-Hodgkin lymphoma. No linear associations between mortality and duration of employment or latency were observed for these cancers. Mortality from stomach cancer did not differ from expectation in the whole cohort, however an increasing risk with increasing duration of employment was detected (p for trend=0.02). CONCLUSIONS: The current update suggests possibly increased cancer risks in PCB-exposed workers, affecting in particular the digestive system, brain, and lymphohemopoietic tissue. However the limited sample size, the lack of clear trends with duration of employment or with latency period, preclude to derive definite conclusions about PCB exposure and the increased cancer risks.

[Vigilance in application of law 125/2001 concerning alcohol and alcohol-related risk assessment in workplaces]. / Vigilanza sull'applicazione della legge 125/2001. Indicazioni per la gestione nei luoghi di lavoro dei rischi alcol correlati.

BACKGROUND AND OBJECTIVES: The prohibition of using, dispensing or distributing alcoholic drinks at workplaces involving an elevated risk of accidents (Art. 15 - Law 125/2001 "General policy concerning alcohol and alcohol- related problems") is consistent with the duties of employers and employees regulated by Decree 626/94. The purpose of this rule of law is the health protection of workers and of any third party in the workplace. Alcohol-addiction in workers has to be considered as part of the risk assessment and, in the case of the hazardous activities identified in the law, the increase in risk due to alcohol consumption must also be considered RESULTS AND CONCLUSIONS: Along with the prohibition of dispensing or distributing alcoholic drinks at the workplace, companies can launch training and information campaigns on the adverse health effects resulting from by harmful and hazardous alcohol consumption in workplaces, which will be all the more effective if addressed to all workers and not only to the more exposed employees. In developing this activity, the company occupational health physician has a central role to play by giving assistance to employees, involving the management and cooperating with public institutions. The controlling body will promote, support and supervise this process. In particular, the local authorities for Occupational Health and Safety (PSAL), together with social partners, will encourage companies to start up projects for health protection, will facilitate cooperation with the Pathological Addiction Services (Ser. T), and will encourage the implementation of a network to facilitate occupational health physicians in analyzing accident risks and solving health problems related to alcohol abuse.

[Introductional results of a mortality study in 471 ex-exposed workers to PCBs]. / Risultati preliminari di uno studio di mortalità in 471 lavoratori ex esposti a PCBs.

This study concerned a group of ex-workers (372 males and 99 females) from a firm situated in Bergamo (Italy) that ceased its activity at the beginning of the Nineties. From an introductory analysis of the results, we found out that there isn't excess in the death-rate for liver and bile ducts cancers among the males of this group. Among them, for what concerns the other tumoral pathologies, such as leukaemia and stomach tumors, the information allowed to verify an excess of mortality. However, this increase hasn't result statistically significant. On the contrary, it came out that there is an excess of risk for intestine tumors: standardized death-rate of 2.58. In accordance with the information collected, for the future it will be necessary to carefully examine the research in order to verify the existence of a direct connection to the exposure at PCB and study the incidence (not only for mortality) of these neoplasms.

Occupational exposure to metallic cobalt in the Province of Bergamo. Results of a 1991 survey.

The results of a survey on workers potentially exposed to cobalt in the Bergamo Province are reported. Its aim is to assess the number of workers at risk of developing respiratory disease due to the inhalation of metallic cobalt. Interest was shown after an examination of 11 cases of 'hard metal disease', which we diagnosed, in workers who came from different production areas and had different degrees of exposure. A first group of 45 factories with potential cobalt exposure was identified by consulting the archives of the Local Sanitary Units (USSL) and of the Chamber of Commerce, and by use of the telephone directory and requesting information from the producers and users of Widia tools. A second group of 2039 factories was selected from those industrial activities where we had previously ascertained the presence of grinding operations using hard metal tools with diamond wheels. This study is related to all the factories in the first group and 10% of the factories in the second group. More than 304 inspections were carried out. In this context 403 exposed workers were identified. Workplace air measurements (250 samples) and biological monitoring (> 600 samples) to determine the exposure levels to cobalt were performed. The results show an unexpected diffuse occupational exposure in different production areas where the airborne cobalt is frequently underestimated and higher than the TLV.

Health survey of workers occupationally exposed to cobalt.

The results are presented for a health control program using 236 male workers exposed to a cobalt inhalation risk. The study group consisted of grinders, producers of diamond tools, workers in metallurgical and mechanical industries (where Widia tools are processed and sharpened), and finally formerly exposed workers. All subjects received a clinical examination, the European Community for Coal and Steel questionnaire on respiratory complaints, a chest X-ray, pulmonary function test, electrocardiogram and determination of urinary cobalt; in 91 subjects, the metacholine bronchial provocation test was performed. Three cases of interstitial lung disease were identified. There were no cases with a significant alteration of ventilatory function while 20 cases (16 exposed and four formerly exposed workers) showed a reduced carbon monoxide transfer coefficient (TL,CO,sb/Va).

Cobalt exposure evaluation in dental prostheses production.

Dental laboratory technicians may be exposed to a number of toxic materials including metal alloys that have been identified as potential health hazards. Particularly, alloys, such as vitallium, wisil, duralium and vironite which in dentistry are used in the production of crowns, bridges and dental prostheses. The most common constituents of these prostheses are cobalt (45-70%), chromium (25-30%), molybdenum, silica, nickle, tantalum and other metals in different amounts. The objectives of this paper are to describe the technology related to the production of dental prostheses, evaluating the most hazardous working jobs and reporting results concerning the monitoring of cobalt and chromium in the urine of 31 people employed in five laboratories of Bergamo, Italy, where workplace air monitoring has also been undertaken.