Human Factors Issues and the Risk of High Voltage Equipment: Are Standards Sufficient to Ensure Safety by Design?

High voltage equipment is mostly designed according to technically prescriptive standards requirements based on electrical engineering safety principles. However a more risk-based approach to standards and regulation may be advisable to enable designer and user to take an active role in establishing that their installation is inherently safe. The use of Gas Insulated Switchgear (GIS) for instance is enabling the new substation to be housed indoors and condensed into around one quarter of the space. The manufacturers argue that design improvements in GIS make it virtually “maintenance free”, comply with all the relevant standards. However some of these improvements have implications for the operators that need to be taken into account. Commissioning, operational checks and inspections and the occasional maintenance interventions are activities during which the technicians need to interface with the equipment, the issues regarding the interfaces provided have been analysed to identify their relevance in the overall risk assessment of the equipment. The paper reports about a study aimed at verifying through a risk analysis the impacts that the issues related to deficit in ergonomic design may present for the overall availability and safety of the plant. Those issues are not tackled in the technical standards and/or designers current practice

Evaluation of the root filling quality with experimental carrier-based obturators: a CLSM and FEG-SEM analysis

This study evaluated tubule penetration of GuttaFlow Bioseal with cold single cone or carrier-based technique, under confocal laser scanning microscopy (CLSM). Twenty straight single-rooted teeth were instrumented with Hyflex CM and divided in two groups (n = 10) according to the obturation method: single cold gutta-percha cones; experimental carrier-based obturators. GuttaFlow Bioseal, labelled with Rhodamine B dye, was used as sealer in both groups. Teeth transversally sectioned were observed under CLSM. Percentage of sealer penetration and integrity of sealer layer perimeter were measured. Surface and microstructural characteristics of obturators and gutta-percha cones were compared by FEG-SEM and EDX analysis. No significant differences were found between groups for each examined parameter. Significant differences (P < 0.05) were reported mainly within groups. Integrity was similar among and within groups. FEG-SEM/EDX analysis of obturators revealed the presence of Ba and Zn. Carrier-based obturation technique associated with GuttaFlow Bioseal does not seem to affect sealer penetration into dentinal tubules

Cyclic fatigue resistance of Nickel-Titanium reciprocating instruments tested with an innovative kinematics

Aim: To evaluate cyclic fatigue resistance of different Nickel-Titanium instruments tested with an innovative reciprocating kinematics. Methodology: Eighty Nickel-Titanium reciprocating instruments were tested in cyclic fatigue resistance: WaveOne Primary (n = 20), WaveOne Gold Primary (n = 20), Reciproc R25 (n = 20) and Reciproc Blue R25 (n = 20). The cyclic fatigue of each brand was measured with two different motors and kinematics settings: (1) X-Smart Plus (Denstply Maillefer) used in \u2018\u2018WaveOne All\u2019\u2019 or \u2018\u2018Reciproc All\u2019\u2019 setting, according to manufacturer\u2019s instruction; (2) a 4:1 contra-angle (Cefla, Imola, Italy) with an experimental kinematics (Goldspeed EVOE4 \u2014 Cefla, Italy) (EVO) with different rotation angles and based on a sinusoidal acceleration. The time to fracture in an artificial stainless-steel canal (908 angle and a 5-mm radius of curvature) was digitally recorded. Mean life, beta (failure rate) and eta (characteristic life i.e. the number of seconds at which 63.2% of the product has failed) were calculated for each group and compared with Weibull analysis. Results: InstrumentstestedwiththekinematicsEVOpresentedhighervaluesofetainallgroups. Reciproc Blue showed the highest eta value (233.05) and Wave One Gold the lower failure probability (46.98%). Wave One instruments showed similar fatigue resistance when tested with EVO or X-Smart. Conclusion: Tested kinematics with different angles and based on sinusoidal reciprocating acceleration had a positive impact on fatigue lifetime of reciprocating instruments. Present findings suggest the possibility of future improvements in the clinical use of reciprocating files

Cost-effectiveness of intravitreal therapy in Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is still referred to as the leading cause of severe and irreversible visual loss world-wide. Advances in medical research have identified vascular endothelial growth factor (VEGF) as an important pathophysiological player in neovascular AMD and intraocular inhibition of VEGF as one of the most efficient therapies. Anti-VEGFs currently used to treat AMD included a monoclonal antibody (bevacizumab), an antibody fragments (ranibizumab), a fusion protein (aflibercept), and an aptamer (pegaptanib). The wide introduction of anti-VEGF therapy has led to an improvement in the prognosis of patients affected by AMD, with a consequent effects on the burden of care due to highly priced drugs, increasing patient numbers, and long-term disease chronicity. Aim of this review is to present an overview of available therapeutic strategies in AMD in term of clinical efficacy and economic sustainability

Reliability of forced internal rotation and active internal rotation to assess lateral instability of the biceps pulley

Purpose: the aim of this study was to investigate the relationship between positive painful forced internal rotation (FIR) and lateral pulley instability in the presence of a pre-diagnosed posterosuperior cuff tear. The same investigation was conducted for painful active internal rotation (AIR). Methods: a multicenter prospective study was conducted in a series of patients scheduled to undergo arthroscopic posterosuperior cuff repair. Pain was assessed using a visual analog scale (VAS) and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH) was administered. The VAS score at rest, DASH score, and presence/absence of pain on FIR and AIR were recorded and their relationships with lesions of the lateral pulley, cuff tear patterns and shape of lesions were analyzed. Results: the study population consisted of 115 patients (mean age: 55.1 years) recruited from 12 centers. The dominant arm was affected in 72 cases (62.6%). The average anteroposterior extension of the lesion was 1.61 cm. The mean preoperative VAS and DASH scores were 6.1 and 41.8, respectively. FIR and AIR were positive in 94 (81.7%) and 85 (73.9%) cases, respectively. The lateral pulley was compromised in 50 cases (43.4%). Cuff tears were partial articular in 35 patients (30.4%), complete in 61 (53%), and partial bursal in 19 (16.5%). No statistical correlation between positive FIR or AIR and lateral pulley lesions was detected. Positive FIR and AIR were statistically associated with complete lesions. Negative FIR was associated with the presence of partial articular tears. Conclusions: painful FIR in the presence of a postero-superior cuff tear does not indicate lateral pulley instability. When a cuff tear is suspected, positive FIR and AIR are suggestive of full-thickness tear patterns while a negative FIR suggests a partial articular lesion. Level of evidence: level I, validating cohort study with good reference standards

Income level and chronic ambulatory care sensitive conditions in adults: a multicity population-based study in Italy

<p>Abstract</p> <p>Background</p> <p>A relationship between quality of primary health care and preventable hospitalizations has been described in the US, especially among the elderly. In Europe, there has been a recent increase in the evaluation of Ambulatory Care Sensitive Conditions (ACSC) as an indicator of health care quality, but evidence is still limited. The aim of this study was to determine whether income level is associated with higher hospitalization rates for ACSC in adults in a country with universal health care coverage.</p> <p>Methods</p> <p>From the hospital registries in four Italian cities (Turin, Milan, Bologna, Rome), we identified 9384 hospital admissions for six chronic conditions (diabetes, hypertension, congestive heart failure, angina pectoris, chronic obstructive pulmonary disease, and asthma) among 20-64 year-olds in 2000. Case definition was based on the ICD-9-CM coding algorithm suggested by the Agency for Health Research and Quality - <it>Prevention Quality Indicators</it>. An area-based (census block) income index was used for each individual. All hospitalization rates were directly standardised for gender and age using the Italian population. Poisson regression analysis was performed to assess the relationship between income level (quintiles) and hospitalization rates (RR, 95% CI) separately for the selected conditions controlling for age, gender and city of residence.</p> <p>Results</p> <p>Overall, the ACSC age-standardized rate was 26.1 per 10.000 inhabitants. All conditions showed a statistically significant socioeconomic gradient, with low income people being more likely to be hospitalized than their well off counterparts. The association was particularly strong for chronic obstructive pulmonary disease (level V low income vs. level I high income RR = 4.23 95%CI 3.37-5.31) and for congestive heart failure (RR = 3.78, 95% CI = 3.09-4.62). With the exception of asthma, males were more vulnerable to ACSC hospitalizations than females. The risks were higher among 45-64 year olds than in younger people.</p> <p>Conclusions</p> <p>The socioeconomic gradient in ACSC hospitalization rates confirms the gap in health status between social groups in our country. Insufficient or ineffective primary care is suggested as a plausible additional factor aggravating inequality. This finding highlights the need for improving outpatient care programmes to reduce the excess of unnecessary hospitalizations among poor people.</p