Understanding Electrical Conduction and Nanopore Formation During Controlled Breakdown

Controlled breakdown has recently emerged as a highly appealing technique to fabricate solid-state nanopores for a wide range of biosensing applications. This technique relies on applying an electric field of approximately 0.4-1 V nm^-1 across the membrane to induce a current, and eventually, breakdown of the dielectric. Although previous studies have performed controlled breakdown under a range of different conditions, the mechanism of conduction and breakdown has not been fully explored. Here, electrical conduction and nanopore formation in SiN_x membranes during controlled breakdown is studied. It is demonstrated that for Si-rich SiN_x , oxidation reactions that occur at the membrane-electrolyte interface limit conduction across the dielectric. However, for stoichiometric Si₃ N₄ the effect of oxidation reactions becomes relatively small and conduction is predominately limited by charge transport across the dielectric. Several important implications resulting from understanding this process are provided which will aid in further developing controlled breakdown in the coming years, particularly for extending this technique to integrate nanopores with on-chip nanostructures.

THORACIC ORIGIN OF THE RIGHT RENAL ARTERY: AN INCIDENTAL FINDING

Thoracic origin of a single renal artery with a normal position of the kidney is a very rare anatomical variant with just a dozen cases depicted in the medical literature. In this case report we describe an incidental finding of a main renal artery arising from the thoracic aorta at the 11th thoracic vertebral level in an asymptomatic 57 year-old man in a routine computed tomography (CT) on follow-up for chronic pancreatitis.

Saharan dust intrusions in the Iberian Peninsula: Predominant synoptic conditions

The Iberian Peninsula (IP) is recurrently affected by dust transport from the Sahara Desert and from the semi-arid Sahel regions. African dust is one of the most important sources of particulate matter in the southern Mediterranean. Therefore, it is vital to understand the underlying processes that lead to episodes of air pollution associated to the occurrence of dust intrusions. This work proposes to make an extended characterization of the preferential circulation weather patterns associated to the onset of dust events affecting the IP between 2006 and 2016. Saharan dust intrusions were analysed and an automatic objective classification procedure was used to classify circulation weather patterns associated to dust events. The spatial distribution of intrusion episodes is not homogeneous throughout the IP, occurring less frequently at northern and northwestern locations than at central and southern sites. Moreover, days with Saharan dust intrusions were more frequent in summer months, and more probable to occur under regimes with a southerly component. Finally, two extreme events with high concentration of particulate matter were analysed relatively to their life-cycle and particle trajectories. The distinct extreme episodes can be associated to different synoptic situations. However, and despite different large-scale configurations, a south or south-easterly component over the region is responsible for the establishment of a dust transport from the Saharan region towards Iberia, and thus leading to the intrusion onset. These results were supported by the calculation of back-trajectories which allowed to source apportioning the particles' origin, through a clear trajectory of air parcels originating from northern Africa in both events. The proposed framework can be useful to the prediction of dust and air pollution events based on the forecast of circulation weather patterns, as the results show that these events across the IP are mainly induced by specific patterns.

[Smoking Cessation after Bladder Cancer Diagnosis]

INTRODUCTION

Smoking is an important risk factor for the development, recurrence and progression of bladder cancer. Our aim was to analyze smoking habits after diagnosis in bladder cancer patients. Additionally, we evaluated patient knowledge about smoking as a risk factor and the urologist role in promoting abstinence.

MATERIAL AND METHODS

A cross-sectional, observational and descriptive study was performed in bladder cancer patients, diagnosed between January 2013 and September 2015 (n = 160) in Braga Hospital, in Portugal.

RESULTS

Smoking history was present in 71.9% of the sample, with 21.9% current smokers, (40.7% of abstinence after diagnosis). Smoking was acknowledged as a risk factor by 74.4% of the sample, with only 51.3% of ever smokers and 24.4% of non-smokers recognizing smoking as the leading risk factor (p = 0.008). The presence of other household smokers were significantly higher in patients who continued smoking (40%) than in ex-smokers after diagnosis (4.2%) (p = 0.005). The majority of smokers at diagnosis (83.1%) were advised to quit by their urologist, but only one smoker (1.7%) was offered any specific intervention to aid in cessation.

DISCUSSION

Smoking is not recognized as the leading risk factor for bladder cancer. This limited awareness, associated with the known difficulties in quitting smoking and the observed lack of smoking cessation interventions, may account for the high current smoking prevalence, albeit in line with other studies.

CONCLUSION

This study highlights the need for efficient smoking cessation programs directed to bladder cancer patients.

[Relationships between widespread pain and thresholds pain tolerance on tender points in Portuguese women with fibromyalgia: impact on daily life]

OBJECTIVES

to establish a relationship between widespread pain subjectively perceived and threshold pain tolerance on tender points, and to determine whether there are differences in threshold pain tolerance on tender points between the upper and lower body, as well as between the dominant and non-dominant side, and whether these differences have an impact on the daily life of Portuguese women with fibromyalgia (FM).

MATERIAL & METHODS

thirty-one women with FM aged between 34 and 67 years volunteered for the study. Threshold pain tolerance was assessed at critical points using a digital algometer pressure; the widespread pain index (WPI) was constructed by the addition of 19 painful body regions; and the impact on the daily life assessed by the Portuguese version of the Fibromyalgia Impact Questionnaire (FIQ), with individual interviews.

RESULTS

significant differences between the percentage of threshold pain tolerance of the whole body and the scales of widespread pain subjectively perceived were observed, showing that the widespread pain subjectively perceived by patients was between +25.9% and +27.5%. Also, significant differences between threshold pain tolerance of tender points located on the upper and lower body (1.9 ± 0.5 kg/cm2 vs. 2.6 ± 0.7 kg/cm2; respectively) were observed. However, no significant differences were found between threshold pain tolerance of tender points located on dominant and non-dominant sides (2.1 ± 0.5 kg/cm2 e 2.1 ± 0.6 kg/cm2; respectively). Additionally, the analysis showed significant correlations between pain and patient`s daily life in: FIQ total score, physical function, feel good, job ability and fatigue.

CONCLUSIONS

the women with FM show higher widespread pain subjectively perceived than threshold pain tolerance on tender points. Furthermore, the pain suffered by the patients with FM, especially that located on the upper body, either on the dominant or on the non-dominant side, has a negative influence on physical function, job ability, fatigue and feel good, affecting daily life.

Coexistence of universal and topological anomalous hall effects in metal CrO2 thin films in the dirty limit

The scaling exponent of 1.6 between anomalous Hall and longitudinal conductivity, characteristic of the universal Hall mechanism in dirty-metal ferromagnets, emerges from a series of CrO2 films as we systematically increase structural disorder. Magnetic disorder in CrO2 increases with temperature and this drives a separate topological Hall mechanism. We find that these terms are controlled discretely by structural and magnetic defect populations, and their coexistence leads to apparent divergence from exponent 1.6, suggesting that the universal term is more prevalent than previously realized.