Flow and fracture near the sol-gel transition of silica nanoparticle suspensions

Role of multidimensional factors in the diagnosis and treatment of tonsillopharyngitis in primary care: a qualitative study

Background

Tonsillopharyngitis is one of the most frequently observed upper respiratory tract infections, for which antibiotics are prescribed in ambulatory care. In most cases, tonsillopharyngitis is benign and self-limiting, mostly a viral condition. The aim of this study was to explore the diagnostic and treatment process of tonsillopharyngitis by general practitioners and to understand decisions regarding antibiotic prescribing and the factors that shape these practices.

Methods/design

This was a qualitative interview study in primary care practices in Latvia. Semi-structured face-to-face interviews were conducted with general practitioners from November 2016 to January 2017. Thematic analysis was applied to identify factors that influence the prescribing practice in a primary care setting in conjunction with a specific context in which the prescriber practices.

Results

Decisions and practice of general practitioner are not static over time or context; they occur within an environmental setting influenced by individual factors of general practitioners, the health care system, and practice-specific factors that shape the diagnosis and antibiotic prescribing in the tonsillopharyngitis. Interviewed general practitioners rely primarily on their personal experience, perception, and skills acquired in their practice, which are encouraged by the environment, where the necessary tools and resources are not in place to encourage rational prescribing of antibiotics.

Conclusions

General practitioners’ decision regarding antibiotic prescribing is an unstable concept that differs between prescribers. The health care system could augment the experience of general practitioners through structural changes such as guidelines, availability of antibiotics, and available antibiotics package size.

Unraveling driving regimes for destabilizing concentrated emulsions within microchannels

Coalescence is the most widely demonstrated mechanism for destabilizing emulsion droplets in microfluidic chambers. However, we find that depending on the channel wall surface functionalization, surface zeta potential, type of surfactant, characteristics of the oil as a dispersed phase, or even the presence of externally-induced stress, other different destabilization mechanisms can occur in subtle ways. In general, we observe four regimes leading to destabilization of concentrated emulsions: (i) coalescence, (ii) emulsion bursts, (iii) a combination of the two first mechanisms, attributed to the simultaneous occurrence of coalescence and emulsion bursts; and (iv) compaction of the droplet network that eventually destabilizes to fracture-like behavior. We correlate various physico-chemical properties (zeta potential, contact angle, interfacial tension) to understand their respective influence on the destabilization mechanisms. This work provides insights into possible ways to control or inflict emulsion droplet destabilization for different applications.

Microscopic precursors of failure in soft matter

The mechanical properties of soft matter are of great importance in countless applications, in addition of being an active field of academic research. Given the relative ease with which soft materials can be deformed, their non-linear behavior is of particular relevance. Large loads eventually result in material failure. In this Perspective article, we discuss recent work aiming at detecting precursors of failure by scrutinizing the microscopic structure and dynamics of soft systems under various conditions of loading. In particular, we show that the microscopic dynamics is a powerful indicator of the ultimate fate of soft materials, capable of unveiling precursors of failure up to thousands of seconds before any macroscopic sign of weakening.