Hydrodynamic studies of aqueous two-phase systems in millichannels

Liquid-liquid segmented flows in microchannels have been extensively investigated in the context of nanoparticle synthesis. The enhanced mixing in the slugs results in monodispersed particles. Earlier studies have focused on Organic-Aqueous Systems (OAS). The nanoparticles synthesized in the presence of organic solutions have limited applications. An alternative green route for the synthesis can be developed using an Aqueous Two-Phase System (ATPS). These systems are characterized by interfacial tensions, which are two orders of magnitude lower than typical organic aqueous systems. In this work, flow patterns and hydrodynamics of ATPS are investigated as a first step. Polyethylene glycol -trisodium citrate system was chosen as ATPS. The objective of this work is to see if any new physics arises in an ATPS system. The low interfacial tension results in high Capillary numbers (Ca >> 3) in a microfluidic system. Consequently, the flow observed here is parallel or core-annular. However, in a millichannel, the capillary number becomes lower (Ca << 1) for an ATPS system. In this work, experiments were carried out in a millichannel to span different flow patterns. The pattern formation was analyzed and classified into three categories, i.e., slug flow (interfacial tension dominated), transition flow, and core annular flow (inertia dominated). Flow regime maps based on the Reynolds number, Capillary number, and Weber number of each phase were found to be qualitatively similar to those of OAS. Simulations were performed for various interfacial tension values. An interfacial tension value of 1.25x10-4 N/m was found to yield slug sizes which fitted well with the experimental data. Film thickness was measured experimentally and with simulations compared favorably with the correlations available in the literature for OAS

Handheld computers and the 21(st )century surgical team: a pilot study

BACKGROUND: The commercial development and expansion of mobile phone networks has led to the creation of devices combining mobile phones and personal digital assistants, which could prove invaluable in a clinical setting. This pilot study aimed to look at how one such device compared with the current pager system in facilitating inter-professional communication in a hospital clinical team. METHODS: The study looked at a heterogeneous team of doctors (n = 9) working in a busy surgical setting at St. Mary's Hospital in London and compared the use of a personal digital assistant with mobile phone and web-browsing facilities to the existing pager system. The primary feature of this device being compared to the conventional pager was its use as a mobile phone, but other features evaluated included the ability to access the internet, and reference data on the device. A crossover study was carried out for 6 weeks in 2004, with the team having access to the personal digital assistant every alternate week. The primary outcome measure for assessing efficiency of communication was the length of time it took for clinicians to respond to a call. We also sought to assess the ease of adoption of new technology by evaluating the perceptions of the team (n = 9) to personal digital assistants, by administering a questionnaire. RESULTS: Doctors equipped with a personal digital assistant rather than a pager, responded more quickly to a call and had a lower of failure to respond rate (RR: 0.44; 95%CI 0.20–0.93). Clinicians also found this technology easy to adopt as seen by a significant reduction in perceptions of nervousness to the technology over the six-week study period (mean (SD) week 1: 4.10 (SD 1.69) vs. mean (SD) week 6: 2.20 (1.99); p = 0.04). CONCLUSION: The results of this pilot study show the possible effects of replacing the current hospital pager with a newer, more technologically advanced device, and suggest that a combined personal digital assistant and mobile phone device may improve communication between doctors. In the light of these encouraging preliminary findings, we propose a large-scale clinical trial of the use of these devices in facilitating inter-professional communication in a hospital setting

A Proposed Model

Rocha-Penedo, R., Cruz-Jesus, F., & Oliveira, T. (2021). Opposite Outcomes of Social Media Use: A Proposed Model. In S. K. Sharma, Y. K. Dwivedi, B. Metri, & N. P. Rana (Eds.), Re-imagining Diffusion and Adoption of Information Technology and Systems: A Continuing Conversation - IFIP WG 8.6 International Conference on Transfer and Diffusion of IT, TDIT 2020, Proceedings (pp. 524-537). (IFIP Advances in Information and Communication Technology; Vol. 618). Springer. https://doi.org/10.1007/978-3-030-64861-9_46Social media are probably one of the most influential and disruptive technology of the present times. It is ubiquitous and has the capability to influence virtually every aspect of one’s life while, at the same time, also influence the way firms and public organizations operate and communicate with individuals. Although there is a plethora of studies in the IS literature focused on SM adoption and outcomes, studies hypothesizing positive and negative outcomes together are scarce. We propose a comprehensive research model to shed light on SM positive and negative outcomes, and how these affect one’s happiness. We also explore how personality traits can influence these relationships.authorsversionpublishe

Judgment of the Humanness of an Interlocutor Is in the Eye of the Beholder

Despite tremendous advances in artificial language synthesis, no machine has so far succeeded in deceiving a human. Most research focused on analyzing the behavior of “good” machine. We here choose an opposite strategy, by analyzing the behavior of “bad” humans, i.e., humans perceived as machine. The Loebner Prize in Artificial Intelligence features humans and artificial agents trying to convince judges on their humanness via computer-mediated communication. Using this setting as a model, we investigated here whether the linguistic behavior of human subjects perceived as non-human would enable us to identify some of the core parameters involved in the judgment of an agents' humanness. We analyzed descriptive and semantic aspects of dialogues in which subjects succeeded or failed to convince judges of their humanness. Using cognitive and emotional dimensions in a global behavioral characterization, we demonstrate important differences in the patterns of behavioral expressiveness of the judges whether they perceived their interlocutor as being human or machine. Furthermore, the indicators of interest displayed by the judges were predictive of the final judgment of humanness. Thus, we show that the judgment of an interlocutor's humanness during a social interaction depends not only on his behavior, but also on the judge himself. Our results thus demonstrate that the judgment of humanness is in the eye of the beholder

Standardization of the NEO-PI-3 in the Greek general population

BACKGROUND: The revised NEO Personality Inventory (NEO-PI-3) includes 240 items corresponding to the Big Five personality traits (Extraversion, Agreeableness, Conscientiousness, Neuroticism, and Openness to Experience) and subordinate dimensions (facets). It is suitable for use with adolescents and adults (12 years or older). The aim of the current study was to validate the Greek translation of the NEO-PI-3 in the general Greek population. MATERIAL AND METHODS: The study sample included 734 subjects from the general Greek population of whom 59.4% were females and 40.6% males aged 40.80 +/- 11.48. The NEO-PI-3 was translated into Greek and back-translated into English, and the accuracy of the translation was confirmed and established. The statistical analysis included descriptive statistics, confirmatory factorial analysis (CFA), the calculation of Cronbach's alpha, and the calculation of Pearson product-moment correlations. Sociodemographics groups were compared by ANOVA. RESULTS: Most facets had Cronbach's alpha above 0.60. Confirmatory factor analysis showed acceptable loading of the facets on their own hypothesized factors and very good estimations of Cronbach's alphas for the hypothesized factors, so it was partially supportive of the five-factor structure of the NEO-PI-3.The factors extracted with Procrustes rotation analysis can be considered reasonably homologous to the factors of the American normative sample. Correlations between dimensions were as expected and similar to those reported in the literature. DISCUSSION: The literature suggests that overall, the psychometric properties of NEO-PI-3 scales have been found to generalize across ages, cultures, and methods of measurement. In accord with this, the results of the current study confirm the reliability of the Greek translation and adaptation of the NEO-PI-3. The inventory has comparable psychometric properties in its Greek version in comparison to the original and other national translations, and it is suitable for clinical as well as research use

A Comparative Study Using Dexmedetomidine and Clonidine as Adjuvants with Levobupivacaine in Axillary Brachial Plexus Block for Upper Limb Surgeries

Introduction: The axillary approach to the brachial plexus is the most popular because of its ease, reliability, and safety. Blockade occurs at the level of the terminal nerves. Alpha2-agonists are mixed with local anaesthetic agents to extend the duration of spinal, extradural and peripheral nerve blocks. The aim of the study is to compare the effects of clonidine and that of dexmedetomidine as adjuvants to levobupivacaine in axillary brachial plexus block. The onset time and duration of sensory and motor block, duration of analgesia, sedation score and haemodynamic parameters were studied in both groups. Methods: A prospective, double blinded, randomized clinical study was conducted at Department of Anaesthesia, Kamineni Academy of Medical Sciences and Research Center on eighty ASA class I and II adult patients undergoing upper limb surgeries under ultrasound guided axillary brachial plexus block. Patients were randomly divided into two equal groups, group LD (n=40): will receive 25ml of 0.5 % of levobupivacaine +1 μg/kg dexmedetomidine, and group LC (n=40) will receive 25ml of 0.5 % levobupivacaine +1 μg/kg of clonidine. The whole solution made up to 30 ml in each group by adding sterile water for injection. Haemodynamic parameters (heart rate, non invasive blood pressure, oxygen saturation), onset time and duration of sensory, motor block, duration of analgesia and, sedation score were recorded and then compared between the groups. Results: There was no statistically significant difference (P&gt;0.05) in haemodynamic parameters. Onset time of sensory and motor block were significantly faster (P&lt;0.05), duration of sensory and motor block and duration of analgesia significantly longer (P &lt;0.05) in dexmedetomidine group (group LD) when compared to clonidine group (group LC). The sedation scores were also better in group LD (P&lt;0.05). Conclusion: Dexmedetomidine is a better adjuvant than clonidine when added to levobupivacaine in axillary brachial plexus block, as it hastens the onset time of sensory and motor block, prolongs the duration of sensory and motor blockade as well as the duration of analgesia, with better intraoperative sedation without causing any haemodynamic variations