Changing QRS Morphology: What is the mechanism?

ECG in sinus rhythm with ventricular preexcitation and changing QRS morphology was seen that was initially interpreted as the multiple accessory pathway from elsewhere. (Figure 1A). The following mechanisms are potentially involved in the electrogenesis of changing QRS morphology in WPW syndrome: 1) multiple accessory pathways1; 2) simultaneous occurrence of aberrant atrioventricular conduction with accessory pathway conduction 2; 3) ventricular fusion of preexcited sinus impulse with ectopic impulse. Electrophysiologic study showed short PR (75 ms) interval with wide QRS (152 ms) and negative HV (-12 ms) interval. No change in delta wave polarity was observed during HRA and CS pacing. In full preexcitation, no breakthrough was seen in the CS. During incremental ventricular pacing, atrial breakthrough site is initially recorded on the HRA catheter and then changed to distal pole of CS catheter with progressive decrease in pacing cycle length. During ventricular pacing at cycle length of 500 ms (S1), earliest atrial activity is recorded on HRA catheter. Changing QRS could not be explained by presence of multiple APs because only right-sided AP had bidirectional conduction and no distal CS breakthrough was seen simultaneous with changing QRS morphology. The possibility of aberrant conduction is excluded by presence of negative HV interval in the beats with differing QRS morphology. No sinus cycle length variation before and after the beats with different morphologies are against the occurrence of functional LBBB. The prematurity of ventricular electrogram in His recording catheter with variable HV (H-electrogram is recorded after V-electrogram in second beat and before V-electrogram in third beat) and fixed V-RB intervals (interval from ventricular electrogram in His to the RB potential) are compatible with ventricular fusion of preexcited sinus impulse with ectopic ventricular impulse originating from parahissian area (explaining LBBB and inferior axis morphology of the beats with changing QRS) but not from the His bundle or RBB itself (because H-electrogram and RB potential is recorded after V-electrogram in the second beat with greater degree of ventricular fusion)(Figure 1B)

Learning Organizations is more successful Than Others

Knowledge and learning are among the important factors in organizations and are inevitable for their survival. Organizations are the result of the way of thinking and acting of their members. Therefore, if we want an organization to change, we should give enough time to individuals to change their way of thinking and acting. It is obvious that we cannot achieve such changes by intensifying training courses and/or the method of order and control management. Organizational learning requires introducing new management ideas, methods and tools. By providing opportunities for doing new works, members of the organization will achieve a stable capacity for change. Organizational learning has been paid increasing attention by the organizations which are interested in competitive advantage, innovation, and efficiency. Traditionally, learning has been defined as a process by which individuals will acquire new knowledge and insight as a result of changing their behaviors and actions. Learning organization is an organization which is managed consciously towards learning, and learning is an important component in its values, visions, objectives, evaluations, and daily operations. Learning is a process which includes quadripartite mechanisms which themselves include learning environment, recognition of developmental and learning needs, realization of developmental and learning needs, and utilizing learning in work environment. To focus on learning means to concentrate on making changes in an extensive level of individuals, groups, and organizations. Since environmental change is a constant and continuous action and an open and unpredictable process in nature, learning plays a critical and sensitive role in aligning organizational forces in this unreliable environment and moving towards a glorious, pervasive, and learning organization. Keywords: Learning, learning Organizations, Human Resource

nPIV velocity measurement of nanofluids in the near-wall region of a microchannel

Colloidal suspensions of nano-sized particles in a base fluid, nanofluids, have recently gained popularity as cooling fluids mainly due to their enhanced heat transfer capabilities. However, there is controversy in the literature on the reported properties of nanofluids and their applicability, especially since there is no fundamental understanding that explains these enhancements. A better understanding of these fluids and how they interact with a solid boundary may be achieved by a detailed near-wall fluid flow study at nanoscale. This work presents for the first time the near-wall velocity measurements for nanofluids using nanoparticle image velocimetry. This novel technique uses evanescent illumination in the solid–fluid interface to measure near-wall velocity field with an out-of-plane resolution on the order of O(100 nm). Nanofluids of different concentrations were prepared by dispersing silicon dioxide particles (10 to 20 nm) in water as the base fluid. Initially, viscosity measurements were conducted for the prepared nanofluids. The near-wall velocity data were then measured and compared with that of the base fluid at the same flow condition. It was observed that even though nanofluid viscosity had increased with particle loading, the near-wall velocity values were similar to that of the base fluid for a given flow rate. Together, these measurements vindicate the homogenous and Newtonian characteristics of the nanofluids in the near-wall region. Despite the low particle concentrations investigated, the present work also discusses the complexity involved in utilizing the methodology and possible errors arising during experimentation so as to implement this measurement tool more effectively in the future

Essential Thrombocytosis Following Multiple Psychic Traumas

The associations between exposure to traumatic events and psychiatric disorders such as posttraumatic stress disorder (PTSD), depression, and anxiety have been established. It is important that clinicians notice to this phenomenon and avoid from inappropriate interpretations and additional laboratory tests. Here, a case of 45-year-old man with Essential thrombocytosis developed after multiple psychic traumas was introduced

Chlorido(1H-imidazole-κN 3)bis­(triphenyl­phosphane-κP)copper(I)

In the title complex, [CuCl(C3H4N2)(C18H15P)2], the coordination geometry around CuI is distorted tetra­hedral formed by two triphenyl­phosphane ligands, an imidazole ligand and a chloride group. An intra­molecular C—H⋯Cl inter­action occurs. The crystal packing is stabilized by inter­molecular N—H⋯Cl hydrogen bonds, which form an extended chain parallel to [010]

The efficacy of the emotion regulation intervention on coping styles in patients with alexithymia

Background and Purpose: Alexithymia that is known as a kind of insufficiency in emotion regulation is a dangerous factor for many mental disorders. This study is conducted to evaluate the effectiveness of emotion regulation intervention on coping styles in patients with the symptoms of alexithymia.Materials and methods: The research method is experimental with the pretest – post-test and control group. The study population has included the B.A students of Kharazmi University in the year 2014. The study sample has been consisted of 40 students who had the symptoms of alexithymia in the Kharazmi University in the year 2014; these students in the scale of alexithymia have been scored higher than 60 and during the interviews they have been approved in terms having the symptoms of alexithymia and the lack of accompanying symptoms. Then, by getting their permission, these people have been randomly assigned in two intervention and control groups (N =20). But with the primary reduction of the sample, the number of participants in each group has been reduced to 12 people. The intervention group has been trained in 8 sessions of emotion regulation intervention training that each session has been lasted for 90 minutes per week. But the control group did not receive any training programs. The research tools have been consisted of the Tehran Coping Styles Inventory of Karvar et al (1989) and Toronto alexithymia of Besharat (2007). After collecting the data, in addition to using the descriptive statistics, the covariance analysis has been used to analyze the data.Results: The data analysis has shown that the emotion regulation intervention will significantly increase the use of problem-focused coping style (p<0.05).  Conclusion: According to the results of this study, the emotion regulation intervention can be an effective method to improve the problems that are associated with alexithymia in the patients who have alexithymia, and it can be considered as a preventive intervention to prevent the bigger problems of the people who have alexithymia

Effect of two prophylaxis methods on adherence of Streptococcus mutans to microfilled composite resin and giomer surfaces

Objectives: Surface attributes of a restoration play an important role in adherence of plaque bacteria. Prophylaxis methods may be involved in modification of or damaging the restoration surface. The aim of the present study was to evaluate the effect of two prophylaxis methods on adherence of Streptococcus mutans to the surface of two restorative materials. Study design: A total of 60 specimens were prepared from each material; a microfilled composite resin (HelioProgress) and a giomer (Beautifil II). For each material, the specimens were randomly divided into three groups (n=20). Group 1: no prophylaxis treatment (control); Group 2: prophylaxis with pumice and rubber cup; Group 3: prophylaxis with air-powder polishing device (APD). The surfaces of selected specimens from each group were evaluated under a scanning electron microscope (SEM), and the surface topography formed by the two prophylaxis methods was determined by atomic force microscopy (AFM). Adherence of Streptococcus mutans to the surface of specimens was determined by the plate counting method following immersion in a bacterial innoculum for 4 hours, rinsing and sonication. Data were analyzed by two-way ANOVA and post hoc Tukey test for multiple comparisons. Statistical significance was set at P<0.05. Results: Bacterial adherence was significantly affected by both factors: restorative material type and prophylaxis method (P<0.0005). Mean bacterial adhesion was significantly higher in composite groups compared to corresponding giomer groups. Within each material, bacterial adherence was significantly lower in the control group compared to prophylaxis groups. Prophylaxis with pumice and rubber cup resulted in a significantly lower bacterial adherence compared to prophylaxis with APD. Conclusions: Based on the results of the present study, giomer specimens demonstrated lower bacterial adherence compared to composite resin specimens. In both materials, the highest bacterial adherence was observed with prophylaxis with APD, pumice and rubber cup and the control group, respectively. © Medicina Oral S. L