Evaluation of healing criteria for success after periapical surgery

Introduction: In periapical surgery, the absence of standardization between different studies makes it difficult to compare the outcomes. Objective: To compare the healing classification of different authors and evaluate the prognostic criteria of periapical surgery at 12 months. Material and methods: 278 patients (101 men and 177 women) with a mean age of 38.1 years (range 11 to 77) treated with periapical surgery using the ultrasound technique and a 2.6x magnifying glass, and silver amalgam as root-end filling material were included in the study. Evolution was analyzed using the clinical criteria of Mikkonen et al., 1983; radiographic criteria of Rud et al., 1972; the overall combined clinical and radiographic criteria of von Arx and Kurt, 1999; and the Friedman (2005) concept of functional tooth at 12 months of surgery. Results: After 12 months, 87.2% clinical success was obtained according to the Mikkonen et al., 1983 criteria; 73.9% complete radiographic healing using Rud et al. criteria; 62.1% overall success, following the clinical and radiographic parameters of von Arx and Kurt, and 91.9% of teeth were functional. The von Arx and Kurt criteria was found to be the most reliable. Conclusion: Overall evolution according to von Arx and Kurt agreed most closely with the other scales

Käyttäjäkeskeinen kustomointityökalun prototypointi

Käyttäjäkeskeinen ohjelmistokehityson nimensä mukaisesti käyttäjän tarpeista ja vaatimuksista lähtevä ohjelmistojen kehittämistapa. Tällä tavoin halutaan saada selville, millaisia vaikutusmahdollisuuksia hän haluaa. Työ käsittelee tähän perustuvaa toteutusta, jolla käyttäjät voivat toteuttaa eksplisiittistä personointia eli toisin sanoen voivat muokataitse omaa henkilökohtaista tietoaan. Käyttäjille tarjotaan mahdollisuus vaikuttaa tapauskohtaisesti, kuinka hän käyttää personointitietojaan. Työssä luodaan avoimen lähdekoodin väliohjelmistoalustalle (MUPE) personointitiedon kustomointityökalu ja sitä hyödyntävät havainnollistavat palvelut. Tämän pohjana on aikaisemmin suoritettu informaation keruu. Naiden toteutuksien avulla on luotu käyttötapausesimerkkejä, joista voidaan havaita erilaisten personointitietojen käytön vaikutukset käyttäjän kannalta. Työkalun ja havainnollistavien palvelujen avulla luodut esimerkit tarjoavat hyvän ja kestävän pohjan sekä kustomointityökalun että käyttötapausesimerkkien laajentamiselle. Naita esimerkkejä voidaan myös jo suoraan soveltaa todellisissa käyttäjäkeskeisissä kenttätutkimuksissa.

In Search of Corporate Renewal: How to Benefit from Corporate Venturing?

Despite the rapid change in today's business environment there are relatively few studies about corporate renewal. This study aims for its part at filling that research gap by studying the concepts of strategy, corporate renewal, innovation and corporate venturing. Its purpose is to enhance our understanding of how established companies operating in dynamic and global environment can benefit from their corporate venturing activities. The theoretical part approaches the research problem in corporate and venture levels. Firstly, it focuses on mapping the determinants of strategy and suggests using industry, location, resources, knowledge, structure and culture, market, technology and business model to assess the environment and using these determinants to optimize speed and magnitude of change.Secondly, it concludes that the choice of innovation strategy is dependent on the type and dimensions of innovation and suggests assessing market, technology, business model as well as novelty and complexity related to each of them for choosing an optimal context for developing innovations further. Thirdly, it directsattention on processes through which corporate renewal takes place. On corporate level these processes are identified as strategy formulation, strategy formation and strategy implementation. On the venture level the renewal processes are identified as learning, leveraging and nesting. The theoretical contribution of this study, the framework of strategic corporate venturing, joins corporate and venture level management issues together and concludes that strategy processes and linking processes are the mechanism through which continuous corporate renewaltakes place. The framework of strategic corporate venturing proposed by this study is a new way to illustrate the role of corporate venturing as a purposefullybuilt, different view of a company's business environment. The empirical part extended the framework by enhancing our understanding of the link between corporate renewal and corporate venturing in its real life environment in three Finnish companies: Metso, Nokia and TeliaSonera. Characterizing companies' environmentwith the determinants of strategy identified in this study provided a structured way to analyze their competitive position and renewal challenges that they arefacing. More importantly the case studies confirmed that a link between corporate renewal and corporate venturing exists and found out that the link is not as straight forward as indicated by the theory. Furthermore, the case studies enhanced the framework by indicating a sequence according to which the processes work. Firstly, the induced strategy processes strategy formulation and strategy implementation set the scene for corporate venturing context and management processes and leave strategy formation for the venture. Only after that can strategies formed by ventures come back to the corporate level - and if found viable in the corporate level be formalized through formulation and implementation. With the help of the framework of strategic corporate venturing the link between corporaterenewal and corporate venturing can be found and managed. The suggested response to the continuous need for change is continuous renewal i.e. institutionalizing corporate renewal in the strategy processes of the company. As far as benefiting from venturing is concerned the answer lies in deliberately managing venturing in a context different to the mainstream businesses and establishing efficientlinking processes to exploit the renewal potential of individual ventures.

Computational Analysis and Optimization of Real Gas Flow In Small Centrifugal Compressors

Small centrifugal compressors are more and more widely used in many industrialsystems because of their higher efficiency and better off-design performance comparing to piston and scroll compressors as while as higher work coefficient perstage than in axial compressors. Higher efficiency is always the aim of the designer of compressors. In the present work, the influence of four partsof a small centrifugal compressor that compresses heavy molecular weight real gas has been investigated in order to achieve higher efficiency. Two parts concern the impeller: tip clearance and the circumferential position of the splitter blade. The other two parts concern the diffuser: the pinch shape and vane shape. Computational fluid dynamics is applied in this study. The Reynolds averaged Navier-Stokes flow solver Finflo is used. The quasi-steady approach is utilized. Chien's k-e turbulence model is used to model the turbulence. A new practical real gas model is presented in this study. The real gas model is easily generated, accuracy controllable and fairly fast. The numerical results and measurements show good agreement. The influence of tip clearance on the performance of a small compressor is obvious. The pressure ratio and efficiency are decreased as the size of tip clearance is increased, while the total enthalpy rise keeps almost constant. The decrement of the pressure ratio and efficiency is larger at higher mass flow rates and smaller at lower mass flow rates. The flow angles at the inlet and outlet of the impeller are increased as the size of tip clearance is increased. The results of the detailed flow field show that leakingflow is the main reason for the performance drop. The secondary flow region becomes larger as the size of tip clearance is increased and the area of the main flow is compressed. The flow uniformity is then decreased. A detailed study shows that the leaking flow rate is higher near the exit of the impeller than that near the inlet of the impeller. Based on this phenomenon, a new partiallyshrouded impeller is used. The impeller is shrouded near the exit of the impeller. The results show that the flow field near the exit of the impeller is greatly changed by the partially shrouded impeller, and better performance is achievedthan with the unshrouded impeller. The loading distribution on the impeller blade and the flow fields in the impeller is changed by moving the splitter of the impeller in circumferential direction. Moving the splitter slightly to the suction side of the long blade can improve the performance of the compressor. The total enthalpy rise is reduced if only the leading edge of the splitter ismoved to the suction side of the long blade. The performance of the compressor is decreased if the blade is bended from the radius direction at the leading edge of the splitter. The total pressure rise and the enthalpy rise of thecompressor are increased if pinch is used at the diffuser inlet. Among the fivedifferent pinch shape configurations, at design and lower mass flow rates the efficiency of a straight line pinch is the highest, while at higher mass flow rate, the efficiency of a concave pinch is the highest. The sharp corner of the pinch is the main reason for the decrease of efficiency and should be avoided. The variation of the flow angles entering the diffuser in spanwise direction is decreased if pinch is applied. A three-dimensional low solidity twisted vaned diffuser is designed to match the flow angles entering the diffuser. The numerical results show that the pressure recovery in the twisted diffuser is higher than in a conventional low solidity vaned diffuser, which also leads to higher efficiency of the twisted diffuser. Investigation of the detailed flow fields shows that the separation at lower mass flow rate in the twisted diffuser is later than in the conventional low solidity vaned diffuser, which leads to a possible wider flow range of the twisted diffuser.

Numerical and ExperimentalModelling of Gas Flow and Heat Transfer in the Air Gap of An Electric Machine

This work deals with the cooling of high-speed electric machines, such as motors and generators, through an air gap. It consists of numerical and experimental modelling of gas flow and heat transfer in an annular channel. Velocity and temperature profiles are modelled in the air gap of a high-speed testmachine. Local and mean heat transfer coefficients and total friction coefficients are attained for a smooth rotor-stator combination at a large velocity range. The aim is to solve the heat transfer numerically and experimentally. The FINFLO software, developed at Helsinki University of Technology, has been used in the flow solution, and the commercial IGG and Field view programs for the grid generation and post processing. The annular channel is discretized as a sector mesh. Calculation is performed with constant mass flow rate on six rotational speeds. The effect of turbulence is calculated using three turbulence models. The friction coefficient and velocity factor are attained via total friction power. The first part of experimental section consists of finding the proper sensors and calibrating them in a straight pipe. After preliminary tests, a RdF-sensor is glued on the walls of stator and rotor surfaces. Telemetry is needed to be able to measure the heat transfer coefficients at the rotor. The mean heat transfer coefficients are measured in a test machine on four cooling air mass flow rates at a wide Couette Reynolds number range. The calculated values concerning the friction and heat transfer coefficients are compared with measured and semi-empirical data. Heat is transferred from the hotter stator and rotor surfaces to the coolerair flow in the air gap, not from the rotor to the stator via the air gap, althought the stator temperature is lower than the rotor temperature. The calculatedfriction coefficients fits well with the semi-empirical equations and precedingmeasurements. On constant mass flow rate the rotor heat transfer coefficient attains a saturation point at a higher rotational speed, while the heat transfer coefficient of the stator grows uniformly. The magnitudes of the heat transfer coefficients are almost constant with different turbulence models. The calibrationof sensors in a straight pipe is only an advisory step in the selection process. Telemetry is tested in the pipe conditions and compared to the same measurements with a plain sensor. The magnitudes of the measured data and the data from the semi-empirical equation are higher for the heat transfer coefficients than thenumerical data considered on the velocity range. Friction and heat transfer coefficients are presented in a large velocity range in the report. The goals are reached acceptably using numerical and experimental research. The next challenge is to achieve results for grooved stator-rotor combinations. The work contains also results for an air gap with a grooved stator with 36 slots. The velocity field by the numerical method does not match in every respect the estimated flow mode. The absence of secondary Taylor vortices is evident when using time averagednumerical simulation.

Supernumerary molars. A review of 53 cases

Supernumerary molars are not uncommon and may be found nearly anywhere in the dental alveolar arches. A series of 36 patients that presented with 53 supernumerary molars are reviewed. They occurred more frequently in the maxilla (86.8%), had little or no clinical significance, tended to be impacted, and were not associated with the impactation of the third molar. Four cases of maxillary fifth molars are described

Measuring oscillating walking paths with a LIDAR

This work describes the analysis of different walking paths registered using a Light Detection And Ranging (LIDAR) laser range sensor in order to measure oscillating trajectories during unsupervised walking. The estimate of the gait and trajectory parameters were obtained with a terrestrial LIDAR placed 100 mm above the ground with the scanning plane parallel to the floor to measure the trajectory of the legs without attaching any markers or modifying the floor. Three different large walking experiments were performed to test the proposed measurement system with straight and oscillating trajectories. The main advantages of the proposed system are the possibility to measure several steps and obtain average gait parameters and the minimum infrastructure required. This measurement system enables the development of new ambulatory applications based on the analysis of the gait and the trajectory during a walk.

Caciquisme rural i contrautopies pageses. Testimonis d'unes cobles de la Conca de Barberà i del Priorat

Aquest article presenta i estudia un conjunt de cobles de la tradició oral recollides a la Conca de Barberà i al Priorat. Les cançons, creades en el marc de la Restauració, denuncien un conjunt de greuges lligats al caciquisme i al desenvolupament de l’Estat i de les relacions capitalistes que aquest fomenta. Les cobles presenten dos grans registres expressius, que obeeixen a diferents perspectives dels greuges que denuncien. D’una banda tenim unes cobles caracteritzades per una sàtira violenta, dreturera, una sintaxi cantelluda, antítesis primàries, i un recurs viu a les deformacions de l’adversari. En aquests casos, les lletres obeeixen a factors percebuts en la immediatesa de la comunitat, d’acord amb una perspectiva tradicional. D’altra banda, tenim cobles que es caracteritzen per un relaxament còmic i jocós de la sàtira, per una major narrativitat o arromançament, i també per una catarsi benèfica. En aquests casos, les cançons responen a un nou ordre de factors —polítics/política de partit, representants de l’Estat, noves modes estètiques, etc.— que en la societat rural, especialment entre aquells sectors poc introduïts a la modernitat, són percebuts amb una amplitud panoràmica, d’acord amb una ingenuïtat perceptiva, amb un distanciament naïf cap a la realitat. Es tracta d’un ordre de percepcions que informen els trets expressius que hem apuntat quant a aquestes cobles. Unes manifestacions ben il·lustratives d’aquestes darreres composicions són unes contrautopies que recullen, amb voluntat de totalitat, el conjunt d’abusos que pateix la societat pagesa, general o local.

"Chelsea boys": paradigmas sexuales de un cómic "queer"

Más allá del barrio neoyorquino que da título a este serie de volúmenes –aunque en diálogo tanto con su realidad como con sus representaciones anteriores, como Rear Window, dónde se presenta ya como espacio sexualizado–; y más allá del estereotipo gay que la misma expresión representa, Chelsea Boys aparece como un espacio de ruptura de clichés. En el contexto del cómic gay norteamericano que se repasa en este artículo, constituye una propuesta plural, donde la universalidad de las situaciones que representa superan tanto el localismo como la rigidez estereotípica de algunas creaciones anteriores. En él emerge una comunidad queer a través de cuya representación se plantean cuestiones cruciales en y para la/s realidad/es gays.

Surgical reconstruction of TMJ

Certain situations and pathological processes that arise with temporomandibular joint destruction can only be resolved with surgical reconstructive procedures in order to attempt a functional and anatomical rehabilitation of this joint. Many of these situations can be surgically treated with the patient's own autologous tissues. However, in some patients reconstruction is complex and the use of autologous tissues is unadvisable whereas reconstruction utilizing alloplastic materials may be an appropriate alternative. The following report describes 4 clinical cases in which autologous grafts or Christensen joint prosthesis are employed in temporomandibular joint reconstruction

Supernumerary premolars. Report of 10 cases

Supernumerary premolars are 'extra' teeth morphologically belonging to the premolar group. Hyperdontia affecting premolars can be single (when only one supernumerary tooth is found), multiple (if several teeth are involved) or related to a syndrome such as cleidocranial dysplasia. Supernumerary premolars are the third most frequent group of supernumerary teeth, following mesiodens and fourth molars; the prevalence among the general population ranges from 0.09-0.64%. The present study describes 10 cases of supernumerary premolars treated in our Service of Oral and Maxillofacial Surgery of the Dental Clinic of the University of Barcelona. A late onset was demonstrated in one case, contrasting the present pantomograph with another obtained 5 years before. In only one case did the presence of a supernumerary premolar alter normal tooth eruption. Two supernumerary premolars were affected by follicular cysts