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Dynamic Allostery of the Catabolite Activator Protein Revealed by Interatomic Forces  [PDF]
Maxime Louet?,Christian Seifert?,Ulf Hensen?,Frauke Gr?ter
PLOS Computational Biology , 2015, DOI: 10.1371/journal.pcbi.1004358
Abstract: The Catabolite Activator Protein (CAP) is a showcase example for entropic allostery. For full activation and DNA binding, the homodimeric protein requires the binding of two cyclic AMP (cAMP) molecules in an anti-cooperative manner, the source of which appears to be largely of entropic nature according to previous experimental studies. We here study at atomic detail the allosteric regulation of CAP with Molecular dynamics (MD) simulations. We recover the experimentally observed entropic penalty for the second cAMP binding event with our recently developed force covariance entropy estimator and reveal allosteric communication pathways with Force Distribution Analyses (FDA). Our observations show that CAP binding results in characteristic changes in the interaction pathways connecting the two cAMP allosteric binding sites with each other, as well as with the DNA binding domains. We identified crucial relays in the mostly symmetric allosteric activation network, and suggest point mutants to test this mechanism. Our study suggests inter-residue forces, as opposed to coordinates, as a highly sensitive measure for structural adaptations that, even though minute, can very effectively propagate allosteric signals.
Hierarchical Fuzzy Feature Similarity Combination for Presentation Slide Retrieval  [cached]
A. Kushki,M. Ajmal,K. N. Plataniotis
EURASIP Journal on Advances in Signal Processing , 2009, DOI: 10.1155/2008/547923
Abstract: This paper proposes a novel XML-based system for retrieval of presentation slides to address the growing data mining needs in presentation archives for educational and scholarly settings. In particular, contextual information, such as structural and formatting features, is extracted from the open format XML representation of presentation slides. In response to a textual user query, each extracted feature is used to compute a fuzzy relevance score for each slide in the database. The fuzzy scores from the various features are then combined through a hierarchical scheme to generate a single relevance score per slide. Various fusion operators and their properties are examined with respect to their effect on retrieval performance. Experimental results indicate a significant increase in retrieval performance measured in terms of precision-recall. The improvements are attributed to both the incorporation of the contextual features and the hierarchical feature combination scheme.
In Vivo Determination of Fluctuating Forces during Endosome Trafficking Using a Combination of Active and Passive Microrheology  [PDF]
Damien Robert,Thi-Hanh Nguyen,Fran?ois Gallet,Claire Wilhelm
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0010046
Abstract: Regulation of intracellular trafficking is a central issue in cell biology. The forces acting on intracellular vesicles (endosomes) can be assessed in living cells by using a combination of active and passive microrheology.
The Comparison of Learning Radiographic Extraoral Anatomic Landmarks through Lecture and blended method(Computer-Assisted teaching and Lecture):An interventional Study  [PDF]
T ahmine Razi,Ali r eza Sighari deljavan
Research and Development in Medical Education , 2013, DOI: 10.5681/rdme.2013.007
Abstract: Introduction: One of the main problems in learning extraoral radiographic anatomic indexes is the long interval between presentation of radiology and human anatomy courses, resulting in forgetting anatomic regions. Therefore, radiographic indexes are formed as complete abstract and transient images in students’ minds; as a result, their learning and retention decrease. The aim of this study was to compare lecture with combination of computer-assisted learning and lecture of extra-oral radiographic landmarks among dental students. Methods: This interventional study was carried out in 2009 on 51 dental students of Tabriz University of Medical Sciences. Students were randomly allocated into two groups. The first group was taught through a teaching method which involved lectures in the classroom. In the second group, a CD was given to the students. The teaching was accomplished through presentation using skull. Six months after finishing the teaching, both groups took a similar test for evaluation of long term learning. The data was analyzed by SPSS 16 using U Mann-Whitney test. Results: There was no significant differences in the mean scores between the two groups in the first exam after teaching (P=0.13), yet it was significant in the second exam (regarding retention) (P=0.006), and average of non-traditional teaching method group (20.89±10.23) was higher than that of lecture group (13.48±6.39). Conclusion: Based on the results, non-traditional technique of teaching was not more effective than the lecture in short-term learning but in longterm learning, non-traditional technique was more effective than the lecture.
Extraoral Ligature of Lingual Artery: Anatomic and Topographic Study
Lins,Carla Cabral dos Santos Accioly; Cavalcanti,Jennecy Sales; do Nascimento,Daniela Lira;
International Journal of Morphology , 2005, DOI: 10.4067/S0717-95022005000300014
Abstract: the lingual artery constitutes one of the branches of the external carotid artery, which is responsible for the vascularization of the tongue and neighbour regions. the hemorrhage caused by a lesion of the lingual artery can occur during a dental procedure (surgical accidents by the use of an instrument or rotating disc), by trauma, biopsy and dental implant. in some cases is difficult to stop the hemorrhage of injured vase, so is necessary to realize the extraoral ligature of this artery. hence, this work studied the anatomic aspects of the lingual artery, by forty-eight dissections of twenty-four corpses settled in formol 10%, aiming to detail the origin, pathway and anatomic relations of the lingual artery in the region of anterior trigone of the neck, and also to measure the distances among the lingual artery and the arteries: facial, superior thyroid and with the bifurcation of the common carotid. the results concluded that the lingual artery is found in a position more inferior than classicaly described, based on the digastric muscle and the hypoglossal nerve; and that the hyoid bone can be used as a point of reference for the surgical access to the lingual artery in the region of the anterior trigone of the neck
Modified Newman and Friedman Extraoral Radiographic Technique
Eshagali Saberi,Ladan Hafezi,Narges Farhadmolashahi,Manoochehr Mokhtari
Iranian Endodontic Journal , 2012,
Abstract: Introduction: Good radiographs are required for endodontic therapy and because some patient’s are intolerant to intraoral films and/or sensors, this can cause complications in endodontic treatment. Extraoral film placement can be used to obtain clinically diagnostic and working radiographs. Materials and Methods: The no. 2 receptor was placed against the model’s cheek and centered in the molar-premolar area. The central beam was directed toward this area from the opposite side. The vertical and horizontal angles that achieved the most accurate radiograph were calculated by trial and error. Results: The best method equated with the patient sitting upright and the Frankfort plane being horizontal to the floor and when the head was tilted 10 degrees toward the side being examined. For the upper posterior teeth the center of the image receptor was placed on the intersection of the ala-tragus and a parasagittal line while the upper border of receptor was parallel to the canthomeatal line; the cone was positioned a negative 25 degrees from the horizontal plane. The central beam was directed from midway between maxillary and mandibular premolars and molars of the opposite side. For the lower posterior teeth, the receptor was placed against the cheek on the side of interest and its lower border was parallel and 2 cm above the inferior border of the mandible. The cone was angled -20 degrees from the horizontal plane while the central beam was directed towards the mandibular molar-premolar region 1 cm below the lower border of the mandibular of the contralateral premolar/molar region. Conclusion: Using this novel technique, high quality images can be acquired for patients who cannot tolerate intraoral radiographs.
Antithrombin III (AT) and recombinant tissue plasminogen activator (R-TPA) used singly and in combination versus supportive care for treatment of endotoxin-induced disseminated intravascular coagulation (DIC) in the neonatal pig
Rachel Davis-Jackson, Hernan Correa, Ronald Horswell, Halina Sadowska-Krowicka, Kathleen McDonough, Chittaranjan Debata, Renee' Gardner, Duna Penn
Thrombosis Journal , 2006, DOI: 10.1186/1477-9560-4-7
Abstract: DIC was induced in twenty-seven neonatal pigs (7 to 14 days of age) by intravenous administration of E. coli endotoxin (800 μg/kg over 30 min). The piglets were divided into 4 groups on the basis of treatment protocol [A: supportive care alone; B: Antithrombin III (AT, 50 μg/kg bolus, 25 μg/kg per hr continuous infusion) and supportive care; C: Recombinant Tissue Plasminogen Activator (R-TPA, 25 μg/kg per hr continuous infusion) and supportive care; D: AT, R-TPA and supportive care] and monitored for 3 primary outcome parameters (survival time, macroscopic and microscopic organ involvement) and 4 secondary outcome parameters (hematocrit; platelet count; fibrinogen level; and antithrombin III level).Compared with supportive care alone, combination therapy with AT and R-TPA resulted in a significant improvement of survival time, hematocrit, AT level, macroscopic and microscopic organ involvement, p < 0.05. Compared with supportive care alone, R-TPA alone significantly reduced macroscopic organ involvement and AT alone increased AT levels.The findings suggest that combining AT, R-TPA and supportive care may prove more advantageous in treating the clinical manifestations of DIC in this neonatal pig model than either single modality or supportive care alone.DIC is a combination of enhanced thrombosis and decreased fibrinolysis. It is precipitated by some underlying disorder, e.g. sepsis, that results in production and release of proinflammatory cytokines. These activate the coagulation cascade, inhibit physiologic anticoagulant pathways, and depress fibrinolysis, resulting in enhanced fibrin formation and impaired fibrin removal [1].Initiated by either contact phase or tissue factor activation, the coagulation cascade is a set of reactions involving multiple coagulation factors and cofactors [2] that result in the generation of thrombin which acts on the fibrin polymer to produce a fibrin clot [3]. This process is subject to regulation by intrinsic inhibitors, e.g. AT an
Loss of permanent mandibular lateral incisor and canine tooth buds through extraoral sinus: Report of a case  [cached]
Kalaskar Ritesh,Damle S
Journal of the Indian Society of Pedodontics and Preventive Dentistry , 2006,
Abstract: Extraoral sinus tract may occur as a result of an inflammatory process associated with the necrotic pulp. Several non odontogenic disorders may also produce an extraoral sinus tract, the differential diagnosis of these clinical findings is of prime importance in providing appropriate clinical care. Presented here is a case report of 4 year old female child with extraoral sinus tract through which the tooth buds of mandibular permanent left lateral incisor and mandibular permanent left canine were lost. The extraoral sinus was due to mandibular left primary canine with class IX fracture (Ellis and Davey′s classification).
Protein Adsorption into Mesopores: A Combination of Electrostatic Interaction, Counterion Release and van der Waals Forces  [PDF]
Sebastian T. Moerz,Patrick Huber
Physics , 2015, DOI: 10.1021/la404947j
Abstract: Bovine heart cytochrome c has been immobilized into the mesoporous silica host material SBA-15 in both its native folded and urea-unfolded state. The comparison of the two folding states' behavior casts doubt on the commonly used explanation of cytochrome c adsorption, i.e. the electrostatic interaction model. A detailed investigation of the protein binding as a function of pH and ionic strength of the buffer solution reveals the complex nature of the protein-silica interaction. Electrostatic interaction, van der Waals forces and entropic contributions by counterion release each contribute to adsorption on the silica pore walls.
Treatment of Class II malocclusion with functional appliances or extraoral headgears? A comparison on monozygotic twins.
Moschos A. Papadopoulos,Anna Alexiou
Hellenic Orthodontic Review , 2012,
Abstract: Despite the well-established use of functional appliances and extraoral headgears for the correction of Class II malocclusion in growing patients, there are only a few studies that have investigated this issue in an evidence-based manner. Twin studies can provide strong evidence in dentistry through the elimination of genetic variables, thus diminishing bias. Thus, aim of this twin study was to evaluate the short and long-term outcomes of the two approaches. Two monozygotic twin girls presenting Class II, division 1 malocclusion were blindly assigned to be treated, the first with a cervical headgear and the second with an activator during the 1st phase of treatment, which was followed by a 2nd phase with full fixed orthodontic appliances. Diagnostic records were collected at 4 different time points during treatment and retention period. For both girls the total treatment and retention periods were 2.75 and 2 years, respectively. The girls appeared with many differences after the end of the 1st phase of treatment, which were attributed to the different skeletal and dentoalveolar changes of each appliance used. However, after the end of total active treatment and after retention, they shared almost identical dental and skeletal characteristics. Although some distinct differences are present immediately following the use of functional appliances and cervical headgears for the correction of Class II malocclusion in growing patients, these are counterbalanced after comprehensive treatment and after retention. Thus, it seems that the initial different short-term results of the two treatment approaches disappear in the long-term.
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