Initial Results of an Acetabular Center Axis Registration Technique in Navigated Hip Arthroplasty with Deformed Acetabular Rims!

Abstract

Background

In cementless total hip arthroplasty, imageless computer-assisted navigation is usually used to register the anterior pelvic plane (APP). The accuracy of this method is influenced by the subcutaneous tissues overlying the registration landmarks. On the other hand, the acetabular center axis (ACA) is determined from the acetabular rim. Precise registration of the ACA is possible because of direct palpation using a pointer. Imageless navigation using the ACA usually targets patients with normal acetabular morphology. The aim of this study was to investigate the accuracy of imageless navigation using the ACA instead of the APP in patients with normal or deformed acetabular rims.

Methods

The intraoperative cup position was compared with that obtained from the postoperative computed tomography (CT) images in 18 cases.

Results

The inclination angle derived from the navigation system was 3.4 ± 5.3 degrees smaller and the anteversion angle was 1.4 ± 3.1 degrees larger than those derived from the CT images.

Conclusion

The inclination cup angle of the navigation system was significantly inferior to the true value, particularly in cases with large anterior osteophytes.

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The Pratt Pouch Provides a Three-Fold Access Increase to Antiretroviral Medication for Births outside Health Facilities in Southern Zambia!

Abstract

Introduction:

Modern day antiretroviral therapy allows HIV+ pregnant women to lower the likelihood of viral transmission to their infants before, during, and after birth from 20-45% to less than 5%. In developing countries, where non-facility births may outnumber facility births, infant access to safe antiretroviral medication during the critical first three days after birth is often limited. A single-dose, polyethylene pouch (“Pratt Pouch”) addresses this challenge by allowing the medication to be distributed to mothers during antenatal care.

Methods:

The Pratt Pouch was introduced as part of a one year clinical feasibility study in two districts in Southern Province, Zambia. Participating nurses, community health workers, and pharmacists were trained before implementation. Success in achieving improved antiretroviral medication access was assessed via pre intervention and post intervention survey responses by HIV+ mothers.

Results:

Access to medication for HIV-exposed infants born outside of a health facility increased from 35% (17/51) before the introduction of the pouch to 94% (15/16) after (p<0.05). A non-significant increase in homebirth rates from 33% (pre intervention cohort) to 50% (post intervention cohort) was observed (p>0.05). Results remained below the national average homebirth rate of 52%. Users reported minimal spillage and a high level of satisfaction with the Pratt Pouch.

Conclusion:

The Pratt Pouch enhances access to infant antiretroviral medication in a rural, non-facility birth setting. Wide scale implementation could have a substantial global impact on HIV transmission rates from mother to child.

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Minimal Structural ART Neural Network and Fault Diagnosis Application of Gas Turbine!

Abstract

Adaptive Resonance Theory (ART) model is a special neural network based on unsupervised learning which simulates the cognitive process of human. However, ART1 can be only used for binary input, and ART2 can be used for binary and analog vectors which have complex structures and complicated calculations. In order to improve the real-time performance of the network, a minimal structural ART is proposed which combines the merits of the two models by subsuming the bottom-up and top-down weight. The vector similarity test is used instead of vigilance test. Therefore, this algorithm has a simple structure like ART1 and good performance as ART2 which can be used for both binary and analog vector classification, and it has a high efficiency. Finally, a gas turbine fault diagnosis experiment exhibits the validity of the new network.

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Treatment of Male Urinary Incontinence with An Adjustable Implantable Medical Device: Ustrap!

Abstract

Introduction and Objectives: Our aim is to develop a device which is simpler, less expensive, but equally or more effective than currently available devices including the artificial urinary sphincter.

Method: Based on our knowledge of and experience with other devices we designed the Ustrap. The theoretical advantages of our approach are described as is the development to the current (3^rd) version.

Results: For version #1, implanted in 6 patients, the 5 year follow up includes 2 improved, 2 unchanged, 2 required AUS. For version #2 implanted in 4 patients, 2 year follow up shows 3 improved, 1 failure.

Conclusions: The Ustrap has unique features which distinguish it from current devices. A proposed multicenter prospective clinical trial of version #3 is awaiting approval.

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IgG4-Related Lung Disease Associated with Usual Interstitial Pneumonia!

Abstract

We report a case of immunoglobulin(Ig)G4-related disease with the radiologic and histopathological manifestations resembling usual interstitial pneumonia (UIP). The patient was a 62-year-old man who presented with progressive dyspnea of insidious onset. High resolution computed tomography of the chest showed lower-lobe predominant peripheral reticulation and traction bronchiectasis but no honeycomb change. Microscopic examination of the surgical lung biopsy showed characteristic features of UIP including architectural distortion by fibrosis with peripheral and paraseptal accentuation, scattered fibroblast foci and microscopic honeycomb change. In addition there were prominent multifocal lymphoplasmacytic infiltrates with a marked increase of IgG4-positive plasma cells (79 per high power field in hot spots) and high IgG4/IgG ratio (up to 67%). The serum IgG4 level was elevated at 760 mg/dl (reference range 9-89), with normal levels for the other IgG subclasses and negative serologic markers for autoimmune diseases. The patient’s symptoms improved significantly with oral corticosteroid treatment.

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Ability of Three Endodontic Sealers to Fill the Root Canal System in Association with Gutta-Percha!

Abstract

Introduction: The present study compared the ability of the endodontic sealers AH Plus, Pulp Canal Sealer and EndoREZ to fill the root canal system in association with gutta-percha.

Methods: Ninety mandibular premolars were accessed, prepared and divided into three groups of 30 teeth each, according to the sealer used to fill the canals: AH Plus, Pulp Canal Sealer and EndoREZ. All the teeth were filled using the continuous wave of condensation technique. The specimens were then decalcified, dehydrated, rendered transparent, and analyzed by three independent evaluators with 8x magnification. Chi-squared test (χ², p < 0.05) was used to compare the groups in relation to the totally filled, the partially filled and the non filled ramifications. The same test was used to compare the directions of filled ramifications and the number of ramifications among the three thirds of the roots.

Results: EndoREZ filled a significantly higher number of ramifications than AH Plus and Pulp Canal Sealer (χ², p < 0.05). All the groups showed higher number of totally filled ramifications than partially filled and unfilled ramifications. The ramifications were more frequently detected in the apical third, followed by medium and coronal thirds, respectively (χ², p< 0.05). The ramifications were more frequently detected towards lingual direction (χ², p < 0.05).

Conclusion: EndoREZ presented higher ability to fill the root canal system in association with gutta-percha when compared to AH Plus and Pulp Canal Sealer. The ramifications were more frequently detected in the apical third, running in a lingual direction.

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Calcium-Enriched Mixture Pulpotomy of Primary Molar Teeth with Irreversible Pulpitis. A Clinical Study!

Abstract

Objectives: To evaluate the outcome of vital pulp therapy in primary teeth with irreversible pulpitis by using calcium-enriched mixture (CEM) cement according to clinical and radiographic assessment.

 

Participants and Methods: Fifty primary molar teeth with irreversible pulpitis in 50 children aged 6-8 years underwent pulpotomy using CEM cement as the dressing material. Following pulpotomy, pain intensity was evaluated by use of a visual analog scale at 1 and 7 days from the treatment and in clinical appointments at 3, 6 and 12 months after baseline. Radiographic evaluation was performed at 6 and 12 months. Data were analyzed using the McNemar test.

 

Results: A total of 42 children (mean age 7.26 ± 0.82 year) completed the study. After one day treatment 56 % of children reported complete relief of pain and after 7 days 62% reported the same. However, two children complained of increased pain 1 day after treatment. None of the children reported pain in the subsequent appointments. One child complained of tenderness in percussion after 6 months. Pulp canal obliteration was the most common change in the radiographic assessment. There was no significant difference between clinical (92.8%) and radiographic (90.4%) success (p=0.990).

Conclusion: Pulpotomy using CEM cement could present a successful treatment in primary molar teeth with irreversible pulpitis.

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The Use of the Digital Smile Design Concept as an Auxiliary Tool in Aesthetic Rehabilitation: A Case Report!

Abstract

The digital smile design is a practical diagnosis method that can assist the clinician to visualize and measure dentogingival discrepancies. This clinical report aims to present the associated steps, from the diagnosis of the alterations diagnosis through to the final aesthetic result. A 37-years-old female patient presented as her main complaint the tooth form and colour discrepancies. Applying the digital smile design principle, the necessary measures for a harmonic smile correction could be accurately determined. The initial diagnosis led to a wax up of the master cast that was duplicated in acrylic resin directly in the mouth. This temporary restoration guided the periodontal surgery and the final pressed ceramic crown restoration. We conclude that the digital smile design concept seems to be a useful tool to achieve a satisfactory aesthetic result.

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Experimental Studies on Cohesion of Carbon Fibre Reinforced Polymer for Reinforcement of Bridge Deck Slabs!

Abstract

Bridge deck slabs reinforced by carbon fibre reinforced polymer (CFRP) are subjected to a number of problems related to cohesion, such as slippage, disengaging, and debonding. In order to address such problems, we conducted indoor shear, stretching, and debonding tests, analysed the change rule of cohesion in these three different environments, and determined the optimum construction technique for improving the cohesion of CFRP. We found that to obtain acceptable shear strength, manufactured sand should be spread on the surface of the impregnating resin adhesive. Soaking, freeze thawing, and wheel grinding processes affected the tensile strength of the interface, which was related linearly to the shear strength of the interface. Following wheel grinding on an asphalt surface at high temperatures, the test value for the bearing-debonding capacity on a test slab was unchanged, and the effectiveness of the CFRP was still apparent. The influence of high-temperature wheel grinding can be ignored. This study can serve as a reference for the design of reinforced bridge deck slabs.

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