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Technical Advantages (technical + advantage)

Distribution by Scientific Domains

Medical Sciences	54%
Earth and Environmental Science	18%

Selected Abstracts

Magnification devices for endodontic therapy

AUSTRALIAN DENTAL JOURNAL, Issue 4 2009
M Del Fabbro
Background:, After the introduction of microsurgical principles in endodontics, involving new techniques for root canal treatment, there has been a continuous search for enhancing the visualization of the surgical field. It would be interesting to know if the technical advantages for the operator brought in by magnification devices like surgical microscope, endoscope and magnifying loupes, are also associated with advantages for the patient, in terms of improvement of clinical and radiographic outcomes. Objectives:, The purpose of this systematic review was to evaluate and compare the effects of endodontic treatment performed with the aid of magnification devices versus endodontic treatment without magnification devices. We also aimed at comparing among them the different magnification devices used in endodontics (microscope, endoscope, magnifying loupes). Search strategy:, The Cochrane Oral Health Group Trials Register, CENTRAL, MEDLINE and EMBASE were searched with appropriate search strategies. Handsearching included nine dental journals. The bibliographies of relevant clinical trials and relevant articles were checked for identifying studies outside the handsearched journals. Seven manufacturers of instruments in the field of endodontics and/or endodontic surgery, as well as the authors of the identified randomized controlled trials (RCTs) were contacted in order to identify unpublished or ongoing RCTs. There were no language restrictions. The last electronic search was conducted on 2nd April 2009, and the last handsearching was undertaken on 31st January 2009. Selection criteria:, All randomized and quasi-randomized trials comparing endodontic therapy performed with or without using one or more types of magnification device, as well as randomized and quasi-randomized trials comparing two or more magnification devices used as an adjunct to endodontic therapy were considered. Data collection and analysis:, Screening of studies and data extraction were conducted independently and in duplicate. The Cochrane Collaboration statistical guidelines were to be followed for data synthesis. Main results:, No trial could be included in the present review. All of the prospective trials that were identified, all dealing with endodontic surgery, had to be excluded for various reasons. Only one RCT was identified comparing three magnificators (magnifying loupes, surgical microscope, endoscope) in endodontic surgery. No RCT was found that compared the outcome of endodontic therapy using or without using a given magnification device. Authors' conclusions:, No objective conclusion can be drawn from the results of this review as no article was identified in the current literature that satisfied the criteria for inclusion. It is unknown if and how the type of magnification device affects the treatment outcome, considering the high number of factors that may have a significant impact on the success of endodontic surgical procedure. This should be investigated by further long-term RCTs with large sample size. Technical advantages of magnificators have been widely reported in low evidence level studies, but they should be systematically addressed to know if there can be the clinical indication for using a given magnification device for specific clinical situations, such as for molar teeth, or if they can all be used interchangeably. Well-designed RCTs should also be performed to determine the true difference in terms of treatment success rates between using or not using a magnification device in both conventional and surgical endodontic treatment, if any exist. Plain language summary:, Magnification devices for endodontic therapy. There are no data to draw a sound conclusion on the effect of adopting either a microscope, an endoscope, or magnifying loupes for better visualization in endodontic therapy, in terms of clinical outcomes. Though the use of magnification devices has often been associated with technical advantages for the operator and with an improved management of the root canal due to a better visualization of the operative field, it still has to be demonstrated that their use may lead to an improved treatment success rate. More long-term well-designed randomized trials with a large sample size are urgently needed to address the issues of the present review. [source]

Screening and prevention of diabetic blindness

ACTA OPHTHALMOLOGICA, Issue 4 2000
Einar Stefánsson
ABSTRACT. : Diabetic eye disease remains a major cause of blindness in the world. Laser treatment for proliferative diabetic retinopathy and diabetic macular edema became available more than two decades ago. The outcome of treatment depends on the timing of laser treatment. The laser treatment is optimally delivered when high-risk characteristics have developed in proliferative retinopathy or diabetic macular edema and before this has significantly affected vision. Laser treatment is usually successful if applied during this optimal period whereas the treatment benefit falls sharply if the treatment is applied too late. In order to optimize the timing of laser treatment in diabetic eye disease screening programs have been established. The oldest screening program is 20 years old and several programs have been established during the last decade. In this paper the organisation and methods of screening programs are described including direct and photographic screening. The incidence and prevalence of blindness is much lower in populations where screening for diabetic eye disease has been established compared to diabetic populations without screening. Technical advantages may allow increased efficiency and telescreening. From a public health standpoint screening for diabetic eye disease is one of the most cost effective health procedures available. Diabetic eye disease can be prevented using existing technology and the cost involved is many times less than the cost of diabetic blindness. [source]

The major- and trace-element whole-rock fingerprints of Egyptian basalts and the provenance of Egyptian artefacts

GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 7 2001
John D. Greenough
Discrimination diagrams have been developed that source Egyptian basaltic artefacts using whole-rock major element geochemistry. These include K2O versus SiO2, TiO2 and P2O5 against MgO/Fe2O3t (total Fe as Fe2O3), and a discriminant analysis diagram using SiO2, Fe2O3t, CaO, and MnO. A complementary set of diagrams uses easily obtained trace element data (Nb/Y versus Zr/Nb; Zr [ppm] versus Rb/Sr; TiO2 [wt % volatile free] versus V; and Cr [ppm] versus Zr/Y) to determine the bedrock sources. These diagrams have been applied to seven First Dynasty basalt vessels (Abydos), two Fourth Dynasty basalt paving stones (Khufu's funerary temple, Giza), and two Fifth Dynasty paving stones (Sahure's complex, Abu Sir). They show that the bedrock source for all the artefacts was the Haddadin flow in northern Egypt. Multidimensional scaling and cluster analysis applied to the whole-rock data (major elements and trace elements together) and previously published mineral fingerprinting studies confirm these results. Comparing mineral versus whole-rock fingerprinting techniques, a major advantage of the former is the small sample size required (0.001 g compared to , 0.1 g). Analytical costs are similar for both methods assuming that a comparison (bedrock) database can be assembled from the literature. For most archaeological problems, a whole-rock bedrock database is more likely to exist than a mineral database, and whole-rock analyses on artefacts will generally be easier to obtain than mineral analyses. Whole-rock fingerprinting may be more sensitive than mineral-based fingerprinting. Thus, if sample quantity is not an issue, whole-rock analysis may have a slight cost, convenience, and technical advantage over mineral-based methods. Our results also emphasize that the Egyptians cherished their Haddadin basalt flow and used it extensively and exclusively for manufacturing basalt vessels and paving stones for at least 600 years (,3150 B.C. to 2500 B.C., approximate ages of the vessels and Abu Sir paving stones, respectively). © 2001 John Wiley & Sons, Inc. [source]

Evidence-Based Review of the Use of Cryosurgery in Treatment of Basal Cell Carcinoma

DERMATOLOGIC SURGERY, Issue 6 2003
Agnieszka Kokoszka MD
Background. Cryosurgery has been used to treat basal cell carcinoma (BCC), and it has many technical advantages over other methods. It is therefore important to establish its efficacy as a treatment for BCC. Objective. To review systematically the body of literature reporting on the efficacy of cryosurgery of BCC in terms of recurrence rates and cosmetic results. Methods. A review is given of MEDLINE, EMBASE, CancerLit, and the Cochrane Database of Systematic Reviews for studies that examined cryosurgery in treatment of BCC patients. Results. We found 13 noncontrolled prospective studies and 4 randomized clinical trials comparing cryosurgery to other methods of treatment for BCC. Because of the inability to double blind or placebo control treatment of BCC, none of the studies met criteria for A or B grade evidence, as defined by Sackett. Therefore, all studies were assigned grade C. Conclusions. According to the best evidence, recurrence rates of BCC treated with cryosurgery are low (less than 10%). Except in one study, recurrence rates are calculated based on clinical, rather than histologic diagnosis, which may cause the rates to appear somewhat lower than they actually are, especially with a short follow-up period. Cosmetic results of cryosurgery treatment reported in literature are described as good by most investigators. Overall, there are sufficient data to consider cryosurgery as a reasonable treatment for BCC. There are no good studies, however, comparing cryosurgery with other modalities, particularly with Mohs surgery, excision, or electrodesiccation and curettage so that no conclusion can be made whether cryosurgery is as efficacious as other methods. Also, there is no evidence on whether curetting the lesions before cryosurgery affects the efficacy of treatment. [source]

Optical imaging of infants' neurocognitive development: Recent advances and perspectives

DEVELOPMENTAL NEUROBIOLOGY, Issue 6 2008
Yasuyo Minagawa-Kawai
Abstract Near-infrared spectroscopy (NIRS) provides a unique method of monitoring infant brain function by measuring the changes in the concentrations of oxygenated and deoxygenated hemoglobin. During the past 10 years, NIRS measurement of the developing brain has rapidly expanded. In this article, a brief discussion of the general principles of NIRS, including its technical advantages and limitations, is followed by a detailed review of the role played so far by NIRS in the study of infant perception and cognition, including language, and visual and auditory functions. Results have highlighted, in particular, the developmental changes of cerebral asymmetry associated with speech acquisition. Finally, suggestions for future studies of neurocognitive development using NIRS are presented. Although NIRS studies of the infant brain have yet to fulfill their potential, a review of the work done so far indicates that NIRS is likely to provide many unique insights in the field of developmental neuroscience. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008 [source]

Drug substances presented as sulfonic acid salts: overview of utility, safety and regulation

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 3 2009
David P. Elder
Abstract Objectives Controlling genotoxic impurities represents a significant challenge to both industry and regulators. The potential for formation of genotoxic short-chain alkyl esters of sulfonic acids during synthesis of sulfonic acid salts is a long-standing regulatory concern. This review provides a general overview of the utility of sulfonic acids as salt-forming moieties and discusses strategies for effectively minimizing the potential for alkyl sulfonate formation during the synthesis and processing of sulfonate salt active pharmaceutical ingredients. The potential implications of the recent establishment of a substantial human threshold dose for ethyl methanesulfonate for the safety assessment of alkyl sulfonates in general are also discussed. Key findings The formation of alkyl sulfonates requires highly acidic conditions, possibly combined with long reaction times and/or elevated temperatures, to generate significant amounts, and these conditions are most unlikely to be present in the synthesis of active pharmaceutical ingredient sulfonate salts. It is possible to design salt formation conditions, using a short-chain alcohol as solvent, to manufacture sulfonate salts that are essentially free of alkyl sulfonate impurities. Processes using non-acidic conditions such as ethanol recrystallization or wet granulation should not raise any concerns of alkyl sulfonate formation. Summary An understanding of the mechanism of formation of alkyl sulfonates is critical in order to avoid restricting or over-controlling sulfonic acid salts, which have many technical advantages as pharmaceutical counterions. Recent regulatory acceptance of a human threshold limit dose of 2 mg/kg per day for ethyl methanesulfonate, indicating that its toxicological risks have previously been considerably overestimated, could signal the beginning of the end over safety concerns on alkyl sulfonate residues, thus removing a major constraint from the exploitation of sulfonic acid counterions. [source]

Economic costs of cataract surgery using a rigid and a foldable intraocular lens,

OPHTHALMIC AND PHYSIOLOGICAL OPTICS, Issue 4 2001
Asfa J. Afsar
Summary Optimal delivery of healthcare requires consideration of various costs. A foldable intraocular lens (IOL) is more expensive than an equivalent rigid IOL. However, surgical and post-operative costs may make a foldable IOL economically preferable. We compared the economic costs of cataract surgery plus implantation of a foldable IOL with implantation of a rigid IOL. Prospective audit of the clinical records of 82 pseudophakes; 39 implanted with a rigid IOL and 43 implanted with a foldable IOL by one surgeon. Average follow-up periods were 25±7 months and 23±5 months respectively. There was no difference between the two groups for the follow-up period (P=0.55), number of post-operative complications (P=0.25) or cost of post-operative visits (P=0.83). The cost of single-use theatre equipment was greater for the rigid-IOL group (P=0.0001). The total identified cost per patient was greater for the foldable-IOL group (P=0.0001). Despite possible technical advantages, implantation of the foldable IOL did not provide an economic benefit, either in the initial cost or in the costs of post-operative care. Over the 2-year period, implanting with the rigid IOL cost, on average, £57 less per patient. Despite this economic difference, a cost-benefit analysis is required, since other factors may be more important. [source]

Fibonacci grids: A novel approach to global modelling

THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 619 2006
Richard Swinbank
Abstract Recent years have seen a resurgence of interest in a variety of non-standard computational grids for global numerical prediction. The motivation has been to reduce problems associated with the converging meridians and the polar singularities of conventional regular latitude,longitude grids. A further impetus has come from the adoption of massively parallel computers, for which it is necessary to distribute work equitably across the processors; this is more practicable for some non-standard grids. Desirable attributes of a grid for high-order spatial finite differencing are: (i) geometrical regularity; (ii) a homogeneous and approximately isotropic spatial resolution; (iii) a low proportion of the grid points where the numerical procedures require special customization (such as near coordinate singularities or grid edges); (iv) ease of parallelization. One family of grid arrangements which, to our knowledge, has never before been applied to numerical weather prediction, but which appears to offer several technical advantages, are what we shall refer to as ,Fibonacci grids'. These grids possess virtually uniform and isotropic resolution, with an equal area for each grid point. There are only two compact singular regions on a sphere that require customized numerics. We demonstrate the practicality of this type of grid in shallow-water simulations, and discuss the prospects for efficiently using these frameworks in three-dimensional weather prediction or climate models. © Crown copyright, 2006. Royal Meteorological Society [source]

Composite bows at ed-Dur (Umm al-Qaiwain, U.A.E.)

ARABIAN ARCHAEOLOGY AND EPIGRAPHY, Issue 2 2005
An De Waele
This article discusses seven bone fragments excavated during the second Belgian archaeological campaign at ed-Dur (tomb G.3831, area N). Rather than weaving implements, these objects are identified as the reinforcing bone laths of composite bows. Information on the composite bow in general,origins, structural composition and technical advantages,will be given. Additionally, the question of which types of composite bows could have been present at ed-Dur and what role these weapons could have played at the site are discussed. [source]

Magnification devices for endodontic therapy

Q- und R-Matten aus Kunststoff für Bewehrungsaufgaben in der Geotechnik

BAUTECHNIK, Issue 9 2004
Georg Heerten Dr.-Ing.
Wachsende Güterströme und Warenverkehre im Zentrum eines wachsenden Europas und zunehmender Warenaustausch als Folge der Globalisierung der Weltwirtschaft stellen erhebliche Anforderungen an den Erhalt und Ausbau leistungsfähiger Infrastruktursysteme (Straße, Schiene, Wasserstraße). Nachhaltigkeitskonzepte bei der Bautätigkeit und Finanzierungsprobleme der öffentlichen Auftraggeber sind aktuelle Randbedingungen, denen mit Geokunststoff-Bauweisen optimal Rechnung getragen werden kann. Es können neben den technischen auch die ökonomischen und ökologischen Vorteile , Baukosten sparen, Baustoffressourcen schonen , parallel genutzt werden. Eine Stützwand als "Bewehrte-Erde-Konstruktion" kann ganz erheblich kostengünstiger als eine Stahlbeton-Stützmauer hergestellt werden. Die Ertüchtigung von wenig tragfähigen Böden mit flächig angeordneten Bewehrungslagen und/oder pfahlartigen geokunststoffummantelten Bodensäulen vermeidet umfangreichen Bodenaustausch, spart Kosten, verhindert umfangreichen Transport von Bodenmassen mit LKWs. Hierdurch werden knappe Baustoffressourcen wie Sand und Kies geschont sowie eine z. T. erhebliche Entlastung örtlicher Verkehrswege bewirkt. Q and R mats made of synthetics for reinforcement functions in the field of geotechnics. An increasing flow of goods in a growing central Europe, resulting from the globalisation of the world economy, makes high demands on the maintenance and development of an efficient infrastructure (road, railway, waterway). Sustainability concepts for the construction activities and funding problems of the contracting authorities are current boundary conditions which can be accommodated optimally with geosynthetic construction methods. At the same time, besides the technical advantages, the economical and ecological advantages can be used too , saving of construction costs and taking care of building materials resources. A retaining wall as "Reinforced-Earth-Structure" can be constructed at much lower cost than a retaining wall made of reinforced concrete. The improvement of subsoils with low bearing capacity, by using reinforcing layers in the area and/or soil columns similar to piles wrapped with geosynthetics, avoids a considerable exchange of soil, saves costs and avoids substantial soil transports by trucks. Thus, care is taken on rare building materials resources like sand and gravel and the traffic routes are partly released to a high extent. [source]