bluuebunny/crossref_metadata_2025 huggingface dataset:
Water quality management of aquifer recharge using advanced tools
Authors: Lazarova Valentina , Emsellem Yves , Paille Julie , Glucina Karl , Gislette Philippe
Published: September 2011

Managed aquifer recharge (MAR) with recycled water or other alternative resources is one of the most rapidly growing techniques that is viewed as a necessity in water-short areas. In order to better control health and environmental effects of MAR, this paper presents two case studies demonstrating how to improve water quality, enable reliable tracing of injected water and better control and manage MAR operation in the case of indirect and direct aquifer recharge. Two water quality management strategies are illustrated on two full-scale case studies, including the results of the combination of non conventional and advanced technologies for water quality improvement, comprehensive sampling and monitoring programs including emerging pollutants, tracer studies using boron isotopes and integrative aquifer 3D GIS hydraulic and hydrodispersive modelling.
Treatment of wastewater from a school in a decentralized filtration system by percolation over organic packing media
Authors: Garzón-Zúñiga M. A. , Buelna G.
Published: September 2011

Based on results obtained in the laboratory a WWTP composed of a septic tank and an aerated percolating filter packed with organic media was built for a school. The system can treat 18 m3 d−1 and was operated with a hydraulic loading rate of 0.078 (m3 m−2 d−1). For 360 days different operational conditions including start-up; stabilization; operation with aeration and non aeration; effect of rainy season, breaks from activities due to holidays and restart; were monitored and described in the article. Once stabilized, the system was able to remove, without the need for mechanical aeration, 97% of BOD5, 71% of COD, 93% of TKN, 11% of PO4−-P, 95% of TSS, 96% of VSS, in addition to having a removal efficiency of 4 log units of Faecal Coliforms (FC) and 100% helminthes eggs (HE). With this quality, the treated wastewater can be chlorinated and reused to irrigate green areas and/or in toilets. Although sanitary wastewater has a high concentration of Total-N (250 mg L−1) and a C/N ratio of less than 1, the system removed 65% of Total-N. Finally it was observed that after non activity periods, there was neither system failure nor the need to re-stabilize the system.
On the use of non-negative matrix factorisation to characterise wastewater from dairy processing plants
Authors: Sutherland-Stacey L. , Dexter R.
Published: September 2011

A portable field spectrometer was used to record the time-resolved ultraviolet/visible (UV/Vis) spectrum of the effluent stream at two different dairy processing plants (a Drier Plant and Cheese Factory). The spectra exhibited significant variability. As an alternative to the partial least squares regression methods usually used in the online UV/Vis field a non-negative matrix factorisation technique was employed to compress the spectral data. One of the extracted basis vectors had a physical shape associated with protein absorption. The weightings associated with the basis vector explained 80% of the variability in protein concentration as measured with traditional grab sampling techniques (increasing to 94% with a further three vectors), allowing the spectrometer to be retrospectively calibrated to continuously measure protein.
Exposure to dust, endotoxin and airborne microorganisms in wastewater sludge thermal drying units
Authors: Schlosser O. , Huyard A. , Catalán V.
Published: September 2011

The objective of this study was to assess workers' exposure to bioaerosols in sludge drying units. Simultaneous collection of inhalable dust and airborne biological agents was carried out using rotating cup samplers (CIP 10, Arelco). Sixteen stationary and 30 personal measurements were performed in three drying plants, during summer and winter. Microbial content of air was characterized by high amounts of Gram-negative bacteria, endotoxin, and thermophilic actinomycetes. High differences between exposure levels were observed with regard to workplaces and tasks. Dryers and conveyors in operation were closed, and the monitoring task in the dryer room was associated with low levels of personal exposure, close to background levels. Conversely, cleaning and maintenance of the dryer and conveyors required the equipment to be opened, giving significantly higher task-based personal exposure levels. The fall of dried sludge into indoor containers resulted in high emission and spreading of dust. Mean personal exposure levels to fungi were moderate or low for all tasks. Based on the results of this study, appropriate means of operational control and personal protection are being developed and implemented on sites.
Noble metal modified titania catalysts in the degradation of Reactive Black 5: a kinetic approach
Authors: Valentine Rupa A. , Vaithiyanathan R. , Sivakumar T.
Published: September 2011

The photocatalytic degradation of Reactive Black 5 (RB 5), a di-azo dye was investigated over M/TiO2 (M = Ag, Au and Pt) photocatalysts irradiated with UV and visible light. TiO2 was prepared by sol–gel technique (Syn-TiO2). Photodeposition of metal salt precursors over Syn-TiO2 was carried out so as to obtain 1 wt% of M/TiO2 catalysts. The photodecolourization and photodegradation reactions were also compared with commercial TiO2 (Degussa P25) catalyst. Kinetic studies for the decolourization of RB 5 showed that it followed pseudo first order. Recycling of catalysts was performed to check the economic feasibility of the photocatalytic process. In order to check the applicability of M/TiO2 catalyst in the treatment of industrial effluent, real textile effluent was collected from an industry and subjected to photodegradation and the results are presented. Enhanced activity of M/TiO2 catalyst under visible light irradiation highlights its importance in the field of photocatalysis.
Treatment performance and microbial characteristics in two-stage membrane bioreactor applied to partially stabilized leachate
Authors: Chiemchaisri C. , Chiemchaisri W. , Nindee P. , Chang C. Y. , Yamamoto K.
Published: September 2011

A two-stage membrane bioreactor system was applied to the treatment of partially stabilized leachate from solid waste landfill in Thailand. In the system, an anoxic tank with incline tube for biomass separation from re-circulated sludge is followed by a second-stage aerobic tank in which a direct submerged hollow-fiber membrane module is used for solid–liquid separation. During steady operation of 200 days, BOD, COD, NH3 and TKN removals were found to be 99.6, 68, 89 and 86% respectively. Determination of nitrogen transforming bacteria by fluorescent in-situ hybridization technique revealed a slightly higher percentage of nitrifying bacteria in the aerobic tank and a higher percentage of denitrifying bacteria in the anoxic tank respectively. Anammox-like bacteria were also detected at relatively high percentage.
Effect of membrane characteristics on the performance of membrane bioreactors for oily wastewater treatment
Authors: Mafirad S. , Mehrnia M. R. , Sarrafzadeh M. H.
Published: September 2011

Influence of membrane material and pore size on the performance of a submerged membrane bioreactor (sMBR) for oily wastewater treatment was investigated. The sMBR had a working volume of about 19 L with flat sheet modules at the same hydrodynamic conditions. Five types of micro- and ultra-polymeric membranes containing cellulose acetate (CA), cellulose nitrate (CN), polyamide (PA), polyvinylidene difluoride (PVDF) and polyethersulfone (PES) were used and their filtration performance in terms of permeability, permeate quality and fouling intensity were evaluated. Characterization of the membranes was done by performing some analysis such as pore size distribution; contact angle and scanning electronic microscopy (SEM) microphotograph on all membranes. The quality of permeates from each membrane was identified by measuring chemical oxygen demand (COD). The results showed more irreversible fouling intensity for membranes with larger pore size which can be due to more permeation of bioparticles and colloids inside the pores. Membrane characteristics have a major role in the preliminary time of the filtration before cake layer formation so that the PA with the highest hydrophilicity had the lowest permeability decline by fouling in this period. Also, the PVDF and PES membranes had better performance according to better permeate quality in the preliminary time of the filtration related to smaller pore size and also their better fouling resistance and chemical stability properties. However, all membranes resulted in the same permeability and permeate quality after cake layer formation. An overall efficiency of about 95% in COD removal was obtained for oily wastewater treatment by the membranes used in this study.
A Modified Maximum Contrast Method for Unequal Sample Sizes in Pharmacogenomic Studies
Authors: Nagashima Kengo , Sato Yasunori , Hamada Chikuma
Published: September 2011

In pharmacogenomic studies, biomedical researchers commonly analyze the association between genotype and biological response by using the Kruskal-Wallis test or one-way analysis of variance (ANOVA) after logarithmic transformation of the obtained data. However, because these methods detect unexpected biological response patterns, the power for detecting the expected pattern is reduced. Previously, we proposed a combination of the maximum contrast method and the permuted modified maximum contrast method for unequal sample size in pharmacogenomic studies. However, we noted that the distribution of the permuted modified maximum contrast statistic depends on nuisance parameter σ2, which is the population variance. In this paper, we propose a modified maximum contrast method with a statistic that does not depend on the nuisance parameter. Furthermore, we compare the performance of these methods via simulation studies. The simulation results showed that the modified maximum contrast method gave the lowest false-positive rate; therefore, this method is powerful for detecting the true response patterns in some conditions. Further, it is faster and more accurate than the permuted modified maximum contrast method. On the basis of these results, we suggest a rule of thumb to select the appropriate method in a given situation.
Currarino Syndroma, initially misdiagnosed and treated like megacolon congenitum
Authors: Djordjevic Ivona , Jovanovic Danica , Grujic Blagoje
Published: September 2011

Currarino syndrome was first described as a triad by Guido Currarino, an American radiologist in 1981. It is an autosomal dominant hereditary disease known by the triad of anorectal stenosis, anterior sacral defect, and a presacral mass that is most often an anterior sacral meningocele.

We represent a 3 year boy with refractory constipation from birth, which had been wrongly diagnosed and treated as Hirschsprung’s disease since early childhood. The patient underwent urgent colostomy because of water intoxication due to bowel irrigation, and following investigations (CT, MRI) revealed anorectal anomaly and presacral mass compatible with Curarrino’s syndrome.

Definitive operation was done with perineal approach, posterior sagittal anorectoplasty, with interval colostomy closure 2 months after perineal operation. An uncomplicated postoperative recovery ensued. The patient’s bowel habits successfully returned to normal soon after the operation. A multidisciplinary diagnostic and therapeutic protocol is presented. Main points are rectal examination, sacrum x-Ray, molecular genetic diagnosis, radiologic evaluation of every member of Currarino syndrome families, CT scan, magnetic resonance (MR) evaluation of patient spine and pelvis and suction rectal biopsies. If the mass is a meningocele, colostomy and neurosurgical exploration should precede anoplasty due to the risk of meningitis.
[Ni(1,10-phenanthroline)2(H2O)2](NO3)2: A Simple Coordination Complex with a Remarkably Complicated Structure that Simplifies on Heating
Authors: Prior Timothy J. , Rujiwatra Apinpus , Chimupala Yothin
Published: September 2011

Despite the simple chemical formula, [Ni(1,10-phenanthroline)2(H2O)2](NO3)2, crystallizes with a remarkably complicated 3-D hydrogen bonding supramolecular assembly. The title compound crystallizes in the monoclinic space group P21/c, with an unusually long b axis and a large cell volume. A huge asymmetric unit has been identified, containing six discrete [Ni(1,10-phen)2(H2O)2]2+ cations and twelve nitrate anions. Detailed analyses of the crystal structure and O-H×××O and C-H×××O hydrogen bonding interactions are reported and discussed. In this way the anion-directed assembly of the 3-D structure is illustrated. The thermal and spectroscopic properties of the compound are described. Upon heating to 308 K, the crystal undergoes a phase change to a much simpler structure with a single [Ni(1,10-phen)2(H2O)2]2+ cation within the asymmetric unit and unit cell volume one sixth of that at low temperature. Although the crystal decomposed during data collection, it was possible to establish the molecular packing in the high temperature form and relate it to that at low temperature.
The Paradox of Nutrition-Related Diseases in the Arab Countries: The Need for Action
Authors: Musaiger Abdulrahman O. , Hassan Abdelmonem S. , Obeid Omar
Published: September 2011

The aim of this review was to highlight the current situation of nutrition-related diseases in the Arab countries, and factors associated with prevalence of these diseases. PubMed and Google Scholar were searched for data relating to such nutrition-related diseases published between January 1990 and May 2011. The picture of nutritional status in the Arab countries has changed drastically over the past 30 years as a result of changes in the social and economic situation. Two contrasting nutrition-related diseases exist, those associated with inadequate intake of nutrients and unhealthy dietary habits such as growth retardation among young children and micronutrient deficiencies; and those associated with changes in lifestyle such as cardiovascular disease, cancer, osteoporosis, diabetes and obesity (diet-related non-communicable diseases). Factors contributing to nutritional problems vary from country to country, depending on socio-economic status. In general, unsound dietary habits, poor sanitation, poverty, ignorance and lack of access to safe water and health services are mainly responsible for under-nutrition. Changes in lifestyle and dietary habits as well as inactivity are associated with the occurrence of diet-related non-communicable diseases. Programs to prevent and control nutrition-related diseases are insufficient and ineffective, due mainly to a focus on curative care at the expense of preventive health care services, lack of epidemiological studies, lack of nutritional surveillance, inadequate nutrition information and lack of assessment of the cost-effectiveness of nutrition intervention programs.
Liquid Encapsulation in Parylene Microstructures Using Integrated Annular-Plate Stiction Valves
Authors: Gutierrez Christian A. , Meng Ellis
Published: September 2011

We report the design, fabrication and characterization of micromachined Parylene structures for self-sealing liquid encapsulation applications. Automatic sealing is enabled through the use of an integrated annular-plate stiction valve which greatly reduces device footprint over in-plane configurations. We achieve automatic wafer-level liquid entrapment without using adhesives or processing at elevated pressures or temperatures. The ability to track changes to the internal liquid volume through the use of electrochemical impedance measurements is also presented.
Synthesis and Chemical Characterisation of Some New Diheteroaryl Thienothiophene Derivatives
Authors: Mabkhot Yahia Nasser , Al-Majid Abdullah Mohammad , Alamary Abdullah S.
Published: September 2011

Treatment of 1-(5-acetyl-3,4-dimethythieno[2,3-b]thiophene-2yl)ethanone (1) with dimethylformamide dimethyl acetal afforded enaminone derivative 2, which reacted with amino derivatives to give the corresponding bis-pyrimidine, bis-pyrazole, bis-triazolo-pyrimidine and bis-benzoimidazopyrimidine derivatives.
Real-Time Remote Monitoring of Temperature and Humidity Within a Proton Exchange Membrane Fuel Cell Using Flexible Sensors
Authors: Kuo Long-Sheng , Huang Hao-Hsiu , Yang Cheng-Hao , Chen Ping-Hei
Published: September 2011

This study developed portable, non-invasive flexible humidity and temperature microsensors and an in situ wireless sensing system for a proton exchange membrane fuel cell (PEMFC). The system integrated three parts: a flexible capacitive humidity microsensor, a flexible resistive temperature microsensor, and a radio frequency (RF) module for signal transmission. The results show that the capacitive humidity microsensor has a high sensitivity of 0.83 pF%RH−1 and the resistive temperature microsensor also exhibits a high sensitivity of 2.94 × 10−3 °C−1. The established RF module transmits the signals from the two microsensors. The transmission distance can reach 4 m and the response time is less than 0.25 s. The performance measurements demonstrate that the maximum power density of the fuel cell with and without these microsensors are 14.76 mW·cm−2 and 15.90 mW·cm−2, with only 7.17% power loss.
Remote (250 km) Fiber Bragg Grating Multiplexing System
Authors: Fernandez-Vallejo Montserrat , Rota-Rodrigo Sergio , Lopez-Amo Manuel
Published: September 2011

We propose and demonstrate two ultra-long range fiber Bragg grating (FBG) sensor interrogation systems. In the first approach four FBGs are located 200 km from the monitoring station and a signal to noise ratio of 20 dB is obtained. The second improved version is able to detect the four multiplexed FBGs placed 250 km away, offering a signal to noise ratio of 6–8 dB. Consequently, this last system represents the longest range FBG sensor system reported so far that includes fiber sensor multiplexing capability. Both simple systems are based on a wavelength swept laser to scan the reflection spectra of the FBGs, and they are composed by two identical-lengths optical paths: the first one intended to launch the amplified laser signal by means of Raman amplification and the other one is employed to guide the reflection signal to the reception system.
Antiviral Treatment of Calves Persistently Infected with Bovine Viral Diarrhoea Virus
Authors: Newcomer Benjamin W , Marley M Shonda , Galik Patricia K , Walz Paul H , Zhang Yijing , Riddell Kay P , Dykstra Christine C , Boykin David W , Kumar Arvind , Cruz-Espindola Crisanta , Boothe Dawn M , Joiner Kellye S , Givens M Daniel
Published: September 2011

Background:

Animals persistently infected (PI) with bovine viral diarrhoea virus (BVDV) are a key source of viral propagation within and among herds. Currently, no specific therapy exists to treat PI animals. The purpose of this research was to initiate evaluation of the pharmacokinetic and safety data of a novel antiviral agent in BVDV-free calves and to assess the antiviral efficacy of the same agent in PI calves.

Methods:

One BVDV-free calf was treated with 2-(2-benzimidazolyl)-5-[4-(2-imidazolino)phenyl]furan dihydrochloride (DB772) once at a dose of 1.6 mg/kg intravenously and one BVDV-free calf was treated three times a day for 6 days at 9.5 mg/kg intravenously. Subsequently, four PI calves were treated intravenously with 12 mg/kg DB772 three times a day for 6 days and two PI control calves were treated with an equivalent volume of diluent only.

Results:

Prior to antiviral treatment, the virus isolated from each calf was susceptible to DB772 in vitro. The antiviral treatment effectively inhibited virus for 14 days in one calf and at least 3 days in three calves. Subsequent virus isolated from the three calves was resistant to DB772 in vitro. No adverse effects of DB772 administration were detected.

Conclusions:

Results demonstrate that DB772 administration is safe and exhibits antiviral properties in PI calves while facilitating the rapid development of viral resistance to this novel therapeutic agent.
La persistance de l'effet patrimoine lors des élections présidentielles françaises
Authors: Foucault Martial , Nadeau Richard , Lewis-Beck Michael S.
Published: September 2011

Résumé Dans un ouvrage novateur, France de gauche, vote à droite (1981), Jacques Capdevielle et al . ont mis à jour il y a une trentaine d’années l’existence d’un « effet patrimoine » expliquant de façon significative le comportement électoral en France. Malgré la portée de ce résultat, l’étude de cette question a reçu moins d’attention par la suite. La mesure du patrimoine a occupé de moins en moins de place dans les enquêtes électorales françaises, notamment au moment des élections présidentielles de 2007. Nous démontrons dans ce texte que l’effet patrimoine est toujours aussi pertinent aujourd’hui pour expliquer le comportement électoral en France. En proposant un modèle général inspiré des travaux sur l’aversion au risque, nous montrons comment le patrimoine risqué se révèle être un puissant prédicteur du vote à droite en France sur la période 1988-2007. Ce constat montre l’intérêt de renouer avec un concept novateur de la science politique française.
Les groupes d'intérêt vus du local
Authors: Pollard Julie
Published: September 2011

Résumé L’objectif de cet article est de montrer que la prise en compte de niveaux infranationaux peut conduire à reconsidérer l’analyse de certains groupes d’intérêt dans des secteurs d’action publique. Le texte s’appuie empiriquement sur le cas des promoteurs immobiliers dans les politiques du logement en France. Il met en avant les difficultés et limites des mobilisations collectives de ces acteurs au plan national. Les promoteurs immobiliers sont cependant des acteurs déterminants dans la régulation du secteur du logement, du fait de leurs mobilisations – le plus souvent individuelles – dans les territoires infranationaux. Leur influence passe en particulier par deux vecteurs au plan local : leur participation à la mise en œuvre de politiques, en premier lieu fiscales, décidées par le gouvernement central ; et leurs mobilisations tournées vers les acteurs politiques locaux, détenteurs du droit de délivrer les permis de construire.
Nouvelles dynamiques de savoirs et permanence des rapports de pouvoir
Authors: Henry Emmanuel
Published: September 2011

Résumé Cet article analyse les transformations contemporaines de la production de connaissances et d’expertise en santé au travail en replaçant ces évolutions avec les spécificités et les évolutions récentes de ce secteur d’intervention publique. Après avoir montré comment les changements des politiques de santé publique contraignent à un certain nombre de transformations dans le domaine de la santé au travail, notamment en obligeant à créer de nouvelles instances d’expertises, cet article analyse comment l’expertise des risques professionnels s’institutionnalise et les effets induits sur les modalités de la prise de décision dans ce domaine. Il montre qu’au-delà de bouleversements importants, les rapports de pouvoir qui caractérisent ce domaine d’intervention restent relativement stables. Au delà du cas de la santé au travail, cet article invite à reposer les questions de la production de connaissances et de l’expertise en les mettant en perspective avec les rapports de force qui structurent un secteur d’intervention publique.
La philosophie transcendantale de Fichte ou « les limites de ma conscience comme limites de mon monde »
Authors: Breazeale Dan , Thomas-Fogiel Isabelle
Published: September 2011

Peu de philosophes ont autant insisté sur la différence entre la lettre et l’esprit d’une philosophie que Fichte. Breazeale prend Fichte au mot concernant cette distinction et tente de reconstituer ce qu’il appelle l’esprit de la philosophie d’Iéna, soit la première version de la philosophie que Fichte construisit entre 1793 et 1799. L’auteur montre combien Fichte est loin de la caricature de l’idéalisme débridé, interprétation qui prévalut chez les commentateurs classiques comme dans une certaine philosophie analytique. Il montre aussi comment une vulgate plus contemporaine qui tend à surinvestir l’aspect religieux (en valorisant notamment ce qu’on appelle la dernière philosophie) manque le sens et l’esprit de la philosophie d’Iéna et renoue ainsi avec l’interprétation traditionnelle d’un Fichte dogmatique et métaphysicien.
Loi restrictive et loi productive dans l'éthique fichtéenne
Authors: Piché Claude
Published: September 2011

« Nous devons tous agir de la même manière. » Cette phrase percutante, pour ne pas dire provocante, intervient dans un passage du § 18 du Système de l’éthique où Fichte expose le principe de la morale. C’est dire que cette affirmation à propos de l’« uniformité de l’agir » traduit à sa manière la teneur de la conception fichtéenne de la loi morale. La question qui se pose alors est la suivante : comment faut-il comprendre cette exigence d’uniformisation de l’agir de la part de Fichte ? Pour y répondre, il convient selon nous de porter attention à la manière dont ce dernier se démarque de Kant en ce qui a trait à l’interprétation de la loi morale.
Théorie de l'éthique et de l'éthique appliquée chez Fichte : Sittenlehre ou Metaphysik der Sitten
Authors: Nuzzo Angelica , Rockmore T.
Published: September 2011

En étudiant la Sittenlehre (1798) comme réponse de Fichte à Kant, l’auteure se concentre sur l’applicabilité et l’application de principes moraux. Fichte, qui insiste particulièrement sur le problème de l’application de l’éthique, ouvre un chemin pour entreprendre une révision de la théorie kantienne radicale et ultimement incompatible avec les prémisses transcendantales du kantisme.
Comment Fichte rompt avec la représentation
Authors: Wilson Eric , Rockmore T.
Published: September 2011

L’auteur montre comment très tôt, c’est-à-dire dès 1793 et la « Recension d’Énésidème », Fichte se détache de la conception moderne du représentationalisme en épistémologie comme en sémantique. L’auteur analyse à ce titre la Déduction de la représentation de la WL de 1794. Si Kant reste prisonnier de la conception représentationaliste, Fichte s’engage dans une voie autre en effectuant ici une rupture décisive avec la tradition.
Acromioclavicular Joint Pain in Patients With Adhesive Capsulitis: A Prospective Outcome Study
Authors: Anakwenze Oke A. , Hsu Jason E. , Kim Jae S. , Abboud Joseph A.
Published: September 2011

Diagnosis of adhesive capsulitis is a clinical diagnosis based on history and physical examination. Afflicted patients exhibit active and passive loss of motion in all planes and a positive capsular stretch sign. The effect of adhesive capsulitis on acromioclavicular biomechanics leading to tenderness has not been documented in the literature. This study reports on the incidence of acromioclavicular tenderness in the presence of adhesive capsulitis. Furthermore, we note the natural history of such acromioclavicular joint pain in relation to that of adhesive capsulitis.

Over a 2-year period (2005–2007), 84 patients undergoing initial evaluation for adhesive capsulitis were prospectively examined with the use of validated outcome measures and physical examination. Acromioclavicular joint tenderness results were compared and analyzed on initial evaluation and final follow-up of at least 1 year. Forty-eight patients (57%) with adhesive capsulitis had acromioclavicular joint pain on examination. At final follow-up, as range of motion improved, a significant increase in American Shoulder and Elbow Surgeons/Penn shoulder score and decrease in number of patients with acromioclavicular pain was noted with only 6 patients with residual pain (
P
<.05).

In the presence of adhesive capsulitis, there is not only compensatory scapulothoracic motion but also acromioclavicular motion. This often results in transient symptoms at the acromioclavicular joint, which abate as the frozen shoulder resolves and glenohumeral motion improves. This is important to recognize to avoid unnecessary invasive treatment of the acromioclavicular joint when the patient presents with adhesive capsulitis.
Is Repetitive Intraoperative Splash Basin Use a Source of Bacterial Contamination in Total Joint Replacement?
Authors: Glait Sergio A. , Schwarzkopf Ran , Gould Steven , Bosco Joseph , Slover James
Published: September 2011

Splash basins are used in arthroplasty cases to wash instruments. Several studies in the literature have shown these basins being a potential source of bacterial infection. This study assesses the risk of contamination of intraoperative splash basins used to wash and store instruments. A total of 46 random clean primary arthroplasty cases (32 hips, 13 knees, and 1 unicondylar knee) were studied by taking cultures of sterile splash basins as soon as they are opened (controls) and again at wound closure after instruments and debris have come into contact with the sterile water. All cultures were taken with sterile culture swabs and sent to the laboratory for aerobic, anaerobic, and fungal culture. Outcome measured was any positive culture. A total of 92 cultures from 46 cases were tested. Only 1 (2.17%) control culture, which grew
Streptococcus viridans,
was positive for bacterial growth. One of 46 samples (2.17%) taken at wound closure was positive for coagulase-negative
Staphylococcus
. Mean time between basin opening and wound closure was 180±45 minutes. For the 1 infected sample taken at the conclusion of the case, it was 240 minutes. Previous studies show contamination rates as high as 74% for splash basins used intraoperatively. Our study contradicts the belief that splash basins are a high source of infection, with only 2.17% of basins showing contamination. Splash basins can be a potential source of contamination, but the risk is not as high as previously cited in the orthopedic literature.
Experimental Study on Phase-contrast Imaging With Synchrotron Hard X-ray for Repairing Osteonecrosis of the Femoral Head
Authors: Sun Wei , Li Zi-rong , Yang Yu-Run , Shi Zhen-cai , Wang Bailiang , Liu Bingli , Shi Shaohui
Published: September 2011

Synchrotron radiation light is 1 of 4 artificial light sources, the others being electric light, X-ray, and laser. Phase-contrast imaging with hard X-ray has achieved wide application in many scientific fields, such as biomedicine and material science. This article compares the effectiveness of nanohydroxyapatite/collagen (nHAC) and autologous mesenchymal stem cell for the repair of defects in a rabbit model with osteonecrosis of the femoral head under the monitoring of phase-contrast imaging with synchrotron hard X-ray. We established models of bilateral osteonecrosis of the femoral head defect using New Zealand rabbits and divided them into 3 groups. Imaging techniques such as phase-contrast imaging and diffraction enhanced imaging with synchrotron hard X-ray were applied to assess the degradation and repair process of nHAC and mesenchymal stem cell at 4, 8, and 12 weeks postoperatively. We found phase-contrast imaging with synchrotron hard X-ray displayed the reparative process of the bone defect, degradation of nHAC, and osteocyte substitution. There were significant differences in the repair of the bone defect and osteogenesis in groups B and C compared with group A (control). Osteogenesis was more significant in group C. We provided experimental data for the development and application of synchrotron hard X-ray imaging techniques and concluded that phase-contrast microimaging with synchrotron hard X-ray displays the reparative process of bone tissue at a micro-level and plays an important role in the development of tissue engineering.
Long-term Effectiveness of Sorbie-QUESTOR Elbow Arthroplasty: Single Surgeon’s Series of 15 Years
Authors: Sorbie Charles , Saunders Gerald , Carson Patricia , Hopman Wilma M. , Olney Sandra J. , Sorbie Janet
Published: September 2011

With increasing usage of many types of total elbow replacements, there is a continuing need for clinical series that report survivorship, complications and revisions, and performance of single types of implants over extended time periods. The purpose of this study was to assess the long-term effectiveness of all implants of the Sorbie-QUESTOR (SQ) unlinked surface arthroplasty conducted by a single surgeon (C.S.) over 15 years at a single site, and to determine whether there were diagnostic group differences. Between 1995 and 2002, 51 S-Q prosthetic elbows were implanted into 44 patients. The patient groups were hemophilia, rheumatoid arthritis, and “other,” which included osteoarthritis, traumatic arthritis, psoriatic arthritis, and reactive arthritis. Annual evaluations included scores of pain, range of motion, and function. The most recent annual evaluation was included in the data set. Details of complications and revisions were recorded. The hemophiliac group had the best survival outcomes at 87.5%. Eighteen prostheses required revision or removal with all but 3 retained or replaced. Postoperatively, 73% rated their pain as ‘slight’ or ‘none’. The hemophilia and rheumatoid arthritis groups made very large total flexion/extension gains. The rheumatoid arthritis group made significant forearm motion gains. Average functional assessment gains were nearly 2 grades of 5 functional levels and were significant for all groups. The S-Q surface arthroplasty has demonstrated long-term effectiveness in patients with a variety of elbow joint pathologies showing reduction in pain, large gains in joint range and function, and good long-term survival.
Primary Total Joint Arthroplasty Performed in Operating Rooms Following Cases of Known Infection
Authors: Namdari Surena , Voleti Pramod B. , Baldwin Keith D. , Lee Gwo-Chin
Published: September 2011

No study has examined infection rates in “clean” cases following “dirty” cases. This study evaluated patients undergoing elective primary total joint arthroplasties performed in operating rooms following cases of known infection for development of postoperative infection. A retrospective review of all elective primary total joint arthroplasties performed over a 5-year period at our institution was conducted. Patients who underwent primary total joint arthroplasties that followed cases of known infection in the same operating room were examined (minimum follow-up of 1 year) to determine the occurrence of infection based on culture data and subsequent procedures. Thirty-nine total joint arthroplasties (27 total knee arthroplasties and 12 total hip arthroplasties) in 35 patients were performed following cases of known infection in the same operating room. Of these patients, 1 (2.6%) developed a periprosthetic joint infection. The infecting organism (
Propionibacterium acnes
) was the same as that isolated from the preceding “dirty” case. Further investigation is necessary to determine whether performing primary total joint arthroplasties immediately following “dirty” cases increases risk of infection.
Metal-on-Metal Surface Replacement: A Triumph of Hope Over Reason: Affirms
Authors: Cuckler John M.
Published: September 2011

Metal-on-metal hip resurfacing offers some potential for total hip arthroplasty (THA) in the young patient. However, short- and intermediate-term results of the currently available implants have failed to demonstrate advantage over conventional THA. The risks of femoral neck fracture or avascular necrosis have been disappointing early limitations of the procedure. The Australian Joint Registry reports a 5-year revision rate of all hip resurfacings of 3.8%, compared with conventional THAs at 2.8%, and a 9-year cumulative revision rate of 7.2% for hip resurfacings. Recent reports of femoral neck erosion and pseudotumors associated with resurfacing have raised concern about the survivorship of the procedure in some patients. Recently, the British Medicines and Healthcare Product Regulatory Agency issued an alert over adverse reactions associated with metal-on-metal THAs, with particular concern expressed about hip resurfacings.

Acetabular bone stock may not be conserved when large-diameter femoral head components are used, depending on the surgical technique and implant design. In hip resurfacing, the minimum diameter femoral component avoids notching of the femoral neck; thus, larger diameter acetabular components may be necessary to accommodate the femoral component. Hip resurfacing is contraindicated in cases of avascular necrosis of the femoral head, especially with cysts >1 cm in diameter, with severe slipped capital femoral epiphysis, and in some posttraumatic arthroses; furthermore, the biomechanics of the resurfaced hip appear to be less reliably restored than with conventional THA. The hypothesis that resurfacing is a more conservative procedure than conventional THA remains unproven at this time. Given the documented intermediate failure rates of resurfacing, metal-on-polyethylene is the more successful implant choice.
Metal-on-Metal Surface Replacement: A Triumph of Hope Over Reason: Opposes
Authors: Su Edwin P. , Su Sherwin L.
Published: September 2011

Hip resurfacing has been performed for over a decade but still raises controversy as an alternative to traditional total hip arthroplasty (THA). Concerns exist about the potential complications of hip resurfacing, including femoral neck fracture and osteonecrosis of the femoral head. Recently, attention has been given to the metal-on-metal bearing of hip resurfacing with regard to production of metal ions, possible tissue necrosis, and rare instances of metal hypersensitivity. Given the success of the gold-standard THA, it is understandable why some surgeons believe metal-on-metal surface replacement to be “a triumph of hope over reason.” However, this article opposes that viewpoint, demonstrating that data exist to justify the practice of preserving bone in younger patients.

Hip resurfacing can maintain femoral bone without the expense of removing additional acetabular bone by using modern implants with incremental sizing. Furthermore, many of the problems cited with the bearing couple (such as excess metal production) have been due to poor implant designs, which have now been removed from the market. Finally, we now realize that the metal-on-metal articulation is more sensitive to malposition; thus, good surgical technique and experience can solve many of the problems that have been cited in the past. National registry results confirm that in a select population, hip resurfacing performs comparably to THA, while fulfilling the goal of bone preservation.
Stubby Stems: Good Things Come in Small Packages
Authors: Lombardi Adolph V. , Berend Keith R. , Ng Vincent Y.
Published: September 2011

Standard-length porous-coated tapered femoral stems perform exceedingly well in primary total hip arthroplasty (THA) at long-term follow-up. Nevertheless, there are multiple reasons to strongly consider the relatively new concept of short tapered stems. First, there is already a wide variation in the lengths of “standard” components and the ideal length is unknown. The goal of tapered stems is to load the proximal femur, and shortened stems accomplish this task. Second, while the distal extension may help prevent varus, unlike cemented stems, which are failure-prone with varus alignment, tapered designs are not. Additionally, elimination of the distal extension may reduce potential stress shielding. Third, short stems obviate problems with proximal-distal mismatch, excessive femoral bowing, diaphyseal deformities, and preexisting hardware. Fourth, implantation of smaller components requires less violation of bone and soft tissue, facilitating less invasive surgical approaches and favorable revision settings if necessary. Fifth, in comparison to hip resurfacing and other unconventional short-stem designs, tapered stems are familiar to most orthopedic surgeons and do not incur a steep learning curve. Finally, our early experience with this implant in 1750 THAs since 2006 has been excellent. In a series of >650 THA, compared to standard-length tapered stems, the short stem had equivalent clinical outcome scores, significantly fewer femoral fractures (12/389 [3.1%] vs 1/269 [0.4%]), and only 1 (1/269 [0.4%]) femoral revision (infection) at 2-year follow-up. Short stems represent the logical progression of a proven precedent in standard-length tapered stems.
Robotic Guidance in Total Hip Arthroplasty: The Shape of Things to Come
Authors: Dorr Lawrence D. , Jones Richard E. , Padgett Douglas E. , Pagnano Mark , Ranawat Amar S. , Trousdale Robert T.
Published: September 2011

Surgeons want to perform a perfect total hip arthroplasty (THA) with every operation. Human performance has limitations, especially when performing a mechanical operation in a biological environment. Recent suggested changes to improve outcomes have been large femoral heads and anterior incisions, but unfortunately, neither has resulted in any scientific data that change has been effected. The scientific data tell us that poor component positions and impingement are the source of increasing mechanical complications. Therefore, attempts have been made to improve the surgeon’s performance by precise quantitative knowledge in the operating room. Robotic-guided navigation provides numerical data for cup inclination plus anteversion and center of rotation; femoral leg length and offset; and combined anteversion of the cup and stem. The acetabular bone preparation is done with a reamer connected to a robotic arm, which prevents human error by the surgeon of reaming off line or too deep. This technology provides predictable and reproducible results.
The Posterior Approach in THR: Assuring Capsular Stability
Authors: Ranawat Chitranjan S. , Meftah Morteza , Potter Hollis G. , Ranawat Amar S.
Published: September 2011

Repair of the posterior capsule is advocated to reduce dislocation after total hip replacement (THR). To date, no predictable physical findings are reported in the literature to assess the capsular integrity and risk of hip dislocation after the posterior approach. The internal rotation test is performed at 4 to 6 weeks postoperatively with the hip and knee flexed at 90° while the patient is supine. The test is positive if a firm endpoint is felt with internal rotation of ≤15°.

Between January 2007 and January 2008, twenty-three patients who had magnetic resonance imaging (MRI) at a mean 1.8±0.7 years after posterior-approach THR were included in this study. Magnetic resonance images were reviewed by a blinded radiologist for the integrity of the posterior capsule and quadratus, the distance between the piriformis and conjoined tendon to bone, and the amount of piriformis obturator internus atrophy. Magnetic resonance imaging results in patients with positive internal rotation tests showed an intact posterior capsule and scarring of the tendons with no severe muscle atrophy. In patients with a negative internal rotation test, MRI showed incomplete healing of the tendons and severe muscle atrophy. Sensitivity and specificity of the internal rotation test for tendon/scar healing were 100% and 93%, respectively.

The internal rotation test is a simple, reproducible test that, if positive, has a high correlation with capsule/tendon healing.
Neutral Mechanical Alignment: A Requirement for Successful TKA: Opposes
Authors: Bellemans Johan
Published: September 2011

There is increasing evidence that for a number of patients, neutral alignment is not normal. Patients with so-called constitutional varus have been in varus alignment since the end of their growth. Restoring neutral alignment in these cases may not be the best option for these patients since it is abnormal to them.

We recently performed a number of observational studies to find out how patients develop constitutional varus, how these patients can be recognized, and which factors contribute. A cohort of 800 young patients was analyzed to determine the influence of activity level on growth and the development of lower-leg alignment. At the same time, 250 asymptomatic adults between 20 and 27 years were analyzed to determine the incidence of constitutional varus. The results showed that 32% of adult men and 17% of adult women had constitutional varus knees with a natural mechanical alignment ≥3° varus. Constitutional varus was associated with increased sports activity during growth and began to become apparent at the time of growth spurt.

Based on these data, we believe that an important fraction of the normal population has a natural alignment at the end of growth of ≥3° varus. This may be a consequence of Hueter-Volkmann’s law. Restoration of mechanical alignment to neutral in these cases therefore may not be desirable and in fact unnatural for them.
Results of Prospective, Randomized Clinical Trials Comparing Standard and High-flexion Posterior-stabilized TKA: A Focused Review
Authors: Hamilton William G. , Sritulanondha Supatra , Engh C. Anderson
Published: September 2011

High-flexion total knee arthroplasty (TKA) designs have been available for several years for patients desiring a greater postoperative flexion. We conducted a focused review on published results of prospective, randomized clinical trials that compared a standard posterior-stabilized TKA with a high-flexion posterior-stabilized TKA design. Follow-up ranged from 1 to 2.7 years. None of the articles included in the review showed a statistical difference between the standard and high-flexion designs in clinical flexion or range of motion. Mean postoperative flexion ranged from 106° to 130° for the standard design and 110° to 128° for the high-flexion design.

Based on currently available literature, high-flexion cruciate-substituting TKAs do not appear to provide increased flexion in the short term. The downsides of these designs, such as increased cost, increased bone resection, and early femoral loosening, need to be weighed against the potential long-term improvement in polyethylene wear due to increased conformity in high flexion. Continued follow-up to document these findings will be important.
Successful Outcomes of 25- and 23-Gauge Vitrectomies for Giant Retinal Tear Detachments
Authors: Kunikata Hiroshi , Abe Toshiaki , Nishida Kohji
Published: September 2011

BACKGROUND AND OBJECTIVE:

The authors examined the feasibility of performing 25- and 23-gauge micro-incision vitrectomy surgery (MIVS) for a giant retinal tear.

PATIENTS AND METHODS:

The medical records of 12 eyes of 11 patients with giant retinal tear who underwent MIVS using perfluorocarbon liquids were reviewed. All patients were observed for at least 6 months postoperatively.

RESULTS:

An intraoperative re-attachment was achieved in 12 eyes (100%) and 11 eyes (92%) remained attached without intraocular tamponade. Silicone oil was used in 9 of 12 eyes and removed 2 weeks after the initial vitrectomy except in one eye. The postoperative retinal complications included macular pucker in two eyes, subretinal perfluorocarbon liquid in two eyes, retinal folds in one eye, cystoid macular edema in one eye, and redetachment due to proliferative vitreoretinopathy in one eye.

CONCLUSION:

Although the study had a short follow-up period, primary MIVS appears to be safe and feasible for giant retinal tear surgery.