Imaging of progressive collapsing foot deformity with emphasis on the role of weightbearing cone beam CT.

The term progressive collapsing foot deformity (PCFD) is currently recommended as the replacement to adult-acquired flatfoot deformity and posterior tibial tendon dysfunction to better reflect its pathology, which consists of a complex three-dimensional deformity involving the foot and ankle. The new consensus has also provided a new classification that requires clinical and radiographic findings for patient stratification into each class. However, conventional radiographs are susceptible to errors resulting from the inadequate positioning of patients, incorrect angulation of the X-ray tube, and overlapping of bone structures. Weightbearing cone beam computed tomography (WBCBCT), which has greater diagnostic accuracy than conventional radiograph, is useful for evaluating progressive collapsing foot deformity to determine medial arch collapse, hindfoot alignment, peritalar subluxation, posterior subtalar joint valgus, intrinsic talus valgus, and lateral extra-articular bone impingement. The present review aimed to discuss the new recommendations for nomenclature, classification, and imaging evaluation of PCFD, with an illustrative and quantitative focus on the measurements used in conventional radiography and WBCBCT. The measurements presented here are important criteria for decision-making.

Effect of operating conditions on N2O production in an anammox sequencing batch reactor containing granular sludge.

Nitrous oxide (N2O) is one of the gases with the greatest impact in the atmosphere due to its persistence and significant contribution to the greenhouse effect. This study provides an insight into the dynamics of N2O production in wastewater nitrogen removal systems. A 10 L sequencing batch reactor containing enriched anammox biomass was subjected to different operational conditions, i.e., temperature, feed time, NO2 -/NH4 + ratio and the initial concentrations of NH4 + and NO2 -. Tests showed no significant differences in maximum N2O production when the system was operated with a shorter feed time and no increase in the operating temperature. A higher N2O production was observed when the initial NO2 -/NH4 + ratio increased from 1.3 to 1.7 and 1.9. The highest initial concentration of NO2 - was linked to an increase in residual N2O at the end of the batch cycle, probably due to heterotrophic denitrifying metabolism.

Yeast: the soul of beer's aroma--a review of flavour-active esters and higher alcohols produced by the brewing yeast.

Among the most important factors influencing beer quality is the presence of well-adjusted amounts of higher alcohols and esters. Thus, a heavy body of literature focuses on these substances and on the parameters influencing their production by the brewing yeast. Additionally, the complex metabolic pathways involved in their synthesis require special attention. More than a century of data, mainly in genetic and proteomic fields, has built up enough information to describe in detail each step in the pathway for the synthesis of higher alcohols and their esters, but there is still place for more. Higher alcohols are formed either by anabolism or catabolism (Ehrlich pathway) of amino acids. Esters are formed by enzymatic condensation of organic acids and alcohols. The current paper reviews the up-to-date knowledge in the pathways involving the synthesis of higher alcohols and esters by brewing yeasts. Fermentation parameters affecting yeast response during biosynthesis of these aromatic substances are also fully reviewed.

Hindfoot Alignment in Flexible Cavovarus Deformity Under Orthostatic and Coleman Block Test Positions: A Weightbearing Computed Tomography Study.

BACKGROUND: Flexible cavovarus deformity is prevalent and the Coleman block test is frequently used to assess the first ray plantarflexion malpositioning in the overall deformity as well as the flexibility of the hindfoot. The objective was to assess and compare the weightbearing computed tomography (WBCT) 3-dimensional (3D) changes in clinical and bone alignment in flexible cavovarus deformity patients when performing the Coleman block test when compared to normal standing position and to controls. METHODS: Twenty patients (40 feet) with flexible cavovarus deformity and 20 volunteer controls (40 feet) with normal foot alignment underwent WBCT imaging of the foot and ankle. Cavovarus patients were assessed in normal orthostatic and Coleman block test positions. Foot and ankle offset (FAO), hindfoot alignment angle (HAA), talocalcaneal angle (TCA), subtalar vertical angle (SVA) and talonavicular coverage angle (TNCA) and a CT-simulated soft tissue envelope image, WBCT clinical hindfoot alignment angle (WBCT-CHAA), were evaluated by 2 readers. Measurements were compared between cavovarus nonstressed and stressed positions and to controls. P values of .05 or less were considered significant. RESULTS: The intra- and interobserver intraclass correlation coefficient were good or excellent for all WBCT measurements. Cavovarus patients demonstrated significant correction of WBCT-CHAA (9.7 ± 0.4 degrees), FAO (2.6 ± 0.4%), and TNCA (8.8 ± 1.8 degrees) when performing the Coleman block test (all P values <.0001). However, WBCT-CHAA and FAO measurements were still residually deformed and significantly different from controls (P values of .001 and <.0001, respectively). TNCA values corrected to values similar to healthy controls (P = .29). No differences were observed in cavovarus patients during Coleman block test for the coronal measures: HAA, TCA, and SVA measurements. CONCLUSION: In this study, we observed improvement in the overall 3D WBCT alignment (FAO), axial plane adduction deformity (TNCA), as well as CT simulated clinical hindfoot alignment (WBCT-CHAA) in flexible cavovarus deformity patients when performing a Coleman block test. However, we did not find improvement in measures of coronal alignment of the hindfoot, indicating continued varus positioning of the hindfoot in these patients. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Staged reconstruction of the hallux for infected non-union using bulk autograft and a customized implant: Case report.

This case report illustrates the outcome of a deep infection following internal fixation of a fracture of the big toe. Hallux amputation could be avoided through staged salvage procedure. This paper can assist readers on how to effectively and safely recognize and treat this type of injury.

A finite element model to simulate femoral fractures in calves: testing different polymers for intramedullary interlocking nails.

OBJECTIVE: To verify if the finite element method can correctly estimate the performance of polyacetal and polyamide 6 intramedullary nails in stabilizing a femoral fracture in calves and to estimate the performance of a polypropylene nail in same conditions. STUDY DESIGN: Computational and experimental study. SAMPLE POPULATION: Finite element models (FEMs). METHODS: Based on a 3-dimensional finite element method (FEM) of the femoral diaphysis, 3 models were constructed to simulate an oblique simple fracture stabilized by an intramedullary nail composed of 1 of 3 distinct polymers. Models were tested under 6 loading conditions that simulated a static calf or a calf in different walking phases. Maximum bone and implant stresses were compared to yield and rupture stresses of specific materials. RESULTS: Under static conditions, all polymers were resistant to critical deformation and rupture because maximum von Mises stresses were lower than the respective yield and rupture stresses. However, during walking, maximum stresses exceeded the yield and rupture limits of the polymers, in agreement with a previous in vivo study, which used polyacetal and polyamide nails. CONCLUSIONS: FEM correctly estimated that polyacetal and polyamide 6 nails would fail to immobilize an oblique femoral diaphyseal fracture in calves that were allowed to walk freely during the early postoperative period. FEM can be useful in the development of new bovine orthopedic devices.

Initial studies of the recovery of Cu from MSWI fly ash leachates using solvent extraction.

Large volumes of ash from combustion of municipal solid waste are produced and most of it is landfilled. As this type of ash contains significant amounts of metal compounds the landfilling strategy is not optimal when considered from a resource conservation perspective. A better situation would be created if metals were recovered from the ash. In the present study leaching and solvent extraction was applied for release and separation of copper from municipal solid waste combustion fly ashes. The results showed promising results with Cu yields of 50-95%. The yield was heavily dependent on the efficiency of the initial leaching of Cu from the ash.

Staged salvage of diabetic foot with Chopart amputation and intramedullary nailing.

We present a stepwise surgical approach that can be used, in lieu of a transtibial amputation, to preserve the lower limb in the setting of severe diabetic foot infections. A 63-year-old male status post left midfoot (Lisfranc's) amputation presented to our hospital with a 4-year history of a left foot diabetic ulcer with associated purulent drainage and intermittent chills. On initial exam, the patient's left foot amputation stump was plantarflexed, grossly erythematous, and edematous. The associated diabetic foot ulcer was actively draining purulent fluid. Following workup with radiography and ultrasound, the patient was diagnosed with a post-operative infection of the midfoot at the level of the amputation stump secondary to diabetic neuropathy. Our approach to management was a staged and included (1) surgical irrigation and debridement of the distal stump wound, (2) provisional negative pressure therapy, (3) a second-look procedure, and (4) a tibiotalocalcaneal fusion was performed using a lateral transfibular and plantar approach, after wound closure and resolution of active infection was achieved. At 36-month follow-up, the patient was fully weight-bearing in stiff sole sneakers with no gross overt alteration of gait pattern. The patient scored 79 points when assessed by the hindfoot American Orthopaedic Foot and Ankle Society Ankle-Hindfoot outcome score. In the patient with diabetes and cardiological restrictions, a Chopart amputation is preferred due to the decreased level of energy expenditure required for ambulation as compared to over more proximal levels of amputation.

Biomechanical comparison of plantar-to-dorsal and dorsal-to-plantar screw fixation strength for subtalar arthrodesis.

OBJECTIVE: To compare screw fixation strength for subtalar arthrodesis. METHODS: Eight matched pairs of cadaver feet underwent subtalar joint arthrodesis with two 7.3mm cannulated screws. Randomization was used to assign screw orientation, such that one foot in each pair was assigned dorsal to plantar screw orientation (DP Group), and the other foot, plantar to dorsal orientation (PD Group). Standard surgical technique with fluoroscopy was used for each approach. Following fixation, each specimen was loaded to failure with a Bionix ® 858 MTS device, applying a downward axial force at a distance to create torque. Torque to failure was compared between DP and PD Groups using Student's t test, with p=0.05 used to determine statistical significance. RESULTS: Statistical analysis demonstrated that the mean torque to failure slightly favored the DP Group (37.3Nm) to the PD Group (32.2Nm). However, the difference between the two groups was not statistically significant (p=0.55). CONCLUSION: In subtalar arthrodesis, there is no significant difference in construct strength between dorsal-to-plantar and plantar-to-dorsal screw orientation. The approach chosen by the surgeon should be based on factors other than the biomechanical strength of the screw orientation.

Development of a new chitosan hydrogel for wound dressing.

Wound healing is a complex process involving an integrated response by many different cell types and growth factors in order to achieve rapid restoration of skin architecture and function. The present study evaluated the applicability of a chitosan hydrogel (CH) as a wound dressing. Scanning electron microscopy analysis was used to characterize CH morphology. Fibroblast cells isolated from rat skin were used to assess the cytotoxicity of the hydrogel. CH was able to promote cell adhesion and proliferation. Cell viability studies showed that the hydrogel and its degradation by-products are noncytotoxic. The evaluation of the applicability of CH in the treatment of dermal burns in Wistar rats was performed by induction of full-thickness transcutaneous dermal wounds. Wound healing was monitored through macroscopic and histological analysis. From macroscopic analysis, the wound beds of the animals treated with CH were considerably smaller than those of the controls. Histological analysis revealed lack of a reactive or a granulomatous inflammatory reaction in skin lesions with CH and the absence of pathological abnormalities in the organs obtained by necropsy, which supported the local and systemic histocompatibility of the biomaterial. The present results suggest that this biomaterial may aid the re-establishment of skin architecture.

Evaluation of concentration technologies in the design of biorefineries for the recovery of resources from vinasse.

This article reports a study of five designs of vinasse biorefineries that incorporate anaerobic bioreactors followed by a concentration technology such as evaporation, reverse osmosis, or forward osmosis. Different techniques of draw solution regeneration - evaporation, reverse osmosis, and membrane distillation - were also analyzed. Exergy analysis, a method that evaluates the resource conversion efficiency of systems, was used to compare the alternatives. The results indicated that among the alternatives analyzed, the combination of anaerobic digestion and reverse osmosis presented the highest exergy efficiency (62%). However, evaporators were the most feasible in terms of costs. Both alternatives are interesting and the final choice depends on the technology available and local economy. In any case, the treatment of 491.76 m3/h of vinasse (exergy rate of 60513.8 kW) to recover 70% of water could reduce external water requirement by 66% and generate 28% additional electricity for the sugarcane plant. In this case, the water recovery could represent an economy of 8,490,435.76 USD/year for the Brazilian alcohol industry.

Posterior quadratus lumborum block for primary total hip arthroplasty analgesia: a comparative study.

OBJECTIVE: To compare analgesia and opioid consumption for patients undergoing primary total hip arthroplasty with preoperative posterior quadratus lumborum block with patients who did not receive quadratus lumborum block. METHODS: The medical records of patients undergoing unilateral total hip arthroplasty between January 1st, 2017 and March 31, 2018 were reviewed, and 238 patients were included in the study. The primary outcome was postoperative opioid consumption in the first 24 postoperative hours. Secondary outcomes were intraoperative, post anesthesia care unit, and 48-hour opioid consumption, postoperative pain Visual Analog Scale scores, and post-anesthesia care unit length of stay. Primary and secondary endpoint data were compared between patients undergoing primary total hip arthroplasty with preoperative posterior quadratus lumborum block with patients who did not receive quadratus lumborum block. RESULTS: For the patients who received quadratus lumborum block, the 24-hour total oral morphine equivalent (milligram) requirements were lower (53.82mg±37.41), compared to the patients who did not receive quadratus lumborum block (77.59mL±58.42), with p=0.0011. Opioid requirements were consistently lower for the patients who received quadratus lumborum block at each additional assessment time point up to 48 hours. Pain Visual Analog Scale scores were lower up to 12 hours after surgery for the patients who received a posterior quadratus lumborum block, and the post-anesthesia care unit length of stay was shorter for the patients who received quadratus lumborum block. CONCLUSION: Preoperative posterior quadratus lumborum block for primary total hip arthroplasty is associated with decreased opioid requirements up to 48 hours, decreased Visual Analog Scale pain scores up to 12 hours, and shorter post-anesthesia care unit length of stay. Level of evidence: III.

Determining the distribution of granule diameter from biological sludge.

Anaerobic granule sizes from various types of anaerobic biological wastewater treatments were investigated in order to understand the influence of this characteristic on the performance of the treatment system. To date, there is no standardised methodology in the current literature, which provides details of a process to obtain data, such as a suitable sample volume, a description of the precision and limitations of the techniques used. Therefore, the aim of this protocol is to standardise the granulometry assay that can measure granule sizes accurately and quickly. In addition, the proposed methodology comprises about 1500-3000 granules in a single sample, a representative number compared to the currently applied methodologies.

ARE TRAUMATOLOGISTS TREATING OSTEOPOROSIS TO PREVENT NEW FRACTURES IN BRAZIL?

OBJECTIVES: To determine the proportion of traumatologists who investigate osteoporosis in elderly patients with fractures and recommend secondary prevention of osteoporotic fractures. METHODS: We distributed questionnaires to 244 physicians attending the 2015 Brazilian Congress of Orthopedic Trauma. We determined the respondents' profiles and assessed how they investigated and treated osteoporosis in elderly patients with fractures. RESULTS: Overall, 32% of the respondents reported that their knowledge level regarding osteoporosis ranged from 0-5 (out of 0-10). In total, 42% of the participants reported that they usually requested DXA for elderly patients with fractures and less than 30% reported prescribing supplemental calcium and/or vitamin D. We considered physicians conducting a complete treatment for the patient as those who in addition to requesting DXA prescribed supplemental calcium, vitamin D, and specific medications for their elderly patients, and recommended non-pharmacological measures. Only 0.8% of the participants fulfilled all these criteria. In addition, 47% of the traumatologists reported that they did not treat osteoporosis directly but instead, referred osteoporotic patients to a qualified physician. CONCLUSION: Less than 50% of the surveyed traumatologists investigated and performed secondary prevention against osteoporotic fractures after treating an elderly patient with a fracture. Level of evidence III, Economic and Decision Analyses - Developing an Economic or Decisions Model.

OBJETIVO: Avaliar a proporção de traumatologistas que investigam a osteoporose nos pacientes idosos com fraturas e recomendam a prevenção secundária das fraturas osteoporóticas. MÉTODOS: Distribuímos questionários para 244 médicos participantes do Congresso Brasileiro de Traumatología Ortopédica em 2015. Determinamos o perfil dos mesmos e avaliamos como os entrevistados investigam e tratam a osteoporose nos pacientes idosos com fraturas. RESULTADOS: Entre os entrevistados, 32% relataram que seu nível de conhecimento sobre osteoporose seria algo entre 0 e 5 (de 0 a 10). No total, 42% dos participantes relataram que frequentemente solicitam DXA para pacientes idosos com fraturas, mas menos de 30% relataram prescrever suplementação com cálcio e/ou vitamina D. Consideramos como prescritores do tratamento completo para o paciente aqueles médicos que, além de solicitar DXA, prescrevem suplementação de cálcio, vitamina D e medicamentos específicos para seus pacientes idosos, além de recomendar medidas não farmacológicas. Apenas 0,8% dos participantes preencheram todos esses critérios. Além disso, 47% dos traumatologistas relataram que não tratam a osteoporose, mas encaminham seus pacientes com osteoporose para um médico que o faz. CONCLUSÃO: Menos de 50% dos traumatologistas pesquisados investigam e realizam prevenção secundária contra fraturas osteoporóticas após tratamento de paciente idoso com fratura. Nível de evidência III, Análises econômicas e de decisão - Desenvolvimento de modelo econômico ou de decisão.

Hepatic abscess induced by foreign body: case report and literature review.

Hepatic abscess due to perforation of the gastrointestinal tract caused by ingested foreign bodies is uncommon. Pre-operative diagnosis is difficult as patients are often unaware of the foreign body ingestion and symptoms and imagiology are usually non-specific. The authors report a case of 62-year-old woman who was admitted with fever and abdominal pain. Further investigation revealed hepatic abscess, without resolution despite antibiotic therapy. A liver abscess resulting from perforation and intra-hepatic migration of a bone coming from the pilorum was diagnosed by surgery. The literature concerning foreign body-induced perforation of the gastrointestinal tract complicated by liver abscess is reviewed.

Media arrangement impacts cell growth in anaerobic fixed-bed reactors treating sugarcane vinasse: Structured vs. randomic biomass immobilization.

This study reports on the application of an innovative structured-bed reactor (FVR) as an alternative to conventional packed-bed reactors (PBRs) to treat high-strength solid-rich wastewaters. Using the FVR prevents solids from accumulating within the fixed-bed, while maintaining the advantages of the biomass immobilization. The long-term operation (330days) of a FVR and a PBR applied to sugarcane vinasse under increasing organic loads (2.4-18.0kgCODm-3day-1) was assessed, focusing on the impacts of the different media arrangements over the production and retention of biomass. Much higher organic matter degradation rates, as well as long-term operational stability and high conversion efficiencies (>80%) confirmed that the FVR performed better than the PBR. Despite the equivalent operating conditions, the biomass growth yield was different in both reactors, i.e., 0.095gVSSg-1COD (FVR) and 0.066gVSSg-1COD (PBR), indicating a clear control of the media arrangement over the biomass production in fixed-bed reactors.

Adaptive Portfolio Optimization for Multiple Electricity Markets Participation.

The increase of distributed energy resources, mainly based on renewable sources, requires new solutions that are able to deal with this type of resources' particular characteristics (namely, the renewable energy sources intermittent nature). The smart grid concept is increasing its consensus as the most suitable solution to facilitate the small players' participation in electric power negotiations while improving energy efficiency. The opportunity for players' participation in multiple energy negotiation environments (smart grid negotiation in addition to the already implemented market types, such as day-ahead spot markets, balancing markets, intraday negotiations, bilateral contracts, forward and futures negotiations, and among other) requires players to take suitable decisions on whether to, and how to participate in each market type. This paper proposes a portfolio optimization methodology, which provides the best investment profile for a market player, considering different market opportunities. The amount of power that each supported player should negotiate in each available market type in order to maximize its profits, considers the prices that are expected to be achieved in each market, in different contexts. The price forecasts are performed using artificial neural networks, providing a specific database with the expected prices in the different market types, at each time. This database is then used as input by an evolutionary particle swarm optimization process, which originates the most advantage participation portfolio for the market player. The proposed approach is tested and validated with simulations performed in multiagent simulator of competitive electricity markets, using real electricity markets data from the Iberian operator-MIBEL.

Biomechanical comparison of plantar-to-dorsal and dorsal-to-plantar screw fixation strength for subtalar arthrodesis / Comparação biomecânica da força de fixação de parafuso com orientação de plantar para dorsal e vice-versa para artrodese subtalar

ABSTRACT Objective To compare screw fixation strength for subtalar arthrodesis. Methods Eight matched pairs of cadaver feet underwent subtalar joint arthrodesis with two 7.3mm cannulated screws. Randomization was used to assign screw orientation, such that one foot in each pair was assigned dorsal to plantar screw orientation (DP Group), and the other foot, plantar to dorsal orientation (PD Group). Standard surgical technique with fluoroscopy was used for each approach. Following fixation, each specimen was loaded to failure with a Bionix ® 858 MTS device, applying a downward axial force at a distance to create torque. Torque to failure was compared between DP and PD Groups using Student's t test, with p=0.05 used to determine statistical significance. Results Statistical analysis demonstrated that the mean torque to failure slightly favored the DP Group (37.3Nm) to the PD Group (32.2Nm). However, the difference between the two groups was not statistically significant (p=0.55). Conclusion In subtalar arthrodesis, there is no significant difference in construct strength between dorsal-to-plantar and plantar-to-dorsal screw orientation. The approach chosen by the surgeon should be based on factors other than the biomechanical strength of the screw orientation.

RESUMO Objetivo Comparar a força de fixação dos parafusos para artrodese subtalar. Métodos Oito pares de pés de cadáveres frescos foram submetidos à artrodese da articulação subtalar com dois parafusos canulados de 7,3mm. A randomização foi usada para atribuir a orientação do parafuso, de modo que um pé em cada par foi designado com orientação de dorsal para plantar (Grupo DP), e o outro pé com orientação de plantar para dorsal (Grupo PD). Técnica cirúrgica padrão com radioscopia foi usada para os procedimentos. Após a fixação, cada amostra foi testada até a falha com um dispositivo Bionix®858 MTS, aplicando força axial descendente a uma distância para criar torque. O torque de falha foi comparado entre os Grupos DP e PD, usando o teste t de Student, com p=0,05 usado para determinar significância estatística. Resultados A análise estatística demonstrou que a média do torque até a falha favoreceu ligeiramente o Grupo DP (37,3Nm) em relação ao PD (32,2Nm). No entanto, a diferença entre os dois grupos não foi estatisticamente significativa (p=0,55). Conclusão Na artrodese subtalar, não há diferença significativa na força de compressão entre as orientações dos parafusos dorsal-plantar e plantar-dorsal. A abordagem escolhida pelo cirurgião deve ser baseada em outros fatores, sem preocupação com a força biomecânica da orientação dos parafusos.

Remoção de algas em um sistema de biofiltros submersos / Removal of algae in a submerse biofilter system

RESUMO Esta pesquisa propôs o desenvolvimento de um sistema de biofiltros submersos (SBS), modificados com base na configuração de filtros de pedra, visando ao pós-tratamento do efluente de lagoas de estabilização, inicialmente para a remoção de algas. Foram implantados 2 conjuntos de biofiltros submersos para captar esgoto tratado de duas diferentes profundidades de uma lagoa de maturação - a 60 cm (em uma zona dessa lagoa chamada superficial - ZS) e a 180 cm (em outra zona dessa lagoa chamada intermediária - ZI). Foi utilizada, como recheio dos biofiltros submersos, pedra brita nº 3, nas seguintes alturas de leito filtrante: 50, 100, 150 e 200 cm, tendo por objetivo avaliar a influência desse fator sobre a eficiência de remoção de algas mediante análise de clorofila A e outras 16 variáveis de qualidade associadas neste estudo. Obtiveram-se eficiências para demanda química de oxigênio (DQO) no intervalo de 65 a 80% para ZS e, para ZI, os resultados dessa eficiência tiveram muita variação, sem estabilidade - de forma prática, portanto, o ponto de coleta na ZI mostrou-se não recomendado. Quando às eficiências para clorofila A, para ZS, o intervalo alcançado variou de 65 a 99% e, para ZI, esses resultados foram inferiores aos da ZS. Concluiu-se que a extração a partir da zona superficial da lagoa de maturação e uma profundidade de leito entre 150 e 200 cm foram os parâmetros operacionais que levaram a um melhor desempenho global dos biofiltros submersos modificados e, mais especificamente, quanto às seguintes variáveis: DQO, demanda bioquímica de oxigênio (DBO), clorofila A e sólidos totais.

ABSTRACT This research proposed the development of a submerged biofilters system, modified based on the configuration of rock filters, aiming at the effluent post-treatment of stabilization lagoons, initially for algae removal. Two sets of submerged biofilters were implemented to collect treated sewage from two different depths of a maturation lagoon - at 60 cm (in a zone of this lagoon called superficial-SZ) and at 180 cm (in a zone of this lagoon called intermediary-IZ). It was used, as filling of submerged biofilters, gravel No. 3, at filtering layers heights of: 50, 100, 150 and 200 cm, aiming to evaluate the influence of this factor over algae removal efficiency toward chlorophyll a, and other 16 quality variables associated in this study. For SZ, efficiencies were obtained for COD in the range of 65 to 80%, and for IZ the efficiency results had a lot of variation, without stability, in a practical way, so the collection point in ZI was not recommended. For SZ efficiencies were obtained for chlorophyll a in the range of 65 to 99%, and for IZ the efficiency results were lower than those of SZ. It was concluded that the collecting from superficial zone of the maturation lagoon, and a layer depth between 150 and 200 cm, were the operational parameters that led to a better overall performance of the modified submerged biofilters, and more particularly to: COD (Chemical Oxygen Demand), BOD (Biochemical Oxygen Demand), chlorophyll a, and total solids.

Application of a 3D printed customized implant for canine cruciate ligament treatment by tibial tuberosity advancement.

Fabrication of customized implants based on patient bone defect characteristics is required for successful clinical application of bone tissue engineering. Recently a new surgical procedure, tibial tuberosity advancement (TTA), has been used to treat cranial cruciate ligament (CrCL) deficient stifle joints in dogs, which involves an osteotomy and the use of substitutes to restore the bone. However, limitations in the use of non-biodegradable implants have been reported. To overcome these limitations, this study presents the development of a bioceramic customized cage to treat a large domestic dog assigned for TTA treatment. A cage was designed using a suitable topology optimization methodology in order to maximize its permeability whilst maintaining the structural integrity, and was manufactured using low temperature 3D printing and implanted in a dog. The cage material and structure was adequately characterized prior to implantation and the in vivo response was carefully monitored regarding the biological response and patient limb function. The manufacturing process resulted in a cage composed of brushite, monetite and tricalcium phosphate, and a highly permeable porous morphology. An overall porosity of 59.2% was achieved by the combination of a microporosity of approximately 40% and a designed interconnected macropore network with pore sizes of 845 µm. The mechanical properties were in the range of the trabecular bone although limitations in the cage's reliability and capacity to absorb energy were identified. The dog's limb function was completely restored without patient lameness or any adverse complications and also the local biocompatibility and osteoconductivity were improved. Based on these observations it was possible to conclude that the successful design, fabrication and application of a customized cage for a dog CrCL treatment using a modified TTA technique is a promising method for the future fabrication of patient-specific bone implants, although clinical trials are required.