There is an increasing need for diagnostic tools that can assess the crop nitrogen (N) nutrition status during the growth cycle. In addition to the leaf chlorophyll (Chl) content, we proposed here ...the use of the leaf content of polyphenolics (Phen) as a potential indicator of crop N status. Because of their absorption features in the visible and in the UV part of the spectrum, both Chl and Phen can be measured by rapid and non-destructive optical methods. Therefore, we used two leaf-clip devices, the Minolta SPAD-502 for Chl, and the Dualex for Phen. The latter is a prototype (patent pending) that measures the UV absorbance of the leaf epidermis, which is related to the leaf Phen content. Dynamics of Phen and Chl were measured on the last fully developed leaves of two winter wheat cultivars subjected to different levels of N availability, from tillering to flowering, in 2001, 2002 and 2003. Both Phen and Chl contents were found to increase along the leaf, starting from the ligula, regardless of the stage of development. Both variables were highly correlated with the N concentration of leaves. The average Chl content of the leaf increased, and the average Phen content decreased, with the increased application of N to the field, irrespective of the growth stage, the cultivar and the year of experiment. Therefore, both Phen and Chl can be considered as probes of the crop N nutrition status. Still, the relationship between Chl and the nitrogen nutrition index (NNI), used as a reference indicator of N deficiency, was influenced by the growth stage, whereas the year of experiment affected the relationship between Phen and the NNI. We also propose the use of the simple Chl/Phen ratio as an indicator of leaf N content at the canopy level, for future application in precision agriculture. This ratio would alleviate, at least partially, the problem of gradients along leaves, and would even accentuate the differences among levels of crop N deficiencies because of the Chl and Phen inverse dependence on the crop N nutrition status.
Grape phenolic maturity is usually assessed by destructive wet chemistry in the laboratory. Yet, for precision agriculture or continuous monitoring of maturation, more rapid and non-destructive ...methods are needed. Therefore, in addition to measurements of fruit colour, a new optical method was recently proposed. It is based on the screening of fruit chlorophyll fluorescence that allows both flavonol and anthocyanin contents of intact berry skin to be measured. Here, we present the first results obtained with two commercial devices, Dualex FLAV™ and Dualex ANTH™, and a prototype, Multiplex, all based on this new method. We found that the non-contact optical sensor Multiplex has strong potential for an application in the vineyard for precision viticulture or for crop evaluation at the weighbridge.
Background and Aims
Modern viticulture requires robust, fast, non‐destructive methods to assess berry composition. We tested a chlorophyll fluorescence screening method to estimate berry phenolic ...substances.
Methods and Results
We focused on anthocyanin and flavonol in red and white cultivars. The ANTH_RG index was dependent on the cultivar anthocyanin profile. In Nebbiolo, in which dihydroxylated anthocyanins prevail, ANTH_RG was 2.4 times higher than in Barbera, in which trihydroxylated anthocyanins prevail. Considering the profiles of the two cultivars at similar anthocyanin concentration and their relative in vitro absorbance, a bathochromic shift of 10 nm emerged, which can explain the different screening effect exerted by anthocyanin on chlorophyll fluorescence. As to flavanols, we propose the calibration of a new spectroscopic index, the FLAV_UV, in coloured and white berries, finding good correlation with flavonol concentration determined analytically (R2 higher than 0.7).
Conclusions
Spectroscopic indices can estimate the concentration of anthocyanin and flavonol in grape berries.
Significance of the Study
A calibration curve for Nebbiolo, which has a distinctive anthocyanin profile, and the calibration of a new index, the FLAV_UV, able to estimate flavonol concentration in both red and white cultivars, are described for the first time. These indices can effectively be applied for non‐destructive assessment of grape flavonoid.
The popularity of unicompartmental knee arthroplasty (UKA) continues to grow among orthopaedic surgeons and robotic surgery may be helpful in obtaining a precise placement of the prosthetic ...components, thanks to the meticulous intra-operative computer study for simulating the prosthetic positioning. This may lead to longer implant survivorship as well as a reduction in intermediate and long-term prosthetic complications, despite the initial greater costs than those of manual UKA. In this preliminary study, from January 2017 and October 2017, 18 patients underwent UKA with MAKO robotic system assistance and 10 patients received UKA with NAVIO robotic system assistance. The two groups were homogeneous by age, BMI, degree of osteoarthritis involvement, and postoperative program. Patients were followed both clinically (Numeric Rating Scale NRS and Knee Injury Osteoarthritis Outcome Scores KOOS) and radiographically. At the end term follow up (2 years), no significant difference was observed for NRS and KOOS as well as for clinical parameters as an active range of motion. A significant discrepancy was detected regarding the duration of the surgery and time of using the robotic system, that appeared to be longer in the NAVIO group than that of MAKO group, likely due to the specific technical aspects that characterize these two different robotic systems. The main finding of this study is that favorable clinical and radiographical results may be obtained using a robotic approach (MAKO or NAVIO) for UKA positioning at a short follow up. Due to the lack of significant clinical differences observed between the two groups of patients at end term follow up, the "concept" of a robotic approach, more than a specific patented system, may be considered the key element for improving UKA technique and it is likely that in the near future the choice of a single specific robotic system will still be a "surgeon's preference". The results of the study add scientific evidence regarding the effective improvement of UKA results using different robotic approaches. They also show possible economic sustainability of this therapeutic strategy related to the optimal patients' performance obtained at short term follow up, suggesting that the robotic assistance may really become a key element for better long-term survivorship of unicompartmental knee arthroplasty.
Periprosthetic osteolysis: a narrative review Marmotti, A; Messina, D; Cykowska, A ...
Journal of biological regulators and homeostatic agents,
2020 Jul-Aug, Letnik:
34, Številka:
4 Suppl. 3
Journal Article
Recenzirano
Periprosthetic osteolysis is still one of the major limitations of prosthetic joints longevity. The process of this "silent" iatrogenic disease involves both mechanical and biological factors that ...initiate a local immune response in the periprosthetic tissue that eventually lead to implant loosening and failure. There are many causes of the primary aseptic loosening inside the periprosthetic microenvironment, but the most important elements are the wear debris and the cell-particle interactions. Together with implant position, micromotion, bearings, joint fluid pressure, and increased load on the joints drive the pathogenesis of the disease. This narrative review aims to summarise recent studies describing the biological and mechanical factors in the pathogenesis of osteolysis and some of the current pharmacological attempts to "rescue" a failing implant.
Transtibial femoral tunnel drilling is still an alternative technique in ACL reconstruction. Femoral interference screw divergence is a potential pitfall associated with transtibial tunnel technique, ...as angles greater than 15° jeopardize graft fixation. Our mathematical model theorizes the proper degrees of knee flexion during femoral screw insertion and the correct screwdriver position to obtain a minimal divergence of the screw in the femoral tunnel. The cadaveric study confirms our method. Mathematical model: using rototranslation matrices, a correlation is demonstrated between the ACLtibial- guide angle, the knee flexion, and the screwdriver position. A theoretical minimal divergence between femoral interference screw and the femoral tunnel is obtainable following these assumptions: 1) knee hyperflexion during femoral screw insertion is obtained adding a flexion corresponding to the ACL-tibial-guide angle to the flexion while drilling the femoral tunnel; 2) screwdriver position (through the AM portal) is kept parallel to tibial plateau at a rotation of 15° medial to tibial sagittal plane. Cadaveric study: 24 cadaver knees were used. The transtibial tunnel was drilled with an 8 mm drill bit with the help of an ACL tibial guide set at 55°. To simulate femoral tunnel direction, a 2.4 mm K. wire was drilled through the femur with a transtibial 7 mm offset femoral drill guide. To simulate the femoral screw direction, a second 2.4 mm K. wire was drilled from the femoral entry point of the first wire through the femur, with a cannulated screwdriver. Screwdriver direction and knee flexion during the simulation were obtained following two different methods: GROUP A (mathematical model group, 12 knees), screwdriver direction and knee flexion were calculated following the mathematical model; in GROUP B (control group, 12 knees), knee hyperflexion and screwdriver medialization were manually obtained by a senior surgeon. The divergence between the femoral interference screw and the femoral tunnel was identified as the angle formed by the two wires, measured on the plane formed by the direction of the wires. Mean divergence angles between the K. wires were significantly different (p< 0.05) between the groups: GROUP 1 (mathematical rule): 7.25° (SD 2.2); GROUP 2 (free-hand technique): 17.3° (SD 2.9). Our study shows that a minimal divergence between the femoral tunnel and the screwdriver can be achieved simply by following a mathematical rule for correct intraoperative knee flexion and screwdriver position without the need for any specialized instrumentation. Namely, during femoral interference screw insertion through the anteromedial portal: 1) the correct knee flexion is the sum between the knee flexion angle while drilling the transtibial femoral tunnel AND the ACL tibial guide angle used during tibial tunnel drilling; 2) Correct screwdriver position is parallel to the tibial plateau, engaging the femoral tunnel with a position of 15° medial to tibial sagittal plane. This simple concept has clinical relevance in helping the surgeons in obtaining an optimal alignment between the femoral tunnel and the femoral interference screw during transtibial ACL reconstruction. Furthermore, following the assumptions of this study, a starting knee flexion angle around 70° during femoral tunnel drilling seems preferable for ACL reconstruction when the transtibial tunnel technique is used. Indeed, because ACL-tibial-guide angles range commonly from 50° to 60° and in vivo, the maximal intraoperative knee flexion attainable is 130°, a starting knee flexion around 70° is optimal to allows for adding flexion angles up to 60° before reaching the physiological limit value of 130°.
Postoperative rehabilitation after simultaneous anterior cruciate ligament reconstruction and opening wedge high tibial osteotomy is a complex concept. Different osteotomy techniques, extremely ...selected patients, high expectations in returning to previous sport activities, and the different individual physical profile and performances make traditional chronological criteria impractical and unfeasible. This study presents a novel rehabilitation in which functional objective criteria are considered the key factors for standardizing a 4-step protocol. Each step is "individualized", based on the patient's response to the healing processes and to the different training phases, allowing for a safe return to sports competitions. This definitively implies a strict collaboration between patient, surgeon, physician and physiotherapists, as well as thorough and detailed patient education. Due to the high versatility of these new rehabilitation concepts, the application of the "individualized" steps described in this study may be broadened to include different sports medicine knee injuries that may benefit from a specific, detailed and carefully patient-centered rehabilitation project.
•Computational fluid dynamics was used to assess the thermo-fluid dynamic behaviour of an indoor vertical farming system.•In-field sensor measurements were used to set the boundary conditions for the ...simulations and to validate the results.•Indices of air flow uniformity and vapor pressure deficit distribution can be used to deeply understand the air flow within the cell and to individuate the most critical regions for plant cultivation.•In the analysed indoor farming system, upper and lower cultivation layers show a different behaviour of air flow: more symmetric the formers, less the latters.•VPD analysis show that air flow symmetry is not sufficient for optimal plant cultivation.•A combination of air flow uniformity and VPD analysis can help to optimize the plant growth and thus to reduce energy and water consumption.
In this study, computational fluid dynamics (CFD) was used to assess the thermo-fluid dynamic behaviour of an indoor vertical farming system. Experimentally driven three-dimensional k-ε steady simulations were performed using a species transport model to account for relative humidity. In-field sensor measurements were used to set the boundary conditions for the simulations and to validate the results in terms of temperature and humidity distribution within the growing cell. The entire cell, consisting of eight levels of growing tables was simulated under daylight conditions, including the heat source from LED lights in the thermo-fluid dynamic air flow field. Results helped to understand the main features of the air flow distribution. The comparison of the numerical results with measurements demonstrated the ability of the numerical approach to characterize the thermo-fluid dynamic flow field of the indoor farming system and the reliability of well-calibrated CFD simulations in controlling the air flow distribution, which is necessary to reduce energy consumption and to improve plant growth quality. Critical regions for the plant growth were identified within the farm based on the study of air speed uniformity and on the analysis of vapor pressure deficit (VPD). A growing table efficiency index was introduced based on the definitions of two dimensionless objective uniformity parameters. The analysis of these indices helps identifying differences in the fluid dynamic behaviour of the upper and lower floors of the cell and some deficiencies in the ventilation system ability to provide uniform air conditions to all the growing tables. Results show a symmetric behaviour of the left and right layers for upper floors, with tables in front of the evaporators showing better efficiencies. An opposite behaviour is observed on the lower floors, exhibiting a strong asymmetry between left and right layers. On the other hand, the VPD analysis revealed that certain regions near the evaporators and walls (with good flow uniformity) experience extreme conditions that could affect plant growth. The presented approach in this paper provides a detailed understanding of the indoor vertical farming environment and its impact on growth and yield of leafy greens. This in turn helps in the effort to optimize the vertical farm ventilation system and thus its energy, which remains the main issue of such cultivation plants.
This paper aims to investigate early responses to ozone in leaves of Fagus sylvatica (beech) and Populus maximowiczii x Populus berolinensis (poplar). The experimental setup consisted of four ...open-air (OA) plots, four charcoal-filtered (CF) open-top chambers (OTCs), and four nonfiltered (NF) OTCs. Qualitative and quantitative analyses were carried out on nonsymptomatic (CF) and symptomatic (NF and OA) leaves of both species. Qualitative analyses were performed applying microscopic techniques: Evans blue staining for detection of cell viability, CeCl3 staining of transmission electron microscope (TEM) samples to detect the accumulation of H2O2, and multispectral fluorescence microimaging and microspectrofluorometry to investigate the accumulation of fluorescent phenolic compounds in the walls of the damaged cells. Quantitative analyses consisted of the analysis of the chlorophyll a fluorescence transients (fast kinetics). The early responses to ozone were demonstrated by the Evans blue and CeCl3 staining techniques that provided evidence of plant responses in both species 1 month before foliar symptoms became visible. The fluorescence transients analysis, too, demonstrated the breakdown of the oxygen evolving system and the inactivation of the end receptors of electrons at a very early stage, both in poplar and in beech. The accumulation of phenolic compounds in the cell walls, on the other hand, was a species-specific response detected in poplar, but not in beech. Evans blue and CeCl3 staining, as well as the multispectral fluorescence microimaging and microspectrofluorometry, can be used to support the field diagnosis of ozone injury, whereas the fast kinetics of chlorophyll fluorescence provides evidence of early physiological responses.
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