Effect of Laser Microcutting on Thermo-Mechanical Properties of NiTiCu Shape Memory Alloy

Carlo Alberto Biff,Paola Bassani,Marco Carnevale,Nora Lecis,Antonietta Loconte,Barbara Previtali,Ausonio Tuissi 대한금속·재료학회 2014 METALS AND MATERIALS International Vol.20 No.1

The machining of shape memory alloys (SMAs), such as NiTi based alloys, is a very interesting and rele-vant topic for several industrial applications in the biomedical, sensor and actuator fields. Laser technology isone of the most suitable methods for the manufacturing of products in the aforementioned fields, mainlywhen small and precise features have to be included. Due to the thermal nature of this process, study of itseffect on the functional properties of these materials is needed. Except for binary NiTi, few results on thelaser machining of NiTi based alloys are available in the literature. In this work, thin sheets of Ni40Ti50Cu10(at.%) were processed by a fibre laser and the effect of process speed on the material properties was analy-sed. Scanning electronic microscopy was adopted for observation of the laser cut edges’ morphology. Chemi-cal composition of the processed material was evaluated by energy dispersion spectroscopy and nanohardnessmeasurements were used to estimate the heat affected zone. SMA functional properties were studied on bothbase and laser machined material. These characteristics are affected by laser machining for the presence ofmelted material; this effect can be minimised by increasing the laser process speed.

Noninvasive Urodynamic Evaluation

Carlos Arturo Levi D’Ancona,Jose Bassani,João Carlos Almeida 대한배뇨장애요실금학회 2012 International Neurourology Journal Vol.16 No.3

The longevity of the world’s population is increasing, and among male patients, complaints of lower urinary tract symptoms (LUTS) are growing. Testing to diagnose LUTS and to differentiate between the various causes should be quick, easy, cheap, specific, not too bothersome for the patient, and noninvasive or minimally so. Urodynamic evaluation is the gold standard for diagnosing bladder outlet obstruction (BOO) but presents some inconveniences such as embarrassment, pain, and dysuria; furthermore,19% of cases experience urinary retention, macroscopic hematuria, or urinary tract infection. A greater number of resources in the diagnostic armamentarium could increase the opportunity for selecting less invasive tests. A number of groups have risen to this challenge and have formulated and developed ideas and technologies to improve noninvasive methods to diagnosis BOO. These techniques start with flowmetry, an increase in the interest of ultrasound, and finally the performance of urodynamic evaluation without a urethral catheter. Flowmetry is not sufficient for confirming a diagnosis of BOO. Ultrasound of the prostate and the bladder can help to assess BOO noninvasively in all men and can be useful for evaluating the value of BOO at assessment and during treatment of benign prostatic hyperplasia patients in the future. The great advantages of noninvasive urodynamics are as follows: minimal discomfort, minimal risk of urinary tract infection, and low cost. This method can be repeated many times, permitting the evaluation of obstruction during clinical treatment. A urethral connector should be used to diagnose BOO, in evaluation for surgery, and in screening for treatment. In the future, noninvasive urodynamics can be used to identify patients with BOO to initiate early medical treatment and evaluate the results. This approach permits the possibility of performing surgery before detrusor damage occurs.

Quantification of Saponins in Extractive Solution of Mate Leaves (Ilex paraguariensis A. St. Hil.)

Geraldo Ceni Coelho,Simone B. Gnoatto,Valquı´ria L. Bassani,Eloir Paulo Schenkel 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.2

Mate (Ilex paraguariensis A. St. Hil.) is a raw material used to prepare popular beverages in South America, whose healthy effects have been pointed out. The leaves and stems of mate contain a complex assemblage of saponins, mainly ursolic acid and oleanolic acid glycosides, and their quantification presents difficulties such as weak cromophorous sites and interference of other compounds. On the other hand, the sugar moieties are a chief character that distinguishes them. We developed and validated a high-performance liquid chromatography method using a refractometer detector for quantifying the major saponins in extractive solution of mate leaves. The validation indicates the suitability of the method, presenting linearity in the concentration range between 102.5 to 854.0μg/mL to matesaponin 1 and between 103.0 to 515.0μg/mL to matesaponin 3. The repeatability coefficient of variation was 4.70% and 6.61% for matesaponin 1 and matesaponin 3, respectively. The inter-day coefficient of variation was 6.77% and 7.79% for matesaponin 1 and matesaponin 3, respectively. The analysis of plants from Brazilian States Mato Grosso do Sul and Rio Grande do Sul showed the predominance of matesaponins 1, 2, and 3 in the corresponding extractive solution. The sum of these three saponins ranged between 3 and 10mg/g for mature leaves in the majority of sampled plants.

Technological Characterization and Stability of Ilex paraguariensis St. Hil. Aquifoliaceae (Maté) Spray-Dried Powder

Francini K.J. Yatsu,Greice S. Borghetti,Valquiria L. Bassani 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.4

The present work was designed to produce an Ilex paraguariensis spray-dried powder (SDP), in semi-industrial scale, in order to characterize its technological and chemical properties as well as to evaluate the thermal stability and photostability of the main polyphenol constituents. The yield of the spray-drying process was satisfactory (67%). The resulting SDP showed to be a material presenting spherical particles with a mean size of 19.6 μm, smooth surface, and good flow properties. The four polyphenol compounds previously reported for the species—neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, and rutin—were identified. Regarding the photostability test, the polyphenols present in the SDP proved to be stable against ultraviolet C radiation for 48 hours, independently of the packaging material. In the thermal stability test, the polyphenols were demonstrated to be hygroscopic and responsive to temperature (40°C) under an atmosphere of high relative humidity (75%) for 4 months, especially when the SDP was conditioned in permeable flasks. These findings demonstrate that heat and residual moisture content play an important role in the stability of the polyphenols and reinforce the relevance of conditioning SDP in humid tight packages under low temperatures.

Bone-Preserving Decompression Procedures Have a Minor Effect on the Flexibility of the Lumbar Spine

Costa, Francesco,Ottardi, Claudia,Volkheimer, David,Ortolina, Alessandro,Bassani, Tito,Wilke, Hans-Joachim,Galbusera, Fabio The Korean Neurosurgical Society 2018 Journal of Korean neurosurgical society Vol.61 No.6

Objective : To mitigate the risk of iatrogenic instability, new posterior decompression techniques able to preserve musculoskeletal structures have been introduced but never extensively investigated from a biomechanical point of view. This study was aimed to investigate the impact on spinal flexibility caused by a unilateral laminotomy for bilateral decompression, in comparison to the intact condition and a laminectomy with preservation of a bony bridge at the vertebral arch. Secondary aims were to investigate the biomechanical effects of two-level decompression and the quantification of the restoration of stability after posterior fixation. Methods : A universal spine tester was used to measure the flexibility of six L2-L5 human spine specimens in intact conditions and after decompression and fixation surgeries. An incremental damage protocol was applied : 1) unilateral laminotomy for bilateral decompression at L3-L4; 2) on three specimens, the unilateral laminotomy was extended to L4-L5; 3) laminectomy with preservation of a bony bridge at the vertebral arch (at L3-L4 in the first three specimens and at L4-L5 in the rest); and 4) pedicle screw fixation at the involved levels. Results : Unilateral laminotomy for bilateral decompression had a minor influence on the lumbar flexibility. In flexion-extension, the median range of motion increased by 8%. The bone-preserving laminectomy did not cause major changes in spinal flexibility. Two-level decompression approximately induced a twofold destabilization compared to the single-level treatment, with greater effect on the lower level. Posterior fixation reduced the flexibility to values lower than in the intact conditions in all cases. Conclusion : In vitro testing of human lumbar specimens revealed that unilateral laminotomy for bilateral decompression and bone-preserving laminectomy induced a minor destabilization at the operated level. In absence of other pathological factors (e.g., clinical instability, spondylolisthesis), both techniques appear to be safe from a biomechanical point of view.

Auger nanoprobe : quantitative elemental analysis at the nanometer scale

Eugenie MARTINEZ,Wael HOURANI,Viktoriia GORBENKO,Jean-Paul BARNES,Romain CIPRO,Jeremy MOEYAERT,Franck BASSANI,Thierry BARON 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8