Seismic Assessment of Arch Dams Using Fragility Curves

In the present paper, the IDA approach is applied to analyzing a thin high arch dam. The parameters of Sa, PGA and PGV are used as intensity measure (IM) and the overstressed area (OSA) is utilized as engineering demand parameter (EDP) and then, three limit states are assigned to the considered structure using the IDA curves. Subsequently, fragility curves are calculated and it is showed that the PGA is a better parameter to be taken as IM. In addition, it is found that the utilizing the proposed methodology, quantifying the qualitative limit states is probable. At last, having the fragility curves and considering their slope in addition to the other routine data which can be extracted from these curves, one may be able to conclude that in what performance level the considered dam body seems to be weak and needs retrofitting works

Novel complexing agents for the efficient separation of actinides and remediation of actinide-contaminated sites

Research into the coordination chemistry of transactinide elements should provide us with new fundamental knowledge about structure, geometry, and stability of these metal complexes. Our approach involves the design, synthesis, and characterization of {open_quotes}expanded porphyrin{close_quotes} macrocyclic ligands which coordinate the actinide metal cations with high thermodynamic affinity and kinetic stability. We can use the knowledge from understanding the fundamental coordination chemistry of these elements as a stepping stone to heavy metal detoxification, radioactive waste cleanup, and possibly radioactive isotope separation. The critical components of this research endeavor, along with the viability of metal complex formation, will be correlated to ring size and core geometry of the ligand and, the atomic radius, oxidation state, coordination geometry and coordination number of the transactinium metal ion. These chelating agents may have certain applications to the solution of some radioactive waste problems if they can be attached to polymer supports and used to chemically separate the radioactive components in waste

Dietary nitrate-induced increases in human muscle power: High versus low responders

Maximal neuromuscular power is an important determinant of athletic performance and also quality of life, independence, and perhaps even mortality in patient populations. We have shown that dietary nitrate (NO3- ), a source of nitric oxide (NO), improves muscle power in some, but not all, subjects. The present investigation was designed to identify factors contributing to this interindividual variability. Healthy men (n = 13) and women (n = 7) 22-79 year of age and weighing 52.1-114.9 kg were studied using a randomized, double-blind, placebo-controlled, crossover design. Subjects were tested 2 h after ingesting beetroot juice (BRJ) either containing or devoid of 12.3 ± 0.8 mmol of NO3- . Plasma NO3- and nitrite (NO2- ) were measured as indicators of NO bioavailability and maximal knee extensor speed (Vmax ), power (Pmax ), and fatigability were determined via isokinetic dynamometry. On average, dietary NO3- increased (P < 0.05) Pmax by 4.4 ± 8.1%. Individual changes, however, ranged from -9.6 to +26.8%. This interindividual variability was not significantly correlated with age, body mass (inverse of NO3- dose per kg), body mass index (surrogate for body composition) or placebo trial Vmax or fatigue index (in vivo indicators of muscle fiber type distribution). In contrast, the relative increase in Pmax was significantly correlated (r = 0.60; P < 0.01) with the relative increase in plasma NO2- concentration. In multivariable analysis female sex also tended (P = 0.08) to be associated with a greater increase in Pmax. We conclude that the magnitude of the dietary NO3- -induced increase in muscle power is dependent upon the magnitude of the resulting increase in plasma NO2- and possibly female sex

Is sentinel node mapping possible in surgically removed ectopic axillary breast cancer? A case report

We reported a 24-year-old female patient with the history of ectopic axillary breast cancer which was removed surgically. Sentinel node mapping was performed for lymphatic axillary staging of this patient with two injections of the 99m-Tc-phytate in both ends of the surgical scar. Lymphoscintigraphy showed an axillary sentinel node which was harvested during surgery and was not pathologically involved. Our case showed that sentinel node mapping is possible for ectopic axillary breast cancer patients even after excisional biopsy of the index lesion

Lymphatic mapping and sentinel node biopsy in endometrial cancer — a feasibility study using cervical injection of radiotracer and blue dye

BACKGROUND: The aim of this study was to evaluate the feasibility and accuracy of sentinel lymph node (SLN) detection using preoperative lymphoscintigraphy and intra-operative gamma probe/blue dye for endometrial cancer patients. MATERIAL AND METHODS: Twenty four consecutive patients with endometrial cancer were recruited. All patients underwent lymphatic mapping and sentinel node biopsy using combined intracervical radiotracer and blue dye injections. Pelvic lymph node dissection was performed for all patients. Para-aortic lymphadenectomy was done in high risk patients. All SLNs were examined by frozen section and Hematoxylin and Eosin (H&amp;E) permanent sections. RESULTS: Pre-operative lymphoscintigraphy showed at least one SLN in 21/24 patients. Intra-operatively, at least one SLN could be harvested by gamma probe and/or blue dye methods. A total of 95 SLNs were detected. Four SLNs were detected only by blue dye, 42 only by radiotracer, and 49 were hot/blue. Median number of SLN per patient was 3. Three patients had positive pelvic lymph nodes. All of them had positive SLN (no false negative case). Frozen section could identify SLN involvement in two of three patients with positive pathology. CONCLUSION: Lymphatic mapping and sentinel node biopsy is feasible and accurate in endometrial cancer patients using combined radiotracer and blue dye methods. Frozen section accuracy was lower and underscores the importance of expert pathologists for SLN mapping technique.

Nonlinear dynamic analysis of moving bilayer plates resting on elastic foundations

The aim of this study is to investigate the dynamic response of axially moving two-layer laminated plates on the Winkler and Pasternak foundations. The upper and lower layers are formed from a bidirectional functionally graded (FG) layer and a graphene platelet (GPL) reinforced porous layer, respectively. Henceforth, the combined layers will be referred to as a two-dimensional (2D) FG/GPL plate. Two types of porosity and three graphene dispersion patterns, each of which is distributed through the plate thickness, are investigated. The mechanical properties of the closed-cell layers are used to define the variation of Poisson’s ratio and the relationship between the porosity coefficients and the mass density. For the GPL reinforced layer, the effective Young’s modulus is derived with the Halpin-Tsai micro-system model, and the rule of mixtures is used to calculate the effective mass density and Poisson’s ratio. The material of the upper 2D-FG layer is graded in two directions, and its effective mechanical properties are also derived with the rule of mixtures. The dynamic governing equations are derived with a first-order shear deformation theory (FSDT) and the von K´arm´an nonlinear theory. A combination of the dynamic relaxation (DR) and Newmark’s direct integration methods is used to solve the governing equations in both time and space. A parametric study is carried out to explore the effects of the porosity coefficients, porosity and GPL distributions, material gradients, damping ratios, boundary conditions, and elastic foundation stiffnesses on the plate response. It is shown that both the distributions of the porosity and graphene nanofillers significantly affect the dynamic behaviors of the plates. It is also shown that the reduction in the dynamic deflection of the bilayer composite plates is maximized when the porosity and GPL distributions are symmetric

Now I See [travel aid for the visually impaired]

The ability to live independently is a significant and desirable quality for the visually impaired; however, moving around without direct help from another individual can be a difficult feat. At VisuAid, we are developing Now I See, our new travel aid device for the visually impaired, that will provide our clients with a novel way to perceive their environment. Through a depth camera, the user’s surroundings will be examined and any obstacles (including pits) will be reported through a vibratory interface worn on the forehead. With this information, the user will be able to ‘sense’ the obstacles and their relative positions, thereby acknowledging and avoiding them. Also, by moving their head they will be able to estimate the size of an obstacle as the camera will detect its edges

Geometrically nonlinear thermo-mechanical analysis of graphene-reinforced moving polymer nanoplates

The main target of this study is to investigate nonlinear transient responses of moving polymer nano-size plates fortified by means of Graphene Platelets (GPLs) and resting on a Winkler-Pasternak foundation under a transverse pressure force and a temperature variation. Two graphene spreading forms dispersed through the plate thickness are studied, and the Halpin-Tsai micro-mechanics model is used to obtain the effective Young's modulus. Furthermore, the rule of mixture is employed to calculate the effective mass density and Poisson's ratio. In accordance with the first order shear deformation and von Kármán theory for nonlinear systems, the kinematic equations are derived, and then nonlocal strain gradient scheme is used to reflect the effects of nonlocal and strain gradient parameters on small-size objects. Afterwards, a combined approach, kinetic dynamic relaxation method accompanied by Newmark technique, is hired for solving the time-varying equation sets, and Fortran program is developed to generate the numerical results. The accuracy of the current model is verified by comparative studies with available results in the literature. Finally, a parametric study is carried out to explore the effects of GPL's weight fractions and dispersion patterns, edge conditions, softening and hardening factors, the temperature change, the velocity of moving nanoplate and elastic foundation stiffness on the dynamic response of the structure. The result illustrates that the effects of nonlocality and strain gradient parameters are more remarkable in the higher magnitudes of the nanoplate speed

Leiomyosarcoma with Unusual Macroscopic Features: A Case Report

Uterine sarcoma is a rare tumor of mesodermal origin, accounting for 2-6% of uterine malignancies. Leiomyosarcoma (LMS) has been reported in only 1% of all uterine malignancies and is regarded as the most common primary uterine sarcoma. Herein, we present a case of LMS with unusual macroscopic features. The patient was a 61-year-old woman with LMS, which consisted of a large cystic mass (88×136 mm), containing six liters of brownish fluid on the right side of the pelvis and abdomen. The fundus of the uterus was ruptured by the solid part of the tumor. For treatment, total hysterectomy, salpingo-oophorectomy and the optimal resection of tumoral parts were carried out. Overall, the distinctive biological behavior and poor overall survival of uterine sarcoma challenge the post-operative management of this tumor. According to the one-year follow-up, the patient was disease-free. Unfortunately, no further information is at hand beyond this period