In this study, the thermoelastic behaviour of three-dimensional isotropic and laminated beams is investigated. The three-dimensional beam is modelled through advanced one-dimensional finite elements ...derived via hierarchical expansion of the displacements over the cross-section. The approximation order of the displacement field is a free parameter that leads to the formulation of a family of several beam elements. The number of nodes per element is also a free parameter. Linear, quadratic and cubic variations along the beam axis are considered within the element. The temperature field is treated as an external load within the mechanical analysis and it is obtained by exactly solving Fourier's heat conduction equation. The governing algebraic equations are obtained via the Principle of Virtual Displacements. Displacements and stresses are investigated and results are validated towards three-dimensional FEM solutions. The temperature load results in a three-dimensional stress state that calls for accurate models. Numerical investigations show that the proposed finite elements yield accurate yet computationally efficient results.
A new multi-field beam model based on Carrera's Unified Formulation (CUF) is offered in this article to efficiently solve the hygro-thermal-mechanical problem of beam structures with high-fidelity. ...Several beam models have been hierarchically derived in the framework of CUF with consideration of the hygro-thermal stresses. By adopting the principle of virtual displacement, the element stiffness matrix can be derived into a compact form. The temperature and humidity profile is generated from the Fourier's heat conduction and Fick's law, respectively. With simply supported and cantilever configurations being adopted, hygro-mechanical and hygro-thermal-mechanical analyses are carried out for different beam slenderness ratios. Results are provided in terms of three-dimensional displacement and stress distributions. The proposed one-dimensional CUF-based beam model has been validated against traditional three-dimensional FEM-based solutions, and an excellent correlation has been achieved. It is found that an accurate result can be obtained through the proposed CUF-based beam model with reduced computational costs.
In this work, the thermoelastic response of functionally graded beams is studied. To this end, a family of advanced one-dimensional finite elements is derived by means of a Unified Formulation that ...is not dependent on the order of approximation of the displacements upon the beam cross-section. The temperature field is obtained via a Navier-type solution of Fourier’s heat conduction equation and it is considered as an external load within the mechanical analysis. The stiffness matrix of the elements is derived via the Principle of Virtual Displacements. Numerical results in terms of temperature, displacements and stresses distribution are provided for different beam slenderness ratios and type of material gradation. Linear, quadratic and cubic elements are used. Results are validated through comparison with three-dimensional finite elements solutions obtained by the commercial software ANSYS. It is shown that accurate results can be obtained with reduced computational costs.
The aim of this paper is to present a preliminary experience of sub-muscular primary direct-to-implant (DTI) breast reconstruction without acellular dermal matrix (ADM), after salvage mastectomy for ...local recurrence following prior irradiation.
A retrospective investigation was performed on a prospectively maintained database of breast reconstruction cases at our institution between January 2015 and December 2020. We considered only immediate DTI breast reconstructions without ADM following radiotherapy and salvage mastectomy for local recurrence, with at least a 12-month follow-up.
The study considered 18 female patients with an average of 68 years. According to the BREAST-Q questionnaire, all patients reported high levels of "satisfaction with outcome" with good "psychosocial wellness" and "physical impact" related to the reconstruction. The aesthetic evaluation showed a significant difference between the VAS score gave by the patient (mean 6.9) and the surgeon (mean 5.4). No implant exposure occurred in this series. In terms of complications, four patients (22%) suffered from wound dehiscence and were managed conservatively. Three patients (17%) required primary closure in day surgery following superficial mastectomy flap necrosis. Late capsular contracture was seen in seven patients (four Baker stage II and three Baker stage III, totally 39%); however, no patient was willing to undergo implant exchange.
DTI breast reconstruction following prior irradiation can be considered as an option in patients who are not good candidates for autologous breast reconstruction. Our general outcomes compared favorably with literature data regarding the use of staged procedures, with acceptable complication rates and levels of patient satisfaction.
Objective
The use of minimally invasive or transcatheter interventions rather than standard full sternotomy operations to treat tricuspid valve (TV) disease is increasing. The debate however is still ...open regarding venous drainage management during cardiopulmonary bypass (CPB) and wheatear or not superior and inferior vena cava should be occluded during the opening of the right atrium to avoid air entrance in the venous line. The aim of the present study is to report operative outcomes and midterm follow‐up results of minimally invasive TV surgery performed without caval occlusion.
Methods
A retrospective outcome evaluation from institutional records was performed with prospective data entry. Considered were consecutive patients who underwent right mini‐thoracotomy TV surgery isolated or combined with mitral valve surgery during the period from June 2013 to February 2020. A telephone and echocardiographic follow‐up was performed.
Results
During the study period, 68 consecutive patients underwent minimally invasive TV surgery without occlusion of cava veins. The mean age was 69 ± 14 years and 48 (70%) were female. All operations were performed safely without air‐lock during CPB. A perioperative cerebral stroke occurred in one patient. The survival at a 5‐ and 8‐year follow‐up was 100% and 79%, respectively. No severe tricuspid regurgitation was evident at echocardiographic follow‐up.
Conclusion
Our results show that performing tricuspid surgery without caval occlusion is safe. The air was captured by the active vacuum drainage system without causing damage. Midterm follow‐up data confirm that a minimally invasive approach does not alter the quality of surgery.
Punzi-loss Abudinén, F.; Bertemes, M.; Bilokin, S. ...
The European physical journal. C, Particles and fields,
2022/2, Letnik:
82, Številka:
2
Journal Article
Recenzirano
Odprti dostop
We present the novel implementation of a non-differentiable metric approximation and a corresponding loss-scheduling aimed at the search for new particles of unknown mass in high energy physics ...experiments. We call the loss-scheduling, based on the minimisation of a figure-of-merit related function typical of particle physics, a Punzi-loss function, and the neural network that utilises this loss function a Punzi-net. We show that the Punzi-net outperforms standard multivariate analysis techniques and generalises well to mass hypotheses for which it was not trained. This is achieved by training a single classifier that provides a coherent and optimal classification of all signal hypotheses over the whole search space. Our result constitutes a complementary approach to fully differentiable analyses in particle physics. We implemented this work using PyTorch and provide users full access to a public repository containing all the codes and a training example.
Endometriosis is a gynecological disease defined by the histological presence of endometrial glands and stroma outside the uterine cavity. Women with endometriosis have an increased risk of different ...types of malignancies, especially ovarian cancer and non-Hodgkin's lymphoma. Though there are several theories, researchers remain unsure as to the definitive cause of endometriosis. Our objective was to test the validity of the theory of müllerianosis for endometriosis, that is the misplacing of primitive endometrial tissue along the migratory pathway of foetal organogenesis
We have collected at autopsy 36 human female foetuses at different gestational age. We have performed a morphological and immunohistochemical study (expression of oestrogen receptor and CA125) on the pelvic organs of the 36 foetuses included en-block and totally analyzed.
In 4 out of 36 foetuses we found presence of misplaced endometrium in five different ectopic sites: in the recto-vaginal septum, in the proximity of the Douglas pouch, in the mesenchimal tissue close to the posterior wall of the uterus, in the rectal tube at the level of muscularis propria, and in the wall of the uterus. All these sites are common location of endometriosis in women.
We propose that a cause of endometriosis is the dislocation of primitive endometrial tissue outside the uterine cavity during organogenesis.
B-flavor tagging at Belle II Akopov, N.; Banerjee, Sw; Bauer, M. ...
The European physical journal. C, Particles and fields,
04/2022, Letnik:
82, Številka:
4
Journal Article
Recenzirano
Odprti dostop
We report on new flavor tagging algorithms developed to determine the quark-flavor content of bottom (
) mesons at Belle II. The algorithms provide essential inputs for measurements of quark-flavor ...mixing and charge-parity violation. We validate and evaluate the performance of the algorithms using hadronic
decays with flavor-specific final states reconstructed in a data set corresponding to an integrated luminosity of 62.8 fb
-
1
, collected at the
resonance with the Belle II detector at the SuperKEKB collider. We measure the total effective tagging efficiency to be
ε
eff
=
(
30.0
±
1.2
(
stat
)
±
0.4
(
syst
)
)
%
for a category-based algorithm and
ε
eff
=
(
28.8
±
1.2
(
stat
)
±
0.4
(
syst
)
)
%
for a deep-learning-based algorithm.
The dipolar approximation model that describes the heat delivered by a nanoparticle under continuous light irradiation provides a relation in which the dissipated power is proportional to the ...extinction cross-section. This relation works fairly well for small particles in which all the energy is absorbed, but fails for larger structures due to the non-negligible power scattered in the free space that does not contribute to heat generation. Here we show that, if we consider the light-induced dipolar field in the calculation of the dissipated power, we recover the proportionality with the absorption cross-section of the nanoparticle.
Exercise intervention improves macrovascular function in metabolic syndrome (MeS) patients, but few studies have evaluated the effect of exercise on microcirculatory dysfunction, which plays a key ...role in the development of MeS and its correlated organ damage. We carried out this intervention study to evaluate the influence of an aerobic and resistance training on skin microvascular reactivity in MeS patients.
Postocclusive reactive hyperemia (PORH) of the forearm skin was evaluated, by laser-Doppler flowmetry, before and after a 12-week program of aerobic and resistance training in 15 MeS patients referring to our Lipid Metabolism Outpatients Clinic, together with anthropometric, fitness and metabolic parameters; 15 matched MeS patients who did not exercise, served as a control group. The exercise training consisted of 2 sessions/week of aerobic and resistant exercise.
Following exercise program, we observed a significant reduction in body weight, fat mass, fasting blood glucose, serum HbA1c and triglycerides, while HDL-cholesterol significantly increased. The exercise-treated group experienced a significant improvement in the area of hyperemia (AH) after PORH, and in all fitness parameters: VO2max, strength on the pulldown lat machine, chest press, leg press and leg extension. A significant correlation emerged between the increase in AH and the reduction in HbA1c and between increase in AH and strength at the chest press, and at the leg extension.
Our study showed that a short-term combined aerobic-resistance training positively affects microvascular reactivity in MeS patients. This improvement is correlated with the reduction of HbA1c and fitness parameters, and particularly with increased muscle strength at the upper and lower limbs.
PDF
