340 research outputs found
The Use of Six Sigma to Assess Two Prostheses for Immediate Breast Reconstruction
Breast reconstruction is fundamental and urgent for patients in order to avoid future psychological and physical issues. That’s why immediate breast reconstruction has been requested increasingly in the last years. In this study two prosthesis with different structures and properties were compared according the aesthetic appearance (BREAST-Q© was employed) and five complications (seroma, hematoma, infections, dehiscence and red breast syndrome). The overall population was composed by 56 patients: 24 received a Tutomesh prosthesis and 32 received a Surgimend prosthesis. The DMAIC (define, measure, analyse, improve and control) cycle was implemented as a problem-solving strategy of the Six Sigma to compare the prostheses. While statistically significant difference between the two groups wasn’t found according to the overall BREAST-Q© (p-value = 0.674), the number of complications of the two groups resulted statistically different (p-value of chi-square test less than 0.001). Although it is not possible to understand from this study the reasons of the differences between the complications, this research proved that Surgimend and Tutomesh prostheses can be both implanted safely for immediate breast reconstruction since the higher costs of Surgimend could be neutralized with its lower hospitalization compared to Tutomesh. © 2021, Springer Nature Switzerland AG
Interplay between curvature and Planck-scale effects in astrophysics and cosmology
Several recent studies have considered the implications for astrophysics and
cosmology of some possible nonclassical properties of spacetime at the Planck
scale. The new effects, such as a Planck-scale-modified energy-momentum
(dispersion) relation, are often inferred from the analysis of some quantum
versions of Minkowski spacetime, and therefore the relevant estimates depend
heavily on the assumption that there could not be significant interplay between
Planck-scale and curvature effects. We here scrutinize this assumption, using
as guidance a quantum version of de Sitter spacetime with known Inonu-Wigner
contraction to a quantum Minkowski spacetime. And we show that, contrary to
common (but unsupported) beliefs, the interplay between Planck-scale and
curvature effects can be significant. Within our illustrative example, in the
Minkowski limit the quantum-geometry deformation parameter is indeed given by
the Planck scale, while in the de Sitter picture the parameter of quantization
of geometry depends both on the Planck scale and the curvature scalar. For the
much-studied case of Planck-scale effects that intervene in the observation of
gamma-ray bursts we can estimate the implications of "quantum spacetime
curvature" within robust simplifying assumptions. For cosmology at the present
stage of the development of the relevant mathematics one cannot go beyond
semiheuristic reasoning, and we here propose a candidate approximate
description of a quantum FRW geometry, obtained by patching together pieces
(with different spacetime curvature) of our quantum de Sitter. This
semiheuristic picture, in spite of its limitations, provides rather robust
evidence that in the early Universe the interplay between Planck-scale and
curvature effects could have been particularly significant.Comment: 26 pages
Relative Locality in -Poincar\'e
We show that the -Poincar\'e Hopf algebra can be interpreted in the
framework of curved momentum space leading to the relativity of locality
\cite{AFKS}. We study the geometric properties of the momentum space described
by -Poincar\'e, and derive the consequences for particles propagation
and energy-momentum conservation laws in interaction vertices, obtaining for
the first time a coherent and fully workable model of the deformed relativistic
kinematics implied by -Poincar\'e. We describe the action of boost
transformations on multi-particles systems, showing that in order to keep
covariant the composed momenta it is necessary to introduce a dependence of the
rapidity parameter on the particles momenta themselves. Finally, we show that
this particular form of the boost transformations keeps the validity of the
relativity principle, demonstrating the invariance of the equations of motion
under boost transformations.Comment: 24 pages, 4 figures, 1 table. v2 matches accepted CQG versio
Comparing Two Approaches for Thyroidectomy: A Health Technology Assessment through DMAIC Cycle
Total thyroidectomy is very common in endocrine surgery and the haemostasis can be obtained in different ways across surgery; recently, some devices have been developed to support this surgical phase. In this paper, a health technology assessment is conducted through the define, measure, analyse, improve, and control cycle of the Six Sigma methodology to compare traditional total thyroidectomy with the surgical operation performed through a new device in an overall population of 104 patients. Length of hospital stay, drain output, and time for surgery were considered the critical to qualities in order to compare the surgical approaches which can be considered equal regarding the organizational, ethical, and security impact. Statistical tests (Kolmogorov–Smirnov, t test, ANOVA, Mann–Whitney, and Kruskal–Wallis tests) and visual management diagrams were employed to compare the approaches, but no statistically significant difference was found between them. Considering these results, this study shows that the introduction of the device to perform total thyroidectomy does not guarantee appreciable clinical advantages. A cost analysis to quantify the economic impact of the device into the practice could be a future development. Healthy policy leaders and clinicians who are requested to make decisions regarding the supply of biomedical technologies could benefit from this research
Unusual metachronous isolated inguinal lymph node metastasis from adenocarcinoma of the sigmoid colon
This study aimed to describe an unusual case of metachronous isolated inguinal lymph nodes metastasis from sigmoid carcinoma. A 62-year-old man was referred to our department because of an obstructing sigmoid carcinoma. Colonoscopy showed the obstructing lesion at 30 cm from the anal verge and abdominal CT revealed a sigmoid lesion infiltrating the left lateral abdominal wall. The patient underwent a colonic resection extended to the abdominal wall. Histology showed an adenocarcinoma of the colon infiltrating the abdominal wall with iuxtacolic nodal involvement. Thirty three months after surgery abdominal CT and PET scan revealed a metastatic left inguinal lymph node involvement. The metastatic lymph node was found strictly adherent to the left iliac-femoral artery and encompassing the origin of the left inferior epigastric artery. Histology showed a metachronous nodal metastasis from colonic adenocarcinoma. Despite metastastic involvement of inguinal lymph node from rectal cancer is a rare but well known clinical entity, to the best of our knowledge, this is the first report of inguinal metastasis from a carcinoma of the left colon. Literature review shows only three other similar reported cases: two cases of inguinal metastasis secondary to adenocarcinoma of the cecum and one case of axillary metastasis from left colonic carcinoma. A metastatic pathway through superficial abdominal wall lymphatic vessels could be possible through the route along the left inferior epigastric artery. The solitary inguinal nodal involvement from rectal carcinoma could have a more favorable prognosis. In the case of nodal metastasis to the body surface lymph nodes from colonic carcinoma, following the small number of such cases reported in the literature, no definitive conclusions can be drawn
Exploring gravitational theories beyond Horndeski
We have recently proposed a new class of gravitational scalar-tensor theories
free from Ostrogradski instabilities, in arXiv:1404.6495. As they generalize
Horndeski theories, or "generalized" galileons, we call them G. These
theories possess a simple formulation when the time hypersurfaces are chosen to
coincide with the uniform scalar field hypersurfaces. We confirm that they
contain only three propagating degrees of freedom by presenting the details of
the Hamiltonian formulation. We examine the coupling between these theories and
matter. Moreover, we investigate how they transform under a disformal
redefinition of the metric. Remarkably, these theories are preserved by
disformal transformations that depend on the scalar field gradient, which also
allow to map subfamilies of G into Horndeski theories.Comment: 33 pages, added comments and corrected typos as in JCAP versio
Hyperfunctioning Parathyroid Giant Adenoma
Purpose: The objective of this paper is to report the management and treatment of a 47-year-old
patient admitted with multiple problems including asthenia, nausea and bradycardia, and was
diagnosed with a giant parathyroid adenoma.
Case report: A 47-year-old man was admitted to the Department of General Surgery for acute
and worsening asthenia, nausea and bradycardia. Blood tests showed hypercalcemia, hypophosporemia,
very high serum parathormone level, so that he was diagnosed with primary
hyperparathyroidism. Cervical ultrasonography and scintigraphy with technetium 99 mTc Methoxyisobutylisonitrile
(99 mTc-MIBI) showed the presence of positive nodule at the isthmus
of the thyroid gland. The patient underwent neck exploration. Intra-operative iPTH essay was
measured. A giant parathyroid adenoma was identified and excised, with no macroscopic signs
of malignancy.
Discussion and conclusion: Hyper functioning parathyroid giant adenoma can present with
typical symptoms of hypercalcemic crisis: ECG alterations, kidney failure, emotional lability,
confusion, delirium, psychosis, asthenia, epilepsy. Elective treatment is the excission. The
surgical technique contemplates neck exploration and to ensure the finding of the adenoma,
previously identified with imaging tests. It is necessary to measure intra-operative iPTH assay
Cosmological tests of coupled Galileons
We investigate the cosmological properties of Galileon models which admit Minkowski space as a stable solution in vacuum. This is motivated by stable, positive tension brane world constructions that give rise to Galileons. We include both conformal and disformal couplings to matter and focus on constraints on the theory that arise because of these couplings. The disformal coupling to baryonic matter is extremely constrained by astrophysical and particle physics effects. The disformal coupling to photons induces a cosmological variation of the speed of light and therefore distorsions of the Cosmic Microwave Background spectrum which are known to be very small. The conformal coupling to baryons leads to a variation of particle masses since Big Bang Nucleosynthesis which is also tightly constrained. We consider the background cosmology of Galileon models coupled to Cold Dark Matter (CDM), photons and baryons and impose that the speed of light and particle masses respect the observational bounds on cosmological time scales. We find that requiring that the equation of state for the Galileon models must be close to -1 now restricts severely their parameter space and can only be achieved with a combination of the conformal and disformal couplings. This leads to large variations of particle masses and the speed of light which are not compatible with observations. As a result, we find that cosmological Galileon models are viable dark energy theories coupled to dark matter but their couplings, both disformal and conformal, to baryons and photons must be heavily suppressed making them only sensitive to CDM
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