2,674 research outputs found
LITTLE THINGS in 3D: robust determination of the circular velocity of dwarf irregular galaxies
Dwarf Irregular galaxies (dIrrs) are the smallest stellar systems with
extended HI discs. The study of the kinematics of such discs is a powerful tool
to estimate the total matter distribution at these very small scales. In this
work, we study the HI kinematics of 17 galaxies extracted from the `Local
Irregulars That Trace Luminosity Extremes, The HI Nearby Galaxy Survey' (LITTLE
THINGS). Our approach differs significantly from previous studies in that we
directly fit 3D models (two spatial dimensions plus one spectral dimension)
using the software BAROLO, fully exploiting the information in the
HI datacubes. For each galaxy we derive the geometric parameters of the HI disc
(inclination and position angle), the radial distribution of the surface
density, the velocity-dispersion () profile and the rotation curve.
The circular velocity (V), which traces directly the galactic
potential, is then obtained by correcting the rotation curve for the asymmetric
drift. As an initial application, we show that these dIrrs lie on a baryonic
Tully-Fisher relation in excellent agreement with that seen on larger scales.
The final products of this work are high-quality, ready-to-use kinematic data
( and ) that we make publicly available. These
can be used to perform dynamical studies and improve our understanding of these
low-mass galaxies.Comment: 36 pages, 28 figures, 2 tables. Submitted to MNRAS (revised version
after the referee report). The final rotation curves can be downloaded from
http://www.filippofraternali.com/styled-9/index.htm
Extra-articular tenodesis combined with an anterior cruciate ligament reconstruction in acute anterior cruciate ligament tear in elite female football players
PURPOSE: The growing popularity of elite soccer among female participants has led to increased incidents of anterior cruciate ligament (ACL) ruptures. Many authors underline a positive glide after ACL reconstruction (ACLR), especially in women. In fact, an isolated intra-articular ACLR may be inadequate to control rotational instability after a combined injury of the ACL and the peripheral structures of the knee. Extra-articular procedures are sometimes used in primary cases displaying excessive antero-lateral rotatory instability. The purpose of this case series was to report subjective and objective outcomes after combined ACL and lateral extra-articular tenodesis (LET) with a minimum 4-year follow-up in a selected high-risk population of elite female football players.
METHODS: Between January 2007 and December 2010, 16 elite Italian female football players were included in the study. All patients underwent the same surgical technique: anatomical ACLR with autogenous semitendinosus and gracilis tendons. After the intra-articular reconstruction was performed, an additional extra-articular MacIntosh modified Coker-Arnold procedure was carried out. Patients were assessed pre- and post-operatively with the subjective and objective International Knee Documentation Committee (IKDC) evaluation form, Tegner activity scale (TAS) and Lysholm score. Joint laxity was assessed with KT-1000 by measuring the side-to-side (S/S) differences in displacement at manual maximum (mm) testing.
RESULTS: At a mean follow-up of 72.6 ± 8.1 months, two independent examiners reviewed all players. All of the patients had a fully recovered range of motion. Lachman test was negative in all patients (100 %). The evaluation of joint laxity and clinical evaluation showed a statistically significant improvement. No patients experienced complication or a re-rupture.
DISCUSSION: The rationale of combining extra-articular procedures with ACLR is to restrict the internal rotation of the reconstructed knee, taking advantage of its long lever arm and thus providing more stability in the rotational axis and preventing the ACL graft from undergoing further excessive strain.
CONCLUSIONS: The combination of an LET with ACLR in elite female football players demonstrated excellent results in terms of subjective scales, post-operative residual laxity and re-rupture rate with no complication, and a complete return to sport activity
Chest pain caused by multiple exostoses of the ribs: A case report and a review of literature
Abstract
The aim of this paper is to report an exceptional case of
multiple internal exostoses of the ribs in a young patient
affected by multiple hereditary exostoses (MHE) coming
to our observation for chest pain as the only symptom
of an intra-thoracic localization. A 16 years old patient
with familiar history of MHE came to our observation
complaining a left-sided chest pain. This pain had increased
in the last months with no correlation to a
traumatic event. The computed tomography (CT) scan
revealed the presence of three exostoses located on the
left third, fourth and sixth ribs, all protruding into the
thoracic cavity, directly in contact with visceral pleura.
Moreover, the apex of the one located on the sixth rib
revealed to be only 12 mm away from pericardium. Patient
underwent video-assisted thoracoscopy with an additional
4-cm mini toracotomy approach. At the last 1-year followup,
patient was very satisfied and no signs of recurrence or
major complication had occured. In conclusion, chest pain
could be the only symptom of an intra-thoracic exostoses
localization, possibly leading to serious complications.
Thoracic localization in MHE must be suspected when
patients complain chest pain. A chest CT scan is indicated
to confirm exostoses and to clarify relationship with surrounding
structures. Video-assisted thoracoscopic surgery
can be considered a valuable option for exostoses removal,
alone or in addiction to a mini-thoracotomy approach, in
order to reduce thoracotomy morbidity
Sirtuins and redox signaling interplay in neurogenesis, neurodegenerative diseases, and neural cell reprogramming
Since the discovery of Neural Stem Cells (NSCs) there are still mechanism to be clarified, such as the role of mitochondrial metabolism in the regulation of endogenous adult neurogenesis and its implication in neurodegeneration. Although stem cells require glycolysis to maintain their stemness, they can perform oxidative phosphorylation and it is becoming more and more evident that mitochondria are central players, not only for ATP production but also for neuronal differentiation's steps regulation, through their ability to handle cellular redox state, intracellular signaling, epigenetic state of the cell, as well as the gut microbiota-brain axis, upon dietary influences. In this scenario, the 8-oxoguanine DNA glycosylase (OGG1) repair system would link mitochondrial DNA integrity to the modulation of neural differentiation. On the other side, there is an increasing interest in NSCs generation, from induced pluripotent stem cells, as a clinical model for neurodegenerative diseases (NDs), although this methodology still presents several drawbacks, mainly related to the reprogramming process. Indeed, high levels of reactive oxygen species (ROS), associated with telomere shortening, genomic instability, and defective mitochondrial dynamics, lead to pluripotency limitation and reprogramming efficiency's reduction. Moreover, while a physiological or moderate ROS increase serves as a signaling mechanism, to activate differentiation and suppress self-renewal, excessive oxidative stress is a common feature of NDs and aging. This ROS-dependent regulatory effect might be modulated by newly identified ROS suppressors, including the NAD(+)-dependent deacetylase enzymes family called Sirtuins (SIRTs). Recently, the importance of subcellular localization of NAD synthesis has been coupled to different roles for NAD in chromatin stability, DNA repair, circadian rhythms, and longevity. SIRTs have been described as involved in the control of both telomere's chromatin state and expression of nuclear gene involved in the regulation of mitochondrial gene expression, as well as in several NDs and aging. SIRTs are ubiquitously expressed in the mammalian brain, where they play important roles. In this review we summarize the current knowledge on how SIRTs-dependent modulation of mitochondrial metabolism could impact on neurogenesis and neurodegeneration, focusing mainly on ROS function and their role in SIRTs-mediated cell reprogramming and telomere protection
Antiplatelet therapy in elderly patients with acute coronary syndrome: Between scientific evidence and future perspectives.
Dual antiplatelet therapy (DAPT) is an important strategy for reducing cardiovascular events (CV) after an acute coronary syndrome (ACS). Elderly patients undergoing DAPT have a higher risk of bleeding than younger patients for a variety of reasons. Stratification of thrombotic/hemorrhagic risk is mandatory in order to decide on the type and duration of DAPT. The percentage of patients ≥ 75 years represented in clinical trials is not large, so very often elderly people are prescribed treatment protocols only experimented on younger patients with a lower hemorrhagic risk. However, even in patients aged ≥ 75 treated with invasive or conservative therapy, after an ACS, a DAPT with aspirin 80-100 mg/day plus a P2Y12 receptor inhibitor for 12 months is recommended. In elderly patients, DAPT should be considered a dynamic process that can be modified over time based on the patient's clinical conditions, or any other necessities (non-procrastinating surgical interventions, comorbid-like effects that can increase hemorrhagic risk). In patients with moderate-high or very high hemorrhagic risk, DAPT treatment should last less than 12 months. A prolongation of DAPT beyond 12 months in this setting is limited to a very low percentage of patients, after careful assessment of ischemic/hemorrhagic profile
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