UNASSIGNED: Gravity impact has been mainly evaluated in mature teeth related to debris extrusion, even though it may affect the amount of apically extruded irrigant. In the literature the influence of gravity on the amount of apically extruded irrigant in immature teeth has been studied by a 45o inclined plate to mimic the position of the maxillary teeth and 90o for the mandibular teeth. However, patients are positioned horizontally in the dental chair while treatment. There is no study in the literature testing the horizontal position to mimic the clinical settings realistically.
UNASSIGNED: The aim of this study was to evaluate the influence of various irrigation systems on the amount of extruded irrigant in simulated immature maxillary and mandibular teeth irrigated in vertical and horizontal positions.
UNASSIGNED: Twenty-five maxillary central incisors with an apical opening of 1.3 mm in diameter were included. Irrigation procedures were performed with EndoVac, closed-ended, and open-ended needles using a VATEA peristaltic pump. The amount of apically extruded irrigant was determined using a microbalance. Statistical analysis was performed using the Kruskal-Wallis test.
UNASSIGNED: The EndoVac system caused almost no irrigant extrusion in all tested positions (P > 0.05); however, closed-ended and open-ended needles extruded more irrigant in a mandibular vertical position compared to maxillary vertical (P < 0.05) and maxillary horizontal positions (P < 0.05). Open-ended needles extruded the highest amount of irrigant.
UNASSIGNED: The EndoVac macrocannula is a more reliable and safer irrigation system as it prevents irrigant extrusion independent of the position of the tooth.

BACKGROUND: Facial massage is empirically known to be associated with morphological changes, such as improvements in facial sagging. However, quantified objective evaluations of massage-induced changes have not been performed to date. This preliminary pilot study aimed to verify the effectiveness of facial massages by using breakthrough computed tomographic technology.
METHODS: Five healthy adult volunteers (three women and two men; age, 29-37 years) were enrolled, and computed tomography (CT) examinations using a 320 detectors-spiral CT system known as 320-multidetector-row CT (MDCT) were performed before and after facial massages. Each participant performed a self-massage twice daily for 2 weeks. Massage-induced changes in the cheeks and the superficial musculoaponeurotic system (SMAS) were analyzed by two radiologists on a workstation with a high-accuracy imaging analysis system.
RESULTS: After facial massage, the malar top became thinner by -0.8% ± 0.45% and shifted cranially and horizontally over a distance of 3.9 ± 1.94 mm. The SMAS-height, defined as the highest vertical distance of the SMAS, increased by 2.6% ± 2.6%. The change rate in cheek thickness and SMAS-height showed a significant correlation (r = -0.63; P < 0.05). These changes were attributed to the lifting and tightening effects of facial massage.
CONCLUSIONS: We conducted a detailed analysis of the effects of facial massages by using the breakthrough CT technology. Our results provide useful information for beauty treatments and could contribute to the collection of objective scientific evidence for facial massages.

Reaching for an object in space forms the basis for many activities of daily living and is important in rehabilitation after stroke and in other neurological and orthopedic conditions. It has been the object of motor control and neuroscience research for over a century, but studies often constrain movement to eliminate the effect of gravity or reduce the degrees of freedom. In some studies, aging has been shown to reduce target accuracy, with a mechanism suggested to be impaired corrective movements. We sought to explore how such changes in accuracy relate to changes in finger, shoulder and elbow movements during performance of reaching movements with the normal effects of gravity, unconstrained hand movement, and stable target locations. Three-dimensional kinematic data and electromyography were collected in 14 young (25 ± 6 years) and 10 older adults (68 ± 3 years) during second-long reaches to 3 targets aligned vertically in front of the participants. Older adults took longer to initiate a movement than the young adults and were more variable and inaccurate in their initial and final movements. Target height had greater effect on trajectory curvature variability in older than young adults, with angle variability relative to target position being greater in older adults around the time of peak speed. There were significant age-related differences in use of the multiple degrees of freedom of the upper extremity, with less variability in shoulder abduction in the older group. Muscle activation patterns were similar, except for a higher biceps-triceps co-contraction and tonic levels of some proximal muscle activation. These results show an age-related deficit in the motor planning and online correction of reaching movements against a predictable force (i.e., gravity) when it is not compensated by mechanical support.

BACKGROUND: The effectiveness of facial massage is often explained by the resulting increases in the blood and lymphatic flow. However, it is difficult to explain the lifting effect on the cheeks. The aim of this study was to analyze facial mobility to further current understanding of the effectiveness of facial massage.
METHODS: Two kinds of analytical methods were designed using a cadaveric head as well as advanced computed tomography (CT). The cadaveric face was divided into three sections, and three different colors of ink were injected into each section. It was kept in a supine position for 24 hours, and the ink distribution was observed. Upright and supine CT examinations were performed on six healthy adult volunteers. The images of both were superimposed by a three-dimensional image analysis system, and changes in facial contours were analyzed.
RESULTS: The three colors of ink spread craniocaudally and were distributed differently from the gravitational vector. When both CT images were superimposed, two distinct lines were formed, which represented overlapping of the facial contours due to the two different CT images. These lines were found to correspond to the border of each color of the ink.
CONCLUSIONS: Focusing on the mobility of the face, the soft tissue of the face had vertical mobility, and it was speculated that this mobility is involved in the effectiveness of facial massage. Our results could provide useful information for cosmetic treatment and contribute to the collection of scientific knowledge for anti-aging medicine.

UNASSIGNED: Retrospective upright MRI study.
UNASSIGNED: To validate the presence of positive and negative nerve root sedimentation signs on multi-positional MRI in the upright position and explore the relationship between negative nerve root sedimentation and gravity.
UNASSIGNED: T2-weighted axial multi-positional images in the upright position at the intervertebral disc levels from L1-L2 to L4-L5 in 141 patients with non-specific low back pain were retrospectively assessed. A positive sedimentation sign was defined as the absence of nerve root sedimentation or the absence of dorsal conglomeration of nerve roots within the dural sac. A negative sedimentation sign was defined as nerve root sedimentation dorsally or dorso-laterally like a horseshoe. Intra-and inter-observer reliability was evaluated. The relationship between sedimentation sign and dural sac cross-sectional area (CSA), anterior-posterior (AP) diameter was also explored.
UNASSIGNED: The kappa value of intra-observer reliability was 0.962 and inter-observer reliability was 0.925. Both positive and negative sedimentation signs did appear at all 4 lumbar levels, including L1/2, L2/3, L3/4 and L4/5. A positive sedimentation sign was associated with significantly decreased dural sac CSA and AP diameter at L2/3, L3/4 or L4/5 level when compared to negative sedimentation sign.
UNASSIGNED: Both negative and positive sedimentation signs appeared at the L1/2, L2/3, L3/4, and L4/5 levels on the upright MRI, which suggested that the presence of nerve roots sedimenting dorsally in patients may not be associated with gravity. Moreover, the current study supports that sedimentation signs on multi-positional MRI images could have the same diagnostic functions as on MRI images.

Using rotors to expose animals to different levels of hypergravity is an efficient means of understanding how altered gravity affects physiological functions, interactions between physiological systems and animal development. Furthermore, rotors can be used to prepare space experiments, e.g., conducting hypergravity experiments to demonstrate the feasibility of a study before its implementation and to complement inflight experiments by comparing the effects of micro- and hypergravity. In this paper, we present a new platform called the Gravitational Experimental Platform for Animal Models (GEPAM), which has been part of European Space Agency (ESA)\'s portfolio of ground-based facilities since 2020, to study the effects of altered gravity on aquatic animal models (amphibian embryos/tadpoles) and mice. This platform comprises rotors for hypergravity exposure (three aquatic rotors and one rodent rotor) and models to simulate microgravity (cages for mouse hindlimb unloading and a random positioning machine (RPM)). Four species of amphibians can be used at present. All murine strains can be used and are maintained in a specific pathogen-free area. This platform is surrounded by numerous facilities for sample preparation and analysis using state-of-the-art techniques. Finally, we illustrate how GEPAM can contribute to the understanding of molecular and cellular mechanisms and the identification of countermeasures.

Using advanced virtual reality technology, we demonstrate that exposure to virtual inclinations visually simulating inclined walking induces gait modulations in a manner consistent with expected gravitational forces (i.e., acting upon a free body), suggesting vision-based perception of gravity. The force of gravity critically impacts the regulation of our movements. However, how humans perceive and incorporate gravity into locomotion is not well understood. In this study, we introduce a novel paradigm for exposing humans to incongruent sensory information under conditions constrained by distinct gravitational effects, facilitating analysis of the consistency of human locomotion with expected gravitational forces. Young healthy adults walked under conditions of actual physical inclinations as well as virtual inclinations. We identify and describe \'braking\' and \'exertion\' effects - locomotor adaptations accommodating gravito-inertial forces associated with physical inclines. We show that purely visual cues (from virtual inclinations) induce consistent locomotor adaptations to counter expected gravity-based changes, consistent with indirect prediction mechanisms. Specifically, downhill visual cues activate the braking effect in anticipation of a gravitational boost, whereas uphill visual cues promote an exertion effect in anticipation of gravitational deceleration. Although participants initially rely upon vision to accommodate environmental changes, a sensory reweighting mechanism gradually reprioritizes body-based cues over visual ones. A high-level neural model outlines a putative pathway subserving the observed effects. Our findings may be pivotal in designing virtual reality-based paradigms for understanding perception and action in complex environments with potential translational benefits.

Thoracentesis can be accomplished by active aspiration or drainage with gravity. This trial investigated whether gravity drainage could protect against negative pressure-related complications such as chest discomfort, re-expansion pulmonary edema, or pneumothorax compared with active aspiration.
This prospective, multicenter, single-blind, randomized controlled trial allocated patients with large free-flowing effusions estimated ≥ 500 mL 1:1 to undergo active aspiration or gravity drainage. Patients rated chest discomfort on 100-mm visual analog scales prior to, during, and following drainage. Thoracentesis was halted at complete evacuation or for persistent chest discomfort, intractable cough, or other complication. The primary outcome was overall procedural chest discomfort scored 5 min following the procedure. Secondary outcomes included measures of discomfort and breathlessness through 48 h postprocedure.
A total of 142 patients were randomized to undergo treatment, with 140 in the final analysis. Groups did not differ for the primary outcome (mean visual analog scale score difference, 5.3 mm; 95% CI, -2.4 to 13.0; P = .17). Secondary outcomes of discomfort and dyspnea did not differ between groups. Comparable volumes were drained in both groups, but the procedure duration was significantly longer in the gravity arm (mean difference, 7.4 min; 95% CI, 10.2 to 4.6; P < .001). There were no serious complications.
Thoracentesis via active aspiration and gravity drainage are both safe and result in comparable levels of procedural comfort and dyspnea improvement. Active aspiration requires less total procedural time.
ClinicalTrials.gov; No.: NCT03591952; URL: www.clinicaltrials.gov.

The capacity for auditory-motor coordination (AMC) is shared by several species, among which humans are most flexible in coordinating with tempo changes. We investigated how humans lose this tempo flexibility at their upper rate limit, and the effect of skill level on this phenomenon. Seven skilled street dancers, including a world champion, and 10 non-dancers were instructed to bend their knees according to a metronome beat in a standing position at eight constant beat frequencies (3.8-5 Hz). Although maximum frequency of movement during the task was 4.8 Hz in the non-dancers and 5.0 Hz in the dancers, the rate limit for AMC was 4.1 Hz in the non-dancers and 4.9 Hz in the dancers. These results suggest that the loss of AMC was not due to rate limit of movement execution but rather to a constraint on the AMC process. In addition, mediation analysis revealed that a kinematic bias (i.e. the extent of knee flexion during the task) causally affected the extent of phase wandering via mediating factors (e.g. the extent to which movement frequency was reduced relative to the beat frequency). These results add evidence that gravity acts as constraint on AMC involving vertical rhythmic movement.

Most intracranial aneurysms morphologic studies focused on characterization of size, location, aspect ratio, relationship to the surrounding vasculature and hemodynamics. However, the spatial orientation with respect to the gravity direction has not been taken into account although it could trigger various hemodynamic conditions. The present work addresses this possibility. It was divided in two parts: 1) the orientations of 18, 3D time-of-flight MRI (3D TOF MRI), scans of saccular aneurysms were analyzed. This investigation suggested that there was no privileged orientation for cerebral aneurysms. The aneurysms were oriented in the brain as follows: 9 - down, 9 - up; 11 - right, 7 - left; 6 - front, 12 - back. 2) Based on these results, subsidiary in vitro experiments were performed, analyzing the behavior of red blood cells (RBCs) within a silicone model of aneurysm before and after flow diverter stent (FDS) deployment in the parent vessel. These experiments used a test bench that reproduces physiological pulsatile flow conditions for two orientations: an aneurysm sack pointing either up (opposite to gravitational force) and down (along the gravitational force). The results showed that the orientation of an aneurysm significantly affects the intra-aneurysmal RBCs behavior after stenting, and therefore that gravity can affect the intra-aneurysm behavior of RBCs. This suggests that the patient׳s aneurysm orientation could impact the outcome of the FDS treatment. The implementation of this effect in patient-specific numerical and preoperative decision support techniques could contribute to better understand the intrasaccular biological and hemodynamic events induced by FDS.