We report a very rare case of bipolar fracture with dislocation of the proximal phalanx or floating proximal phalanx of the toe. The literature has shown that closed reduction gives a lesser chance ...of success considering the inherent anatomy of the foot. We report a case of a 40-year-old male with an open injury to his right foot involving bipolar dislocation of the proximal phalanx of the third toe with extensor digitorum longus tendon injury and fracture of the neck of the fourth proximal phalanx of the right foot. With the realization that open reduction and Kirschner wire fixation are good options in patients with such a presentation, a prompt and accurate diagnosis with a treatment plan was made, which lead to clinical success.
Elastic electron-proton scattering (e-p) and the spectroscopy of hydrogen atoms are the two methods traditionally used to determine the proton charge radius, r
. In 2010, a new method using muonic ...hydrogen atoms
found a substantial discrepancy compared with previous results
, which became known as the 'proton radius puzzle'. Despite experimental and theoretical efforts, the puzzle remains unresolved. In fact, there is a discrepancy between the two most recent spectroscopic measurements conducted on ordinary hydrogen
. Here we report on the proton charge radius experiment at Jefferson Laboratory (PRad), a high-precision e-p experiment that was established after the discrepancy was identified. We used a magnetic-spectrometer-free method along with a windowless hydrogen gas target, which overcame several limitations of previous e-p experiments and enabled measurements at very small forward-scattering angles. Our result, r
= 0.831 ± 0.007
± 0.012
femtometres, is smaller than the most recent high-precision e-p measurement
and 2.7 standard deviations smaller than the average of all e-p experimental results
. The smaller r
we have now measured supports the value found by two previous muonic hydrogen experiments
. In addition, our finding agrees with the revised value (announced in 2019) for the Rydberg constant
-one of the most accurately evaluated fundamental constants in physics.
Genome-wide association studies (GWASs) have identified genetic loci associated with the risk of Alzheimer's disease (AD), but the molecular mechanisms by which they confer risk are largely unknown. ...We conducted a metabolome-wide association study (MWAS) of AD-associated loci from GWASs using untargeted metabolic profiling (metabolomics) by ultraperformance liquid chromatography-mass spectrometry (UPLC-MS). We identified an association of lactosylceramides (LacCer) with AD-related single-nucleotide polymorphisms (SNPs) in
(
= 5.0 × 10
to 1.3 × 10
). We showed that plasma LacCer concentrations are associated with cognitive performance and genetically modified levels of LacCer are associated with AD risk. We then showed that concentrations of sphingomyelins, ceramides, and hexosylceramides were altered in brain tissue from
knockout mice, compared with wild type (WT) (
= 0.049-1.4 × 10
), but not in a mouse model of amyloidosis. Furthermore, activation of microglia increases intracellular concentrations of hexosylceramides in part through induction in the expression of sphingosine kinase, an enzyme with a high control coefficient for sphingolipid and ceramide synthesis. Our work suggests that the risk for AD arising from functional variations in
is mediated at least in part through ceramides. Modulation of their metabolism or downstream signaling may offer new therapeutic opportunities for AD.
We present new precision measurements of the elastic electron-proton scattering cross section for momentum transfer (Q^{2}) up to 15.75 (GeV/c)^{2}. Combined with existing data, these provide an ...improved extraction of the proton magnetic form factor at high Q^{2} and double the range over which a longitudinal or transverse separation of the cross section can be performed. The difference between our results and polarization data agrees with that observed at lower Q^{2} and attributed to hard two-photon exchange (TPE) effects, extending to 8 (GeV/c)^{2} the range of Q^{2} for which a discrepancy is established at >95% confidence. We use the discrepancy to quantify the size of TPE contributions needed to explain the cross section at high Q^{2}.
Animal studies have suggested that early stress is associated with alterations in the hippocampus, a brain area that plays a critical role in learning and memory. The purpose of this study was to ...measure both hippocampal structure and function in women with and without early childhood sexual abuse and the diagnosis of posttraumatic stress disorder (PTSD).
Thirty-three women participated in this study, including women with early childhood sexual abuse and PTSD (N=10), women with abuse without PTSD (N=12), and women without abuse or PTSD (N=11). Hippocampal volume was measured with magnetic resonance imaging in all subjects, and hippocampal function during the performance of hippocampal-based verbal declarative memory tasks was measured by using positron emission tomography in abused women with and without PTSD.
A failure of hippocampal activation and 16% smaller volume of the hippocampus were seen in women with abuse and PTSD compared to women with abuse without PTSD. Women with abuse and PTSD had a 19% smaller hippocampal volume relative to women without abuse or PTSD.
These results are consistent with deficits in hippocampal function and structure in abuse-related PTSD.
The last word in anal fistula surgery has not been written. The literature is unclear on which patient should undergo a pre-operative magnetic resonance imaging MRI. Most guidelines are clear that ...complex and recurrent fistulae, or those with a background of inflammatory bowel disease, should undergo an MRI evaluation, but otherwise the guidelines are hazy and ill defined. In this study, over a 3-month period, all patients who clinically presented with anal fistula underwent MRI of the ano-rectal region. The clinical findings on digital rectal examination DRE were compared to the final radiological diagnosis, and the peri-operative findings. The fidelity of the MRI diagnosis was the endpoint of the analysis, as was the impact on the operative strategy. A change in operative course was brought about by the MRI, in a percentage of 16.1% which is quite significant. None of the patients had an endo-anal ultrasound as it is not part of our protocol. It is concluded that the addition of the MRI changed the surgical approach in a significant proportion of patients with fistula in ano and consequently it is now part of our regular workup of every anal fistula patient, to do an MRI preoperatively. By adding MRI, our recurrence rates came down significantly which is quite evident in the follow-up.
We measure ^{2}H(e,e^{'}p)n cross sections at 4-momentum transfers of Q^{2}=4.5±0.5 (GeV/c)^{2} over a range of neutron recoil momenta p_{r}, reaching up to ∼1.0 GeV/c. We obtain data at fixed ...neutron recoil angles θ_{nq}=35°, 45°, and 75° with respect to the 3-momentum transfer qover →. The new data agree well with previous data, which reached p_{r}∼500 MeV/c. At θ_{nq}=35° and 45°, final state interactions, meson exchange currents, and isobar currents are suppressed and the plane wave impulse approximation provides the dominant cross section contribution. We compare the new data to recent theoretical calculations, where we observe a significant discrepancy for recoil momenta p_{r}>700 MeV/c.
The MUon Scattering Experiment, MUSE, at the Paul Scherrer Institute, Switzerland, investigates the proton charge radius puzzle, lepton universality, and two-photon exchange, via simultaneous ...measurements of elastic muon-proton and electron-proton scattering. The experiment uses the PiM1 secondary beam channel, which was designed for high precision pion scattering measurements. We review the properties of the beam line established for pions. We discuss the production processes that generate the electron and muon beams, and the simulations of these processes. Simulations of the π/μ/e beams through the channel using TURTLE and G4beamline are compared. The G4beamline simulation is then compared to several experimental measurements of the channel, including the momentum dispersion at the intermediate focal plane and target, the shape of the beam spot at the target, and timing measurements that allow the beam momenta to be determined. Finally, we conclude that the PiM1 channel can be used for high precision π, μ, and e scattering.
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