1,564 research outputs found

    Recurring Sacral Stress Fractures in the Male Distance Runner

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    Reccurring Sacral Stress Fractures in the Male Distance Runner Waugh TJ, Stoller GL, Brooks EK, Dailey SW: Miami University Oxford, Ohio Background: A twenty year old male collegiate distance runner (170 cm and 62 kg) complained of low back pain in March 2015. The patient reported right sided low back tightness that felt like a bad spasm traveling from the lower back down into the lower leg. History of this runner revealed a non-displaced stress fracture in the left sacral ala with a stress reaction on the right sacral ala in November 2013. In April 2014, the distance runner possessed yet another sacral stress fracture. In March 2015, an assessment was made that the patient presented an acute case of piriformis syndrome due to lack of athletic participation. As two weeks went by with no positive results through rehabilitation, worsening pain, and given the pre-existing conditions of the patient, the Team Physician ordered an MRI. Differential Diagnosis: It is possible that the runner could have had an acute disc herniation, muscle strain, degenerative disc disease, or spondylolisthesis. A vertebral compression fracture, sacroiliac joint dysfunction, lumbar facet arthropathy, and sciatica are all differential diagnoses that the clinicians in this case needed to be aware of. It is also important to assess the possibilities of a lumbosacral strain and a sacroiliac joint sprain. Treatment: The MRI report revealed a high grade stress reaction in the right sacral ala. A non-displaced stress fracture in the right superior portion of the left sacral ala was also discovered. The patient was told to rest without any exercise for four to six weeks. After the stress fracture was resolved, the athlete has been encouraged not to participate in any repeated load-bearing types of activities until the source of the problem has been identified. Uniqueness: There is an uncommon nature of sacral stress fractures in males. It is important to realize that individuals who are constantly participating in repeating load-bearing activities are more prone to sacral stress fractures. Sacral stress fractures normally present themselves in women who have the female athlete triad. Research has shown that the influence of energy balance and hormonal fluctuations are significant factors associated with injuries in amenorrheic female athletes. The testosterone levels in young men normally lead to healthy and strong bones. This case report is a prime example that has the potential to teach clinicians all over to always look at the big picture and keep in mind all of the possible differential diagnoses. Conclusions: Physician's have hypothesized that the calcium level in this patient is too high which is causing parathyroid levels to decrease, resulting in low bone density. Since calcium and the parathyroid hormone have an inverse relationship, moderation between the two is essential. However, if one is too high, the other is too low decreasing bone density. Another hypothesis is that low testosterone levels in the patient are causing low bone density. This rare case is far from over as there is numerous investigative work to still be done. Clinical Application: Correctly diagnosing a sacral stress fracture is very difficult due to the wide range of differential diagnoses that its symptoms can present. Clinicians should never rule out the possibility of a sacral stress fracture when clients present low back pain, diffuse buttocks pain, and a history of repetitive loading actively. Although the clinicians in this case did not originally think this injury was another sacral stress fracture, they never ruled out the possibility due to the patient's described pain and pre-existing conditions. The clinicians in this report considered all possible diagnoses before making an assessment. Further research still needs to be performed in order to provide the most effective treatment and outcomes for future patients. Word Count: 59

    Nuclear Magnetic Resonance

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    Contains research objectives and reports on five research projects

    Nuclear Magnetic Resonance and Hyperfine Structure

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    Contains reports on five research projects

    Nuclear Magnetic Resonance and Hyperfine Structure

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    Contains research objectives and reports on six research objectives

    Nuclear Magnetic Resonance and Hyperfine Structure

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    Contains reports on three research projects

    Differential effects of the phosphatidylinositol 4-kinases, PI4KIIα and PI4KIIIβ, on Akt activation and apoptosis

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    In this study, we investigated the role of PI4P synthesis by the phosphatidylinositol 4-kinases, PI4KIIα and PI4KIIIβ, in epidermal growth factor (EGF)-stimulated phosphoinositide signaling and cell survival. In COS-7 cells, knockdown of either isozyme by RNA interference reduced basal levels of PI4P and PI(4,5)P2, without affecting receptor activation. Only knockdown of PI4KIIα inhibited EGF-stimulated Akt phosphorylation, indicating that decreased PI(4,5)P2 synthesis observed by loss of either isoform could not account for this PI4KIIα-specific effect. Phospholipase Cγ activation was also differentially affected by knockdown of either PI4K isozyme. Overexpression of kinase-inactive PI4KIIα, which induces defective endosomal trafficking without reducing PI(4,5)P2 levels, also reduced Akt activation. Furthermore, PI4KIIα knockdown profoundly inhibited cell proliferation and induced apoptosis as evidenced by the cleavage of caspase-3 and its substrate poly(ADP-ribose) polymerase. However, in MDA-MB-231 breast cancer cells, apoptosis was observed subsequent to knockdown of either PI4KIIα or PI4KIIIβ and this correlated with enhanced proapoptotic Akt phosphorylation. The differential effects of phosphatidylinositol 4-kinase knockdown in the two cell lines lead to the conclusion that phosphoinositide turnover is inhibited through PI4P substrate depletion, whereas impaired antiapoptotic Akt signaling is an indirect consequence of dysfunctional endosomal trafficking

    Spectroscopic Evidence for an Oxazolone Structure in Anionic b-Type Peptide Fragments

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    Infrared spectra of anionic b-type fragments generated by collision induced dissociation (CID) from deprotonated peptides are reported. Spectra of the b2 fragments of deprotonated AlaAlaAla and AlaTyrAla have been recorded over the 800–1800 cm–1 spectral range by multiple-photon dissociation (MPD) spectroscopy using an FTICR mass spectrometer in combination with the free electron laser FELIX. Structural characterization of the b-type fragments is accomplished by comparison with density functional theory calculated spectra at the B3LYP/6-31++G(d,p) level for different isomeric structures. Although diketopiperazine structures represent the energetically lowest isomers, the IR spectra suggest an oxazolone structure for the b2 fragments of both peptides. Deprotonation is shown to occur on the oxazolone α-carbon, which leads to a conjugated structure in which the negative charge is practically delocalized over the entire oxazolone ring, providing enhanced gas-phase stability

    Plastisol Foaming Process. Decomposition of the Foaming Agent, Polymer Behavior in the Corresponding Temperature Range and Resulting Foam Properties

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    The decomposition of azodicarbonamide, used as foaming agent in PVC - plasticizer (1/1) plastisols was studied by DSC. Nineteen different plasticizers, all belonging to the ester family, two being polymeric (polyadipates), were compared. The temperature of maximum decomposition rate (in anisothermal regime at 5 K min-1 scanning rate), ranges between 434 and 452 K. The heat of decomposition ranges between 8.7 and 12.5 J g -1. Some trends of variation of these parameters appear significant and are discussed in terms of solvent (matrix) and viscosity effects on the decomposition reactions. The shear modulus at 1 Hz frequency was determined at the temperature of maximum rate of foaming agent decomposition, and differs significantly from a sample to another. The foam density was determined at ambient temperature and the volume fraction of bubbles was used as criterion to judge the efficiency of the foaming process. The results reveal the existence of an optimal shear modulus of the order of 2 kPa that corresponds roughly to plasticizer molar masses of the order of 450 ± 50 g mol-1. Heavier plasticizers, especially polymeric ones are too difficult to deform. Lighter plasticizers such as diethyl phthalate (DEP) deform too easily and presumably facilitate bubble collapse

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
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