Disrupted White Matter Microstructure of the Cerebellar Peduncles in Scholastic Athletes After Concussion.

Concussion, or mild traumatic brain injury (mTBI), is a major public health concern, linked with persistent post-concussive syndrome, and chronic traumatic encephalopathy. At present, standard clinical imaging fails to reliably detect traumatic axonal injury associated with concussion and post-concussive symptoms. Diffusion tensor imaging (DTI) is an MR imaging technique that is sensitive to changes in white matter microstructure. Prior studies using DTI did not jointly investigate white matter microstructure in athletes, a population at high risk for concussive and subconcussive head traumas, with those in typical emergency room (ER) patients. In this study, we determine DTI scalar metrics in both ER patients and scholastic athletes who suffered concussions and compared them to those in age-matched healthy controls. In the early subacute post-concussion period, athletes demonstrated an elevated rate of regional decreases in axial diffusivity (AD) compared to controls. These regional decreases of AD were especially pronounced in the cerebellar peduncles, and were more frequent in athletes compared to the ER patient sample. The group differences may indicate differences in the mechanisms of the concussive impacts as well as possible compound effects of cumulative subconcussive impacts in athletes. The prevalence of white matter abnormality in cerebellar tracts lends credence to the hypothesis that post-concussive symptoms are caused by shearing of axons within an attention network mediated by the cerebellum, and warrant further study of the correlation between cerebellar DTI findings and clinical, neurocognitive, oculomotor, and vestibular outcomes in mTBI patients

The effect of pregnancy on orthodontic tooth movement in rats

Introduction: The purpose of this study was to investigate the effect of pregnancy on orthodontic tooth movement in Wistar rats. Material and Methods: Forty eight female three-month old Wistar rats with an average weight of 250 ±25 g r were selected and randomly divided into two experimental (pregnant) and control groups (non-pregnant). Maxillary central incisors were tipped distally by insertion of springs exerting 30g force. Two, seven and fourteen days after spring insertion animals were sacrificed. Then the mesioincisal distance between maxillary incisors were measured. Subsequently, histological sections were prepared to count osteoclasts under a light microscope. The data on the extent of orthodontic tooth movement, and the number of osteoclasts were analyzed by independent sample t-test. Results: The results indicated that 2,7 and 14 days after force application there was no significant difference in orthodontic tooth movement between experimental and control groups (p>0.05). The number of osteoclasts were significantly lower in the experimental group 7 and 14 days after spring insertion (p<0.05). Conclusion: Pregnancy may decrease the amount of tooth movement in the linear phase but it is not statistically significant. The number of osteoclasts is significantly decreased during pregnancy

Image guidance and improved accuracy of external ventricular drain tip position particularly in patients with small ventricles.

OBJECTIVE External ventricular drain (EVD) insertion is one of the most common emergency neurosurgical procedures. EVDs are traditionally inserted freehand (FH) in an emergency setting, but often result in suboptimal positioning. Image-guided surgery (IGS) is selectively used to assist placement. However, the accuracy and practicality of IGS use is yet to be reported. In this study, the authors set out to assess if IGS is practical and improves the accuracy of EVD placement. METHODS Case notes and images obtained in patients who underwent frontal EVD placement were retrospectively reviewed. Ventriculomegaly was determined by the measurement of the Evans index. EVD location was classified as optimal (ipsilateral frontal horn) or suboptimal (any other location). Propensity score matching of the two groups (IGS vs FH) for the Evans index was performed. Data were analyzed for patient age, diagnosis, number of EVDs, and complications. Those without postoperative CT scans were excluded. RESULTS A total of 607 patients with 760 EVDs placed were identified; 331 met inclusion criteria. Of these, 287 were inserted FH, and 44 were placed with IGS; 60.6% of all unmatched FH EVDs were optimal compared with 75% of the IGS group (p = 0.067). The IGS group had a significantly smaller Evans index (p < 0.0001). Propensity score matching demonstrated improved optimal position in the IGS group when compared with the matched FH group (75% vs 43.2%, OR 4.6 [1.5-14.6]; p = 0.002). Patients with an Evans index of ≥ 0.36 derived less benefit (75% in IGS vs 66% in FH, p = 0.5), and those with an Evans index < 0.36 derived more benefit (75% in IGS vs 53% in FH, p = 0.024). The overall EVD complication rate was 36% in the FH group versus 18% in the IGS group (p = 0.056). Revision rates were higher in the FH group (p = 0.035), and the operative times were similar (p = 0.69). Long intracranial EVD catheters were associated with tip malposition irrespective of the group. CONCLUSIONS Image guidance is practical and improves the accuracy of EVD placement in patients with small ventricles; thus, it should be considered for these patients

The effect of oral contraceptives on orthodontic tooth movement in rat

Introduction: The purpose of this study was to investigate the effect of ethinyl estradiol/norgestrel ? used in some oral contraceptives- on orthodontic tooth movement in Wistar rats. Material and Methods: Forty eight female three-month old Wistar rats with an average weight of 250?25gr were divided into two experimental and control groups. One week prior to appliance insertion and during the appliance therapy period, 100 mcg/kg/day of ethinyl estradiol and 1mg/kg/days of norgestrel were administered to the experimental group by gavage; meanwhile the control group received an equivalent volume of Sodium Chloride 0.9 % (Saline). Maxillary central incisors were tipped distally by insertion of springs exerting 30g force. Two, seven and fourteen days after spring insertion animals were sacrificed. The mesioincisal distance between maxillary incisors were measured. Subsequently, histological sections were prepared for histomorphometric studies. Results: 14 days after force application the orthodontic tooth movement was significantly lower in the experimental group (p<0.05). The number of osteoclasts were significantly lower in the experimental group 2, 7 and 14 days after spring insertion (p<0.05). Conclusion: Ethinyl estradiol/norgestrel (oral contraceptives) can significantly decrease the amount of tooth movement in the linear phase

Computing stress intensity factors for curvilinear cracks

The use of the interaction integral to compute stress intensity factors around a crack tip requires selecting an auxiliary field and a material variation field. We formulate a family of these fields accounting for the curvilinear nature of cracks that, in conjunction with a discrete formulation of the interaction integral, yield optimally convergent stress intensity factors. We formulate three pairs of auxiliary and material variation fields chosen to yield a simple expression of the interaction integral for different classes of problems. The formulation accounts for crack face tractions and body forces. Distinct features of the fields are their ease of construction and implementation. The resulting stress intensity factors are observed converging at a rate that doubles the one of the stress field. We provide a sketch of the theoretical justification for the observed convergence rates, and discuss issues such as quadratures and domain approximations needed to attain such convergent behavior. Through two representative examples, a circular arc crack and a loaded power function crack, we illustrate the convergence rates of the computed stress intensity factors. The numerical results also show the independence of the method on the size of the domain of integration

Thermal analysis of a commercial plate fin heat exchanger with non-uniform inlet flow conditions

In studies using computational fluid dynamics software, very often a uniform air stream is applied as inlet boundary condition of a heat exchanger. In actual applications, however, the inlet flow conditions are not uniform. Therefore, the effect of non-uniformities on the thermal performance is characterized in a wind tunnel for a commercially available plate water/air heat exchanger. Three non-uniform flow conditions are investigated. The heat exchanger is 275 mm wide and 295 mm high. Three non-uniformities are created by placing a plate 10 cm upstream of the heat exchanger: the first one covers the right-hand side of the heat exchanger, the second one covers the top half of the heat exchanger and the last obstruction consists of a circular hole of 150 mm diameter in the middle of a plate. Only the circular obstruction has a significant influence on the heat transfer rate: the external convective resistance is up to 25% higher compared to the uniform case. The measurement results presented in this study can be used by other researchers to validate numerical simulations with non-uniform inlet conditions

Fibronectin rescues estrogen receptor α from lysosomal degradation in breast cancer cells

Estrogen receptor α (ERα) is expressed in tissues as diverse as brains and mammary glands. In breast cancer, ERα is a key regulator of tumor progression. Therefore, understanding what activates ERα is critical for cancer treatment in particular and cell biology in general. Using biochemical approaches and superresolution microscopy, we show that estrogen drives membrane ERα into endosomes in breast cancer cells and that its fate is determined by the presence of fibronectin (FN) in the extracellular matrix; it is trafficked to lysosomes in the absence of FN and avoids the lysosomal compartment in its presence. In this context, FN prolongs ERα half-life and strengthens its transcriptional activity. We show that ERα is associated with β1-integrin at the membrane, and this integrin follows the same endocytosis and subcellular trafficking pathway triggered by estrogen. Moreover, ERα+ vesicles are present within human breast tissues, and colocalization with β1-integrin is detected primarily in tumors. Our work unravels a key, clinically relevant mechanism of microenvironmental regulation of ERα signaling.Fil: Sampayo, Rocío Guadalupe. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Toscani, Andrés Martin. Universidad Nacional de Luján; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Rubashkin, Matthew G.. University of California; Estados UnidosFil: Thi, Kate. Lawrence Berkeley National Laboratory; Estados UnidosFil: Masullo, Luciano Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Violi, Ianina Lucila. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias "Elizabeth Jares Erijman"; ArgentinaFil: Lakins, Jonathon N.. University of California; Estados UnidosFil: Caceres, Alfredo Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Hines, William C.. Lawrence Berkeley National Laboratory; Estados UnidosFil: Coluccio Leskow, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad Nacional de Luján; ArgentinaFil: Stefani, Fernando Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Chialvo, Dante Renato. Universidad de Buenos Aires; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología. Centro Internacional de Estudios Avanzados; ArgentinaFil: Bissell, Mina J.. Lawrence Berkeley National Laboratory; Estados UnidosFil: Weaver, Valerie M.. University of California; Estados UnidosFil: Simian, Marina. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Oncología "Ángel H. Roffo"; Argentin

Abnormal white matter blood-oxygen-level-dependent signals in chronic mild traumatic brain injury

Concussion, or mild traumatic brain injury (mTBI), can cause persistent behavioral symptoms and cognitive impairment, but it is unclear if this condition is associated with detectable structural or functional brain changes. At two sites, chronic mTBI human subjects with persistent post-concussive symptoms (three months to five years after injury) and age- and education-matched healthy human control subjects underwent extensive neuropsychological and visual tracking eye movement tests. At one site, patients and controls also performed the visual tracking tasks while blood-oxygen-level-dependent (BOLD) signals were measured with functional magnetic resonance imaging. Although neither neuropsychological nor visual tracking measures distinguished patients from controls at the level of individual subjects, abnormal BOLD signals were reliably detected in patients. The most consistent changes were localized in white matter regions: anterior internal capsule and superior longitudinal fasciculus. In contrast, BOLD signals were normal in cortical regions, such as the frontal eye field and intraparietal sulcus, that mediate oculomotor and attention functions necessary for visual tracking. The abnormal BOLD signals accurately differentiated chronic mTBI patients from healthy controls at the single-subject level, although they did not correlate with symptoms or neuropsychological performance. We conclude that subjects with persistent post-concussive symptoms can be identified years after their TBI using fMRI and an eye movement task despite showing normal structural MRI and DTI

Temperature Controlled Stacked Board Cavity

This publication describes techniques and apparatuses that decrease the temperature variation in a cavity created by an interposer that stacks two or more boards inside a smartphone. When operating electrical components, heat generation is inevitable. A way to minimize temperature variation is by embracing and managing a safe rise in temperature in and/or around the electrical components inside the cavity of the interposer. A safe rise in temperature may be a temperature between +25°C and +85°C (e.g., +55°C). That way, when the smartphone shifts from an idle state to normal operation, the cavity of the interposer and the electrical components inside the cavity do not experience a large temperature variation—the cavity is pre-warmed. Less temperature variation enables the smartphone to use less complex software and lookup tables that are limited to one temperature (e.g., +55°C) instead of a wide range of temperatures, such as from -40°C to +85°C. Limiting temperature variation by keeping the cavity of the interposer above room temperature and below the maximum temperature offers consistent smartphone performance, better space utilization, and decreased manufacturing and/or operational cost