41 research outputs found

    Double Q2Q^2-rescaling model and the nuclear effect of the parton distribution functions

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    In order to overcome the shortcoming of nonconservation of nuclear momentum existing in the original Q2Q^2-rescaling model(OQ2Q^2RM) and avoid introducing nuclear shadowing factor, we proposed a double Q2Q^2-rescaling model(DQ2Q^2RM) for the parton distributions of the bound nucleon. Using the experimental data of lepton-nucleus deep inelastic scattering(DIS) and the condition of the nuclear momentum conservation, the Q2Q^2-rescaling parameters of various partons for Sn, Fe, Ca and C nuclei are determined. The rescaling parameters of valence quark distributions are larger than unity and graduauly increases with atomic number A, on the contrary, the rescaling parameters of sea quark distributions and gluon distributions are smaller than unity, and slowly decreases with A. By using this model, the experimental data of the DIS process, the nuclear Drell-Yan process and J/ψJ/\psi photoproduction process are consistently and quite satisfactorily explained. Key words --- parton distribution functions, Nuclear effect, Double Q2Q^2-rescaling model.Comment: 15 pages, 4 figures (to be published in Z. Phys. C

    The potential of disproportionate growth of tricuspid valve after decompression of the right ventricle in patients with pulmonary atresia and intact ventricular septa

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    ObjectiveTricuspid valve size is the major determinant of outcomes for patients with pulmonary atresia with intact ventricular septum. Lack of right ventricle–pulmonary artery continuity is associated with poor tricuspid valve growth (decrement in Z-value). However, most reports did not show evidence for disproportionate growth of the tricuspid valve after establishment of right ventricle–pulmonary artery continuity.MethodsWe studied 40 patients with pulmonary atresia with intact ventricular septum who underwent initial right ventricular decompression for planned staged repair. The initial Z-value of the tricuspid valve diameter (Zt1) was obtained from the echocardiography-derived normal value. The late Z-value (Zt2) was measured before definitive repair or the last available Z-value, if definitive repair was not yet reached. The factors associated with the changes of Z-values (Zt2 − Zt1) were analyzed.ResultsThe mean initial tricuspid Z-value (Zt1) was −6.2 ± 3.5. After treatment (Zt2), the mean Z-value was −6.0 ± 3.4 (n = 34). Overall, the tricuspid Z-values did not change. Individually, the change in Z-value (Zt2 − Zt1) was larger than +2 in 11 (32%) patients and smaller than −2 in 6 (18%) patients. Increases in Z-value (Zt2 − Zt1) were significantly associated with right ventricular pressure/left ventricular pressure ratio measured after initial palliation (r = −0.54; P = .001) and the initial tricuspid valve Z-value (Zt1) (r = −0.40; P = .02).ConclusionsDisproportional growth of the tricuspid valve can occur, especially in patients with small tricuspid valves and lower right ventricular pressures after decompression. The findings support the possibility of neonates with small tricuspid valves undergoing biventricular repair after right ventricular decompression surgery

    Intracoronary Autologous Cardiac Progenitor Cell Transfer in Patients With Hypoplastic Left Heart Syndrome (TICAP) : A Prospective Phase 1 Controlled Trial

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    RATIONALE: Hypoplastic left heart syndrome (HLHS) remains a lethal congenital cardiac defect. Recent studies have suggested that intracoronary administration of autologous cardiosphere-derived cells (CDCs) may improve ventricular function. OBJECTIVE: The aim of this study was to test whether intracoronary delivery of CDCs is feasible and safe in patients with hypoplastic left heart syndrome. METHODS AND RESULTS: Between January 5, 2011, and January 16, 2012, 14 patients (1.8±1.5 years) were prospectively assigned to receive intracoronary infusion of autologous CDCs 33.4±8.1 days after staged procedures (n=7), followed by 7 controls with standard palliation alone. The primary end point was to assess the safety, and the secondary end point included the preliminary efficacy to verify the right ventricular ejection fraction improvements between baseline and 3 months. Manufacturing and intracoronary delivery of CDCs were feasible, and no serious adverse events were reported within the 18-month follow-up. Patients treated with CDCs showed right ventricular ejection fraction improvement from baseline to 3-month follow-up (46.9%±4.6% to 52.1%±2.4%; P=0.008). Compared with controls at 18 months, cardiac MRI analysis of CDC-treated patients showed a higher right ventricular ejection fraction (31.5%±6.8% versus 40.4%±7.6%; P=0.049), improved somatic growth (P=0.0005), reduced heart failure status (P=0.003), and lower incidence of coil occlusion for collaterals (P=0.007). CONCLUSIONS: Intracoronary infusion of autologous CDCs seems to be feasible and safe in children with hypoplastic left heart syndrome after staged surgery. Large phase 2 trials are warranted to examine the potential effects of cardiac function improvements and the long-term benefits of clinical outcomes

    The Biochemical and Cellular Basis for Nutraceutical Strategies to Attenuate Neurodegeneration in Parkinson’s Disease

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    Future therapeutic intervention that could effectively decelerate the rate of degeneration within the substantia nigra pars compacta (SNc) could add years of mobility and reduce morbidity associated with Parkinson’s disease (PD). Neurodegenerative decline associated with PD is distinguished by extensive damage to SNc dopaminergic (DAergic) neurons and decay of the striatal tract. While genetic mutations or environmental toxins can precipitate pathology, progressive degenerative succession involves a gradual decline in DA neurotransmission/synaptic uptake, impaired oxidative glucose consumption, a rise in striatal lactate and chronic inflammation. Nutraceuticals play a fundamental role in energy metabolism and signaling transduction pathways that control neurotransmission and inflammation. However, the use of nutritional supplements to slow the progression of PD has met with considerable challenge and has thus far proven unsuccessful. This review re-examines precipitating factors and insults involved in PD and how nutraceuticals can affect each of these biological targets. Discussed are disease dynamics (Sections 1 and 2) and natural substances, vitamins and minerals that could impact disease processes (Section 3). Topics include nutritional influences on α-synuclein aggregation, ubiquitin proteasome function, mTOR signaling/lysosomal-autophagy, energy failure, faulty catecholamine trafficking, DA oxidation, synthesis of toxic DA-quinones, o-semiquinones, benzothiazolines, hyperhomocyseinemia, methylation, inflammation and irreversible oxidation of neuromelanin. In summary, it is clear that future research will be required to consider the multi-faceted nature of this disease and re-examine how and why the use of nutritional multi-vitamin-mineral and plant-based combinations could be used to slow the progression of PD, if possible
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