Search for a new gauge boson in the A′A' Experiment (APEX)

We present a search at Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling $\alpha'$ to electrons. Such a particle $A'$ can be produced in electron-nucleus fixed-target scattering and then decay to an $e^+e^-$ pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175--250 MeV, found no evidence for an $A'\to e^+e^-$ reaction, and set an upper limit of $\alpha'/\alpha \simeq 10^{-6}$. Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.Comment: 5 pages, 5 figures, references adde

JLab Measurement of the 4^4He Charge Form Factor at Large Momentum Transfers

The charge form factor of ^4He has been extracted in the range 29 fm$^{-2}$ $\le Q^2 \le 77$ fm$^{-2}$ from elastic electron scattering, detecting $^4$He nuclei and electrons in coincidence with the High Resolution Spectrometers of the Hall A Facility of Jefferson Lab. The results are in qualitative agreement with realistic meson-nucleon theoretical calculations. The data have uncovered a second diffraction minimum, which was predicted in the $Q^2$ range of this experiment, and rule out conclusively long-standing predictions of dimensional scaling of high-energy amplitudes using quark counting.Comment: 4 pages, 2 figure

Возможности специфических иммунологических тестов у пациентов с туберкулезом в сочетании с ВИЧ-инфекцией

The objective of the study: to study the possibilities of skin tests with tuberculosis recombinant allergen (TRA) in the diagnosis of tuberculosis in HIV-positive patients in the region with a high prevalence of tuberculosis.Subjects and Methods. Medical files of 85 patients were retrospectively analyzed, all the patients suffered from TB/HIV coinfection and underwent the skin test with TRA.Results. The skin test with TRA was found to be significantly valuable for the diagnosis of tuberculosis in patients with TB/HIV coinfection. The correlation between the intensity of response to the TRA test and CD4+ count was detected (p = 0.011). The lowest values were observed for CD4+ counts below 100 cells/μL. The direct correlation between the intensity of response to TRA and the stage of HIV infection was proved. No effect of the form of tuberculosis, the phase of the tuberculosis disease, or drug sensitivity on the intensity of response to TRA was found. Among tuberculosis patients with bacterial excretion (n = 48), 68.8% of patients responded positively to the TRA test, and in those with no bacterial excretion, the positive reaction was observed in 81.1%.Цель исследования: изучить возможности кожной пробы с аллергеном туберкулезным рекомбинантным (АТР) в диагностике туберкулеза у ВИЧ-позитивных пациентов на территории с высокой распространенностью туберкулеза.Материалы и методы. Проведен ретроспективный анализ медицинских карт 85 пациентов с туберкулезом и ВИЧ-инфекцией, которым выполнена кожная проба с АТР.Результаты. Установлена значительная диагностическая ценность пробы с АТР в постановке диагноза туберкулеза у пациентов с сочетанием туберкулеза и ВИЧ-инфекции. Выявлена зависимость выраженности реакций на пробу с АТР от количества CD4+-лимфоцитов (p = 0,011). Наименьшие значения отмечены при количестве CD4+-лимфоцитов до 100 кл/мкл. Доказана прямая корреляционная связь выраженности реакций на АТР от стадии ВИЧ-инфекции. Влияние формы туберкулеза, фазы туберкулезного процесса и лекарственной чувствительности микобактерий туберкулеза, выделяемых пациентами, на выраженность реакций на АТР не установлено. Среди пациентов с туберкулезом и наличием бактериовыделения (n = 48) положительный результат пробы с АТР получен у 68,8% пациентов, а при отсутствии бактериовыделения ‒ у 81,1%

JLab Measurements of the 3He Form Factors at Large Momentum Transfers

The charge and magnetic form factors, FC and FM, of 3He have been extracted in the kinematic range 25 fm-2 < Q2 < 61 fm-2 from elastic electron scattering by detecting 3He recoil nuclei and electrons in coincidence with the High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements are indicative of a second diffraction minimum for the magnetic form factor, which was predicted in the Q2 range of this experiment, and of a continuing diffractive structure for the charge form factor. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the three-body nuclear problem

Measurement of the 12C(e,e'p)11B Two-Body Breakup Reaction at High Missing Momentum Values

The five-fold differential cross section for the 12C(e,e'p)11B reaction was determined over a missing momentum range of 200-400 MeV/c, in a kinematics regime with Bjorken x > 1 and Q2 = 2.0 (GeV/c)2. A comparison of the results and theoretical models and previous lower missing momentum data is shown. The theoretical calculations agree well with the data up to a missing momentum value of 325 MeV/c and then diverge for larger missing momenta. The extracted distorted momentum distribution is shown to be consistent with previous data and extends the range of available data up to 400 MeV/c.Comment: 12 pages, 1 table and 3 figures for submission to Journal Physics

JLab Measurements of the He-3 Form Factors at Large Momentum Transfers

The charge and magnetic form factors, F-C and F-M, respectively, of He-3 are extracted in the kinematic range 25 fm(-2) \u3c= Q(2) \u3c= 61 fm(-2) from elastic electron scattering by detecting He-3 recoil nuclei and scattered electrons in coincidence with the two High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements find evidence for the existence of a second diffraction minimum for the magnetic form factor at Q(2) = 49.3 fm(-2) and for the charge form factor at Q(2) = 62.0 fm(-2). Both minima are predicted to exist in the Q(2) range accessible by this Jefferson Lab experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the three-body nuclear problem

Carnitine reduces the lipoperoxidative damage of the membrane and apoptosis after induction of cell stress in experimental glaucoma

The pathological damage caused by glaucoma is associated to a high intraocular pressure. The ocular hypertone is most likely due to a defective efflux of aqueous humor from the anterior chamber of the eye. Ocular hypertension causes apoptotic death of retinal ganglion cells and overexpression of molecular markers typical of cell stress response and apoptosis. In this work, we report on the neuroprotective, antiapoptotic and antioxidant action of a natural substance, -carnitine. This compound is known for its ability to improve the mitochondrial performance. We analyze a number of cellular and molecular markers, typical of ocular hypertension and, in general, of the cell stress response. In particular, -carnitine reduces the expression of glial fibrillary acidic protein, inducible nitric oxide synthase, ubiquitin and caspase 3 typical markers of cell stress. In addition, the morphological analysis of the optic nerve evidenced a reduction of the pathological excavation of the optic disk. This experimental hypertone protocol induces a severe lipoperoxidation, which is significantly reduced by -carnitine. The overall interpretation is that mortality of the retinal cells is due to membrane damage

Metabolic constituents of grapevine and grape-derived products

The numerous uses of the grapevine fruit, especially for wine and beverages, have made it one of the most important plants worldwide. The phytochemistry of grapevine is rich in a wide range of compounds. Many of them are renowned for their numerous medicinal uses. The production of grapevine metabolites is highly conditioned by many factors like environment or pathogen attack. Some grapevine phytoalexins have gained a great deal of attention due to their antimicrobial activities, being also involved in the induction of resistance in grapevine against those pathogens. Meanwhile grapevine biotechnology is still evolving, thanks to the technological advance of modern science, and biotechnologists are making huge efforts to produce grapevine cultivars of desired characteristics. In this paper, important metabolites from grapevine and grape derived products like wine will be reviewed with their health promoting effects and their role against certain stress factors in grapevine physiology