Utjecaj negativnih iona na ionsko-zvučne solitarne valove u plazmi s dvije temperature elektrona

Ion-acoustic solitary waves in a drift negative ion plasma have been investigated for two-electron temperatures. Tagare and Reddy studied the effect of higher-order nonlinearity on ion-acoustic waves with cold positive and negative ions for isothermal and non-isothermal electrons using reductive perturbation technique. In this work, we study warm positive and negative ions with two-temperature isothermal electrons using the pseudopotential method. It is found that the concentration of negative ions, drift velocities, mass ratios, equal temperatures of ions (particular case) and presence of two groups of electrons and their ratios modify the profiles of the Sagdeev pseudopotential curves of the solitary waves in the plasma of the first- (φ1) and second-order (φ2) solitary-wave solutions.Istražujemo ionsko-zvučne solitarne valove u protječnoj negativnoj plazmi s dvije temperature elektrona. Tagare i Reddy su proučavali učinak nelinearnosti višeg reda na ionsko-zvučne valove s hladnim pozitivnim i negativnim ionima primjenom reduktivne metode smetnje. U ovom se radu proučavaju vrući pozitivni i negativni ioni metodom pseudopotencijala. Nalazimo da koncentracija negativnih iona, brzine protjecanja, omjeri masa, poseban slučaj jednakih temperatura iona i prisutnost dvije grupe elektrona i njihov omjer mijenjaju profile krivulja Sagdeevog pseudopotencijala solitarnih valova u plazmi za rješenja prvog (φ1) i drugog (φ2) reda

Smurf2 as a novel mitotic regulator: From the spindle assembly checkpoint to tumorigenesis

The execution of the mitotic program with high fidelity is dependent upon precise spatiotemporal regulation of posttranslational protein modifications. For example, the timely polyubiquitination of critical mitotic regulators by Anaphase Promoting Complex/Cyclosome (APC/C) is essential for the metaphase to anaphase transition and mitotic exit. The spindle assembly checkpoint prevents unscheduled activity of APC/C-Cdc20 in early mitosis, allowing bipolar attachment of kinetochores to mitotic spindle and facilitating equal segregation of sister chromatids. The critical effector of the spindle checkpoint, Mitotic arrest deficient 2 (Mad2), is recruited to unattached kinetochores forming a complex with other regulatory proteins to efficiently and cooperatively inhibit APC/C-Cdc20. A weakened and/or dysfunctional spindle checkpoint has been linked to the development of genomic instability in both cell culture and animal models, and evidence suggests that aberrant regulation of the spindle checkpoint plays a critical role in human carcinogenesis. Recent studies have illuminated a network of both degradative and non-degradative ubiquitination events that regulate the metaphase to anaphase transition and mitotic exit. Within this context, our recent work showed that the HECT (Homologous to E6-AP C-terminus)-family E3 ligase Smurf2 (Smad specific ubiquitin regulatory factor 2), known as a negative regulator of transforming growth factor-beta (TGF-β) signaling, is required for a functional spindle checkpoint by promoting the functional localization and stability of Mad2. Here we discuss putative models explaining the role of Smurf2 as a new regulator in the spindle checkpoint. The dynamic mitotic localization of Smurf2 to the centrosome and other critical mitotic structures provides implications about mitotic checkpoint control dependent on various ubiquitination events. Finally, deregulated Smurf2 activity may contribute to carcinogenesis by perturbed mitotic control

Spektroskopska mjerenja prijelaza D2 Rb u ovisnosti o temperaturi i snazi sa i bez Dopplerovog efekta

An external-cavity diode-laser spectrometer has been set up for high-resolution measurement of line shapes of the RbD2 transitions. Temperature-dependent fine-structure measurements are carried out in a free-running temperature condition by using frequency ramps for repetitive current tuning over a region of 17 GHz, encompassing all of the four Doppler broadened transitions of the two isotopes in an almost collision-free region. The Doppler broadened widths extracted from temperature-dependent line shapes, on least squares fitting to observed data, lead to an estimation of root-means-square velocities of vapour atoms under varying temperature conditions. Saturated-absorption spectroscopic measurements show complete resolution of the hyperfine Lamb dips and crossover resonance dips of one 87RbD2 transition. Data recorded from power-dependent measurement of one of unresolved 85RbD2 transitions are analyzed to obtain the saturation parameter and power broadening coefficient. The linewidths of different fully resolved Lamb dips of the hyperfine and crossover-resonance components are not the same, suggesting differences in their natural linewidths.Pomoću diodnog lasera s vanjskim rezonatorom načinili smo mjerenja oblika linija prijelaza D2 Rb. Mjerenja temperaturne ovisnosti fine strukture izveli smo u uvjetima slobodno promjenljive temperature, upotrebom frekventne rampe za ponavljanje struje, podešene za područje 17 GHz koje obuhvaća sva četiri Dopplerovim efektom proširena prijelaza dvaju izotopa Rb u uvjetima gotovo bez sudara. Širenje linija Dopplerovim efektom u ovisnosti o temperaturi, utvrđeno metodom najmanjih kvadrata, daje korijene iz srednjih kvadrata brzina atoma u parama. Spektroskopska mjerenja sa zasićenom apsorpcijom pokazuju potpuno razlučivanje hiperfinih Lambovih i preskočnih rezonantnih minimuma prijelaza D2 87Rb. Podatke iz mjerenja ovisnosti o snazi za nerazlučeni prijelaz D2 85Rb smo analizirali radi dobivanja parametara zasićenja i koeficijenta širenja sa snagom. Širine potpuno razlučenih linija hiperfinih Lambovih i preskočnih rezonantnih minimuma nisu jednake, što ukazuje na različitost njihovih prirodnih širina

Involvement of p38-betaTrCP-Tristetraprolin-TNFalpha axis in radiation pneumonitis

Early release of tumor necrosis factor-alpha (TNF-alpha) during radiotherapy of thoracic cancers plays an important role in radiation pneumonitis, whose inhibition may provide lung radioprotection. We previously reported radiation inactivates Tristetraprolin (TTP), a negative regulator of TNF-alpha synthesis, which correlated with increased TNF-alpha release. However, the molecular events involved in radiation-induced TTP inactivation remain unclear. To determine if eliminating Ttp in mice resulted in a phenotypic response to radiation, Ttp-null mice lungs were exposed to a single dose of 15 Gy, and TNF-alpha release and lung inflammation were analyzed at different time points post-irradiation. Ttp-/- mice with elevated (9.5+/-0.6 fold) basal TNF-alpha showed further increase (12.2+/-0.9 fold, p \u3c 0.02) in TNF-alpha release and acute lung inflammation within a week post-irradiation. Further studies using mouse lung macrophage (MH-S), human lung fibroblast (MRC-5), and exogenous human TTP overexpressing U2OS and HEK293 cells upon irradiation (a single dose of 4 Gy) promoted p38-mediated TTP phosphorylation at the serine 186 position, which primed it to be recognized by an ubiquitin ligase (E3), beta transducing repeat containing protein (beta-TrCP), to promote polyubiquitination-mediated proteasomal degradation. Consequently, a serine 186 to alanine (SA) mutant of TTP was resistant to radiation-induced degradation. Similarly, either a p38 kinase inhibitor (SB203580), or siRNA-mediated beta-TrCP knockdown, or overexpression of dominant negative Cullin1 mutants protected TTP from radiation-induced degradation. Consequently, SB203580 pretreatment blocked radiation-induced TNF-alpha release and radioprotected macrophages. Together, these data establish the involvement of the p38-betaTrCP-TTP-TNFalpha signaling axis in radiation-induced lung inflammation and identified p38 inhibition as a possible lung radioprotection strategy

Lowe Syndrome (Oculo-cerebro-renal Syndrome of Lowe): A Case Report from Eastern India

Lowe syndrome (the oculocerebrorenal syndrome of Lowe, OCRL) is a rare X-linked recessive metabolic disorder that primarily affects eyes, kidneys and brain. It is caused by the deficiency of enzyme phosphatidylinositol 4, 5-bisphosphate 5-phosphatase. The gene coding for this enzyme, OCRL1 and mutations in it are responsible to cause Lowe Syndrome. We report a 6 years old boy from Eastern India, with Lowe Syndrome. Diagnosis was suggested by typical features in the MRI of the brain along with other clinical feature and investigation

Immunogenic Modulations Induced by Prospective Anti-Malarial Herbal Extracts in Murine Model

Keeping in view the ever increasing problem of drug resistance and affordability of the antimalarial drugs by the poor mass, herbal medicines can become an important and alternative sustainable strategy for malaria treatment. Aqueous extracts of three Himalayan herbs― _Equisetum ravense_, _Artemisia vulgaris_ and _Centella asiatica_, with reported antimalarial property were screened for clinical efficacy against a local strain of _Plasmodium vivax_ antigen in murine model. _E. arvense_ extract was consistent in boosting phagocytic activity, nitric oxide generation, acid phosphatase and alkaline phosphatase activities in the peritoneal macrophages. The effectiveness of the rest herbals was discrete. A need for further detailed investigation to evaluate the clinical efficacy of these herbals seems essential