106 research outputs found
On divergent 3-vertices in noncommutative SU(2)gauge theory
We analyze divergencies in 2-point and 3-point functions for noncommutative
-expanded SU(2)-gauge theory with massless fermions. We show that,
after field redefinition and renormalization of couplings, one divergent term
remains.Comment: 7 page
Non-renormalizability of noncommutative SU(2) gauge theory
We analyze the divergent part of the one-loop effective action for the
noncommutative SU(2) gauge theory coupled to the fermions in the fundamental
representation. We show that the divergencies in the 2-point and the 3-point
functions in the -linear order can be renormalized, while the
divergence in the 4-point fermionic function cannot.Comment: 15 pages, results presented at ESI 2d dilaton gravity worksho
Near-extremal and extremal quantum-corrected two-dimensional charged black holes
We consider charged black holes within dilaton gravity with
exponential-linear dependence of action coefficients on dilaton and minimal
coupling to quantum scalar fields. This includes, in particular, CGHS and RST
black holes in the uncharged limit. For non-extremal configuration quantum
correction to the total mass, Hawking temperature, electric potential and
metric are found explicitly and shown to obey the first generalized law. We
also demonstrate that quantum-corrected extremal black holes in these theories
do exist and correspond to the classically forbidden region of parameters in
the sense that the total mass ( is a charge). We show that in
the limit (where is the Hawking temperature) the mass and
geometry of non-extremal configuration go smoothly to those of the extremal
one, except from the narrow near-horizon region. In the vicinity of the horizon
the quantum-corrected geometry (however small quantum the coupling parameter
would be) of a non-extremal configuration tends to not the
quantum-corrected extremal one but to the special branch of solutions with the
constant dilaton (2D analog of the Bertotti-Robinson metric) instead.
Meanwhile, if exactly, the near-extremal configuration tends to the
extremal one. We also consider the dilaton theory which corresponds classically
to the spherically-symmetrical reduction from 4D case and show that for the
quantum-corrected extremal black hole .Comment: 25 pages. Typos corrected. To appear in Class. Quant. Gra
Effective Synergy of Sorafenib and Nutrient Shortage in Inducing Melanoma Cell Death through Energy Stress
Skin melanoma is one of the most aggressive and difficult-to-treat human malignancies, characterized by poor survival rates, thus requiring urgent novel therapeutic approaches. Although metabolic reprogramming has represented so far, a cancer hallmark, accumulating data indicate a high plasticity of cancer cells in modulating cellular metabolism to adapt to a heterogeneous and continuously changing microenvironment, suggesting a novel therapeutic approach for dietary manipulation in cancer therapy. To this aim, we exposed melanoma cells to combined nutrient-restriction/sorafenib. Results indicate that cell death was efficiently induced, with apoptosis representing the prominent feature. In contrast, autophagy was blocked in the final stage by this treatment, similarly to chloroquine, which also enhanced melanoma cell sensitization to combined treatment. Energy stress was evidenced by associated treatment with mitochondrial dysfunction and glycolysis impairment, suggesting metabolic stress determining melanoma cell death. A reduction of tumor growth after cycles of intermittent fasting together with sorafenib treatment was also observed in vivo, reinforcing that the nutrient shortage can potentiate anti-melanoma therapy. Our findings showed that the restriction of nutrients by intermittent fasting potentiates the effects of sorafenib due to the modulation of cellular metabolism, suggesting that it is possible to harness the energy of cancer cells for the treatment of melanoma
Physical, microscopic and chemical characterisation of industrial rye and wheat brans from the Nordic countries
Evaluation of sesamum gum as an excipient in matrix tablets
In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated
On the induced spawning and larval rearing of milkfish, Chanos chanos (Forskal)
Contribution No. 35 of the Aquaculture Department, SEAFDEC.A female milkfish, captured at sea, was injected with two hormonal injections of acetone-dried salmon pituitary powder and human chorionic gonadotropin, plus Vitamin B complex. It was stripped, and produced 128,000 ripe eggs with an average diameter of 1.15 mm. Fertilization rate was 38% following artificial fertilization with milt from an uninjected male. A total of 36,000 larvae hatched (74% of fertile eggs) after 26–32 h at 34 ‰ salinity and 27–32°C. The newly hatched larvae measured 3.4 mm in mean total length and possessed a large yolk sac. The mouth of the larvae opened about 54 h after hatching. The larvae were fed with fertilized oyster eggs, rotifers, copepods, brine shrimp, flour and prepared feed, together with Chlorella. A critical period was between the 4th and 6th days with mortality over 80%. The larvae started increasing in length by Day 8, and had the appearance of the wild fry by Day 11. On Day 13 a pigmentation pattern developed and the biggest larva measured 10.0 mm. By Day 18 the larvae measured 12.5 mm, and 14.5 mm by Day 21. A total of 2,859 fry was obtained; the highest larval survival rate obtained from different experimental groups was 46.8%
Relationships between proteasomes and RNA.
International audienceThe 20S proteasome (prosome) is a highly organized multi-protein complex with approximate molecular weight of about 700 kDa. Whilst the role of the proteasome in the processing and turnover of cellular proteins is becoming clearer, its relationship with RNA remains obscure. Over the last decade the possibility of association of proteasomes with specific RNAs or mRNPs have been particularly controversial. Proteasomes were reported to inhibit translation of viral mRNAs and to be tightly associated with RNase activity. It is possible that proteasomes are also involved in cellular RNA breakdown and RNA processing like prokaryotic RNase E
- …