166 research outputs found
Chiral and deconfinement transitions in a magnetic background using the functional renormalization group with the Polyakov loop
We use the Polyakov loop coupled quark-meson model to approximate low energy
QCD and present results for the chiral and deconfinement transitions in the
presence of a constant magnetic background at finite temperature and
baryon chemical potential . We investigate effects of various gluoni
potentials on the deconfinement transition with and without a fermionic
backreaction at finite . Additionally we investigate the effect of the
Polyakov loop on the chiral phase transition, finding that magnetic catalysis
at low is present, but weakened by the Polyakov loop.Comment: 17 pages and 8 figs. v2: added ref
Inverse magnetic catalysis and regularization in the quark-meson model
Motivated by recent work on inverse magnetic catalysis at finite temperature,
we study the quark-meson model using both dimensional regularization and a
sharp cutoff. We calculate the critical temperature for the chiral transition
as a function of the Yukawa coupling in the mean-field approximation varying
the renormalization scale and the value of the ultraviolet cutoff. We show that
the results depend sensitively on how one treats the fermionic vacuum
fluctuations in the model and in particular on the regulator used. Finally, we
explore a -dependent transition temperature for the Polyakov loop potential
using the functional renormalization group. These results show that
even arbitrary freedom in the function does not allow for a decreasing
chiral transition temperature as a function of . This is in agreement with
previous mean-field calculations.Comment: 13 pages, 5 figure
Hemoperitoneum after spontaneous rupture of liver tumor: results of surgical treatment
Five cases of massive hemoperitoneum caused by spontaneous rupture of liver tumors, collected during a 27-year period, are reported. Four patients had a primary liver malignancy and one patient a liver cyst with hemangioma. Initial symptoms were obscure and hemoperitoneum was suspected pre-operatively in only one patient. At operation, a mean of 3100 ml of blood was found in the abdomen. Hemostatis was achieved by liver resection in four patients and by suture ligation in one. Two patients died during or shortly after operation. The three patients surviving the operation had primary liver cancer and lived for 6 months to 6.5 years. It is concluded that liver resection, whenever possible, is the treatment of choice and that pre-operative delay and mortality may be diminished by increased awareness of this condition
Reresection of Colorectal Liver Secondaries: A Preliminary Report
During a 4.5-year period, 5 patients underwent reresection of colorectal liver metastases. Two patients died of recurrent disease, 9-11 months after reresection. Three patients are alive, one without and two with recurrent disease, 15, 15 and 68 months after reresection. Although our results suggest that liver reresection may be meaningful in selected patients with colorectal liver metastases, further studies are necessary in order to define candidates for this procedure
Bile Peritonitis in Acute Cholecystitis
A review of all patients treated for acute cholecystitis (n = 5848) during an 18-year period (1969-1986) at two hospitals (one practising early surgery in patients with acute cholecystitis and the other not) disclosed that 104 (1.8%) had bile within the abdominal cavity at surgery; 71 with a visible perforation of the gallbladder and 33 without. The bile was infected in 82% of performed cultures (most commonly with Escherichia coli). Mortality was 7.7% (8/104 patients), being 20% (4/20) in the hospital practising delayed surgery and 5% (4/84) in the hospital practising early surgery (p less than 0.10). Infectious complications were responsible for the deaths by leading to multiple organ failure with pulmonary or renal insufficiency or gastro-intestinal bleeding. The timing of surgery was the only factor that had prognostic significance, i.e. the longer the hospital delay before surgery the higher the mortality, although elderly patients or patients with perforation tended to have a worse prognosis. In conclusion, the results of this study indicated that early surgery is important in patients with acute cholecystitis as a means of lowering mortality in bile peritonitis in this condition
Liver resection for intrahepatic stones
Intrahepatic stones are difficult to manage, especially when they are associated with bile duct stricture, cholangitis and destruction of liver parenchyma. Suggested modes of treatment include surgical bile duct exploration, endoscopic procedures, transhepatic cholangiolithotomy and liver resection. This paper reports 2 patients in whom liver resection was performed because of intrahepatic ductal stones, bile duct strictures and repeated episodes of cholangitis. Liver resection was uncomplicated and long-term results were satisfactory. Our results support the view that liver resection is indicated in rare instances of intrahepatic bile duct stones associated with bile duct strictures
Quantum back-reaction of the superpartners in a large-N supersymmetric hybrid model
We study the supersymmetric hybrid model near and after the end of inflation.
As usual, we reduce the model to a purely scalar hybrid model on the level of
the classical fields. But on the level of quantum fluctuations and their
backreaction we take into account all superpartners of the waterfall field in a
large-N approximation. The evolution after slow roll displays two phases with a
different characteristic behaviour of the classical and fluctuation fields. We
find that the fluctuations of the pseudoscalar superpartner are of particular
importance in the late time phase. The motion of the waterfall field towards
its classical expectation value is found to be very slow and suggests a rather
flat potential and a stochastic force.Comment: 37 pages 19 figure
An Inflationary Scenario in Intersecting Brane Models
We propose a new scenario for D-term inflation which appears quite
straightforwardly in the open string sector of intersecting brane models. We
take the inflaton to be a chiral field in a bifundamental representation of the
hidden sector and we argue that a sufficiently flat potential can be brane
engineered. This type of model generically predicts a near gaussian red
spectrum with negligible tensor modes. We note that this model can very
naturally generate a baryon asymmetry at the end of inflation via the recently
proposed hidden sector baryogenesis mechanism. We also discuss the possibility
that Majorana masses for the neutrinos can be simultaneously generated by the
tachyon condensation which ends inflation. Our proposed scenario is viable for
both high and low scale supersymmetry breaking.Comment: 30 pages, 2 figures; v2 references and comments adde
Ο-Conotoxin GVIA mimetics that bind and inhibit neuronal Cav2.2 ion channels
The neuronal voltage-gated N-type calcium channel (Cav2.2) is a validated target for the treatment of neuropathic pain. A small library of anthranilamide-derived ω-Conotoxin GVIA mimetics bearing the diphenylmethylpiperazine moiety were prepared and tested using three experimental measures of calcium channel blockade. These consisted of a 125I-ω-conotoxin GVIA displacement assay, a fluorescence-based calcium response assay with SH-SY5Y neuroblastoma cells, and a whole-cell patch clamp electrophysiology assay with HEK293 cells stably expressing human Cav2.2 channels. A subset of compounds were active in all three assays. This is the first time that compounds designed to be mimics of ω-conotoxin GVIA and found to be active in the 125I-ω-conotoxin GVIA displacement assay have also been shown to block functional ion channels in a dose-dependent manner
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