Cosmic string in Abelian-Higgs model with enhanced symmetry - Implication to the axion domain-wall problem.

In our previous work, we found new types of the cosmic string solutions in the Abelian-Higgs model with an enhanced U(1) global symmetry. We dubbed those solutions as the compensated/uncompensated strings. The compensated string is similar to the conventional cosmic string in the Abrikosov-Nielsen-Olesen (ANO) string, around which only the would-be Nambu-Goldstone (NG) boson winds. Around the uncompensated string, on the other hand, the physical NG boson also winds, where the physical NG boson is associated with the spontaneous breaking of the enhanced symmetry. Our previous simulation in the 2+1 dimensional spacetime confirmed that both the compensated/uncompensated strings are formed at the phase transition of the symmetry breaking. Non-trivial winding of the physical NG boson around the strings potentially causes the so-called axion domain- wall problem when the model is applied to the axion model. In this paper, we perform simulation in the 3+1 dimensional spacetime to discuss the fate of the uncompensated strings. We observe that the evolution of the string-network is highly complicated in the 3+1 dimensional simulation compared with that seen in the previous simulation. Despite such complications, we find that the number of the uncompensated strings which could cause can be highly suppressed at late times. Our observation suggests that the present setup can be applied to the axion model without suffering from the axion domain-wall problem.

Testing the Seesaw Mechanism and Leptogenesis with Gravitational Waves.

We present the possibility that the seesaw mechanism with thermal leptogenesis can be tested using the stochastic gravitational background. Achieving neutrino masses consistent with atmospheric and solar neutrino data, while avoiding nonperturbative couplings, requires right handed neutrinos lighter than the typical scale of grand unification. This scale separation suggests a symmetry protecting the right-handed neutrinos from getting a mass. Thermal leptogenesis would then require that such a symmetry be broken below the reheating temperature. We enumerate all such possible symmetries consistent with these minimal assumptions and their corresponding defects, finding that in many cases, gravitational waves from the network of cosmic strings should be detectable. Estimating the predicted gravitational wave background, we find that future space-borne missions could probe the entire range relevant for thermal leptogenesis.

Esophageal transit scintigraphy and structured questionnaire in patients with systemic sclerosis with endoscopically proven reflux esophagitis.

OBJECTIVES: Esophageal complications are common in patients with systemic sclerosis (SSc). The relationship between gastroesophageal reflux (GER) symptoms and dysmotility was examined in endoscopically confirmed patients suspected of having reflux esophagitis. METHODS: A total of 32 patients with limited and diffuse type SSc (lSSc, dSSc) were examined based on a structured questionnaire score (QS) of GER symptoms, retention fraction of esophageal scintigraphy at 90 s (R(90)) and gastric emptying time. RESULTS: The QS was significantly higher in the reflux esophagitis group than in the non-esophagitis group (5.4 +/- 3.5, 1.4 +/- 2.9, P = 0.003). When the non-esophagitis group was further divided into lSSc and dSSc groups, R(90) was higher in the reflux esophagitis group (31 +/- 18%) and the non-esophagitis group with dSSc (34 +/- 32%) than in the non-esophagitis group with lSSc (8 +/- 3%, P = 0.02). Both high R(90) >or= 15% and QS >or= 4 indicated reflux esophagitis. Conversely, both normal R(90) and QS indicated no reflux esophagitis. CONCLUSION: A combination of esophageal scintigraphy and structured questionnaire demonstrated different aspects of esophageal dysfunction, namely dysmotility and GER. Patients with high QS and dysmotility may be indicated for further evaluation including endoscopic examination and medical treatment.

Intraperitoneal radioimmunotherapy to treat the early phase of peritoneal dissemination of human colon cancer cells in a murine model.

BACKGROUND AND AIM: In patients with a high risk of peritoneal dissemination of colon cancer, a treatment adjuvant to surgical resection would improve their prognosis. We aimed to determine whether radioimmunotherapy employing radiolabelled monoclonal antibody would work in this situation. METHODS: A murine model of peritoneal dissemination was established in female Balb/c nu/nu mice by intraperitoneal injection of LS180 human colon cancer cells. Radioimmunotherapy with 7.4 MBq of a murine IgG1, anti-colorectal A7 monoclonal antibody, radiolabelled with (131)I by the chloramine-T method was conducted intraperitoneally on days 0, 3, 7 and 14 after cell inoculation, respectively. RESULTS: Radioimmunotherapy at any timing improved survival of mice as compared with those of non-treated mice and mice treated with a daily dose of 30 mg x kg(-1) of 5-fluorouracil for 4 consecutive days. The best improvement was obtained when radioimmunotherapy was conducted on day 0. CONCLUSION: These results indicate that intraperitoneal radioimmunotherapy may effectively kill colon cancer cells disseminated in the peritoneal cavity before formation of tumours and, therefore, may work as an adjuvant treatment to prevent peritoneal metastasis of colon cancer.

[A case of tetanus showing limited mobility of the bilateral vocal cords].

Patients with tetanus complaining of common signs such as lockjaw, voice disturbance, and difficulty in swallowing, etc, should never be forgotten. A 71-year old woman complained of dyspnea and difficulty in swallowing. She had lockjaw with tongue bite soon after a tracheostomy, and she was diagnosed as having tetanus. She showed the redundant gag reflex even to a slight stimulus and limited mobility of bilateral vocal cords, which improved following intravenous administration of diazepam. This case suggests that the mobility of the vocal cords and the movement of the larynx could be limited in tetanus because even a slight stimulus caused a strong gag reflex, resulting in dyspnea or difficulty in swallowing.