High-power laser experiment on developing supercritical shock propagating in homogeneously magnetized plasma of ambient gas origin

A developing supercritical collisionless shock propagating in a homogeneously magnetized plasma of ambient gas origin having higher uniformity than the previous experiments is formed by using high-power laser experiment. The ambient plasma is not contaminated by the plasma produced in the early time after the laser shot. While the observed developing shock does not have stationary downstream structure, it possesses some characteristics of a magnetized supercritical shock, which are supported by a one-dimensional full particle-in-cell simulation taking the effect of finite time of laser-target interaction into account.

High-power laser experiment forming a supercritical collisionless shock in a magnetized uniform plasma at rest

We present an experimental method to generate quasiperpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well magnetized, and it has uniform mass density. The plasma is pushed by laser-driven ablation aluminum (Al) plasma. Streaked optical pyrometry and spatially resolved laser collective Thomson scattering clarify structures of plasma density and temperatures, which are compared with one-dimensional particle-in-cell simulations. It is indicated that just after the laser irradiation, the Al plasma is magnetized by a self-generated Biermann battery field, and the plasma slaps the incident N plasma. The compressed external field in the N plasma reflects N ions, leading to counterstreaming magnetized N flows. Namely, we identify the edge of the reflected N ions. Such interacting plasmas form a magnetized collisionless shock.

Variables associated with the need for support in mental health check-up of new undergraduate students

AIMS

Frequent onset of several mental disorders starts around undergraduate age for university students. Mental health check-ups of the new students might help provide them with useful supports for improving their mental health. However, few studies have examined the validity of the check-up methods.

METHODS

Whether the scores of a five-factor personality inventory (NEO-FFI) at matriculation predict the needs of mental care and treatment during the first year of the undergraduate course were examined in 8287 new students of a university in Tokyo.

RESULTS

Logistic regression showed that high neuroticism, low extraversion and high openness of NEO-FFI, majoring in literature/philosophy/ psychology and living out of home were associated with need for mental care/treatment, in addition to the previous use of mental care services.

CONCLUSIONS

Personality inventory such as five-factor ones may be a useful supplemental tool for mental health check-up at matriculation to predict future needs of mental support in undergraduate university students. Students who smoke, live alone out of home and major in subjects such as philosophy might need to be more carefully supported than other students.

Agar gel precipitin line patterns and pathogenicity of infectious bursal disease viruses

Twenty-nine strains of infectious bursal disease virus could be classified into three groups by the agar gel precipitin line patterns using two representative base antigens of F539 and G691 strains. The precipitin line of the first group (16 strains including F539) did not fuse with that of G691 base antigen and spur was seen. The line of the second group (2 strains) did not fuse with those of both base antigens. The line of the third group (11 strains including G691) did not fuse with that of F539 base antigen. Every strain of the first group was highly pathogenic for chickens showing a mortality of 40% or more.

[The strategy against post-operative infection in the patients with esophageal cancer]

Post-operative infection with esophageal cancer patients was investigated. The subjects were 325 esophageal cancer patients. The most frequent infectious complication after the surgery was pneumonia, followed by anastomosis between the cervical esophagus and plastic stomach tube. The bacteria frequently found in infectious lesions were pseudomonas or staphylococcus. The more severe infection the patients had, the more gram negative bacteria were found. Bacterial examination during operation showed that more than 80% bacteria was gram negative. Since esophageal cancer patients had a low nutritional state, their immune function was impaired and infection was apt to occur post-operatively. Therefore, special nutritional care was indispensible, such as essential fatty acid, BCAA, and glutamine supplementation.

[Surgical infection and its backgrounds]

The backgrounds of surgical infection of esophageal cancer patients are studied for host factors (relation of nutrition and immune response) and parasite factors surgical parts which are easily contaminated, the differences of serum concentration with 3 methods of antibiotics administration, and the relations about the bacteria in mouth and upper esophagus in operation and bacteria which were found in the respiratory system after operation). The results are as follows. The preoperative nutritional support was effective to rapid recovery of cytological immune functions. But in the post-operative infected cases, immunological recovery delayed and they nutritionally needed BCAA, glutamine, and essential fatty acids. For the study of parasite factors, surgical wounds (neck, chest wall, abdominal wall) were more easily contaminated than other parts except digestive tract. Continuous administration of antibiotics, 1g/hr x 4 was most excessive in three methods. The bacteria in the mouth and upper esophagus in operation and those in airway after operation, were not correlated. Furthermore, antibiotics-resistant bacteria which were Pseudomonas, MRSA were found in the airway. These results indicate that nutritional support is important for the host defense system and antibiotics should be administered considering each operative process. And about the postoperative respiratory infection, protection of hospital infection is important.

Collision of malignant lymphoma and multiple early adenocarcinomas of the stomach

An unusual case of coexisting malignant lymphoma and adenocarcinoma of the stomach is described. A 61-year-old man with weight loss, malaise, and tarry stool demonstrated diffuse lymphoma, large-cell type, and two early gastric carcinomas. Each of the two early carcinomas collided with malignant lymphoma, respectively. Two histologically different tumors were precisely diagnosed preoperatively in this case. Frequent endoscopy with biopsies from various sites of the lesion is important in achieving a correct diagnosis.