Development of a Langmuir probe array for radial potential profile measurement in the collisional merging formation FRC.

The radial electric field in a field-reversed configuration (FRC) plasma plays an important role in the global stability and confinement properties. Herein, we developed a new Langmuir probe array named "Skewered probe" employed in measuring the radial potential profile in the collisional merging formation of an FRC in the FAT-CM (FRC Amplification via Translation - Collisional Merging) device. Because an FRC has a strong toroidal flow, the skewered probe consists of alternately skewered ring electrodes and ceramic beads on a thin stainless-steel tube to neutralize the effect of plasma flow. The developed array has nine electrodes, one every 2 cm from r = 9-25 cm, and it measures the FRC boundary in the case when the radius of the excluded flux ranges from 10 to 20 cm. The skewered probe also has one additional electrode that measures the potential near the chamber wall as a reference for the other electrodes. The radial potential profile of the FRC formed by the collisional merging method in the FAT-CM device was measured using the probe, and the results showed that the region of negative potential gradually changed to a positive potential after merging the FRCs. It was also shown that a strong outward electric field is formed near the separatrix at n = 2 rotational instability.

Is lung resection appropriate for late octogenarians? Surgical outcomes of patients aged ≥ 80 years with lung cancer.

PURPOSE: This study aimed to determine the outcomes and prognostic factors associated with octogenarians who underwent pulmonary resection for lung cancer. METHODS/PATIENTS: From 2009 to 2018, 76 octogenarians underwent pulmonary surgery for lung cancer at the Kanazawa Medical University, Japan. They were divided into two groups (early and late octogenarians), and their clinicopathological characteristics and outcomes were investigated. Overall survival rates and recurrence-free survival rates were determined using Kaplan-Meier curves. Univariate and multivariate analyses were performed to identify prognostic factors. RESULTS: Limited surgery was performed more often in the late octogenarian group; however, most perioperative factors were not significantly different between the two groups. The 3-year overall survival and recurrence-free survival rates were 61.2% and 52.8%, respectively. The median observation period was 37.5 (8.9-112.3) months postoperatively. Kaplan-Meier curves showed that age ≥ 85 years (late octogenarian), smoking history, and squamous cell carcinoma on histology were associated with worse survival rates. Multivariate analysis identified age ≥ 85 years (late octogenarian) (p = 0.011) and cigarette smoking (p = 0.025) as unfavorable prognostic factors for overall survival and recurrence-free survival, respectively. CONCLUSIONS: Most octogenarians with an indication for surgery can tolerate pulmonary surgery. However, owing to the limitations of this retrospective, single-center study, future studies involving multiple-institutions are required to confirm our findings.

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime.

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes.

The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multicolor images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of [Formula: see text] years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu's surface supports partial dehydration due to internal heating of the asteroid's parent body.

Role of Mfa5 in Expression of Mfa1 Fimbriae in Porphyromonas gingivalis.

Fimbriae are protein-based filamentous appendages that protrude from the bacterial cell surface and facilitate host adhesion. Two types of fimbriae, FimA and Mfa1, of the periodontal pathogen Porphyromonas gingivalis are responsible for adherence to other bacteria and to host cells in the oral cavity. Both fimbrial forms are composed of 5 proteins, but there is limited information about their polymerization mechanisms. Here, the authors evaluated the function of Mfa5, one of the Mfa1 fimbrial accessory proteins. Using mfa5 gene disruption and complementation studies, the authors revealed that Mfa5 affects the incorporation of other accessory proteins, Mfa3 and Mfa4, into fibers and the expression of fimbriae on the cell surface. Mfa5 is predicted to have a C-terminal domain (CTD) that uses the type IX secretion system (T9SS), which is limited to this organism and related Bacteroidetes species, for translocation across the outer membrane. To determine the relationship between the putative Mfa5 CTD and the T9SS, mutants were constructed with in-frame deletion of the CTD and deletion of porU, a C-terminal signal peptidase linked to T9SS-mediated secretion. The ∆CTD-expressing strain presented a similar phenotype to the mfa5 disruption mutant with reduced expression of fimbriae lacking all accessory proteins. The ∆porU mutants and the ∆CTD-expressing strain showed intracellular accumulation of Mfa5. These results indicate that Mfa5 function requires T9SS-mediated translocation across the outer membrane, which is dependent on the CTD, and subsequent incorporation into fibers. These findings suggest the presence of a novel polymerization mechanism of the P. gingivalis fimbriae.

Reduced nasal growth after primary nasal repair combined with cleft lip surgery.

Nasal growth after cleft lip surgery with or without primary nasal repair was evaluated using lateral cephalograms. In 14 patients who underwent simultaneous nasal repair with primary cleft lip repair and 12 patients without simultaneous nasal repair, lateral cephalograms were obtained at 5 and 10 years of age. Lateral cephalograms of normal Japanese children were used as a control. At 5 years of age, there were significant differences in the nasal height and columellar angle among the three groups. Children without simultaneous nasal repair had shorter noses with more upward tilt of the columella compared with the controls, while children with simultaneous nasal repair had much shorter noses and more upward tilt than those without repair. At 10 years of age, the children without simultaneous nasal repair showed no differences from the control group, while those with simultaneous repair still had shorter noses and more upward tilt of the columella. These findings suggest that performing nasal repair at the same time as primary cleft lip surgery has an adverse influence on the subsequent growth of the nose.

Micromotors working in water through artificial aerobic metabolism.

Most catalytic micro/nanomotors that have been developed so far use hydrogen peroxide as fuel, while some use hydrazine. These fuels are difficult to apply because they can cause skin irritation, and often form and store disruptive bubbles. In this paper, we demonstrate a novel catalytic Pt micromotor that does not produce bubbles, and is driven by the oxidation of stable, non-toxic primary alcohols and aldehydes with dissolved oxygen. This use of organic oxidation mirrors living systems, and lends this new motor essentially the same characteristics, including decreased motility in low oxygen environments and the direct isothermal conversion of chemical energy into mechanical energy. Interestingly, the motility direction is reversed by replacing the reducing fuels with hydrogen peroxide. Therefore, these micromotors not only provide a novel system in nanotechnology, but also help in further revealing the underlining mechanisms of motility of living organisms.

A thermal control system for long-term survival of scientific instruments on lunar surface.

A thermal control system is being developed for scientific instruments placed on the lunar surface. This thermal control system, Lunar Mission Survival Module (MSM), was designed for scientific instruments that are planned to be operated for over a year in the future Japanese lunar landing mission SELENE-2. For the long-term operations, the lunar surface is a severe environment because the soil (regolith) temperature varies widely from nighttime -200 degC to daytime 100 degC approximately in which space electronics can hardly survive. The MSM has a tent of multi-layered insulators and performs a "regolith mound". Temperature of internal devices is less variable just like in the lunar underground layers. The insulators retain heat in the regolith soil in the daylight, and it can keep the device warm in the night. We conducted the concept design of the lunar survival module, and estimated its potential by a thermal mathematical model on the assumption of using a lunar seismometer designed for SELENE-2. Thermal vacuum tests were also conducted by using a thermal evaluation model in order to estimate the validity of some thermal parameters assumed in the computed thermal model. The numerical and experimental results indicated a sufficient survivability potential of the concept of our thermal control system.

13C-phenylalanine breath test detects altered phenylalanine kinetics in schizophrenia patients.

Phenylalanine is an essential amino acid required for the synthesis of catecholamines including dopamine. Altered levels of phenylalanine and its metabolites in blood and cerebrospinal fluid have been reported in schizophrenia patients. This study attempted to examine for the first time whether phenylalanine kinetics is altered in schizophrenia using L-[1-(13)C]phenylalanine breath test ((13)C-PBT). The subjects were 20 chronically medicated schizophrenia patients (DSM-IV) and the same number of age- and sex-matched controls. (13)C-phenylalanine (99 atom% (13)C; 100 mg) was administered orally and the breath (13)CO(2) /(12)CO(2) ratio was monitored for 120 min. The possible effect of antipsychotic medication (risperidone (RPD) or haloperidol (HPD) treatment for 21 days) on (13)C-PBT was examined in rats. Body weight (BW), age and diagnostic status were significant predictors of the area under the curve of the time course of Δ(13)CO(2) (‰) and the cumulative recovery rate (CRR) at 120 min. A repeated measures analysis of covariance controlled for age and BW revealed that the patterns of CRR change over time differed between the patients and controls and that Δ(13)CO(2) was lower in the patients than in the controls at all sampling time points during the 120 min test, with an overall significant difference between the two groups. Chronic administration of RPD or HPD had no significant effect on (13)C-PBT indices in rats. Our results suggest that (13)C-PBT is a novel laboratory test that can detect altered phenylalanine kinetics in chronic schizophrenia patients. Animal experiments suggest that the observed changes are unlikely to be attributable to antipsychotic medication.

Treatment of cranium bifidum occultum of the frontonasal region with a pericranial flap.

Cranium bifidum is a congenital anomaly caused by abnormal development of the cephalic neural tube. We report two cases of cranium bifidum occultum with defects of both the frontal bone and anterior cranial base accompanied by infection and enlargement of frontonasal dermoid cysts. Surgery successfully interrupted the communication between the intracranial space and nasal cavity by inserting a pericranial flap after removal of the dermoid cysts.

Remineralization and acid resistance of enamel lesions after chewing gum containing fluoride extracted from green tea.

BACKGROUND: The aim of this study was to evaluate enamel remineralization and the acquisition of acid resistance by using sugar-free chewing gum containing fluoride extracted from green tea. METHODS: Forty-five volunteers participated in a crossover, double-blind study and wore intraoral appliances with human demineralized enamel. Subjects chewed fluoride chewing gum (FCG: 50 µg fluoride) or placebo gum. Remineralization and acid resistance were evaluated using the mineral change value (ΔZ, in vol%·µm). Fluoride concentrations in saliva and remineralized enamel were analysed. RESULTS: The peak salivary fluoride concentration was 3.93 ± 1.28 ppm (mean ± SD). The elevated salivary fluoride concentration resulted in a higher fluoride concentration of 656 ± 95 ppm in the remineralized region versus 159 ± 26 ppm for placebo gum (p < 0.001). After remineralization, the ΔZ of the FCG group was higher than that of the placebo gum group. After an acid challenge, ΔZ of the FCG group was lower than the placebo gum group. Both ΔZ were statistically significant. CONCLUSIONS: FCG produced a superior level of remineralization and acid resistance, as compared to the placebo gum. The in situ results suggest that regular use of FCG is useful for preventing dental caries.

Pediatrician-recommended use of sports drinks and dental caries in 3-year-old children.

OBJECTIVES: To determine whether children advised by a pediatrician to take sports drinks consume them more frequently than do other children and whether these children have an increased risk of dental caries. METHODS: The subjects were 522 mother/child pairs who attended a dental checkup for 3-year-olds at one of ten community health centers in Nagasaki, Japan. Pearson's chi-square test was used to compare the prevalence of children with or without dental caries according to child-related variables. Multiple logistic regression was performed to assess the relationship between the presence of dental caries and child-related variables taken from a dental checkup and a questionnaire. RESULTS: A high frequency of sports drink consumption was strongly associated with dental caries in children. The highest proportion of mothers answered that they were advised by a pediatrician to give sports drinks to their children. However, these children consumed sports drinks significantly less frequently than did children who did so for reasons other than pediatrician recommendations. In addition, these children were significantly less likely to have dental caries than were children who consumed sports drinks for otherreasons. CONCLUSIONS: Pediatrician-recommended consumption of sports drinks does not lead to more frequent consumption of these beverages or to dental caries in 3-year-old children.

Effect of annealing in hydrogen atmosphere on carbon nanocap formation in surface decomposition of 6H-SiC(000-1).

We investigated the effect of annealing in a hydrogen atmosphere on carbon nanocap formation during decomposition of a 6H-SiC(000-1) surface. It was determined that native oxides were reduced to below the detection limit of X-ray photoelectron spectroscopy after 30 min of annealing at 1200 degrees C in a hydrogen atomosphere at 10(-3) Pa. In addition, we found that the homogeneity of carbon nanocap size was improved on the SiC surface, compared with a sample annealed in ultra-high vacuum. This technique will be useful in the fabrication of homogeneous carbon nanotube layers by surface decomposition of SiC.

Molecular typing and antibiotic susceptibility patterns of enteropathogenic and shigatoxin producing Escherichia coli isolated from food handlers in three areas of Kenya.

OBJECTIVES: To determine the aetiology, epidemiology and sanitary factors of carriage of enteropathogenic Escherichia coli (EPEC) and Shiga-toxin producing E. coli (STEC) in food-handlers working in tourist hotels in three popular tourist destinations in Kenya. DESIGN: Cross sectional laboratory based study. SETTING: Three tourist destinations of Nairobi, Malindi and Diani in Kenya. SUBJECTS: Food handlers who were working in hotels frequented by tourists in the three study sites. RESULTS: Overall, during the period of April 2003 to May 2004, a total of 1399 food handlers stool samples were collected and analysed. EPEC expressing the eaeA gene and STEC expressing the stx2 gene were detected in 11/1399 (0.8%) and 2/1399 (0.1%) of the study subjects respectively. The mean age of the subjects from whom EPEC and STEC were isolated was similar (32.6 years) to those from whom no EPEC and STEC were isolated (32.5 years). Prior use of antibiotics, water source and toilet types were not significantly associated with the isolation of EPEC and STEC (p>0.05). There were 11 resistance patterns with six isolates (6/13, 46.2%) showing multidrug resistance. High prevalence of resistance was observed to co-trimoxazole (55.6%), chloramphenicol (33.3%), ampicillin (22.2%) and tetracycline (22.2%). High concentrations of antibiotics were required to achieve MIC90 for tetracycline, (>64 mg ml(-1)) and ampicillin (>256 mg ml(-1)). Cluster analysis of the Pulse Field Gel Electrophoresis profiles revealed that the EPEC and STEC isolates belonged to two main genotypes with 11 distinct DNA fragment profiles. CONCLUSION: This is the first report in Africa on the isolation of STEC from food handlers working in tourist hotels. These food handlers who carry the STEC and EPEC could potentially infect tourists and other people through food or water contamination in the hotel settings and thus our findings are of great public health importance.

Early detection of white spot lesions with digital camera and remineralization therapy.

BACKGROUND: In this paper, the characteristics of the early stage of dental caries are discussed and the methods we used to treat the early stage of dental caries to increase the number of caries-free patients are presented. Studies from in vitro to in situ experiments and a clinical study were carried out to support clinical remineralization therapy. METHODS AND RESULTS: To clarify the effect of time for remineralization, the degree of remineralization was assessed at 2 days, 6 days, and 10 days after 2-day demineralization in 0.01 M/L lactic acid buffer (pH 4.0 at 37 degrees ). The remineralization solution contained 3.0 mM/L Ca, 1.8 mM/L P, and 3 ppm fluoride adjusted to pH 7.0. A 10-day continuous remineralization with a 3 ppm fluoride resulted in a high fluoride concentration. To evaluate mineral loss from sound tooth structure and white spot lesions, thin sections (about 90 microm) including white spots (WS) were prepared and exposed to oral conditions for 2 weeks continuously. The mineral loss from sound tooth structure was found to be twice that from WS. In another experiment during the remineralization period, enamel samples were immersed in three different bicarbonate solutions; 0.5, 5.0 and 50 mM/L for 30 minutes, two times per day. Both the bicarbonate and fluoride applied groups showed higher improvement in acid resistance and the amount of remaining mineral was almost two times higher than the controls (p < 0.01). In a clinical study we demonstrated remineralization in patients who followed professional mechanical tooth cleaning and fluoride prophylaxis paste. Using this regime, in patients with deciduous caries present at baseline, over 80 per cent of permanent teeth were caries free at the age of 12 years. In these studies the digital camera with CasMaTCH and an image analysis system showed several advantages for monitoring in de- and remineralization. CONCLUSIONS: White spot lesions, rather than intact tooth surfaces, can be mineralized through the daily clinical procedures described in this paper.

A complex polymorphic region in the brain-derived neurotrophic factor (BDNF) gene confers susceptibility to bipolar disorder and affects transcriptional activity.

Previous studies have suggested that genetic variations in the brain-derived neurotrophic factor (BDNF) gene may be associated with several neuropsychiatric diseases including bipolar disorder. The present study examined a microsatellite polymorphism located approximately 1.0 kb upstream of the translation initiation site of the BDNF gene for novel sequence variations, association with bipolar disorder, and effects on transcriptional activity. Detailed sequencing analysis revealed that this polymorphism is not a simple dinucleotide repeat, but it is highly polymorphic with a complex structure containing three types of dinucleotide repeats, insertion/deletion, and nucleotide substitutions that gives rise to a total of 23 novel allelic variants. We obtained evidence supporting the association between this polymorphic region (designated as BDNF-linked complex polymorphic region (BDNF-LCPR)) and bipolar disorder. One of the major alleles ('A1' allele) was significantly more common in patients than in controls (odds ratio 2.8, 95% confidential interval 1.5-5.3, P=0.001). Furthermore, a luciferase reporter gene assay in rat primary cultured neurons suggests that this risk allele (A1) has a lower-transcription activity, compared to the other alleles. Our results suggest that the BDNF-LCPR is a functional variation that confers susceptibility to bipolar disorder and affects transcriptional activity of the BDNF gene.

Acid resistance of enamel subsurface lesions remineralized by a sugar-free chewing gum containing casein phosphopeptide-amorphous calcium phosphate.

The aim of this clinical study was to investigate the acid resistance of enamel lesions remineralized in situ by a sugar-free chewing gum containing casein phosphopeptide-amorphous calcium phosphate nanocomplexes (CPP-ACP: Recaldent). The study utilized a double-blind, randomized, crossover design with two treatments: (i) sugar-free gum containing 18.8 mg of CPP-ACP, and (ii) sugar-free gum not containing CPP-ACP as control. Subjects wore removable palatal appliances with insets of human enamel containing demineralized subsurface lesions and chewed the gum for 20 min 4 times per day for 14 days. After each treatment the enamel slabs were removed and half of each lesion challenged with acid in vitro for 8 or 16 h. The level of remineralization was determined using microradiography. The gum containing CPP-ACP produced approximately twice the level of remineralization as the control sugar-free gum. The 8- and 16-hour acid challenge of the lesions remineralized with the control gum resulted in 65.4 and 88.0% reductions, respectively, of deposited mineral, while for the CPP-ACP-remineralized lesions the corresponding reductions were 30.5 and 41.8%. The acid challenge after in situ remineralization for both control and CPP-ACP-treated lesions resulted in demineralization underneath the remineralized zone, indicating that the remineralized mineral was more resistant to subsequent acid challenge. The results show that sugar-free gum containing CPP-ACP is superior to an equivalent gum not containing CPP-ACP in remineralization of enamel subsurface lesions in situ with mineral that is more resistant to subsequent acid challenge.

No association found between the type 1 sigma receptor gene polymorphisms and methamphetamine abuse in the Japanese population: a collaborative study by the Japanese Genetics Initiative for Drug Abuse.

It has been suggested that individual genetic factors are involved in susceptibility to drug dependence and the manifestation of drug-induced psychosis. The aim of this study was to examine the relation between methamphetamine abusers/psychosis and the type 1 sigma receptor gene polymorphisms. Subjects comprised 143 MAP abusers and 181 healthy controls. Two polymorphisms in the type 1 sigma receptor gene, GC-241-240TT and A61C (Gln2Pro), were examined in the present study. No significant differences were observed in either polymorphism between healthy controls and MAP abusers/psychosis. In the subgroup analyses, the rate of CC genotype of A61C tended to be higher in MAP patients who had experienced spontaneous relapse without MAP use than in those who had not (P = .06, OR = 3.02 95%CI = 0.92-9.92). However, the level of this significant trend did not remain after the Bonferroni's multiple correction. This study suggests that type 1 sigma receptor gene is unlikely to play a major role in substance abuse liability and/or the development of MAP psychosis.

Non-typhi salmonella in children with severe malaria.

OBJECTIVE: To determine the association between Plasmodium falciparum malaria and non-typhi Salmonella in children. DESIGN: Cross-sectional hospital based study. SETTING: Kilifi District Hospital (KDH) between January 1997 and June 2001. SUBJECTS: Children aged between three months to 123 months (mean age 28.28 months) and who had been admitted to the paediatric or High Dependency Research Ward (HDRW) of the KDH. METHODS: A total of 19, 118 blood cultures routinely obtained for all admissions and 1,820 clinically indicated stools samples were obtained from 9,147 children admitted with malaria. The specimens were cultured and antibiotic sensitivity done using standard laboratory procedures with stringent internal and external quality control in place. RESULTS: The total bacterial pathogens isolated from blood and stool were 1,395/19,118 (7.3%) and 342/1,820 (19%) respectively. Non-typhi salmonella consisted of 260/1,395 (18.6%) of the positive blood cultures and 92/324 (28.4%) of the stool cultures out of which a total of 101 NTS occurred in children with severe malaria. Out of the 9,147 malaria cases admitted, 101/9,147 (1.10%) had concomitant NTS infection. NTS with severe malaria as a proportion of all malaria admissions for the period varied between 0.8% and 1.5%. There was a significant association (p-value=0.032) between clinical outcome of death and female sex of the patient. The NTS isolates which occurred with severe malaria showed various levels of antibiotic resistance. They were resistant to ampicillin (35%), chloramphenicol (18%), gentamicin (22%), cefuroxime (29%), sulphamethoxazole-trimethoprim (39%), ciprofloxacin (3%), cefotaxime (14%), amoxycillin-clavulanic acid (26%) and tobramycin (18.0%). Multidrug resistance (MDR) was seen in 34 (33.6%) of the isolates. CONCLUSIONS: NTS and severe malaria occurring together are a problem in this area and that a large number of the isolates are MDR. An elaborate case-controlled study is required to elucidate the chain of events of both NTS and malaria parasite co-existence.

Geraniol dehydrogenase activity related to aroma formation in ginger (Zingiber officinale Roscoe).

Geranial is one of the potent odor compounds in fresh ginger. To clarify the generation of geranial in ginger, the alcohol dehydrogenase activity was measured in a crude enzymatic system of ginger. This enzyme solution was found to contain geraniol dehydrogenase (GeDH) specifically acting on geraniol as a substrate with NADP as a coenzyme. Geranial generation and GeDH activity were investigated for different maturity stages and storage periods of ginger. Both were at maximum levels from just after harvesting to initial storage. The GeDH activity subsequently dropped, and the generation of geranial also stopped. These results suggest that the GeDH activity in ginger is related to the generation of geranial.