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The dynamics of aggregation of tungstic acid was investigated as a function of time, using static and dynamic light scattering. Two types of kinetic behaviors were observed depending on the magnitude of the system parameter: One is the power-law growth and the other the exponential growth. At an intermediate value of the system parameter, the crossover from the power-law behavior to the exponential one was also observed. However, none of the aggregation kinetics observed had the characteristic rates: Those were directly controlled by an amount of hydrogen chloride added. Thus the universality in aggregation may not hold for the present colloidal system. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We investigate the rearrangement of the director in thin films of nematic liquid crystals caused by tightly focusing circularly polarized laser beams. We find either target or spiral patterns, depending on the topology of the director configuration at the position of the beam focus. The induced rearrangements of the director are governed by the viscosity of the media, the handedness of circular polarization, and the irradiation power of the laser. Experimental observations are interpreted using a model derived from nematic continuum theory. [ABSTRACT FROM AUTHOR]

A liquid crystalline physical gel has been prepared from the mixture of a nematic liquid crystal and a low molecular mass gelling agent containing a hydrogen-bonding moiety. The newly synthesized liquid crystalline compound exhibited photochromism in the crystalline solid phase. Although photochromism was not observed in the nematic gel state of the mixture, the lifetime of photochromism in the solid phase became longer, compared with that of a single liquid crystalline compound. Some Raman bands of the mixture showed a marked change in both intensity and frequency through the phase transitions. These bands have been assigned to the vibrational modes related to the core part of molecule. [ABSTRACT FROM AUTHOR]

In this study, we examined the effects of doping chlorine (Cl) into crystalline selenium (c-Se) on diminishing the tellurium-diffusion-induced shallow acceptor states associated with the dangling bonds that appear at the ends of Se chains by theoretical analysis with the first-principles calculations. In this model, the negatively charged dangling bonds can be neutralized by inserting monovalent Cl atoms. Furthermore, the defect termination by doping Cl into fabricated Se thin films was experimentally demonstrated. Low-temperature cathodoluminescence measurements were implemented to show that acceptor-related emissions from the c-Se films were significantly decreased by Cl termination of the dangling bonds, experimentally confirming the results of the simulations. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate the avalanche multiplication phenomenon in a crystalline-selenium (c-Se)-based heterojunction photodiode. The carrier injection from an external electrode, which is considered to be the major factor contributing to dark current at a high electric field, was significantly decreased by employing a thin n-type Ga2O3 layer with a high hole-injection barrier. The fabricated Ga2O3/c-Se diode exhibited extremely high external quantum efficiency of over 100% in the short-wavelength region at a relatively low reverse-bias voltage of ~20 V. Furthermore, Sn-doping of the Ga2O3 layer increases the carrier concentration; hence, the resulting device has a lower threshold voltage for avalanche multiplication. [ABSTRACT FROM AUTHOR]

A newly developed quantitative near-infrared spectroscopy (NIRS) system was used to measure changes in cortical hemoglobin oxygenation during the Verbal Fluency Task in 32 healthy controls, 15 subjects with mild cognitive impairment (MCI), and 15 patients with Alzheimer's disease (AD). The amplitude of changes in the waveform, which was quantitatively calculated by a signal processing method, was significantly lower in the frontal, and the bilateral parietal areas in the AD group, whereas that in the MCI group was significantly lower only in the right parietal area. The NIRS system may be a potential tool for the primary screening of AD. [ABSTRACT FROM AUTHOR]

Background: We assessed the radiographic characteristics of early colorectal carcinomas with submucosal invasion (CCSI) with the use of double-contrast images.Methods: From 1989 to 1997, 193 patients with 196 CCSI lesions underwent double-contrast barium enema examinations. Three gastrointestinal radiologists retrospectively reviewed the radiographic characteristics of the lesions and classified them as protruding and depressed types by consensus. Further, subclassifying the protruding into lobular and smooth types was accomplished on the basis of surface structure. Each type was compared with pathologic findings of resected specimens.Results: The incidence of the protruding type was 98.0%, and that of the depressed type was only 2.0%. The proportion of smooth lesions was 49.0% for the protruding type; these had a mean diameter of 17.9 mm, which was significantly smaller than the 23.1 mm mean observed for lobular lesions (p < 0.01). Of the smooth lesions, 44.7% demonstrated massive invasion, whereas 91.8% of lobular lesions exhibited only slight or moderate invasion into the submucosa (p < 0.01). The extent of invasion of the smooth lesions was greater than that for their lobular counterparts in terms of venous and lymph node involvement.Conclusion: Almost all CCSIs could be identified radiologically as protruding lesions; these had a smooth rather than a lobulated surface and demonstrated greater malignancy, despite the smaller size. It is clinically important to discriminate these from other polypoid lesions in establishing patient treatment. Double-contrast imaging is useful for evaluation of the surface characteristics of CCSIs in barium enema studies. [ABSTRACT FROM AUTHOR]

Background: We assessed the radiographic characteristics of early colorectal carcinomas with submucosal invasion (CCSI) with the use of double-contrast images. Methods: From 1989 to 1997, 193 patients with 196 CCSI lesions underwent double-contrast barium enema examinations. Three gastrointestinal radiologists retrospectively reviewed the radiographic characteristics of the lesions and classified them as protruding and depressed types by consensus. Further, subclassifying the protruding into lobular and smooth types was accomplished on the basis of surface structure. Each type was compared with pathologic findings of resected specimens. Results: The incidence of the protruding type was 98.0%, and that of the depressed type was only 2.0%. The proportion of smooth lesions was 49.0% for the protruding type; these had a mean diameter of 17.9 mm, which was significantly smaller than the 23.1 mm mean observed for lobular lesions (p < 0.01). Of the smooth lesions, 44.7% demonstrated massive invasion, whereas 91.8% of lobular lesions exhibited only slight or moderate invasion into the submucosa (p < 0.01). The extent of invasion of the smooth lesions was greater than that for their lobular counterparts in terms of venous and lymph node involvement. Conclusion: Almost all CCSIs could be identified radiologically as protruding lesions; these had a smooth rather than a lobulated surface and demonstrated greater malignancy, despite the smaller size. It is clinically important to discriminate these from other polypoid lesions in establishing patient treatment. Double-contrast imaging is useful for evaluation of the surface characteristics of CCSIs in barium enema studies. [ABSTRACT FROM AUTHOR]

The kinetics of the photodarkening effect has been studied experimentally for amorphous selenium (a-Se) layers at room temperature and at an elevated temperature (35 °C) close to the glass transition. By switching an intense pumping light on and off with a period of 100 s, we have studied the kinetics of both the buildup of photodarkening and its relaxation (recovery). It was found that at 35 °C, only a reversible component of photodarkening has been observed. This result has been interpreted within the framework of a phenomenological model assuming that photodarkening is caused by light-induced transitions of structural units from their ground states into metastable states. Our estimate for the energy barrier EB between these states obtained for the photodarkening process (EB∼0.8 eV) coincides with that obtained from the analysis of the relaxation process. At room temperature, an irreversible component of photodarkening has been observed along with the reversible one. The energy barrier responsible for the relaxation of the reversible component at room temperature appears the same as at 35 °C. This suggests that the energy barrier identified represents a fundamental feature of the photoinduced structural metastability in amorphous selenium. [ABSTRACT FROM AUTHOR]

Noble gases dissolved in groundwater have been used to evaluate characteristics such as origin, residence time and recharge temperature. Although obtaining samples without degassing is highly desired, in certain cases, degassing during sampling is unavoidable. This study investigated the degassing behavior of noble gases during sampling and evaluated the correction methods that can be applied. Groundwater samples were obtained from an underground laboratory and a deep borehole. The amount of exsolved gas was estimated by comparing pressurized and non-pressurized samples. Henry's model, which assumes equilibrium between gas and water, and a diffusion model were applied to the results. In addition, the compositions of gases extracted into an evacuated vessel or hollow fiber contactor were also compared with those of pressurized groundwater samples. The results indicated that significant degassing occurred in unpressurized samples, but equilibrium was achieved between gas and water when the total dissolved gas pressure (TDGP) was relatively small (up to 4.2 atm). Therefore, the d' Ne value, defined as the difference between the Ne concentration of air-saturated water and a sample normalized by the Ne concentration of air-saturated water, could be used in Henry's model to correct exsolution. However, inclusion of the effects of excess air and contamination is problematic. However, when TDGP was high (32 atm in this study), the degassing behavior completely changed and could not be predicted by Henry's model. During extraction of noble gases using an evacuated vessel and hollow fiber contactor, degassing was observed to take place following the diffusion model. As a result, fractionation between Ne vs. Kr and Xe was significant. Thus, although we could extract dissolved Ne with a high recovery ratio (over 0.85), the ratios of Kr/Ne and Xe/Ne were found to be significantly smaller than those in groundwater. The gases extracted by an evacuated vessel or hollow fiber contactor appeared to be applicable only for evaluating He/Ne. • Degassing behavior of noble gases was investigated during sampling groundwater. • Exsolved gas and dissolved gas were found to maintain equilibrium state. • Degassing behavior did not follow Henry's model if TDGP is large. [ABSTRACT FROM AUTHOR]

Smoking and alcohol are important modifiable risk factors for human cancers. However, few epidemiological studies have investigated their association with the risk of myelodysplastic syndromes ( MDS). Here, we investigated the association of smoking and alcohol consumption and the risk of MDS in a large-scale population-based cohort study in Japan. We included 95 510 Japanese subjects (45 451 men and 50 059 women; age 40-69 years at baseline) and identified 70 MDS cases (50 men and 20 women) during 18·3 years of follow-up. Hazard ratios ( HRs) and 95% confidence intervals (95% CI) were estimated using a Cox regression model adjusted for potential confounders. Smoking was marginally associated with an increased risk of MDS among men, with a HR for current smokers relative to never smokers of 2·11 (95% CI: 0·91-4·89). In contrast, alcohol consumption was associated with a dose-dependent decrease in the risk of MDS among men (nondrinkers: reference, occasional drinkers: HR = 0·48, 0·16-1·41; 0-299 g/week: HR = 0·37, 0·19-0·73; ≥300 g/week: HR = 0·49, 0·22-1·08, P for trend = 0·010). This study showed that alcohol has a significant protective effect on the risk of MDS. In addition, this study might indicate that smoking increases the risk of MDS among Japanese population, as it does in Western populations. [ABSTRACT FROM AUTHOR]

Objective To investigate the association between serum total cholesterol ( TC) and suicide using a large general population cohort with long follow-up times. Method Analyses included 16 341 men and 28 905 women aged 40-69 from the Japan Public Health Center-based Prospective Study followed from 1990 to 2012. TC levels were defined per clinical guidelines: low (<4.66 mmol/l [180 mg/dl]), normal (4.66-5.70 mmol/l [180-220 mg/dl]), and high (≥5.70 mmol/l [220 mg/dl]). Cox proportional hazards regression models were used to determine hazard ratios ( HR) and confidence intervals ( CI) for suicide according to TC level. Mean follow-up time was 19 years for men and 20 years for women. Results There were 185 suicides (men: 107; women: 78) during follow-up. Compared to women with normal TC, women with high TC had a significantly increased risk of suicide ( HR = 1.90, 95% CI, 1.13-3.19). Incremental increases (0.26 mmol/l [10 mg/dl]) of low-density lipoprotein ( HR = 1.11, 95% CI, 1.02-1.21) and non-high-density lipoprotein cholesterol ( HR = 1.09, 95% CI, 1.01-1.18) were also associated with increased risk of suicide in women. There was no association between TC levels, or lipid fractions, and suicide in men. Conclusion High TC levels may be associated with an increased risk of suicide in women. [ABSTRACT FROM AUTHOR]

BACKGROUND: : Knowledge of neural anatomy is fundamental for safe, efficacious use of regional anesthesia. Spinal column procedures, such as a facet joint block, require an accurate understanding of neural pathways relative to anatomic structure. Since Bogduk's report it has been known that human lumbar posterior ramus of the spinal nerve (PRSN) comprises three, equally sized primary branches. However, inconsistencies and controversy remain over the exact locations and pathways of the peripheral portions of the PRSN branches. In this study, the authors investigated the detailed anatomy of the human PRSN. METHODS: : The authors performed ventral dissection in seven cadavers to determine the layout of the PRSN between T10 and L4 spinal segments. They captured three-dimensional images with a laser scanner. For fine detail analysis, specimens from another cadaver were subjected to a modified Spalteholz technique to render all nonnerve tissue transparent. Computer graphics were used to create a three-dimensional structural model. RESULTS: : All three PRSN branches emanated from an ipsilateral origin and passed posterior to the transverse process. The medial PRSN branch consistently passed between the mammillary and accessory processes under the mammilloaccessory ligament. The intermediate branch passed between the longissimus and iliocostalis muscles and extended to the skin. The lateral branch traveled far lateral from the origin. CONCLUSIONS: : The authors created a 3D model of the PRSN in the lumbar segment, which may be useful for planning surgical approaches to dorsal areas of the vertebral column. In addition, this knowledge may improve the accuracy of procedures involving the spinal column, particularly radiofrequency neurolysis of the facet joint. [ABSTRACT FROM AUTHOR]

BACKGROUND: The Japanese Red Cross (JRC) implemented a fully automated pooling and nucleic acid amplification test (NAT) system for testing seronegative donations. The JRC sample repository and repeat blood donations allowed for lookback and follow-up studies of hepatitis B virus (HBV) DNA-positive donors, who tested negative for hepatitis B surface antigen (HBsAg) and anti-hepatitis B core antigen in the JRC screening system. STUDY DESIGN AND METHODS: From February 1, 2000, to March 31, 2003, 17,314,486 units were tested in 50-sample pools with a semiautomated multiplex assay system (AMPLINAT MPX test, Roche). During this period, 328 HBV DNA-positive donations were found. From 26 of these donors, sequential samples were available at short intervals. This enabled us to examine the dynamics of viral markers in acute HBV infection. The length of detectable periods of plasma viremia and antigenemia were estimated by regression analysis from the results obtained in the quantitative polymerase chain reaction assay (JRC) and HBsAg enzyme immunoassay (Auszyme II, AxSYM, Abbott) and chemiluminescence immunoassay (Abbott). RESULTS: The median length of detectable HBV DNA in individual donation and 20-sample minipool (MP) NAT format was estimated to be 74 and 50 days, respectively, whereas the median length of detectable HBsAg was estimated to be 42 days. Six of the 26 donors were infected with mutant viruses, and 3 of these 6 donors did not develop detectable HBsAg during the entire observation period, despite a moderately high viral load of 10(4) to 10(5) HBV DNA copies per mL. CONCLUSION: Transmission of mutant virus may cause occult HBV infection in the acute stage. HBV NAT, even in MP configuration, is more effective than HBsAg testing and capable of interdicting infected donors in the pre- and post-HBsAg window periods. [ABSTRACT FROM AUTHOR]

Abstract: The effect of temperature on the initiation of light-induced defects in a-Se targets of high-gain avalanche rushing photoconductor (HARP) camera tubes was studied. At room temperature, avalanche a-Se was found to be subject to both reversible and irreversible photodarkening. At 35°C, the irreversible photodarkening component was completely absent. This result is attributed to the instantaneous annealing of light-induced metastable coordination defects at elevated temperatures. A model for the formation of permanent crystalline areas at low temperatures via transition states associated with light-induced metastable defects is proposed. [Copyright &y& Elsevier]

Advances in the therapeutic agents used for neoadjuvant chemotherapy (NAC) have recently achieved higher response rates and induced a greater number of pathologic complete responses (pCR) than ever before. The aim of this study is the diagnosis of pCR after NAC by diagnostic imaging of clinical complete response (cCR) patients. This study included 35 breast cancer patients who demonstrated cCR after receiving NAC with a combination of anthracycline and taxane from May 1998 to August 2003. Surgical treatment included breast-conserving therapy followed by radiotherapy or mastectomy. The identity of post-NAC lesions as either a complete response (CR) or partial response (PR) were made by mammography, ultrasonography, and contrast-enhanced computed tomography (CT). Among the 35 patients, 11 achieved pCR, including the disappearance of both invasive and intraductal components. Of the patients achieving pCR, eight were defined as CR and three were determined to be PR by CT. There was a significant relationship between the pCR and the determination of CR by CT. The determination of CR by ultrasonography was indicative of the disappearance of pathologic invasive components. While mammography appeared to reflect the observed histologic results, we did not observe any statistical differences. A subset of cases exhibited discrepancies between the imaging and pathologic results, likely due to the replacement of destroyed tumor cells by fibrosis and granulomatous tissue. The evaluation of CR by CT was significantly indicative of pCR. The positive predictive value, however, was not large enough to avoid surgical treatment. Further studies will be needed to establish a diagnosis of pCR. [ABSTRACT FROM AUTHOR]

Abstract: The quantum efficiency of photo-charge generation and avalanche multiplication in amorphous selenium (a-Se) photodetectors were measured over considerable ranges of photoexcitation wavelengths (420–600nm) and electric fields (10–112.5V/μm) for several different a-Se target thicknesses (8–35μm). An avalanche multiplication factor of 1000 is shown for a 35μm thick a-Se layer at an electric field of 98V/μm. The experimental results on quantum efficiency can be explained by the Onsager theory of electron–hole pair dissociation in conjunction with an electric field-induced delocalization of states. [Copyright &y& Elsevier]

An in-beam gamma-ray spectroscopy study, following a fusion reaction induced by a neutron-rich secondary beam, 46Ar + 9Be, is presented. A low-energy secondary beam of 46Ar at ∼ 5 MeV/ A was developed in order to induce fusion reactions. Gamma-gamma coincidence and excitation function analysis was performed to study high-spin states in the vicinity of 48Ca, 49-52Ti . [ABSTRACT FROM AUTHOR]