Measurements of Strong-Interaction Effects in Kaonic-Helium Isotopes at Sub-eV Precision with X-Ray Microcalorimeters.

We have measured the 3d→2p transition x rays of kaonic ^{3}He and ^{4}He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be 6224.5±0.4(stat)±0.2(syst) eV and 6463.7±0.3(stat)±0.1(syst) eV, and widths to be 2.5±1.0(stat)±0.4(syst) eV and 1.0±0.6(stat)±0.3(stat) eV, for kaonic ^{3}He and ^{4}He, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach and agree with calculations based on optical-potential models.

Search for η

We measured missing mass spectrum of the ^{12}C(γ,p) reaction for the first time in coincidence with potential decay products from η^{'} bound nuclei. We tagged an (η+p) pair associated with the η^{'}N→ηN process in a nucleus. After applying kinematical selections to reduce backgrounds, no signal events were observed in the bound-state region. An upper limit of the signal cross section in the opening angle cosθ_{lab}^{ηp}<-0.9 was obtained to be 2.2 nb/sr at the 90% confidence level. It is compared with theoretical cross sections, whose normalization ambiguity is suppressed by measuring a quasifree η^{'} production rate. Our results indicate a small branching fraction of the η^{'}N→ηN process and/or a shallow η^{'}-nucleus potential.

Dynamics of impurity attraction and repulsion of an intrinsic localized mode in a driven 1-D cantilever array.

Both low frequency and high frequency impurity modes have been produced in a SiN micromechanical cantilever array by illumination with either an infrared or visible laser. When such laser-induced impurities are placed near a driven intrinsic localized mode (ILM), it is either repelled or attracted. By measuring the linear response spectrum for these two cases, it was found that vibrational hopping of the ILM takes place when the natural frequency of the ILM and an intrinsic even symmetry linear local mode are symmetrically located about the driven ILM frequency so that parametric excitation of these two linear modes is enhanced, amplifying the lateral motion of the ILM. Numerical simulations are consistent with these signature findings. It is also demonstrated that the correct sign of the observed interaction can be found with a harmonic lattice-impurity model but the magnitude of the effect is enhanced in a nonlinear lattice.

Experimental observation of the bifurcation dynamics of an intrinsic localized mode in a driven 1D nonlinear lattice.

Linear response spectra of a driven intrinsic localized mode in a micromechanical array are measured as it approaches two fundamentally different kinds of bifurcation points. A linear phase mode associated with this autoresonant state softens in frequency and its amplitude grows as the upper frequency bifurcation point is approached, similar to the soft-mode kinetic transition for a single driven Duffing resonator. A lower frequency bifurcation point occurs when the four-wave-mixing partner of this same phase mode intercepts the top of the extended wave branch, initiating a second kinetic transition process.

Cirrhosis is under-recognised in patients subsequently diagnosed with hepatocellular cancer.

BACKGROUND: Most clinical practice guidelines recommend screening for HCC in patients with cirrhosis. However, patients with compensated cirrhosis are often asymptomatic and may remain unrecognised for years. AIMS: To determine the extent to which cirrhosis is unrecognised in a US Veteran population with HCC, and to evaluate the association between lack of cirrhosis recognition and stage of HCC at diagnosis. METHODS: We reviewed the electronic medical records of a random sample of HCC cases diagnosed in the national Veterans Affairs system between 2005 and 2011. We conducted multivariable analyses adjusting for patients' demographics, comorbidity, aetiology of underlying disease and healthcare utilisation including HCC surveillance. RESULTS: Of 1201 patients with HCC and cirrhosis, 24.6% had unrecognised cirrhosis prior to HCC diagnosis. Older patients [>65 years, odds ratio (OR) 2.32], African Americans (OR 1.93), patients with alcoholic or NAFLD liver disease (OR 1.69 and 4.77 respectively), HIV (OR 3.02), and fewer comorbidities (Deyo 0 vs. 3, OR 2.42) had significantly higher odds of having unrecognised cirrhosis than comparison groups. Furthermore, patients with unrecognised cirrhosis were 6.5 times more likely to have advanced stage HCC at diagnosis. The effect of cirrhosis recognition on HCC stage remained significant after adjusting for pre-specified covariates (OR 3.37). CONCLUSIONS: In one quarter of patients, cirrhosis was unrecognised prior to HCC diagnosis, and this group was significantly more likely to have advanced stage HCC. These findings emphasise the importance of timely evaluation for cirrhosis in at-risk populations as a critical step to improving outcomes for patients with HCC.

Spatial and temporal expression of P-glycoprotein in the congenitally hydrocephalic HTX rat brain.

The purpose of the present study is to examine spatial and temporal expression of P-glycoprotein in the brain of congenitally hydrocephalic HTX rats. P-glycoprotein has been reported not only as a drug efflux pump but also one of the factors that restricts brain edema. We examined the rat brain from postnatal day 1 to 60 using light and electron microscopy, immunohistochemistry, Western immunoblot and reverse transcriptase-polymerase chain reaction (RT-PCR) methods with monoclonal antibody specific for P-glycoprotein. Immunohistochemically, the positive anti-P-glycoprotein reactivity was found in capillaries of the normal control rat cerebrum. In the hydrocephalic HTX rat brains, it was also found in the capillaries, but only very weak to no reactivity was found in the capillaries of the spongy changes and cystic wall in the subcortical and lateral periventricular white matter. Immunoelectron microscopically, the reaction product was found exclusively on the luminal surface of the capillary endothelium in control rats. A tracer study with intracardiac perfusion of lanthanum chloride showed that lanthanum penetrated the tight junctions and passed through the intercellular space. In the Western immunoblot analysis, P-glycoprotein of 170 kDa was detected clearly in most normal control rat brains but it was not found in the hydrocephalic HTX rat brains. Moreover, mdr1 P-glycoprotein gene expression in the subcortical white matter was examined by RT-PCR. It was detected in all normal control rat brains, but not found in the hydrocephalic HTX rat brains. The results suggested that the absence of P-glycoprotein expression in the capillaries of deep subcortical and lateral periventricular white matter of hydrocephalic HTX rats led to a deficiency of the blood-brain barrier and might be related to vasogenic edema and to the formation of the spongy changes and cystic cavities.

Extraction and identification of antioxidants in the roots of yacon (Smallanthus sonchifolius).

Yacon, Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson, Asteraceae, an important economic species grown for its juicy tuberous root, is potentially beneficial in the diet to diabetics. The antioxidative activity of yacon root was studied by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay. Antioxidants were extracted by methanol and isolated and purified by gel permeation chromatography and preparative reverse-phase HPLC. Two of the major antioxidants were identified as chlorogenic acid and tryptophan by NMR and mass spectrometry.

Effect of medication with pravastatin sodium on hemorheological parameters in patients with hyperlipoproteinemia.

Pravastatin sodium, a newly developed potent synthesis inhibitor of HMG-CoA (beta-hydroxy-beta-methylglutaryl-cocarboxylase-A) reductase (Sankyo Co., Ltd., Japan) was medicated, 10 approximately 15 mg/day (mean: 11.1 mg/day) for 10.2 weeks in mean, in 14 patients with primary hyperlipoproteinemia of more than 230 mg/dl of serum cholesterol levels (mean age: 56.9 y.o.). The values of serum cholesterol decreased (from 242 +/- 12 to 207 +/- 22; mg/dl), and of high density lipoprotein (HDL) increased (from 42.3 +/- 8.8 to 45.3 +/- 9.2; mg/dl) significantly (p < 0.05, respectively) 10.2 weeks in mean after medication with pravastatin sodium. The whole blood viscosity, at every shear rate examined, corrected blood viscosity, for the standard hematocrit level of 45%, and plasma fibrinogen decreased significantly (p < 0.05, respectively) at the same time, without showing significant differences any more 10.2 weeks in mean after medication with those in 14 elderly normal subjects (mean age: 56.7 y.o.), which suggested that the hemorheological parameters in patients with primary hyperlipoproteinemia had improved significantly by medication with pravastatin sodium.

Susceptibility of rats of different ages to inoculation with swine haemagglutinating encephalomyelitis virus (a coronavirus) by various routes.

Haemagglutinating encephalomyelitis virus, strain 67N, was used to inoculate 1-, 2-, 4- and 8-week-old rats by the intracerebral (i.c.), intranasal (i.n.), intraperitoneal (i.p.), subcutaneous (s.c.), intravenous (i.v.) and oral routes with graded doses. The routes of infection, in descending order of efficacy, were: i.ci.ns.ci.pi.v. and oral. Rats aged 1 and 2 weeks were generally similar in terms of mortality and mean time to death, regardless of inoculation route, except for the oral route, which had little effect. In comparison with the 1- and 2-week-old rats, the 4-week-old rats were less susceptible to the virus by all routes. Eight-week-old rats inoculated by the i.ci.n. or s.c. routes died, but all those inoculated by other routes survived. To follow the spread of virus in the central nervous system, 4-week-old rats inoculated by the i.c. route were examined. The virus was first detected in the brain on day 1 and in the spinal cord on day 2. The viral titres in both tissues reached a plateau of 10(7) plaque-forming units (PFU)/0.2 g by day 4, at which time clinical signs had developed. By immunohistochemical analysis, virus-specific antigen was found first in the pyramidal cells of the hippocampus and cerebral cortex, and later in the large-sized neurons of the pons and spinal cord. Still later (day 4) immunolabelling was found in Purkinje cells of the cerebellum, but not in the ependymal cells, choroid plexus or other glial cells.

Apneic spells in a patient with myelomeningocele without Chiari type II malformation--case report.

A female neonate with myelomeningocele but without Chiari type II malformation suffered from apneic spells. Magnetic resonance imaging showed no obvious brainstem anomaly. Brainstem auditory evoked potentials were initially abnormal and subsequently deteriorated during the 6 months after birth. The brainstem deficits were not reversed by a ventriculoperitoneal shunt. She died of respiratory distress and cardiac failure at 2 years of age. This case indicates an intrinsic dysfunction in the brainstem of patients with myelomeningocele not complicated by Chiari type II malformation.

Effect of active rest by oral reading on a mirror-drawing task.

This study investigated the effect of active rest on perceptual-motor learning. Two groups received different techniques for promoting recovery during an 8-min. rest period between practice on a mirror-drawing task. The two techniques were active rest by reading orally a book unrelated to the experiment and passive rest during which the group sat without moving the body or thinking about the experiment. Significantly fewer number of errors in the mirror drawing occurred for those subjects who used oral reading during rest. The possibility of raising arousal was discussed.

[A case of recurrent medulloblastoma treated by combination therapy with cisplatinum and tetrahydropyranyladriamycin (PP therapy)].

PP therapy, combination therapy with Cis-platinum (CDDP) and tetrahydropyranyladriamycin (THP-ADR), were performed on a case of recurrent medulloblastoma. CDDP and THP-ADR involve agents difficult to pass the blood brain barrier (BBB), but can pass BBB on the metastatic lesion. PP therapy is considered to be one of the most effective agents for the treatment of recurrent malignant brain tumor.

Switching dynamics and linear response spectra of a driven one-dimensional nonlinear lattice containing an intrinsic localized mode.

An intrinsic localized mode (ILM) represents a localized vibrational excitation in a nonlinear lattice. Such a mode will stay in resonance as the driver frequency is changed adiabatically until a bifurcation point is reached, at which point the ILM switches and disappears. The dynamics behind switching in such a many body system is examined here through experimental measurements and numerical simulations. Linear response spectra of a driven micromechanical array containing an ILM were measured in the frequency region between two fundamentally different kinds of bifurcation points that separate the large amplitude ILM state from the two low amplitude vibrational states. Just as a natural frequency can be associated with a driven harmonic oscillator, a similar natural frequency has been found for a driven ILM via the beat frequency between it and a weak, tunable probe. This finding has been confirmed using numerical simulations. The behavior of this nonlinear natural frequency plays important but different roles as the two bifurcation points are approached. At the upper transition its frequency coalesces with the driver and the resulting bifurcation is very similar to the saddle-node bifurcation of a single driven Duffing oscillator, which is treated in an Appendix. The lower transition occurs when the four-wave mixing partner of the natural frequency of the ILM intersects the topmost extended band mode of the same symmetry. The properties of linear local modes associated with the driven ILM are also identified experimentally for the first time and numerically but play no role in these transitions.

Immunohistochemical study on blood-brain barrier in congenitally hydrocephalic HTX rat brain.

The purpose of the present study is to examine the blood-brain barrier in brain of congenital hydrocephalus HTX rats. We investigated the rat brain from postnatal day 1 to 44 using light and electron microscopy and immunohistochemical methods with monoclonal anti-blood-brain barrier (BBB) antibody. HTX rats developed hydrocephalus at 1-2 days after birth. Most rats succumbed to brain changes within 4-5 weeks. Among 136 HTX rats examined, 45 rats succumbed within 1 week after birth, 29 rats between 1-2 weeks, and 4 rats 27-44 days after birth. Out of 88 hydrocephalic rats 54 showed a marked ventricular dilatation, and 34 showed a mild dilatation. Dilatation of lateral ventricles was mild in the rats at 1-2 days after birth, but 3-14-day-old rats showed moderate or marked dilatation. 15-30 days after birth the rats developed mostly marked dilatation of lateral ventricles and third ventricle. Lateral ventricles and third ventricle showed a symmetric dilatation, but ependymal cell layers were well preserved. Aqueduct exhibited no dilatation in any rat. There were spongy appearances and cystic cavities in the white matter around the lateral ventricles. There were glial fibers and capillaries across the cystic cavities. Cystic lesions were also found in the deep subcortical white matter, consisting of spongy changes with extended extracellular spaces and microcysts in the white matter. Immunohistochemically, the anti-BBB reactivity in the normal control rats was at first weak at 2 weeks after birth and increased with the course of development, prominently 4 weeks after birth. Three- and four-week-old HTX rats with hydrocephalus showed moderate positive anti-BBB reaction in the cerebral cortex, the basal ganglia, and around the aqueduct but only a very weak reaction in the deep subcortical white matter and in the subependymal area of lateral ventricles. Laminin immunoreactivity was not different in the capillaries of hydrocephalic brain as compared with normal brain. Electron microscopically, tight junctions were well formed between endothelial cells of capillaries in the subcortical white matter. Occasionally capillaries with partial defect of basal membrane could be found, where the cytoplasm of endothelial cell was protruding between pericytic cytoplasm. Swelling of astrocytic end-feet were found around the microvessels. The results suggest that at the site of the lesion there is underdevelopment or immaturity of the blood-brain barrier.

Replication of rat coronavirus in a rat cell line, LBC. Brief report.

Rat coronavirus readily propagated and induced marked cytopathic effect in a rat cell line, LBC cell culture, which provided a sensitive, practical assay system for viral infectivity and neutralizing antibody, and a satisfactory source of the virus.