Sequential Nature of (p,3p) Two-Proton Knockout from Neutron-Rich Nuclei.

Twenty-one two-proton knockout (p,3p) cross sections were measured from neutron-rich nuclei at ∼250 MeV/nucleon in inverse kinematics. The angular distribution of the three emitted protons was determined for the first time, demonstrating that the (p,3p) kinematics are consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p,3p) over (p,2p) inclusive cross sections follow the trend of other many-nucleon removal reactions, further reinforcing the sequential nature of (p,3p) in neutron-rich nuclei.

Serum immunoglobulin G antibody titer to Fusobacterium nucleatum is associated with unfavorable outcome after stroke.

Stroke can be a cause of death, while in non-fatal cases it is a common cause of various disabilities resulting from associated brain damage. However, whether a specific periodontal pathogen is associated with increased risk of unfavorable outcome after stroke remains unknown. We examined risk factors for unfavorable outcome following stroke occurrence, including serum antibody titers to periodontal pathogens. The enrolled cohort included 534 patients who had experienced an acute stroke, who were divided into favorable (n = 337) and unfavorable (n = 197) outcome groups according to modified ranking scale (mRS) score determined at 3 months after onset (favorable = score 0 or 1; unfavorable = score 2-6). The associations of risk factors with unfavorable outcome, including serum titers of IgG antibodies to 16 periodontal pathogens, were examined. Logistic regression analysis showed that the initial National Institutes of Health stroke scale score [odds ratio (OR) = 1·24, 95% confidence interval (CI) = 1·18-1·31, P < 0·001] and C-reactive protein (OR = 1·29, 95% CI = 1·10-1·51, P = 0·002) were independently associated with unfavorable outcome after stroke. Following adjustment with those, detection of the antibody for Fusobacterium nucleatum ATCC 10953 in serum remained an independent predictor of unfavorable outcome (OR = 3·12, 95% CI = 1·55-6·29, P = 0·002). Determination of the antibody titer to F. nucleatum ATCC 10953 in serum may be useful as a predictor of unfavorable outcome after stroke.

78Ni revealed as a doubly magic stronghold against nuclear deformation.

Nuclear magic numbers correspond to fully occupied energy shells of protons or neutrons inside atomic nuclei. Doubly magic nuclei, with magic numbers for both protons and neutrons, are spherical and extremely rare across the nuclear landscape. Although the sequence of magic numbers is well established for stable nuclei, experimental evidence has revealed modifications for nuclei with a large asymmetry between proton and neutron numbers. Here we provide a spectroscopic study of the doubly magic nucleus 78Ni, which contains fourteen neutrons more than the heaviest stable nickel isotope. We provide direct evidence of its doubly magic nature, which is also predicted by ab initio calculations based on chiral effective-field theory interactions and the quasi-particle random-phase approximation. Our results also indicate the breakdown of the neutron magic number 50 and proton magic number 28 beyond this stronghold, caused by a competing deformed structure. State-of-the-art phenomenological shell-model calculations reproduce this shape coexistence, predicting a rapid transition from spherical to deformed ground states, with 78Ni as the turning point.

Prominence of Pairing in Inclusive (p,2p) and (p,pn) Cross Sections from Neutron-Rich Nuclei.

Fifty-five inclusive single nucleon-removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at ∼250 MeV/nucleon are measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons as compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting, contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semimicroscopic model predictions, highlighting the enhanced role of low-lying level densities in nucleon-removal cross sections from loosely bound nuclei.

Erratum: Persistence of the Z=28 Shell Gap Around

This corrects the article DOI: 10.1103/PhysRevLett.119.192501.

Persistence of the Z=28 Shell Gap Around

In-beam γ-ray spectroscopy of ^{79}Cu is performed at the Radioactive Isotope Beam Factory of RIKEN. The nucleus of interest is produced through proton knockout from a ^{80}Zn beam at 270 MeV/nucleon. The level scheme up to 4.6 MeV is established for the first time and the results are compared to Monte Carlo shell-model calculations. We do not observe significant knockout feeding to the excited states below 2.2 MeV, which indicates that the Z=28 gap at N=50 remains large. The results show that the ^{79}Cu nucleus can be described in terms of a valence proton outside a ^{78}Ni core, implying the magic character of the latter.

Gamma Decay of Unbound Neutron-Hole States in

Excited states in the nucleus ^{133}Sn, with one neutron outside the double magic ^{132}Sn core, were populated following one-neutron knockout from a ^{134}Sn beam on a carbon target at relativistic energies at the Radioactive Isotope Beam Factory at RIKEN. Besides the γ rays emitted in the decay of the known neutron single-particle states in ^{133}Sn additional γ strength in the energy range 3.5-5.5 MeV was observed for the first time. Since the neutron-separation energy of ^{133}Sn is low, S_{n}=2.402(4) MeV, this observation provides direct evidence for the radiative decay of neutron-unbound states in this nucleus. The ability of electromagnetic decay to compete successfully with neutron emission at energies as high as 3 MeV above threshold is attributed to a mismatch between the wave functions of the initial and final states in the latter case. These findings suggest that in the region southeast of ^{132}Sn nuclear structure effects may play a significant role in the neutron versus γ competition in the decay of unbound states. As a consequence, the common neglect of such effects in the evaluation of the neutron-emission probabilities in calculations of global ß-decay properties for astrophysical simulations may have to be reconsidered.

A metal sulfide photocatalyst composed of ubiquitous elements for solar hydrogen production.

A visible-light-sensitive tin sulfide photocatalyst was designed based on a ubiquitous element strategy and density functional theory (DFT) calculations. Computational analysis suggested that tin monosulfide (SnS) would be more efficient than SnS2 as a photocathode for hydrogen production because of the low ionization potential and weak ionic character of SnS. To test this experimentally, nanoparticles of SnS were loaded onto a mesoporous electrode using a wet chemical method, and the bandgap of the synthesized SnS quantum dots was found to be tunable by adjusting the number of successive ionic layer adsorption and reaction (SILAR) cycles, which controls the magnitude of the quantum confinement effect. Efficient hydrogen production was achieved when the bandgap of SnS was wider than that of the bulk form.

Extension of the N=40 Island of Inversion towards N=50: Spectroscopy of (66)Cr, (70,72)Fe.

We report on the measurement of the first 2(+) and 4(+) states of (66)Cr and (70,72)Fe via in-beam γ-ray spectroscopy. The nuclei of interest were produced by (p,2p) reactions at incident energies of 260 MeV/nucleon. The experiment was performed at the Radioactive Isotope Beam Factory, RIKEN, using the DALI 2γ-ray detector array and the novel MINOS device, a thick liquid hydrogen target combined with a vertex tracker. A low-energy plateau of 2(1)(+) and 4(1)(+) energies as a function of the neutron number was observed for N≥38 and N≥40 for even-even Cr and Fe isotopes, respectively. State-of-the-art shell model calculations with a modified Lenzi-Nowacki-Poves-Sieja (LNPS) interaction in the pfg(9/2)d(5/2) valence space reproduce the observations. Interpretation within the shell model shows an extension of the island of inversion at N=40 for more neutron-rich isotopes towards N=50.

Low-Lying Structure of (50)Ar and the N=32 Subshell Closure.

The low-lying structure of the neutron-rich nucleus (50)Ar has been investigated at the Radioactive Isotope Beam Factory using in-beam γ-ray spectroscopy with (9)Be((54)Ca,(50)Ar+γ)X, (9)Be((55)Sc,(50)Ar+γ)X, and (9)Be((56)Ti,(50)Ar+γ)X multinucleon removal reactions at ∼220 MeV/u. A γ-ray peak at 1178(18) keV is reported and assigned as the transition from the first 2(+) state to the 0(+) ground state. A weaker, tentative line at 1582(38) keV is suggested as the 4(1)(+)→2(1)(+) transition. The experimental results are compared to large-scale shell-model calculations performed in the sdpf model space using the SDPF-MU effective interaction with modifications based on recent experimental data for exotic calcium and potassium isotopes. The modified Hamiltonian provides a satisfactory description of the new experimental results for (50)Ar and, more generally, reproduces the energy systematics of low-lying states in neutron-rich Ar isotopes rather well. The shell-model calculations indicate that the N=32 subshell gap in (50)Ar is similar in magnitude to those in (52)Ca and (54)Ti and, notably, predict an N=34 subshell closure in (52)Ar that is larger than the one recently reported in (54)Ca.

Evidence for a new nuclear 'magic number' from the level structure of 54Ca.

Atomic nuclei are finite quantum systems composed of two distinct types of fermion--protons and neutrons. In a manner similar to that of electrons orbiting in an atom, protons and neutrons in a nucleus form shell structures. In the case of stable, naturally occurring nuclei, large energy gaps exist between shells that fill completely when the proton or neutron number is equal to 2, 8, 20, 28, 50, 82 or 126 (ref. 1). Away from stability, however, these so-called 'magic numbers' are known to evolve in systems with a large imbalance of protons and neutrons. Although some of the standard shell closures can disappear, new ones are known to appear. Studies aiming to identify and understand such behaviour are of major importance in the field of experimental and theoretical nuclear physics. Here we report a spectroscopic study of the neutron-rich nucleus (54)Ca (a bound system composed of 20 protons and 34 neutrons) using proton knockout reactions involving fast radioactive projectiles. The results highlight the doubly magic nature of (54)Ca and provide direct experimental evidence for the onset of a sizable subshell closure at neutron number 34 in isotopes far from stability.

Efficacy and effect on plasma B-type natriuretic peptide concentration of losartan-hydrochlorothiazide for hypertension uncontrolled by losartan-based therapy: subanalysis of a Multicentre Prospective Observational Study.

Many patients with hypertension have difficulty achieving their target blood pressure (BP). Therefore combination therapy, for example with an angiotensin II receptor blocker (ARB) and a diuretic, may be recommended. We previously evaluated the efficacy and safety of losartan (LOS) 50 mg - hydrochlorothiazide (HCTZ) 12.5 mg, as well as its effect on the plasma concentration of B-type natriuretic peptide (BNP, a prognostic marker for cardiovascular events), in patients with hypertension uncontrolled by ≥3 months of ARB-based therapy. The present subanalysis used data from patients who received LOS-based therapy before switching to LOS-HCTZ. Efficacy, safety, and changes in blood biochemical variables including BNP were evaluated. After excluding 4 patients with protocol violations, data from 35 patients (aged 36-79 years, mean 63 years; 66% male) were used in the safety analysis. The efficacy analysis used data from the 30 patients who were followed up for 12 months. Systolic/diastolic BP decreased from 156±12/87±11 mmHg at baseline to 125±11/73±10 mmHg at 12 months (p<0.001). After 12 months, half of the patients achieved their target BP as defined by the Japanese Society of Hypertension Guidelines for the Management of Hypertension 2004. In 12 patients with baseline plasma BNP concentration ≥20 pg/mL, BNP decreased from 78.3±18.8 pg/mL to 57.3±17.7 pg/mL (p<0.01). 3 patients experienced adverse events, one of which was cardiovascular. LOS-HCTZ is efficacious, has a good safety profile, and decreases plasma BNP concentration.

Significance of plasma levels of pigment epithelium-derived factor as determined by multidetector row computed tomography in patients with mild chronic kidney disease and/or coronary artery disease.

Little is known about the association between plasma levels of pigment epithelium-derived factor (PEDF), coronary artery disease (CAD) and/or chronic kidney disease (CKD). This study evaluated 289 consecutive patients with chest pain or at least one coronary risk factor who underwent coronary angiography using multidetector row computed tomography (MDCT). Presence of CAD and CKD, CAD severity (i.e. number of significantly stenosed coronary vessels, described as vessel disease [VD]), coronary calcification scores, visceral fat area (VFA), subcutaneous fat area on MDCT, and metabolic biomarkers were recorded. PEDF levels correlated significantly with sex, VFA, CKD presence/hyperuricaemia and high-density lipoprotein cholesterol levels. PEDF levels were closely associated with CKD and were significantly higher in CKD patients than in non-CKD patients, regardless of the presence of CAD. CKD patients with two-VD or three-VD had higher plasma PEDF levels than non-CKD patients with two-VD or three-VD. It is concluded that PEDF may be associated with CKD regardless of the presence of CAD.

Low-dose corticosteroids reduce relapses in neuromyelitis optica: a retrospective analysis.

Neuromyelitis optica (NMO) is a relapsing neurologic disease characterized by severe optic neuritis and transverse myelitis. A disease-modifying therapy for NMO has not been established. We retrospectively analysed the effect of low-dose corticosteroid (CS) monotherapy on the annual relapse rate in nine patients with NMO. We divided the clinical course in each patient into two periods; the CS Period in which CS was administered, and the No CS Period in which CS was not administered. Periods related to other immunological therapies, such as high-dose methylprednisolone, immunosuppressants, interferon-beta, and plasma exchange, were excluded. As a result, the annual relapse rate during the CS Periods [median, 0.49 (range, 0-1.31)] was found to be significantly lower than that during the No CS Periods [1.48 (0.65-5.54)]. As for the dose of CS, relapses occurred significantly more frequently with ;10 mg/day or less' than with ;over 10 mg/day' (odds ratio: 8.75). The results of the present study suggest a beneficial effect of low-dose CS monotherapy in reducing relapses in NMO.

Therapeutic efficacy of plasma exchange in NMO-IgG-positive patients with neuromyelitis optica.

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system (CNS) with a poor prognosis in terms of the optic-spinal function. Recently, a serum autoantibody (NMO-IgG) binding to the blood-brain barrier region was detected exclusively in patients with NMO and its high risk group. We treated six NMO-IgG-positive patients (all female; age 21-67 years old, median 41; three with optic neuritis and three with myelitis) who were unresponsive to high-dose intravenous methylprednisolone (HIMP), with plasma exchange (PE) (three to five exchanges, 2-3 L each). Three of the patients (one with optic neuritis and two with myelitis) showed definite functional improvement following PE. The clinical improvement started to appear after one or two exchanges, while there was little or no improvement in the other three patients. Such quick clinical responses to PE suggest a pathogenetic role of humoral immune factors in NMO, although delayed responses to the corticosteroid therapy might have contributed to the therapeutic efficacy, in part. Further clinical and in vitro studies are needed to determine whether the removal of NMO-IgG is directly relevant to the therapeutic efficacy. PE may hasten the functional recovery from corticosteroid-resistant relapses in some NMO-IgG-positive patients with NMO.

Clinical features of chromosome 16q22.1 linked autosomal dominant cerebellar ataxia in Japanese.

Chromosome 16q22.1-linked autosomal dominant cerebellar ataxia (16q-ADCA) is strongly associated with a substitution in the puratrophin-1 gene. This locus overlaps with spinocerebellar ataxia type 4 (SCA4) which shows ataxia with prominent sensory axonal neuropathy. We found that 16q-ADCA is a common ADCA subtype in the Tohoku District of Japan. The clinical feature of Japanese 16q-ADCA is characterized as late-onset pure cerebellar ataxia.

CSF tau protein: a new prognostic marker for Guillain-Barré syndrome.

We measured the CSF tau protein levels in 26 patients with Guillain-Barré syndrome. The levels of the poor outcome group (Hughes grade at 6 months was between II and VI, n = 6) were higher than those of the good outcome group (0 or I, n = 20) (p < 0.0005). The higher levels of CSF tau may reflect axonal degeneration and could predict a poor clinical outcome in Guillain-Barré syndrome.

Clinical and MRI features of Japanese patients with multiple sclerosis positive for NMO-IgG.

This study investigates the relation between the serological status of NMO (neuromyelitis optica)-IgG and the clinical and MRI features in Japanese patients with multiple sclerosis. Serum NMO-IgG was tested in 35 Japanese patients diagnosed with multiple sclerosis, including 19 with the optic-spinal form of multiple sclerosis (OSMS), three with the spinal form of multiple sclerosis (SMS), and 13 with the conventional form of multiple sclerosis (CMS), which affects the brain. NMO-IgG was detected in 14 patients, 12 with OSMS and 2 with CMS. In these patients, longitudinally extensive (> 3 vertebral segments) spinal cord lesions (93% v 57%) and permanent, complete blindness (no perception of light) in at least one eye (50% v 0%) were the noticeable features as compared with NMO-IgG-negative OSMS. The two patients having CMS with NMO-IgG had unusual brain lesions, but in other respects had features suggesting OSMS. NMO-IgG was detected in more than half the number of patients with OSMS and in some patients with CMS. This newly discovered serum autoantibody was markedly associated with longitudinally extensive spinal cord lesions and with complete blindness, suggesting severe optic-spinal disease.

Fatal hepatitis B virus reactivation in a chronic myeloid leukemia patient during imatinib mesylate treatment.

Reactivation of chronic hepatitis B virus (HBV) infection in patients undergoing chemotherapy is well-documented, but reactivation during imatinib mesylate treatment has not been reported. This study reports a 54-year-old man, without prior liver dysfunction but with chronic HBV infection, in whom fatal HBV reactivation occurred during treatment of chronic myeloid leukemia (CML) with imatinib mesylate. He developed fulminant hepatitis followed by marked elevation of HBV DNA polymerase, probably from the lymphocytopenic and immunosuppressive status induced by imatinib mesylate. Imatinib mesylate is widely used to treat CML patients. Although therapy with imatinib mesylate is generally well tolerated, the case presented here suggests that viral reactivation should be considered, even when using imatinib mesylate to treat CML.