Photoemission Orbital Tomography Using a Robust Sparse PhaseLift

Photoemission orbital tomography (POT) from photoelectron momentum maps (PMMs) is a powerful technique that visualizes the shape of the molecular orbitals (MOs) of molecular films. For further utilization of POT, a simple and low-cost method of POT is highly required. Here, we propose a new POT method based on the PhaseLift algorithm (PhaseLift POT). This method utilizes a lifting procedure to convert the PMM, which is a second-order polynomial of MO coefficients, into a first-order polynomial of the lifted MO coefficients and further relaxes the equality constraint for a given PMM. We also established a method to improve the accuracy of phase retrieval from the noisy PMM data by using sparsity for MO coefficients (sparse PhaseLift POT). These methods make it possible to reconstruct the three-dimensional MOs, including phases of the wave function, directly from a single experimental PMM. This method can also precisely determine the adsorption-induced molecular deformations with an accuracy of 0.05 [Å]. Furthermore, the robust sparse PhaseLift POT is robust against unavoidable noise in the experimental PMMs due to the relaxation of the matching condition for a given PMM. Therefore, this will be an innovative tool for POT, especially for analyzing the dynamics of the molecules during the chemical reaction and excitation processes.

An Initiative to Improve 30-Day Readmission Rates Using a Transitions-of-Care Clinic Among a Mixed Urban and Rural Veteran Population

BACKGROUND/OBJECTIVE

Hospital readmissions in the United States, especially in patients at high-risk, cost more than $17 billion annually. Although care transitions is an important area of research, data are limited regarding its efficacy, especially among rural patients. In this study, we describe a novel transitions-of-care clinic (TOCC) to reduce 30-day readmissions in a Veterans Health Administration setting that serves a high proportion of rural veterans.

METHODS

In this quality improvement initiative we conducted a pre-post study evaluating clinical outcomes in adult patients at high risk for 30-day readmission (Care Assessment Needs score > 85) discharged from the Iowa City Veterans Affairs (ICVA) Health Care System from 2017 to 2020. The ICVA serves 184,000 veterans across 50 counties in eastern Iowa, western Illinois, and northern Missouri, with more than 60% of these patients residing in rural areas. We implemented a multidisciplinary TOCC to provide in-person or virtual follow-up to high-risk veterans after hospital discharge. The main purpose of this study was to assess how TOCC follow-up impacted the monthly 30-day patient readmission rate.

RESULTS

The TOCC resulted in a 19.2% relative reduction in 30-day readmission rates in the 12-month postimplementation period compared to the preimplementation period (9.2% vs 11.4%, P = .04). Virtual visits were more popular than in-person visits among both urban and rural veterans. There was no difference in outcomes between these two follow-up options, and both groups had reduced readmission rates compared to non-TOCC follow-up.

CONCLUSIONS

A multidisciplinary TOCC within the ICVA featuring both virtual and in-person visits reduced the 30-day readmission rate. This reduction was particularly notable among patients with congestive heart failure.

Differentiation of Jugular Foramen Paragangliomas versus Schwannomas Using Golden-Angle Radial Sparse Parallel Dynamic Contrast-Enhanced MRI

BACKGROUND AND PURPOSE

Accurate differentiation of paragangliomas and schwannomas in the jugular foramen has important clinical implications because treatment strategies may vary but differentiation is not always straightforward with conventional imaging. Our aim was to evaluate the accuracy of both qualitative and quantitative metrics derived from dynamic contrast-enhanced MR imaging using golden-angle radial sparse parallel MR imaging to differentiate paragangliomas and schwannomas in the jugular foramen.

MATERIALS AND METHODS

A retrospective study of imaging data was performed on patients (n = 30) undergoing MR imaging for jugular foramen masses with the golden-angle radial sparse parallel MR imaging technique. Imaging data were postprocessed to obtain time-intensity curves and quantitative parameters. Data were normalized to the dural venous sinus for relevant parameters and analyzed for statistical significance using a Student t test. A univariate logistic model was created with a binary output, paraganglioma or schwannoma, using a wash-in rate as a variable. Additionally, lesions were clustered on the basis of the wash-in rate and washout rate using a 3-nearest neighbors method.

RESULTS

There were 22 paragangliomas and 8 schwannomas. All paragangliomas demonstrated a type 3 time-intensity curve, and all schwannomas demonstrated a type 1 time-intensity curve. There was a statistically significant difference between paragangliomas and schwannomas when comparing their values for area under the curve, peak enhancement, wash-in rate, and washout rate. A univariate logistic model with a binary output (paraganglioma or schwannoma) using wash-in rate as a variable was able to correctly predict all observed lesions (P < .001). All 30 lesions were classified correctly by using a 3-nearest neighbors method.

CONCLUSIONS

Paragangliomas at the jugular foramen can be reliably differentiated from schwannomas using golden-angle radial sparse parallel MR imaging-dynamic contrast-enhanced imaging when imaging characteristics cannot suffice.

E_{8} Spectra of Quasi-One-Dimensional Antiferromagnet BaCo_{2}V_{2}O_{8} under Transverse Field

We report ^{51}V NMR and inelastic neutron scattering (INS) measurements on a quasi-1D antiferromagnet BaCo_{2}V_{2}O_{8} under transverse field along the [010] direction. The scaling behavior of the spin-lattice relaxation rate above the Néel temperatures unveils a 1D quantum critical point (QCP) at H_{c}^{1D}≈4.7  T, which is masked by the 3D magnetic order. With the aid of accurate analytical analysis and numerical calculations, we show that the zone center INS spectrum at H_{c}^{1D} is precisely described by the pattern of the 1D quantum Ising model in a magnetic field, a class of universality described in terms of the exceptional E_{8} Lie algebra. These excitations are nondiffusive over a certain field range when the system is away from the 1D QCP. Our results provide an unambiguous experimental realization of the massive E_{8} phase in the compound, and open a new experimental route for exploring the dynamics of quantum integrable systems as well as physics beyond integrability.

Implementing a Telehospitalist Program Between Veterans Health Administration Hospitals: Outcomes, Acceptance, and Barriers to Implementation

BACKGROUND

Telehospitalist services are an innovative alternative approach to address staffing issues in rural and small hospitals.

OBJECTIVE

To determine clinical outcomes and staff and patient satisfaction with a novel telehospitalist program among Veterans Health Administration (VHA) hospitals.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a mixed-methods evaluation of a quality improvement program with pre- and postimplementation measures. The hub site was a tertiary (high-complexity) VHA hospital, and the spoke site was a 10-bed inpatient medical unit at a rural (low-complexity) VHA hospital. All patients admitted during the study period were assigned to the spoke site.

INTERVENTION

Real-time videoconferencing was used to connect a remote hospitalist physician with an on-site advanced practice provider and patients. Encounters were documented in the electronic health record.

MAIN OUTCOMES

Process measures included workload, patient encounters, and daily census. Outcome measures included length of stay (LOS), readmission rate, mortality, and satisfaction of providers, staff, and patients. Surveys measured satisfaction. Qualitative analysis included unstructured and semi-structured interviews with spoke-site staff.

RESULTS

Telehospitalist program implementation led to a significant reduction in LOS (3.0 [SD, 0.7] days vs 2.3 [SD, 0.3] days). The readmission rate was slightly higher in the telehospitalist group, with no change in mortality rate. Satisfaction among teleproviders was very high. Hub staff perceived the service as valuable, though satisfaction with the program was mixed. Technology and communication challenges were identified, but patient satisfaction remained mostly unchanged.

CONCLUSION

Telehospitalist programs are a feasible and safe way to provide inpatient coverage and address rural hospital staffing needs. Ensuring adequate technological quality and addressing staff concerns in a timely manner can enhance program performance.

Therapeutics potentiating microglial p21-Nrf2 axis can rescue neurodegeneration caused by neuroinflammation

Neurodegenerative disorders are caused by progressive neuronal loss, and there is no complete treatment available yet. Neuroinflammation is a common feature across neurodegenerative disorders and implicated in the progression of neurodegeneration. Dysregulated activation of microglia causes neuroinflammation and has been highlighted as a treatment target in therapeutic strategies. Here, we identified novel therapeutic candidate ALGERNON2 (altered generation of neurons 2) and demonstrate that ALGERNON2 suppressed the production of proinflammatory cytokines and rescued neurodegeneration in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease model. ALGERNON2 stabilized cyclinD1/p21 complex, leading to up-regulation of nuclear factor erythroid 2-related factor 2 (Nrf2), which contributes to antioxidative and anti-inflammatory responses. Notably, ALGERNON2 enhanced neuronal survival in other neuroinflammatory conditions such as the transplantation of induced pluripotent stem cell-derived dopaminergic neurons into murine brains. In conclusion, we present that the microglial potentiation of the p21-Nrf2 pathway can contribute to neuronal survival and provide novel therapeutic potential for neuroinflammation-triggered neurodegeneration.

Serum copeptin is a new biomarker of continuous-positive-airway-pressure treatment in severe obstructive sleep apnea

Introduction

Copeptin, the C-terminal fragment of antidiuretic hormone (ADH), is a biomarker which has been reported to be increased in cardiovascular and cerebrovascular diseases, thus playing a role in predicting their prognosis. Patients with obstructive sleep apnea syndrome (OSA) have been demonstrated to have a high risk for developing these vascular diseases. However, there have been no authentic reports concerning the effect of continuous positive airway pressure (CPAP) on serum copeptin levels in OSA patients.

Purpose

We hypothesis that CPAP treatment substantially modifies copeptin levels in OSA patients.

Methods

A total of 60 OSA patients confirmed by polysomnographic examinations was divided into two groups: a mild-moderate OSA (apnea-hypopnea index: AHI &lt;30/h) group and a severe OSA (AHI ≥30/h) group. Blood samples were collected early in the morning after overnight fasting, and serum copeptin and ADH levels were measured with an enzyme immunoassay method. In patients initiated with CPAP, hormone levels were measured before and after CPAP treatment.

Results

Twenty-one patients (age: 54.7±12.4 y, male: 17, NT-proBNP: 45.3±44.2 pg/mL) were diagnosed as having mild-moderate OSA (AHI: 16.5±8.4/h), while 39 patients (age: 57.8±11.4y, male: 29, NT-proBNP: 73.7±87.3 pg/mL) were diagnosed as severe OSA (AHI: 49.5±21.1/h). As a whole, there were no significant differences in copeptin and ADH levels between mild-moderate OSA and severe OSA groups (copeptin: 2.1±1.4 pmol/L vs. 1.9±1.4, ADH: 2.3±2.6 pg/dL vs. 2.0±0.7). In 26 severe OSA patients (age: 55.9±12.9y, male: 23, NT-proBNP: 63.3±85.2 pg/mL), these hormones were again evaluated after CPAP initiation. AHI was significantly improved after CPAP treatment (45.5±20.8/h vs. 5.0±5.0, P&lt;0.01). Although the ADH level was changed from 1.85±0.77 pg/dL to 1.68±0.99, the difference did not reach the statistical significance. The copeptin level was certainly decreased after CPAP by 26% (2.29±2.63 pmol/L vs. 1.69±1.68, P&lt;0.01) (Figure 1).

Conclusions

Serum copeptin levels decreased after CPAP treatment in patients with severe OSA. Copeptin, but not ADH, can be considered as a new biomarker for predicting cardio/cerebrovascular events in severe OSA patients.

Figure 1

Funding Acknowledgement

Type of funding source: None

QUANTITATIVE ESTIMATION OF EXPOSURE INHOMOGENEITY IN TERMS OF EYE LENS AND EXTREMITY MONITORING FOR RADIATION WORKERS IN THE NUCLEAR INDUSTRY

To manage the equivalent doses for radiation workers, exposure inhomogeneity is an important factor in the decision-making process related to protection measures and additional monitoring. Our previous study proposed the methodology to evaluate the inhomogeneity of exposure quantitatively. In this study, we applied proposed method to five different types of actual exposure situations encountered in the nuclear industry. Two of them were conventionally characterized as homogeneous exposure, and the other three were conventionally characterized as inhomogeneous exposure. The evaluation of homogeneity exposure was conducted using Monte Carlo calculations with two simplified models, which were then verified with phantom experiments. Consequently, all of the evaluations reproduced the experimental results, implying that our proposed method would be applicable for actual work conditions in the nuclear industry. Furthermore, the two presumed homogeneous exposure situations were found to be rather inhomogeneous because of the contribution of positrons and the limited source region. The results also show that the worker's posture has an impact on the inhomogeneity rather than the energy of incident radiation in nuclear works. The investigation also implies that obtaining the information on the most probable posture of the exposed worker, as well as the existence of the weekly penetrating radiation such as β± ray as a main source of exposure would be the key for more precise estimation.

Dynamic Contrast-Enhanced MRI to Differentiate Parotid Neoplasms Using Golden-Angle Radial Sparse Parallel Imaging

BACKGROUND AND PURPOSE

Conventional imaging frequently shows overlapping features between benign and malignant parotid neoplasms. We investigated dynamic contrast-enhanced MR imaging using golden-angle radial sparse parallel imaging in differentiating parotid neoplasms.

MATERIALS AND METHODS

For this retrospective study, 41 consecutive parotid neoplasms were imaged with dynamic contrast-enhanced MR imaging with golden-angle radial sparse parallel imaging using 1-mm in-plane resolution. The temporal resolution was 3.4 seconds for 78.2 seconds and 8.8 seconds for the remaining acquisition. Three readers retrospectively and independently created and classified time-intensity curves as follows: 1) continuous wash-in; 2) rapid wash-in, subsequent plateau; and 3) rapid wash-in with washout. Additionally, time-intensity curve-derived semiquantitative metrics normalized to the ipsilateral common carotid artery were recorded. Diagnostic performance for the prediction of neoplasm type and malignancy was assessed. Subset multivariate analysis (n = 32) combined semiquantitative time-intensity curve metrics with ADC values.

RESULTS

Independent time-intensity curve classification of the 41 neoplasms produced moderate-to-substantial interreader agreement (κ = 0.50-0.79). The time-intensity curve classification threshold of ≥2 predicted malignancy with a positive predictive value of 56.0%-66.7%, and a negative predictive value of 92.0%-100%. The time-intensity curve classification threshold of <2 predicted pleomorphic adenoma with a positive predictive value of 87.0%-95.0% and a negative predictive value of 76.0%-95.0%. For all readers, type 2 and 3 curves were associated with malignant neoplasms (P < .001), and type 1 curves, with pleomorphic adenomas (P < .001). Semiquantitative analysis for malignancy prediction yielded an area under the receiver operating characteristic curve of 0.85 (95% CI, 0.73-0.99). Combining time-to-maximum and ADC predicts pleomorphic adenoma better than either metric alone (P < .001).

CONCLUSIONS

Golden-angle radial sparse parallel MR imaging allows high spatial and temporal resolution permeability characterization of parotid neoplasms, with a high negative predictive value for malignancy prediction. Combining time-to-maximum and ADC improves pleomorphic adenoma prediction compared with either metric alone.

Acculturation, Biculturalism and Cancer Risk and Preventive Behaviors Among Pacific Islander Immigrant Youths in Hawaii

Background: Culture is an important force which affects health behaviors linked to cancer risks among immigrants. Studies have demonstrated the process of acculturation can produce a form of stress that impact health negatively. On the other hand, research suggests that biculturalism, defined as the combining and practicing of customs from two cultures, may be a healthy approach to acculturation. Biculturalism is especially relevant for youth immigrants as their cultural identities are still developing. Pacific Islanders, a fastest growing populations in the US, often experience discrimination in the society at large and in the health care system. Pacific Islander youth in the US navigate between two cultural identities: their native culture as they live in a close-knit community that still maintains strong cultural norms and values, and the dominant American culture that they face once they step outside their community. This is one of the rare studies that examine the relationship between acculturation and cancer preventive behaviors among Pacific Islander youth. Aim: We aim to study the process through which biculturalism influences cancer risk and preventive behaviors such as smoking, sunscreen applications, physical activity and healthy eating among Pacific Islander youth immigrants in Hawaii. Specifically, we map the process of influence that links biculturalism to self-esteem and to these cancer risk and preventive behaviors. Methods: Using survey data from 284 Pacific Islander youth, we developed and tested a theoretically driven model that specifies the relationship among variables listed above. Results: Results show that self-esteem serves as an important mediator connecting biculturalism to cancer preventive behaviors. While biculturalism did not have a direct influence on behaviors and outcomes, it led to increased self-esteem which, in turn, directly influenced attitudes about sunscreen application, physical activity and healthy eating. However, there was neither direct nor indirect link between biculturalism and smoking. Conclusion: While numerous studies have shown links between biculturalism and health, not many studies focus on the specific process through which the influence is exerted. This study provides an important insight into the process through which biculturalism impacts cancer preventive behaviors among minority youth in America. Data from the study showed a clear relationship between biculturalism, self-esteem, their attitudes and behavior related to cancer prevention among Pacific Islander youth living in Hawaii. This study provides insights into potentially novel methods and interventions designed to increase cancer preventive behaviors among migrant youth by dually promoting adoption of U.S. cultural norms, while concurrently embracing an individual´s historic cultural identity.

Head and Neck MRI Findings in CHARGE Syndrome

Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth and/or development, Genital and/or urinary abnormalities, and Ear abnormalities and deafness (CHARGE) syndrome is a disorder with multiple congenital anomalies seen on imaging. A retrospective review of 10 patients with CHARGE syndrome who underwent MR imaging of the brain as part of a preoperative evaluation for cochlear implantation was conducted. Structural abnormalities of the entire MR imaging of the head were evaluated, including the auditory system, olfactory system, face, skull base, and central nervous system. The most frequent MR imaging findings included dysplasias of the semicircular canals and hypoplasia of the frontal lobe olfactory sulci. Less frequent findings included cleft lip/palate and coloboma. Our study uncovered new findings of a J-shaped sella, dorsal angulation of the clivus, and absent/atrophic parotid glands, not previously described in patients with CHARGE. Our results emphasize the utility of MR imaging in the diagnosis and management of patients with CHARGE syndrome.

Evaluation of absolute measurement using a 4π plastic scintillator for the 4πβ-γ coincidence counting method

Absolute measurement by the 4πβ-γ coincidence counting method was conducted by two photomultipliers facing across a plastic scintillator to be focused on β ray counting efficiency. The detector was held with a through-hole-type NaI(Tl) detector. The results include absolutely determined activity and its uncertainty especially about extrapolation. A comparison between the obtained and known activities showed agreement within their uncertainties.

Order by Quenched Disorder in the Model Triangular Antiferromagnet RbFe(MoO_{4})_{2}

We observe a disappearance of the 1/3 magnetization plateau and a striking change of the magnetic configuration under a moderate doping of the model triangular antiferromagnet RbFe(MoO_{4})_{2}. The reason is an effective lifting of degeneracy of mean-field ground states by a random potential of impurities, which compensates, in the low-temperature limit, the fluctuation contribution to free energy. These results provide a direct experimental confirmation of the fluctuation origin of the ground state in a real frustrated system. The change of the ground state to a least collinear configuration reveals an effective positive biquadratic exchange provided by the structural disorder. On heating, doped samples regain the structure of a pure compound, thus allowing for an investigation of the remarkable competition between thermal and structural disorder.

Ferroelectricity by Bose-Einstein condensation in a quantum magnet

The Bose–Einstein condensation is a fascinating phenomenon, which results from quantum statistics for identical particles with an integer spin. Surprising properties, such as superfluidity, vortex quantization or Josephson effect, appear owing to the macroscopic quantum coherence, which spontaneously develops in Bose–Einstein condensates. Realization of Bose–Einstein condensation is not restricted in fluids like liquid helium, a superconducting phase of paired electrons in a metal and laser-cooled dilute alkali atoms. Bosonic quasi-particles like exciton-polariton and magnon in solids-state systems can also undergo Bose–Einstein condensation in certain conditions. Here, we report that the quantum coherence in Bose–Einstein condensate of the magnon quasi particles yields spontaneous electric polarization in the quantum magnet TlCuCl₃, leading to remarkable magnetoelectric effect. Very soft ferroelectricity is realized as a consequence of the O(2) symmetry breaking by magnon Bose–Einstein condensation. The finding of this ferroelectricity will open a new window to explore multi-functionality of quantum magnets.

Magnons, quantized spin excitations in magnetic materials, may undergo Bose-Einstein condensation into a macroscopic correlated quantum state at low temperature. Here, the authors demonstrate how magnon condensation in quantum magnet TlCuCl₃ generates an electrical polarization.

An in vitro-in silico interface platform for spatiotemporal analysis of pattern formation in collective epithelial cells

A multicellular organization is a complex resulting from the coordinated migration of cells to form a specific pattern. The directionality of migration is governed by the mechanical and molecular dynamics of factors secreted from the cells. The mechanism underlying pattern formation is too complex to unveil by culture experiments alone. A mathematical model could provide a powerful tool for elucidating the mechanism of pattern formation by computing the molecular dynamics, which are difficult to visualize by culture experiments. However, there tends to be a gap between mathematical models and experimental research due to incongruity between the idealized conditions of the model and the experimental results. This paper presents an in vitro-in silico interface platform for elucidating the logic of multicellular pattern formation. Two-dimensional collective cell pattern formation was developed using normal human bronchial epithelial cells. Then, geometrical control of collective cells followed by feedback iteration was used to bridge the gap between the mathematical model and in vitro experiments. The mechanisms underlying the pattern formation of bronchial epithelial cells were evaluated using a reaction-diffusion model. The results indicated that differences in the diffusion rates of the activator and inhibitor determine the direction of collective cell migration to form a specific pattern.

Parry Romberg Syndrome: 7 Cases and Literature Review

Parry Romberg syndrome is a rare progressive hemiatrophy of the face that typically occurs in children and young adults and has a peculiar progression that ceases without apparent cause after a highly variable period. Only a subset of patients with Parry Romberg syndrome will develop secondary neurologic or ophthalmologic symptoms, and prognosis is highly variable. Inconsistency in the pattern of atrophy and the development of associated symptoms in patients with Parry Romberg syndrome has made it challenging to diagnose, prognosticate, and treat. The precise etiology of this disease remains unknown, but some authors have implicated sympathetic cervical ganglion dysfunction, abnormal embryogenesis, autoimmune and inflammatory mechanisms, or vasculopathy as potential causes. We present 7 cases of Parry Romberg syndrome and their associated clinical and imaging findings with specific attention to the radiographic characteristics of this disease.

Age-Related Changes in Pharyngeal Lumen Size: A Retrospective MRI Analysis

Age-related loss of muscle bulk and strength (sarcopenia) is often cited as a potential mechanism underlying age-related changes in swallowing. Our goal was to explore this phenomenon in the pharynx, specifically, by measuring pharyngeal wall thickness and pharyngeal lumen area in a sample of young versus older women. MRI scans of the neck were retrospectively reviewed from 60 women equally stratified into three age groups (20s, 60s, 70+). Four de-identified slices were extracted per scan for randomized, blinded analysis: one mid-sagittal and three axial slices were selected at the anterior inferior border of C2 and C3, and at the pit of the vallecula. Pixel-based measures of pharyngeal wall thickness and pharyngeal lumen area were completed using ImageJ and then converted to metric units. Measures of pharyngeal wall thickness and pharyngeal lumen area were compared between age groups with one-way ANOVAs using Sidak adjustments for post-hoc pairwise comparisons. A significant main effect for age was observed across all variables whereby pharyngeal wall thickness decreased and pharyngeal lumen area increased with advancing age. Pairwise comparisons revealed significant differences between 20s versus 70+ for all variables and 20s versus 60s for all variables except those measured at C2. Effect sizes ranged from 0.54 to 1.34. Consistent with existing sacropenia literature, the pharyngeal muscles appear to atrophy with age and consequently, the size of the pharyngeal lumen increases.

An 85-year old male with levodopa-responsive parkinsonism followed by dementia and supranuclear ophthalmoplegia caused by alzheimer-type pathology without Lewy bodies

An 85-year-old man developed l-dopa responsive parkinsonism indistinguishable from Parkinson's disease and subsequent dementia, followed by supranuclear ophthalmoplegia and neck dorsiflexion at the terminal stage. Midbrain tegmentum and medial temporal lobe were atrophic on magnetic resonance imaging, while decreased blood flow was predominant in frontotemporal lobes, detected by 3D-SSP of 123I- IMP SPECT. Alzheimer-type pathology without Lewy body pathology was confirmed at autopsy. Substantia nigra showed mild degeneration and several neurofibrillary tangles without Lewy body pathology or progressive supranuclear palsy cytopathology. L-dopa responsive parkinsonism could be an initial manifestation of Alzheimer's disease, which should be included in the differential diagnosis.

Measurements of the neutron activation cross sections for Bi and Co at 386 MeV

Neutron activation cross sections for Bi and Co at 386 MeV were measured by activation method. A quasi-monoenergetic neutron beam was produced using the (7)Li(p,n) reaction. The energy spectrum of these neutrons has a high-energy peak (386 MeV) and a low-energy tail. Two neutron beams, 0° and 25° from the proton beam axis, were used for sample irradiation, enabling a correction for the contribution of the low-energy neutrons. The neutron-induced activation cross sections were estimated by subtracting the reaction rates of irradiated samples for 25° irradiation from those of 0° irradiation. The measured cross sections were compared with the findings of other studies, evaluated in relation to nuclear data files and the calculated data by Particle and Heavy Ion Transport code System code.