Nanoscale density fluctuations in swift heavy ion irradiated amorphous SiO2

We report on the observation of nanoscale density fluctuations in 2 μm thick amorphous SiO₂ layers irradiated with 185 MeV Au ions. At high fluences, in excess of approximately 5 × 10¹² ions/cm², where the surface is completely covered by ion tracks, synchrotron small angle x-ray scattering measurements reveal the existence of a steady state of density fluctuations. In agreement with molecular dynamics simulations, this steady state is consistent with an ion track “annihilation” process, where high-density regions generated in the periphery of new tracks fill in low-density regions located at the center of existing tracks.The authors acknowledge the Australian Research Council and the Australian Synchrotron Research Program for financial support and thank the staff at the ANU Heavy Ion facility for their continued technical assistance. O.P., F.D., and K.N. acknowledge financial support from the Academy of Finland under its Centre of Excellence program as well as the OPNA project, and grants of computer capacity from CSC

High-resolution scanning force microscopy of gold nanoclusters on the KBr (001) surface

In this study we use a combination of dynamic scanning force microscopy experiments and first-principles simulations to study the imaging process of gold nanoclusters adsorbed on the (001) surface of KBr. In previous experiments atomic resolution was readily obtained on the KBr substrate. However, it was not possible to resolve atoms within the clusters themselves. This correlates with imaging simulations we present here using several different probable tip models: measurable contrast was readily achieved on the KBr surface and on the gold (001) surface, but simulations on the clusters demonstrated poor contrast for all tips. We further consider the role of cluster charging in the tip-surface interaction, and the role that surface defects play in the properties of adsorbed clusters.Peer reviewe

Atomic dynamics in evaporative cooling of trapped alkali atoms in strong magnetic fields

We investigate how the nonlinearity of the Zeeman shift for strong magnetic fields affects the dynamics of rf field induced evaporative cooling in magnetic traps. We demonstrate for the 87-Rb and 23-Na F=2 trapping states with wave packet simulations how the cooling stops when the rf field frequency goes below a certain limit (for the 85-Rb F=2 trapping state the problem does not appear). We examine the applicability of semiclassical models for the strong field case as an extension of our previous work [Phys. Rev. A 58, 3983 (1998)]. Our results verify many of the aspects observed in a recent $^{87}$Rb experiment [Phys. Rev. A 60, R1759 (1999)].Comment: 9 pages, RevTex, eps figures embedde

Revision rate of reconstructions in surgically treated diaphyseal metastases of bone

Introduction: Skeletal metastases can weaken the bone, necessitating surgery, and surgical treatment options vary. The aim of this study was to investigate the revision rate of reconstructions in surgically treated diaphyseal skeletal metastases. Materials and methods: Between 2000 and 2018 at Helsinki and Tampere university hospitals in Finland, a total of 164 cases with diaphyseal skeletal metastases were identified from a prospectively maintained database. Tumor location was humerus, femur, and tibia in 106 (65%), 53 (32%), and 5 (3.0%) cases, respectively. A total of 82 (50%) cases were treated with intramedullary nailing (IMN), 73 (45%) with IMN and cementation, and 9 (5%) with another technique. Results: In the upper extremity, implant survival (IS) was 96.4% at 1, 2, and 5 years; in the lower extremity, it was 83.8%, 69.1%, and 57.6% at 1, 2, and 5 years, respectively. Lower extremity IS for impending lesions was 100% at 1, 2, and 5 years, and in cases operated for true pathologic fracture, it was 71.6%, 42.9%, and 21.5% at 1, 2, and 5 years, respectively. In IMN cases without cement, the complication rate was 16% (13/82) when compared to 6% (4/73) in IMN cases with cementation. Discussion: We would advocate for early intervention in patients with metastatic bone disease affecting the femur rather that watchful waiting with the risk for fracture and the need for urgent intervention. However, this choice must be balanced against the underlying risk of surgical intervention in a potentially fragile population with often limited prognoses.Peer reviewe

Shape coexistence at the proton drip-line: First identification of excited states in 180Pb

Excited states in the extremely neutron-deficient nucleus, 180Pb, have been identified for the first time using the JUROGAM II array in conjunction with the RITU recoil separator at the Accelerator Laboratory of the University of Jyvaskyla. This study lies at the limit of what is presently achievable with in-beam spectroscopy, with an estimated cross-section of only 10 nb for the 92Mo(90Zr,2n)180Pb reaction. A continuation of the trend observed in 182Pb and 184Pb is seen, where the prolate minimum continues to rise beyond the N=104 mid-shell with respect to the spherical ground state. Beyond mean-field calculations are in reasonable correspondence with the trends deduced from experiment.Comment: 5 pages, 4 figures, submitted to Phys.Rev.

Long-term surgical and patient-reported outcomes of Hirschsprung Disease

Background: Information is needed regarding the complex relationships between long-term functional outcomes and health-related quality of life (HRQoL) in Hirschsprung's Disease (HSCR). We describe longterm outcomes across multiple domains, completing a core outcome set through to adulthood. Methods: HSCR patients operated at a single center over a 35-year period (1978-2013) were studied. Patients completed detailed questionnaires on bowel and urologic function, and HRQOL. Patients with learning disability (LD) were excluded. Outcomes were compared to normative data. Data are reported as median [IQR] or mean (SD). Results: 186 patients (median age 28 [18-32] years; 135 males) completed surveys. Bowel function was reduced (BFS 17 [14-19] vs. 19 [19-20], p < 0.0001;eta(2) = 0.22). Prevalence and severity of fecal soiling and fecal awareness improved with age ( p < 0.05 for both). Urinary incontinence was more frequent than controls, most of all in 13-26y females (65% vs. 31%, p = 0.003). In adults, this correlated independently with constipation symptoms (OR 3.18 [1.4-7.5], p = 0.008). HRQoL outcomes strongly correlated with functional outcome: 42% of children demonstrated clinically significant reductions in overall PedsQL score, and poor bowel outcome was strongly associated with impaired QOL (B = 22.7 [12.7- 32.7], p < 0.001). In adults, GIQLI scores were more often impacted in patients with extended segment disease. SF-36 scores were reduced relative to population level data in most domains, with large effect sizes noted for females in General Health (g = 1.19) and Social Wellbeing (g = 0.8). Conclusion: Functional impairment is common after pull-through, but bowel function improves with age. Clustering of poor functional outcomes across multiple domains identifies a need for early recognition and long-term support for these patients. (C) 2021 Elsevier Inc. All rights reserved.Peer reviewe

Tracks and voids in amorphous Ge induced by swift heavy-ion irradiation

Ion tracks formed in amorphous Ge by swift heavy-ion irradiation have been identified with experiment and modeling to yield unambiguous evidence of tracks in an amorphous semiconductor. Their underdense core and overdense shell result from quenched-in ra

Mouse testis development and function are differently regulated by follicle-stimulating hormone receptors signaling during fetal and prepubertal life

It is currently admitted that Follicle-Stimulating Hormone (FSH) is physiologically involved in the development and function of fetal/neonatal Sertoli cells in the rat but not the mouse. However, FSH is produced by both species from late fetal life onwards. We thus reinvestigated the role of FSH in mouse testis development at day 0 (birth) 6, 8 and 10 post-partum (dpp) by using mice that lack functional FSH receptors (FSH-R(-/-)). At birth, the number and proliferative index of Sertoli cells were significantly lower in FSH-R(-/-) mice than in wild type neonates. Claudin 11 mRNA expression also was significantly reduced in FSH-R(-/-) testes at 0 and 8 dpp, whereas the mRNA levels of other Sertoli cell markers (Transferrin and Desert hedgehog) were comparable in FSH-R(-/-) and wild type testes. Conversely, AMH mRNA and protein levels were higher at birth, comparable at 6 dpp and then significantly lower in FSH-R(-/-) testes at 8-10 dpp in FSH-R(-/-) mice than in controls. Although the plasma concentration of LH and the number of Leydig cells were similar in FSH-R(-/-) and control (wild type), testosterone concentration and P450c17 mRNA expression were significantly increased in FSH-R(-/-) testes at birth. Conversely, at 10 dpp when adult Leydig cells appear, expression of the steroidogenic genes P450scc, P450c17 and StAR was lower in FSH-R(-/-) testes than in controls. In conclusion, our results show that 1) like in the rat, signaling via FSH-R controls Sertoli cell development and function during late fetal life in the mouse as well; 2) paracrine factors produced by Sertoli cells are involved in the FSH-R-dependent regulation of the functions of fetal Leydig cells in late fetal life; and 3) the role of FSH-R signaling changes during the prepubertal period