bluuebunny/crossref_metadata_2025_split huggingface dataset:
CFD analyses of the rod bowing effect on the subchannel outlet temperature distribution
Authors: Ekström K. , Toppila T. 
Published: September 2017

Abstract
In the Loviisa 1 and 2 nuclear power plants the subcooling margin of the hottest subchannel of the fuel assembly is monitored. The temperature of the coolant in the hottest subchannel is limited to the constant saturation temperature. Bending of the fuel rods occurs during normal operation due to the differences in the heat profiles of the rods. The coolant temperature will rise more in the subchannel with smaller flow area due to the bending and this has to be taken into account in the safety margin of subchannel enthalpy rise. Computational Fluid Dynamics (CFD) simulations are used to estimate how much the estimated maximum bow of a rod affects the temperature rise of the subchannel. The quantitative uncertainty of the predicted enthalpy rise in fuel bundle subchannel is estimated based on the uncertainty of modelling of mixing between subchannels. The measured turbulence quantities from LDA measurements of cold test assembly made in 1990s in Fortum are compared with CFD results to give uncertainty estimation for turbulence, which is further used for uncertainty estimation of mixing and simulated subchannel enthalpy rise.
Study on the impact of transition from 3-batch to 4-batch loading at Loviisa NPP on the long-term decay heat and activity inventory
Authors: Lahtinen T. 
Published: September 2017

Abstract
The fuel economy of Loviisa NPP was improved by implementing a transition from 3-batch to 4-batch loading scheme between 2009 and 2013. Equilibrium cycle length as well as all process parameters were retained unchanged while the increase of fuel enrichment enabled to reduce the annual reload batch size from 102 to 84 assemblies. The fuel cycle transition obviously had an effect on the long-term decay heat and activity inventory. However, due to simultaneous change in several quantities the net effect over the relevant cooling time region is not self-evident. In this study the effect is analyzed properly, i. e. applying consistent calculation models and detailed description of assembly-wise irradiation histories. The study concludes that for the cooling time, foreseen typical prior to encapsulation of assemblies, the decay heat of discharge batch increases 2 – 3%. It is also concluded that, in order to maintain 100% filling degree of final disposal canisters, the cooling time prior to encapsulation needs to be prolonged by 10 – 15 years.
Verification results of methodology for determining the weighted mean coolant temperature in the primary circuit hot legs of WWER-1000 reactor plants
Authors: Saunin Yu. V. , Dobrotvorski A. N. , Semenikhin A. V. , Korolev A. S. , Ryasny S. I. 
Published: September 2017

Abstract
The JSC “Atomtechenergo” experts have developed a new methodology for determining the weighted mean coolant temperature in the primary circuit hot legs of WWER-1000 reactor plants. The necessity for developing the new methodology was determined by the need to decrease the calculation error of the weighted mean coolant temperature in the hot legs because of the coolant temperature stratification. The methodology development was based on the findings of experimental and calculating research executed by the authors. The methodology verification was fulfilled through comparison of calculation results obtained with and without the methodology use in various operational states and modes of several WWER-1000 power units. The obtained verification results have confirmed that the use of the new methodology provides objective error decrease in determining the weighted mean coolant temperature in the primary circuit hot legs. The decrease value depends on the stratification character which is various for different objects and conditions.
Phase equilibria in the Zr–Si–B ternary system (Zr–Si–ZrB2 region) at 1 173 K
Authors: Han Feng , Zhan Yongzhong , Luo Hao 
Published: September 2017

Abstract
The isothermal section of the Zr–Si–B ternary system (Zr–Si–ZrB2 region) at 1 173 K has been experimentally determined. All equilibrated alloys were characterized via X-ray powder diffraction and scanning electron microscopy equipped with energy-dispersive X-ray analysis. A ternary phase Zr5(Si0.86B0.14)3 was found at 1 173 K. The experimental results show that the isothermal section consists of 11 single-phase regions, 26 two-phase regions and 13 three-phase regions. The existence of eight compounds, i. e. ZrSi2, ZrSi, Zr5Si4, Zr3Si2, Zr2Si, ZrB, ZrB2 and Zr5(Si0.86B0.14)3 in this system has been confirmed in the Zr–Si–ZrB2 region at 1 173 K.
Outcomes of stereotactic radiosurgery for foramen magnum meningiomas: an international multicenter study
Authors: Mehta Gautam U. , Zenonos Georgios , Patibandla Mohana Rao , Lin Chung Jung , Wolf Amparo , Grills Inga , Mathieu David , McShane Brendan , Lee John Y. , Blas Kevin , Kondziolka Douglas , Lee Cheng-Chia , Lunsford L. Dade , Sheehan Jason P. 
Published: September 2017

OBJECTIVEMeningiomas are the most common benign extramedullary lesions of the foramen magnum; however, their optimal management remains undefined. Given their location, foramen magnum meningiomas (FMMs) can cause significant morbidity, and complete microsurgical removal can be challenging. Anterior and anterolateral FMMs carry greater risks with surgery, but they comprise the majority of these lesions. As an alternative to resection, stereotactic radiosurgery (SRS) has been used to treat FMMs in small case series. To more clearly define the outcomes of SRS and to delineate a rational management paradigm for these lesions, the authors analyzed the safety and efficacy of SRS for FMM in an international multicenter trial.METHODSSeven medical centers participating in the International Gamma Knife Research Foundation (IGKRF) provided data for this retrospective cohort study. Patients who were treated with Gamma Knife radiosurgery and whose clinical and radiological follow-up was longer than 6 months were eligible for study inclusion. Data from pre- and post-SRS radiological and clinical evaluations were analyzed. Stereotactic radiosurgery treatment variables were recorded.RESULTSFifty-seven patients (39 females and 18 males, with a median age of 64 years) met the study inclusion criteria. Thirty-two percent had undergone prior microsurgical resection. Patients most frequently presented with cranial neuropathy (39%), headache (35%), numbness (32%), and ataxia (30%). Median pre-SRS tumor volume was 2.9 cm3. Median SRS margin dose was 12.5 Gy (range 10–16 Gy). At the last follow-up after SRS, 49% of tumors were stable, 44% had regressed, and 7% had progressed. Progression-free survival rates at 5 and 10 years were each 92%. A greater margin dose was associated with a significantly increased likelihood of tumor regression, with 53% of tumors treated with > 12 Gy regressing. Fifty-two percent of symptomatic patients noted some clinical improvement. Adverse radiation effects were limited to hearing loss and numbness in 1 patient (2%).CONCLUSIONSStereotactic radiosurgery for FMM frequently results in tumor control or tumor regression, as well as symptom improvement. Margin doses > 12 Gy were associated with increased rates of tumor regression. Stereotactic radiosurgery was generally safe and well tolerated. Given its risk-benefit profile, SRS may be particularly useful in the management of small- to moderate-volume anterior and anterolateral FMMs.
Angioarchitecture of arteriovenous fistulas at the craniocervical junction: a multicenter cohort study of 54 patients
Authors: Hiramatsu Masafumi , Sugiu Kenji , Ishiguro Tomoya , Kiyosue Hiro , Sato Kenichi , Takai Keisuke , Niimi Yasunari , Matsumaru Yuji 
Published: September 2017

OBJECTIVEThe aim of this retrospective multicenter cohort study was to assess the details of the angioarchitecture of arteriovenous fistulas (AVFs) at the craniocervical junction (CCJ) and to determine the associations between the angiographic characteristics and the clinical presentations and outcomes.METHODSThe authors analyzed angiographic and clinical data for patients with CCJ AVFs from 20 participating centers that are members of the Japanese Society for Neuroendovascular Therapy (JSNET). Angiographic findings (feeding artery, location of AV shunt, draining vein) and patient data (age, sex, presentation, treatment modality, outcome) were tabulated and stratified based on the angiographic types of the lesions, as diagnosed by a member of the CCJ AVF study group, which consisted of a panel of 6 neurointerventionalists and 1 spine neurosurgeon.RESULTSThe study included 54 patients (median age 65 years, interquartile range 61–75 years) with a total of 59 lesions. Five angiographic types were found among the 59 lesions: Type 1, dural AVF (22 [37%] of 59); Type 2, radicular AVF (17 [29%] of 59); Type 3, epidural AVF (EDAVF) with pial feeders (8 [14%] of 59); Type 4, EDAVF (6 [10%] of 59); and Type 5, perimedullary AVF (6 [10%] of 59). In almost all lesions (98%), AV shunts were fed by radiculomeningeal arteries from the vertebral artery that drained into intradural or epidural veins through AV shunts on the dura mater, on the spinal nerves, in the epidural space, or on the spinal cord. In more than half of the lesions (63%), the AV shunts were also fed by a spinal pial artery from the anterior spinal artery (ASA) and/or the lateral spinal artery. The data also showed that the angiographic characteristics associated with hemorrhagic presentations—the most common presentation of the lesions (73%)—were the inclusion of the ASA as a feeder, the presence of aneurysmal dilatation on the feeder, and CCJ AVF Type 2 (radicular AVF). Treatment outcomes differed among the angiographic types of the lesions.CONCLUSIONSCraniocervical junction AVFs commonly present with hemorrhage and are frequently fed by both radiculomeningeal and spinal pial arteries. The AV shunt develops along the C-1 or C-2 nerve roots and can be located on the spinal cord, on the spinal nerves, and/or on the inner or outer surface of the dura mater.
Voxel-based lesion mapping of meningioma: a comprehensive lesion location mapping of 260 lesions
Authors: Hirayama Ryuichi , Kinoshita Manabu , Arita Hideyuki , Kagawa Naoki , Kishima Haruhiko , Hashimoto Naoya , Fujimoto Yasunori , Yoshimine Toshiki 
Published: September 2017

OBJECTIVEIn the present study the authors aimed to determine preferred locations of meningiomas by avoiding descriptive analysis and instead using voxel-based lesion mapping and 3D image-rendering techniques.METHODSMagnetic resonance images obtained in 248 treatment-naïve meningioma patients with 260 lesions were retrospectively and consecutively collected. All images were registered to a 1-mm isotropic, high-resolution, T1-weighted brain atlas provided by the Montreal Neurological Institute (the MNI152), and a lesion frequency map was created, followed by 3D volume rendering to visualize the preferred locations of meningiomas in 3D.RESULTSThe 3D lesion frequency map clearly showed that skull base structures such as parasellar, sphenoid wing, and petroclival regions were commonly affected by the tumor. The middle one-third of the superior sagittal sinus was most commonly affected in parasagittal tumors. Substantial lesion accumulation was observed around the leptomeninges covering the central sulcus and the sylvian fissure, with very few lesions observed at the frontal, parietal, and occipital convexities.CONCLUSIONSUsing an objective visualization method, meningiomas were shown to be located around the middle third of the superior sagittal sinus, the perisylvian convexity, and the skull base. These observations, which are in line with previous descriptive analyses, justify further use of voxel-based lesion mapping techniques to help understand the biological nature of this disease.
Utility of intraoperative rotational thromboelastometry in thoracolumbar deformity surgery
Authors: Guan Jian , Cole Chad D. , Schmidt Meic H. , Dailey Andrew T. 
Published: September 2017

OBJECTIVEBlood loss during surgery for thoracolumbar scoliosis often requires blood product transfusion. Rotational thromboelastometry (ROTEM) has enabled the more targeted treatment of coagulopathy, but its use in deformity surgery has received limited study. The authors investigated whether the use of ROTEM reduces transfusion requirements in this case-control study of thoracolumbar deformity surgery.METHODSData were prospectively collected on all patients who received ROTEM-guided blood product management during long-segment (≥ 7 levels) posterior thoracolumbar fusion procedures at a single institution from April 2015 to February 2016. Patients were matched with a group of historical controls who did not receive ROTEM-guided therapy according to age, fusion segments, number of osteotomies, and number of interbody fusion levels. Demographic, intraoperative, and postoperative transfusion requirements were collected on all patients. Univariate analysis of ROTEM status and multiple linear regression analysis of the factors associated with total in-hospital transfusion volume were performed, with p < 0.05 considered to indicate statistical significance.RESULTSFifteen patients who received ROTEM-guided therapy were identified and matched with 15 non-ROTEM controls. The mean number of fusion levels was 11 among all patients, with no significant differences between groups in terms of fusion levels, osteotomy levels, interbody fusion levels, or other demographic factors. Patients in the non-ROTEM group required significantly more total blood products during their hospitalization than patients in the ROTEM group (8.5 ± 4.2 units vs 3.71 ± 2.8 units; p = 0.001). Multiple linear regression analysis showed that the use of ROTEM (p = 0.016) and a lower number of fused levels (p = 0.022) were associated with lower in-hospital transfusion volumes.CONCLUSIONSROTEM use during thoracolumbar deformity correction is associated with lower transfusion requirements. Further investigation will better define the role of ROTEM in transfusion during deformity surgery.
Topectomy versus leukotomy: J. Lawrence Pool’s contribution to psychosurgery
Authors: Holland Ryan , Kopel David , Carmel Peter W. , Prestigiacomo Charles J. 
Published: September 2017

Surgery of the mind has a rather checkered past. Though its history begins with the prehistoric trephination of skulls to allow “evil spirits” to escape, the early- to mid-20th century saw a surge in the popularity of psychosurgery. The 2 prevailing operations were topectomy and leukotomy for the treatment of certain mental illnesses. Although they were modified and refined by several of their main practitioners, the effectiveness of and the ethics involved with these operations remained controversial.In 1947, Dr. J. Lawrence Pool and the Columbia-Greystone Associates sought to rigorously investigate the outcomes of specific psychosurgical procedures. Pool along with R. G. Heath and John Weber believed that nonexcessive bifrontal cortical ablation could successfully treat certain mental illnesses without the undesired consequences of irreversible personality changes. They conducted this investigation at the psychiatric hospital at Greystone Park near Morristown, New Jersey.Despite several encouraging findings of the Columbia-Greystone project, psychosurgery practices began to decline significantly in the 1950s. The uncertainty of results and ethical debates related to side effects made these procedures unpopular. Further, groups such as the National Association for the Advancement of Colored People and the American Civil Liberties Union condemned the use of psychosurgery, believing it to be an inhumane form of treatment. Today, there are strict guidelines that must be adhered to when evaluating a patient for psychosurgery procedures. It is imperative for the neurosurgery community to remember the history of psychosurgery to provide the best possible current treatment and to search for better future treatments for a particularly vulnerable patient population.
Optimal stimulation parameters for intraoperative bulbocavernosus reflex in infants
Authors: Hwang Hyeoncheol , Wang Kyu-Chang , Bang Moon Suk , Shin Hyung-Ik , Kim Seung-Ki , Phi Ji Hoon , Lee Ji Yeoun , Choi Jinwoo , Cha Seungwoo , Kim Keewon 
Published: September 2017

OBJECTIVEThe aim of this study was to establish optimal electric stimulation parameters for intraoperatively monitoring the bulbocavernosus reflexes (BCRs) in infants.METHODSThe authors retrospectively reviewed the medical records of all infants (age < 24 months) who had undergone an untethering operation for tethered cord syndrome between May 2013 and February 2014 at a single institution and whose baseline BCR had been elicited during surgery. Using different combinations of stimulation parameters—number of stimulation pulses: 4 or 8 pulses, interpulse interval: 1, 2, or 5 msec, and polarity of stimulation: biphasic or monophasic—the authors compared the relative mean amplitude of 10 BCR responses (rmaBCRs) to each combination of parameters.RESULTSThe rmaBCRs were larger with the 8-pulse stimulations than with the 4-pulse stimulations (p < 0.0001). There was a tendency, though not statistically significant, for larger rmaBCRs to be obtained with the longer interpulse interval in the 8-pulse stimulation (p = 0.1289). The biphasic stimulation produced larger rmaBCRs than the monophasic stimulation (p = 0.0005).CONCLUSIONSBiphasic 8-pulse stimulations with 5-msec or 2-msec intervals yield the largest BCR responses. Considering that an 8-pulse stimulation with 5-msec intervals may overlap the onset of the BCR, a biphasic 8-pulse stimulation with 2-msec intervals is recommended as the optimal stimulation paradigm to monitor intraoperative BCRs in infants.
Decrease in grip and knee extension strength with age in American women
Authors: Bohannon Richard W. 
Published: September 2017

OBJECTIVE: To describe and compare decreases in grip and knee extension strength accompanying aging. METHOD: Eighty-five community-dwelling women (20 to 79 years of age) participating in the validation phase of the NIH Toolbox for the Assessment of Neurological and Behavioral Function contributed data to this study. Their strength was measured bilaterally-grip with a hand dynamometer and isometric knee extension with an isokinetic dynamometer. Grip and knee extension strength measures of the left and right sides were combined and analyzed. RESULTS: Both combined grip strength and combined knee extension strength decreased with age. The decreases were significant between the 60–79 year age group and the 20–39 year age group. Strength of the 60–79 year age group, described as a percentage of the 20–39 year age group, was significantly less for knee extension than for grip. CONCLUSION: Grip strength declines less than knee extension strength with age. Grip strength, therefore, may not fully capture the effect of age on muscle strength.
Risk Factors, Neuroanatomical Correlates, and Outcome of Neuropsychiatric Symptoms in Alzheimer’s Disease
Authors: Poulin Stéphane P. , Bergeron David , Dickerson Bradford C. ,   for the Alzheimer’s Disease Neuroimaging Initiative
Published: September 2017

Background: An integrative model of neuropsychiatric symptoms (NPS) in Alzheimer’s disease (AD) is lacking. Objective: In this study, we investigated the risk factors, anatomy, biology, and outcomes of NPS in AD. Methods: 181 subjects were included from the Alzheimer’s Disease Neuroimaging Study (ADNI). NPS were assessed with the Neuropsychiatric Inventory Questionnaire at baseline and 6 months. NPI >3 was used as a threshold for NPS positivity. Three NPS courses were characterized: 1) minimal/absent (negative at 0 and 6 months, n = 77); 2) fluctuating (positive only at one time point, n = 53); 3) persistent (positive at both time points, n = 51). We examined the association between NPS course and family history of dementia, personal history of psychiatric disorders, cerebrospinal fluid biomarkers, atrophy patterns, as well as longitudinal cognitive and functional measures at 12 and 24 months (MMSE, CDR-SOB, FAQ). Results: AD subjects with absent, fluctuating, or persistent NPS had similar CSF amyloid-β and tau levels. AD subjects with minimal/absent NPS had less personal history of psychiatric disorders (35%) than those with fluctuating (57%; p = 0.015) or persistent NPS (47%, not significant). At 24 months, AD subjects with persistent NPS had worse cognitive (MMSE; p = 0.05) and functional (CDR-SOB; p = 0.016) outcomes. Dorsolateral prefrontal atrophy was seen in persistent NPS, but not in fluctuating NPS. Conclusions: Our results suggest that individuals with personal history of psychiatric disorders might be more vulnerable to develop NPS throughout the course of AD. The worst cognitive and functional outcomes associated with NPS in AD underscores the importance of monitoring NPS early in the disease course.
Association of Gait Speed, Psychomotor Speed, and Dementia
Authors: Kuate-Tegueu Callixte , Avila-Funes José-Alberto , Simo Nadine , Le Goff Mélanie , Amiéva Hélène , Dartigues Jean-François , Tabue-Teguo Maturin 
Published: September 2017

Background: Gait speed (GS) and psychomotor speed (PS) could be considered as two different dimensions of age-related slowness and both measures are associated with higher risk of adverse health-related outcomes among elderly people. Objective: To determine the association between GS, PS, and incident dementia among community-dwelling older adults. Methods: Twelve-year longitudinal study of 1,265 participants in the Bordeaux Three-City Study, a French prospective cohort designed to determine the risk of dementia and cognitive impairment attributable to cardiovascular risk factors. Participants completed a battery of cognitive tests, including time to complete the Trail Making Test A, and a walking speed test. The incidence of dementia was determined over the 12-year follow-up period. Cox proportional hazards models with delayed entry were used to estimate the cumulative risk of dementia and were adjusted for sex, education, and ApoE4 genotype. Results: Mean age of participants was 74.0 years (SD 4.8). Over the 12-year follow-up, 203 participants developed dementia. GS and PS were both independent predictors of incident all-cause dementia after 12 years of follow-up. For a one SD increase of either GS or PS, the hazard ratio (HR) for Alzheimer’s disease was 1.2 (95% CI = 1.02–1.32) and 1.4 (95% CI = 1.2–1.61), respectively; whereas for incident vascular dementia, the HR was 1.3 (95% CI = 1.05–1.71) and 1.5 (95% CI = 1.16–2.08), respectively. No significant interaction between GS and PS was observed. Conclusions: In older French people aged 65+, our findings showed that both low GS and PS were independently associated with risk of incident Alzheimer’s disease and vascular dementia.