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Gadolinium oxyorthosilicate (GSO),with its high density, high effective Z, fast decay time, and good performance at high temperature, is the scintillation detector of choice for a new generation of neutron-induced, inelastic gamma-ray spectroscopy tools for borehole measurements, specifically aimed at measuring the carbon and oxygen content from the region surrounding the borehole. The ratio of the carbon and oxygen gamma-ray yields are transformed into formation oil saturation. Because of the high energies of the carbon and oxygen gamma rays, 4.4 and 6.1 MeV, respectively, lower density and lower Z detectors cannot provide satisfactory results in small diameter tools. To get the maximum benefit from GSO, the data acquisition, choice of materials, and measurement geometry were optimized for small tool size and crystal characteristics. The large neutron cross section of the gadolinium in the scintillation crystal, its second decay constant, and the desired precision of the oil saturation measurement had important consequences in the tool design.

In the oil field, exploration of the subsurface through well logging provides measurements of the characteristics of rock formations and fluids to help identify and evaluate potential reservoirs. Downhole nuclear measurements focus on formation properties such as natural radioactivity, formation density, and hydrogen content, as well as the identification of the elemental and mineralogical composition of the rock through spectroscopy. Accurate nuclear modeling is a fundamental part of nuclear well logging tool development, from concept through design to response characterization. Underlying the accuracy of nuclear modeling is a good knowledge of nuclear cross sections of the elements in the tool, borehole, and subsurface formations. The recent focus on replacing tools based on radio-isotopic sources with those based on D-T neutron generators opens many opportunities for new measurements but highlights the deficiencies of current cross sections. For example, in neutron-induced inelastic and capture gamma ray spectroscopy, major obstacles come from a lack of or inaccuracies in the cross sections of essential materials.

Oil↓eld service companies help identify and assess reserves and future production for oil and gas reservoirs, by providing petrophysical information on rock formations. Some parameters of interest are the fraction of pore space in the rock, the quantity of oil or gas contained in the pores, the lithology or composition of the rock matrix, and the ease with which 'uids 'ow through the rock, i.e. its permeability. Downhole logging tools acquire various measurements based on electromagnetic, acoustic, magnetic resonance and nuclear physics to determine properties of the subsurface formation surrounding the wellbore. This introduction to nuclear measurements applied in the oil and gas industry reviews the most advanced nuclear measurements currently in use, including capture and inelastic gamma ray spectroscopy, neutron-gamma density, thermal neutron capture cross section, natural gamma ray, gamma-gamma density, and neutron porosity. A brief description of the technical challenges associated with deploying nuclear technology in the extreme environmental conditions of an oil well is also presented.

When designing nuclear tools for oil exploration, one of the first steps is typically nuclear modeling for concept evaluation and initial characterization. Having an accurate model, including the availability of accurate cross sections, is essential to reduce or avoid time consuming and costly design iterations. During tool response characterization, modeling is benchmarked with experimental data and then used to complement and to expand the database to make it more detailed and inclusive of more measurement environments which are difficult or impossible to reproduce in the laboratory. We present comparisons of our modeling results obtained using the ENDF/B-VI and ENDF/B-VII cross section data bases, focusing on the response to a few elements found in the tool, borehole and subsurface formation. For neutron-induced inelastic and capture gamma ray spectroscopy, major obstacles may be caused by missing or inaccurate cross sections for essential materials. We show examples of the benchmarking of modeling results against experimental data obtained during tool characterization and discuss observed discrepancies.

Introduction: Current treatment guidelines for patients with severe TBI (sTBI) are aimed at preventing secondary brain injury targeting specific endpoints of intracranial physiology to avoid the development of metabolic crisis. We sought to identify factors contributing to development of metabolic crisis in the setting of a Multi-modality Monitoring and Goal-Directed Therapy (MM&GDTP) approach to patients with severe TBI., Methods: Prospective monitoring of sTBI patients was performed, with retrospective data analysis. MM&GDTP was targeted to intracranial pressure (ICP) ≤ 20 mmHg, cerebral perfusion pressure (CPP) ≥ 60 mmHg, brain tissue oxygen pressure (PbtO 2 ) ≥ 20 mmHg, and cerebral oxygen extraction measured by bi-frontal Near infrared Spectroscopy (NIRS) > 55%. Brain flow abnormality was defined by one of the following combinations: CPP < 60 mmHg with NIRS < 55% (Type 1), CPP < 60 mmHg with PbtO 2  < 20 mmHg (Type 2), or PbtO 2  < 20 mmHg with NIRS < 55% (Type 3). Cerebral micro-dialysate was analyzed hourly for glucose, lactate, pyruvate, glutamate, glycerol, and lactate/pyruvate ratio (LPR). Statistical analysis was performed with student t-test, chi-square and Pearson's tests as applicable., Results: A total of 109,474 consecutive minutes of recorded multimodality monitoring was available for analysis. There was a significant difference in the number of minutes of brain flow abnormalities between survivors and non-survivors: 0.8% (875) versus 7.49% (8,199), respectively (p < 0.05). The duration of Type 1-3 flow abnormality per patient was higher in non-survivors (5.7 ± 2.5 h) compared to survivors (0.7 ± 0.6 h) as well as the duration of metabolic crisis, namely, 5.2 ± 2.2 versus 0.6 ± 1.0 h per patient. The occurrence of severe metabolic crisis was associated with a Type 2 flow abnormality (CPP < 60 mmHg and PbtO 2  < 20 mmHg), r = 0.97, p < 0.001, but not with Type 1 and 3., Conclusions: Metabolic crisis can occur despite a MM&GDTP approach aimed at optimizing cerebral blood flow. Severe metabolic crisis is associated to failure to maintain CPP and PbtO 2 above 60 and 20 mmHg, respectively . The occurrence of severe metabolic crisis portends a poor prognosis in patients with sTBI., (© 2020. Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: The aim of this study was to identify risk factors for morbidity and mortality in patients with rib fractures with focus on identifying a more exact age-dependent cut-off for increased morbidity and mortality., Methods: Retrospective study of patients 16 years or older with rib fractures from blunt trauma., Exclusion Criteria: patients undergoing rib plating. Initial chest X-ray and Computed Tomography (CT) scans were re-read for the number of rib fractures (NRF) and presence of pulmonary contusion (PC). Data included demographics, mechanism of injury (MOI), NRF, associated injuries, Injury Severity Score (ISS), Glasgow Coma Scale (GCS), Geriatric Trauma Outcome Score (GTOS), presence of pneumothorax, hemothorax, hemo-pneumothorax, PC, Adult Respiratory Distress Syndrome (ARDS), pulmonary complications (ventilator-associated pneumonia, nosocomial pneumonia), and mortality. PC was quantified from CT scans with Mimics. Continuous data were analyzed using Student's t test. Variables significantly different by univariate analysis were analyzed by logistic regression analysis., Results: The study group consisted of 1188 adult trauma patients admitted during a 2-year period; 800 males and 388 females, with a mean age of 54 ± 21. MOI: MVC, 735 (61.8%); falls, 364 (30.6%); other: 89. Mean NRF, 4 ± 2; GCS, GTOS, and ISS, 15 (15-15), 101 (82-124), and 19 ± 9, respectively. Incidence of PC was 329 (27.7%); PTX, HTX, and HTX/PTX, 264 (20.2%), 57 (4.8%), and 147 (12.4%). Flail chest, in 17 (1.4%); 321 required mechanical ventilation. Age, GCS, male gender, and ISS but not NRF and/or PC were predictive of mortality., Conclusions: Increased mortality in patients with rib fractures starts at 65 years of age without a further increase until age ≥ 80. NRF does not predict increased mortality independent of age. Severe TBI is the most common cause of death in patients 16-75 years, as opposed to respiratory complications in patients 80 years-old or greater., (© 2019. Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Breast cancer is a hypercoagulable state and predisposes patients to venous thromboembolism (VTE). We sought to determine independent risk factors for VTE post-surgical treatment for breast cancer using a national risk adjusted database., Methods: Participant Use Data Files in the National Surgical Quality Improvement Program database from 2012 to 2016 were studied. Female patients with invasive and in situ breast cancer that underwent either mastectomy with immediate breast reconstruction, autologous or implant-based, or lumpectomy were identified with current procedural terminology and International Classification of Diseases-9 codes. Venous thromboembolism was defined as occurrence of deep vein thrombosis or pulmonary embolism. Non-VTE and VTE groups were compared and statistical differences were addressed through propensity score weighting. The balance of the model was checked with comparing standardized differences before and after weighting. Multivariate logistic regression was used to determine independent predictors of VTE., Results: A total of 137 449 procedures were identified. After applying exclusion criteria, 40 986 lumpectomies and 35 909 mastectomies remained for the analysis (n = 76 895). Venous thromboembolism was found in 172/76 895 patients (0.2%). In the weighted data set, mastectomy, BMI> 35 and length of stay >3 days were predictors of VTE. The greatest odds ratio (OR) was observed with mastectomy with immediate autologous breast reconstruction (OR = 8.792, P < .001; 95% CI: 3.618-21.367)., Conclusion: Autologous breast reconstruction was associated with highest risk of VTE. Hospital LOS >3 days, BMI >35, and general anesthesia also increase odds of developing VTE. These variables are predisposing factors that need to be considered in patients undergoing surgical treatment for breast cancer., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© 2020 The Author(s).)

Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor of the alimentary tract and usually presents with gastrointestinal hemorrhage. The diagnosis of GIST is typically made with upper endoscopy after excluding other causes of bleeding. The surgical management of GIST can be challenging depending upon the location of the tumor. We present a unique case of duodenal GIST in the setting von Willebrand's disease diagnosed after emergent laparotomy for massive gastrointestinal hemorrhage. Key strategies in curing our patient were treating the underlying bleeding disorder, collaborating with radiology and gastroenterology teams, and early exploratory laparotomy for refractory hemorrhage. This case demonstrates the challenges of diagnosing and managing GIST in patients with underlying coagulopathies., (Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author(s) 2020.)

Background: Direct transport of patients with severe traumatic brain injury (sTBI) to trauma centers (TCs) that can provide definitive care results in lower mortality rates. This study investigated the impact of direct versus nondirect transfers on the mortality rates of patients with sTBI., Methods: Data on patients with TBI admitted between January 1, 2012, and December 31, 2013, to our Level I TC were obtained from the trauma registry. Data included patient age, sex, mechanism, and type of injury, comorbidities, Glasgow Coma Scale, Injury Severity scores, prehospital time, time to request and to transfer, time to initiation of multimodality monitoring and goal-directed therapy protocol, dwell time in the emergency department (EDT), and mortality. Data, reported in means ± standard deviation, were analyzed with the Student t-test and chi-square. Statistical significance was accepted at a P value < 0.05., Results: sTBI direct transfer to TC versus transfer from non-TCs (NTC): Of the 1187 patients with TBI admitted to our TC, 768 (64.7%) were admitted directly from the scene, whereas 419 (35.3%) were admitted after secondary transfer. One hundred seventy-one (22.2%) of the direct transfers had Glasgow Coma Scale < 8 (sTBI) and 92 (21.9%) of the secondary transfers had sTBI. The transfer time: Time from scene to arrival to the EDT was significantly shorter for TC versus NTCs 43 ± 14 versus 77 ± 26 min, respectively (P < 0.05). EDT dwell time before transfer and time from injury to arrival to TC were 4.2 ± 2.1 and 6.2 ± 8.3 h, respectively. Mortality: There was a statistically significant lower mortality for patients with sTBI transferred directly from the scene to TCs as opposed to patients secondarily transferred, 33/171 (19.3%) versus 33/92 (35.8%), respectively (P < 0.05)., Conclusions: To decrease TBI-related mortality, patients with suspected sTBI should be taken directly to a Level I or II TC unless they require life-saving stabilization at NTCs., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Multimodality monitoring and goal-directed therapy may not prevent blood flow and brain oxygen (Flow/BrOx) crisis. We sought to determine the impact of these events on outcome in patients with severe traumatic brain injury (sTBI)., Methods: Twenty-four patients with sTBI were treated to maintain intracranial pressure (ICP) less than or equal to 20 mm Hg, cerebral perfusion pressure (CPP) greater than or equal to 60 mm Hg, brain oxygen greater than or equal to 20 mm Hg, and near infrared spectroscopy greater than or equal to 60%. Flow/BrOx crisis events were recorded. The 14-day predicted mortality was compared with actual mortality., Results: Nonsurvivors had a significantly higher number of crisis events nonresponsive to treatment (P < .05). Mortality was 87.5% in patients with greater than or equal to 20 events versus 6.3% in patients with less than 20 events. The predicted mortality was 58%, whereas actual mortality was 33.3% (8/24), yielding a 42% reduction in mortality., Conclusions: A multimodality monitoring and goal-directed therapy may decrease mortality in sTBI. However, Flow/BrOx crisis events still occur and predict a poor outcome., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Long-term effects, especially the incidence of tumors, of whole-body exposure of female NMRI mice with either negative pions (peak or plateau region) or X rays have been studied in comparison to controls. Animals were irradiated at the age of 10 days after birth. The mice were then regularly examined for deaths and signs of severe disease, moribund animals being killed. A detailed histopathological work-up has been performed. The data show that the survival as defined by death or the time of autopsy is significantly lower in irradiated mice in comparison to controls, that there is no difference in reduction of survival between groups treated either with X rays or pions at peak region, but that a difference can be seen when comparing X rays with pions at plateau region. The incidence of ovarian tumors at any particular age is higher in mice treated with X rays or pions than in control groups, but significantly lower in animals exposed to plateau pions than in those treated with peak pions or X rays.

The computed tomographic (CT) findings in 23 patients with complicated cholecystitis verified at surgery in 20 cases or autopsy in three cases were analyzed. Gallbladder size, wall thickness, and bile density as determined by CT are nonspecific. Gallstones as the leading diagnostic sign are difficult to identify by CT. Pericholecystitis, inflammatory lesions, and, particularly, abscess formation indicating complications of cholecystitis are readily demonstrated by CT.