Brainstem blood brain barrier disruption using focused ultrasound: A demonstration of feasibility and enhanced doxorubicin delivery.

PubMed

Alli, Saira; Figueiredo, Carlyn A; Golbourn, Brian; Sabha, Nesrin; Wu, Megan Yijun; Bondoc, Andrew; Luck, Amanda; Coluccia, Daniel; Maslink, Colin; Smith, Christian; Wurdak, Heiko; Hynynen, Kullervo; O'Reilly, Meaghan; Rutka, James T

2018-05-15

Magnetic Resonance Image-guided Focused Ultrasound (MRgFUS) has been used to achieve transient blood brain barrier (BBB) opening without tissue injury. Delivery of a targeted ultrasonic wave causes an interaction between administered microbubbles and the capillary bed resulting in enhanced vessel permeability. The use of MRgFUS in the brainstem has not previously been shown but could provide value in the treatment of tumours such as Diffuse Intrinsic Pontine Glioma (DIPG) where the intact BBB has contributed to the limited success of chemotherapy. Our primary objective was to determine whether the use of MRgFUS in this eloquent brain region could be performed without histological injury and functional deficits. Our secondary objective was to select an effective chemotherapeutic against patient derived DIPG cell lines and demonstrate enhanced brainstem delivery when combined with MRgFUS in vivo. Female Sprague Dawley rats were randomised to one of four groups: 1) Microbubble administration but no MRgFUS treatment; 2) MRgFUS only; 3) MRgFUS + microbubbles; and 4) MRgFUS + microbubbles + cisplatin. Physiological assessment was performed by monitoring of heart and respiratory rates. Motor function and co-ordination were evaluated by Rotarod and grip strength testing. Histological analysis for haemorrhage (H&E), neuronal nuclei (NeuN) and apoptosis (cleaved Caspase-3) was also performed. A drug screen of eight chemotherapy agents was conducted in three patient-derived DIPG cell lines (SU-DIPG IV, SU-DIPG XIII and SU-DIPG XVII). Doxorubicin was identified as an effective agent. NOD/SCID/GAMMA (NSG) mice were subsequently administered with 5 mg/kg of intravenous doxorubicin at the time of one of the following: 1) Microbubbles but no MRgFUS; 2) MRgFUS only; 3) MRgFUS + microbubbles and 4) no intervention. Brain specimens were extracted at 2 h and doxorubicin quantification was conducted using liquid chromatography mass spectrometry (LC/MS). BBB opening was confirmed by contrast enhancement on T1-weighted MR imaging and positive Evans blue staining of the brainstem. Normal cardiorespiratory parameters were preserved. Grip strength and Rotarod testing demonstrating no decline in performance across all groups. Histological analysis showed no evidence of haemorrhage, neuronal loss or increased apoptosis. Doxorubicin demonstrated cytotoxicity against all three cell lines and is known to have poor BBB permeability. Quantities measured in the brainstem of NSG mice were highest in the group receiving MRgFUS and microbubbles (431.5 ng/g). This was significantly higher than in mice who received no intervention (7.6 ng/g). Our data demonstrates both the preservation of histological and functional integrity of the brainstem following MRgFUS for BBB opening and the ability to significantly enhance drug delivery to the region, giving promise to the treatment of brainstem-specific conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

MR-guided focused ultrasound surgery, present and future

PubMed Central

Schlesinger, David; Benedict, Stanley; Diederich, Chris; Gedroyc, Wladyslaw; Klibanov, Alexander; Larner, James

2013-01-01

MR-guided focused ultrasound surgery (MRgFUS) is a quickly developing technology with potential applications across a spectrum of indications traditionally within the domain of radiation oncology. Especially for applications where focal treatment is the preferred technique (for example, radiosurgery), MRgFUS has the potential to be a disruptive technology that could shift traditional patterns of care. While currently cleared in the United States for the noninvasive treatment of uterine fibroids and bone metastases, a wide range of clinical trials are currently underway, and the number of publications describing advances in MRgFUS is increasing. However, for MRgFUS to make the transition from a research curiosity to a clinical standard of care, a variety of challenges, technical, financial, clinical, and practical, must be overcome. This installment of the Vision 20/20 series examines the current status of MRgFUS, focusing on the hurdles the technology faces before it can cross over from a research technique to a standard fixture in the clinic. It then reviews current and near-term technical developments which may overcome these hurdles and allow MRgFUS to break through into clinical practice. PMID:23927296

A software tool for advanced MRgFUS prostate therapy planning and follow up

NASA Astrophysics Data System (ADS)

van Straaten, Dörte; Hoogenboom, Martijn; van Amerongen, Martinus J.; Weiler, Florian; Issawi, Jumana Al; Günther, Matthias; Fütterer, Jurgen; Jenne, Jürgen W.

2017-03-01

US guided HIFU/FUS ablation for the therapy of prostate cancer is a clinical established method, while MR guided HIFU/FUS applications for prostate recently started clinical evaluation. Even if MRI examination is an excellent diagnostic tool for prostate cancer, it is a time consuming procedure and not practicable within an MRgFUS therapy session. The aim of our ongoing work is to develop software to support therapy planning and post-therapy follow-up for MRgFUS on localized prostate cancer, based on multi-parametric MR protocols. The clinical workflow of diagnosis, therapy and follow-up of MR guided FUS on prostate cancer was deeply analyzed. Based on this, the image processing workflow was designed and all necessary components, e.g. GUI, viewer, registration tools etc. were defined and implemented. The software bases on MeVisLab with several implemented C++ modules for the image processing tasks. The developed software, called LTC (Local Therapy Control) will register and visualize automatically all images (T1w, T2w, DWI etc.) and ADC or perfusion maps gained from the diagnostic MRI session. This maximum of diagnostic information helps to segment all necessary ROIs, e.g. the tumor, for therapy planning. Final therapy planning will be performed based on these segmentation data in the following MRgFUS therapy session. In addition, the developed software should help to evaluate the therapy success, by synchronization and display of pre-therapeutic, therapy and follow-up image data including the therapy plan and thermal dose information. In this ongoing project, the first stand-alone prototype was completed and will be clinically evaluated.

TU-B-210-01: MRg HIFU - Bone and Soft Tissue Tumor Ablation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghanouni, P.

MR guided focused ultrasound (MRgFUS), or alternatively high-intensity focused ultrasound (MRgHIFU), is approved for thermal ablative treatment of uterine fibroids and pain palliation in bone metastases. Ablation of malignant tumors is under active investigation in sites such as breast, prostate, brain, liver, kidney, pancreas, and soft tissue. Hyperthermia therapy with MRgFUS is also feasible, and may be used in conjunction with radiotherapy and for local targeted drug delivery. MRI allows in situ target definition and provides continuous temperature monitoring and subsequent thermal dose mapping during HIFU. Although MRgHIFU can be very precise, treatment of mobile organs is challenging and advancedmore » techniques are required because of artifacts in MR temperature mapping, the need for intercostal firing, and need for gated HIFU or tracking of the lesion in real time. The first invited talk, “MR guided Focused Ultrasound Treatment of Tumors in Bone and Soft Tissue”, will summarize the treatment protocol and review results from treatment of bone tumors. In addition, efforts to extend this technology to treat both benign and malignant soft tissue tumors of the extremities will be presented. The second invited talk, “MRI guided High Intensity Focused Ultrasound – Advanced Approaches for Ablation and Hyperthermia”, will provide an overview of techniques that are in or near clinical trials for thermal ablation and hyperthermia, with an emphasis of applications in abdominal organs and breast, including methods for MRTI and tracking targets in moving organs. Learning Objectives: Learn background on devices and techniques for MR guided HIFU for cancer therapy Understand issues and current status of clinical MRg HIFU Understand strategies for compensating for organ movement during MRgHIFU Understand strategies for strategies for delivering hyperthermia with MRgHIFU CM - research collaboration with Philips.« less

TU-B-210-02: MRg HIFU - Advanced Approaches for Ablation and Hyperthermia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moonen, C.

2015-06-15

MR guided focused ultrasound (MRgFUS), or alternatively high-intensity focused ultrasound (MRgHIFU), is approved for thermal ablative treatment of uterine fibroids and pain palliation in bone metastases. Ablation of malignant tumors is under active investigation in sites such as breast, prostate, brain, liver, kidney, pancreas, and soft tissue. Hyperthermia therapy with MRgFUS is also feasible, and may be used in conjunction with radiotherapy and for local targeted drug delivery. MRI allows in situ target definition and provides continuous temperature monitoring and subsequent thermal dose mapping during HIFU. Although MRgHIFU can be very precise, treatment of mobile organs is challenging and advancedmore » techniques are required because of artifacts in MR temperature mapping, the need for intercostal firing, and need for gated HIFU or tracking of the lesion in real time. The first invited talk, “MR guided Focused Ultrasound Treatment of Tumors in Bone and Soft Tissue”, will summarize the treatment protocol and review results from treatment of bone tumors. In addition, efforts to extend this technology to treat both benign and malignant soft tissue tumors of the extremities will be presented. The second invited talk, “MRI guided High Intensity Focused Ultrasound – Advanced Approaches for Ablation and Hyperthermia”, will provide an overview of techniques that are in or near clinical trials for thermal ablation and hyperthermia, with an emphasis of applications in abdominal organs and breast, including methods for MRTI and tracking targets in moving organs. Learning Objectives: Learn background on devices and techniques for MR guided HIFU for cancer therapy Understand issues and current status of clinical MRg HIFU Understand strategies for compensating for organ movement during MRgHIFU Understand strategies for strategies for delivering hyperthermia with MRgHIFU CM - research collaboration with Philips.« less

Agar-Silica-Gel Heating Phantom May Be Suitable for Long-Term Quality Assurance of MRgHIFU

NASA Astrophysics Data System (ADS)

Partanen, Ari

2009-04-01

In MRgHIFU, the purpose of frequent quality assurance is to detect changes in system performance to prevent adverse effects during treatments. Due to high ultrasound intensities in MRgHIFU, it is essential to assure that the procedure is safe and efficacious and that image-based guidance of the treatment is reliable. We aimed to develop a guideline for MRgHIFU QA by acquiring MR temperature maps during ultrasonic heating of an agar-silica-gel phantom over a four month-period using three separate MRgHIFU uterine leiomyoma treatment systems. From this data, the stability of the maximum temperature elevation, the targeting accuracy, and the dimensions of the heated volume were analyzed. Additionally, we studied the sensitivity of these parameters to reveal hypothetical decrease in HIFU performance. After calibration, the mean targeting offsets of the heated volume were observed to be less than 2 mm in the three orthogonal directions. The measured maximum temperature elevation and the length and the width of the heated volume remained consistent throughout the four-month period. Furthermore, it was found that the parameters under investigation were sensitive to reveal the decreased HIFU performance. We conclude that an agar-silica -based phantom is suitable for targeting accuracy and heating properties QA of MRgHIFU system even in long-term use. Moreover, this simple QA method may be used to reveal small changes in HIFU performance assuring consistent functionality and safety of the MRgHIFU system.

Moment analysis method as applied to the 2S --> 2P transition in cryogenic alkali metal/rare gas matrices.

PubMed

Terrill Vosbein, Heidi A; Boatz, Jerry A; Kenney, John W

2005-12-22

The moment analysis method (MA) has been tested for the case of 2S --> 2P ([core]ns1 --> [core]np1) transitions of alkali metal atoms (M) doped into cryogenic rare gas (Rg) matrices using theoretically validated simulations. Theoretical/computational M/Rg system models are constructed with precisely defined parameters that closely mimic known M/Rg systems. Monte Carlo (MC) techniques are then employed to generate simulated absorption and magnetic circular dichroism (MCD) spectra of the 2S --> 2P M/Rg transition to which the MA method can be applied with the goal of seeing how effective the MA method is in re-extracting the M/Rg system parameters from these known simulated systems. The MA method is summarized in general, and an assessment is made of the use of the MA method in the rigid shift approximation typically used to evaluate M/Rg systems. The MC-MCD simulation technique is summarized, and validating evidence is presented. The simulation results and the assumptions used in applying MA to M/Rg systems are evaluated. The simulation results on Na/Ar demonstrate that the MA method does successfully re-extract the 2P spin-orbit coupling constant and Landé g-factor values initially used to build the simulations. However, assigning physical significance to the cubic and noncubic Jahn-Teller (JT) vibrational mode parameters in cryogenic M/Rg systems is not supported.

Workflow and intervention times of MR-guided focused ultrasound - Predicting the impact of new techniques.

PubMed

Loeve, Arjo J; Al-Issawi, Jumana; Fernandez-Gutiérrez, Fabiola; Langø, Thomas; Strehlow, Jan; Haase, Sabrina; Matzko, Matthias; Napoli, Alessandro; Melzer, Andreas; Dankelman, Jenny

2016-04-01

Magnetic resonance guided focused ultrasound surgery (MRgFUS) has become an attractive, non-invasive treatment for benign and malignant tumours, and offers specific benefits for poorly accessible locations in the liver. However, the presence of the ribcage and the occurrence of liver motion due to respiration limit the applicability MRgFUS. Several techniques are being developed to address these issues or to decrease treatment times in other ways. However, the potential benefit of such improvements has not been quantified. In this research, the detailed workflow of current MRgFUS procedures was determined qualitatively and quantitatively by using observation studies on uterine MRgFUS interventions, and the bottlenecks in MRgFUS were identified. A validated simulation model based on discrete events simulation was developed to quantitatively predict the effect of new technological developments on the intervention duration of MRgFUS on the liver. During the observation studies, the duration and occurrence frequencies of all actions and decisions in the MRgFUS workflow were registered, as were the occurrence frequencies of motion detections and intervention halts. The observation results show that current MRgFUS uterine interventions take on average 213min. Organ motion was detected on average 2.9 times per intervention, of which on average 1.0 actually caused a need for rework. Nevertheless, these motion occurrences and the actions required to continue after their detection consumed on average 11% and up to 29% of the total intervention duration. The simulation results suggest that, depending on the motion occurrence frequency, the addition of new technology to automate currently manual MRgFUS tasks and motion compensation could potentially reduce the intervention durations by 98.4% (from 256h 5min to 4h 4min) in the case of 90% motion occurrence, and with 24% (from 5h 19min to 4h 2min) in the case of no motion. In conclusion, new tools were developed to predict how intervention durations will be affected by future workflow changes and by the introduction of new technology. Copyright © 2016 Elsevier Inc. All rights reserved.

Influence of QBO on stratospheric Kelvin and Mixed Rossby gravity waves in high-top CMIP5 models

NASA Astrophysics Data System (ADS)

Indah Solihah, Karina; Lubis, Sandro W.; Setiawan, Sonni

2018-05-01

It is well established that quasi-biennial oscillation (QBO) has a substantial influence on Kelvin and mixed Rossby gravity (MRG) wave activity in the tropical lower stratosphere. In this study, we examined how QBO influences Kelvin and MRG wave activity in the lower stratosphere, based on nine high-top CMIP5 models. The results show that the Kelvin and MRG wave signals are stronger in the models with QBO, and relatively weaker in the models without QBO. The results are consistent with established theory, whereby upward-propagating Kelvin waves occurs more frequently during the easterly QBO phase, while upward-propagating MRG waves occurs during the westerly QBO phase. Without the QBO, the mean flow exhibits a near-zero easterly wind, which prevents the waves from propagating and penetrating into the stratosphere. Our analysis also shows that models with the QBO tend to have more robust signatures (in terms of amplitude and phase speed) of Kelvin and MRG waves.

MR guided FUS therapy with a Robotic Assistance System

NASA Astrophysics Data System (ADS)

Jenne, Jürgen W.; Krafft, Axel J.; Maier, Florian; Rauschenberg, Jaane; Semmler, Wolfhard; Huber, Peter E.; Bock, Michael

2009-04-01

Magnetic Resonance imaging guided Focus Ultrasound Surgery (MRgFUS) is a highly precise method to ablate tissue non-invasively. To date, there is only one commercial MRgFUS system available and only a few are in a prototype stage. The objective of this ongoing project is to establish an MRgFUS therapy unit as add-on for a commercially available robotic assistance system originally designed for percutaneous needle interventions in whole-body MR scanners.

MRI-Guided Focused Ultrasound Surgery for Uterine Fibroid Treatment: A Cost-Effectiveness Analysis

PubMed Central

Kong, Chung Y.; Omer, Zehra B.; Pandharipande, Pari V.; Swan, J. Shannon; Srouji, Serene; Gazelle, G. Scott; Fennessy, Fiona M.

2015-01-01

Objective To evaluate the cost-effectiveness of a treatment strategy for symptomatic uterine fibroids that employs Magnetic Resonance guided Focused Ultrasound (MRgFUS) as a first-line therapy relative to uterine artery embolization (UAE) or abdominal hysterectomy (HYST). Materials and Methods We developed a decision-analytic model to compare the cost-effectiveness of three treatment strategies: MRgFUS, UAE and HYST. Short and long-term utilities specific to each treatment were incorporated, allowing us to account for differences in quality of life across the strategies considered. Lifetime costs and quality-adjusted life-years (QALYs) were calculated for each strategy. An incremental cost-effectiveness analysis was performed, using a societal willingness-to-pay (WTP) threshold of $50,000 per QALY to designate a strategy as cost-effective. Sensitivity analysis was performed on all key model parameters. Results In the base-case analysis, in which treatment for symptomatic fibroids started at age 40, UAE was the most effective and expensive strategy (22.81 QALYs, $22,164), followed by MRgFUS (22.80 QALYs, $19,796) and HYST (22.60 QALYs, $13,291). MRgFUS was cost-effective relative to HYST, with an associated incremental cost-effectiveness ratio (ICER) of $33,110/QALY. MRgFUS was also cost-effective relative to UAE – the ICER of UAE relative to MRgFUS ($270,057) far exceeded the WTP threshold of $50,000/QALY. In sensitivity analysis, results were robust to changes in most parameters, but were sensitive to changes in probabilities of recurrence and symptom relief following certain procedures, and quality of life associated with symptomatic fibroids. Conclusions MRgFUS is cost-effective relative to both UAE and hysterectomy for the treatment of women with symptomatic fibroids. PMID:25055272

TU-B-210-00: MR-Guided Focused Ultrasound Therapy in Oncology

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

MR guided focused ultrasound (MRgFUS), or alternatively high-intensity focused ultrasound (MRgHIFU), is approved for thermal ablative treatment of uterine fibroids and pain palliation in bone metastases. Ablation of malignant tumors is under active investigation in sites such as breast, prostate, brain, liver, kidney, pancreas, and soft tissue. Hyperthermia therapy with MRgFUS is also feasible, and may be used in conjunction with radiotherapy and for local targeted drug delivery. MRI allows in situ target definition and provides continuous temperature monitoring and subsequent thermal dose mapping during HIFU. Although MRgHIFU can be very precise, treatment of mobile organs is challenging and advancedmore » techniques are required because of artifacts in MR temperature mapping, the need for intercostal firing, and need for gated HIFU or tracking of the lesion in real time. The first invited talk, “MR guided Focused Ultrasound Treatment of Tumors in Bone and Soft Tissue”, will summarize the treatment protocol and review results from treatment of bone tumors. In addition, efforts to extend this technology to treat both benign and malignant soft tissue tumors of the extremities will be presented. The second invited talk, “MRI guided High Intensity Focused Ultrasound – Advanced Approaches for Ablation and Hyperthermia”, will provide an overview of techniques that are in or near clinical trials for thermal ablation and hyperthermia, with an emphasis of applications in abdominal organs and breast, including methods for MRTI and tracking targets in moving organs. Learning Objectives: Learn background on devices and techniques for MR guided HIFU for cancer therapy Understand issues and current status of clinical MRg HIFU Understand strategies for compensating for organ movement during MRgHIFU Understand strategies for strategies for delivering hyperthermia with MRgHIFU CM - research collaboration with Philips.« less

Cranial nerve threshold for thermal injury induced by MRI-guided high-intensity focused ultrasound (MRgHIFU): preliminary results on an optic nerve model.

PubMed

Harnof, Sagi; Zibly, Zion; Cohen, Zvi; Shaw, Andrew; Schlaff, Cody; Kassel, Neal F

2013-04-01

Future clinical applications of magnetic resonance imaging-guided high-intensity focused ultrasound (MRgHIFU) are moving toward the management of different intracranial pathologies. We sought to validate the production, safety, and efficacy of thermal injury to cranial nerves generated by MRgHIFU. In this study, five female domestic pigs underwent a standard bifrontal craniectomy under general anesthesia. Treatment was then given using an MRgHIFU system to induce hyperthermic ablative sonication (6 to 10 s; 50 to 2000 J.) Histological analyses were done to confirm nerve damage; temperature measured on the optic nerve was approximately 53.4°C (range: 39°C to 70°C.) Histology demonstrated a clear definition between a necrotic, transitional zone, and normal tissue. MRgHIFU induces targeted thermal injury to nervous tissue within a specific threshold of 50°C to 60°C with the tissue near the sonication center yielding the greatest effect; adjacent tissue showed minimal changes. Additional studies utilizing this technology are required to further establish accurate threshold parameters for optic nerve thermo-ablation.

Magnetic Resonance Guided Focused Ultrasound Surgery: Part 2 – A Review of Current and Future Applications

PubMed Central

Medel, Ricky; Monteith, Stephen J.; Elias, W. Jeffrey; Eames, Matthew; Snell, John; Sheehan, Jason P.; Wintermark, Max; Jolesz, Ferenc A.; Kassell, Neal F.

2014-01-01

Magnetic Resonance guided Focused Ultrasound Surgery (MRgFUS) represents a novel combination of technologies that is actively being realized as a non-invasive therapeutic tool for a myriad of conditions. These applications are reviewed with a focus on neurological utilization. A combined search of Pubmed and Medline was performed to identify the key events and current status of MRgFUS, with a focus on neurological applications. MRgFUS signifies a potentially ideal device for the treatment of neurological diseases. As it is nearly real-time, it allows monitored provision of treatment location and energy deposition, is noninvasive, thereby limiting or eliminating disruption of normal tissue, provides focal delivery of therapeutic agents, enhances radiation delivery, and permits modulation of neural function. Multiple clinical applications are currently in clinical use and many more are under active preclinical investigation. The therapeutic potential of MRgFUS is expanding rapidly. Although clinically in its infancy, preclinical and early phase I clinical trials in neurosurgery suggest a promising future for MRgFUS. Further investigation is necessary to define its true potential and impact. PMID:22791029

Mrg: A Magnitude Scale for 1 s Rayleigh Waves at Local Distances with Focus on Yield Estimation

DTIC Science & Technology

2016-08-23

typical of “hard” rock emplacement media. The MRg estimates using Eq. 5 are shown in Figure 3c. The network average MRg, which is estimated after...MATERIEL COMMAND KIRTLAND AIR FORCE BASE, NM 87117-5776 DTIC COPY NOTICE AND SIGNATURE PAGE Using Government drawings, specifications, or other...convey any rights or permission to manufacture, use , or sell any patented invention that may relate to them. This report was cleared for public

An 11-Channel Radio Frequency Phased Array Coil for Magnetic Resonance Guided High Intensity Focused Ultrasound of the Breast

PubMed Central

Minalga, E.; Payne, A.; Merrill, R.; Todd, N.; Vijayakumar, S.; Kholmovski, E.; Parker, D. L.; Hadley, J. R.

2012-01-01

In this study, a radio-frequency (RF) phased array coil was built to image the breast in conjunction with a Magnetic Resonance guided High Intensity Focused Ultrasound (MRgHIFU) device designed specifically to treat the breast in a treatment cylinder with reduced water volume. The MRgHIFU breast coil was comprised of a 10-channel phased array coil placed around an MRgHIFU treatment cylinder where nearest-neighbor decoupling was achieved with capacitive decoupling in a shared leg. In addition a single loop coil was placed at the chest wall making a total of 11-channels. The RF coil array design presented in this work was chosen based on ease of implementation, increased visualization into the treatment cylinder, image reconstruction speed, temporal resolution, and resulting signal-to-noise-ratio (SNR) profiles. This work presents a dedicated 11-channel coil for imaging of the breast tissue in the MRgHIFU setup without obstruction of the ultrasound beam and, specifically, compares its performance in SNR, overall imaging time, and temperature measurement accuracy to that of the standard single chest-loop coil typically used in breast MRgHIFU. PMID:22431301

MRI-guided Focused Ultrasound Ablation of Lumbar Medial Branch Nerve: Feasibility and Safety Study in a Swine Model

PubMed Central

Kaye, Elena A; Monette, Sebastien; Srimathveeravalli, Govindarajan; Maybody, Majid; Solomon, Stephen B; Gulati, Amitabh

2016-01-01

Purpose About 10–40% of chronic low back pain cases involve facet joints, which are commonly treated with lumbar medial branch (MB) radiofrequency neurotomy. Magnetic Resonance Imaging-guided Focused Ultrasound (MRgFUS), a non-invasive, non-ionizing ablation modality used to treat tumors, neuropathic pain and painful bone metastasis, can also be used to disrupt nerve conduction. This work’s purpose was to study the feasibility and safety of direct MRgFUS ablation of the lumbar MB nerve in acute and subacute swine models. Materials and Methods In vivo MRgFUS ablation was performed in six swine (3 acute and 3 subacute) using a clinical MRgFUS system (ExAblate 2000®; InSightec Ltd., Haifa, Israel) and 3 T MRI scanner (SIGNA; GE Healthcare, Waukesha, WI, USA) combination. Behavioral assessment was performed, and imaging and histology were used to assess the treatment. Results and Conclusions Histological analysis of the in vivo studies confirmed thermal necrosis of the MB nerve could be achieved without damaging the spinal cord or adjacent nerve roots. MRgFUS did not cause changes in the animals’ behavior and ambulation. PMID:27443328

DOE Office of Scientific and Technical Information (OSTI.GOV)

Froeling, V., E-mail: vera.froeling@charite.de; Meckelburg, K., E-mail: katrin.meckelburg@charite.de; Scheurig-Muenkler, C., E-mail: christian.scheurig-muenkler@charite.de

Purpose: To compare the rate of reintervention and midterm changes in symptom severity (SS) and Total health-related quality of life (HRQoL) scores after uterine artery embolization (UAE) and magnetic resonance-guided high-intensity focused ultrasound (MR-g HIFU) for symptomatic uterine fibroids. Methods: Eighty women (median age 38.3 years), equally eligible for MR-g HIFU and UAE who underwent one of both treatments between 2002 and 2009 at our institution, were included. The primary end point of the study was defined as the rate of reintervention after both therapies. The secondary outcome was defined as changes in SS and Total HRQoL scores after treatment.more » SS and Total HRQoL scores before treatment and at midterm follow-up (median 13.3 months) were assessed by the uterine fibroid symptom and quality-of-life questionnaire (UFS-QoL) and compared. Results: The rate of reintervention was significantly lower after UAE than after MR-g HIFU (p = 0.002). After both treatments, SS and Total HRQoL scores improved significantly from baseline to follow-up (UAE: p < 0.001, p < 0.001; MR-g HIFU: p = 0.002, p < 0.001). Total HRQoL scores were significantly higher after UAE than after MR-g HIFU (p = 0.032). Changes in the SS scores did not differ significantly for both treatments (p = 0.061). Conclusion: UAE and MR-g HIFU significantly improved the health-related quality of life of women with symptomatic uterine fibroids. After UAE, the change in Total HRQoL score improvement was significantly better, and a significantly lower rate of reintervention was observed.« less

Magnetic resonance-guided focused ultrasound surgery for treatment of painful osseous metastases

NASA Astrophysics Data System (ADS)

Hurwitz, Mark; Machtinger, Ronit; Fennessy, Fiona

2011-03-01

Magnetic resonance guided focused ultrasound surgery (MRgFUS) is an emerging technology that can non-invasively heat and ablate targeted tissue utilizing ultrasound energy. Use of MR imaging for treatment guidance provides several key advantages over more widely used ultrasound guidance for focused ultrasound ablation. MR allows for precise targeting, detailed beam path visualization, real time non-invasive temperature measurement, and treatment feedback to ensure therapeutic goals are achieved. In the realm of oncology, management of painful bone metastases is a common and daunting clinical problem. The Insightec ExAblate System has been shown in phase I/II trials for treatment of bone metastases to have an excellent safety profile and high rates of pain response. An international multi-center phase III trial for patients with painful bone metastases or multiple myeloma who are not candidates for radiation therapy is currently open. Patients are randomized 3:1 to MRgFUS or sham treatment with crossover to study treatment allowed for sham failures. The primary study endpoint is assessment of pain control over 3 months following treatment. In addition safety, quality of life, cost effectiveness analysis, and patient perceived clinical benefit are also being assessed. Details of the MRgFUS system, technical and clinical therapeutic parameters, use of real time non-invasive MR thermometry, and examples of patient treatments with use of MRgFUS to treat bone metastases will be discussed. New directions in use of MRgFUS including an update on development of a new mobile applicator and integration of MRgFUS in multimodality oncologic care will also be presented.

Technique adaptation, strategic replanning, and team learning during implementation of MR-guided brachytherapy for cervical cancer.

PubMed

Skliarenko, Julia; Carlone, Marco; Tanderup, Kari; Han, Kathy; Beiki-Ardakani, Akbar; Borg, Jette; Chan, Kitty; Croke, Jennifer; Rink, Alexandra; Simeonov, Anna; Ujaimi, Reem; Xie, Jason; Fyles, Anthony; Milosevic, Michael

MR-guided brachytherapy (MRgBT) with interstitial needles is associated with improved outcomes in cervical cancer patients. However, there are implementation barriers, including magnetic resonance (MR) access, practitioner familiarity/comfort, and efficiency. This study explores a graded MRgBT implementation strategy that included the adaptive use of needles, strategic use of MR imaging/planning, and team learning. Twenty patients with cervical cancer were treated with high-dose-rate MRgBT (28 Gy in four fractions, two insertions, daily MR imaging/planning). A tandem/ring applicator alone was used for the first insertion in most patients. Needles were added for the second insertion based on evaluation of the initial dosimetry. An interdisciplinary expert team reviewed and discussed the MR images and treatment plans. Dosimetry-trigger technique adaptation with the addition of needles for the second insertion improved target coverage in all patients with suboptimal dosimetry initially without compromising organ-at-risk (OAR) sparing. Target and OAR planning objectives were achieved in most patients. There were small or no systematic differences in tumor or OAR dosimetry between imaging/planning once per insertion vs. daily and only small random variations. Peer review and discussion of images, contours, and plans promoted learning and process development. Technique adaptation based on the initial dosimetry is an efficient approach to implementing MRgBT while gaining comfort with the use of needles. MR imaging and planning once per insertion is safe in most patients as long as applicator shifts, and large anatomical changes are excluded. Team learning is essential to building individual and programmatic competencies. Copyright © 2017 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

Routine Pre-Treatment MRI for Breast Cancer in a Single-Payer Medical Center: Effects on Surgical Choices, Timing and Outcomes

PubMed Central

Vreeland, Timothy J; Berry IV, John S; Schneble, Erika; Jackson, Doreen O; Herbert, Garth S; Hale, Diane F; Martin, Jonathon M; Flores, Madeline; Pattyn, Adam R; Hata, Kai; Clifton, Guy T; Kirkpatrick, Aaron D; Peoples, George E.

2017-01-01

Introduction: Pre-operative MRI is being used with increasing frequency to evaluate breast cancer patients, but the debate surrounding risks and benefits of this use continues. At our institution, we instituted a standardized protocol for pre-operative MRI. Here, we compare patients seen prior to routine use of MRI to those seen after and examine effects on surgical choices, timing and outcomes. Methods: This is a retrospective review of a prospectively collected database of all new invasive breast cancers seen from January 2007 to December 2012. The control group (CG) did not receive MRI, while the MRI group (MRG) underwent MRI according to our pretreatment protocol. Groups were compared with regards to basic demographics, initial surgical choices, need for re-excision, and surgical timing. The electronic medical records of patients in the MRG who underwent mastectomy as their initial surgery were examined closely to determine the main factors leading to their choice of surgery. Finally, correlation between findings on MRI and final surgical pathology was analyzed. Results: Of 282 patients included, 38 were in the CG and 244 in the MRG; the groups were well matched. The MRG had a significantly higher percentage of patients choosing initial mastectomy (MRG: 47.1% vs CG 21.1%, p=0.003). Patients seen in the first 2 years of the study were less likely to choose mastectomy than those enrolled in the latter years (29.2%vs 48.6%, p=0.004). The MRG had a lower chance of return to the operating room for re-excision (15.2% vs 28.9%, p=0.035). The average time from initial imaging to initial surgery was approximately the same between groups (MRG: 39.7 days vs CG 42.1 days, p=0.45) and the MRG actually had shorter time to definitive (margin-negative) surgical management (MRG: 43.5 days vs CG: 50.3 days, p=0.079). One hundred-fifteen patients in the MRG underwent mastectomy as initial surgery. Of these, 64 (55.7%) had no additional findings on MRI and chose mastectomy based on patient preference; 30 patients (26.1%) (29 unilateral, 1 bilateral) had mastectomy because of MRI findings. Of the 31 breasts removed (29 unilateral and 1 bilateral mastectomies) because of MRI findings, 26 (83.9%) had histologic findings that correlated with the MRI findings, while 5 (16.1%) did not. Conclusion: Patients receiving routine pre-treatment MRI had an increased mastectomy rate, but had a lower re-excision rate. We found no delay to initial surgical therapy and, perhaps more importantly, a slight decrease in time to margin-negative surgical therapy in the MRI group. Women choosing mastectomy after MRI did so because of personal preference over half of the time, while MRI findings influenced this choice in 26% of these women. When MRI findings did lead to mastectomy, these findings were confirmed by pathology results in the vast majority of cases. PMID:28900481

Metabolism of Kaempferia parviflora polymethoxyflavones by human intestinal bacterium Bautia sp. MRG-PMF1.

PubMed

Kim, Mihyang; Kim, Nayoung; Han, Jaehong

2014-12-24

Poylmethoxyflavones (PMFs) are major bioactive flavonoids, which exhibit various biological activities, such as anticancer effects. The biotransformation of PMFs and characterization of a PMF-metabolizing human intestinal bacterium were studied herein for the first time. Hydrolysis of aryl methyl ether functional groups by human fecal samples was observed from the bioconversion of various PMFs. Activity-guided screening for PMF-metabolizing intestinal bacteria under anaerobic conditions resulted in the isolation of a strict anaerobic bacterium, which was identified as Blautia sp. MRG-PMF1. The isolated MRG-PMF1 was able to metabolize various PMFs to the corresponding demethylated flavones. The microbial conversion of bioactive 5,7-dimethoxyflavone (5,7-DMF) and 5,7,4'-trimethoxyflavone (5,7,4'-TMF) was studied in detail. 5,7-DMF and 5,7,4'-TMF were completely metabolized to 5,7-dihydroxyflavone (chrysin) and 5,7,4'-trihydroxyflavone (apigenin), respectively. From a kinetics study, the methoxy group on the flavone C-7 position was found to be preferentially hydrolyzed. 5-Methoxychrysin, the intermediate of 5,7-DMF metabolism by Blautia sp. MRG-PMF1, was isolated and characterized by nuclear magnetic resonance spectroscopy. Apigenin was produced from the sequential demethylation of 5,7,4'-TMF, via 5,4'-dimethoxy-7-hydroxyflavone and 7,4'-dihydroxy-5-methoxyflavone (thevetiaflavone). Not only demethylation activity but also deglycosylation activity was exhibited by Blautia sp. MRG-PMF1, and various flavonoids, including isoflavones, flavones, and flavanones, were found to be metabolized to the corresponding aglycones. The unprecedented PMF demethylation activity of Blautia sp. MRG-PMF1 will expand our understanding of flavonoid metabolism in the human intestine and lead to novel bioactive compounds.

MRI-Guided Focused Ultrasound Surgery

PubMed Central

Jolesz, Ferenc A.

2014-01-01

MRI-guided focused ultrasound (MRgFUS) surgery is a noninvasive thermal ablation method that uses magnetic resonance imaging (MRI) for target definition, treatment planning, and closed-loop control of energy deposition. Integrating FUS and MRI as a therapy delivery system allows us to localize, target, and monitor in real time, and thus to ablate targeted tissue without damaging normal structures. This precision makes MRgFUS an attractive alternative to surgical resection or radiation therapy of benign and malignant tumors. Already approved for the treatment of uterine fibroids, MRgFUS is in ongoing clinical trials for the treatment of breast, liver, prostate, and brain cancer and for the palliation of pain in bone metastasis. In addition to thermal ablation, FUS, with or without the use of microbubbles, can temporarily change vascular or cell membrane permeability and release or activate various compounds for targeted drug delivery or gene therapy. A disruptive technology, MRgFUS provides new therapeutic approaches and may cause major changes in patient management and several medical disciplines. PMID:19630579

Enhanced Delivery of Gold Nanoparticles with Therapeutic Potential into the Brain using MRI-Guided Focused Ultrasound

PubMed Central

Etame, Arnold B.; Diaz, Roberto J.; O’Reilly, Meaghan A.; Smith, Christian A.; Mainprize, Todd G.; Hynynen, Kullervo; Rutka, James T.

2014-01-01

The blood brain barrier (BBB) is a major impediment to the delivery of therapeutics into the central nervous system (CNS). Gold nanoparticles (AuNPs) have been successfully employed in multiple potential therapeutic and diagnostic applications outside the CNS. However, AuNPs have very limited biodistribution within the CNS following intravenous administration. Magnetic resonance imaging guided focused ultrasound (MRgFUS) is a novel technique that can transiently increase BBB permeability allowing delivery of therapeutics into the CNS. MRgFUS has not been previously employed for delivery of AuNPs into the CNS. This work represents the first demonstration of focal enhanced delivery of AuNPs into the CNS using MRgFUS in a rat model both safely and effectively. Histologic visualization and analytical quantification of AuNPs within the brain parenchyma suggest BBB transgression. These results suggest a role for MRgFUS in the delivery of AuNPs with therapeutic potential into the CNS for targeting neurological diseases. PMID:22349099

How feasible is remote 3D dosimetry for MR guided Radiation Therapy (MRgRT)?

NASA Astrophysics Data System (ADS)

Mein, S.; Rankine, L.; Miles, D.; Juang, T.; Cai, B.; Curcuru, A.; Mutic, S.; Fenoli, J.; Adamovics, J.; Li, H.; Oldham, M.

2017-05-01

To develop and apply a remote dosimetry protocol with PRESAGE® radiochromic plastic and optical-CT readout in the validation of MRI guided radiation therapy (MRgRT) treatments (MRIdian® by ViewRay®). Through multi-institutional collaboration we performed PRESAGE® dosimetry studies in 4ml cuvettes to investigate dose-response linearity, MR-compatibility, and energy-independence. An open calibration field and symmetrical 3-field plans were delivered to 10cm diameter PRESAGE® to examine percent depth dose and response uniformity under a magnetic field. Evidence of non-linear dose response led to a large volume PRESAGE® study where small corrections were developed for temporally- and spatially-dependent behaviors observed between irradiation and delayed readout. TG-119 plans were created in the MRIdian® TPS and then delivered to 14.5cm 2kg PRESAGE® dosimeters. Through the domestic investigation of an off-site MRgRT system, a refined 3D remote dosimetry protocol is presented capable of validation of advanced MRgRT radiation treatments.

Evaluation of the pain and local tenderness in bone metastasis treated with magnetic resonance-guided focused ultrasound surgery (MRgFUS)

NASA Astrophysics Data System (ADS)

Namba, Hirofumi; Kawasaki, Motohiro; Kato, Tomonari; Tani, Toshikazu; Ushida, Takahiro; Koizumi, Norihiro

2017-03-01

It has been reported that MRgFUS has pain palliative effects on the local pain in patients with bone metastasis. In general, a severity of pain has been evaluated using only subjective method with numerical rating scale (NRS) or visual analogue scale (VAS). It is important to evaluate local pain-palliative effects of MRgFUS treatment with objective and quantitative method. The aim of this study is to investigate changes in the severity of local pain of bone metastasis before and after MRgFUS treatments, measuring pressure pain threshold (PPT) using pressure algometer, and pain intensity using electrical stimulation device (the Pain Vision system) at most painful site of bone metastasis. We have conducted MRgFUS for pain palliation of bone metastasis for 8 patients, and evaluated the local tenderness quantitatively for 8 patients, and evaluated local pain intensity for 7 patients. Before the treatments, PPTs were 106.3kPa [40.0-431.5] at metastatic site and 344.8 kPa [206.0-667.0] at normal control site, which showed a significant difference. The PPTs at metastatic site shows a significant increase from 106.3 kPa [40.0-431.5] at the baseline to 270.5 kPa [93.5-533.5] at 3 months after the treatment. The NRS score shows a significant decrease from 6.0 [4-8] at baseline to 1 [0-3] at 3 months after the treatment. Similarly, the pain intensity shows a significant decrease 245 [96.3-888.7] at baseline to 55.9 [2.8-292] at 3 months after the treatment. The results of our study illustrate the pain-relieving effects of MRgFUS for the treatment of painful bone metastasis. PPT might be a useful parameter not only for assessing a treatment's effect, but also for the decision of the painful area to treat with MRgFUS. Pain Vision seems to be useful for quantitative and objective evaluation of local pain of painful bone metastasis.

Neurosurgical Applications of High-Intensity Focused Ultrasound with Magnetic Resonance Thermometry.

PubMed

Colen, Rivka R; Sahnoune, Iman; Weinberg, Jeffrey S

2017-10-01

Magnetic resonance guided focused ultrasound surgery (MRgFUS) has potential noninvasive effects on targeted tissue. MRgFUS integrates MRI and focused ultrasound surgery (FUS) into a single platform. MRI enables visualization of the target tissue and monitors ultrasound-induced effects in near real-time during FUS treatment. MRgFUS may serve as an adjunct or replace invasive surgery and radiotherapy for specific conditions. Its thermal effects ablate tumors in locations involved in movement disorders and essential tremors. Its nonthermal effects increase blood-brain barrier permeability to enhance delivery of therapeutics and other molecules. Copyright © 2017 Elsevier Inc. All rights reserved.

Symptomatic improvement in uterine myomas after MRgFUS: 4 year follow up

NASA Astrophysics Data System (ADS)

Funaki, Kaoru; Fukunishi, Hidenobu

2011-09-01

Objective: To assess the long-term improvement in symptoms after magnetic resonance-guided focused ultrasound surgery (MRgFUS) for uterine myomas. Methods: Japanese women with symptomatic myomas underwent MRgFUS using the ExAblate 2000 system. The symptom severity score (SSS) was examined before and after the treatment at 3, 6, 12, 24, and 48 months. Simultaneously, we asked the patients' satisfaction level regarding the overall change of subjective symptoms: symptom free, improved a great deal, improved to some extent, no change, or worsened. The myoma volumes were measured at 6, 12, 24, 36 and 48 months after MRgFUS. Results: No severe adverse event occurred with any of the patients. The mean SSS value before treatment was 38.3±21.5 (n = 106), which diminished significantly during follow-up for 3-48 months after treatment. Patients' satisfaction level was favorable, although the response rate was low. Over 80% of the patients replied that their symptoms were improved to at least some extent, and over 50% of the patients replied that their symptoms were improved a great deal. This trend continued throughout this follow up period. The mean myoma volume was also decreased from the pretreatment volume in this follow up period. Conclusion: MRgFUS is an effective and safe method for treating symptomatic uterine myomas. Long-term symptomatic improvement is promising.

Genome-Wide Association Mapping of Barley Yellow Dwarf Virus Tolerance in Spring Oat (Avena sativa L.)

PubMed Central

Foresman, Bradley J.; Oliver, Rebekah E.; Jackson, Eric W.; Chao, Shiaoman; Arruda, Marcio P.; Kolb, Frederic L.

2016-01-01

Barley yellow dwarf viruses (BYDVs) are responsible for the disease barley yellow dwarf (BYD) and affect many cereals including oat (Avena sativa L.). Until recently, the molecular marker technology in oat has not allowed for many marker-trait association studies to determine the genetic mechanisms for tolerance. A genome-wide association study (GWAS) was performed on 428 spring oat lines using a recently developed high-density oat single nucleotide polymorphism (SNP) array as well as a SNP-based consensus map. Marker-trait associations were performed using a Q-K mixed model approach to control for population structure and relatedness. Six significant SNP-trait associations representing two QTL were found on chromosomes 3C (Mrg17) and 18D (Mrg04). This is the first report of BYDV tolerance QTL on chromosome 3C (Mrg17) and 18D (Mrg04). Haplotypes using the two QTL were evaluated and distinct classes for tolerance were identified based on the number of favorable alleles. A large number of lines carrying both favorable alleles were observed in the panel. PMID:27175781

Magnetic resonance-guided focused ultrasound treatment of facet joint pain: summary of preclinical phase

PubMed Central

2014-01-01

Study design A phantom experiment, two thermocouple experiments, three in vivo pig experiments, and a simulated treatment on a healthy human volunteer were conducted to test the feasibility, safety, and efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) for treating facet joint pain. Objective The goal of the current study was to develop a novel method for accurate and safe noninvasive facet joint ablation using MRgFUS. Summary of background data Facet joints are a common source of chronic back pain. Direct facet joint interventions include medial branch nerve ablation and intra-articular injections, which are widely used, but limited in the short and long term. MRgFUS is a breakthrough technology that enables accurate delivery of high-intensity focused ultrasound energy to create a localized temperature rise for tissue ablation, using MR guidance for treatment planning and real-time feedback. Methods We validated the feasibility, safety, and efficacy of MRgFUS for facet joint ablation using the ExAblate 2000® System (InSightec Ltd., Tirat Carmel, Israel) and confirmed the system's ability to ablate the edge of the facet joint and all terminal nerves innervating the joint. A phantom experiment, two thermocouple experiments, three in vivo pig experiments, and a simulated treatment on a healthy human volunteer were conducted. Results The experiments showed that targeting the facet joint with energies of 150–450 J provides controlled and accurate heating at the facet joint edge without penetration to the vertebral body, spinal canal, or root foramina. Treating with reduced diameter of the acoustic beam is recommended since a narrower beam improves access to the targeted areas. Conclusions MRgFUS can safely and effectively target and ablate the facet joint. These results are highly significant, given that this is the first study to demonstrate the potential of MRgFUS to treat facet joint pain. PMID:24921048

Hydraulic modeling and meander migration of the Middle Rio Grande, New Mexico

Treesearch

Michael J. Sixta

2004-01-01

The dynamic characteristics of the Middle Rio Grande (MRG) in central New Mexico have been of both interest and concern for the regulatory agencies involved with its management. The MRG has experienced sedimentation problems, prompting the development and implementation of sediment detention and flood control features, including the construction of Cochiti Dam in 1973...

Expulsion of Fibroids to the Endometrial Cavity after Magnetic Resonance Imaging-guided High Intensity Focused Ultrasound Surgery (MRgFUS) Treatment of Intramural Uterine Fibroids

PubMed Central

Jeong, Jae-Hyeok; Hong, Gil Pyo; Kim, Yu-Ri; Hong, Da Gyo; Ha, Jae-Eun; Yeom, Jung In; Kim, Eun-Jeong; Kim, Hyung-Il

2016-01-01

Objectives This report seeks to introduce some cases of the patients who received magnetic resonance imaging (MRI)-guided high intensity focused ultrasound (HIFU) surgery (MRgFUS)-based intramural uterine fibroids treatment where the post-MRgFUS intramural uterine fibroids decreased in its volume and protruded towards the endometrial cavity to be expelled by hysteroscopy. Methods Of the 157 patients who had received MRgFUS treatment in the Obstetrics and Gynecology of the Hospital from March, 2015 to February, 2016; this study examined 6 of the cases where, after high intensity focused ultrasound treatment, intramural uterine fibroids protruded towards the endometrial cavity to be removed by hysteroscopic myomectomy. The high intensity focused ultrasound utilized in the cases were Philips Achieva 1.5 Tesla MR (Philips Healthcare, Best, The Netherlands) and Sonalleve HIFU system. Results The volume of fibroids ranged from 26.0 cm3 to 199.5 cm3, averaging 95.6 cm3. The major axis length ranged from 4.0 cm to 8.2 cm, averaging 6.3 cm. Fibroid location in all of the patients was in intramural uterine before treatment but after the high intensity focused ultrasound treatment, the fibroids were observed to protrude towards the endometrial cavity in at least Day 5 or up to Day 73 to allow hysteroscopic myomectomy. Conclusions In some cases, after an intramural uterine fibroid is treated with MRgFUS, fibroid volume is decreased and the fibroid protrudes towards the endometrial cavity. In this case, hysteroscopic myomectomy can be a useful solution. PMID:28119893

Impact of non-native plant removal on lizards in riparian habitats in the southwestern United States

Treesearch

Heather L. Bateman; Alice Chung-MacCoubrey; Howard L. Snell

2008-01-01

Many natural processes in the riparian cottonwood (Populus deltoides) forest of the Middle Rio Grande (MRG) in the southwestern United States have been disrupted or altered, allowing non-native plants such as saltcedar (Tamarix spp.) and Russian olive (Elaeagnus angustifolia) to establish. We investigated...

Robotically assisted MRgFUS system

NASA Astrophysics Data System (ADS)

Jenne, Jürgen W.; Krafft, Axel J.; Maier, Florian; Rauschenberg, Jaane; Semmler, Wolfhard; Huber, Peter E.; Bock, Michael

2010-03-01

Magnetic resonance imaging guided focus ultrasound surgery (MRgFUS) is a highly precise method to ablate tissue non-invasively. The objective of this ongoing work is to establish an MRgFUS therapy unit consisting of a specially designed FUS applicator as an add-on to a commercial robotic assistance system originally designed for percutaneous needle interventions in whole-body MRI systems. The fully MR compatible robotic assistance system InnoMotion™ (Synthes Inc., West Chester, USA; formerly InnoMedic GmbH, Herxheim, Germany) offers six degrees of freedom. The developed add-on FUS treatment applicator features a fixed focus ultrasound transducer (f = 1.7 MHz; f' = 68 mm, NA = 0.44, elliptical shaped -6-dB-focus: 8.1 mm length; O/ = 1.1 mm) embedded in a water-filled flexible bellow. A Mylar® foil is used as acoustic window encompassed by a dedicated MRI loop coil. For FUS application, the therapy unit is directly connected to the head of the robotic system, and the treatment region is targeted from above. A newly in-house developed software tool allowed for complete remote control of the MRgFUS-robot system and online analysis of MRI thermometry data. The system's ability for therapeutic relevant focal spot scanning was tested in a closed-bore clinical 1.5 T MR scanner (Magnetom Symphony, Siemens AG, Erlangen, Germany) in animal experiments with pigs. The FUS therapy procedure was performed entirely under MRI guidance including initial therapy planning, online MR-thermometry, and final contrast enhanced imaging for lesion detection. In vivo trials proved the MRgFUS-robot system as highly MR compatible. MR-guided focal spot scanning experiments were performed and a well-defined pattern of thermal tissue lesions was created. A total in vivo positioning accuracy of the US focus better than 2 mm was estimated which is comparable to existing MRgFUS systems. The newly developed FUS-robotic system offers an accurate, highly flexible focus positioning. With its access to the patient from above, it provides a wide range of flexibility for acoustic target access. In the next step, motion correction unit should be integrated.

Open-source, small-animal magnetic resonance-guided focused ultrasound system.

PubMed

Poorman, Megan E; Chaplin, Vandiver L; Wilkens, Ken; Dockery, Mary D; Giorgio, Todd D; Grissom, William A; Caskey, Charles F

2016-01-01

MR-guided focused ultrasound or high-intensity focused ultrasound (MRgFUS/MRgHIFU) is a non-invasive therapeutic modality with many potential applications in areas such as cancer therapy, drug delivery, and blood-brain barrier opening. However, the large financial costs involved in developing preclinical MRgFUS systems represent a barrier to research groups interested in developing new techniques and applications. We aim to mitigate these challenges by detailing a validated, open-source preclinical MRgFUS system capable of delivering thermal and mechanical FUS in a quantifiable and repeatable manner under real-time MRI guidance. A hardware and software package was developed that includes closed-loop feedback controlled thermometry code and CAD drawings for a therapy table designed for a preclinical MRI scanner. For thermal treatments, the modular software uses a proportional integral derivative controller to maintain a precise focal temperature rise in the target given input from MR phase images obtained concurrently. The software computes the required voltage output and transmits it to a FUS transducer that is embedded in the delivery table within the magnet bore. The delivery table holds the FUS transducer, a small animal and its monitoring equipment, and a transmit/receive RF coil. The transducer is coupled to the animal via a water bath and is translatable in two dimensions from outside the magnet. The transducer is driven by a waveform generator and amplifier controlled by real-time software in Matlab. MR acoustic radiation force imaging is also implemented to confirm the position of the focus for mechanical and thermal treatments. The system was validated in tissue-mimicking phantoms and in vivo during murine tumor hyperthermia treatments. Sonications were successfully controlled over a range of temperatures and thermal doses for up to 20 min with minimal temperature overshoot. MR thermometry was validated with an optical temperature probe, and focus visualization was achieved with acoustic radiation force imaging. We developed an MRgFUS platform for small-animal treatments that robustly delivers accurate, precise, and controllable sonications over extended time periods. This system is an open source and could increase the availability of low-cost small-animal systems to interdisciplinary researchers seeking to develop new MRgFUS applications and technology.

A study of novel bilateral thermal capsulotomy with focused ultrasound for treatment-refractory obsessive-compulsive disorder: 2-year follow-up.

PubMed

Kim, Se Joo; Roh, Daeyoung; Jung, Hyun Ho; Chang, Won Seok; Kim, Chan-Hyung; Chang, Jin Woo

2018-05-02

Recently, a new thermal lesioning approach using magnetic-resonance-guided focused ultrasound (MRgFUS) was introduced for the treatment of neurologic disorders. However, only 2 studies have used this approach for treatment-refractory obsessive-compulsive disorder (OCD), and follow-up was short-term. We investigated the efficacy and safety of bilateral thermal lesioning of the anterior limb of the internal capsule using MRgFUS in patients with treatment-refractory OCD and followed them for 2 years. Eleven patients with treatment-refractory OCD were included in the study. Clinical outcomes were evaluated using the Yale-Brown Obsessive Compulsive Scale, the Clinical Global Impression scale (including improvement and severity), the Hamilton Rating Scale for Depression (HAM-D) and the Hamilton Rating Scale for Anxiety (HAM-A) at 1 week and 1, 3, 6, 12 and 24 months following MRgFUS. Neuropsychological functioning, Global Assessment of Functioning and adverse events were also assessed. After MRgFUS, Yale-Brown Obsessive Compulsive Scale scores decreased significantly across the 24-month follow-up period (mean ± standard deviation, 34.4 ± 2.3 at baseline v. 21.3 ± 6.2 at 24 months, p < 0.001). Scores on the Hamilton rating scales for depression and anxiety also significantly decreased from baseline to 24 months (HAM-D, 19.0 ± 5.3 v. 7.6 ± 5.3, p < 0.001; HAM-A, 22.4 ± 5.9 v. 7.9 ± 3.9, p < 0.001). Global Assessment of Functioning scores improved significantly (35.8 ± 4.9 at baseline v. 56.0 ± 10.3 at 24 months, p < 0.001) and Memory Quotient significantly improved, but other neuropsychological functions were unchanged. The side effects of MRgFUS included headache and vestibular symptoms, but these were mild and transient. The main limitations of this study were the small sample size and the open-label design. Bilateral thermal lesioning of the anterior limb of the internal capsule using MRgFUS may improve obsessive-compulsive, depressive and anxiety symptoms in patients with treatment-refractory OCD, without serious adverse effects.

Multidisciplinary analysis of invasive meningococcal disease as a framework for continuous quality and safety improvement in regional Australia

PubMed Central

Taylor, Kathryn A; Durrheim, David N; Merritt, Tony; Massey, Peter; Ferguson, John; Ryan, Nick; Hullick, Carolyn

2018-01-01

Background System factors in a regional Australian health district contributed to avoidable care deviations from invasive meningococcal disease (IMD) management guidelines. Traditional root cause analysis (RCA) is not well-suited to IMD, focusing on individual cases rather than system improvements. As IMD requires complex care across healthcare silos, it presents an opportunity to explore and address system-based patient safety issues. Context Baseline assessment of IMD cases (2005–2006) identified inadequate triage, lack of senior clinician review, inconsistent vital sign recording and laboratory delays as common issues, resulting in antibiotic administration delays and inappropriate or premature discharge. Methods Clinical governance, in partnership with clinical and public health services, established a multidisciplinary Meningococcal Reference Group (MRG) to routinely review management of all IMD cases. The MRG comprised representatives from primary care, acute care, public health, laboratory medicine and clinical governance. Baseline data were compared with two subsequent evaluation points (2011–2012 and 2013–2015). Interventions Phase I involved multidisciplinary process mapping and development of a standardised audit tool from national IMD management guidelines. Phase II involved formalisation of group processes and advocacy for operational change. Phase III focused on dissemination of findings to clinicians and managers. Results Greatest care improvements were observed in the final evaluation. Median antibiotic delay decreased from 72 to 42 min and proportion of cases triaged appropriately improved from 38% to 75% between 2013 and 2015. Increasing fatal outcomes were attributed to the emergence of more virulent meningococcal serotypes. Conclusions The MRG was a key mechanism for identifying system gaps, advocating for change and enhancing communication and coordination across services. Employing IMD case review as a focus for district-level process reflection presents an innovative patient safety approach, combining the strengths of prospective hazard analysis with more traditional RCA methodologies. PMID:29527576

Cost-effectiveness of uterine-preserving procedures for the treatment of uterine fibroid symptoms in the USA.

PubMed

Cain-Nielsen, Anne H; Moriarty, James P; Stewart, Elizabeth A; Borah, Bijan J

2014-09-01

To evaluate the cost-effectiveness of the following three treatments of uterine fibroids in a population of premenopausal women who wish to preserve their uteri: myomectomy, magnetic resonance-guided focused ultrasound (MRgFUS) and uterine artery embolization (UAE). A decision analytic Markov model was constructed. Cost-effectiveness was calculated in terms of US$ per quality-adjusted life year (QALY) over 5 years. Two types of costs were calculated: direct costs only, and the sum of direct and indirect (productivity) costs. Women in the hypothetical cohort were assessed for treatment type eligibility, were treated based on eligibility, and experienced adequate or inadequate symptom relief. Additional treatment (myomectomy) occurred for inadequate symptom relief or recurrence. Sensitivity analysis was conducted to evaluate uncertainty in the model parameters.  In the base case, myomectomy, MRgFUS and UAE had the following combinations of mean cost and mean QALYs, respectively: US$15,459, 3.957; US$15,274, 3.953; and US$18,653, 3.943. When incorporating productivity costs, MRgFUS incurred a mean cost of US$21,232; myomectomy US$22,599; and UAE US$22,819. Using probabilistic sensitivity analysis (PSA) and excluding productivity costs, myomectomy was cost effective at almost every decision threshold. Using PSA and incorporating productivity costs, myomectomy was cost effective at decision thresholds above US$105,000/QALY; MRgFUS was cost effective between US$30,000 and US$105,000/QALY; and UAE was cost effective below US$30,000/QALY. Myomectomy, MRgFUS, and UAE were similarly effective in terms of QALYs gained. Depending on assumptions about costs and willingness to pay for additional QALYs, all three treatments can be deemed cost effective in a 5-year time frame.

Cost comparison between uterine-sparing fibroid treatments one year following treatment

PubMed Central

2014-01-01

Background To compare one-year all-cause and uterine fibroid (UF)-related direct costs in patients treated with one of the following three uterine-sparing procedures: magnetic resonance-guided focused ultrasound (MRgFUS), uterine artery embolization (UAE) and myomectomy. Methods This retrospective observational cohort study used healthcare claims for several million individuals with healthcare coverage from employers in the MarketScan Database for the period 2003–2010. UF patients aged 25–54 on their first UF procedure (index) date with 366-day baseline experience, 366-day follow-up period, continuous health plan enrollment during baseline and follow-up, and absence of any baseline UF procedures were included in the final sample. Cost outcomes were measured by allowed charges (sum of insurer-paid and patient-paid amounts). UF-related cost was defined as difference in mean cost between study cohorts and propensity-score-matched control cohorts without UF. Multivariate adjustment of cost outcomes was conducted using generalized linear models. Results The study sample comprised 14,426 patients (MRgFUS = 14; UAE = 4,092; myomectomy = 10,320) with a higher percent of older patients in MRgFUS cohort (71% vs. 50% vs. 12% in age-group 45–54, P < 0.001). Adjusted all-cause mean cost was lowest for MRgFUS ($19,763; 95% CI: $10,425-$38,694) followed by myomectomy ($20,407; 95% CI: $19,483-$21,381) and UAE ($25,019; 95% CI: $23,738-$26,376) but without statistical significance. Adjusted UF-related costs were also not significantly different between the three procedures. Conclusions Adjusted all-cause and UF-related costs at one year were not significantly different between patients undergoing MRgFUS, myomectomy and UAE. PMID:25512868

MR-guided transcranial focused ultrasound safely enhances interstitial dispersion of large polymeric nanoparticles in the living brain

PubMed Central

Mohammadabadi, Ali; Nguyen, Ben A.; Guo, Sijia; Winkles, Jeffrey A.; Kim, Anthony J.; Gullapalli, Rao; Keller, Asaf; Frenkel, Victor

2018-01-01

Generating spatially controlled, non-destructive changes in the interstitial spaces of the brain has a host of potential clinical applications, including enhancing the delivery of therapeutics, modulating biological features within the tissue microenvironment, altering fluid and pressure dynamics, and increasing the clearance of toxins, such as plaques found in Alzheimer’s disease. Recently we demonstrated that ultrasound can non-destructively enlarge the interstitial spaces of the brain ex vivo. The goal of the current study was to determine whether these effects could be reproduced in the living brain using non-invasive, transcranial MRI-guided focused ultrasound (MRgFUS). The left striatum of healthy rats was treated using MRgFUS. Computer simulations facilitated treatment planning, and targeting was validated using MRI acoustic radiation force impulse imaging. Following MRgFUS treatments, Evans blue dye or nanoparticle probes were infused to assess changes in the interstitial space. In MRgFUS-treated animals, enhanced dispersion was observed compared to controls for 70 nm (12.8 ± 0.9 mm3 vs. 10.6 ± 1.0 mm3, p = 0.01), 200 nm (10.9 ± 1.4 mm3 vs. 7.4 ± 0.7 mm3, p = 0.01) and 700 nm (7.5 ± 0.4 mm3 vs. 5.4 ± 1.2 mm3, p = 0.02) nanoparticles, indicating enlargement of the interstitial spaces. No evidence of significant histological or electrophysiological injury was identified. These findings suggest that transcranial ultrasound can safely and effectively modulate the brain interstitium and increase the dispersion of large therapeutic entities such as particulate drug carriers or modified viruses. This has the potential to expand the therapeutic uses of MRgFUS. PMID:29415084

Magnetic resonance guided focused ultrasound surgery (MRgFUS) of bone metastases: From primary pain palliation to local tumor control

NASA Astrophysics Data System (ADS)

Napoli, A.; Leonardi, A.; Andrani, F.; Boni, F.; Anzidei, M.; Catalano, C.

2017-03-01

Purpose: To evaluate the clinical performance of MRgFUS in primary pain palliation of painful bone metastases and in local tumor control. Materials and Methods: We enrolled 26 consecutive patients (female/male 12/14; age: 64.7±7.5yrs) with painful bone metastases. Before and 3 months after MRgFUS treatment pain severity and pain interference scores were assessed according to Brief Pain Inventory-Quality of Life (BPI-QoL) criteria and patients underwent both CT and MRI. Local tumor control was evaluated according to lesion size, density and perfusion at CT, dynamic contrast enhancement at MRI (Discovery 750HD, GE; Gd-Bopta, Bracco) and metabolic activity at PET or scintigraphy. Patients were classified as responders or non-responders. Results: No treatment-related adverse events were recorded during the study. As statistically significant difference between baseline and follow-up values for both pain severity and pain interference scores was observed (p<0.05). Increased bone density was observed in 9/26 (34.6%) patients. Non-Perfused Volume values ranged between 20% and 92%. There was no difference in NPV values between responders and non-responders (46.7±24.2% [25 - 90 %] vs. 45±24.9% [20 - 93 %]; p=0.7). In 6 patients (5 prostate and 1 breast primary cancer) there was nearly absence of metabolic activity after treatment (mean SUV=1.2). Conclusion: MRgFUS can be safely and effectively used as the primary treatment for pain palliation in patients with painful bone metastases; moreover our experience demonstrated also a potential role for the MRgFUS in local tumor control.

Detection of macrolide resistance genes in culture-negative specimens from Bangladeshi children with invasive pneumococcal diseases.

PubMed

Hasanuzzaman, Md; Malaker, Roly; Islam, Maksuda; Baqui, Abdullah H; Darmstadt, Gary L; Whitney, Cynthia G; Saha, Samir K

2017-03-01

In recent years, an increasing prevalence of macrolide resistance among pneumococci in Bangladesh has been observed. However, the scenario remains incomplete, as few isolates (<1%) are available from pneumonia cases and most pneumococcal meningitis cases (>80%) are culture-negative. This study optimised a triplex PCR method to detect macrolide resistance genes (MRGs) (mefA and ermB) and cpsA from culture-negative pneumococcal cases to predict the prevalence and level of macrolide resistance. The presence of MRGs among pneumococcal strains (n=153) with a wide range of erythromycin MICs (<0.5 to ≥256mg/L) was determined by PCR. Triplex PCR was validated by simultaneous detection of MRG(s) and cpsA in culture-negative clinical specimens and corresponding isolates. The known impact of the presence of specific MRG(s) on MICs of strains was used to predict the MICs of non-culturable strains based on the presence/absence of MRG(s) in the specimens. None of the erythromycin-susceptible isolates possessed any of the MRGs, and all non-susceptible strains had ≥1 MRG. MICs were 2-16mg/L and ≥256mg/L for 93% of strains with mefA and ermB, respectively, whereas 100% of isolates with both genes had MICs≥256mg/L. PCR for body fluids showed 100% concordance with corresponding isolates when tested for MRG(s) in parallel. Erythromycin MICs can be predicted for non-culturable strains with 93-100% precision based on detection of ermB and/or mefA. This method will be useful for establishing comprehensive surveillance for macrolide resistance among pneumococci, specifically in the population with prior antibiotic use. Copyright © 2017. Published by Elsevier Ltd.

MRI predictors of clinical success in MR-guided focused ultrasound (MRgFUS) treatments of uterine fibroids: results from a single centre.

PubMed

Mindjuk, Irene; Trumm, Christoph G; Herzog, Peter; Stahl, Robert; Matzko, Matthias

2015-05-01

To assess the technical and clinical results of MRgFUS treatment and factors affecting clinical treatment success. A total of 252 women (mean age, 42.1 ± 6.9 years) with uterine fibroids underwent MRgFUS. All patients underwent MRI before treatment. Results were evaluated with respect to post-treatment nonperfused volume (NPV), symptom severity score (SSS), reintervention rate, pregnancy and safety data. NPV ratio was significantly higher in fibroids characterized by low signal intensity in contrast-enhanced T1-weighted fat saturated MR images and in fibroids distant from the spine (>3 cm). NPV ratio was lower in fibroids with septations, with subserosal component and in skin-distant fibroids (p < 0.001). NPV ratio was highly correlated with clinical success: NPV of more than 80 % resulted in clinical success in more than 80 % of patients. Reintervention rate was 12.7 % (mean follow-up time, 19.4 ± 8 months; range, 3-38). Expulsion of fibroids (21 %) was significantly correlated with a high clinical success rate. No severe adverse events were reported. Adequate patient selection and correct treatment techniques, based on the learning curve of this technology, combined with technical advances of the system, lead to higher clinical success rates with low complications rate, comparable to other uterine-sparing treatment options. • MRgFUS appears to be a valid alternative to other uterus-preserving therapies • Patient selection is a significant factor in achieving high NPV ratios • MRI screening parameters correlate with the amount of fibroid ablation in MRgFUS • NPV results of more than 80 % correlate with higher clinical success rates.

Magnetic resonance guided high-intensity focused ultrasound ablation of musculoskeletal tumors

PubMed Central

Avedian, Raffi S.; Gold, Garry; Ghanouni, Pejman; Pauly, Kim Butts

2015-01-01

This article reviews the fundamental principles and clinical experimental uses of magnetic resonance guided high-intensity focused ultrasound (MRgHIFU) ablation of musculoskeletal tumors. MRgHIFU is a noninvasive treatment modality that takes advantage of the ability of magnetic resonance to measure tissue temperature and uses this technology to guide high-intensity focused ultrasound waves to a specific focus within the human body that results in heat generation and complete thermal necrosis of the targeted tissue. Adjacent normal tissues are spared because of the accurate delivery of thermal energy, as well as, local blood perfusion that provides a cooling effect. MRgHIFU is approved by the Food and Drug Administration for the treatment of uterine fibroids and is used on an experimental basis to treat breast, prostate, liver, bone, and brain tumors. PMID:26120376

High intensity focused ultrasound surgery (HIFU) of the brain: A historical perspective, with modern applications

PubMed Central

Jagannathan, Jay; Sanghvi, Narendra K; Crum, Lawrence A; Yen, Chun-Po; Medel, Ricky; Dumont, Aaron S; Sheehan, Jason P; Steiner, Ladislau; Jolesz, Ferenc; Kassell, Neal F

2014-01-01

The field of MRI-guided high intensity focused ultrasound surgery (MRgFUS) is a rapidly evolving one with many potential applications in neurosurgery. This is the first of three articles on MRgFUS, this paper focuses on the historical development of the technology and it's potential applications to modern neurosurgery. The evolution of MRgFUS has occurred in parallel with modern neurological surgery and the two seemingly distinct disciplines share many of the same pioneering figures. Early studies on focused ultrasound treatment in the 1940's and 1950's demonstrated the ability to perform precise lesioning in the human brain, with a favorable risk-benefit profile. However, the need for a craniotomy, as well as lack of sophisticated imaging technology resulted in limited growth of HIFU for neurosurgery. More recently, technological advances, have permitted the combination of HIFU along with MRI guidance to provide an opportunity to effectively treat a variety of CNS disorders. Although challenges remain, HIFU-mediated neurosurgery may offer the ability to target and treat CNS conditions that were previously extremely difficult to perform. The remaining two articles in this series will focus on the physical principles of modern MRgFUS as well as current and future avenues for investigation. PMID:19190451

Evaluation of mineral oil as an acoustic coupling medium in clinical MRgFUS.

PubMed

Gorny, K R; Hangiandreou, N J; Hesley, G K; Felmlee, J P

2007-01-07

We empirically evaluate mineral oil as an alternative to the mixture of de-gassed water and ultrasound gel, which is currently used as an acoustic coupling medium in clinical magnetic resonance guided focused ultrasound (MRgFUS) treatments. The tests were performed on an ExAblate 2000 MRgFUS system (InSightec Inc., Haifa, Israel) using a clinical patient set-up. Acoustic reflections, treatment temperatures, sonication spot dimensions and position with respect to target location were measured, using both coupling media, in repeated sonications in a tissue mimicking gel phantom. In comparison with the water-gel mix, strengths of acoustic reflections from coupling layers prepared with mineral oil were on average 39% lower and the difference was found to be statistically significant (p = 3.3 x 10(-8)). The treatment temperatures were found to be statistically equivalent for both coupling media, although temperatures corresponding to mineral oil tended to be somewhat higher (on average 1.9 degrees C) and their standard deviations were reduced by about 1 degrees C. Measurements of sonication spot dimensions and positions with respect to target location did not reveal systematic differences. We conclude that mineral oil may be used as an effective non-evaporating acoustic coupling medium for clinical MRgFUS treatments.

ExAblate magnetic resonance-guided focused ultrasound system in multiple body applications.

PubMed

Dick, E A; Gedroyc, W M W

2010-09-01

Focused ultrasound surgery (FUS) is a completely noninvasive method of thermally destroying a target tissue while sparing adjacent tissues and organs. Treatment is relatively painless and can be carried out under conscious sedation on an out-patient basis. The combination of magnetic resonance guidance with FUS (MRgFUS) provides the ability to plan and monitor treatments in near real-time, further increasing the safety profile of MRgFUS. This technology provides a very personalized treatment, adjusted to the individual patient anatomy, pathology and treatment response, hence it meets the needs of patients, as well as of physicians. MRgFUS has been used extensively in the successful treatment of uterine fibroids, and has been shown to be an effective treatment in the breast and in bone metastases in smaller scale studies. It shows great potential in the treatment of prostate and liver tumors, as well as in the brain and facet joints.

Exploring the link between MORF4L1 and risk of breast cancer.

PubMed

Martrat, Griselda; Maxwell, Christopher M; Tominaga, Emiko; Porta-de-la-Riva, Montserrat; Bonifaci, Núria; Gómez-Baldó, Laia; Bogliolo, Massimo; Lázaro, Conxi; Blanco, Ignacio; Brunet, Joan; Aguilar, Helena; Fernández-Rodríguez, Juana; Seal, Sheila; Renwick, Anthony; Rahman, Nazneen; Kühl, Julia; Neveling, Kornelia; Schindler, Detlev; Ramírez, María J; Castellà, María; Hernández, Gonzalo; Easton, Douglas F; Peock, Susan; Cook, Margaret; Oliver, Clare T; Frost, Debra; Platte, Radka; Evans, D Gareth; Lalloo, Fiona; Eeles, Rosalind; Izatt, Louise; Chu, Carol; Davidson, Rosemarie; Ong, Kai-Ren; Cook, Jackie; Douglas, Fiona; Hodgson, Shirley; Brewer, Carole; Morrison, Patrick J; Porteous, Mary; Peterlongo, Paolo; Manoukian, Siranoush; Peissel, Bernard; Zaffaroni, Daniela; Roversi, Gaia; Barile, Monica; Viel, Alessandra; Pasini, Barbara; Ottini, Laura; Putignano, Anna Laura; Savarese, Antonella; Bernard, Loris; Radice, Paolo; Healey, Sue; Spurdle, Amanda; Chen, Xiaoqing; Beesley, Jonathan; Rookus, Matti A; Verhoef, Senno; Tilanus-Linthorst, Madeleine A; Vreeswijk, Maaike P; Asperen, Christi J; Bodmer, Danielle; Ausems, Margreet G E M; van Os, Theo A; Blok, Marinus J; Meijers-Heijboer, Hanne E J; Hogervorst, Frans B L; Goldgar, David E; Buys, Saundra; John, Esther M; Miron, Alexander; Southey, Melissa; Daly, Mary B; Harbst, Katja; Borg, Ake; Rantala, Johanna; Barbany-Bustinza, Gisela; Ehrencrona, Hans; Stenmark-Askmalm, Marie; Kaufman, Bella; Laitman, Yael; Milgrom, Roni; Friedman, Eitan; Domchek, Susan M; Nathanson, Katherine L; Rebbeck, Timothy R; Johannsson, Oskar Thor; Couch, Fergus J; Wang, Xianshu; Fredericksen, Zachary; Cuadras, Daniel; Moreno, Víctor; Pientka, Friederike K; Depping, Reinhard; Caldés, Trinidad; Osorio, Ana; Benítez, Javier; Bueren, Juan; Heikkinen, Tuomas; Nevanlinna, Heli; Hamann, Ute; Torres, Diana; Caligo, Maria Adelaide; Godwin, Andrew K; Imyanitov, Evgeny N; Janavicius, Ramunas; Sinilnikova, Olga M; Stoppa-Lyonnet, Dominique; Mazoyer, Sylvie; Verny-Pierre, Carole; Castera, Laurent; de Pauw, Antoine; Bignon, Yves-Jean; Uhrhammer, Nancy; Peyrat, Jean-Philippe; Vennin, Philippe; Ferrer, Sandra Fert; Collonge-Rame, Marie-Agnès; Mortemousque, Isabelle; McGuffog, Lesley; Chenevix-Trench, Georgia; Pereira-Smith, Olivia M; Antoniou, Antonis C; Cerón, Julián; Tominaga, Kaoru; Surrallés, Jordi; Pujana, Miguel Angel

2011-04-05

Proteins encoded by Fanconi anemia (FA) and/or breast cancer (BrCa) susceptibility genes cooperate in a common DNA damage repair signaling pathway. To gain deeper insight into this pathway and its influence on cancer risk, we searched for novel components through protein physical interaction screens. Protein physical interactions were screened using the yeast two-hybrid system. Co-affinity purifications and endogenous co-immunoprecipitation assays were performed to corroborate interactions. Biochemical and functional assays in human, mouse and Caenorhabditis elegans models were carried out to characterize pathway components. Thirteen FANCD2-monoubiquitinylation-positive FA cell lines excluded for genetic defects in the downstream pathway components and 300 familial BrCa patients negative for BRCA1/2 mutations were analyzed for genetic mutations. Common genetic variants were genotyped in 9,573 BRCA1/2 mutation carriers for associations with BrCa risk. A previously identified co-purifying protein with PALB2 was identified, MRG15 (MORF4L1 gene). Results in human, mouse and C. elegans models delineate molecular and functional relationships with BRCA2, PALB2, RAD51 and RPA1 that suggest a role for MRG15 in the repair of DNA double-strand breaks. Mrg15-deficient murine embryonic fibroblasts showed moderate sensitivity to γ-irradiation relative to controls and reduced formation of Rad51 nuclear foci. Examination of mutants of MRG15 and BRCA2 C. elegans orthologs revealed phenocopy by accumulation of RPA-1 (human RPA1) nuclear foci and aberrant chromosomal compactions in meiotic cells. However, no alterations or mutations were identified for MRG15/MORF4L1 in unclassified FA patients and BrCa familial cases. Finally, no significant associations between common MORF4L1 variants and BrCa risk for BRCA1 or BRCA2 mutation carriers were identified: rs7164529, Ptrend = 0.45 and 0.05, P2df = 0.51 and 0.14, respectively; and rs10519219, Ptrend = 0.92 and 0.72, P2df = 0.76 and 0.07, respectively. While the present study expands on the role of MRG15 in the control of genomic stability, weak associations cannot be ruled out for potential low-penetrance variants at MORF4L1 and BrCa risk among BRCA2 mutation carriers.

Exploring the link between MORF4L1 and risk of breast cancer

PubMed Central

2011-01-01

Introduction Proteins encoded by Fanconi anemia (FA) and/or breast cancer (BrCa) susceptibility genes cooperate in a common DNA damage repair signaling pathway. To gain deeper insight into this pathway and its influence on cancer risk, we searched for novel components through protein physical interaction screens. Methods Protein physical interactions were screened using the yeast two-hybrid system. Co-affinity purifications and endogenous co-immunoprecipitation assays were performed to corroborate interactions. Biochemical and functional assays in human, mouse and Caenorhabditis elegans models were carried out to characterize pathway components. Thirteen FANCD2-monoubiquitinylation-positive FA cell lines excluded for genetic defects in the downstream pathway components and 300 familial BrCa patients negative for BRCA1/2 mutations were analyzed for genetic mutations. Common genetic variants were genotyped in 9,573 BRCA1/2 mutation carriers for associations with BrCa risk. Results A previously identified co-purifying protein with PALB2 was identified, MRG15 (MORF4L1 gene). Results in human, mouse and C. elegans models delineate molecular and functional relationships with BRCA2, PALB2, RAD51 and RPA1 that suggest a role for MRG15 in the repair of DNA double-strand breaks. Mrg15-deficient murine embryonic fibroblasts showed moderate sensitivity to γ-irradiation relative to controls and reduced formation of Rad51 nuclear foci. Examination of mutants of MRG15 and BRCA2 C. elegans orthologs revealed phenocopy by accumulation of RPA-1 (human RPA1) nuclear foci and aberrant chromosomal compactions in meiotic cells. However, no alterations or mutations were identified for MRG15/MORF4L1 in unclassified FA patients and BrCa familial cases. Finally, no significant associations between common MORF4L1 variants and BrCa risk for BRCA1 or BRCA2 mutation carriers were identified: rs7164529, Ptrend = 0.45 and 0.05, P2df = 0.51 and 0.14, respectively; and rs10519219, Ptrend = 0.92 and 0.72, P2df = 0.76 and 0.07, respectively. Conclusions While the present study expands on the role of MRG15 in the control of genomic stability, weak associations cannot be ruled out for potential low-penetrance variants at MORF4L1 and BrCa risk among BRCA2 mutation carriers. PMID:21466675

Safe and stable noninvasive focal gene delivery to the mammalian brain following focused ultrasound.

PubMed

Stavarache, Mihaela A; Petersen, Nicholas; Jurgens, Eric M; Milstein, Elizabeth R; Rosenfeld, Zachary B; Ballon, Douglas J; Kaplitt, Michael G

2018-04-27

OBJECTIVE Surgical infusion of gene therapy vectors has provided opportunities for biological manipulation of specific brain circuits in both animal models and human patients. Transient focal opening of the blood-brain barrier (BBB) by MR-guided focused ultrasound (MRgFUS) raises the possibility of noninvasive CNS gene therapy to target precise brain regions. However, variable efficiency and short follow-up of studies to date, along with recent suggestions of the potential for immune reactions following MRgFUS BBB disruption, all raise questions regarding the viability of this approach for clinical translation. The objective of the current study was to evaluate the efficiency, safety, and long-term stability of MRgFUS-mediated noninvasive gene therapy in the mammalian brain. METHODS Focused ultrasound under the control of MRI, in combination with microbubbles consisting of albumin-coated gas microspheres, was applied to rat striatum, followed by intravenous infusion of an adeno-associated virus serotype 1/2 (AAV1/2) vector expressing green fluorescent protein (GFP) as a marker. Following recovery, animals were followed from several hours up to 15 months. Immunostaining for GFP quantified transduction efficiency and stability of expression. Quantification of neuronal markers was used to determine histological safety over time, while inflammatory markers were examined for evidence of immune responses. RESULTS Transitory disruption of the BBB by MRgFUS resulted in efficient delivery of the AAV1/2 vector to the targeted rodent striatum, with 50%-75% of striatal neurons transduced on average. GFP transgene expression appeared to be stable over extended periods of time, from 2 weeks to 6 months, with evidence of ongoing stable expression as long as 16 months in a smaller cohort of animals. No evidence of substantial toxicity, tissue injury, or neuronal loss was observed. While transient inflammation from BBB disruption alone was noted for the first few days, consistent with prior observations, no evidence of brain inflammation was observed from 2 weeks to 6 months following MRgFUS BBB opening, despite delivery of a virus and expression of a foreign protein in target neurons. CONCLUSIONS This study demonstrates that transitory BBB disruption using MRgFUS can be a safe and efficient method for site-specific delivery of viral vectors to the brain, raising the potential for noninvasive focal human gene therapy for neurological disorders.

Habitat use of the Rio Grande silvery minnow (Hybognathus amarus) during a long-term flood pulse in the Middle Rio Grande, New Mexico

Treesearch

Hugo A. Magana

2012-01-01

The Middle Rio Grande (MRG) of New Mexico has been influenced by man for over 500 years. Native Americans began diverting water to irrigate agricultural crops in the floodplain in the 14th century. The Spanish followed and increased agricultural irrigation to over 125 000 acres. Frequent flooding of the MRG valley in the 19th century led to many engineering projects in...

MRI-guided focused ultrasound thalamotomy in non-ET tremor syndromes.

PubMed

Fasano, Alfonso; Llinas, Maheleth; Munhoz, Renato P; Hlasny, Eugen; Kucharczyk, Walter; Lozano, Andres M

2017-08-22

To report the 6-month single-blinded results of unilateral thalamotomy with MRI-guided focused ultrasound (MRgFUS) in patients with tremors other than essential tremor. Three patients with tremor due to Parkinson disease, 2 with dystonic tremor in the context of cervicobrachial dystonia and writer's cramp, and 1 with dystonia gene-associated tremor underwent MRgFUS targeting the ventro-intermedius nucleus (Vim) of the dominant hemisphere. The primary endpoint was the reduction of lateralized items of the Tremor Rating Scale of contralateral hemibody assessed by a blinded rater. All patients achieved a statistically significant, immediate, and sustained improvement of the contralateral tremor score by 42.2%, 52.0%, 55.9%, and 52.9% at 1 week and 1, 3, and 6 months after the procedure, respectively. All patients experienced transient side effects and 2 patients experienced persistent side effects at the time of last evaluation: hemitongue numbness and hemiparesis with hemihypoesthesia. Vim MRgFUS is a promising, incision-free, but nevertheless invasive technique to effectively treat tremors other than essential tremor. Future studies on larger samples and longer follow-up will further define its effectiveness and safety. NCT02252380. This study provides Class IV evidence that for patients with tremor not caused by essential tremor, MRgFUS of the Vim improves the tremor of the contralateral hemibody at 6 months. © 2017 American Academy of Neurology.

Efficacy of Magnetic Resonance-guided Focused Ultrasound Surgery for Bone Metastases Pain Palliation

NASA Astrophysics Data System (ADS)

Kawasaki, Motohiro; Nanba, Hirofumi; Kato, Tomonari; Tani, Toshikazu; Ushida, Takahiro

2011-09-01

Magnetic resonance-guided focused ultrasound surgery (MRgFUS) is a novel treatment method that achieves non-invasive thermal ablation by focusing many ultrasound waves on a target tissue with real-time monitoring of the location and temperature of the target during the procedure. We investigated the palliative effect on pain and safety of MRgFUS in painful bone metastases. Six patients (mean age, 65.8 years) who met eligibility criteria for the clinical study approved by our Institutional Ethics Committee based on the cooperative protocol were treated with MRgFUS. Targeted sites included the sacrum (n = 1), ilium (n = 2), scapula (n = 2), and femur (n = 1). The mean follow-up period was 9.2 months. All procedures were performed as a single-session treatment using the treatment system that is integrated into the patient table of a magnetic resonance image (MRI) scanner. Endpoints were change in the intensity of pain due to bone metastases from before to after the treatment, as measured on a numerical rating scale, pain interference with daily activities as determined by the Brief pain inventory (BPI), change in images, and safety. Pain relief was obtained in all patients early after treatment, with a reduction in the mean pain score from 6.0±1.3 at baseline to 1.2±1.0 at the end of follow-up as well as in pain interference with daily activities. The mean time required for a single-session treatment was 83.7±37.0 min, with a mean number of sonications required of 13.3±3.7 and mean energy applied of 846.4±273.5 J. No significant growth of tumors was observed, nor were there treatment-related adverse events. These results suggest that MRgFUS has a non-invasive palliative effect on the localized pain in patients with bone metastasis. MRgFUS could become an option in treatment strategies for painful bone metastases in the future.

MR-guided focused ultrasound: a potentially disruptive technology.

PubMed

Bradley, William G

2009-07-01

A disruptive technology is a technological innovation that overturns the existing dominant technologies in a market. Magnetic resonance (MR)-guided focused ultrasound (MRgFUS) is a noninvasive procedure based on the combination of real-time MR anatomic guidance, MR thermometry, and high-intensity focused ultrasound. Several hundred transducer elements become convergent at a point under MR guidance, leading to heating and coagulation necrosis. Outside the focal point, there is no significant heating. There is no need to break the skin for procedures in the body or to perform a craniotomy for procedures in the brain. This lack of invasiveness is what makes MRgFUS so disruptive compared with surgery. At present, MRgFUS has been used for the ablation of uterine fibroids, breast tumors, painful bony metastases, and liver tumors. In the brain, it has been used for the ablation of glioblastomas and for functional neurosurgery. Phantom and animal studies suggest future applications for prostate cancer and acute stroke treatment.

First noninvasive thermal ablation of a brain tumor with MR-guided focused ultrasound

PubMed Central

2014-01-01

Magnetic resonance-guided focused ultrasound surgery (MRgFUS) allows for precise thermal ablation of target tissues. While this emerging modality is increasingly used for the treatment of various types of extracranial soft tissue tumors, it has only recently been acknowledged as a modality for noninvasive neurosurgery. MRgFUS has been particularly successful for functional neurosurgery, whereas its clinical application for tumor neurosurgery has been delayed for various technical and procedural reasons. Here, we report the case of a 63-year-old patient presenting with a centrally located recurrent glioblastoma who was included in our ongoing clinical phase I study aimed at evaluating the feasibility and safety of transcranial MRgFUS for brain tumor ablation. Applying 25 high-power sonications under MR imaging guidance, partial tumor ablation could be achieved without provoking neurological deficits or other adverse effects in the patient. This proves, for the first time, the feasibility of using transcranial MR-guided focused ultrasound to safely ablate substantial volumes of brain tumor tissue. PMID:25671132

Usage of Magnetic Resonance Guided Focused Ultrasound Surgery (mrgfus) in Oncology

NASA Astrophysics Data System (ADS)

Bauer, Yair

2011-09-01

Magnetic resonance guided focused ultrasound surgery (MRgFUS) is a non-invasive incision-less surgical approach which limits the tissue destruction to the targeted tumor. Acoustic energy penetrates through intact skin and through the tissues surrounding the tumor without causing any significant bio-effects. Energy deposition takes place mainly at the focal spot where heat induced thermal coagulation of the targeted tissue is accomplished. Real time targeting and image guidance is provided by MRI tumor margin definition and real time thermometry provides closed loop feedback control of energy deposition. The patient lies in the MRI scanner throughout the treatment planning and treatment, and the physician conducts the treatment from the MRgFUS workstation in the adjacent MR control room. The ExAblate system for MRgFUS is commercially available in many countries for treatment of uterine fibroids. The system has also received CE and KFDA approval for pain palliation of bone metastases, and research of other oncologic applications is underway.

Magnetic resonance-guided focused ultrasound surgery (MRgFUS) of uterine fibroids in Singapore.

PubMed

Han, Nian-Lin R; Ong, Chiou Li

2014-11-01

Uterine fibroids are the most common type of gynaecologic benign tumours, occurring in 25% to 50% of women during their reproductive lives. About half of the affected women have clinically significant symptoms, including abnormal bleeding, menstrual pain, frequent urination, constipation and abdominal distension. Magnetic resonance-guided focused ultrasound surgery (MRgFUS) has been used to treat patients with benign lesions and a variety of malignancies. The objective of this study is to evaluate symptom relief before and after MR-guided ultrasound ablation of fibroids. A total of 37 patients with symptomatic uterine fibroids were treated in this study. MRgFUS treatment led to a significant, time-dependent decrease in not only Symptom Severity Scores (SSS), but also the mean fibroid volume. The average reductions in volume were 41.6% and 52.6% at 6 months and 12 months respectively (P <0.05). The mean SSS of the 37 patients was 41.7 ± 2.8 before treatment whereas the average SSS was 26.9 ± 3.6, 20.7 ± 3.4, 18.5 ± 3.6, 16.5 ± 7.1, 9.8 ± 3.6 at 3 months, 6 months, 1 year, 2 years, and 3 to 4 years respectively. The decrease in scores was significant at all time points up to 3 to 4 years (P <0.05 and P <0.001). MRgFUS is a safe and effective non-invasive treatment for patients with symptomatic fibroids.

Patient-reported Outcome Measurements on the Tolerance of Magnetic Resonance Imaging-guided Radiation Therapy

PubMed Central

Tetar, Shyama; Bakker, Roosje; Jeulink, Marloes; Slotman, Ben J.; Oei, Swie; Haasbeek, Cornelis; De Jong, Karel; Senan, Suresh; Lagerwaard, Frank

2018-01-01

Purpose Magnetic resonance imaging-guided radiation therapy (MRgRT) requires patient positioning within the MR bore and prolonged MR imaging during delivery, both of which are new in radiation oncology. Patient tolerance of MRgRT was prospectively evaluated using patient-reported outcome questionnaires (PRO-Q). Methods Our MRgRT procedure involves daily high-resolution MR scanning, limited re-contouring, daily plan re-optimization, quality assurance (QA), and gated delivery. Patients with claustrophobia are excluded. Mean fraction duration was 45 and 60 minutes for stereotactic treatments during free-breathing and breath-hold, respectively. Patient-controlled video-feedback was used for breath-hold delivery. PRO-Qs collected in the first 150 patients treated included questions on MR-related complaints and also evaluated aspects of active participation. Results Almost one-third of patients (29%) scored at least one PRO-Q item on MR-related complaints as ‘moderate’ or ‘very much’, with noise, feeling cold, and paresthesia being the most frequently scored in this way. Considerable anxiety was reported by 5%, but no medication was required for this in any patient. Patient participation in video feedback for breath-hold delivery was appreciated by the majority of patients, all of whom completed the procedure. Only 5% of patients considered treatment duration to be unacceptably long. Conclusion Despite the lengthy MRgRT procedure, outcomes of PRO-Q indicate that it was well-tolerated by patients. PMID:29719739

Historical Sediment Sources and Delivery on the Lower Mississippi River

NASA Astrophysics Data System (ADS)

Dahl, T. A.; Biedenharn, D. S.; Little, C. D.

2015-12-01

The development of the Lower Mississippi River (LMR) and its floodplain for navigation and flood control has been ongoing since the 18th century, with the most concerted efforts occurring as a result of the Flood Control Act (FCA) of 1928 following the Great Flood of 1927. The Mississippi River and Tributaries (MR&T) Project that was spawned from the FCA of 1928 has produced a massive, comprehensive system for flood control and channel stabilization that includes levees, channel improvements, and floodways, as well as tributary reservoirs and other basin improvements. Additionally, the development of the river for safe and dependable navigation has generated a substantial engineering effort involving river training structures, meander cutoffs, and dredging. The historical, and present-day morphology of the LMR reflects an integration of all these engineering interventions (and the process-responses they have triggered in the fluvial system), combined with natural drivers of channel change and evolution, including floods and droughts, hurricanes, neotectonic activity, geologic outcrops, climate change, and relative sea-level rise. In response to the complex requirements in navigation, flood risk reduction, and environmental restoration, all with multiple stakeholders, the U.S. Army Corps of Engineers created the Mississippi River Geomorphology & Potamology (MRG&P) Program. The goals of the MRG&P are to advance the knowledge of the geomorphology of the LMR and to transfer this technology to improve and sustain long-term management of the system. The results presented herein come from several MRG&P studies. The historical river morphology, and particularly the sources and delivery of sediments have changed dramatically over the past two centuries. In this presentation, the changes in sediment sources, and the manner in which this sediment is delivered through the channel system from the early 1800s to present-day is described.

SU-E-J-161: Inverse Problems for Optical Parameters in Laser Induced Thermal Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fahrenholtz, SJ; Stafford, RJ; Fuentes, DT

Purpose: Magnetic resonance-guided laser-induced thermal therapy (MRgLITT) is investigated as a neurosurgical intervention for oncological applications throughout the body by active post market studies. Real-time MR temperature imaging is used to monitor ablative thermal delivery in the clinic. Additionally, brain MRgLITT could improve through effective planning for laser fiber's placement. Mathematical bioheat models have been extensively investigated but require reliable patient specific physical parameter data, e.g. optical parameters. This abstract applies an inverse problem algorithm to characterize optical parameter data obtained from previous MRgLITT interventions. Methods: The implemented inverse problem has three primary components: a parameter-space search algorithm, a physicsmore » model, and training data. First, the parameter-space search algorithm uses a gradient-based quasi-Newton method to optimize the effective optical attenuation coefficient, μ-eff. A parameter reduction reduces the amount of optical parameter-space the algorithm must search. Second, the physics model is a simplified bioheat model for homogeneous tissue where closed-form Green's functions represent the exact solution. Third, the training data was temperature imaging data from 23 MRgLITT oncological brain ablations (980 nm wavelength) from seven different patients. Results: To three significant figures, the descriptive statistics for μ-eff were 1470 m{sup −1} mean, 1360 m{sup −1} median, 369 m{sup −1} standard deviation, 933 m{sup −1} minimum and 2260 m{sup −1} maximum. The standard deviation normalized by the mean was 25.0%. The inverse problem took <30 minutes to optimize all 23 datasets. Conclusion: As expected, the inferred average is biased by underlying physics model. However, the standard deviation normalized by the mean is smaller than literature values and indicates an increased precision in the characterization of the optical parameters needed to plan MRgLITT procedures. This investigation demonstrates the potential for the optimization and validation of more sophisticated bioheat models that incorporate the uncertainty of the data into the predictions, e.g. stochastic finite element methods.« less

Initial evaluation of acoustic reflectors for the preservation of sensitive abdominal skin areas during MRgFUS treatment.

PubMed

Gorny, Krzysztof R; Chen, Shigao; Hangiandreou, Nicholas J; Hesley, Gina K; Woodrum, David A; Brown, Douglas L; Felmlee, Joel P

2009-04-21

During MR-guided focused ultrasound (MRgFUS) treatments of uterine fibroids using ExAblate(R)2000 (InSightec, Haifa, Israel), individual tissue ablations are performed extracorporeally through the patient's abdomen using an annular array FUS transducer embedded within the MR table. Ultrasound intensities in the near field are below therapeutic levels and, under normal conditions, heating of the patient skin is minimal. However, increased absorption of ultrasound energy within sensitive skin areas or areas with differing acoustic properties, such as scars, may lead to skin burns and therefore these areas must be kept outside the near field of the FUS beam. Depending on their location and size the sensitive areas may either obstruct parts of the fibroid from being treated or prevent the entire MRgFUS treatment altogether. The purpose of this work is to evaluate acoustic reflector materials that can be applied to protect skin and the underlying sensitive areas. Reflection coefficients of cork (0.88) and foam (0.91) based materials were evaluated with a hydrophone. An ExAblate 2000 MRgFUS system was used to simulate clinical treatment with discs of reflector materials placed in a near field underneath a gel phantom. MR thermometry was used to monitor temperature elevations as well as the integrity of the focal spot. The phantom measurements showed acoustic shadow zones behind the reflectors with zone depths changing between 7 and 27 mm, for reflector disc diameters increasing from 10 to 30 mm (40 mm diameter discs completely blocked the FUS beam at the depth evaluated). The effects on thermal lesions due to the presence of the reflectors in the FUS beam were found to diminish with decreasing disc diameter and increasing sonication depth. For a 20 mm diameter disc and beyond 50 mm sonication depth, thermal lesions were minimally affected by the presence of the disc. No heating was observed on the skin side of the foam reflectors, as confirmed by measurements performed with adhesive temperature labels. We present these data and discuss possible applications to clinical MRgFUS treatments.

Scaled signal intensity of uterine fibroids based on T2-weighted MR images: a potential objective method to determine the suitability for magnetic resonance-guided focused ultrasound surgery of uterine fibroids.

PubMed

Park, Hyun; Yoon, Sang-Wook; Sokolov, Amit

2015-12-01

Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) is a non-invasive method to treat uterine fibroids. To help determine the patient suitability for MRgFUS, we propose a new objective measure: the scaled signal intensity (SSI) of uterine fibroids in T2 weighted MR images (T2WI). Forty three uterine fibroids in 40 premenopausal women were included in this retrospective study. SSI of each fibroid was measured from the screening T2WI by standardizing its mean signal intensity to a 0-100 scale, using reference intensities of rectus abdominis muscle (0) and subcutaneous fat (100). Correlation between the SSI and the non-perfused volume (NPV) ratio (a measure for treatment success) was calculated. Pre-treatment SSI showed a significant inverse-correlation with post treatment NPV ratio (p < 0.05). When dichotomizing NPV ratio at 45 %, the optimal cut off value of the SSI was found to be 16.0. A fibroid with SSI value 16.0 or less can be expected to have optimal responses. The SSI of uterine fibroids in T2WI can be suggested as an objective parameter to help in patient selection for MRgFUS. • Signal intensity of fibroid in MR images predicts treatment response to MRgFUS. • Signal intensity is standardized into scaled form using adjacent tissues as references. • Fibroids with SSI less than 16.0 are expected to have optimal responses.

Generalized Polynomial Chaos Based Uncertainty Quantification for Planning MRgLITT Procedures

PubMed Central

Fahrenholtz, S.; Stafford, R. J.; Maier, F.; Hazle, J. D.; Fuentes, D.

2014-01-01

Purpose A generalized polynomial chaos (gPC) method is used to incorporate constitutive parameter uncertainties within the Pennes representation of bioheat transfer phenomena. The stochastic temperature predictions of the mathematical model are critically evaluated against MR thermometry data for planning MR-guided Laser Induced Thermal Therapies (MRgLITT). Methods Pennes bioheat transfer model coupled with a diffusion theory approximation of laser tissue interaction was implemented as the underlying deterministic kernel. A probabilistic sensitivity study was used to identify parameters that provide the most variance in temperature output. Confidence intervals of the temperature predictions are compared to MR temperature imaging (MRTI) obtained during phantom and in vivo canine (n=4) MRgLITT experiments. The gPC predictions were quantitatively compared to MRTI data using probabilistic linear and temporal profiles as well as 2-D 60 °C isotherms. Results Within the range of physically meaningful constitutive values relevant to the ablative temperature regime of MRgLITT, the sensitivity study indicated that the optical parameters, particularly the anisotropy factor, created the most variance in the stochastic model's output temperature prediction. Further, within the statistical sense considered, a nonlinear model of the temperature and damage dependent perfusion, absorption, and scattering is captured within the confidence intervals of the linear gPC method. Multivariate stochastic model predictions using parameters with the dominant sensitivities show good agreement with experimental MRTI data. Conclusions Given parameter uncertainties and mathematical modeling approximations of the Pennes bioheat model, the statistical framework demonstrates conservative estimates of the therapeutic heating and has potential for use as a computational prediction tool for thermal therapy planning. PMID:23692295

Factors associated with successful magnetic resonance-guided focused ultrasound treatment: efficiency of acoustic energy delivery through the skull.

PubMed

Chang, Won Seok; Jung, Hyun Ho; Zadicario, Eyal; Rachmilevitch, Itay; Tlusty, Tal; Vitek, Shuki; Chang, Jin Woo

2016-02-01

Magnetic resonance-guided focused ultrasound surgery (MRgFUS) was recently introduced as treatment for movement disorders such as essential tremor and advanced Parkinson's disease (PD). Although deep brain target lesions are successfully generated in most patients, the target area temperature fails to increase in some cases. The skull is one of the greatest barriers to ultrasonic energy transmission. The authors analyzed the skull-related factors that may have prevented an increase in target area temperatures in patients who underwent MRgFUS. The authors retrospectively reviewed data from clinical trials that involved MRgFUS for essential tremor, idiopathic PD, and obsessive-compulsive disorder. Data from 25 patients were included. The relationships between the maximal temperature during treatment and other factors, including sex, age, skull area of the sonication field, number of elements used, skull volume of the sonication field, and skull density ratio (SDR), were determined. Among the various factors, skull volume and SDR exhibited relationships with the maximum temperature. Skull volume was negatively correlated with maximal temperature (p = 0.023, r(2) = 0.206, y = 64.156 - 0.028x, whereas SDR was positively correlated with maximal temperature (p = 0.009, r(2) = 0.263, y = 49.643 + 11.832x). The other factors correlate with the maximal temperature, although some factors showed a tendency to correlate. Some skull-related factors correlated with the maximal target area temperature. Although the number of patients in the present study was relatively small, the results offer information that could guide the selection of MRgFUS candidates.

Analytical estimation of ultrasound properties, thermal diffusivity, and perfusion using magnetic resonance-guided focused ultrasound temperature data

PubMed Central

Dillon, C R; Borasi, G; Payne, A

2016-01-01

For thermal modeling to play a significant role in treatment planning, monitoring, and control of magnetic resonance-guided focused ultrasound (MRgFUS) thermal therapies, accurate knowledge of ultrasound and thermal properties is essential. This study develops a new analytical solution for the temperature change observed in MRgFUS which can be used with experimental MR temperature data to provide estimates of the ultrasound initial heating rate, Gaussian beam variance, tissue thermal diffusivity, and Pennes perfusion parameter. Simulations demonstrate that this technique provides accurate and robust property estimates that are independent of the beam size, thermal diffusivity, and perfusion levels in the presence of realistic MR noise. The technique is also demonstrated in vivo using MRgFUS heating data in rabbit back muscle. Errors in property estimates are kept less than 5% by applying a third order Taylor series approximation of the perfusion term and ensuring the ratio of the fitting time (the duration of experimental data utilized for optimization) to the perfusion time constant remains less than one. PMID:26741344

Hair sparing does not compromise real-time magnetic resonance imaging guided stereotactic laser fiber placement for temporal lobe epilepsy.

PubMed

Singh, Shikha; Kumar, Kevin K; Rabon, Matthew J; Dolce, Dana; Halpern, Casey H

2018-06-01

Pre-operative scalp shaving is conventionally thought to simplify postoperative cranial wound care, lower the rate of wound infections, and ease optimal incision localization. Over the past few decades, some neurosurgeons have refrained from scalp shaving in order to improve patient satisfaction with brain surgery. However, this hair-sparing approach has not yet been explored in the growing field of magnetic resonance-guided laser interstitial thermal therapy (MRgLITT). This study investigated the initial impact of a no-shave technique on post-operative wound infection rate as well as on entry and target accuracy in MRgLITT for mesial temporal epilepsy. Eighteen patients selected by the Stanford Comprehensive Epilepsy Program between November 2015 and August 2017 were included in the study. All patients underwent functional selective amygdalohippocampotomies using MRgLITT entirely within a diagnostic MRI suite. No hair was removed and no additional precautions were taken for hair or scalp care. Otherwise, routine protocols for surgical preparations and wound closure were followed. The study was performed under approval from Stanford University's Internal Review Board (IRB-37830). No post-operative wound infections or erosions occurred for any patient. The mean entry point error was 2.87 ± 1.3 mm and the mean target error was 1.0 ± 0.9 mm. There have been no other complications associated with this hair-sparing approach. The study's results suggest that hair sparing in MRgLITT surgery for temporal epilepsy does not increase the risk of wound complications or compromise accuracy. This preferred cosmetic approach may thus appeal to epilepsy patients considering such interventions. Copyright © 2018 Elsevier Ltd. All rights reserved.

MRI-guided high-intensity focused ultrasound ablation of bone: evaluation of acute findings with MR and CT imaging in a swine model.

PubMed

Bucknor, Matthew D; Rieke, Viola; Do, Loi; Majumdar, Sharmila; Link, Thomas M; Saeed, Maythem

2014-11-01

To evaluate hyperacute (<1 hour) changes on magnetic resonance (MR) and computed tomography (CT) imaging following MR-guided high-intensity focused ultrasound (MRgHIFU) in a swine bone model as a function of sonication number and energy. Experimental procedures received approval from the local Institutional Animal Care and Use Committee. MRgHIFU was used to create distal and proximal ablations in the right femur of eight pigs. Each target was dosed with four or six sonications within similar volumes. The energy dosed to the distal target was higher (419 ± 19 J) than the proximal target (324 ± 17 J). The targeted femur and contralateral control were imaged before and after ablation using MR at 3T. Qualitative changes in signal on T1-weighted, T2-weighted, and T1-weighted postcontrast images were assessed. Ablation dimensions were calculated from postcontrast MRI. The 64-slice CT images were also obtained before and after ablation and qualitative changes were assessed. MRgHIFU bone ablation size measured on average 8.5 × 21.1 × 16.2 mm (transverse × craniocaudal × anteroposterior). Interestingly, within similar prescribed volumes, increasing the number of sonications from 4 to 6 increased the depth of the intramedullary hypoenhanced zone from 2.9 mm to 6.5 mm (P < 0.001). There was no difference in the appearance of low versus high energy ablations. CT imaging did not show structural abnormalities. The number of MRgHIFU focal sonications can be used to increase the depth of treatment within the targeted bone. Unlike CT, T2-weighted and contrast-enhanced MR demonstrated the hyperacute structural changes in the femur and surrounding soft tissue. © 2013 Wiley Periodicals, Inc.

Improved operative efficiency using a real-time MRI-guided stereotactic platform for laser amygdalohippocampotomy.

PubMed

Ho, Allen L; Sussman, Eric S; Pendharkar, Arjun V; Le, Scheherazade; Mantovani, Alessandra; Keebaugh, Alaine C; Drover, David R; Grant, Gerald A; Wintermark, Max; Halpern, Casey H

2018-04-01

OBJECTIVE MR-guided laser interstitial thermal therapy (MRgLITT) is a minimally invasive method for thermal destruction of benign or malignant tissue that has been used for selective amygdalohippocampal ablation for the treatment of temporal lobe epilepsy. The authors report their initial experience adopting a real-time MRI-guided stereotactic platform that allows for completion of the entire procedure in the MRI suite. METHODS Between October 2014 and May 2016, 17 patients with mesial temporal sclerosis were selected by a multidisciplinary epilepsy board to undergo a selective amygdalohippocampal ablation for temporal lobe epilepsy using MRgLITT. The first 9 patients underwent standard laser ablation in 2 phases (operating room [OR] and MRI suite), whereas the next 8 patients underwent laser ablation entirely in the MRI suite with the ClearPoint platform. A checklist specific to the real-time MRI-guided laser amydalohippocampal ablation was developed and used for each case. For both cohorts, clinical and operative information, including average case times and accuracy data, was collected and analyzed. RESULTS There was a learning curve associated with using this real-time MRI-guided system. However, operative times decreased in a linear fashion, as did total anesthesia time. In fact, the total mean patient procedure time was less in the MRI cohort (362.8 ± 86.6 minutes) than in the OR cohort (456.9 ± 80.7 minutes). The mean anesthesia time was significantly shorter in the MRI cohort (327.2 ± 79.9 minutes) than in the OR cohort (435.8 ± 78.4 minutes, p = 0.02). CONCLUSIONS The real-time MRI platform for MRgLITT can be adopted in an expedient manner. Completion of MRgLITT entirely in the MRI suite may lead to significant advantages in procedural times.

Random number generators tested on quantum Monte Carlo simulations.

PubMed

Hongo, Kenta; Maezono, Ryo; Miura, Kenichi

2010-08-01

We have tested and compared several (pseudo) random number generators (RNGs) applied to a practical application, ground state energy calculations of molecules using variational and diffusion Monte Carlo metheds. A new multiple recursive generator with 8th-order recursion (MRG8) and the Mersenne twister generator (MT19937) are tested and compared with the RANLUX generator with five luxury levels (RANLUX-[0-4]). Both MRG8 and MT19937 are proven to give the same total energy as that evaluated with RANLUX-4 (highest luxury level) within the statistical error bars with less computational cost to generate the sequence. We also tested the notorious implementation of linear congruential generator (LCG), RANDU, for comparison. (c) 2010 Wiley Periodicals, Inc.

Magnetic Resonance Imaging-Guided Focused Ultrasound Surgery for the Treatment of Symptomatic Uterine Fibroids.

PubMed

Geraci, Laura; Napoli, Alessandro; Catalano, Carlo; Midiri, Massimo; Gagliardo, Cesare

2017-01-01

Uterine fibroids, the most common benign tumor in women of childbearing age, may cause symptoms including pelvic pain, menorrhagia, dysmenorrhea, pressure, urinary symptoms, and infertility. Various approaches are available to treat symptomatic uterine fibroids. Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) represents a recently introduced noninvasive safe and effective technique that can be performed without general anesthesia, in an outpatient setting. We review the principles of MRgFUS, describing patient selection criteria for the treatments performed at our center and we present a series of five selected patients with symptomatic uterine fibroids treated with this not yet widely known technique, showing its efficacy in symptom improvement and fibroid volume reduction.

Subcellular compartmentalization of Cd and Zn in two bivalves. I. Significance of metal-sensitive fractions (MSF) and biologically detoxified metal (BDM)

USGS Publications Warehouse

Wallace, W.G.; Lee, B.-G.; Luoma, S.N.

2003-01-01

Many aspects of metal accumulation in aquatic invertebrates (i.e. toxicity, tolerance and trophic transfer) can be understood by examining the subcellular partitioning of accumulated metal. In this paper, we use a compartmentalization approach to interpret the significance of metal, species and size dependence in the subcellular partitioning of Cd and Zn in the bivalves Macoma balthica and Potamocorbula amurensis. Of special interest is the compartmentalization of metal as metal-sensitive fractions (MSF) (i.e. organelles and heat-sensitive proteins, termed 'enzymes' hereafter) and biologically detoxified metal (BDM) (i.e. metallothioneins [MT] and metal-rich granules [MRG]). Clams from San Francisco Bay, CA, were exposed for 14 d to seawater (20??? salinity) containing 3.5 ??g l-1 Cd and 20.5 ??g l-1 Zn, including 109Cd and 65Zn as radiotracers. Uptake was followed by 21 d of depuration. The subcellular partitioning of metal within clams was examined following exposure and loss. P. amurensis accumulated ???22x more Cd and ???2x more Zn than M. balthica. MT played an important role in the storage of Cd in P. amurensis, while organelles were the major site of Zn accumulation. In M. balthica, Cd and Zn partitioned similarly, although the pathway of detoxification was metal-specific (MRG for Cd; MRG and MT for Zn). Upon loss, M. balthica depurated ???40% of Cd with Zn being retained; P. amurensis retained Cd and depurated Zn (???40%). During efflux, Cd and Zn concentrations in the MSF compartment of both clams declined with metal either being lost from the animal or being transferred to the BDM compartment. Subcellular compartmentalization was also size-dependent, with the importance of BDM increasing with clam size; MSF decreased accordingly. We hypothesized that progressive retention of metal as BDM (i.e. MRG) with age may lead to size dependency of metal concentrations often observed in some populations of M. balthica.

[Magnetic resonance guided focused ultrasound surgery for pain palliation of bone metastases: early experience of clinical application in China].

PubMed

Gu, Jianjun; Wang, Han; Tang, Na; Hua, Yingqi; Yang, Haiyan; Qiu, Yimin; Ge, Renbin; Zhou, Ying; Wang, Wenwen; Zhang, Guixiang

2015-11-03

To evaluate the safety and efficacy of magnetic resonance guided focused ultrasound surgery (MRgFUS) in treatment for pain palliation of bone metastases. Eighty-one patients of painful bone metastases were volunteered to screen for this study in Shanghai General Hospital from June 2014 to February 2015. Twenty-three patients among them were treated by MRgFUS, who was more than 18-years old, having the ability to fully understand the informed consent of the research, suffering with pain of numeric rating scale (NRS) ≥ 4, non-received radiotherapy or chemotherapy for pain palliation of bone metastases in the past two weeks. The NRS, the standard question of Brief Pain Inventory (BPI-QoL), and the standard question of Europe Organization for Research and Treatment of Cancer Quality of Life Questionnaire- Bone Metastases 22 (EORTC QLQ-BM22) were respectively recorded before and 1-week, 1-month, 3-month after the treatment. The related adverse events of MRgFUS were observed and recorded in 3 months after the treatment as well. (1)Twenty-three metastatic bone tumor lesions of 23 patients were treated by MRgFUS, the treatment data was as follows: the mean treatment time was (88 ± 33) minutes, the mean sonication number was 13 ± 8. (2) Adverse events included: pain in therapy area 3/23, which spontaneous relieving within one week; numbness in lower limb (1/23), which relieved after physiotherapy. (3) The NRS of before treatment and at 1-week, 1-month, and 3-month after treatment respectively was 6.0 ± 1.5, 3.7 ± 1.7,3.1 ± 2.0, and 2.2 ± 1.0,which significantly decreased after the treatment (P<0.01). (4) The BPI-QoL score of before treatment and at 1-week, 1-month, and 3-month after treatment respectively was 39 ± 16, 27 ± 18, 26 ± 18, and 21 ± 18, which significantly decreased after the treatment (P<0.01). (5) The EORTC QLQ-BM22 score of before treatment and at 1-week, 1-month, and 3-month after treatment respectively was 52 ± 13, 44 ± 12, 42 ± 12, and 39 ± 12, which also significantly decreased after the treatment (P<0.01). MRgFUS can be used as a non-invasive, safe, and effective method for treating painful bone metastases. Its clinical benefits of pain palliation and patient's quality of life improving are sustained after the treatment at least to 3 months.

Ultrashort echo-time MRI versus CT for skull aberration correction in MR-guided transcranial focused ultrasound: In vitro comparison on human calvaria.

PubMed

Miller, G Wilson; Eames, Matthew; Snell, John; Aubry, Jean-François

2015-05-01

Transcranial magnetic resonance-guided focused ultrasound (TcMRgFUS) brain treatment systems compensate for skull-induced beam aberrations by adjusting the phase and amplitude of individual ultrasound transducer elements. These corrections are currently calculated based on a preacquired computed tomography (CT) scan of the patient's head. The purpose of the work presented here is to demonstrate the feasibility of using ultrashort echo-time magnetic resonance imaging (UTE MRI) instead of CT to calculate and apply aberration corrections on a clinical TcMRgFUS system. Phantom experiments were performed in three ex-vivo human skulls filled with tissue-mimicking hydrogel. Each skull phantom was imaged with both CT and UTE MRI. The MR images were then segmented into "skull" and "not-skull" pixels using a computationally efficient, threshold-based algorithm, and the resulting 3D binary skull map was converted into a series of 2D virtual CT images. Each skull was mounted in the head transducer of a clinical TcMRgFUS system (ExAblate Neuro, Insightec, Israel), and transcranial sonications were performed using a power setting of approximately 750 acoustic watts at several different target locations within the electronic steering range of the transducer. Each target location was sonicated three times: once using aberration corrections calculated from the actual CT scan, once using corrections calculated from the MRI-derived virtual CT scan, and once without applying any aberration correction. MR thermometry was performed in conjunction with each 10-s sonication, and the highest single-pixel temperature rise and surrounding-pixel mean were recorded for each sonication. The measured temperature rises were ∼ 45% larger for aberration-corrected sonications than for noncorrected sonications. This improvement was highly significant (p < 10(-4)). The difference between the single-pixel peak temperature rise and the surrounding-pixel mean, which reflects the sharpness of the thermal focus, was also significantly larger for aberration-corrected sonications. There was no significant difference between the sonication results achieved using CT-based and MR-based aberration correction. The authors have demonstrated that transcranial focal heating can be significantly improved in vitro by using UTE MRI to compute skull-induced ultrasound aberration corrections. Their results suggest that UTE MRI could be used instead of CT to implement such corrections on current 0.7 MHz clinical TcMRgFUS devices. The MR image acquisition and segmentation procedure demonstrated here would add less than 15 min to a clinical MRgFUS treatment session.

MRI-guided focused ultrasound surgery in musculoskeletal diseases: the hot topics

PubMed Central

Napoli, Alessandro; Sacconi, Beatrice; Battista, Giuseppe; Guglielmi, Giuseppe; Catalano, Carlo; Albisinni, Ugo

2016-01-01

MRI-guided focused ultrasound surgery (MRgFUS) is a minimally invasive treatment guided by the most sophisticated imaging tool available in today's clinical practice. Both the imaging and therapeutic sides of the equipment are based on non-ionizing energy. This technique is a very promising option as potential treatment for several pathologies, including musculoskeletal (MSK) disorders. Apart from clinical applications, MRgFUS technology is the result of long, heavy and cumulative efforts exploring the effects of ultrasound on biological tissues and function, the generation of focused ultrasound and treatment monitoring by MRI. The aim of this article is to give an updated overview on a “new” interventional technique and on its applications for MSK and allied sciences. PMID:26607640

Ultrasound ablation enhances drug accumulation and survival in mammary carcinoma models.

PubMed

Wong, Andrew W; Fite, Brett Z; Liu, Yu; Kheirolomoom, Azadeh; Seo, Jai W; Watson, Katherine D; Mahakian, Lisa M; Tam, Sarah M; Zhang, Hua; Foiret, Josquin; Borowsky, Alexander D; Ferrara, Katherine W

2016-01-01

Magnetic resonance-guided focused ultrasound (MRgFUS) facilitates noninvasive image-guided conformal thermal therapy of cancer. Yet in many scenarios, the sensitive tissues surrounding the tumor constrain the margins of ablation; therefore, augmentation of MRgFUS with chemotherapy may be required to destroy remaining tumor. Here, we used 64Cu-PET-CT, MRI, autoradiography, and fluorescence imaging to track the kinetics of long-circulating liposomes in immunocompetent mammary carcinoma-bearing FVB/n and BALB/c mice. We observed a 5-fold and 50-fold enhancement of liposome and drug concentration, respectively, within MRgFUS thermal ablation-treated tumors along with dense accumulation within the surrounding tissue rim. Ultrasound-enhanced drug accumulation was rapid and durable and greatly increased total tumor drug exposure over time. In addition, we found that the small molecule gadoteridol accumulates around and within ablated tissue. We further demonstrated that dilated vasculature, loss of vascular integrity resulting in extravasation of blood cells, stromal inflammation, and loss of cell-cell adhesion and tissue architecture all contribute to the enhanced accumulation of the liposomes and small molecule probe. The locally enhanced liposome accumulation was preserved even after a multiweek protocol of doxorubicin-loaded liposomes and partial ablation. Finally, by supplementing ablation with concurrent liposomal drug therapy, a complete and durable response was obtained using protocols for which a sub-mm rim of tumor remained after ablation.

Ultrasound ablation enhances drug accumulation and survival in mammary carcinoma models

PubMed Central

Wong, Andrew W.; Fite, Brett Z.; Liu, Yu; Kheirolomoom, Azadeh; Seo, Jai W.; Watson, Katherine D.; Mahakian, Lisa M.; Tam, Sarah M.; Zhang, Hua; Foiret, Josquin; Borowsky, Alexander D.; Ferrara, Katherine W.

2015-01-01

Magnetic resonance–guided focused ultrasound (MRgFUS) facilitates noninvasive image-guided conformal thermal therapy of cancer. Yet in many scenarios, the sensitive tissues surrounding the tumor constrain the margins of ablation; therefore, augmentation of MRgFUS with chemotherapy may be required to destroy remaining tumor. Here, we used 64Cu-PET-CT, MRI, autoradiography, and fluorescence imaging to track the kinetics of long-circulating liposomes in immunocompetent mammary carcinoma–bearing FVB/n and BALB/c mice. We observed a 5-fold and 50-fold enhancement of liposome and drug concentration, respectively, within MRgFUS thermal ablation–treated tumors along with dense accumulation within the surrounding tissue rim. Ultrasound-enhanced drug accumulation was rapid and durable and greatly increased total tumor drug exposure over time. In addition, we found that the small molecule gadoteridol accumulates around and within ablated tissue. We further demonstrated that dilated vasculature, loss of vascular integrity resulting in extravasation of blood cells, stromal inflammation, and loss of cell-cell adhesion and tissue architecture all contribute to the enhanced accumulation of the liposomes and small molecule probe. The locally enhanced liposome accumulation was preserved even after a multiweek protocol of doxorubicin-loaded liposomes and partial ablation. Finally, by supplementing ablation with concurrent liposomal drug therapy, a complete and durable response was obtained using protocols for which a sub-mm rim of tumor remained after ablation. PMID:26595815

Genome-Wide Association Mapping of Crown Rust Resistance in Oat Elite Germplasm.

PubMed

Klos, Kathy Esvelt; Yimer, Belayneh A; Babiker, Ebrahiem M; Beattie, Aaron D; Bonman, J Michael; Carson, Martin L; Chong, James; Harrison, Stephen A; Ibrahim, Amir M H; Kolb, Frederic L; McCartney, Curt A; McMullen, Michael; Fetch, Jennifer Mitchell; Mohammadi, Mohsen; Murphy, J Paul; Tinker, Nicholas A

2017-07-01

Oat crown rust, caused by f. sp. , is a major constraint to oat ( L.) production in many parts of the world. In this first comprehensive multienvironment genome-wide association map of oat crown rust, we used 2972 single-nucleotide polymorphisms (SNPs) genotyped on 631 oat lines for association mapping of quantitative trait loci (QTL). Seedling reaction to crown rust in these lines was assessed as infection type (IT) with each of 10 crown rust isolates. Adult plant reaction was assessed in the field in a total of 10 location-years as percentage severity (SV) and as infection reaction (IR) in a 0-to-1 scale. Overall, 29 SNPs on 12 linkage groups were predictive of crown rust reaction in at least one experiment at a genome-wide level of statistical significance. The QTL identified here include those in regions previously shown to be linked with seedling resistance genes , , , , , and and also with adult-plant resistance and adaptation-related QTL. In addition, QTL on linkage groups Mrg03, Mrg08, and Mrg23 were identified in regions not previously associated with crown rust resistance. Evaluation of marker genotypes in a set of crown rust differential lines supported as the identity of . The SNPs with rare alleles associated with lower disease scores may be suitable for use in marker-assisted selection of oat lines for crown rust resistance. Copyright © 2017 Crop Science Society of America.

[MR-guided focused ultrasound. Current and future applications].

PubMed

Trumm, C G; Napoli, A; Peller, M; Clevert, D-A; Stahl, R; Reiser, M; Matzko, M

2013-03-01

High-intensity focused ultrasound (synonyms FUS and HIFU) under magnetic resonance imaging (MRI) guidance (synonyms MRgFUS and MR-HIFU) is a completely non-invasive technology for accurate thermal ablation of a target tissue while neighboring tissues and organs are preserved. The combination of FUS with MRI for planning, (near) real-time monitoring and outcome assessment of treatment markedly enhances the safety of the procedure. The MRgFUS procedure is clinically established in particular for the treatment of symptomatic uterine fibroids, followed by palliative ablation of painful bone metastases. Furthermore, promising results have been shown for the treatment of adenomyosis, malignant tumors of the prostate, breast and liver and for various intracranial applications, such as thermal ablation of brain tumors, functional neurosurgery and transient disruption of the blood-brain barrier.

Enhanced Delivery of Gold Nanoparticles with Therapeutic Potential for Targeting Human Brain Tumors

NASA Astrophysics Data System (ADS)

Etame, Arnold B.

The blood brain barrier (BBB) remains a major challenge to the advancement and application of systemic anti-cancer therapeutics into the central nervous system. The structural and physiological delivery constraints of the BBB significantly limit the effectiveness of conventional chemotherapy, thereby making systemic administration a non-viable option for the vast majority of chemotherapy agents. Furthermore, the lack of specificity of conventional systemic chemotherapy when applied towards malignant brain tumors remains a major shortcoming. Hence novel therapeutic strategies that focus both on targeted and enhanced delivery across the BBB are warranted. In recent years nanoparticles (NPs) have emerged as attractive vehicles for efficient delivery of targeted anti-cancer therapeutics. In particular, gold nanoparticles (AuNPs) have gained prominence in several targeting applications involving systemic cancers. Their enhanced permeation and retention within permissive tumor microvasculature provide a selective advantage for targeting. Malignant brain tumors also exhibit transport-permissive microvasculature secondary to blood brain barrier disruption. Hence AuNPs may have potential relevance for brain tumor targeting. However, the permeation of AuNPs across the BBB has not been well characterized, and hence is a potential limitation for successful application of AuNP-based therapeutics within the central nervous system (CNS). In this dissertation, we designed and characterized AuNPs and assessed the role of polyethylene glycol (PEG) on the physical and biological properties of AuNPs. We established a size-dependent permeation profile with respect to core size as well as PEG length when AuNPs were assessed through a transport-permissive in-vitro BBB. This study was the first of its kind to systematically examine the influence of design on permeation of AuNPs through transport-permissive BBB. Given the significant delivery limitations through the non-transport permissive and intact BBB, we also assessed the role of magnetic resonance imaging (MRI) guided focused ultrasound (MRgFUS) disruption of the BBB in enhancing permeation of AuNPs across the intact BBB and tumor BBB in vivo. MRgFUS is a novel technique that can transiently increase BBB permeability thereby allowing delivery of therapeutics into the CNS. We demonstrated enhanced delivery of AuNPs with therapeutic potential into the CNS via MRgFUS. Our study was the first to establish a definitive role for MRgFUS in delivering AuNPs into the CNS. In summary, this thesis describes results from a series of research projects that have contributed to our understanding of the influence of design features on AuNP permeation through the BBB and also the potential role of MRgFUS in AuNP permeation across the BBB.

Focused Ultrasound Hyperthermia Mediated Drug Delivery Using Thermosensitive Liposomes and Visualized With in vivo Two-Photon Microscopy.

PubMed

Santos, Marc A; Goertz, David E; Hynynen, Kullervo

2017-01-01

The future of nanomedicines in oncology requires leveraging more than just the passive drug accumulation in tumors through the enhanced permeability and retention effect. Promising results combining mild hyperthermia (HT) with lyso-thermosensitive liposomal doxorubicin (LTSL-DOX) has led to improved drug delivery and potent antitumor effects in pre-clinical studies. The ultimate patient benefit from these treatments can only be realized when robust methods of HT can be achieved clinically. One of the most promising methods of non-invasive HT is the use of focused ultrasound (FUS) with MRI thermometry for anatomical targeting and feedback. MRI-guided focused ultrasound (MRgFUS) is limited by respiratory motion and large blood vessel cooling. In order to translate exciting pre-clinical results to the clinic, novel heating approaches capable of overcoming the limitations on clinical MRgFUS+HT must be tested and evaluated on their ability to locally release drug from LTSL-DOX. Methods: In this work, a new system is described to integrate focused ultrasound (FUS) into a two-photon microscopy (2PM) setting to image the release of drug from LTSL-DOX in real-time during FUS+HT in vivo . A candidate scheme for overcoming the limitations of respiratory motion and large blood vessel cooling during MRgFUS+HT involves applying FUS+HT to 42°C in short ~30s bursts. The spatiotemporal drug release pattern from LTSL-DOX as a result is quantified using 2PM and compared against continuous (3.5min and 20min at 42°C) FUS+HT schemes and unheated controls. Results: It was observed for the first time in vivo that these short duration temperature elevations could produce substantial drug release from LTSL-DOX. Ten 30s bursts of FUS+HT was able to achieve almost half of the interstitial drug concentration as 20min of continuous FUS+HT. There was no significant difference between the intravascular area under the concentration-time curve for ten 30s bursts of FUS+HT and 3.5min of continuous FUS+HT. Conclusion: We have successfully combined 2PM with FUS+HT for imaging the release of DOX from LTSL-DOX in vivo in real-time, which will permit the investigation of FUS+HT heating schemes to improve drug delivery from LTSL-DOX. We have evaluated the ability to release DOX in short 30s FUS+HT bursts to 42°C as a method to overcome limitations on clinical MRgFUS+HT and have found that such exposures are capable of releasing measurable amounts of drug. Such an exposure has the potential to overcome limitations that hamper conventional MRgFUS+HT treatments in targets that are associated with substantial tissue motion.

Prospective feasibility analysis of a novel off-line approach for MR-guided radiotherapy.

PubMed

Bostel, Tilman; Pfaffenberger, Asja; Delorme, Stefan; Dreher, Constantin; Echner, Gernot; Haering, Peter; Lang, Clemens; Splinter, Mona; Laun, Frederik; Müller, Marco; Jäkel, Oliver; Debus, Jürgen; Huber, Peter E; Sterzing, Florian; Nicolay, Nils H

2018-05-01

The present work aimed to analyze the feasibility of a shuttle-based MRI-guided radiation therapy (MRgRT) in the treatment of pelvic malignancies. 20 patients with pelvic malignancies were included in this prospective feasibility analysis. Patients underwent daily MRI in treatment position prior to radiotherapy at the German Cancer Research Center. Positional inaccuracies, time and patient compliance were assessed for the application of off-line MRgRT. In 78% of applied radiation fractions, MR imaging for position verification could be performed without problems. Additionally, treatment-related side effects and reduced patient compliance were only responsible for omission of MRI in 9% of radiation fractions. The study workflow took a median time of 61 min (range 47-99 min); duration for radiotherapy alone was 13 min (range 7-26 min). Patient positioning, MR imaging and CT imaging including patient repositioning and the shuttle transfer required median times of 10 min (range 7-14 min), 26 min (range 15-60 min), 5 min (range 3-8 min) and 8 min (range 2-36 min), respectively. To assess feasibility of shuttle-based MRgRT, the reference point coordinates for the x, y and z axis were determined for the MR images and CT obtained prior to the first treatment fraction and correlated with the coordinates of the planning CT. In our dataset, the median positional difference between MR imaging and CT-based imaging based on fiducial matching between MR and CT imaging was equal to or less than 2 mm in all spatial directions. The limited space in the MR scanner influenced patient selection, as the bore of the scanner had to accommodate the immobilization device and the constructed stereotactic frame. Therefore, obese, extremely muscular or very tall patients could not be included in this trial in addition to patients for whom exposure to MRI was generally judged inappropriate. This trial demonstrated for the first time the feasibility and patient compliance of a shuttle-based off-line approach to MRgRT of pelvic malignancies.

Observations of planetary mixed Rossby-gravity waves in the upper stratosphere

NASA Technical Reports Server (NTRS)

Randel, William J.; Boville, Byron A.; Gille, John C.

1990-01-01

Observational evidence is presented for planetary scale (zonal wave number 1-2) mixed Rossby-gravity (MRG) waves in the equatorial upper stratosphere (35-50 km). These waves are detected in LIMS measurements as coherently propagating temperature maxima of amplitude 0.1-0.3 K, which are antisymmetric (out of phase) about the equator, centered near 10-15 deg north and south latitude. These features have vertical wavelengths of order 10-15 km, periods near 2-3 days, and zonal phase velocities close to 200 m/s. Both eastward and westward propagating waves are found, and the observed vertical wavelengths and meridional structures are in good agreement with the MRG dispersion relation. Theoretical estimates of the zonal accelerations attributable to these waves suggest they do not contribute substantially to the zonal momentum balance in the middle atmosphere.

Effects of pelletized anticoagulant rodenticides on California quail

USGS Publications Warehouse

Blus, L.J.; Henny, C.J.; Grove, R.A.

1985-01-01

A moribund, emaciated California quail (Callipepla californica) that was found in an orchard in the state of Washington had an impacted crop and gizzard. Pellets containing the anticoagulant chlorophacinone (Rozol, RO) were in the crop; the gizzard contents consisted of a pink mass of paraffin that was selectively accumulated from the paraffinized pellets. The plasma prothrombin time of 28 sec was near that determined for control quail. The signs of RO intoxication seen in the moribund wild quail were duplicated in captive quail given ad libitum diets of either RO or another paraffinized chlorophacinone pellet (Mr. Rat Guard II, MRG). This left little doubt that paraffin impaction of the gizzard was the primary problem. All captive quail fed RO or MRG pellets showed no increases in prothrombin times compared to control values, died in an emaciated condition, and had gizzards impacted with paraffin.

Custom molded thermal MRg-FUS phantom

NASA Astrophysics Data System (ADS)

Eames, Matthew D. C.; Snell, John W.; Hananel, Arik; Kassell, Neal F.

2012-11-01

This article describes a method for creating custom-molded thermal phantoms for use with MR-guided focused ultrasound systems. The method is defined here for intracranial applications, though it may be modified for other anatomical targets.

MR-guided Focused Ultrasound for Uterine Fibroids

MedlinePlus

... Professions Site Index A-Z MR-guided Focused Ultrasound for Uterine Fibroids Magnetic Resonance-guided Focused Ultrasound ( ... are the limitations of MRgFUS? What is Focused Ultrasound of Uterine Fibroids? Magnetic Resonance-guided Focused Ultrasound ( ...

A long arm for ultrasound: a combined robotic focused ultrasound setup for magnetic resonance-guided focused ultrasound surgery.

PubMed

Krafft, Axel J; Jenne, Jürgen W; Maier, Florian; Stafford, R Jason; Huber, Peter E; Semmler, Wolfhard; Bock, Michael

2010-05-01

Focused ultrasound surgery (FUS) is a highly precise noninvasive procedure to ablate pathogenic tissue. FUS therapy is often combined with magnetic resonance (MR) imaging as MR imaging offers excellent target identification and allows for continuous monitoring of FUS induced temperature changes. As the dimensions of the ultrasound (US) focus are typically much smaller than the targeted volume, multiple sonications and focus repositioning are interleaved to scan the focus over the target volume. Focal scanning can be achieved electronically by using phased-array US transducers or mechanically by using dedicated mechanical actuators. In this study, the authors propose and evaluate the precision of a combined robotic FUS setup to overcome some of the limitations of the existing MRgFUS systems. Such systems are typically integrated into the patient table of the MR scanner and thus only provide an application of the US wave within a limited spatial range from below the patient. The fully MR-compatible robotic assistance system InnoMotion (InnoMedic GmbH, Herxheim, Germany) was originally designed for MR-guided interventions with needles. It offers five pneumatically driven degrees of freedom and can be moved over a wide range within the bore of the magnet. In this work, the robotic system was combined with a fixed-focus US transducer (frequency: 1.7 MHz; focal length: 68 mm, and numerical aperture: 0.44) that was integrated into a dedicated, in-house developed treatment unit for FUS application. A series of MR-guided focal scanning procedures was performed in a polyacrylamide-egg white gel phantom to assess the positioning accuracy of the combined FUS setup. In animal experiments with a 3-month-old domestic pig, the system's potential and suitability for MRgFUS was tested. In phantom experiments, a total targeting precision of about 3 mm was found, which is comparable to that of the existing MRgFUS systems. Focus positioning could be performed within a few seconds. During in vivo experiments, a defined pattern of single thermal lesions and a therapeutically relevant confluent thermal lesion could be created. The creation of local tissue necrosis by coagulation was confirmed by post-FUS MR imaging and histological examinations on the treated tissue sample. During all sonications in phantom and in vivo, reliable MR imaging and online MR thermometry could be performed without compromises due to operation of the combined robotic FUS setup. Compared to the existing MRgFUS systems, the combined robotic FUS approach offers a wide range of spatial flexibility so that highly flexible application of the US wave would be possible, for example, to avoid risk structures within the US field. The setup might help to realize new ways of patient access in MRgFUS therapy. The setup is compatible with any closed-bore MR system and does not require an especially designed patient table.

Acoustic characterization of Thiel liver for magnetic resonance-guided focused ultrasound treatment.

PubMed

Karakitsios, Ioannis; Joy, Joyce; Mihcin, Senay; Melzer, Andreas

2017-04-01

The purpose of this work was to measure the essential acoustic parameters, i.e., acoustic impedance, reflection coefficient, attenuation coefficient, of Thiel embalmed human and animal liver. The Thiel embalmed tissue can be a promising, pre-clinical model to study liver treatment with Magnetic Resonance-guided Focused Ultrasound (MRgFUS). Using a single-element transducer and the contact pulse-echo method, the acoustic parameters, i.e., acoustic impedance, reflection coefficient and attenuation coefficient of Thiel embalmed human and animal liver were measured. The Thiel embalmed livers had higher impedance, similar reflection and lower attenuation compared to the fresh tissue. Embalming liver with Thiel fluid affects its acoustic properties. During MRgFUS sonication of a Thiel organ, more focused ultrasound (FUS) will be backscattered by the organ, and higher acoustic powers are required to reach coagulation levels (temperatures >56 °C).

Clinical Consideration of Treatment to Ablate Uterine Fibroids with Magnetic Resonance Imaging-guided High Intensity Focused Ultrasound (MRgFUS): Sonalleve

PubMed Central

Jeong, Jae-Hyeok; Hong, Gil Pyo; Kim, Yu-Ri; Ha, Jae-Eun

2016-01-01

Objectives Magnetic resonance imaging (MRI)-guided high intensity focused ultrasound surgery (MRgFUS) is a newly emerging non-invasive technique for the treatment of uterine fibroids. The purpose of this study is to review the clinical impact of MRgFUS. Methods This study examined 157 patients. The high intensity focused ultrasound (HIFU) utilized in this study was Philips Achieva 1.5 Tesla MR (Philips Healthcare, Best, the Netherlands) and Sonalleve HIFU system. The patients were followed in post-operative Month 1, Month 3, and Month 6 to investigate any change. Then, these were further classified according to the use of uterine stimulant (oxytocin) in parallel, Funaki Type of uterine fibroid, HIFU intensity, and non-perfused volume (NPV) ratio. Results When the uterine stimulant was utilized, the HIFU intensity was measured at significantly lower levels, compared with the group not using uterine stimulant, and treatment duration was significantly. The NPV ratio was found significantly higher in the group using uterine stimulant. Concerning the correlation between Funaki Type of uterine fibroid and average sonication power, it was found that the closer to Type I, the lower the sonication power, the shorter the treatment duration, and the higher the NPV ratio significantly. Conclusions In this study, it was found that the lower the Funaki Types of uterine fibroids, and the higher the NPV ratio immediately after the operation, the larger the uterine fibroid volume decrease and SSS change were. Also, if uterine stimulant was used in parallel in treatment, treatment duration and HIFU intensity could become shorter and lower. PMID:27617244

Feasibility Study on MR-Guided High-Intensity Focused Ultrasound Ablation of Sciatic Nerve in a Swine Model: Preliminary Results.

PubMed

Kaye, Elena A; Gutta, Narendra Babu; Monette, Sebastien; Gulati, Amitabh; Loh, Jeffrey; Srimathveeravalli, Govindarajan; Ezell, Paula C; Erinjeri, Joseph P; Solomon, Stephen B; Maybody, Majid

2015-08-01

Spastic patients often seek neurolysis, the permanent destruction of the sciatic nerve, for better pain management. MRI-guided high-intensity focused ultrasound (MRgHIFU) may serve as a noninvasive alternative to the prevailing, more intrusive techniques. This in vivo acute study is aimed at performing sciatic nerve neurolysis using a clinical MRgHIFU system. The HIFU ablation of sciatic nerves was performed in swine (n = 5) using a HIFU system integrated with a 3 T MRI scanner. Acute lesions were confirmed using T1-weighted contrast-enhanced (CE) MRI and histopathology using hematoxylin and eosin staining. The animals were euthanized immediately following post-ablation imaging. Reddening and mild thickening of the nerve and pallor of the adjacent muscle were seen in all animals. The HIFU-treated sections of the nerves displayed nuclear pyknosis of Schwann cells, vascular hyperemia, perineural edema, hyalinization of the collagenous stroma of the nerve, myelin sheet swelling, and loss of axons. Ablations were visible on CE MRI. Non-perfused volume of the lesions (5.8-64.6 cc) linearly correlated with estimated lethal thermal dose volume (4.7-34.2 cc). Skin burn adjacent to the largest ablated zone was observed in the first animal. Bilateral treatment time ranged from 55 to 138 min, and preparation time required 2 h on average. The acute pilot study in swine demonstrated the feasibility of a noninvasive neurolysis of the sciatic nerve using a clinical MRgHIFU system. Results revealed that acute HIFU nerve lesions were detectable on CE MRI, gross pathology, and histology.

Development and validation of a MRgHIFU non-invasive tissue acoustic property estimation technique.

PubMed

Johnson, Sara L; Dillon, Christopher; Odéen, Henrik; Parker, Dennis; Christensen, Douglas; Payne, Allison

2016-11-01

MR-guided high-intensity focussed ultrasound (MRgHIFU) non-invasive ablative surgeries have advanced into clinical trials for treating many pathologies and cancers. A remaining challenge of these surgeries is accurately planning and monitoring tissue heating in the face of patient-specific and dynamic acoustic properties of tissues. Currently, non-invasive measurements of acoustic properties have not been implemented in MRgHIFU treatment planning and monitoring procedures. This methods-driven study presents a technique using MR temperature imaging (MRTI) during low-temperature HIFU sonications to non-invasively estimate sample-specific acoustic absorption and speed of sound values in tissue-mimicking phantoms. Using measured thermal properties, specific absorption rate (SAR) patterns are calculated from the MRTI data and compared to simulated SAR patterns iteratively generated via the Hybrid Angular Spectrum (HAS) method. Once the error between the simulated and measured patterns is minimised, the estimated acoustic property values are compared to the true phantom values obtained via an independent technique. The estimated values are then used to simulate temperature profiles in the phantoms, and compared to experimental temperature profiles. This study demonstrates that trends in acoustic absorption and speed of sound can be non-invasively estimated with average errors of 21% and 1%, respectively. Additionally, temperature predictions using the estimated properties on average match within 1.2 °C of the experimental peak temperature rises in the phantoms. The positive results achieved in tissue-mimicking phantoms presented in this study indicate that this technique may be extended to in vivo applications, improving HIFU sonication temperature rise predictions and treatment assessment.

Development of a 3D remote dosimetry protocol compatible with MRgIMRT.

PubMed

Mein, Stewart; Rankine, Leith; Adamovics, John; Li, Harold; Oldham, Mark

2017-11-01

To develop a novel remote 3D dosimetry protocol to verify Magnetic Resonance-guided Radiation Therapy (MRgRT) treatments. The protocol was applied to investigate the accuracy of TG-119 IMRT irradiations delivered by the MRIdian ® system (ViewRay ® , Oakwood Village, OH, USA) allowing for a 48-hour delay between irradiation at a field institution and subsequent readout at a base institution. The 3D dosimetry protocol utilizes a novel formulation of PRESAGE ® radiochromic dosimeters developed for high postirradiation stability and compatibility with optical-CT readout. Optical-CT readout was performed with an in-house system utilizing telecentric lenses affording high-resolution scanning. The protocol was developed from preparatory experiments to characterize PRESAGE ® response in relevant conditions. First, linearity and sensitivity of PRESAGE ® dose-response in the presence of a magnetic field was evaluated in a small volume study (4 ml cuvettes) conducted under MRgRT conditions and irradiated with doses 0-15 Gy. Temporal and spatial stability of the dose-response were investigated in large volume studies utilizing large field-of-view (FOV) 2 kg cylindrical PRESAGE ® dosimeters. Dosimeters were imaged at t = 1 hr and t = 48 hrs enabling the development of correction terms to model any observed spatial and temporal changes postirradiation. Polynomial correction factors for temporal and spatial changes in PRESAGE ® dosimeters (C T and C R respectively) were obtained by numerical fitting to time-point data acquired in six irradiated dosimeters. A remote dosimetry protocol was developed where PRESAGE ® change in optical-density (ΔOD) readings at time t = X (the irradiation to return shipment time interval) were corrected back to a convenient standard time t = 1 hr using the C T and C R corrections. This refined protocol was then applied to TG-119 (American Association of Physicists in Medicine, Task Group 119) plan deliveries on the MRIdian ® system to evaluate the accuracy of MRgRT in these conditions. In the small volume study, in the presence of a 0.35 T magnetic field, PRESAGE ® was observed to respond linearly (R 2  = 0.9996) to Co-60 irradiation at t = 48 hrs postirradiation, within the dose ranges of 0 to 15 Gy, with a sensitivity of 0.0305(±0.003) ΔOD cm -1  Gy -1 . In the large volume studies, at t = 1 hr postirradiation, consistent linear response was observed, with average sensitivity of 0.0930 ± 0.002 ΔOD cm -1  Gy -1 . However, dosimeters gradually darkened with time (OD< 5% per day). A small radial dependence to the dosimeter sensitivity was measured (< 3% of maximum dose), which is attributed to a spherically symmetric dosimeter artifact arising from exothermic heating legacy in the PRESAGE ® polyurethane substrate during curing. When applied to the TG-119 IMRT irradiations, the remote dosimetry protocol (including correction terms) yielded excellent line-profile and 3D gamma agreement for 3%/3 mm, 10% threshold (mean passing rate = 96.6% ± 4.0%). A novel 3D remote dosimetry protocol is introduced for validating off-site dosimetrically complex radiotherapy systems, including MRgRT. The protocol involves correcting for temporal and spatially dependent changes in PRESAGE ® radiochromic dosimeters readout by optical-CT. Application of the protocol to TG-119 irradiations enabled verification of MRgRT dose distributions with high resolution. © 2017 American Association of Physicists in Medicine.

Analysis of Magnetic Resonance Image Signal Fluctuations Acquired During MR-Guided Radiotherapy.

PubMed

Breto, Adrian L; Padgett, Kyle R; Ford, John C; Kwon, Deukwoo; Chang, Channing; Fuss, Martin; Stoyanova, Radka; Mellon, Eric A

2018-03-28

Magnetic resonance-guided radiotherapy (MRgRT) is a new and evolving treatment modality that allows unprecedented visualization of the tumor and surrounding anatomy. MRgRT includes daily 3D magnetic resonance imaging (MRI) for setup and rapidly repeated near real-time MRI scans during treatment for target tracking. One of the more exciting potential benefits of MRgRT is the ability to analyze serial MRIs to monitor treatment response or predict outcomes. A typical radiation treatment (RT) over the span of 10-15 minutes on the MRIdian system (ViewRay, Cleveland, OH) yields thousands of "cine" images, each acquired in 250 ms. This unique data allows for a glimpse in image intensity changes during RT delivery. In this report, we analyze cine images from a single fraction RT of a glioblastoma patient on the ViewRay platform in order to characterize the dynamic signal changes occurring during RT therapy. The individual frames in the cines were saved into DICOM format and read into an MIM image analysis platform (MIM Software, Cleveland, OH) as a time series. The three possible states of the three Cobalt-60 radiation sources-OFF, READY, and ON-were also recorded. An in-house Java plugin for MIM was created in order to perform principal component analysis (PCA) on each of the datasets. The analysis resulted in first PC, related to monotonous signal increase over the course of the treatment fraction. We found several distortion patterns in the data that we postulate result from the perturbation of the magnetic field due to the moving metal parts in the platform while treatment was being administered. The largest variations were detected when all Cobalt-60 sources were OFF. During this phase of the treatment, the gantry and multi-leaf collimators (MLCs) are moving. Conversely, when all Cobalt-60 sources were in the ON position, the image signal fluctuations were minimal, relating to very little mechanical motion. At this phase, the gantry, the MLCs, and sources are fixed in their positions. These findings were confirmed in a study with the daily quality assurance (QA) phantom. While the identified variations were not related to physiological processes, our findings confirm the sensitivity of the developed approach to identify very small fluctuations. Relating these variations to the physical changes that occur during treatment shows the methodical ability of the technique to uncover their underlying sources.

Design and validation of an MR-conditional robot for transcranial focused ultrasound surgery in infants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Price, Karl D., E-mail: karl.price@sickkids.ca

Purpose: Current treatment of intraventricular hemorrhage (IVH) involves cerebral shunt placement or an invasive brain surgery. Magnetic resonance-guided focused ultrasound (MRgFUS) applied to the brains of pediatric patients presents an opportunity to treat IVH in a noninvasive manner, termed “incision-less surgery.” Current clinical and research focused ultrasound systems lack the capability to perform neonatal transcranial surgeries due to either range of motion or dexterity requirements. A novel robotic system is proposed to position a focused ultrasound transducer accurately above the head of a neonatal patient inside an MRI machine to deliver the therapy. Methods: A clinical Philips Sonalleve MRgFUS systemmore » was expanded to perform transcranial treatment. A five degree-of-freedom MR-conditional robot was designed and manufactured using MR compatible materials. The robot electronics and control were integrated into existing Philips electronics and software interfaces. The user commands the position of the robot with a graphical user interface, and is presented with real-time MR imaging of the patient throughout the surgery. The robot is validated through a series of experiments that characterize accuracy, signal-to-noise ratio degeneration of an MR image as a result of the robot, MR imaging artifacts generated by the robot, and the robot’s ability to operate in a representative surgical environment inside an MR machine. Results: Experimental results show the robot responds reliably within an MR environment, has achieved 0.59 ± 0.25 mm accuracy, does not produce severe MR-imaging artifacts, has a workspace providing sufficient coverage of a neonatal brain, and can manipulate a 5 kg payload. A full system demonstration shows these characteristics apply in an application environment. Conclusions: This paper presents a comprehensive look at the process of designing and validating a new robot from concept to implementation for use in an MR environment. An MR conditional robot has been designed and manufactured to design specifications. The system has demonstrated its feasibility as a platform for MRgFUS interventions for neonatal patients. The success of the system in experimental trials suggests that it is ready to be used for validation of the transcranial intervention in animal studies.« less

Feasibility Study on MR-Guided High-Intensity Focused Ultrasound Ablation of Sciatic Nerve in a Swine Model: Preliminary Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaye, Elena A., E-mail: kayee@mskcc.org; Gutta, Narendra Babu, E-mail: gnbabu.aiims@gmail.com; Monette, Sebastien, E-mail: monettes@mskcc.org

IntroductionSpastic patients often seek neurolysis, the permanent destruction of the sciatic nerve, for better pain management. MRI-guided high-intensity focused ultrasound (MRgHIFU) may serve as a noninvasive alternative to the prevailing, more intrusive techniques. This in vivo acute study is aimed at performing sciatic nerve neurolysis using a clinical MRgHIFU system.MethodsThe HIFU ablation of sciatic nerves was performed in swine (n = 5) using a HIFU system integrated with a 3 T MRI scanner. Acute lesions were confirmed using T1-weighted contrast-enhanced (CE) MRI and histopathology using hematoxylin and eosin staining. The animals were euthanized immediately following post-ablation imaging.ResultsReddening and mild thickening of themore » nerve and pallor of the adjacent muscle were seen in all animals. The HIFU-treated sections of the nerves displayed nuclear pyknosis of Schwann cells, vascular hyperemia, perineural edema, hyalinization of the collagenous stroma of the nerve, myelin sheet swelling, and loss of axons. Ablations were visible on CE MRI. Non-perfused volume of the lesions (5.8–64.6 cc) linearly correlated with estimated lethal thermal dose volume (4.7–34.2 cc). Skin burn adjacent to the largest ablated zone was observed in the first animal. Bilateral treatment time ranged from 55 to 138 min, and preparation time required 2 h on average.ConclusionThe acute pilot study in swine demonstrated the feasibility of a noninvasive neurolysis of the sciatic nerve using a clinical MRgHIFU system. Results revealed that acute HIFU nerve lesions were detectable on CE MRI, gross pathology, and histology.« less

Statistical and Conceptual Model Testing Geomorphic Principles through Quantification in the Middle Rio Grande River, NM.

NASA Astrophysics Data System (ADS)

Posner, A. J.

2017-12-01

The Middle Rio Grande River (MRG) traverses New Mexico from Cochiti to Elephant Butte reservoirs. Since the 1100s, cultivating and inhabiting the valley of this alluvial river has required various river training works. The mid-20th century saw a concerted effort to tame the river through channelization, Jetty Jacks, and dam construction. A challenge for river managers is to better understand the interactions between a river training works, dam construction, and the geomorphic adjustments of a desert river driven by spring snowmelt and summer thunderstorms carrying water and large sediment inputs from upstream and ephemeral tributaries. Due to its importance to the region, a vast wealth of data exists for conditions along the MRG. The investigation presented herein builds upon previous efforts by combining hydraulic model results, digitized planforms, and stream gage records in various statistical and conceptual models in order to test our understanding of this complex system. Spatially continuous variables were clipped by a set of river cross section data that is collected at decadal intervals since the early 1960s, creating a spatially homogenous database upon which various statistical testing was implemented. Conceptual models relate forcing variables and response variables to estimate river planform changes. The developed database, represents a unique opportunity to quantify and test geomorphic conceptual models in the unique characteristics of the MRG. The results of this investigation provides a spatially distributed characterization of planform variable changes, permitting managers to predict planform at a much higher resolution than previously available, and a better understanding of the relationship between flow regime and planform changes such as changes to longitudinal slope, sinuosity, and width. Lastly, data analysis and model interpretation led to the development of a new conceptual model for the impact of ephemeral tributaries in alluvial rivers.

In vivo optimisation study for multi-baseline MR-based thermometry in the context of hyperthermia using MR-guided high intensity focused ultrasound for head and neck applications.

PubMed

Pichardo, Samuel; Köhler, Max; Lee, Justin; Hynnyen, Kullervo

2014-12-01

In this in vivo study, the feasibility to perform hyperthermia treatments in the head and neck using magnetic resonance image-guided high intensity focused ultrasound (MRgHIFU) was established using a porcine acute model. Porcine specimens with a weight between 17 and 18 kg were treated in the omohyoid muscle in the neck. Hyperthermia was applied with a target temperature of 41 °C for 30 min using a Sonalleve MRgHIFU system. MR-based thermometry was calculated using water-proton resonance frequency shift and multi-baseline look-up tables indexed by peak-to-peak displacement (Dpp) measurements using a pencil-beam navigator. Three hyperthermia experiments were conducted at different Dpp values of 0.2, 1.0 and 3.0 mm. An optimisation study was carried out to establish the optimal parameters controlling the multi-baseline method that ensured a minimisation of spatial-average peak-to-peak temperature (TSA-pp) and temperature direct current bias (TSA-DC). The multi-baseline technique reduced considerably the noise on both TSA-pp and TSA-DC. The reduction of noise was more important when Dpp was higher. For Dpp = 3 mm the average (±standard deviation (SD)) of TSA-pp and TSA-DC was reduced from 4.5 (± 2.5) and 2.5 (±0.6) °C, respectively, to 0.8 (± 0.7) and 0.09 (± 0.2) °C. This in vivo study showed the level of noise in PRFS-based thermometry introduced by respiratory motion in the context of MRgHIFU hyperthermia treatment for head and neck and the feasibility of reducing this noise using a multi-baseline technique.

Combined ultrasound and MR imaging to guide focused ultrasound therapies in the brain

NASA Astrophysics Data System (ADS)

Arvanitis, Costas D.; Livingstone, Margaret S.; McDannold, Nathan

2013-07-01

Several emerging therapies with potential for use in the brain, harness effects produced by acoustic cavitation—the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood-brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. While preliminary, these data clearly demonstrate, for the first time, that it is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood-brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate that it will also prove to be an important research tool that will further the development of a broad range of microbubble-enhanced therapies.

Focused ultrasound delivery of Raman nanoparticles across the blood-brain barrier: Potential for targeting experimental brain tumors

PubMed Central

Diaz, Roberto Jose; McVeigh, Patrick Z.; O’Reilly, Meaghan A.; Burrell, Kelly; Bebenek, Matthew; Smith, Christian; Etame, Arnold; Zadeh, Gelareh; Hynynen, Kullervo; Wilson, Brian C.; Rutka, James T.

2014-01-01

Spectral mapping of nanoparticles with surface enhanced Raman scattering (SERS) capability in the near-infrared range is an emerging molecular imaging technique. We used magnetic resonance image-guided transcranial focused ultrasound (TcMRgFUS) to reversibly disrupt the blood-brain barrier (BBB) adjacent to brain tumor margins in rats. Glioma cells were found to internalize SERS capable nanoparticles of 50 nm or 120 nm physical diameter. Surface coating with anti-epidermal growth factor receptor antibody or non-specific human immunoglobulin G, resulted in enhanced cell uptake of nanoparticles in-vitro compared to nanoparticles with methyl terminated 12-unit polyethylene glycol surface. BBB disruption permitted the delivery of SERS capable spherical 50 or 120 nm gold nanoparticles to the tumor margins. Thus, nanoparticles with SERS imaging capability can be delivered across the BBB non-invasively using TcMRgFUS and have the potential to be used as optical tracking agents at the invasive front of malignant brain tumors. PMID:24374363

The role of cortistatin in the human immune system.

PubMed

van Hagen, P Martin; Dalm, Virgil A; Staal, Frank; Hofland, Leo J

2008-05-14

Cortistatin (CST) is a recently described neuropeptide that shares high homology with somatostatin (somatotropin release-inhibiting factor, SRIF) and binds with high affinity to all somatostatin (sst) receptor subtypes. CST is currently known to have a widespread distribution in many human organs including the immune system. The activities specific to CST may be partially attributable to its binding to the growth hormone secretagogue (GHS)-receptor (GHS-R) and the orphan G-protein-coupled receptor MrgX2. Human immune cells produce CST, whereas macrophage lineage and activated endothelium express sst2, and human lymphocytes express sst3. The human thymus expresses sst1, 2, 3, MrgX2 and almost all immune cells express GHS-R. Moreover, at this very moment promising research with CST in experimental animal models is being performed. On the basis of these promising results, studies aiming to further evaluate the possibilities of CST as a therapeutic agent in human immune-mediated inflammatory diseases are warranted.

Review of MRI positioning devices for guiding focused ultrasound systems.

PubMed

Yiallouras, C; Damianou, C

2015-06-01

This article contains a review of positioning devices that are currently used in the area of magnetic resonance imaging (MRI) guided focused ultrasound surgery (MRgFUS). The paper includes an extensive review of literature published since the first prototype system was invented in 1991. The technology has grown into a fast developing area with application to any organ accessible to ultrasound. The initial design operated using hydraulic principles, while the latest technology incorporates piezoelectric motors. Although, in the beginning there were fears regarding MRI safety, during recent years, the deployment of MR-safe positioning devices in FUS has become routine. Many of these positioning devices are now undergoing testing in clinical trials. Existing MRgFUS systems have been utilized mostly in oncology (fibroids, brain, liver, kidney, bone, pancreas, eye, thyroid, and prostate). It is anticipated that, in the near future, there will be a positioning device for every organ that is accessible by focused ultrasound. Copyright © 2014 John Wiley & Sons, Ltd.

A Survey of Synoptic Waves over West Africa

NASA Astrophysics Data System (ADS)

Cheng, Yuan-Ming; Thorncroft, Chris D.; Kiladis, George N.

2017-04-01

Motivated by the pronounced wave-to-wave variability in African easterly wave (AEW) circulation, the three-dimensional structure of synoptic waves over West Africa is revisited with an Empirical Orthogonal Function (EOF) approach to isolate the dominant wave pattern. In this talk we present results of EOF analyses conducted with brightness temperature (Tb) derived from satellite observation and meridional wind at multiple levels from reanalysis data to examine the characteristics and variability of synoptic waves. The structure of waves is extracted by projecting the wind fields and Tb onto the principle components associated with EOF patterns of appropriately filtered parameters. The Tb EOF shows a confined AEW circulation centered around 7.5°N and a distinct evolution of convection within the wave in line with previous research. However, in striking contrast to the confined flow pattern in the Tb EOF, the EOF of 700-hPa meridional wind is distinguished by a meridionally broad AEW circulation. While the peak in circulation is centered around 10°N, there is marked cross-equatorial flow that is associated with an antisymmetric geopotential signature across the equator. This suggests the presence of a mixed Rossby-gravity wave (MRG) structure consistent with Matsuno's shallow water theory. Granted that the vast majority of studies on MRGs focus on the central and western Pacific region, this "hybrid" between AEWs and MRGs over West Africa and Atlantic sector has received little attention and more work regarding the nature and causes of its wave structure and behavior is needed. In addition, an upper-level synoptic wave is captured by EOFs of 200-hPa meridional wind. The kinematic fields reveal a continental-scale wave straddling the equator that resembles an MRG. This upper-level MRG appears to develop in situ over the Horn of Africa and intensifies as it moves across the continent. The associated lower-level structure shows an AEW-like circulation but with a larger spatial extent. This finding motivates the need for more in-depth investigations of synoptic wave variability over the region including an assessment of the direction of causality between the upper-level MRG and the lower-level AEW. This study highlights the various synoptic wave structures over West Africa and their interaction with AEWs. The results suggest the variability of AEW activity could be modulated by, in addition to the large-scale environment, other synoptic waves in the region. We will pursue the EOF approach to shed light on the characteristics and causes of the variability in synoptic wave activity over West Africa.

Three-Dimensional Dosimetric Validation of a Magnetic Resonance Guided Intensity Modulated Radiation Therapy System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rankine, Leith J., E-mail: Leith_Rankine@med.unc.edu; Department of Radiation Oncology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Mein, Stewart

Purpose: To validate the dosimetric accuracy of a commercially available magnetic resonance guided intensity modulated radiation therapy (MRgIMRT) system using a hybrid approach: 3-dimensional (3D) measurements and Monte Carlo calculations. Methods and Materials: We used PRESAGE radiochromic plastic dosimeters with remote optical computed tomography readout to perform 3D high-resolution measurements, following a novel remote dosimetry protocol. We followed the intensity modulated radiation therapy commissioning recommendations of American Association of Physicists in Medicine Task Group 119, adapted to incorporate 3D data. Preliminary tests (“AP” and “3D-Bands”) were delivered to 9.5-cm usable diameter cylindrical PRESAGE dosimeters to validate the treatment planning systemmore » (TPS) for nonmodulated deliveries; assess the sensitivity, uniformity, and rotational symmetry of the PRESAGE dosimeters; and test the robustness of the remote dosimetry protocol. Following this, 4 clinical MRgIMRT plans (“MultiTarget,” “Prostate,” “Head/Neck,” and “C-Shape”) were measured using 13-cm usable diameter PRESAGE dosimeters. For all plans, 3D-γ (3% or 3 mm global, 10% threshold) passing rates were calculated and 3D-γ maps were examined. Point doses were measured with an IBA-CC01 ionization chamber for validation of absolute dose. Finally, by use of an in-house-developed, GPU-accelerated Monte Carlo algorithm (gPENELOPE), we independently calculated dose for all 6 Task Group 119 plans and compared against the TPS. Results: For PRESAGE measurements, 3D-γ analysis yielded passing rates of 98.7%, 99.2%, 98.5%, 98.0%, 99.2%, and 90.7% for AP, 3D-Bands, MultiTarget, Prostate, Head/Neck, and C-Shape, respectively. Ion chamber measurements were within an average of 0.5% (±1.1%) from the TPS dose. Monte Carlo calculations demonstrated good agreement with the TPS, with a mean 3D-γ passing rate of 98.5% ± 1.9% using a stricter 2%/2-mm criterion. Conclusions: We have validated the dosimetric accuracy of a commercial MRgIMRT system using high-resolution 3D techniques. We have demonstrated for the first time that hybrid 3D remote dosimetry is a comprehensive and feasible approach to commissioning MRgIMRT. This may provide better sensitivity in error detection compared with standard 2-dimensional measurements and could be used when implementing complex new magnetic resonance guided radiation therapy technologies.« less

Cavitation-enhanced nonthermal ablation in deep brain targets: feasibility in a large animal model.

PubMed

Arvanitis, Costas D; Vykhodtseva, Natalia; Jolesz, Ferenc; Livingstone, Margaret; McDannold, Nathan

2016-05-01

OBJECT Transcranial MRI-guided focused ultrasound (TcMRgFUS) is an emerging noninvasive alternative to surgery and radiosurgery that is undergoing testing for tumor ablation and functional neurosurgery. The method is currently limited to central brain targets due to skull heating and other factors. An alternative ablative approach combines very low intensity ultrasound bursts and an intravenously administered microbubble agent to locally destroy the vasculature. The objective of this work was to investigate whether it is feasible to use this approach at deep brain targets near the skull base in nonhuman primates. METHODS In 4 rhesus macaques, targets near the skull base were ablated using a clinical TcMRgFUS system operating at 220 kHz. Low-duty-cycle ultrasound exposures (sonications) were applied for 5 minutes in conjunction with the ultrasound contrast agent Definity, which was administered as a bolus injection or continuous infusion. The acoustic power level was set to be near the inertial cavitation threshold, which was measured using passive monitoring of the acoustic emissions. The resulting tissue effects were investigated with MRI and with histological analysis performed 3 hours to 1 week after sonication. RESULTS Thirteen targets were sonicated in regions next to the optic tract in the 4 animals. Inertial cavitation, indicated by broadband acoustic emissions, occurred at acoustic pressure amplitudes ranging from 340 to 540 kPa. MRI analysis suggested that the lesions had a central region containing red blood cell extravasations that was surrounded by edema. Blood-brain barrier disruption was observed on contrast-enhanced MRI in the lesions and in a surrounding region corresponding to the prefocal area of the FUS system. In histology, lesions consisting of tissue undergoing ischemic necrosis were found in all regions that were sonicated above the inertial cavitation threshold. Tissue damage in prefocal areas was found in several cases, suggesting that in those cases the sonication exceeded the inertial cavitation threshold in the beam path. CONCLUSIONS It is feasible to use a clinical TcMRgFUS system to ablate skull base targets in nonhuman primates at time-averaged acoustic power levels at least 2 orders of magnitude below what is needed for thermal ablation with this device. The results point to the risks associated with the method if the exposure levels are not carefully controlled to avoid inertial cavitation in the acoustic beam path. If methods can be developed to provide this control, this nonthermal approach could greatly expand the use of TcMRgFUS for precisely targeted ablation to locations across the entire brain.

Prediction of metastable metal-rare gas fluorides: FMRgF (M=Be and Mg; Rg=Ar, Kr and Xe).

PubMed

Jayasekharan, T; Ghanty, T K

2008-04-14

The structure, stability, charge redistribution, bonding, and harmonic vibrational frequencies of rare gas containing group II-A fluorides with the general formula FMRgF (where M=Be and Mg; Rg=Ar, Kr, and Xe) have been investigated using second order Møller-Plesset perturbation theory, density functional theory, and coupled cluster theory [CCSD(T)] methods. The species, FMRgF show a quasilinear structure at the minima and a bent structure at the transition state. The predicted species are unstable with respect to the two-body dissociation channel, leading to the global minima (MF2+Rg) on the singlet potential energy surface. However, with respect to other two-body dissociation channel (FM+RgF), they are found to be stable and have high positive energies on the same surface. The computed binding energy for the two-body dissociation channels are 94.0, 164.7, and 199.7 kJ mol(-1) for FBeArF, FBeKrF, FBeXeF, respectively, at CCSD(T) method. The corresponding energy values are 83.4, 130.7, and 180.1 kJ mol(-1) for FMgArF, FMgKrF, and FMgXeF, respectively, at the same level of theory. With respect to the three-body dissociation (FM+Rg+F) channel as well as dissociation into atomic constituent, they are also found to be stable and have high positive energies. The dissociation of the predicted species typically proceeds via MRgF bending mode at the transition state. The computed barrier heights for the transition states are 11.4, 32.2, and 57.6 kJ mol(-1) for FBeArF, FBeKrF, and FBeXeF, respectively, at the CCSD(T) method. The corresponding barrier heights for the Mg containing species are 2.1, 9.2, and 32.1 kJ mol(-1) along the series Ar--Kr--Xe, respectively. The M--Rg bond energies of the FMRgF species is significantly higher than the corresponding bond energies of the M+--Rg species ( approximately 53 and approximately 15 kJ mol(-1) for Be+--Ar and Mg+--Ar, respectively). The computed energy diagram as well as the geometrical parameters along with the AIM results suggest that the species are metastable with partial covalent character in the M--Rg bonding. Thus, it may be possible to prepare and to characterize these species using low temperature matrix isolation technique.

Chemical Carcinogen-Induced Changes in tRNA Metabolism in Human Cells

DTIC Science & Technology

1982-11-01

R.W.T., M.S.E.) Department of Medical Microbiology & Immunology (R.G.) Department of Medicine (M.R.G.) The Ohio State University Columbus, Ohio...1973): The measurement of radioactive precursor incorporation into small monolayer cultures. In: Methods In Cell Bioloqy, edited by D.M. Prescott , Vol

Predicting velocity in bendway weir eddy fields

Treesearch

Kristoph-Dietrich Kinzli; Christopher I. Thornton

2010-01-01

Rehabilitation of the Middle Rio Grande (MRG) in central New Mexico has become necessary because of changes in morphology resulting from the installation of dams, and because of habitat restoration considerations for the endangered Rio Grande silvery minnow (Hybognathus amarus). Bendway weirs are erosion control and channel-stabilization structures placed transverse to...

Application of Zernike polynomials towards accelerated adaptive focusing of transcranial high intensity focused ultrasound.

PubMed

Kaye, Elena A; Hertzberg, Yoni; Marx, Michael; Werner, Beat; Navon, Gil; Levoy, Marc; Pauly, Kim Butts

2012-10-01

To study the phase aberrations produced by human skulls during transcranial magnetic resonance imaging guided focused ultrasound surgery (MRgFUS), to demonstrate the potential of Zernike polynomials (ZPs) to accelerate the adaptive focusing process, and to investigate the benefits of using phase corrections obtained in previous studies to provide the initial guess for correction of a new data set. The five phase aberration data sets, analyzed here, were calculated based on preoperative computerized tomography (CT) images of the head obtained during previous transcranial MRgFUS treatments performed using a clinical prototype hemispherical transducer. The noniterative adaptive focusing algorithm [Larrat et al., "MR-guided adaptive focusing of ultrasound," IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57(8), 1734-1747 (2010)] was modified by replacing Hadamard encoding with Zernike encoding. The algorithm was tested in simulations to correct the patients' phase aberrations. MR acoustic radiation force imaging (MR-ARFI) was used to visualize the effect of the phase aberration correction on the focusing of a hemispherical transducer. In addition, two methods for constructing initial phase correction estimate based on previous patient's data were investigated. The benefits of the initial estimates in the Zernike-based algorithm were analyzed by measuring their effect on the ultrasound intensity at the focus and on the number of ZP modes necessary to achieve 90% of the intensity of the nonaberrated case. Covariance of the pairs of the phase aberrations data sets showed high correlation between aberration data of several patients and suggested that subgroups can be based on level of correlation. Simulation of the Zernike-based algorithm demonstrated the overall greater correction effectiveness of the low modes of ZPs. The focal intensity achieves 90% of nonaberrated intensity using fewer than 170 modes of ZPs. The initial estimates based on using the average of the phase aberration data from the individual subgroups of subjects was shown to increase the intensity at the focal spot for the five subjects. The application of ZPs to phase aberration correction was shown to be beneficial for adaptive focusing of transcranial ultrasound. The skull-based phase aberrations were found to be well approximated by the number of ZP modes representing only a fraction of the number of elements in the hemispherical transducer. Implementing the initial phase aberration estimate together with Zernike-based algorithm can be used to improve the robustness and can potentially greatly increase the viability of MR-ARFI-based focusing for a clinical transcranial MRgFUS therapy.

Feasibility of Adaptive MR-guided Stereotactic Body Radiotherapy (SBRT) of Lung Tumors

PubMed Central

Simpson, Garrett N; Llorente, Ricardo; Samuels, Michael A; Dogan, Nesrin

2018-01-01

Online adaptive radiotherapy (ART) with frequent imaging has the potential to improve dosimetric accuracy by accounting for anatomical and functional changes during the course of radiotherapy. Presented are three interesting cases that provide an assessment of online adaptive magnetic resonance-guided radiotherapy (MRgRT) for lung stereotactic body radiotherapy (SBRT). The study includes three lung SBRT cases, treated on an MRgRT system where MR images were acquired for planning and prior to each treatment fraction. Prescription dose ranged from 48 to 50 Gy in four to five fractions, normalized to where 95% of the planning target volume (PTV) was covered by 100% of the prescription dose. The process begins with the gross tumor volume (GTV), PTV, spinal cord, lungs, heart, and esophagus being delineated on the planning MRI. The treatment plan was then generated using a step-and-shoot intensity modulated radiotherapy (IMRT) technique, which utilized a Monte Carlo dose calculation. Next, the target and organs at risk (OAR) contours from the planning MRI were deformably propagated to the daily setup MRIs. These deformed contours were reviewed and modified by the physician. To determine the efficacy of ART, two different strategies were explored: 1) Calculating the plan created for the planning MR on each fraction setup MR dataset (Non-Adapt) and 2) creating a new optimized IMRT plan on the fraction setup MR dataset (FxAdapt). The treatment plans from both strategies were compared using the clinical dose-volume constraints. PTV coverage constraints were not met for 33% Non-Adapt fractions; all FxAdapt fractions met this constraint. Eighty-eight percent of all OAR constraints studied were better on FxAdapt plans, while 12% of OAR constraints were superior on Non-Adapt fractions. The OAR that garnered the largest benefit would be the uninvolved lung, with superior sparing in 92% of the FxAdapt studied. Similar, but less pronounced, benefits from adaptive planning were experienced for the spinal cord, chest wall, and esophagus. Online adaptive MR-guided lung SBRT can provide better target conformality and homogeneity and OAR sparing compared with non-adaptive SBRT in selected cases. Conversely, if the PTV isn’t adjacent to multiple OARs, then the benefit from ART may be limited. Further studies, which incorporate a larger cohort of patients with uniform prescriptions, are needed to thoroughly evaluate the benefits of daily online ART during MRgRT. PMID:29872603

Analysis of Magnetic Resonance Image Signal Fluctuations Acquired During MR-Guided Radiotherapy

PubMed Central

Breto, Adrian L; Padgett, Kyle R; Ford, John C; Kwon, Deukwoo; Chang, Channing; Fuss, Martin; Mellon, Eric A

2018-01-01

Magnetic resonance-guided radiotherapy (MRgRT) is a new and evolving treatment modality that allows unprecedented visualization of the tumor and surrounding anatomy. MRgRT includes daily 3D magnetic resonance imaging (MRI) for setup and rapidly repeated near real-time MRI scans during treatment for target tracking. One of the more exciting potential benefits of MRgRT is the ability to analyze serial MRIs to monitor treatment response or predict outcomes. A typical radiation treatment (RT) over the span of 10-15 minutes on the MRIdian system (ViewRay, Cleveland, OH) yields thousands of “cine” images, each acquired in 250 ms. This unique data allows for a glimpse in image intensity changes during RT delivery. In this report, we analyze cine images from a single fraction RT of a glioblastoma patient on the ViewRay platform in order to characterize the dynamic signal changes occurring during RT therapy. The individual frames in the cines were saved into DICOM format and read into an MIM image analysis platform (MIM Software, Cleveland, OH) as a time series. The three possible states of the three Cobalt-60 radiation sources—OFF, READY, and ON—were also recorded. An in-house Java plugin for MIM was created in order to perform principal component analysis (PCA) on each of the datasets. The analysis resulted in first PC, related to monotonous signal increase over the course of the treatment fraction. We found several distortion patterns in the data that we postulate result from the perturbation of the magnetic field due to the moving metal parts in the platform while treatment was being administered. The largest variations were detected when all Cobalt-60 sources were OFF. During this phase of the treatment, the gantry and multi-leaf collimators (MLCs) are moving. Conversely, when all Cobalt-60 sources were in the ON position, the image signal fluctuations were minimal, relating to very little mechanical motion. At this phase, the gantry, the MLCs, and sources are fixed in their positions. These findings were confirmed in a study with the daily quality assurance (QA) phantom. While the identified variations were not related to physiological processes, our findings confirm the sensitivity of the developed approach to identify very small fluctuations. Relating these variations to the physical changes that occur during treatment shows the methodical ability of the technique to uncover their underlying sources. PMID:29850380

Application of Zernike polynomials towards accelerated adaptive focusing of transcranial high intensity focused ultrasound

PubMed Central

Kaye, Elena A.; Hertzberg, Yoni; Marx, Michael; Werner, Beat; Navon, Gil; Levoy, Marc; Pauly, Kim Butts

2012-01-01

Purpose: To study the phase aberrations produced by human skulls during transcranial magnetic resonance imaging guided focused ultrasound surgery (MRgFUS), to demonstrate the potential of Zernike polynomials (ZPs) to accelerate the adaptive focusing process, and to investigate the benefits of using phase corrections obtained in previous studies to provide the initial guess for correction of a new data set. Methods: The five phase aberration data sets, analyzed here, were calculated based on preoperative computerized tomography (CT) images of the head obtained during previous transcranial MRgFUS treatments performed using a clinical prototype hemispherical transducer. The noniterative adaptive focusing algorithm [Larrat , “MR-guided adaptive focusing of ultrasound,” IEEE Trans. Ultrason. Ferroelectr. Freq. Control 57(8), 1734–1747 (2010)]10.1109/TUFFC.2010.1612 was modified by replacing Hadamard encoding with Zernike encoding. The algorithm was tested in simulations to correct the patients’ phase aberrations. MR acoustic radiation force imaging (MR-ARFI) was used to visualize the effect of the phase aberration correction on the focusing of a hemispherical transducer. In addition, two methods for constructing initial phase correction estimate based on previous patient's data were investigated. The benefits of the initial estimates in the Zernike-based algorithm were analyzed by measuring their effect on the ultrasound intensity at the focus and on the number of ZP modes necessary to achieve 90% of the intensity of the nonaberrated case. Results: Covariance of the pairs of the phase aberrations data sets showed high correlation between aberration data of several patients and suggested that subgroups can be based on level of correlation. Simulation of the Zernike-based algorithm demonstrated the overall greater correction effectiveness of the low modes of ZPs. The focal intensity achieves 90% of nonaberrated intensity using fewer than 170 modes of ZPs. The initial estimates based on using the average of the phase aberration data from the individual subgroups of subjects was shown to increase the intensity at the focal spot for the five subjects. Conclusions: The application of ZPs to phase aberration correction was shown to be beneficial for adaptive focusing of transcranial ultrasound. The skull-based phase aberrations were found to be well approximated by the number of ZP modes representing only a fraction of the number of elements in the hemispherical transducer. Implementing the initial phase aberration estimate together with Zernike-based algorithm can be used to improve the robustness and can potentially greatly increase the viability of MR-ARFI-based focusing for a clinical transcranial MRgFUS therapy. PMID:23039661

78 FR 42497 - Certain Frozen Warmwater Shrimp From Thailand: Final Results of Antidumping Duty Administrative...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-16

... Shrimp From Thailand: Final Results of Antidumping Duty Administrative Review, Partial Rescission of... frozen warmwater shrimp (shrimp) from Thailand. The period of review (POR) is February 1, 2011, through... Thailand produced and exported by Marine Gold Products Limited (MRG) and to rescind the review with respect...

Activity of convective coupled equatorial wave in tropical Tropopause layer in reanalysis and high-top CMIP5 models

NASA Astrophysics Data System (ADS)

Harza, Alia; Lubis, Sandro W.; Setiawan, Sonni

2018-05-01

The activity of convectively coupled equatorial waves (CCEWs), including Kelvin waves, Mixed Rossby-Gravity (MRG), and Equatorial Rossby (ER), in the tropical tropopause layer (TTL) is investigated in the Reanalysis and nine high-top CMIP5 models using the zonal wave number-frequency spectral analysis with equatorially symmetric-antisymmetric decomposition. We found that the TTL activities in the high-top CMIP5 models show significant difference among the high-top CMIP5 models with respect to the observation. The MIROC and HadGEM2-CC models work best in simulating Kelvin wave in the TTL, while the HadGEM2-CC and MPI-ESM-LR models work best in simulating MRG waves. The ER waves in TTL are best simulated in the MRI-CGCM model. None of the models are good in simulating all waves at once. It is concluded that the broad range of wave activity found in the different CMIP5 models depend on the convective parameterization used by each model and the representation of the tropical stratosphere variability, including the QBO.

WE-G-12A-01: High Intensity Focused Ultrasound Surgery and Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farahani, K; O'Neill, B

More and more emphasis is being made on alternatives to invasive surgery and the use of ionizing radiation to treat various diseases including cancer. Novel screening, diagnosis, treatment and monitoring of response to treatment are also hot areas of research and new clinical technologies. Ultrasound(US) has gained traction in all of the aforementioned areas of focus. Especially with recent advances in the use of ultrasound to noninvasively treat various diseases/organ systems. This session will focus on covering MR-guided focused ultrasound and the state of the art clinical applications, and the second speaker will survey the more cutting edge technologies e.g.more » Focused Ultrasound (FUS) mediated drug delivery, principles of cavitation and US guided FUS. Learning Objectives: Fundamental physics and physical limitations of US interaction with tissue and nanoparticles The alteration of tissue transport using focused ultrasound US control of nanoparticle drug carriers for targeted release The basic principles of MRI-guided focused ultrasound (MRgFUS) surgery and therapy the current state of the art clinical applications of MRgFUS requirements for quality assurance and treatment planning.« less

Enhancements to the Branched Lagrangian Transport Modeling System

USGS Publications Warehouse

Jobson, Harvey E.

1997-01-01

The Branched Lagrangian Transport Model (BLTM) has received wide use within the U.S. Geological Survey over the past 10 years. This report documents the enhancements and modifications that have been made to this modeling system since it was first introduced. The programs in the modeling system are arranged into five levels?programs to generate time-series of meteorological data (EQULTMP, SOLAR), programs to process time-series data (INTRP, MRG), programs to build input files for transport model (BBLTM, BQUAL2E), the model with defined reaction kinetics (BLTM, QUAL2E), and post processor plotting programs (CTPLT, CXPLT). An example application is presented to illustrate how the modeling system can be used to simulate 10 water-quality constituents in the Chattahoochee River below Atlanta, Georgia.

Combined Ultrasound and MR Imaging to Guide Focused Ultrasound Therapies in the Brain

PubMed Central

Arvanitis, Costas D.; Livingstone, Margaret S.; McDannold, Nathan

2013-01-01

Purpose Several emerging therapies with potential for use in the brain harness effects produced by acoustic cavitation – the interaction between ultrasound and microbubbles either generated during sonication or introduced into the vasculature. Systems developed for transcranial MRI-guided focused ultrasound (MRgFUS) thermal ablation can enable their clinical translation, but methods for real-time monitoring and control are currently lacking. Acoustic emissions produced during sonication can provide information about the location, strength, and type of the microbubble oscillations within the ultrasound field, and they can be mapped in real-time using passive imaging approaches. Here, we tested whether such mapping can be achieved transcranially within a clinical brain MRgFUS system. Materials and Methods We integrated an ultrasound imaging array into the hemisphere transducer of the MRgFUS device. Passive cavitation maps were obtained during sonications combined with a circulating microbubble agent at 20 targets in the cingulate cortex in three macaques. The maps were compared with MRI-evident tissue effects. Results The system successfully mapped microbubble activity during both stable and inertial cavitation, which was correlated with MRI-evident transient blood-brain barrier disruption and vascular damage, respectively. The location of this activity was coincident with the resulting tissue changes within the expected resolution limits of the system. Conclusion While preliminary, these data clearly demonstrate, for the first time, that is possible to construct maps of stable and inertial cavitation transcranially, in a large animal model, and under clinically relevant conditions. Further, these results suggest that this hybrid ultrasound/MRI approach can provide comprehensive guidance for targeted drug delivery via blood-brain barrier disruption and other emerging ultrasound treatments, facilitating their clinical translation. We anticipate it will also prove to be an important research tool that will further the development of a broad range of microbubble-enhanced therapies. PMID:23788054

Methanol May Function as a Cross-Kingdom Signal

PubMed Central

Dorokhov, Yuri L.; Komarova, Tatiana V.; Petrunia, Igor V.; Kosorukov, Vyacheslav S.; Zinovkin, Roman A.; Shindyapina, Anastasia V.; Frolova, Olga Y.; Gleba, Yuri Y.

2012-01-01

Recently, we demonstrated that leaf wounding results in the synthesis of pectin methylesterase (PME), which causes the plant to release methanol into the air. Methanol emitted by a wounded plant increases the accumulation of methanol-inducible gene mRNA and enhances antibacterial resistance as well as cell-to-cell communication, which facilitates virus spreading in neighboring plants. We concluded that methanol is a signaling molecule involved in within-plant and plant-to-plant communication. Methanol is considered to be a poison in humans because of the alcohol dehydrogenase (ADH)-mediated conversion of methanol into toxic formaldehyde. However, recent data showed that methanol is a natural compound in normal, healthy humans. These data call into question whether human methanol is a metabolic waste product or whether methanol has specific function in humans. Here, to reveal human methanol-responsive genes (MRGs), we used suppression subtractive hybridization cDNA libraries of HeLa cells lacking ADH and exposed to methanol. This design allowed us to exclude genes involved in formaldehyde and formic acid detoxification from our analysis. We identified MRGs and revealed a correlation between increases in methanol content in the plasma and changes in human leukocyte MRG mRNA levels after fresh salad consumption by volunteers. Subsequently, we showed that the methanol generated by the pectin/PME complex in the gastrointestinal tract of mice induces the up- and downregulation of brain MRG mRNA. We used an adapted Y-maze to measure the locomotor behavior of the mice while breathing wounded plant vapors in two-choice assays. We showed that mice prefer the odor of methanol to other plant volatiles and that methanol changed MRG mRNA accumulation in the mouse brain. We hypothesize that the methanol emitted by wounded plants may have a role in plant-animal signaling. The known positive effect of plant food intake on human health suggests a role for physiological methanol in human gene regulation. PMID:22563443

Predicting variation in subject thermal response during transcranial magnetic resonance guided focused ultrasound surgery: Comparison in seventeen subject datasets.

PubMed

Vyas, Urvi; Ghanouni, Pejman; Halpern, Casey H; Elias, Jeff; Pauly, Kim Butts

2016-09-01

In transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) treatments, the acoustic and spatial heterogeneity of the skull cause reflection, absorption, and scattering of the acoustic beams. These effects depend on skull-specific parameters and can lead to patient-specific thermal responses to the same transducer power. In this work, the authors develop a simulation tool to help predict these different experimental responses using 3D heterogeneous tissue models based on the subject CT images. The authors then validate and compare the predicted skull efficiencies to an experimental metric based on the subject thermal responses during tcMRgFUS treatments in a dataset of seventeen human subjects. Seventeen human head CT scans were used to create tissue acoustic models, simulating the effects of reflection, absorption, and scattering of the acoustic beam as it propagates through a heterogeneous skull. The hybrid angular spectrum technique was used to model the acoustic beam propagation of the InSightec ExAblate 4000 head transducer for each subject, yielding maps of the specific absorption rate (SAR). The simulation assumed the transducer was geometrically focused to the thalamus of each subject, and the focal SAR at the target was used as a measure of the simulated skull efficiency. Experimental skull efficiency for each subject was calculated using the thermal temperature maps from the tcMRgFUS treatments. Axial temperature images (with no artifacts) were reconstructed with a single baseline, corrected using a referenceless algorithm. The experimental skull efficiency was calculated by dividing the reconstructed temperature rise 8.8 s after sonication by the applied acoustic power. The simulated skull efficiency using individual-specific heterogeneous models predicts well (R(2) = 0.84) the experimental energy efficiency. This paper presents a simulation model to predict the variation in thermal responses measured in clinical ctMRGFYS treatments while being computationally feasible.

Trophic transfer of trace metals: Subcellular compartmentalization in a polychaete and assimilation by a decapod crustacean

USGS Publications Warehouse

Rainbow, P.S.; Poirier, L.; Smith, B.D.; Brix, K.V.; Luoma, S.N.

2006-01-01

The chemical form of accumulated trace metal in prey is important in controlling the bioavailataility of dietary metal to a predator. This study investigated the trophic transfer of radiolabelled Ag, Cd and Zn from the polychaete worm Nereis diversicolor to the decapod crustacean Palaemonetes varians. We used 2 populations of worms with different proportions of accumulated metals in different subcellular fractions as prey, and loaded the worms with radiolabelled metals either from sediment or from solution. Accumulated radiolabelled metals were fractionated into 5 components : metal-rich granules (MRG), cellular debris, organelles, metallothionein-like proteins (MTLP), and other (heat-sensitive) proteins (HSP). Assimilation efficiencies (AE) of the metals by P. varians were measured from the 4 categories of prey (i.e. 2 populations, radiolabelled from sediment or solution). There were significant differences for each metal between the AEs from the different prey categories, confirming that origin of prey and route of uptake of accumulated trace metal will cause intraspecific differences in subsequent metal assimilation. Correlations were sought between AEs and selected fractions or combinations of fractions of metals in the prey-MRG, Trophically Available Metal (TAM = MTLP + HSP + organelles) and total protein (MTLP + HSP). TAM explained 28% of the variance in AEs for Ag, but no consistent relationships emerged between AEs and TAM or total protein when the metals were considered separately. AEs did, however, show significant positive regressions with both TAM and total protein when the 3 metals were considered together, explaining only about 21 % of the variance in each case. A significant negative relationship was observed between MRG and AE for all metals combined. The predator (P. varians) can assimilate dietary metal from a range of the fractions binding metals in the prey (N. diversicolor), with different assimilation efficiencies summated across these fractions. TAM and/or total protein may represent an approximate minimum for trophic availability but neither of these alone is a fully accurate predictor. ?? Inter-Research 2006.

Predicting variation in subject thermal response during transcranial magnetic resonance guided focused ultrasound surgery: Comparison in seventeen subject datasets

PubMed Central

Vyas, Urvi; Ghanouni, Pejman; Halpern, Casey H.; Elias, Jeff; Pauly, Kim Butts

2016-01-01

Purpose: In transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) treatments, the acoustic and spatial heterogeneity of the skull cause reflection, absorption, and scattering of the acoustic beams. These effects depend on skull-specific parameters and can lead to patient-specific thermal responses to the same transducer power. In this work, the authors develop a simulation tool to help predict these different experimental responses using 3D heterogeneous tissue models based on the subject CT images. The authors then validate and compare the predicted skull efficiencies to an experimental metric based on the subject thermal responses during tcMRgFUS treatments in a dataset of seventeen human subjects. Methods: Seventeen human head CT scans were used to create tissue acoustic models, simulating the effects of reflection, absorption, and scattering of the acoustic beam as it propagates through a heterogeneous skull. The hybrid angular spectrum technique was used to model the acoustic beam propagation of the InSightec ExAblate 4000 head transducer for each subject, yielding maps of the specific absorption rate (SAR). The simulation assumed the transducer was geometrically focused to the thalamus of each subject, and the focal SAR at the target was used as a measure of the simulated skull efficiency. Experimental skull efficiency for each subject was calculated using the thermal temperature maps from the tcMRgFUS treatments. Axial temperature images (with no artifacts) were reconstructed with a single baseline, corrected using a referenceless algorithm. The experimental skull efficiency was calculated by dividing the reconstructed temperature rise 8.8 s after sonication by the applied acoustic power. Results: The simulated skull efficiency using individual-specific heterogeneous models predicts well (R2 = 0.84) the experimental energy efficiency. Conclusions: This paper presents a simulation model to predict the variation in thermal responses measured in clinical ctMRGFYS treatments while being computationally feasible. PMID:27587047

Predicting variation in subject thermal response during transcranial magnetic resonance guided focused ultrasound surgery: Comparison in seventeen subject datasets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vyas, Urvi, E-mail: urvi.vyas@gmail.com; Ghanouni,

Purpose: In transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) treatments, the acoustic and spatial heterogeneity of the skull cause reflection, absorption, and scattering of the acoustic beams. These effects depend on skull-specific parameters and can lead to patient-specific thermal responses to the same transducer power. In this work, the authors develop a simulation tool to help predict these different experimental responses using 3D heterogeneous tissue models based on the subject CT images. The authors then validate and compare the predicted skull efficiencies to an experimental metric based on the subject thermal responses during tcMRgFUS treatments in a dataset of seventeen humanmore » subjects. Methods: Seventeen human head CT scans were used to create tissue acoustic models, simulating the effects of reflection, absorption, and scattering of the acoustic beam as it propagates through a heterogeneous skull. The hybrid angular spectrum technique was used to model the acoustic beam propagation of the InSightec ExAblate 4000 head transducer for each subject, yielding maps of the specific absorption rate (SAR). The simulation assumed the transducer was geometrically focused to the thalamus of each subject, and the focal SAR at the target was used as a measure of the simulated skull efficiency. Experimental skull efficiency for each subject was calculated using the thermal temperature maps from the tcMRgFUS treatments. Axial temperature images (with no artifacts) were reconstructed with a single baseline, corrected using a referenceless algorithm. The experimental skull efficiency was calculated by dividing the reconstructed temperature rise 8.8 s after sonication by the applied acoustic power. Results: The simulated skull efficiency using individual-specific heterogeneous models predicts well (R{sup 2} = 0.84) the experimental energy efficiency. Conclusions: This paper presents a simulation model to predict the variation in thermal responses measured in clinical ctMRGFYS treatments while being computationally feasible.« less

Respiratory motion-resolved, self-gated 4D-MRI using Rotating Cartesian K-space (ROCK): Initial clinical experience on an MRI-guided radiotherapy system.

PubMed

Han, Fei; Zhou, Ziwu; Du, Dongsu; Gao, Yu; Rashid, Shams; Cao, Minsong; Shaverdian, Narek; Hegde, John V; Steinberg, Michael; Lee, Percy; Raldow, Ann; Low, Daniel A; Sheng, Ke; Yang, Yingli; Hu, Peng

2018-06-01

To optimize and evaluate the respiratory motion-resolved, self-gated 4D-MRI using Rotating Cartesian K-space (ROCK-4D-MRI) method in a 0.35 T MRI-guided radiotherapy (MRgRT) system. The study included seven patients with abdominal tumors treated on the MRgRT system. ROCK-4D-MRI and 2D-CINE, was performed immediately after one of the treatment fractions. Motion quantification based on 4D-MRI was compared with those based on 2D-CINE. The image quality of 4D-MRI was evaluated against 4D-CT. The gross tumor volumes (GTV) were defined based on individual respiratory phases of both 4D-MRI and 4D-CT and compared for their variability over the respiratory cycle. The motion measurements based on 4D-MRI matched well with 2D-CINE, with differences of 1.04 ± 0.52 mm in the superior-inferior and 0.54 ± 0.21 mm in the anterior-posterior directions. The image quality scores of 4D-MRI were significantly higher than 4D-CT, with better tumor contrast (3.29 ± 0.76 vs. 1.86 ± 0.90) and less motion artifacts (3.57 ± 0.53 vs. 2.29 ± 0.95). The GTVs were more consistent in 4D-MRI than in 4D-CT, with significantly smaller GTV variability (9.31 ± 4.58% vs. 34.27 ± 23.33%). Our study demonstrated the clinical feasibility of using the ROCK-4D-MRI to acquire high quality, respiratory motion-resolved 4D-MRI in a low-field MRgRT system. The 4D-MRI image could provide accurate dynamic information for radiotherapy treatment planning. Copyright © 2018 Elsevier B.V. All rights reserved.

Riparian ecohydrology: regulation of water flux from the ground to the atmosphere in the Middle Rio Grande, New Mexico

NASA Astrophysics Data System (ADS)

Cleverly, James R.; Dahm, Clifford N.; Thibault, James R.; McDonnell, Dianne E.; Allred Coonrod, Julie E.

2006-10-01

During the previous decade, the south-western United States has faced declining water resources and escalating forest fires due to long-term regional drought. Competing demands for water resources require a careful accounting of the basin water budget. Water lost to the atmosphere through riparian evapotranspiration (ET) is believed to rank in the top third of water budget depletions. To better manage depletions in a large river system, patterns of riparian ET must be better understood. This paper provides a general overview of the ecological, hydrological, and atmospheric issues surrounding riparian ET in the Middle Rio Grande (MRG) of New Mexico. Long-term measurements of ET, water table depth, and micro-meteorological conditions have been made at sites dominated by native cottonwood (Populus deltoides) forests and non-native saltcedar (Tamarix chinensis) thickets along the MRG. Over periods longer than one week, groundwater and leaf area index (LAI) dynamics relate well with ET rates. Evapotranspiration from P. deltoides forests was unaffected by annual drought conditions in much of the MRG where the water table is maintained within 3 m of the surface. Evapotranspiration from a dense Tamarix chinensis thicket did not decline with increasing groundwater depth; instead, ET increased by 50%, from 6 mm/day to 9 mm/day, as the water table receded at nearly 7 cm/day. Leaf area index of the T. chinensis thicket, likewise, increased during groundwater decline. Leaf area index can be manipulated as well following removal of non-native species. When T. chinensis and non-native Russian olive (Elaeagnus angustifolia) were removed from a P. deltoides understory, water salvaged through reduced ET was 26 cm/yr in relation to ET measured at reference sites. To investigate correlates to short-term variations in ET, stepwise multiple linear regression was used to evaluate atmospheric conditions under which ET is elevated or depressed. At the P. deltoides-dominated sites, ET anomalies were positively correlated to net radiation (Rn) and negatively correlated to sensible heat flux (H), cross-corridor wind speed (v), and along-corridor wind speed (u) (r2 = 0.54). At the T. chinensis-dominated sites, ET anomalies were positively correlated with Rn, u, the friction coefficient (u*), and vapour pressure deficit (VPD) and were negatively correlated to surface humidity scale (q*), daily high and low temperature, H, and precipitation (r2 = 0.66). Both Tamarix and Populus can transpire prodigious quantities of water when conditions are favourable. In the MRG, T. chinensis is preferentially found where summer flooding and cold air drainage occurs, and P. deltoides is preferentially located in areas with shallow groundwater within 2 m of the surface.

War: The Impact on Minority and Indigenous Children. MRG International Report 97/2.

ERIC Educational Resources Information Center

Barnes, Catherine; Chakma, Suhas; Mohamed, Mohamed Hamud Sheikh; Thulin, Kristina Hedlund; Monzon, Ana Silvia; Stockman, Lorne; Sunderland, Judith

In today's internal armed conflicts that pitch one group against another, minority and indigenous children are often seen as "legitimate targets" despite the wealth of international law to the contrary. This report focuses on three recent or current armed conflicts, drawing on interviews with children and others to piece together the…

Groundwater, Vegetation, and Atmosphere: Comparative Riparian Evapotranspiration, Restoration, and Water Salvage

Treesearch

J. R. Cleverly; C. N. Dahm; J. R. Thibault; D. McDonnell; J. E. Allred Coonrod

2006-01-01

As water shortages persist throughout the Western U.S., a great deal of money and effort is directed toward decreasing riparian water loss, thereby enabling continued water use by irrigators, industry, and municipalities. This study focuses upon long-term measurement of evapotranspiration (ET) by native and non-native riparian species along the Middle Rio Grande (MRG)...

Race and Law in Britain and the United States. MRG Report No. 22.

ERIC Educational Resources Information Center

Claiborne, Louis

This report surveys American and British experiences in applying law to problems of race relations, and assesses the achievements and setbacks in each nation. An overview of racial issues in the course of United States and British history, beginning with the slavery issue, provides a perspective on the common and different problems experienced by…

Simulating thermal effects of MR-guided focused ultrasound in cortical bone and its surrounding tissue.

PubMed

Hudson, Thomas J; Looi, Thomas; Pichardo, Samuel; Amaral, Joao; Temple, Michael; Drake, James M; Waspe, Adam C

2018-02-01

Magnetic resonance-guided focused ultrasound (MRgFUS) is emerging as a treatment alternative for osteoid osteoma and painful bone metastases. This study describes a new simulation platform that predicts the distribution of heat generated by MRgFUS when applied to bone tissue. Calculation of the temperature distribution was performed using two mathematical models. The first determined the propagation and absorption of acoustic energy through each medium, and this was performed using a multilayered approximation of the Rayleigh integral method. The ultrasound energy distribution derived from these equations could then be converted to heat energy, and the second mathematical model would then use the heat generated to determine the final temperature distribution using a finite-difference time-domain application of Pennes' bio-heat transfer equation. Anatomical surface geometry was generated using a modified version of a mesh-based semiautomatic segmentation algorithm, and both the acoustic and thermodynamic models were calculated using a parallelized algorithm running on a graphics processing unit (GPU) to greatly accelerate computation time. A series of seven porcine experiments were performed to validate the model, comparing simulated temperatures to MR thermometry and assessing spatial, temporal, and maximum temperature accuracy in the soft tissue. The parallelized algorithm performed acoustic and thermodynamic calculations on grids of over 10 8 voxels in under 30 s for a simulated 20 s of heating and 40 s of cooling, with a maximum time per calculated voxel of less than 0.3 μs. Accuracy was assessed by comparing the soft tissue thermometry to the simulation in the soft tissue adjacent to bone using four metrics. The maximum temperature difference between the simulation and thermometry in a region of interest around the bone was measured to be 5.43 ± 3.51°C average absolute difference and a percentage difference of 16.7%. The difference in heating location resulted in a total root-mean-square error of 4.21 ± 1.43 mm. The total size of the ablated tissue calculated from the thermal dose approximation in the simulation was, on average, 67.6% smaller than measured from the thermometry. The cooldown was much faster in the simulation, where it decreased by 14.22 ± 4.10°C more than the thermometry in 40 s after sonication ended. The use of a Rayleigh-based acoustic model combined with a discretized bio-heat transfer model provided a rapid three-dimensional calculation of the temperature distribution through bone and soft tissue during MRgFUS application, and the parallelized GPU algorithm provided the computational speed that would be necessary for an intraoperative treatment planning software platform. © 2017 American Association of Physicists in Medicine.

Local Governance in Multi-Ethnic Communities of Central and Eastern Europe: A Skills Exchange Workshop (Romania, April 4-7, 1997). Workshop Report.

ERIC Educational Resources Information Center

Minority Rights Group, London (England).

This report describes a skills exchange workshop, co-organized by Minority Rights Group International (MRG) and the Liga Pro Europa, on local governance in multi-ethnic communities in Central and Eastern Europe. Civil servants, members of minority communities, non-governmental organization (NGO) activists, and public officials from Bulgaria,…

The Middle Rio Grande: Its ecology and management

Treesearch

Jeffery C Whitney

1996-01-01

The Middle Rio Grande (MRG) riparian forest, or "bosque", represents the largest cottonwood gallery riparian forest in the southwestern United States. This reach of the Rio Grande extends from Cochiti Dam downstream 260 Km to San Marcial, New Mexico. It constitutes 8% of the river’s total length and 34% of if its length in New Mexico. The valley traverses...

The effects of wildfire on native tree species in the Middle Rio Grande bosques of New Mexico

Treesearch

Brad Johnson; David Merritt

2009-01-01

The cottonwood bosques along the Middle Fork of the Rio Grande (MRG) form a ribbon of surviving habitat in this once vast ecosystem. Historically, the channel had a multi-threaded and braided configuration that created a rich mosaic of habitats, including mixed-aged cottonwood forests, meadows, and willow-dominated riparian wetlands and backwaters (...

Elaboration of nano titania-magnetic reduced graphene oxide for degradation of tartrazine dye in aqueous solution

NASA Astrophysics Data System (ADS)

Nada, Amr A.; Tantawy, Hesham R.; Elsayed, Mohamed A.; Bechelany, Mikhael; Elmowafy, Mohamed E.

2018-04-01

In this paper, magnetic nanocomposites are synthesized by loading reduced graphene oxide (RG) with two components of nanoparticles consisting of titanium dioxide (TiO2) and magnetite (Fe3O4) with varying amounts. The structural and magnetic features of the prepared composite photocatalysts were investigated by powder X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), transmission electron microscopy (TEM), UV-vis diffuse reflectance spectra (UV-vis/DRS), Raman and vibrating sample magnetometer (VSM). The resulting TiO2/magnetite reduced graphene oxide (MRGT) composite demonstrated intrinsic visible light photocatalytic activity, on degradation of tartrazine (TZ) dye from a synthetic aqueous solution. Specifically, it exhibits higher photocatalytic activity than magnetite reduced graphene oxide (MRG) and TiO2 nanoparticles. The photocatalytic degradation of TZ dye when using MRG and TiO2 for 3 h under visible light was 35% and 10% respectively, whereas for MRGT it was more than 95%. The higher photocatalytic efficiency of MRGT is due to the existence of reduced graphene oxide and magnetite which enhances the photocatalytic efficiency of the composite in visible light towards the degradation of harmful soluble azo dye (tartrazine).

Investigation of standing wave formation in a human skull for a clinical prototype of a large-aperture, transcranial MR-guided Focused Ultrasound (MRgFUS) phased array: An experimental and simulation study

PubMed Central

Song, Junho; Pulkkinen, Aki; Huang, Yuexi; Hynynen, Kullervo

2014-01-01

Standing wave formation in an ex vivo human skull was investigated using a clinical prototype of a 30 cm diameter with 15 cm radius of curvature, low frequency (230 kHz), hemispherical transcranial Magnetic Resonance guided Focused Ultrasound (MRgFUS) phased-array. Experimental and simulation studies were conducted with changing aperture size and f-number configurations of the phased array, and qualitatively and quantitatively examined the acoustic pressure variation at the focus due to standing waves. The results demonstrated that the nodes and anti-nodes of standing wave produced by the small aperture array were clearly seen at approximately every 3 mm. The effect of the standing wave became more pronounced as the focus was moved closer to skull base. However, a sharp focus was seen for the full array, and there was no such standing wave pattern in the acoustic plane or near the skull base. This study showed that the fluctuation pressure amplitude would be greatly reduced by using a large-scale, hemispherical phased array with a low f-number. PMID:22049360

Predictive Capability of the Compressible MRG Equation for an Explosively Driven Particle with Validation

NASA Astrophysics Data System (ADS)

Garno, Joshua; Ouellet, Frederick; Koneru, Rahul; Balachandar, Sivaramakrishnan; Rollin, Bertrand

2017-11-01

An analytic model to describe the hydrodynamic forces on an explosively driven particle is not currently available. The Maxey-Riley-Gatignol (MRG) particle force equation generalized for compressible flows is well-studied in shock-tube applications, and captures the evolution of particle force extracted from controlled shock-tube experiments. In these experiments only the shock-particle interaction was examined, and the effects of the contact line were not investigated. In the present work, the predictive capability of this model is considered for the case where a particle is explosively ejected from a rigid barrel into ambient air. Particle trajectory information extracted from simulations is compared with experimental data. This configuration ensures that both the shock and contact produced by the detonation will influence the motion of the particle. The simulations are carried out using a finite volume, Euler-Lagrange code using the JWL equation of state to handle the explosive products. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program,under Contract No. DE-NA0002378.

A Novel Mammalian Complex Containing Sin3B Mitigates Histone Acetylation and RNA Polymerase II Progression within Transcribed Loci▿

PubMed Central

Jelinic, Petar; Pellegrino, Jessica; David, Gregory

2011-01-01

Transcription requires the progression of RNA polymerase II (RNAP II) through a permissive chromatin structure. Recent studies of Saccharomyces cerevisiae have demonstrated that the yeast Sin3 protein contributes to the restoration of the repressed chromatin structure at actively transcribed loci. Yet, the mechanisms underlying the restoration of the repressive chromatin structure at transcribed loci and its significance in gene expression have not been investigated in mammals. We report here the identification of a mammalian complex containing the corepressor Sin3B, the histone deacetylase HDAC1, Mrg15, and the PHD finger-containing Pf1 and show that this complex plays important roles in regulation of transcription. We demonstrate that this complex localizes at discrete loci approximately 1 kb downstream of the transcription start site of transcribed genes, and this localization requires both Pf1's and Mrg15's interaction with chromatin. Inactivation of this mammalian complex promotes increased RNAP II progression within transcribed regions and subsequent increased transcription. Our results define a novel mammalian complex that contributes to the regulation of transcription and point to divergent uses of the Sin3 protein homologues throughout evolution in the modulation of transcription. PMID:21041482

Intracranial inertial cavitation threshold and thermal ablation lesion creation using MRI-guided 220-kHz focused ultrasound surgery: preclinical investigation.

PubMed

Xu, Zhiyuan; Carlson, Carissa; Snell, John; Eames, Matt; Hananel, Arik; Lopes, M Beatriz; Raghavan, Prashant; Lee, Cheng-Chia; Yen, Chun-Po; Schlesinger, David; Kassell, Neal F; Aubry, Jean-Francois; Sheehan, Jason

2015-01-01

In biological tissues, it is known that the creation of gas bubbles (cavitation) during ultrasound exposure is more likely to occur at lower rather than higher frequencies. Upon collapsing, such bubbles can induce hemorrhage. Thus, acoustic inertial cavitation secondary to a 220-kHz MRI-guided focused ultrasound (MRgFUS) surgery is a serious safety issue, and animal studies are mandatory for laying the groundwork for the use of low-frequency systems in future clinical trials. The authors investigate here the in vivo potential thresholds of MRgFUS-induced inertial cavitation and MRgFUS-induced thermal coagulation using MRI, acoustic spectroscopy, and histology. Ten female piglets that had undergone a craniectomy were sonicated using a 220-kHz transcranial MRgFUS system over an acoustic energy range of 5600-14,000 J. For each piglet, a long-duration sonication (40-second duration) was performed on the right thalamus, and a short sonication (20-second duration) was performed on the left thalamus. An acoustic power range of 140-300 W was used for long-duration sonications and 300-700 W for short-duration sonications. Signals collected by 2 passive cavitation detectors were stored in memory during each sonication, and any subsequent cavitation activity was integrated within the bandwidth of the detectors. Real-time 2D MR thermometry was performed during the sonications. T1-weighted, T2-weighted, gradient-recalled echo, and diffusion-weighted imaging MRI was performed after treatment to assess the lesions. The piglets were killed immediately after the last series of posttreatment MR images were obtained. Their brains were harvested, and histological examinations were then performed to further evaluate the lesions. Two types of lesions were induced: thermal ablation lesions, as evidenced by an acute ischemic infarction on MRI and histology, and hemorrhagic lesions, associated with inertial cavitation. Passive cavitation signals exhibited 3 main patterns identified as follows: no cavitation, stable cavitation, and inertial cavitation. Low-power and longer sonications induced only thermal lesions, with a peak temperature threshold for lesioning of 53°C. Hemorrhagic lesions occurred only with high-power and shorter sonications. The sizes of the hemorrhages measured on macroscopic histological examinations correlated with the intensity of the cavitation activity (R2 = 0.74). The acoustic cavitation activity detected by the passive cavitation detectors exhibited a threshold of 0.09 V·Hz for the occurrence of hemorrhages. This work demonstrates that 220-kHz ultrasound is capable of inducing a thermal lesion in the brain of living swines without hemorrhage. Although the same acoustic energy can induce either a hemorrhage or a thermal lesion, it seems that low-power, long-duration sonication is less likely to cause hemorrhage and may be safer. Although further study is needed to decrease the likelihood of ischemic infarction associated with the 220-kHz ultrasound, the threshold established in this work may allow for the detection and prevention of deleterious cavitations.

Renal ablation using magnetic resonance-guided high intensity focused ultrasound: Magnetic resonance imaging and histopathology assessment.

PubMed

Saeed, Maythem; Krug, Roland; Do, Loi; Hetts, Steven W; Wilson, Mark W

2016-03-28

To use magnetic resonance-guided high intensity focused ultrasound (MRg-HIFU), magnetic resonance imaging (MRI) and histopathology for noninvasively ablating, quantifying and characterizing ablated renal tissue. Six anesthetized/mechanically-ventilated pigs underwent single/double renal sonication (n = 24) using a 3T-MRg-HIFU (1.1 MHz frequency and 3000J-4400J energies). T2-weighted fast spin echo (T2-W), perfusion saturation recovery gradient echo and contrast enhanced (CE) T1-weighted (T1-W) sequences were used for treatment planning, temperature monitoring, lesion visualization, characterization and quantification, respectively. Histopathology was conducted in excised kidneys to quantify and characterize cellular and vascular changes. Paired Student's t-test was used and a P-value < 0.05 was considered statistically significant. Ablated renal parenchyma could not be differentiated from normal parenchyma on T2-W or non-CE T1-W sequences. Ablated renal lesions were visible as hypoenhanced regions on perfusion and CE T1-W MRI sequences, suggesting perfusion deficits and necrosis. Volumes of ablated parenchyma on CE T1-W images in vivo (0.12-0.36 cm(3) for single sonication 3000J, 0.50-0.84 cm(3), for double 3000J, 0.75-0.78 cm(3) for single 4400J and 0.12-2.65 cm(3) for double 4400J) and at postmortem (0.23-0.52 cm(3), 0.25-0.82 cm(3), 0.45-0.68 cm(3) and 0.29-1.80 cm(3), respectively) were comparable. The ablated volumes on 3000J and 4400J double sonication were significantly larger than single (P < 0.01), thus, the volume and depth of ablated tissue depends on the applied energy and number of sonication. Macroscopic and microscopic examinations confirmed the locations and presence of coagulation necrosis, vascular damage and interstitial hemorrhage, respectively. Contrast enhanced MRI provides assessment of MRg-HIFU renal ablation. Histopathology demonstrated coagulation necrosis, vascular damage and confirmed the volume of damage seen on MRI.

Preclinical evaluation of a low-frequency transcranial MRI-guided focused ultrasound system in a primate model

NASA Astrophysics Data System (ADS)

McDannold, Nathan; Livingstone, Margaret; Barış Top, Can; Sutton, Jonathan; Todd, Nick; Vykhodtseva, Natalia

2016-11-01

This study investigated thermal ablation and skull-induced heating with a 230 kHz transcranial MRI-guided focused ultrasound (TcMRgFUS) system in nonhuman primates. We evaluated real-time acoustic feedback and aimed to understand whether cavitation contributed to the heating and the lesion formation. In four macaques, we sonicated thalamic targets at acoustic powers of 34-560 W (896-7590 J). Tissue effects evaluated with MRI and histology were compared to MRI-based temperature and thermal dose measurements, acoustic emissions recorded during the experiments, and acoustic and thermal simulations. Peak temperatures ranged from 46 to 57 °C, and lesions were produced in 5/8 sonicated targets. A linear relationship was observed between the applied acoustic energy and both the focal and brain surface heating. Thermal dose thresholds were 15-50 cumulative equivalent minutes at 43 °C, similar to prior studies at higher frequencies. Histology was also consistent with earlier studies of thermal effects in the brain. The system successfully controlled the power level and maintained a low level of cavitation activity. Increased acoustic emissions observed in 3/4 animals occurred when the focal temperature rise exceeded approximately 16 °C. Thresholds for thermally-significant subharmonic and wideband emissions were 129 and 140 W, respectively, corresponding to estimated pressure amplitudes of 2.1 and 2.2 MPa. Simulated focal heating was consistent with the measurements for sonications without thermally-significant acoustic emissions; otherwise it was consistently lower than the measurements. Overall, these results suggest that the lesions were produced by thermal mechanisms. The detected acoustic emissions, however, and their association with heating suggest that cavitation might have contributed to the focal heating. Compared to earlier work with a 670 kHz TcMRgFUS system, the brain surface heating was substantially reduced and the focal heating was higher with this 230 kHz system, suggesting that a reduced frequency can increase the treatment envelope for TcMRgFUS and potentially reduce the risk of skull heating.

The antimicrobial peptide derived from insulin-like growth factor-binding protein 5, AMP-IBP5, regulates keratinocyte functions through Mas-related gene X receptors.

PubMed

Chieosilapatham, Panjit; Niyonsaba, François; Kiatsurayanon, Chanisa; Okumura, Ko; Ikeda, Shigaku; Ogawa, Hideoki

2017-10-01

In addition to their microbicidal properties, host defense peptides (HDPs) display various immunomodulatory functions, including keratinocyte production of cytokines/chemokines, proliferation, migration and wound healing. Recently, a novel HDP named AMP-IBP5 (antimicrobial peptide derived from insulin-like growth factor-binding protein 5) was shown to exhibit antimicrobial activity against numerous pathogens, even at concentrations comparable to those of human β-defensins and LL-37. However, the immunomodulatory role of AMP-IBP5 in cutaneous tissue remains unknown. To investigate whether AMP-IBP5 triggers keratinocyte activation and to clarify its mechanism. Production of cytokines/chemokines and growth factors was determined by appropriate ELISA kits. Cell migration was assessed by in vitro wound closure assay, whereas cell proliferation was analyzed using BrdU incorporation assay complimented with XTT assay. MAPK and NF-κB activation was determined by Western blotting. Intracellular cAMP levels were assessed using cAMP enzyme immunoassay kit. Among various cytokines/chemokines and growth factors tested, AMP-IBP5 selectively increased the production of IL-8 and VEGF. Moreover, AMP-IBP5 markedly enhanced keratinocyte migration and proliferation. AMP-IBP5-induced keratinocyte activation was mediated by Mrg X1-X4 receptors with MAPK and NF-κB pathways working downstream, as evidenced by the inhibitory effects of MrgX1-X4 siRNAs and ERK-, JNK-, p38- and NF-κB-specific inhibitors. We confirmed that AMP-IBP5 indeed induced MAPK and NF-κB activation. Furthermore, AMP-IBP5-induced VEGF but not IL-8 production correlated with an increase in intracellular cAMP. Our findings suggest that in addition to its antimicrobial function, AMP-IBP5 might contribute to wound healing process through activation of keratinocytes. Copyright © 2017 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Focused ultrasound delivery of Raman nanoparticles across the blood-brain barrier: potential for targeting experimental brain tumors.

PubMed

Diaz, Roberto Jose; McVeigh, Patrick Z; O'Reilly, Meaghan A; Burrell, Kelly; Bebenek, Matthew; Smith, Christian; Etame, Arnold B; Zadeh, Gelareh; Hynynen, Kullervo; Wilson, Brian C; Rutka, James T

2014-07-01

Spectral mapping of nanoparticles with surface enhanced Raman scattering (SERS) capability in the near-infrared range is an emerging molecular imaging technique. We used magnetic resonance image-guided transcranial focused ultrasound (TcMRgFUS) to reversibly disrupt the blood-brain barrier (BBB) adjacent to brain tumor margins in rats. Glioma cells were found to internalize SERS capable nanoparticles of 50nm or 120nm physical diameter. Surface coating with anti-epidermal growth factor receptor antibody or non-specific human immunoglobulin G, resulted in enhanced cell uptake of nanoparticles in-vitro compared to nanoparticles with methyl terminated 12-unit polyethylene glycol surface. BBB disruption permitted the delivery of SERS capable spherical 50 or 120nm gold nanoparticles to the tumor margins. Thus, nanoparticles with SERS imaging capability can be delivered across the BBB non-invasively using TcMRgFUS and have the potential to be used as optical tracking agents at the invasive front of malignant brain tumors. This study demonstrates the use of magnetic resonance image-guided transcranial focused ultrasound to open the BBB and enable spectral mapping of nanoparticles with surface enhanced Raman scattering (SERS)-based molecular imaging for experimental tumor tracking. Copyright © 2014 Elsevier Inc. All rights reserved.

Phase aberration simulation study of MRgFUS breast treatments

PubMed Central

Farrer, Alexis I.; Almquist, Scott; Dillon, Christopher R.; Neumayer, Leigh A.; Parker, Dennis L.; Christensen, Douglas A.; Payne, Allison

2016-01-01

Purpose: This simulation study evaluates the effects of phase aberration in breast MR-guided focused ultrasound (MRgFUS) ablation treatments performed with a phased-array transducer positioned laterally to the breast. A quantification of these effects in terms of thermal dose delivery and the potential benefits of phase correction is demonstrated in four heterogeneous breast numerical models. Methods: To evaluate the effects of varying breast tissue properties on the quality of the focus, four female volunteers with confirmed benign fibroadenomas were imaged using 3T MRI. These images were segmented into numerical models with six tissue types, with each tissue type assigned standard acoustic properties from the literature. Simulations for a single-plane 16-point raster-scan treatment trajectory centered in a fibroadenoma in each modeled breast were performed for a breast-specific MRgFUS system. At each of the 16 points, pressure patterns both with and without applying a phase correction technique were determined with the hybrid-angular spectrum method. Corrected phase patterns were obtained using a simulation-based phase aberration correction technique to adjust each element’s transmit phase to obtain maximized constructive interference at the desired focus. Thermal simulations were performed for both the corrected and uncorrected pressure patterns using a finite-difference implementation of the Pennes bioheat equation. The effect of phase correction was evaluated through comparison of thermal dose accumulation both within and outside a defined treatment volume. Treatment results using corrected and uncorrected phase aberration simulations were compared by evaluating the power required to achieve a 20 °C temperature rise at the first treatment location. The extent of the volumes that received a minimum thermal dose of 240 CEM at 43 °C inside the intended treatment volume as well as the volume in the remaining breast tissues was also evaluated in the form of a dose volume ratio (DVR), a DVR percent change between corrected and uncorrected phases, and an additional metric that measured phase spread. Results: With phase aberration correction applied, there was an improvement in the focus for all breast anatomies as quantified by a reduction in power required (13%–102%) to reach 20 °C when compared to uncorrected simulations. Also, the DVR percent change increased by 5%–77% in seven out of eight cases, indicating an improvement to the treatment as measured by a reduction in thermal dose deposited to the nontreatment tissues. Breast compositions with a higher degree of heterogeneity along the ultrasound beam path showed greater reductions in thermal dose delivered outside of the treatment volume with correction applied than beam trajectories that propagated through more homogeneous breast compositions. An increasing linear trend was observed between the DVR percent change and the phase-spread metric (R2 = 0.68). Conclusions: These results indicate that performing phase aberration correction for breast MRgFUS treatments is beneficial for the small-aperture transducer (14.4 × 9.8 cm) evaluated in this work. While all breast anatomies could benefit from phase aberration correction, greater benefits are observed in more heterogeneous anatomies. PMID:26936722

Jobs and Economic Development Impact (JEDI) Model: Offshore Wind User Reference Guide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lantz, E.; Goldberg, M.; Keyser, D.

2013-06-01

The Offshore Wind Jobs and Economic Development Impact (JEDI) model, developed by NREL and MRG & Associates, is a spreadsheet based input-output tool. JEDI is meant to be a user friendly and transparent tool to estimate potential economic impacts supported by the development and operation of offshore wind projects. This guide describes how to use the model as well as technical information such as methodology, limitations, and data sources.

A prospective trial of magnetic resonance-guided focused ultrasound thalamotomy for essential tremor: Results at the 2-year follow-up.

PubMed

Chang, Jin Woo; Park, Chang Kyu; Lipsman, Nir; Schwartz, Michael L; Ghanouni, Pejman; Henderson, Jaimie M; Gwinn, Ryder; Witt, Jennifer; Tierney, Travis S; Cosgrove, G Rees; Shah, Binit B; Abe, Keiichi; Taira, Takaomi; Lozano, Andres M; Eisenberg, Howard M; Fishman, Paul S; Elias, W Jeffrey

2018-01-01

Magnetic resonance guided focused ultrasound (MRgFUS) has recently been investigated as a new treatment modality for essential tremor (ET), but the durability of the procedure has not yet been evaluated. This study reports results at a 2- year follow-up after MRgFUS thalamotomy for ET. A total of 76 patients with moderate-to-severe ET, who had not responded to at least two trials of medical therapy, were enrolled in the original randomized study of unilateral thalamotomy and evaluated using the clinical rating scale for tremor. Sixty-seven of the patients continued in the open-label extension phase of the study with monitoring for 2 years. Nine patients were excluded by 2 years, for example, because of alternative therapy such as deep brain stimulation (n = 3) or inadequate thermal lesioning (n = 1). However, all patients in each follow-up period were analyzed. Mean hand tremor score at baseline (19.8 ± 4.9; 76 patients) improved by 55% at 6 months (8.6 ± 4.5; 75 patients). The improvement in tremor score from baseline was durable at 1 year (53%; 8.9 ± 4.8; 70 patients) and at 2 years (56%; 8.8 ± 5.0; 67 patients). Similarly, the disability score at baseline (16.4 ± 4.5; 76 patients) improved by 64% at 6 months (5.4 ± 4.7; 75 patients). This improvement was also sustained at 1 year (5.4 ± 5.3; 70 patients) and at 2 years (6.5 ± 5.0; 67 patients). Paresthesias and gait disturbances were the most common adverse effects at 1 year-each observed in 10 patients with an additional 5 patients experiencing neurological adverse effects. None of the adverse events worsened over the period of follow-up, and 2 of these resolved. There were no new delayed complications at 2 years. Tremor suppression after MRgFUS thalamotomy for ET is stably maintained at 2 years. Latent or delayed complications do not develop after treatment. Ann Neurol 2018;83:107-114. © 2017 American Neurological Association.

An experimental model to investigate the targeting accuracy of MR-guided focused ultrasound ablation in liver.

PubMed

Petrusca, Lorena; Viallon, Magalie; Breguet, Romain; Terraz, Sylvain; Manasseh, Gibran; Auboiroux, Vincent; Goget, Thomas; Baboi, Loredana; Gross, Patrick; Sekins, K Michael; Becker, Christoph D; Salomir, Rares

2014-01-16

Magnetic Resonance-guided High Intensity Focused Ultrasound (MRgHIFU) is a hybrid technology that aims to offer non-invasive thermal ablation of targeted tumors or other pathological tissues. Acoustic aberrations and non-linear wave propagating effects may shift the focal point significantly away from the prescribed (or, theoretical) position. It is therefore mandatory to evaluate the spatial accuracy of ablation for a given HIFU protocol and/or device. We describe here a method for producing a user-defined ballistic target as an absolute reference marker for MRgHIFU ablations. The investigated method is based on trapping a mixture of MR contrast agent and histology stain using radiofrequency (RF) ablation causing cell death and coagulation. A dedicated RF-electrode was used for the marker fixation as follows: a RF coagulation (4 W, 15 seconds) and injection of the mixture followed by a second RF coagulation. As a result, the contrast agent/stain is encapsulated in the intercellular space. Ultrasonography imaging was performed during the procedure, while high resolution T1w 3D VIBE MR acquisition was used right after to identify the position of the ballistic marker and hence the target tissue. For some cases, after the marker fixation procedure, HIFU volumetric ablations were produced by a phased-array HIFU platform. First ex vivo experiments were followed by in vivo investigation on four rabbits in thigh muscle and six pigs in liver, with follow-up at Day 7. At the end of the procedure, no ultrasound indication of the marker's presence could be observed, while it was clearly visible under MR and could be conveniently used to prescribe the HIFU ablation, centered on the so-created target. The marker was identified at Day 7 after treatment, immediately after animal sacrifice, after 3 weeks of post-mortem formalin fixation and during histology analysis. Its size ranged between 2.5 and 4 mm. Experimental validation of this new ballistic marker method was performed for liver MRgHIFU ablation, free of any side effects (e.g. no edema around the marker, no infection, no bleeding). The study suggests that the absolute reference marker had ultrasound conspicuity below the detection threshold, was irreversible, MR-compatible and MR-detectable, while also being a well-established histology staining technique.

An experimental model to investigate the targeting accuracy of MR-guided focused ultrasound ablation in liver

PubMed Central

2014-01-01

Background Magnetic Resonance-guided High Intensity Focused Ultrasound (MRgHIFU) is a hybrid technology that aims to offer non-invasive thermal ablation of targeted tumors or other pathological tissues. Acoustic aberrations and non-linear wave propagating effects may shift the focal point significantly away from the prescribed (or, theoretical) position. It is therefore mandatory to evaluate the spatial accuracy of ablation for a given HIFU protocol and/or device. We describe here a method for producing a user-defined ballistic target as an absolute reference marker for MRgHIFU ablations. Methods The investigated method is based on trapping a mixture of MR contrast agent and histology stain using radiofrequency (RF) ablation causing cell death and coagulation. A dedicated RF-electrode was used for the marker fixation as follows: a RF coagulation (4 W, 15 seconds) and injection of the mixture followed by a second RF coagulation. As a result, the contrast agent/stain is encapsulated in the intercellular space. Ultrasonography imaging was performed during the procedure, while high resolution T1w 3D VIBE MR acquisition was used right after to identify the position of the ballistic marker and hence the target tissue. For some cases, after the marker fixation procedure, HIFU volumetric ablations were produced by a phased-array HIFU platform. First ex vivo experiments were followed by in vivo investigation on four rabbits in thigh muscle and six pigs in liver, with follow-up at Day 7. Results At the end of the procedure, no ultrasound indication of the marker’s presence could be observed, while it was clearly visible under MR and could be conveniently used to prescribe the HIFU ablation, centered on the so-created target. The marker was identified at Day 7 after treatment, immediately after animal sacrifice, after 3 weeks of post-mortem formalin fixation and during histology analysis. Its size ranged between 2.5 and 4 mm. Conclusions Experimental validation of this new ballistic marker method was performed for liver MRgHIFU ablation, free of any side effects (e.g. no edema around the marker, no infection, no bleeding). The study suggests that the absolute reference marker had ultrasound conspicuity below the detection threshold, was irreversible, MR-compatible and MR-detectable, while also being a well-established histology staining technique. PMID:24433332

Methodology on quantification of sonication duration for safe application of MR guided focused ultrasound for liver tumour ablation.

PubMed

Mihcin, Senay; Karakitsios, Ioannis; Le, Nhan; Strehlow, Jan; Demedts, Daniel; Schwenke, Michael; Haase, Sabrina; Preusser, Tobias; Melzer, Andreas

2017-12-01

Magnetic Resonance Guided Focused Ultrasound (MRgFUS) for liver tumour ablation is a challenging task due to motion caused by breathing and occlusion due the ribcage between the transducer and the tumour. To overcome these challenges, a novel system for liver tumour ablation during free breathing has been designed. The novel TRANS-FUSIMO Treatment System (TTS, EUFP7) interacts with a Magnetic Resonance (MR) scanner and a focused ultrasound transducer to sonicate to a moving target in liver. To meet the requirements of ISO 13485; a quality management system for medical device design, the system needs to be tested for certain process parameters. The duration of sonication and, the delay after the sonication button is activated, are among the parameters that need to be quantified for efficient and safe ablation of tumour tissue. A novel methodology is developed to quantify these process parameters. A computerised scope is programmed in LabVIEW to collect data via hydrophone; where the coordinates of fiber-optic sensor assembly was fed into the TRANS-FUSIMO treatment software via Magnetic Resonance Imaging (MRI) to sonicate to the tip of the sensor, which is synchronised with the clock of the scope, embedded in a degassed water tank via sensor assembly holder. The sonications were executed for 50 W, 100 W, 150 W for 10 s to quantify the actual sonication duration and the delay after the emergency stop by two independent operators for thirty times. The deviation of the system from the predefined specs was calculated. Student's-T test was used to investigate the user dependency. The duration of sonication and the delay after the sonication were quantified successfully with the developed method. TTS can sonicate with a maximum deviation of 0.16 s (Std 0.32) from the planned duration and with a delay of 14 ms (Std 0.14) for the emergency stop. Student's T tests indicate that the results do not depend on operators (p > .05). The evidence obtained via this protocol is crucial for translation- of-research into the clinics for safe application of MRgFUS. The developed protocol could be used for system maintenance in compliance with quality systems in clinics for daily quality assurance routines. Copyright © 2017 Elsevier B.V. All rights reserved.

MR-Guided Pulsed High-Intensity Focused Ultrasound Enhancement of Gene Therapy Combined With Androgen Deprivation and Radiotherapy for Prostate Cancer Treatment

DTIC Science & Technology

2009-09-01

first statement of work is to determine if high intensity focused ultrasound ( HIFU ) increases the cellular uptake of AS-MDM2, AS-bcl-2 and AS-PKA...Drug Delivery in Prostate Tumor in vivo Using MR Guided Focused Ultrasound (MRg HIFU ). WC, IFMBE Proceedings 25: pp341-344, 2009 6...pharmaceutical agents in the treatment target. In the model system proposed, pulsed high intensity focused ultrasound ( HIFU ) is hypothesized to improve

Laser induced thermal therapy (LITT) for pediatric brain tumors: case-based review

PubMed Central

Riordan, Margaret

2014-01-01

Integration of Laser induced thermal therapy (LITT) to magnetic resonance imaging (MRI) have created new options for treating surgically challenging tumors in locations that would otherwise have represented an intrinsic comorbidity by the approach itself. As new applications and variations of the use are discussed, we present a case-based review of the history, development, and subsequent updates of minimally invasive MRI-guided laser interstitial thermal therapy (MRgLITT) ablation in pediatric brain tumors. PMID:26835340

Cost Prediction via Quantitative Analysis of Complexity in U.S. Navy Shipbuilding

DTIC Science & Technology

2014-06-01

in regards to the analysis of advanced sensors and weaponry, the summation of singular values via a singular value decomposition will be used in the...In the DDG 51 class, the Main Reduction Gear (MRG) reduces the 3600-RPM produced by the LM-2500 gas turbines to approximately 168-RPM (at full...RDT&E efforts are currently underway to reduce complexity of the MCS by developing a wireless approach that will concurrently boost the host ship’s

MR Guided Pulsed High Intensity Focused Ultrasound Enhancement of Gene Therapy Combined with Androgen Deprivation and Radiotherapy for Prostate Cancer Treatment

DTIC Science & Technology

2012-09-01

for the treatment of prostate tumor-bearing mice using a clinical MRgHIFU device. We performed animal studies for quantitative measurement of the...by measuring the protein expression level of MDM2, p53 and p21 using immunohistochemical staining and west blotting techniques. We also performed...therapy) in implanted prostate tumors in mice in vivo by measuring the protein expression level of MDM, p53 and p21 with time points after treatment

Focal point determination in magnetic resonance-guided focused ultrasound using tracking coils.

PubMed

Svedin, Bryant T; Beck, Michael J; Hadley, J Rock; Merrill, Robb; de Bever, Joshua T; Bolster, Bradley D; Payne, Allison; Parker, Dennis L

2017-06-01

To develop a method for rapid prediction of the geometric focus location in MR coordinates of a focused ultrasound (US) transducer with arbitrary position and orientation without sonicating. Three small tracker coil circuits were designed, constructed, attached to the transducer housing of a breast-specific MR-guided focused US (MRgFUS) system with 5 degrees of freedom, and connected to receiver channel inputs of an MRI scanner. A one-dimensional sequence applied in three orthogonal directions determined the position of each tracker, which was then corrected for gradient nonlinearity. In a calibration step, low-level heating located the US focus in one transducer position orientation where the tracker positions were also known. Subsequent US focus locations were determined from the isometric transformation of the trackers. The accuracy of this method was verified by comparing the tracking coil predictions to thermal center of mass calculated using MR thermometry data acquired at 16 different transducer positions for MRgFUS sonications in a homogeneous gelatin phantom. The tracker coil predicted focus was an average distance of 2.1 ± 1.1 mm from the thermal center of mass. The one-dimensional locator sequence and prediction calculations took less than 1 s to perform. This technique accurately predicts the geometric focus for a transducer with arbitrary position and orientation without sonicating. Magn Reson Med 77:2424-2430, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Pitfalls of Ovarian Ablative Magnetic Resonance-guided Radiation Therapy for Refractory Endometriosis

PubMed Central

Tetar, Shyama; Bohoudi, Omar; Nieboer, Theodoor; Lagerwaard, Frank

2018-01-01

In this case presentation, we describe the challenges of performing magnetic resonance-guided radiation therapy (MRgRT) with plan adaptation in a patient with advanced endometriosis, in whom several prior therapeutic attempts were unsuccessful and extensive pelvic irradiation was regarded as being too toxic. Treatment was delivered in two sessions, first for the seemingly only active right ovary, and at a later stage for the left ovary. Some logistical problems were encountered during the preparation of the first treatment, which were subsequently optimized for the second treatment by using transvaginal ultrasound to determine the optimum time point for simulation and delivery. Using breath-hold gated delivery and plan adaptation, radiation dose to the bowel could be minimized, resulting in good tolerance of treatment. Because of the need to simulate and deliver in a brief optimal time span for visibility of the follicles in the ovaries, a single fraction dose of 8 Gy was used in our patient. Hormonal outcome after her second treatment is still pending. In conclusion, MRgRT with plan adaptation is feasible for the occasional patient with refractory endometriosis. Simulation and delivery needs to be synchronized with the menstrual cycle, ensuring that the Graafian follicles allow the ovaries to be visible on magnetic resonance imaging (MRI). Because the ovaries are only visible on T2-weighted MRI for a very brief period of time, we suggest that it is preferable to use single fraction radiotherapy with a brief interval between simulation imaging and delivery. PMID:29750135

Adaptive model-predictive controller for magnetic resonance guided focused ultrasound therapy.

PubMed

de Bever, Joshua; Todd, Nick; Payne, Allison; Christensen, Douglas A; Roemer, Robert B

2014-11-01

Minimising treatment time and protecting healthy tissues are conflicting goals that play major roles in making magnetic resonance image-guided focused ultrasound (MRgFUS) therapies clinically practical. We have developed and tested in vivo an adaptive model-predictive controller (AMPC) that reduces treatment time, ensures safety and efficacy, and provides flexibility in treatment set-up. The controller realises time savings by modelling the heated treatment cell's future temperatures and thermal dose accumulation in order to anticipate the optimal time to switch to the next cell. Selected tissues are safeguarded by a configurable temperature constraint. Simulations quantified the time savings realised by each controller feature as well as the trade-offs between competing safety and treatment time parameters. In vivo experiments in rabbit thighs established the controller's effectiveness and reliability. In all in vivo experiments the target thermal dose of at least 240 CEM43 was delivered everywhere in the treatment volume. The controller's temperature safety limit reliably activated and constrained all protected tissues to <9 CEM43. Simulations demonstrated the path independence of the controller, and that a path which successively proceeds to the hottest untreated neighbouring cell leads to significant time savings, e.g. when compared to a concentric spiral path. Use of the AMPC produced a compounding time-saving effect; reducing the treatment cells' heating times concurrently reduced heating of normal tissues, which eliminated cooling periods. Adaptive model-predictive control can automatically deliver safe, effective MRgFUS treatments while significantly reducing treatment times.

A Real-Time Data Acquisition and Processing Framework Based on FlexRIO FPGA and ITER Fast Plant System Controller

NASA Astrophysics Data System (ADS)

Yang, C.; Zheng, W.; Zhang, M.; Yuan, T.; Zhuang, G.; Pan, Y.

2016-06-01

Measurement and control of the plasma in real-time are critical for advanced Tokamak operation. It requires high speed real-time data acquisition and processing. ITER has designed the Fast Plant System Controllers (FPSC) for these purposes. At J-TEXT Tokamak, a real-time data acquisition and processing framework has been designed and implemented using standard ITER FPSC technologies. The main hardware components of this framework are an Industrial Personal Computer (IPC) with a real-time system and FlexRIO devices based on FPGA. With FlexRIO devices, data can be processed by FPGA in real-time before they are passed to the CPU. The software elements are based on a real-time framework which runs under Red Hat Enterprise Linux MRG-R and uses Experimental Physics and Industrial Control System (EPICS) for monitoring and configuring. That makes the framework accord with ITER FPSC standard technology. With this framework, any kind of data acquisition and processing FlexRIO FPGA program can be configured with a FPSC. An application using the framework has been implemented for the polarimeter-interferometer diagnostic system on J-TEXT. The application is able to extract phase-shift information from the intermediate frequency signal produced by the polarimeter-interferometer diagnostic system and calculate plasma density profile in real-time. Different algorithms implementations on the FlexRIO FPGA are compared in the paper.

Photolysis of Caged Ca2+ But Not Receptor-Mediated Ca2+ Signaling Triggers Astrocytic Glutamate Release

PubMed Central

Smith, Nathan A.; Xu, Qiwu; Goldman, Siri; Peng, Weiguo; Huang, Jason H.; Takano, Takahiro; Nedergaard, Maiken

2013-01-01

Astrocytes in hippocampal slices can dynamically regulate synaptic transmission in a process mediated by increases in intracellular Ca2+. However, it is debated whether astrocytic Ca2+ signals result in release of glutamate. We here compared astrocytic Ca2+ signaling triggered by agonist exposure versus photolysis side by side. Using transgenic mice in which astrocytes selectively express the MrgA1 receptor, we found that receptor-mediated astrocytic Ca2+ signaling consistently triggered neuronal hyperpolarization and decreased the frequency of miniature excitatory postsynaptic currents (EPSCs). In contrast, photolysis of caged Ca2+ (o-nitrophenyl–EGTA) in astrocytes led to neuronal depolarization and increased the frequency of mEPSCs through a metabotropic glutamate receptor-mediated pathway. Analysis of transgenic mice in which astrocytic vesicular release is suppressed (dominant-negative SNARE mice) and pharmacological manipulations suggested that glutamate is primarily released by opening of anion channels rather than exocytosis. Combined, these studies show that photolysis but not by agonists induced astrocytic Ca2+ signaling triggers glutamate release. PMID:24174673

Seasonal variability of convectively coupled equatorial waves (CCEWs) in recent high-top CMIP5 models

NASA Astrophysics Data System (ADS)

Zakaria, Dzaki; Lubis, Sandro W.; Setiawan, Sonni

2018-05-01

Tropical weather system is controlled by periodic atmospheric disturbances ranging from daily to subseasonal time scales. One of the most prominent atmospheric disturbances in the tropics is convectively coupled equatorial waves (CCEWs). CCEWs are excited by latent heating due to a large-scale convective system and have a significant influence on weather system. They include atmospheric equatorial Kelvin wave, Mixed Rossby Gravity (MRG) wave, Equatorial Rossby (ER) wave and Tropical Depression (TD-type) wave. In this study, we will evaluate the seasonal variability of CCEWs activity in nine high-top CMIP5 models, including their spatial distribution in the troposphere. Our results indicate that seasonal variability of Kelvin waves is well represented in MPI-ESM-LR and MPI-ESM-MR, with maximum activity occurring during boreal spring. The seasonal variability of MRG waves is well represented in CanESM2, HadGEM2-CC, IPSL-CM5A-LR and IPSL-CM5A-MR, with maximum activity observed during boreal summer. On the other hand, ER waves are well captured by IPSL-CM5A-LR and IPSL-CM5A-MR and maximize during boreal fall; while TD-type waves, with maximum activity observed during boreal summer, are well observed in CanESM2, HadGEM2-CC, IPSL-CM5A-LR and IPSL-CM5A-MR. Our results indicate that the skill of CMIP5 models in representing seasonal variability of CCEWs highly depends on the convective parameterization and the spatial or vertical resolution used by each model.

Quantification of intraventricular blood clot in MR-guided focused ultrasound surgery

NASA Astrophysics Data System (ADS)

Hess, Maggie; Looi, Thomas; Lasso, Andras; Fichtinger, Gabor; Drake, James

2015-03-01

Intraventricular hemorrhage (IVH) affects nearly 15% of preterm infants. It can lead to ventricular dilation and cognitive impairment. To ablate IVH clots, MR-guided focused ultrasound surgery (MRgFUS) is investigated. This procedure requires accurate, fast and consistent quantification of ventricle and clot volumes. We developed a semi-autonomous segmentation (SAS) algorithm for measuring changes in the ventricle and clot volumes. Images are normalized, and then ventricle and clot masks are registered to the images. Voxels of the registered masks and voxels obtained by thresholding the normalized images are used as seed points for competitive region growing, which provides the final segmentation. The user selects the areas of interest for correspondence after thresholding and these selections are the final seeds for region growing. SAS was evaluated on an IVH porcine model. SAS was compared to ground truth manual segmentation (MS) for accuracy, efficiency, and consistency. Accuracy was determined by comparing clot and ventricle volumes produced by SAS and MS, and comparing contours by calculating 95% Hausdorff distances between the two labels. In Two-One-Sided Test, SAS and MS were found to be significantly equivalent (p < 0.01). SAS on average was found to be 15 times faster than MS (p < 0.01). Consistency was determined by repeated segmentation of the same image by both SAS and manual methods, SAS being significantly more consistent than MS (p < 0.05). SAS is a viable method to quantify the IVH clot and the lateral brain ventricles and it is serving in a large-scale porcine study of MRgFUS treatment of IVH clot lysis.

Ionization chamber correction factors for MR-linacs

NASA Astrophysics Data System (ADS)

Pojtinger, Stefan; Steffen Dohm, Oliver; Kapsch, Ralf-Peter; Thorwarth, Daniela

2018-06-01

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B. The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0–2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

Ionization chamber correction factors for MR-linacs.

PubMed

Pojtinger, Stefan; Dohm, Oliver Steffen; Kapsch, Ralf-Peter; Thorwarth, Daniela

2018-06-07

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B . The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0-2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

TU-G-210-03: Acoustic Simulations in Transcranial MRgFUS: Treatment Prediction and Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vyas, U.

Modeling can play a vital role in predicting, optimizing and analyzing the results of therapeutic ultrasound treatments. Simulating the propagating acoustic beam in various targeted regions of the body allows for the prediction of the resulting power deposition and temperature profiles. In this session we will apply various modeling approaches to breast, abdominal organ and brain treatments. Of particular interest is the effectiveness of procedures for correcting for phase aberrations caused by intervening irregular tissues, such as the skull in transcranial applications or inhomogeneous breast tissues. Also described are methods to compensate for motion in targeted abdominal organs such asmore » the liver or kidney. Douglas Christensen – Modeling for Breast and Brain HIFU Treatment Planning Tobias Preusser – TRANS-FUSIMO - An Integrative Approach to Model-Based Treatment Planning of Liver FUS Urvi Vyas – Acoustic Simulations in Transcranial MRgFUS: Treatment Prediction and Analysis Learning Objectives: Understand the role of acoustic beam modeling for predicting the effectiveness of therapeutic ultrasound treatments. Apply acoustic modeling to specific breast, liver, kidney and transcranial anatomies. Determine how to obtain appropriate acoustic modeling parameters from clinical images. Understand the separate role of absorption and scattering in energy delivery to tissues. See how organ motion can be compensated for in ultrasound therapies. Compare simulated data with clinical temperature measurements in transcranial applications. Supported by NIH R01 HL172787 and R01 EB013433 (DC); EU Seventh Framework Programme (FP7/2007-2013) under 270186 (FUSIMO) and 611889 (TRANS-FUSIMO)(TP); and P01 CA159992, GE, FUSF and InSightec (UV)« less

Combined Inter- and Intrafractional Plan Adaptation Using Fraction Partitioning in Magnetic Resonance-guided Radiotherapy Delivery.

PubMed

Lagerwaard, Frank; Bohoudi, Omar; Tetar, Shyama; Admiraal, Marjan A; Rosario, Tezontl S; Bruynzeel, Anna

2018-04-05

Magnetic resonance-guided radiation therapy (MRgRT) not only allows for superior soft-tissue setup and online MR-guidance during delivery but also for inter-fractional plan re-optimization or adaptation. This plan adaptation involves repeat MR imaging, organs at risk (OARs) re-contouring, plan prediction (i.e., recalculating the baseline plan on the anatomy of that moment), plan re-optimization, and plan quality assurance. In contrast, intrafractional plan adaptation cannot be simply performed by pausing delivery at any given moment, adjusting contours, and re-optimization because of the complex and composite nature of deformable dose accumulation. To overcome this limitation, we applied a practical workaround by partitioning treatment fractions, each with half the original fraction dose. In between successive deliveries, the patient remained in the treatment position and all steps of the initial plan adaptation were repeated. Thus, this second re-optimization served as an intrafractional plan adaptation at 50% of the total delivery. The practical feasibility of this partitioning approach was evaluated in a patient treated with MRgRT for locally advanced pancreatic cancer (LAPC). MRgRT was delivered in 40Gy in 10 fractions, with two fractions scheduled successively on each treatment day. The contoured gross tumor volume (GTV) was expanded by 3 mm, excluding parts of the OARs within this expansion to derive the planning target volume for daily re-optimization (PTV OPT ). The baseline GTVV 95%  achieved in this patient was 80.0% to adhere to the high-dose constraints for the duodenum, stomach, and bowel (V 33 Gy <1 cc and V 36 Gy <0.1 cc). Treatment was performed on the MRIdian (ViewRay Inc, Mountain View, USA) using video-assisted breath-hold in shallow inspiration. The dual plan adaptation resulted, for each partitioned fraction, in the generation of Plan PREDICTED1 , Plan RE-OPTIMIZED1  (inter-fractional adaptation), Plan PREDICTED2 , and Plan RE-OPTIMIZED2  (intrafractional adaptation). An offline analysis was performed to evaluate the benefit of inter-fractional versus intrafractional plan adaptation with respect to GTV coverage and high-dose OARs sparing for all five partitioned fractions. Interfractional changes in adjacent OARs were substantially larger than intrafractional changes. Mean GTV V 95% was 76.8 ± 1.8% (Plan PREDICTED1 ), 83.4 ± 5.7% (Plan RE-OPTIMIZED1 ), 82.5 ± 4.3% (Plan PREDICTED2 ),and 84.4 ± 4.4% (Plan RE-OPTIMIZED2 ). Both plan re-optimizations appeared important for correcting the inappropriately high duodenal V 33 Gy values of 3.6 cc (Plan PREDICTED1 ) and 3.9 cc (Plan PREDICTED2 ) to 0.2 cc for both re-optimizations. To a smaller extent, this improvement was also observed for V 25 Gy values. For the stomach, bowel, and all other OARs, high and intermediate doses were well below preset constraints, even without re-optimization. The mean delivery time of each daily treatment was 90 minutes. This study presents the clinical application of combined inter-fractional and intrafractional plan adaptation during MRgRT for LAPC using fraction partitioning with successive re-optimization. Whereas, in this study, interfractional plan adaptation appeared to benefit both GTV coverage and OARs sparing, intrafractional adaptation was particularly useful for high-dose OARs sparing. Although all necessary steps lead to a prolonged treatment duration, this may be applied in selected cases where high doses to adjacent OARs are regarded as critical.

Combined Inter- and Intrafractional Plan Adaptation Using Fraction Partitioning in Magnetic Resonance-guided Radiotherapy Delivery

PubMed Central

Bohoudi, Omar; Tetar, Shyama; Admiraal, Marjan A; Rosario, Tezontl S; Bruynzeel, Anna

2018-01-01

Magnetic resonance-guided radiation therapy (MRgRT) not only allows for superior soft-tissue setup and online MR-guidance during delivery but also for inter-fractional plan re-optimization or adaptation. This plan adaptation involves repeat MR imaging, organs at risk (OARs) re-contouring, plan prediction (i.e., recalculating the baseline plan on the anatomy of that moment), plan re-optimization, and plan quality assurance. In contrast, intrafractional plan adaptation cannot be simply performed by pausing delivery at any given moment, adjusting contours, and re-optimization because of the complex and composite nature of deformable dose accumulation. To overcome this limitation, we applied a practical workaround by partitioning treatment fractions, each with half the original fraction dose. In between successive deliveries, the patient remained in the treatment position and all steps of the initial plan adaptation were repeated. Thus, this second re-optimization served as an intrafractional plan adaptation at 50% of the total delivery. The practical feasibility of this partitioning approach was evaluated in a patient treated with MRgRT for locally advanced pancreatic cancer (LAPC). MRgRT was delivered in 40Gy in 10 fractions, with two fractions scheduled successively on each treatment day. The contoured gross tumor volume (GTV) was expanded by 3 mm, excluding parts of the OARs within this expansion to derive the planning target volume for daily re-optimization (PTVOPT). The baseline GTVV95% achieved in this patient was 80.0% to adhere to the high-dose constraints for the duodenum, stomach, and bowel (V33 Gy <1 cc and V36 Gy <0.1 cc). Treatment was performed on the MRIdian (ViewRay Inc, Mountain View, USA) using video-assisted breath-hold in shallow inspiration. The dual plan adaptation resulted, for each partitioned fraction, in the generation of PlanPREDICTED1, PlanRE-OPTIMIZED1 (inter-fractional adaptation), PlanPREDICTED2, and PlanRE-OPTIMIZED2 (intrafractional adaptation). An offline analysis was performed to evaluate the benefit of inter-fractional versus intrafractional plan adaptation with respect to GTV coverage and high-dose OARs sparing for all five partitioned fractions. Interfractional changes in adjacent OARs were substantially larger than intrafractional changes. Mean GTV V95% was 76.8 ± 1.8% (PlanPREDICTED1), 83.4 ± 5.7% (PlanRE-OPTIMIZED1), 82.5 ± 4.3% (PlanPREDICTED2),and 84.4 ± 4.4% (PlanRE-OPTIMIZED2). Both plan re-optimizations appeared important for correcting the inappropriately high duodenal V33 Gy values of 3.6 cc (PlanPREDICTED1) and 3.9 cc (PlanPREDICTED2) to 0.2 cc for both re-optimizations. To a smaller extent, this improvement was also observed for V25 Gy values. For the stomach, bowel, and all other OARs, high and intermediate doses were well below preset constraints, even without re-optimization. The mean delivery time of each daily treatment was 90 minutes. This study presents the clinical application of combined inter-fractional and intrafractional plan adaptation during MRgRT for LAPC using fraction partitioning with successive re-optimization. Whereas, in this study, interfractional plan adaptation appeared to benefit both GTV coverage and OARs sparing, intrafractional adaptation was particularly useful for high-dose OARs sparing. Although all necessary steps lead to a prolonged treatment duration, this may be applied in selected cases where high doses to adjacent OARs are regarded as critical. PMID:29876156

Magnetic resonance-guided shielding of prefocal acoustic obstacles in focused ultrasound therapy: application to intercostal ablation in liver.

PubMed

Salomir, Rares; Petrusca, Lorena; Auboiroux, Vincent; Muller, Arnaud; Vargas, Maria-Isabel; Morel, Denis R; Goget, Thomas; Breguet, Romain; Terraz, Sylvain; Hopple, Jerry; Montet, Xavier; Becker, Christoph D; Viallon, Magalie

2013-06-01

The treatment of liver cancer is a major public health issue because the liver is a frequent site for both primary and secondary tumors. Rib heating represents a major obstacle for the application of extracorporeal focused ultrasound to liver ablation. Magnetic resonance (MR)-guided external shielding of acoustic obstacles (eg, the ribs) was investigated here to avoid unwanted prefocal energy deposition in the pathway of the focused ultrasound beam. Ex vivo and in vivo (7 female sheep) experiments were performed in this study. Magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) was performed using a randomized 256-element phased-array transducer (f∼1 MHz) and a 3-T whole-body clinical MR scanner. A physical mask was inserted in the prefocal beam pathway, external to the body, to block the energy normally targeted on the ribs. The effectiveness of the reflecting material was investigated by characterizing the efficacy of high-intensity focused ultrasound beam reflection and scattering on its surface using Schlieren interferometry. Before high-intensity focused ultrasound sonication, the alignment of the protectors with the conical projections of the ribs was required and achieved in multiple steps using the embedded graphical tools of the MR scanner. Multiplanar near real-time MR thermometry (proton resonance frequency shift method) enabled the simultaneous visualization of the local temperature increase at the focal point and around the exposed ribs. The beam defocusing due to the shielding was evaluated from the MR acoustic radiation force impulse imaging data. Both MR thermometry (performed with hard absorber positioned behind a full-aperture blocking shield) and Schlieren interferometry indicated a very good energy barrier of the shielding material. The specific temperature contrast between rib surface (spatial average) and focus, calculated at the end point of the MRgHIFU sonication, with protectors vs no protectors, indicated an important reduction of the temperature elevation at the ribs' surface, typically by 3.3 ± 0.4 in vivo. This was translated into an exponential reduction in thermal dose by several orders of magnitude. The external shielding covering the full conical shadow of the ribs was more effective when the protectors could be placed close to the ribs' surface and had a tendency to lose its efficiency when placed further from the ribs. Hepatic parenchyma was safely ablated in vivo using this rib-sparing strategy and single-focus independent sonications. A readily available, MR-compatible, effective, and cost-competitive method for rib protection in transcostal MRgHIFU was validated in this study, using specific reflective strips. The current approach permitted safe intercostal ablation of small volumes (0.7 mL) of liver parenchyma.

An overview of the CILBO spectral observation program

NASA Astrophysics Data System (ADS)

Rudawska, R.; Zender, J.; Koschny, D.

2016-01-01

The video equipment can be easily adopted with a spectral grating to obtain spectral information from meteors. Therefore, in recent years spectroscopic observations of meteors have become quite popular. The Meteor Research Group (MRG) of the European Space Agency has been working on upgrating the analysis of meteor spectra as well, operating image-intensified camera with objective grating (ICC8). ICC8 is located on Tenerife station of the double-station camera setup CILBO (Canary Island Long-Baseline Observatory). The pipeline software processes data with the standard calibration procedure (dark current, flat field, lens distortion corrections). While using the position of a meteor recorded by ICC7 camera (zero order), the position of the 1st order spectrum as a function of wavelength is computed Moreover, thanks to the double meteor observations carried by ICC7 (Tenerife) and ICC9 (La Palma), trajectory of a meteor and its orbit is determined. Which merged with simultaneously measurement of meteor spectrum from ICC8, allow us to identify the source of the meteoroid. Here, we report on preliminary results from a sample of meteor spectra collected by CILBO-ICC8 camera since 2012.

Poster - Thur Eve - 05: Safety systems and failure modes and effects analysis for a magnetic resonance image guided radiation therapy system.

PubMed

Lamey, M; Carlone, M; Alasti, H; Bissonnette, J P; Borg, J; Breen, S; Coolens, C; Heaton, R; Islam, M; van Proojen, M; Sharpe, M; Stanescu, T; Jaffray, D

2012-07-01

An online Magnetic Resonance guided Radiation Therapy (MRgRT) system is under development. The system is comprised of an MRI with the capability of travel between and into HDR brachytherapy and external beam radiation therapy vaults. The system will provide on-line MR images immediately prior to radiation therapy. The MR images will be registered to a planning image and used for image guidance. With the intention of system safety we have performed a failure modes and effects analysis. A process tree of the facility function was developed. Using the process tree as well as an initial design of the facility as guidelines possible failure modes were identified, for each of these failure modes root causes were identified. For each possible failure the assignment of severity, detectability and occurrence scores was performed. Finally suggestions were developed to reduce the possibility of an event. The process tree consists of nine main inputs and each of these main inputs consisted of 5 - 10 sub inputs and tertiary inputs were also defined. The process tree ensures that the overall safety of the system has been considered. Several possible failure modes were identified and were relevant to the design, construction, commissioning and operating phases of the facility. The utility of the analysis can be seen in that it has spawned projects prior to installation and has lead to suggestions in the design of the facility. © 2012 American Association of Physicists in Medicine.

Toxicological responses of Laeonereis acuta (Polychaeta, Nereididae) after acute, subchronic and chronic exposure to cadmium.

PubMed

Dolagaratz Carricavur, Arantxa; Chiodi Boudet, Leila; Romero, María Belén; Polizzi, Paula; Marcovecchio, Jorge Eduardo; Gerpe, Marcela

2018-03-01

The objective of this study was to analyze the toxicological responses of the estuarine polychaete Laeonereis acuta after acute (96h), subchronic (7 days) and chronic (14 days) exposure to cadmium (Cd). Concentrations of metallothioneins (MT), lipid peroxidation (LPO), total Cd and metal-rich granules (MRG) were evaluated. Seasonal variations of MT and LPO levels in the wild were also measured. Polychaetes were obtained in the Quequén estuary located southeast of Buenos Aires Province, Argentina. For the acute toxicity assay, individuals were exposed to 10; 30, 65; 310; 600; 1300; 2000; 4300; 8100; 16300µgCdL -1 , which included levels of environmental relevance and median lethal concentrations (LC 50 ) for related species of polychaete. Based on 96h LC 50 values, polychaetes were exposed to sublethal doses of Cd. The concentrations for both subchronic and chronic assays were: 10; 30; 65; 310; 600; 1300; 2000; 4300µgCdL -1 . The 96h LC 50 value was 8234.9µgL -1 , which was within the values reported for other species of polychaete, indicating a high tolerance to Cd. MT induction was not observed for any time exposure. In additoin, LPO levels showed no differences with respect to control levels, which indicated an absence of oxidative damage caused by Cd. However, the total Cd and MRG-Cd concentrations in L. acuta in all tested treatments showed significant differences with respect to control levels. L. acuta were able to accumulate Cd in their tissues in the form of granules which are the main mechanism of Cd detoxification. Copyright © 2017 Elsevier Inc. All rights reserved.

The role of the glycosyl moiety of myricetin derivatives in anti-HIV-1 activity in vitro.

PubMed

Ortega, Joseph T; Suárez, Alirica I; Serrano, Maria L; Baptista, Jani; Pujol, Flor H; Rangel, Hector R

2017-10-12

Plant extracts are sources of valuable compounds with biological activity, especially for the anti-proliferative activity against pathogens or tumor cells. Myricetin is a flavonoid found in several plants that has been described as an inhibitor of Human immunodeficiency virus type 1 (HIV-1) through its action against the HIV reverse transcriptase, but myricetin derivatives have not been fully studied. The aim of this study was to evaluate the anti-HIV-1 activity of glycosylated metabolites obtained from Marcetia taxifolia and derived from myricetin: myricetin rhamnoside and myricetin 3-(6-rhamnosylgalactoside). Compounds were obtained from organic extracts by maceration of aerial parts of M. taxifolia. All biological assays were performed in the MT4 cell line. Antiviral activity was measured as inhibition of p24 and reverse transcriptase with a fluorescent assay. Both flavonoids have antiviral activity in vitro, with an EC50 of 120 µM for myricetin 3-rhamnoside (MR) and 45 µM for myricetin 3-(6-rhamnosylgalactoside) (MRG), both significantly lower than the EC50 of myricetin (230 µM). Although both compounds inhibited the reverse transcriptase activity, with an IC50 of 10.6 µM for MR and 13.8 µM for MRG, myricetin was the most potent, with an IC50 of 7.6 µM, and an inhibition greater than 80%. Molecular docking approach showed correlation between the free energy of binding with the assays of enzyme inhibition. The results suggest that glycosylated moiety might enhance the anti-HIV-1 activity of myricetin, probably by favoring the internalization of the flavonoid into the cell. The inhibition of the HIV-1 reverse transcriptase is likely responsible for the antiviral activity.

Towards real-time thermometry using simultaneous multislice MRI

NASA Astrophysics Data System (ADS)

Borman, P. T. S.; Bos, C.; de Boorder, T.; Raaymakers, B. W.; Moonen, C. T. W.; Crijns, S. P. M.

2016-09-01

MR-guided thermal therapies, such as high-intensity focused ultrasound (MRgHIFU) and laser-induced thermal therapy (MRgLITT) are increasingly being applied in oncology and neurology. MRI is used for guidance since it can measure temperature noninvasively based on the proton resonance frequency shift (PRFS). For therapy guidance using PRFS thermometry, high temporal resolution and large spatial coverage are desirable. We propose to use the parallel imaging technique simultaneous multislice (SMS) in combination with controlled aliasing (CAIPIRINHA) to accelerate the acquisition. We compare this with the sensitivity encoding (SENSE) acceleration technique. Two experiments were performed to validate that SMS can be used to increase the spatial coverage or the temporal resolution. The first was performed in agar gel using LITT heating and a gradient-echo sequence with echo-planar imaging (EPI), and the second was performed in bovine muscle using HIFU heating and a gradient-echo sequence without EPI. In both experiments temperature curves from an unaccelerated scan and from SMS, SENSE, and SENSE/SMS accelerated scans were compared. The precision was quantified by a standard deviation analysis of scans without heating. Both experiments showed a good agreement between the temperature curves obtained from the unaccelerated, and SMS accelerated scans, confirming that accuracy was maintained during SMS acceleration. The standard deviations of the temperature measurements obtained with SMS were significantly smaller than when SENSE was used, implying that SMS allows for higher acceleration. In the LITT and HIFU experiments SMS factors up to 4 and 3 were reached, respectively, with a loss of precision of less than a factor of 3. Based on these results we conclude that SMS acceleration of PRFS thermometry is a valuable addition to SENSE, because it allows for a higher temporal resolution or bigger spatial coverage, with a higher precision.

Differential tolerance of two Gammarus pulex populations transplanted from different metallogenic regions to a polymetal gradient.

PubMed

Khan, Farhan R; Irving, Jennifer R; Bury, Nicolas R; Hogstrand, Christer

2011-03-01

The River Hayle, Cornwall, UK exhibits pronounced Cu and Zn concentration gradients which were used to compare the metal handling abilities of two populations of Gammarus pulex (Crustacea: Amphipoda). One population was native to the Hayle region (Drym) and presumably has been historically impacted by elevated Cu and Zn levels, whilst naïve gammarids were collected from the River Cray, Kent, UK. Both populations were subject to a 32 day in situ exposure at four R. Hayle sites (Drym, Godolphin, Relubbus and St. Erth). Mortality (LT50), Cu and Zn accumulation and sub-cellular distribution, and oxidative stress (malondialdehyde production) increased with the expected Cu and Zn bioavailabilities at the four sites (i.e. Godolphin>Relubbus>St. Erth>Drym). The naïve population experienced greater metal induced effects in terms of Cu and Zn accumulation, oxidative stress responses and lower LT50s. Analysis of Cu and Zn sub-cellular distribution, however, revealed no significant differences in metal handling. In both populations each metal was localised predominantly to the sub-cellular fraction containing metal bound to metallothionein-like proteins (MTLP) or that holding both metal-rich granules (MRG) and exoskeleton, MTLP and MRG binding being indicative of metal detoxification. However, a greater capacity for detoxified metal storage is not a mechanism implicated in the perceived tolerance of the historically impacted gammarids. Instead our results suggest that the historically impacted population was adapted for lower uptake of Cu and Zn leading to lower bioaccumulation, stress response and ultimately mortality. These results demonstrate not only the usefulness of the in situ methodology, but also that differences in population exposure history can cause significant differences in metal responses during exposure at higher concentrations. Copyright © 2011 Elsevier B.V. All rights reserved.

Restoring Neurological Physiology: The Innovative Role of High-Energy MR-Guided Focused Ultrasound (HIMRgFUS). Preliminary Data from a New Method of Lesioning Surgery.

PubMed

Giugno, Antonella; Maugeri, Rosario; Graziano, Francesca; Gagliardo, Cesare; Franzini, Angelo; Catalano, Carlo; Midiri, Massimo; Iacopino, Domenico Gerardo

2017-01-01

Tremor is a disabling condition, common to several neurodegenerative diseases. Lesioning procedures and deep brain stimulation, respectively, of the ventralis intermedius nucleus for intentional tremor, and of the subthalamic nucleus for parkinsonian resting tremor, have been introduced in clinical practice for patients refractory to medical treatment. The combination of high-energy focused ultrasound (HIFUS) with sophisticated magnetic resonance (MR) instrumentation, together with accurate knowledge of the stereotactic brain coordinates, represents a revolution in neuromodulation. At the Neurosurgical Clinic and the Radiology Department of the University of Palermo,, two patients affected by severe and refractory forms of intentional tremor were treated by MRI-guided FUS (MRgFUS) with a unique 1.5 T MR scanner prototype that uses FUS. This apparatus is the only one of its type in the world." This is the first Italian experience, and the second in Europe, of treatment with MRI-gFUS for intentional tremor. But this is the very first experience in which a 1.5 T MRI apparatus was used. In both patients, the treatment completely abolished the tremor on the treated side, with results being excellent and stable after 7 and 5 months, respectively; no side effects were encountered. MRgFUS, recently introduced in clinical practice, and widely used at several clinical centers, has been shown to be a valid therapeutic alternative in the treatment of tremor in several neurodegenerative diseases. It is virtually safe, noninvasive, and very efficacious. We report this technique in which a 1.5 T MR scanner was used. Further investigations with long-term follow up and larger clinical series are needed.

Cadmium resistance in an oligochaete and its effect on cadmium trophic transfer to an omnivorous shrimp

USGS Publications Warehouse

Wallace, W.G.; Lopez, G.R.; Levinton, J.S.

1998-01-01

It has been demonstrated that the deposit-feeding oligochaete Limnodrilus hoffmeisteri inhabiting Foundry Cove (FC), a severely cadmium (Cd)-contaminated cove located on the Hudson River, New York, USA, has evolved resistance to Cd. In this study we investigate how this resistance influences Cd trophic transfer from this oligochaete to the grass shrimp Palaemonetes pugio. Cadmium-resistant worms collected from FC and nonresistant worms collected from an adjacent unpolluted site were investigated for differences in Cd tolerance, accumulation, subcellular distribution and bioavailability to shrimp. FC worms were more tolerant of Cd, surviving twice as long as worms from the unpolluted site during a toxicity bioassay. The 7 d concentration factor of Cd-resistant worms was 4 times greater than that of nonresistant worms (2020 vs 577). There were also differences between worm populations with respect to subcellular Cd distributions. Cd-resistant worms produced metallothionein-like proteins (MT) as well as metal-rich granules (MRG) for Cd storage and detoxification; nonresistant worms only produced MT. These differences in subcellular Cd distributions led to large differences in Cd bioavailability to shrimp; shrimp fed Cd-resistant worms absorbed 21% of the ingested Cd, while those fed nonresistant worms absorbed roughly 4 times that amount (~75%). These absorption efficiencies were in good agreement with the proportions of Cd bound to the worm's most biologically available subcellular fractions (i.e. the cytosol and organelles). Although Cd-resistant worms predominantly stored the toxic metal in biologically unavailable MRG, their increased accumulation of Cd would still result in substantial trophic transfer to shrimp because of the storage of Cd in the biologically available fractions. This work demonstrates that the evolution of Cd resistance can have profound implications for Cd bioavailability and cycling within aquatic ecosystems.

Improving Thermal Dose Accuracy in Magnetic Resonance-Guided Focused Ultrasound Surgery: Long-Term Thermometry Using a Prior Baseline as a Reference

PubMed Central

Bitton, Rachel R.; Webb, Taylor D.; Pauly, Kim Butts; Ghanouni, Pejman

2015-01-01

Purpose To investigate thermal dose volume (TDV) and non-perfused volume (NPV) of magnetic resonance-guided focused ultrasound (MRgFUS) treatments in patients with soft tissue tumors, and describe a method for MR thermal dosimetry using a baseline reference. Materials and Methods Agreement between TDV and immediate post treatment NPV was evaluated from MRgFUS treatments of five patients with biopsy-proven desmoid tumors. Thermometry data (gradient echo, 3T) were analyzed over the entire course of the treatments to discern temperature errors in the standard approach. The technique searches previously acquired baseline images for a match using 2D normalized cross-correlation and a weighted mean of phase difference images. Thermal dose maps and TDVs were recalculated using the matched baseline and compared to NPV. Results TDV and NPV showed between 47%–91% disagreement, using the standard immediate baseline method for calculating TDV. Long-term thermometry showed a nonlinear local temperature accrual, where peak additional temperature varied between 4–13°C (mean = 7.8°C) across patients. The prior baseline method could be implemented by finding a previously acquired matching baseline 61% ± 8% (mean ± SD) of the time. We found 7%–42% of the disagreement between TDV and NPV was due to errors in thermometry caused by heat accrual. For all patients, the prior baseline method increased the estimated treatment volume and reduced the discrepancies between TDV and NPV (P = 0.023). Conclusion This study presents a mismatch between in-treatment and post treatment efficacy measures. The prior baseline approach accounts for local heating and improves the accuracy of thermal dose-predicted volume. PMID:26119129

Improving thermal dose accuracy in magnetic resonance-guided focused ultrasound surgery: Long-term thermometry using a prior baseline as a reference.

PubMed

Bitton, Rachel R; Webb, Taylor D; Pauly, Kim Butts; Ghanouni, Pejman

2016-01-01

To investigate thermal dose volume (TDV) and non-perfused volume (NPV) of magnetic resonance-guided focused ultrasound (MRgFUS) treatments in patients with soft tissue tumors, and describe a method for MR thermal dosimetry using a baseline reference. Agreement between TDV and immediate post treatment NPV was evaluated from MRgFUS treatments of five patients with biopsy-proven desmoid tumors. Thermometry data (gradient echo, 3T) were analyzed over the entire course of the treatments to discern temperature errors in the standard approach. The technique searches previously acquired baseline images for a match using 2D normalized cross-correlation and a weighted mean of phase difference images. Thermal dose maps and TDVs were recalculated using the matched baseline and compared to NPV. TDV and NPV showed between 47%-91% disagreement, using the standard immediate baseline method for calculating TDV. Long-term thermometry showed a nonlinear local temperature accrual, where peak additional temperature varied between 4-13°C (mean = 7.8°C) across patients. The prior baseline method could be implemented by finding a previously acquired matching baseline 61% ± 8% (mean ± SD) of the time. We found 7%-42% of the disagreement between TDV and NPV was due to errors in thermometry caused by heat accrual. For all patients, the prior baseline method increased the estimated treatment volume and reduced the discrepancies between TDV and NPV (P = 0.023). This study presents a mismatch between in-treatment and post treatment efficacy measures. The prior baseline approach accounts for local heating and improves the accuracy of thermal dose-predicted volume. © 2015 Wiley Periodicals, Inc.

The dual regulation of substance P-mediated inflammation via human synovial mast cells in rheumatoid arthritis.

PubMed

Okamura, Yuki; Mishima, Shintaro; Kashiwakura, Jun-Ichi; Sasaki-Sakamoto, Tomomi; Toyoshima, Shota; Kuroda, Kazumichi; Saito, Shu; Tokuhashi, Yasuaki; Okayama, Yoshimichi

2017-09-01

Neural pathways are thought to be directly involved in the pathogenesis of rheumatoid arthritis (RA). Although synovial mast cells (MCs) are activated by substance P (SP), the role of MCs in neural pathways in RA remains unknown. The aims of this study were to investigate 1) whether tachykinins are produced by synovial MCs and whether production differs in RA and osteoarthritis (OA) patients, and 2) what is the responsible receptor for SP in synovial MCs. Synovial tissues were obtained from patients with RA or OA undergoing joint replacement surgery. Cultured synovium-derived MCs were generated by culturing dispersed synovial cells with stem cell factor. SP expression was investigated using immunofluorescence and enzyme immunoassays. Mas-related gene X2 (MrgX2) expression was reduced in human MCs using a lentiviral shRNA silencing technique. SP expression was localized around the cell membrane in 41% (median) of the MCs in synovium from RA but in only 7% of that from OA, suggesting the activation of MCs. Synovial MCs expressed tachykinin (TAC) 1 mRNA, the expression of which was upregulated by the aggregation of FcɛRI or the addition of aggregated IgG. However, the released SP appeared to be rapidly degraded by MC chymase. Synovial MCs were activated with SP through MrgX2 to release histamine without producing proinflammatory cytokines. Activated synovial MCs may rapidly degrade SP, which may downregulate the SP-mediated activation of synoviocytes in RA. On the other hand, SP activates MCs to induce inflammatory mediators, suggesting the dual regulation of SP-mediated inflammation by MCs in RA. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

Development, Characterization, and Implementation of a System for Focused Ultrasound-Mediated Blood-Brain Barrier Opening in Mice

NASA Astrophysics Data System (ADS)

Valdez, Michael Aaron

The blood-brain barrier BBB refers to the set of specialized endothelial cells that line the vasculature in the brain and effectively control movement of molecules into and out of the brain. While necessary for proper brain function, the BBB blocks 98% of drugs from entering the brain and is the most significant barrier to developing therapies for neurodegenerative diseases. Active transport allows some specific molecules to cross the BBB, but therapeutic development using this route has had limited success. A number of techniques have been used to bypass the BBB, but are often highly invasive and ineffective. Over the last two decades, a minimally invasive technique to transiently open the BBB has been under development that utilizes transcranial focused ultrasound (FUS) in combination with intravascular microbubble contrast agents. This method is often carried out in conjunction with magnetic resonance imaging (MRI) to guide and assess BBB opening and has been referred to as MRI guided FUS (MRgFUS). Because of the utility of mouse models of neurological disease and the exploratory nature of MRgFUS, systems that allow BBB opening in mice are a useful and necessary tool to develop and evaluate this method for clinical application. In this dissertation project, a custom built, cost-effective FUS system for opening the BBB in mice was developed, with the objective of using this device to deliver therapeutics to the brain. Being a custom device, it was necessary to evaluate the ultrasound output, verify in vivo safety, and anticipate the therapeutic effect. The scope of the work herein consists of the design, construction, and evaluation of system that fulfills these requirements. The final constructed system cost was an order of magnitude less than any commercially available MRgFUS system. At this low price point, the hardware could allow the implementation of the methodology in many more research areas than previously possible. Additionally, to anticipate the therapeutic effect, molecules of pharmacologically-relevant sizes were delivered to brain with a novel, multispectral approach. Results demonstrated that the device was able to safely open the BBB, and macromolecule delivery showed that both molecule size and FUS pressure both influence the amount and distribution of molecules in the brain. Using different ultrasound pressures, the threshold for BBB opening was found to be ≥ 180 kPa (0.13 MI). The threshold for damage was found to be ≥ 420 kPa (0.30 MI), and was minor at this pressure, but extensive for higher pressure (870 kPa, 0.62 MI), in which minor damage was caused by this pressure. Performing a novel implementation of a diffusion model on the fluorescence images of 500, 70, and 3 kDa dextran resulted in calculated diffusion coefficients of 0.032 +/- 0.015, 12 +/- 6.0, and 0.13 +/- 0.094 square microns per second, respectively.

Integrated ultrasound and magnetic resonance imaging for simultaneous temperature and cavitation monitoring during focused ultrasound therapies

PubMed Central

Arvanitis, Costas D.; McDannold, Nathan

2013-01-01

Purpose: Ultrasound can be used to noninvasively produce different bioeffects via viscous heating, acoustic cavitation, or their combination, and these effects can be exploited to develop a wide range of therapies for cancer and other disorders. In order to accurately localize and control these different effects, imaging methods are desired that can map both temperature changes and cavitation activity. To address these needs, the authors integrated an ultrasound imaging array into an MRI-guided focused ultrasound (MRgFUS) system to simultaneously visualize thermal and mechanical effects via passive acoustic mapping (PAM) and MR temperature imaging (MRTI), respectively. Methods: The system was tested with an MRgFUS system developed for transcranial sonication for brain tumor ablation in experiments with a tissue mimicking phantom and a phantom-filled ex vivo macaque skull. In experiments on cavitation-enhanced heating, 10 s continuous wave sonications were applied at increasing power levels (30–110 W) until broadband acoustic emissions (a signature for inertial cavitation) were evident. The presence or lack of signal in the PAM, as well as its magnitude and location, were compared to the focal heating in the MRTI. Additional experiments compared PAM with standard B-mode ultrasound imaging and tested the feasibility of the system to map cavitation activity produced during low-power (5 W) burst sonications in a channel filled with a microbubble ultrasound contrast agent. Results: When inertial cavitation was evident, localized activity was present in PAM and a marked increase in heating was observed in MRTI. The location of the cavitation activity and heating agreed on average after registration of the two imaging modalities; the distance between the maximum cavitation activity and focal heating was −3.4 ± 2.1 mm and −0.1 ± 3.3 mm in the axial and transverse ultrasound array directions, respectively. Distortions and other MRI issues introduced small uncertainties in the PAM/MRTI registration. Although there was substantial variation, a nonlinear relationship between the average intensity of the cavitation maps, which was relatively constant during sonication, and the peak temperature rise was evident. A fit to the data to an exponential had a correlation coefficient (R2) of 0.62. The system was also found to be capable of visualizing cavitation activity with B-mode imaging and of passively mapping cavitation activity transcranially during cavitation-enhanced heating and during low-power sonication with an ultrasound contrast agent. Conclusions: The authors have demonstrated the feasibility of integrating an ultrasound imaging array into an MRgFUS system to simultaneously map localized cavitation activity and temperature. The authors anticipate that this integrated approach can be utilized to develop controllers for cavitation-enhanced ablation and facilitate the optimization and development of this and other ultrasound therapies. The integrated system may also provide a useful tool to study the bioeffects of acoustic cavitation. PMID:24320468

Integrated ultrasound and magnetic resonance imaging for simultaneous temperature and cavitation monitoring during focused ultrasound therapies.

PubMed

Arvanitis, Costas D; McDannold, Nathan

2013-11-01

Ultrasound can be used to noninvasively produce different bioeffects via viscous heating, acoustic cavitation, or their combination, and these effects can be exploited to develop a wide range of therapies for cancer and other disorders. In order to accurately localize and control these different effects, imaging methods are desired that can map both temperature changes and cavitation activity. To address these needs, the authors integrated an ultrasound imaging array into an MRI-guided focused ultrasound (MRgFUS) system to simultaneously visualize thermal and mechanical effects via passive acoustic mapping (PAM) and MR temperature imaging (MRTI), respectively. The system was tested with an MRgFUS system developed for transcranial sonication for brain tumor ablation in experiments with a tissue mimicking phantom and a phantom-filled ex vivo macaque skull. In experiments on cavitation-enhanced heating, 10 s continuous wave sonications were applied at increasing power levels (30-110 W) until broadband acoustic emissions (a signature for inertial cavitation) were evident. The presence or lack of signal in the PAM, as well as its magnitude and location, were compared to the focal heating in the MRTI. Additional experiments compared PAM with standard B-mode ultrasound imaging and tested the feasibility of the system to map cavitation activity produced during low-power (5 W) burst sonications in a channel filled with a microbubble ultrasound contrast agent. When inertial cavitation was evident, localized activity was present in PAM and a marked increase in heating was observed in MRTI. The location of the cavitation activity and heating agreed on average after registration of the two imaging modalities; the distance between the maximum cavitation activity and focal heating was -3.4 ± 2.1 mm and -0.1 ± 3.3 mm in the axial and transverse ultrasound array directions, respectively. Distortions and other MRI issues introduced small uncertainties in the PAM∕MRTI registration. Although there was substantial variation, a nonlinear relationship between the average intensity of the cavitation maps, which was relatively constant during sonication, and the peak temperature rise was evident. A fit to the data to an exponential had a correlation coefficient (R(2)) of 0.62. The system was also found to be capable of visualizing cavitation activity with B-mode imaging and of passively mapping cavitation activity transcranially during cavitation-enhanced heating and during low-power sonication with an ultrasound contrast agent. The authors have demonstrated the feasibility of integrating an ultrasound imaging array into an MRgFUS system to simultaneously map localized cavitation activity and temperature. The authors anticipate that this integrated approach can be utilized to develop controllers for cavitation-enhanced ablation and facilitate the optimization and development of this and other ultrasound therapies. The integrated system may also provide a useful tool to study the bioeffects of acoustic cavitation.

Progress and plan of KSTAR plasma control system upgrade

DOE PAGES

Hahn, Sang-hee; Kim, Y. J.; Penaflor, B. G.; ...

2016-06-01

The plasma control system (PCS) has been one of essential systems in annual KSTAR plasma campaigns: starting from a single-process version in 2008, extensive upgrades are done through the previous 7 years in order to achieve major goals of KSTAR performance enhancement. Here, major implementations are explained in this paper. In consequences of successive upgrades, the present KSTAR PCS is able to achieve ~48 s of 500 kA plasma pulses with full real-time shaping controls and real-time NB power controls. It has become a huge system capable of dealing with 8 separate categories of algorithms, 26 actuators directly controllable duringmore » the shot, and real-time data communication units consisting of +180 analog channels and +600 digital input/outputs through the reflective memory (RFM) network. The next upgrade of the KSTAR PCS is planned in 2015 before the campaign. An overview of the upgrade layout will be given for this paper. The real-time system box is planned to use the CERN MRG-Realtime OS, an ITER-compatible standard operating system. New hardware is developed for faster real-time streaming system for future installations of actuators/diagnostics.« less

The assessment of serum-mediated phagocytosis of necrotic material by polymorphonuclear leukocytes to diagnose and predict the clinical features of systemic lupus erythematosus: an observational longitudinal study.

PubMed

Compagno, Michele; Gullstrand, Birgitta; Jacobsen, Søren; Eilertsen, Gro Ø; Nilsson, Jan Åke; Lood, Christian; Jönsen, Andreas; Truedsson, Lennart; Sturfelt, Gunnar; Bengtsson, Anders A

2016-02-10

Serum-mediated phagocytosis of antibody- and complement-opsonized necrotic cell material (NCM) by polymorphonuclear leukocytes can be quantified by using a flow cytometry-based assay. The phagocytosis of necrotic cell material (PNC) assay parallels the well-known lupus erythematosus cell test. In this study, we aimed to investigate the diagnostic accuracy of the assay and the relationship with clinical manifestations and disease activity in systemic lupus erythematosus (SLE). The diagnostic accuracy for SLE diagnosis of the PNC assay was studied by cross-sectional assessment of blood samples from 148 healthy control subjects and a multicenter rheumatic group (MRG) of 529 patients with different rheumatic symptoms. A cohort of 69 patients with an established SLE diagnosis (SLE cohort) underwent longitudinal clinical and laboratory follow-up for analysis of the temporal relationships between PNC positivity and specific clinical manifestations. In 35 of 529 MRG patients, 13 of whom had SLE, the PNC assay result was positive. Combined positivity of the PNC assay and anti-double-stranded DNA antibodies increased specificity and positive predictive value for SLE diagnosis to 0.99 and 0.67, respectively. In the longitudinal study, 42 of 69 SLE cohort patients had positive results in the PNC assay at least once. PNC assay positivity was associated with current hematological manifestations and could predict mucocutaneous manifestations. When combined with hypocomplementemia, PNC positivity preceded increased Systemic Lupus Erythematosus Disease Activity Index 2000 score, glomerulonephritis, and alopecia. Serum-mediated PNC by polymorphonuclear leukocytes is commonly but not exclusively seen in patients with SLE. The PNC assay may be used in follow-up of patients with SLE and, especially in combination with other routinely assessed laboratory tests, may help to predict flares and different clinical manifestations, including glomerulonephritis. Our results encourage further development of the PNC assay as a complementary laboratory tool in management of patients with SLE.

Improved rheological properties of dimorphic magnetorheological gels based on flower-like carbonyl iron particles

NASA Astrophysics Data System (ADS)

Yang, Pingan; Yu, Miao; Luo, Hongping; Fu, Jie; Qu, Hang; Xie, Yuanpeng

2017-09-01

In this study, a new kind of dimorphic magnetorheological gels (MRGs) based on the conventional carbonyl iron particles (CIPs) and flower-like CIPs have been prepared for improving the yield stress and dynamic mechanical properties. The flower-like CIPs are synthesized by a simple and facile in situ reduction method. Characterization results indicate that the flower-like CIPs are synthesized successfully and a layer of uniform and continuous Fe nanosheets are grown on the surface of the raw microsphere CIPs. In addition, the flower-like CIPs exhibit excellent magnetic properties, which the saturated mass magnetization (Ms) can achieve 168.76 emu/g. In order to study the influence of mass fraction of flower-like CIPs on the rheological properties of this dimorphic MRGs, a series of polyurethane-based dimorphic MRGs are prepared by partial substitution of the CIPs with as-synthesized flower-like CIPs, and the MR properties of them are systematically investigated under both oscillatory and rotational shear modes. The experimental results indicate that, with 8 wt% flower-like CIPs, the maximum dynamic yield stresses and magneto-induced shear yield stress of dimorphic MRGs are 58.11 kPa and 54.53 kPa, ∼1.39 and ∼1.37 times of the MRG without flower-like CIPs at the same magnetic particle content. Moreover, the average loss factor and the loss factor under 1 T of the sample (flower-like CIPs weight content 8 wt%) are 0.36 and 0.07, which are approximately 1.71 and 2.71 times than that in the non-substitution sample. The increased loss factor is beneficial to improving the vibration reduction effect of MRGs of damping devices in the whole magnetic field region. Furthermore, the possible mechanism for the enhanced MR properties in dimorphic MRGs is proposed. In summary, this work is expected to promote the design and application of MRG devices.

Osteoid osteoma: Magnetic resonance guided high intensity focused ultrasound for entirely non-invasive treatment. A prospective developmental study

NASA Astrophysics Data System (ADS)

Napoli, A.; de Soccio, V.; Cartocci, G.; Boni, F.; Anzidei, M.; Catalano, C.

2017-03-01

To determine the effect of acoustic energy delivered during MR guided Focused Ultrasound (MRgFUS) treatment of symptomatic osteoid osteomas. This prospective, IRB approved study involved 15 consecutive patients (11 m; 4f; mean age, 21) with clinical and imaging diagnosis of Osteoid Osteoma; all patients underwent MRgFUS ablation (ExAblate, InSightec; Discovery 750 MR unit, GE). Lesions located in the vertebral body were excluded, while lesions in proximity to joints or neurovascular bundles were included. Treatment success was determined at clinical and imaging follow-up at 1, 6 and 12 months post-treatment. A visual Analog Pain Score (VAS) was used to assess changes in symptoms. Bone changes at nidus site were evaluated on the basis of CT and dynamic ce-MR imaging (Gd-Bopta; Bracco) pre- and post-treatment. Treatment was carried out using a variable number of sonications (mean 4±1.8) with a mean energy deposition of 866±211 J. There were no treatment- or anesthesia-related complications. A statistically significant (p=0.001) difference was noted between the overall pre- and post-treatment mean VAS scores (8.3±1.6 and 0.6±1.5, respectively). Two treatments were conducted in patients with prior CTgRFA failure and needed two different session for achieving complete clinical successful. At imaging, edema and hyperemia associated with typical osteoid osteoma, gradually disappeared in all lesions. No apparent relationship between nidus vascular extinction and successful outcome was found. Variable reabsorption degree of sclerotic reaction was observed with nidus disappearance in 4 cases (27%). Treatment of osteoid osteoma using MR guided Focused Ultrasound can be performed safely with a high rate of success and without treatment related morbidity; our results indicated also a positive trend to bone rearrangement after treatment.

Quantitative Magnetic Resonance Thermometry and Its Use with MR-Guided Focused Ultrasound

NASA Astrophysics Data System (ADS)

Pauly, Kim

2014-03-01

Focused ultrasound (FUS) uses a large area array, typically outside the body, that is geometrically or electronically focused to a point deep in the body. Such focusing provides amplification of the ultrasound intensity, thereby allowing heating of tissue to the point of coagulation at the focus, without damage to the intervening tissue. Guidance of FUS treatments deep in the body can be done quantitatively with magnetic resonance (MR) thermometry, termed MRgFUS. The physics behind MR thermometry lie in the changes in hydrogen bonding with temperature. As tissue temperature rises, hydrogen bonds break, allowing the return of the electron cloud to shield water protons, reducing the magnetic field seen by the protons, and the resonant frequency. The change in resonant frequency is -0.01 ppm per degree C and is the same for all aqueous tissues. The result of the shift in proton resonant frequency is seen in the phase of gradient echo images. Subtraction of the phase of images acquired before and during heating allows the removal of background phase from other sources, yielding quantitative temperature maps. Temperature standard deviations less than 1 degree C are readily achievable and thermal dose maps are easily calculated. Thermal dose is found from a conversion of the whole temperature-time curve to an equivalent number of minutes at 43 degrees C. A thermal dose of 240 minutes is often taken as the threshold for tissue damage. MR thermometry is complicated by the motion of the target tissue and/or motion of other organs such as occurs during respiration. More sophisticated algorithms than the simple baseline subtraction take advantage of the facts that motion can be repetitive (in the case of respiratory motion) and/or the fact that the focal region in MRgFUS is small, allowing for extraction of the heat from the phase profile without subtraction of a background phase.

Minimizing eddy currents induced in the ground plane of a large phased-array ultrasound applicator for echo-planar imaging-based MR thermometry.

PubMed

Lechner-Greite, Silke M; Hehn, Nicolas; Werner, Beat; Zadicario, Eyal; Tarasek, Matthew; Yeo, Desmond

2016-01-01

The study aims to investigate different ground plane segmentation designs of an ultrasound transducer to reduce gradient field induced eddy currents and the associated geometric distortion and temperature map errors in echo-planar imaging (EPI)-based MR thermometry in transcranial magnetic resonance (MR)-guided focused ultrasound (tcMRgFUS). Six different ground plane segmentations were considered and the efficacy of each in suppressing eddy currents was investigated in silico and in operando. For the latter case, the segmented ground planes were implemented in a transducer mockup model for validation. Robust spoiled gradient (SPGR) echo sequences and multi-shot EPI sequences were acquired. For each sequence and pattern, geometric distortions were quantified in the magnitude images and expressed in millimeters. Phase images were used for extracting the temperature maps on the basis of the temperature-dependent proton resonance frequency shift phenomenon. The means, standard deviations, and signal-to-noise ratios (SNRs) were extracted and contrasted with the geometric distortions of all patterns. The geometric distortion analysis and temperature map evaluations showed that more than one pattern could be considered the best-performing transducer. In the sagittal plane, the star (d) (3.46 ± 2.33 mm) and star-ring patterns (f) (2.72 ± 2.8 mm) showed smaller geometric distortions than the currently available seven-segment sheet (c) (5.54 ± 4.21 mm) and were both comparable to the reference scenario (a) (2.77 ± 2.24 mm). Contrasting these results with the temperature maps revealed that (d) performs as well as (a) in SPGR and EPI. We demonstrated that segmenting the transducer ground plane into a star pattern reduces eddy currents to a level wherein multi-plane EPI for accurate MR thermometry in tcMRgFUS is feasible.

TH-AB-BRA-05: Lung Cannot Be Treated as Homogeneous in Radiation Transport Simulations in Magnetic Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malkov, V; Rogers, D; Jaffray, D

2016-06-15

Purpose: Magnetic fields in MRgRT are known to induce dose perturbations near lung-tissue interfaces. The goal of this study is to determine if the heterogeneous structure of the lung influences the dose distribution in a magnetic field. Method: The dose distribution from a 4 cm X 4 cm 6 MV photon beam in a 0, 0.6, or 1.5 T magnetic field in a homogeneous lung density (0.333 g/cm{sup 3}) geometry is compared to that in a heterogeneous segmented slab configuration. The heterogeneous phantom is composed of 2/3 water vapour and 1/3 liquid water such that the overall density of themore » lung regions in the two phantoms are equivalent. The EGSnrc DOSXYZnrc user code is used with a previously implemented magnetic field transport code. Results: For water vapour gap thickness of 2 mm, compared to the homogeneous lung case (which already exhibits significant dose perturbations in a magnetic field) differences as large as 12.3 ± 0.2 % are observed for a 0.6 T field and 9.3 ± 0.1 % for a 1.5 T field at the tissuelung interface, and on the order of several percent within the lung-like tissue region for both magnetic fields. Thicker gaps produced larger deviations while a gap thickness of 0.2 mm does not result in notable differences. Regardless of gap thickness, the heterogeneities had little effect on the 0 T simulations. Further, using smaller scoring regions revealed that dose averaging effects could obscure dose differences as large as 10 – 20 % within the heterogeneous structures of the lung-like media. Conclusions: This simple model demonstrates that media heterogeneities can play an important role in MRgRT dose distributions, and care must be taken in setting up any dose calculation in the lung in the presence of a magnetic field, especially for air regions larger than 2 mm.« less

WE-H-207B-00: MRgRT

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2016-06-15

In recent years, steady progress has been made towards the implementation of MRI in external beam radiation therapy for processes ranging from treatment simulation to in-room guidance. Novel procedures relying mostly on MR data are currently implemented in the clinic. This session will cover topics such as (a) commissioning and quality control of the MR in-room imagers and simulators specific to RT, (b) treatment planning requirements, constraints and challenges when dealing with various MR data, (c) quantification of organ motion with an emphasis on treatment delivery guidance, and (d) MR-driven strategies for adaptive RT workflows. The content of the sessionmore » was chosen to address both educational and practical key aspects of MR guidance. Learning Objectives: Good understanding of MR testing recommended for in-room MR imaging as well as image data validation for RT chain (e.g. image transfer, filtering for consistency, spatial accuracy, manipulation for task specific); Familiarity with MR-based planning procedures: motivation, core workflow requirements, current status, challenges; Overview of the current methods for the quantification of organ motion; Discussion on approaches for adaptive treatment planning and delivery. T. Stanescu - License agreement with Modus Medical Devices to develop a phantom for the quantification of MR image system-related distortions.; T. Stanescu, N/A.« less

Doctors as Stewards of medicare, or not: CAMSI, MRG, CDM, DRHC and the thin alphabet soup of physician support.

PubMed

Duffin, Jacalyn

2018-07-01

Physicians are deeply involved in Canadian medicare because it is through medicare that they are paid. However, from its origins to the present physicians -as a profession - have not been strong supporters of medicare. Fearing loss of income and individual autonomy, they have frequently opposed it with criticisms, strikes, threatened job action and lawsuits. Some opponents are unaware that medicare was a boon to physician income, and many fail to connect medicare with responsibility for improving the health status of the country. This paper will trace physician involvement, support and opposition to medicare from its inception to the present, with special attention to small physician organizations that have supported medicare. It will close with a proposal for how doctors could display greater stewardship.

Role of equatorial waves in tropical cyclogenesis

NASA Astrophysics Data System (ADS)

Schreck, Carl J., III

Tropical cyclones typically form within preexisting wavelike disturbances that couple with convection. Using Tropical Rainfall Measuring Mission (TRMM) multisatellite rainfall estimates, this study determines the relative number of tropical cyclones that can be attributed to various wave types, including the Madden--Julian oscillation (MJO), Kelvin waves, equatorial Rossby (ER) waves, mixed Rossby--gravity (MRG) waves, and tropical depression (TD)-type disturbances. Tropical cyclogenesis is attributed to an equatorial wave's convection when the filtered rainfall anomaly exceeds a threshold value at the genesis location. More storms are attributed to TD-type disturbances than to any other wave type in all of the Northern Hemisphere basins. In the Southern Hemisphere, however, ER waves and TD-type disturbances are equally important as precursors. Fewer storms are attributed to MRG waves, Kelvin waves, and the MJO in every basin. Although relatively few storms are attributed to the MJO, tropical cyclogenesis is 2.6 times more likely in its convective phase compared with its suppressed phase. This modulation arises in part because each equatorial wave type is amplified within MJO's convective phase. The amplification significantly increases the probability that these waves will act as tropical cyclone precursors. A case study from June 2002 illustrates the effects of a series of Kelvin waves on two tropical cyclone formations. These waves were embedded in the convective phase of the MJO. Together, the MJO and the Kelvin waves preconditioned the low-level environment for cyclogenesis. The first Kelvin wave weakened the trade easterlies, while the subsequent waves created monsoon westerlies near the equator. These westerlies provided the background cyclonic vorticity within which both storms developed. The effects of tropical cyclone-related rainfall anomalies are also investigated. In the wavenumber--frequency spectrum for rainfall, tropical cyclones can inflate the power for shorter wavelength westward propagating waves by up to 27%. This spectrum contains signals from all longitudes, but the greatest contamination occurs in regions like the Philippines where tropical cyclones are most frequent. Here, tropical cyclones contribute more than 40% of the rainfall variance in each filter band. To mitigate these effects, tropical cyclone-related anomalies were removed before filtering in this study.

Differences in Nutrient Sources Caused by Variations in Monsoon Strength and Land Use/Land Cover, Middle Rio Grande, NM

NASA Astrophysics Data System (ADS)

Oelsner, G. P.; Brooks, P. D.; Hogan, J. F.

2006-12-01

Synoptic sampling of the Middle Rio Grande (MRG) in central New Mexico was conducted each year during August from 2001 through 2006. Land use in the basin includes a large urban area around Albuquerque, agricultural areas, and rangeland. Because the Rio Grande is a highly managed river, the affects of land use and land cover on water quality are associated primarily with active management of river flows and water diversions and secondarily by episodic precipitation events that circumvent these management structures. A persistent monsoon regime brought heavy rains to the MRG in central New Mexico during July and August making 2006 the 8th wettest year on record for Albuquerque, NM. This summer's heavy rains increased river discharge and inputs from tributaries and ephemeral streams which served to reconnect the river to its floodplain and riparian area and transport solutes to the river from normally disconnected sources. Discharge in the Middle Rio Grande was 39 cms during the 2006 sampling event which is 250% higher than discharge during the previous sampling events. Under non-flood conditions, wastewater treatment plants (WWTP) are the primary source of nitrogen to the river. However, N loading from the Albuquerque WWTP was 40% lower in 2006 than previous years due to a decrease in effluent TDN concentrations. Tributaries had similar TDN concentrations in all years, but due to increased discharge, TDN loads from tributaries were an order of magnitude higher in 2006 and exceeded the TDN input from WWTPs. In all years, agricultural drains had lower TDN concentrations than the river water originally diverted for irrigation, suggesting that the agricultural areas function as a sink for nitrogen under a wide range of hydrologic conditions. Increased TDN concentrations and discharge rates resulted in a five-fold increase of N loading to Elephant Butte Reservoir from 1000 kgN/day to more than 5000 kgN/day. Analysis of DOC and stable isotopes of water should help to determine how hydrologic variability changes the relative role of different land uses and land covers as nutrient sources to the river.

A simulation technique for 3D MR-guided acoustic radiation force imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Payne, Allison, E-mail: apayne@ucair.med.utah.edu; Bever, Josh de; Farrer, Alexis

2015-02-15

Purpose: In magnetic resonance-guided focused ultrasound (MRgFUS) therapies, the in situ characterization of the focal spot location and quality is critical. MR acoustic radiation force imaging (MR-ARFI) is a technique that measures the tissue displacement caused by the radiation force exerted by the ultrasound beam. This work presents a new technique to model the displacements caused by the radiation force of an ultrasound beam in a homogeneous tissue model. Methods: When a steady-state point-source force acts internally in an infinite homogeneous medium, the displacement of the material in all directions is given by the Somigliana elastostatic tensor. The radiation forcemore » field, which is caused by absorption and reflection of the incident ultrasound intensity pattern, will be spatially distributed, and the tensor formulation takes the form of a convolution of a 3D Green’s function with the force field. The dynamic accumulation of MR phase during the ultrasound pulse can be theoretically accounted for through a time-of-arrival weighting of the Green’s function. This theoretical model was evaluated experimentally in gelatin phantoms of varied stiffness (125-, 175-, and 250-bloom). The acoustic and mechanical properties of the phantoms used as parameters of the model were measured using independent techniques. Displacements at focal depths of 30- and 45-mm in the phantoms were measured by a 3D spin echo MR-ARFI segmented-EPI sequence. Results: The simulated displacements agreed with the MR-ARFI measured displacements for all bloom values and focal depths with a normalized RMS difference of 0.055 (range 0.028–0.12). The displacement magnitude decreased and the displacement pattern broadened with increased bloom value for both focal depths, as predicted by the theory. Conclusions: A new technique that models the displacements caused by the radiation force of an ultrasound beam in a homogeneous tissue model theory has been rigorously validated through comparison with experimentally obtained 3D displacement data in homogeneous gelatin phantoms using a 3D MR-ARFI sequence. The agreement of the experimentally measured and simulated results demonstrates the potential to use MR-ARFI displacement data in MRgFUS therapies.« less

SU-E-J-03: Characterization of the Precision and Accuracy of a New, Preclinical, MRI-Guided Focused Ultrasound System for Image-Guided Interventions in Small-Bore, High-Field Magnets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ellens, N; Farahani, K

2015-06-15

Purpose: MRI-guided focused ultrasound (MRgFUS) has many potential and realized applications including controlled heating and localized drug delivery. The development of many of these applications requires extensive preclinical work, much of it in small animal models. The goal of this study is to characterize the spatial targeting accuracy and reproducibility of a preclinical high field MRgFUS system for thermal ablation and drug delivery applications. Methods: The RK300 (FUS Instruments, Toronto, Canada) is a motorized, 2-axis FUS positioning system suitable for small bore (72 mm), high-field MRI systems. The accuracy of the system was assessed in three ways. First, the precisionmore » of the system was assessed by sonicating regular grids of 5 mm squares on polystyrene plates and comparing the resulting focal dimples to the intended pattern, thereby assessing the reproducibility and precision of the motion control alone. Second, the targeting accuracy was assessed by imaging a polystyrene plate with randomly drilled holes and replicating the hole pattern by sonicating the observed hole locations on intact polystyrene plates and comparing the results. Third, the practicallyrealizable accuracy and precision were assessed by comparing the locations of transcranial, FUS-induced blood-brain-barrier disruption (BBBD) (observed through Gadolinium enhancement) to the intended targets in a retrospective analysis of animals sonicated for other experiments. Results: The evenly-spaced grids indicated that the precision was 0.11 +/− 0.05 mm. When image-guidance was included by targeting random locations, the accuracy was 0.5 +/− 0.2 mm. The effective accuracy in the four rodent brains assessed was 0.8 +/− 0.6 mm. In all cases, the error appeared normally distributed (p<0.05) in both orthogonal axes, though the left/right error was systematically greater than the superior/inferior error. Conclusions: The targeting accuracy of this device is sub-millimeter, suitable for many preclinical applications including focused drug delivery and thermal therapy. Funding support provided by Philips Healthcare.« less

The inability of Bacillus licheniformis perR mutant to grow is mainly due to the lack of PerR-mediated fur repression.

PubMed

Kim, Jung-Hoon; Yang, Yoon-Mo; Ji, Chang-Jun; Ryu, Su-Hyun; Won, Young-Bin; Ju, Shin-Yeong; Kwon, Yumi; Lee, Yeh-Eun; Youn, Hwan; Lee, Jin-Won

2017-06-01

PerR, a member of Fur family protein, is a metal-dependent H 2 O 2 sensing transcription factor that regulates genes involved in peroxide stress response. Industrially important bacterium Bacillus licheniformis contains three PerR-like proteins (PerR BL , PerR2, and PerR3) compared to its close relative Bacillus subtilis. Interestingly, unlike other bacteria including B. subtilis, no authentic perR BL null mutant could be established for B. licheniformis. Thus, we constructed a conditional perR BL mutant using a xylose-inducible promoter, and investigated the genes under the control of PerR BL . PerR BL regulon genes include katA, mrgA, ahpC, pfeT, hemA, fur, and perR as observed for PerR BS . However, there is some variation in the expression levels of fur and hemA genes between B. subtilis and B. licheniformis in the derepressed state. Furthermore, katA, mrgA, and ahpC are strongly induced, whereas the others are only weakly or not induced by H 2 O 2 treatment. In contrast to the B. subtilis perR null mutant which frequently gives rise to large colony phenotype mainly due to the loss of katA, the suppressors of B. licheniformis perR mutant, which can form colonies on LB agar, were all catalase-positive. Instead, many of the suppressors showed increased levels of siderophore production, suggesting that the suppressor mutation is linked to the fur gene. Consistent with this, perR fur double mutant could grow on LB agar without Fe supplementation, whereas perR katA double mutant could only grow on LB agar with Fe supplementation. Taken together, our data suggest that in B. licheniformis, despite the similarity in PerR BL and PerR BS regulon genes, perR is an essential gene required for growth and that the inability of perR null mutant to grow is mainly due to elevated expression of Fur.

A New Era of Image Guidance with Magnetic Resonance-guided Radiation Therapy for Abdominal and Thoracic Malignancies

PubMed Central

Paliwal, Bhudatt; Hill, Patrick; Bayouth, John E; Geurts, Mark W; Baschnagel, Andrew M; Bradley, Kristin A; Harari, Paul M; Rosenberg, Stephen; Brower, Jeffrey V; Wojcieszynski, Andrzej P; Hullett, Craig; Bayliss, R A; Labby, Zacariah E; Bassetti, Michael F

2018-01-01

Magnetic resonance-guided radiation therapy (MRgRT) offers advantages for image guidance for radiotherapy treatments as compared to conventional computed tomography (CT)-based modalities. The superior soft tissue contrast of magnetic resonance (MR) enables an improved visualization of the gross tumor and adjacent normal tissues in the treatment of abdominal and thoracic malignancies. Online adaptive capabilities, coupled with advanced motion management of real-time tracking of the tumor, directly allow for high-precision inter-/intrafraction localization. The primary aim of this case series is to describe MR-based interventions for localizing targets not well-visualized with conventional image-guided technologies. The abdominal and thoracic sites of the lung, kidney, liver, and gastric targets are described to illustrate the technological advancement of MR-guidance in radiotherapy. PMID:29872602

Treatment envelope evaluation in transcranial magnetic resonance-guided focused ultrasound utilizing 3D MR thermometry

PubMed Central

2014-01-01

Background Current clinical targets for transcranial magnetic resonance-guided focused ultrasound (tcMRgFUS) are all located close to the geometric center of the skull convexity, which minimizes challenges related to focusing the ultrasound through the skull bone. Non-central targets will have to be reached to treat a wider variety of neurological disorders and solid tumors. Treatment envelope studies utilizing two-dimensional (2D) magnetic resonance (MR) thermometry have previously been performed to determine the regions in which therapeutic levels of FUS can currently be delivered. Since 2D MR thermometry was used, very limited information about unintended heating in near-field tissue/bone interfaces could be deduced. Methods In this paper, we present a proof-of-concept treatment envelope study with three-dimensional (3D) MR thermometry monitoring of FUS heatings performed in a phantom and a lamb model. While the moderate-sized transducer used was not designed for transcranial geometries, the 3D temperature maps enable monitoring of the entire sonication field of view, including both the focal spot and near-field tissue/bone interfaces, for full characterization of all heating that may occur. 3D MR thermometry is achieved by a combination of k-space subsampling and a previously described temporally constrained reconstruction method. Results We present two different types of treatment envelopes. The first is based only on the focal spot heating—the type that can be derived from 2D MR thermometry. The second type is based on the relative near-field heating and is calculated as the ratio between the focal spot heating and the near-field heating. This utilizes the full 3D MR thermometry data achieved in this study. Conclusions It is shown that 3D MR thermometry can be used to improve the safety assessment in treatment envelope evaluations. Using a non-optimal transducer, it is shown that some regions where therapeutic levels of FUS can be delivered, as suggested by the first type of envelope, are not necessarily safely treated due to the amount of unintended near-field heating occurring. The results presented in this study highlight the need for 3D MR thermometry in tcMRgFUS. PMID:25343028

Focal therapy for localized unifocal and multifocal prostate cancer: A prospective development study using real time MR guided focused ultrasound

NASA Astrophysics Data System (ADS)

Napoli, A.; Caliolo, G.; Boni, F.; Anzidei, M.; Catalano, C.

2017-03-01

To assess safety and feasibility of non-invasive high intensity 3T MR guided focused ultrasound (MRgFUS) treatment of localized prostate cancer in an exploratory designed study. Men aged 45-80 years were eligible for this prospective study if they had low-risk localized prostate cancer (prostate specific antigen [PSA] ≤10 ng/mL, Gleason score ≤ 3 + 3), with no previous androgen deprivation or treatment for prostate cancer, and who could safely undergo multiparametric MRI (Discovery 750, GE; Gd-Bopta, Bracco) and have a spinal anesthetic. Patients underwent focal therapy using real time MR guided high intensity focused ultrasound (MRgFUS), delivered to all known cancer lesions, with a margin of normal tissue. Primary endpoints were adverse events (serious and otherwise) and urinary symptoms and erectile function assessed using patient questionnaires. 8 men were recruited between June 2011 and June 2012. After treatment, one man was admitted to hospital for acute urinary retention. Another patient had self-resolving, mild, intermittent dysuria (median duration 5.0 days). Urinary tract infection was not reported. Urinary debris occurred in 6 men (75%), with a median duration of 12 days. Median overall International Index of Erectile Function-15 (IIEF-15) scores were similar at baseline and at 6 to 12 months (p=0.060), as were median IIEF-15 scores for intercourse satisfaction (p=0.433), sexual desire (p=0.622), and overall satisfaction (p=0.256). There was an improvement in lower urinary tract symptoms, assessed by International Prostate Symptom Score (IPSS), between baseline and 6 to 12 months (p=0.026). All 8 men with no baseline urinary incontinence were leak-free and pad-free by 9 months. No histological evidence of cancer was identified in 7 of 8 men biopsied at 6 months (87,5%); overall, the entire population (8 patients) was free of clinically significant cancer and had no evidence of disease on multi-parametric MRI at 6 to 12 months. MR guided Focused Ultrasound focal therapy of individual prostate cancer lesions, whether multifocal or unifocal, leads to a low rate of genitourinary side-effects and an encouraging rate of early absence of clinically significant prostate cancer.

Observations of Convectively Coupled Kelvin Waves forced by Extratropical Wave Activity

NASA Astrophysics Data System (ADS)

Kiladis, G. N.; Biello, J. A.; Straub, K. H.

2012-12-01

It is well established by observations that deep tropical convection can in certain situations be forced by extratropical Rossby wave activity. Such interactions are a well-known feature of regions of upper level westerly flow, and in particular where westerlies and equatorward wave guiding by the basic state occur at low enough latitudes to interact with tropical and subtropical moisture sources. In these regions convection is commonly initiated ahead of upper level troughs, characteristic of forcing by quasi-geostrophic dynamics. However, recent observational evidence indicates that extratropical wave activity is also associated with equatorial convection even in regions where there is a "critical line" to Rossby wave propagation at upper levels, that is, where the zonal phase speed of the wave is equal to the zonal flow speed. A common manifestation of this type of interaction involves the initiation of convectively coupled Kelvin waves, as well as mixed Rossby-gravity (MRG) waves. These waves are responsible for a large portion of the convective variability within the ITCZ over the Indian, Pacific, and Atlantic sectors, as well as within the Amazon Basin of South America. For example, Kelvin waves originating within the western Pacific ITCZ are often triggered by Rossby wave activity propagating into the Australasian region from the South Indian Ocean extratropics. At other times, Kelvin waves are seen to originate along the eastern slope of the Andes. In the latter case the initial forcing is sometimes linked to a low-level "pressure surge," initiated by wave activity propagating equatorward from the South Pacific storm track. In yet other cases, such as over Africa, the forcing appears to be related to wave activity in the extratropics which is not necessarily propagating into low latitudes, but appears to "project" onto the Kelvin structure, in line with past theoretical and modeling studies. Observational evidence for extratropical forcing of Kelvin and MRG waves will be presented, and the seasonality of these statistical associations will be discussed. Extratropical forcing of equatorial waves appears to be most efficient during the solstice seasons by waves originating within the winter hemisphere and interacting with convection in the summer hemisphere. A companion presentation by J. Biello will examine the theoretical basis for these interactions.

Endogenous protein and enzyme fragments induce immunoglobulin E-independent activation of mast cells via a G protein-coupled receptor, MRGPRX2.

PubMed

Tatemoto, K; Nozaki, Y; Tsuda, R; Kaneko, S; Tomura, K; Furuno, M; Ogasawara, H; Edamura, K; Takagi, H; Iwamura, H; Noguchi, M; Naito, T

2018-05-01

Mast cells play a central role in inflammatory and allergic reactions by releasing inflammatory mediators through 2 main pathways, immunoglobulin E-dependent and E-independent activation. In the latter pathway, mast cells are activated by a diverse range of basic molecules (collectively known as basic secretagogues) through Mas-related G protein-coupled receptors (MRGPRs). In addition to the known basic secretagogues, here, we discovered several endogenous protein and enzyme fragments (such as chaperonin-10 fragment) that act as bioactive peptides and induce immunoglobulin E-independent mast cell activation via MRGPRX2 (previously known as MrgX2), leading to the degranulation of mast cells. We discuss the possibility that MRGPRX2 responds various as-yet-unidentified endogenous ligands that have specific characteristics, and propose that MRGPRX2 plays an important role in regulating inflammatory responses to endogenous harmful stimuli, such as protein breakdown products released from damaged or dying cells. © 2018 The Foundation for the Scandinavian Journal of Immunology.

Synthetic phytochelatin surface display in Cupriavidus metallidurans CH34 for enhanced metals bioremediation.

PubMed

Biondo, Ronaldo; da Silva, Felipe Almeida; Vicente, Elisabete José; Souza Sarkis, Jorge Eduardo; Schenberg, Ana Clara Guerrini

2012-08-07

This work describes the effects of the cell surface display of a synthetic phytochelatin in the highly metal tolerant bacterium Cupriavidus metallidurans CH34. The EC20sp synthetic phytochelatin gene was fused between the coding sequences of the signal peptide (SS) and of the autotransporter β-domain of the Neisseria gonorrhoeae IgA protease precursor (IgAβ), which successfully targeted the hybrid protein toward the C. metallidurans outer membrane. The expression of the SS-EC20sp-IgAβ gene fusion was driven by a modified version of the Bacillus subtilis mrgA promoter showing high level basal gene expression that is further enhanced by metal presence in C. metallidurans. The recombinant strain showed increased ability to immobilize Pb(2+), Zn(2+), Cu(2+), Cd(2+), Mn(2+), and Ni(2+) ions from the external medium when compared to the control strain. To ensure plasmid stability and biological containment, the MOB region of the plasmid was replaced by the E. coli hok/sok coding sequence.

A functional genomics screen identifies an Importin-α homolog as a regulator of stem cell function and tissue patterning during planarian regeneration.

PubMed

Hubert, Amy; Henderson, Jordana M; Cowles, Martis W; Ross, Kelly G; Hagen, Matthew; Anderson, Christa; Szeterlak, Claudia J; Zayas, Ricardo M

2015-10-12

Planarians are renowned for their regenerative capacity and are an attractive model for the study of adult stem cells and tissue regeneration. In an effort to better understand the molecular mechanisms underlying planarian regeneration, we performed a functional genomics screen aimed at identifying genes involved in this process in Schmidtea mediterranea. We used microarrays to detect changes in gene expression in regenerating and non-regenerating tissues in planarians regenerating one side of the head and followed this with high-throughput screening by in situ hybridization and RNAi to characterize the expression patterns and function of the differentially expressed genes. Along with five previously characterized genes (Smed-cycD, Smed-morf41/mrg-1, Smed-pdss2/dlp1, Smed-slbp, and Smed-tph), we identified 20 additional genes necessary for stem cell maintenance (Smed-sart3, Smed-smarcc-1, Smed-espl1, Smed-rrm2b-1, Smed-rrm2b-2, Smed-dkc1, Smed-emg1, Smed-lig1, Smed-prim2, Smed-mcm7, and a novel sequence) or general regenerative capability (Smed-rbap46/48-2, Smed-mcm2, Smed-ptbp1, and Smed-fen-1) or that caused tissue-specific defects upon knockdown (Smed-ddc, Smed-gas8, Smed-pgbd4, and Smed-b9d2). We also found that a homolog of the nuclear transport factor Importin-α plays a role in stem cell function and tissue patterning, suggesting that controlled nuclear import of proteins is important for regeneration. Through this work, we described the roles of several previously uncharacterized genes in planarian regeneration and implicated nuclear import in this process. We have additionally created an online database to house our in situ and RNAi data to make it accessible to the planarian research community.

Acid digestion of geological and environmental samples using open-vessel focused microwave digestion.

PubMed

Taylor, Vivien F; Toms, Andrew; Longerich, Henry P

2002-01-01

The application of open vessel focused microwave acid digestion is described for the preparation of geological and environmental samples for analysis using inductively coupled plasma-mass spectrometry (ICP-MS). The method is compared to conventional closed-vessel high pressure methods which are limited in the use of HF to break down silicates. Open-vessel acid digestion more conveniently enables the use of HF to remove Si from geological and plant samples as volatile SiF4, as well as evaporation-to-dryness and sequential acid addition during the procedure. Rock reference materials (G-2 granite, MRG-1 gabbros, SY-2 syenite, JA-1 andesite, and JB-2 and SRM-688 basalts) and plant reference materials (BCR and IAEA lichens, peach leaves, apple leaves, Durham wheat flour, and pine needles) were digested with results comparable to conventional hotplate digestion. The microwave digestion method gave poor results for granitic samples containing refractory minerals, however fusion was the preferred method of preparation for these samples. Sample preparation time was reduced from several days, using conventional hotplate digestion method, to one hour per sample using our microwave method.

Laser Interstitial Thermal Therapy Technology, Physics of Magnetic Resonance Imaging Thermometry, and Technical Considerations for Proper Catheter Placement During Magnetic Resonance Imaging-Guided Laser Interstitial Thermal Therapy.

PubMed

Patel, Nitesh V; Mian, Matthew; Stafford, R Jason; Nahed, Brian V; Willie, Jon T; Gross, Robert E; Danish, Shabbar F

2016-12-01

Laser-induced thermal therapy has become a powerful tool in the neurosurgical armamentarium. The physics of laser therapy are complex, but a sound understanding of this topic is clinically relevant, as many centers have incorporated it into their treatment algorithm, and educated patients are demanding consideration of its use for their disease. Laser ablation has been used for a wide array of intracranial lesions. Laser catheter placement is guided by stereotactic planning; however, as the procedure has popularized, the number of ways in which the catheter can be inserted has also increased. There are many technical nuances for laser placement, and, to date, there is not a clear understanding of whether any one technique is better than the other. In this review, we describe the basic physics of magnetic resonance-guided laser-induced thermal therapy and describe the several common techniques for accurate Visualase laser catheter placement in a stepwise fashion. MRg-LITT, magnetic resonance-guided laser-induced thermal therapyPAD, precision aiming device.

Intracellular And Subcellular Partitioning Of Nickel In Aureococcus Anophagefferens

NASA Astrophysics Data System (ADS)

Wang, B.; Axe, L.; Wei, L.; Bagheri, S.; Michalopoulou, Z.

2008-12-01

Brown tides are caused by Aureococcus anophagefferens, a species of Pelagophyceae, and have been observed in NY/NJ waterways effecting ecosystems by attenuating light, changing water color, reducing eelgrass beds, decreasing shellfisheries, and further impacting the food web by reducing phytoplankton. Although the impact of macronutrients and iron on A. anophagefferens has been well studied, contaminants, and specifically trace metals have not. In long-term experiments designed to investigate the growth and toxicity, Cd, Cu, Ni, and Zn exposure was evaluated over 10-13 to 10-7 M for the free metal ion. While growth was inhibited or terminated from exposure to Cd and Cu, nickel addition ([Ni2+]: 10-11.23 to 10-10.23 M) promoted A. anophagefferens growth. Short-term experiments are being conducted to better understand mechanistically nickel speciation and distribution. Both total intracellular and subcellular metal concentrations are being assessed with radio-labeled 63Ni. Subcellular fractions are defined as metal-sensitive fractions (MSF) constituting organelles, cell debris, and heat-denatured protein [HDP] and biologically detoxified metal comprising heat-stabilized protein [HSP] and metal-rich granules [MRG]. Based on subcellular distribution, aqueous [Ni2+] concentrations, and A. anophagefferens growth rates, potential reaction pathways promoting A. anophagefferens growth can be addressed.

Consideration of the effects of intense tissue heating on the RF electromagnetic fields during MRI: simulations for MRgFUS in the hip

NASA Astrophysics Data System (ADS)

Xuegang Xin, Sherman; Gu, Shiyong; Carluccio, Giuseppe; Collins, Christopher M.

2015-01-01

Due to the strong dependence of tissue electrical properties on temperature, it is important to consider the potential effects of intense tissue heating on the RF electromagnetic fields during MRI, as can occur in MR-guided focused ultrasound surgery. In principle, changes of the RF electromagnetic fields could affect both efficacy of RF pulses, and the MRI-induced RF heating (SAR) pattern. In this study, the equilibrium temperature distribution in a whole-body model with 2 mm resolution before and during intense tissue heating up to 60 °C at the target region was calculated. Temperature-dependent electric properties of tissues were assigned to the model to establish a temperature-dependent electromagnetic whole-body model in a 3T MRI system. The results showed maximum changes in conductivity, permittivity, ≤ft|\\mathbf{B}1+\\right|, and SAR of about 25%, 6%, 2%, and 20%, respectively. Though the B1 field and SAR distributions are both temperature-dependent, the potential harm to patients due to higher SARs is expected to be minimal and the effects on the B1 field distribution should have minimal effect on images from basic MRI sequences.

Emerging Applications of Therapeutic Ultrasound in Neuro-oncology: Moving Beyond Tumor Ablation.

PubMed

Hersh, David S; Kim, Anthony J; Winkles, Jeffrey A; Eisenberg, Howard M; Woodworth, Graeme F; Frenkel, Victor

2016-11-01

: Transcranial focused ultrasound (FUS) can noninvasively transmit acoustic energy with a high degree of accuracy and safety to targets and regions within the brain. Technological advances, including phased-array transducers and real-time temperature monitoring with magnetic resonance thermometry, have created new opportunities for FUS research and clinical translation. Neuro-oncology, in particular, has become a major area of interest because FUS offers a multifaceted approach to the treatment of brain tumors. FUS has the potential to generate cytotoxicity within tumor tissue, both directly via thermal ablation and indirectly through radiosensitization and sonodynamic therapy; to enhance the delivery of therapeutic agents to brain tumors by transiently opening the blood-brain barrier or improving distribution through the brain extracellular space; and to modulate the tumor microenvironment to generate an immune response. In this review, we describe each of these applications for FUS, the proposed mechanisms of action, and the preclinical and clinical studies that have set the foundation for using FUS in neuro-oncology. BBB, blood-brain barrierCED, convection-enhanced delivery5-Ala, 5-aminolevulinic acidFUS, focused ultrasoundGBM, glioblastoma multiformeHSP, heat shock proteinMRgFUS, magnetic resonance-guided focused ultrasoundpFUS, pulsed focused ultrasound.

MRI-Guided Focused Ultrasound as a New Method of Drug Delivery

PubMed Central

Thanou, M.; Gedroyc, W.

2013-01-01

Ultrasound-mediated drug delivery under the guidance of an imaging modality can improve drug disposition and achieve site-specific drug delivery. The term focal drug delivery has been introduced to describe the focal targeting of drugs in tissues with the help of imaging and focused ultrasound. Focal drug delivery aims to improve the therapeutic profile of drugs by improving their specificity and their permeation in defined areas. Focused-ultrasound- (FUS-) mediated drug delivery has been applied with various molecules to improve their local distribution in tissues. FUS is applied with the aid of microbubbles to enhance the permeability of bioactive molecules across BBB and improve drug distribution in the brain. Recently, FUS has been utilised in combination with MRI-labelled liposomes that respond to temperature increase. This strategy aims to “activate” nanoparticles to release their cargo locally when triggered by hyperthermia induced by FUS. MRI-guided FUS drug delivery provides the opportunity to improve drug bioavailability locally and therefore improve the therapeutic profiles of drugs. This drug delivery strategy can be directly translated to clinic as MRg FUS is a promising clinically therapeutic approach. However, more basic research is required to understand the physiological mechanism of FUS-enhanced drug delivery. PMID:23738076

Construction and Initial Tests of MAIZE: 1 MA LTD-Driven Z-Pinch *

NASA Astrophysics Data System (ADS)

Gilgenbach, R. M.; Gomez, M. R.; Zier, J. C.; Tang, W.; French, D. M.; Lau, Y. Y.; Mazarakis, M. G.; Cuneo, M. E.; Johnston, M. D.; Oliver, B. V.; Mehlhorn, T. A.; Kim, A. A.; Sinebryukhov, V. A.

2008-11-01

We report construction and initial testing of a 1-MA Linear Transformer Driver (LTD), The Michigan Accelerator for Inductive Z-pinch Experiments, (MAIZE). This machine, the first of its type to reach the USA, is based on the joint HCEI, Sandia Laboratories, and UM development effort. The compact LTD uses 80 capacitors and 40 spark gap switches, in 40 ``bricks'', to deliver 1 MA, 100 kV pulses with 70 ns risetime into a matched resistive load. Test results will be presented for a single brick and the full LTD. Design and construction will be presented of a low-inductance MITL. Experimental research programs under design and construction at UM include: a) Studies of Magneto-Raleigh-Taylor Instability of planar foils, and b) Vacuum convolute studies including cathode and anode plasma. Theory and simulation results will be presented for these planned experiments. Initial experimental designs and moderate-current feasibility experiments will be discussed. *Research supported by U. S. DoE through Sandia National Laboratories award document numbers 240985, 768225, 790791 and 805234 to the UM. MRG supported by NNSA Fellowship and JCZ supported by NPSC Fellowship / Sandia National Labs.

Active MRI tracking for robotic assisted FUS

NASA Astrophysics Data System (ADS)

Xiao, Xu; Huang, Zhihong; Melzer, Andreas

2017-03-01

MR guided FUS is a noninvasive method producing thermal necrosis at the position of tumors with high accuracy and temperature control. Because the typical size of the ultrasound focus is smaller than the area of interested treatment tissues, focus repositioning become necessary to achieve multiple sonications to cover the whole targeted area. Using MR compatible mechanical actuators could help the ultrasound beam to reach a wider treatment range than using electrical beam steering technique and more flexibility in position the transducer. An active MR tracking technique was combined into the MRgFUS system to help locating the position of the mechanical actuator and the FUS transducer. For this study, a precise agar reference model was designed and fabricated to test the performance of the active tracking technique when it was used on the MR-compatible robotics InnoMotion™ (IBSMM, Engineering spol. s r.o. / Ltd, Czech Republic). The precision, tracking range and positioning speed of the combined robotic FUS system were evaluated in this study. Compared to the existing MR guided HIFU systems, the combined robotic system with active tracking techniques provides a potential that allows the FUS treatment to operate in a larger spatial range and with a faster speed, which is one of the main challenges for organ motion tracking.

Application of MR-guided focused pulsed ultrasound for destroying clots in vitro using thrombolytic drugs

NASA Astrophysics Data System (ADS)

Hadjisavvas, V.; Ioannides, K.; Damianou, C.

2011-09-01

In this paper an MR-guided focused pulsed ultrasound system for the treatment of stroke using thrombolytic drugs in a model in vitro is presented. A single element spherically focused transducer of 5 cm diameter; focusing at 10 cm and operating at 0.5 MHz or 1 MHz was used. The transducer was mounted in an MR compatible robot. The artery was modelled using a silicone tube. Tissue was modelled using polyaclylimide gel. Coagulated blood was used to model thrombus. A thermocouple was placed in the thrombus in order to measure the thrombus temperature. The effect of power, beam, and frequency was investigated. The goal was to maintain a temperature increase of less than 1 °C during the application of pulse ultrasound (called safe temperature). With the application of ultrasound alone there was no notable destruction of the thrombus. With the combination of ultrasound and thrombolytic drugs destruction occurred after 60 mins of pulse exposure (PRF = 1 s, duty factor = 10%, and with thrombus placed at 1 cm deep in the tissue). This simple in vitro model was proven very successful for evaluating MRgFUS as a modality for treating stroke. In the future we plan to apply this treatment protocol in live animals and humans.

Resistance of Bacillus subtilis Spore DNA to Lethal Ionizing Radiation Damage Relies Primarily on Spore Core Components and DNA Repair, with Minor Effects of Oxygen Radical Detoxification

PubMed Central

Raguse, Marina; Reitz, Günther; Okayasu, Ryuichi; Li, Zuofeng; Klein, Stuart; Setlow, Peter; Nicholson, Wayne L.

2014-01-01

The roles of various core components, including α/β/γ-type small acid-soluble spore proteins (SASP), dipicolinic acid (DPA), core water content, and DNA repair by apurinic/apyrimidinic (AP) endonucleases or nonhomologous end joining (NHEJ), in Bacillus subtilis spore resistance to different types of ionizing radiation including X rays, protons, and high-energy charged iron ions have been studied. Spores deficient in DNA repair by NHEJ or AP endonucleases, the oxidative stress response, or protection by major α/β-type SASP, DPA, and decreased core water content were significantly more sensitive to ionizing radiation than wild-type spores, with highest sensitivity to high-energy-charged iron ions. DNA repair via NHEJ and AP endonucleases appears to be the most important mechanism for spore resistance to ionizing radiation, whereas oxygen radical detoxification via the MrgA-mediated oxidative stress response or KatX catalase activity plays only a very minor role. Synergistic radioprotective effects of α/β-type but not γ-type SASP were also identified, indicating that α/β-type SASP's binding to spore DNA is important in preventing DNA damage due to reactive oxygen species generated by ionizing radiation. PMID:24123749

Inter-costal Liver Ablation Under Real Time MR-Thermometry With Partial Activation Of A HIFU Phased Array Transducer

NASA Astrophysics Data System (ADS)

Quesson, Bruno; Merle, Mathilde; Köhler, Max; Mougenot, Charles; Roujol, Sebastien; de Senneville, Baudouin Denis; Moonen, Chrit

2010-03-01

HIFU ablation of tumours located inside the liver is hampered by the rib cage, which partially obstructs the beam path and may create adverse effects such as skin burns. This study presents a method for selectively deactivating the transducer elements causing undesired temperature increases near the bones. A manual segmentation of the bones visualized on 3D anatomical MR images acquired prior to sonication was performed to identify the beam obstruction. The resulting mask was projected (ray tracing starting from the focal point) on the transducer and elements with more than 50% obstruction of their active surface were deactivated. The effectiveness of the method for HIFU ablations is demonstrated ex vivo and in vivo in the liver of pigs with real-time MR thermometry, using the proton resonant frequency (PRF) method. For both ex vivo and in vivo experiments, the temperature increase near the bones was significantly reduced when the elements located in front of the ribs were deactivated. The temperature evolution at the focal point were similar, indicative of the absence of loss of heating efficacy when the elements were deactivated. This method is simple, rapid and reliable and allows to perform intercostal MRgHIFU ablation of the liver while sparing the ribs.

Fate of antibiotic and metal resistance genes during two-phase anaerobic digestion of residue sludge revealed by metagenomic approach.

PubMed

Wu, Ying; Cui, Erping; Zuo, Yiru; Cheng, Weixiao; Chen, Hong

2018-05-01

The prevalence and persistence of antibiotic resistance genes in wastewater treatment plants (WWTPs) is of growing interest, and residual sludge is among the main sources for the release of antibiotic resistance genes (ARGs). Moreover, heavy metals concentrated in dense microbial communities of sludge could potentially favor co-selection of ARGs and metal resistance genes (MRGs). Residual sludge treatment is needed to limit the spread of resistance from WWTPs into the environment. This study aimed to explore the fate of ARGs and MRGs during thermophilic two-phase (acidogenic/methanogenic phase) anaerobic digestion by metagenomic analysis. The occurrence and abundance of mobile genetic elements were also determined based on the SEED database. Among the 27 major ARG subtypes detected in feed sludge, large reductions (> 50%) in 6 ARG subtypes were achieved by acidogenic phase (AP), while 63.0% of the ARG subtypes proliferated in the following methanogenic phase (MP). In contrast, a 2.8-fold increase in total MRG abundance was found in AP, while the total abundance during MP decreased to the same order of magnitude as in feed sludge. The distinct dynamics of ARGs and MRGs during the two-phase anaerobic digestion are noteworthy, and more specific treatments are required to limit their proliferation in the environment.

Uterine fibroids: current perspectives

PubMed Central

Khan, Aamir T; Shehmar, Manjeet; Gupta, Janesh K

2014-01-01

Uterine fibroids are a major cause of morbidity in women of a reproductive age (and sometimes even after menopause). There are several factors that are attributed to underlie the development and incidence of these common tumors, but this further corroborates their relatively unknown etiology. The most likely presentation of fibroids is by their effect on the woman’s menstrual cycle or pelvic pressure symptoms. Leiomyosarcoma is a very rare entity that should be suspected in postmenopausal women with fibroid growth (and no concurrent hormone replacement therapy). The gold standard diagnostic modality for uterine fibroids appears to be gray-scale ultrasonography, with magnetic resonance imaging being a close second option in complex clinical circumstances. The management of uterine fibroids can be approached medically, surgically, and even by minimal access techniques. The recent introduction of selective progesterone receptor modulators (SPRMs) and aromatase inhibitors has added more armamentarium to the medical options of treatment. Uterine artery embolization (UAE) has now been well-recognized as a uterine-sparing (fertility-preserving) method of treating fibroids. More recently, the introduction of ultrasound waves (MRgFUS) or radiofrequency (VizAblate™ and Acessa™) for uterine fibroid ablation has added to the options of minimal access treatment. More definite surgery in the form of myomectomy or hysterectomy can be performed via the minimal access or open route methods. Our article seeks to review the already established information on uterine fibroids with added emphasis on contemporary knowledge. PMID:24511243

Real-time method for motion-compensated MR thermometry and MRgHIFU treatment in abdominal organs.

PubMed

Celicanin, Zarko; Auboiroux, Vincent; Bieri, Oliver; Petrusca, Lorena; Santini, Francesco; Viallon, Magalie; Scheffler, Klaus; Salomir, Rares

2014-10-01

Magnetic resonance-guided high-intensity focused ultrasound is considered to be a promising treatment for localized cancer in abdominal organs such as liver, pancreas, or kidney. Abdominal motion, anatomical arrangement, and required sustained sonication are the main challenges. MR acquisition consisted of thermometry performed with segmented gradient-recalled echo echo-planar imaging, and a segment-based one-dimensional MR navigator parallel to the main axis of motion to track the organ motion. This tracking information was used in real-time for: (i) prospective motion correction of MR thermometry and (ii) HIFU focal point position lock-on target. Ex vivo experiments were performed on a sheep liver and a turkey pectoral muscle using a motion demonstrator, while in vivo experiments were conducted on two sheep liver. Prospective motion correction of MR thermometry yielded good signal-to-noise ratio (range, 25 to 35) and low geometric distortion due to the use of segmented EPI. HIFU focal point lock-on target yielded isotropic in-plane thermal build-up. The feasibility of in vivo intercostal liver treatment was demonstrated in sheep. The presented method demonstrated in moving phantoms and breathing sheep accurate motion-compensated MR thermometry and precise HIFU focal point lock-on target using only real-time pencil-beam navigator tracking information, making it applicable without any pretreatment data acquisition or organ motion modeling. Copyright © 2013 Wiley Periodicals, Inc.

MR-ARFI-based method for the quantitative measurement of tissue elasticity: application for monitoring HIFU therapy

NASA Astrophysics Data System (ADS)

Vappou, Jonathan; Bour, Pierre; Marquet, Fabrice; Ozenne, Valery; Quesson, Bruno

2018-05-01

Monitoring thermal therapies through medical imaging is essential in order to ensure that they are safe, efficient and reliable. In this paper, we propose a new approach, halfway between MR acoustic radiation force imaging (MR-ARFI) and MR elastography (MRE), allowing for the quantitative measurement of the elastic modulus of tissue in a highly localized manner. It relies on the simulation of the MR-ARFI profile, which depends on tissue biomechanical properties, and on the identification of tissue elasticity through the fitting of experimental displacement images measured using rapid MR-ARFI. This method was specifically developed to monitor MR-guided high intensity focused ultrasound (MRgHIFU) therapy. Elasticity changes were followed during HIFU ablations (N  =  6) performed ex vivo in porcine muscle samples, and were compared to temperature changes measured by MR-thermometry. Shear modulus was found to increase consistently and steadily a few seconds after the heating started, and such changes were found to be irreversible. The shear modulus was found to increase from 1.49  ±  0.48 kPa (before ablation) to 3.69  ±  0.93 kPa (after ablation and cooling). Thanks to its ability to perform quantitative elasticity measurements in a highly localized manner around the focal spot, this method proved to be particularly attractive for monitoring HIFU ablations.

PfeT, a P1B4 -type ATPase, effluxes ferrous iron and protects Bacillus subtilis against iron intoxication.

PubMed

Guan, Guohua; Pinochet-Barros, Azul; Gaballa, Ahmed; Patel, Sarju J; Argüello, José M; Helmann, John D

2015-11-01

Iron is an essential element for nearly all cells and limited iron availability often restricts growth. However, excess iron can also be deleterious, particularly when cells expressing high affinity iron uptake systems transition to iron rich environments. Bacillus subtilis expresses numerous iron importers, but iron efflux has not been reported. Here, we describe the B. subtilis PfeT protein (formerly YkvW/ZosA) as a P1B4 -type ATPase in the PerR regulon that serves as an Fe(II) efflux pump and protects cells against iron intoxication. Iron and manganese homeostasis in B. subtilis are closely intertwined: a pfeT mutant is iron sensitive, and this sensitivity can be suppressed by low levels of Mn(II). Conversely, a pfeT mutant is more resistant to Mn(II) overload. In vitro, the PfeT ATPase is activated by both Fe(II) and Co(II), although only Fe(II) efflux is physiologically relevant in wild-type cells, and null mutants accumulate elevated levels of intracellular iron. Genetic studies indicate that PfeT together with the ferric uptake repressor (Fur) cooperate to prevent iron intoxication, with iron sequestration by the MrgA mini-ferritin playing a secondary role. Protection against iron toxicity may also be a key role for related P1B4 -type ATPases previously implicated in bacterial pathogenesis. © 2015 John Wiley & Sons Ltd.

Identification of testis-specific male contraceptive targets: insights from transcriptional profiling of the cycle of the rat seminiferous epithelium and purified testicular cells.

PubMed

Johnston, Daniel S; Jelinsky, Scott A; Zhi, Yu; Finger, Joshua N; Kopf, Gregory S; Wright, William W

2007-12-01

In an effort to identify novel targets for the development of nonhormonal male contraceptives, genome-wide transcriptional profiling of the rat testis was performed. Specifically, enzymatically purified spermatogonia plus early spermatocyctes, pachytene spermatocytes, round spermatids, and Sertoli cells was analyzed along with microdissected rat seminiferous tubules at stages I, II-III, IV-V, VI, VIIa,b, VIIc,d, VIII, IX- XI, XII, XIII-XIV of the cycle of the seminiferous epithelium using RAE 230_2.0 microarrays. The combined analysis of these studies identified 16,971 expressed probe sets on the array. How these expression data, combined with additional bioinformatic data analysis and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis, led to the identification of 58 genes that have 1000-fold higher expression transcriptionally in the testis when compared to over 20 other nonreproductive tissues is described. The products of these genes may play important roles in testicular and/or sperm function, and further investigation on their utility as nonhormonal contraceptive targets is warranted. Moreover, these microarray data have been used to expedite the identification of a mutation in RIKEN cDNA 2410004F06 gene as likely being responsible for spermatogenic failure in a line of infertile mice generated by N-ethyl-N-nitrosourea (ENU) mutagenesis. The microarray data and the qRT-PCR data described are available in the Mammalian Reproductive Genetics database (http://mrg.genetics.washington.edu/).

MRI monitoring of focused ultrasound sonications near metallic hardware.

PubMed

Weber, Hans; Ghanouni, Pejman; Pascal-Tenorio, Aurea; Pauly, Kim Butts; Hargreaves, Brian A

2018-07-01

To explore the temperature-induced signal change in two-dimensional multi-spectral imaging (2DMSI) for fast thermometry near metallic hardware to enable MR-guided focused ultrasound surgery (MRgFUS) in patients with implanted metallic hardware. 2DMSI was optimized for temperature sensitivity and applied to monitor focus ultrasound surgery (FUS) sonications near metallic hardware in phantoms and ex vivo porcine muscle tissue. Further, we evaluated its temperature sensitivity for in vivo muscle in patients without metallic hardware. In addition, we performed a comparison of temperature sensitivity between 2DMSI and conventional proton-resonance-frequency-shift (PRFS) thermometry at different distances from metal devices and different signal-to-noise ratios (SNR). 2DMSI thermometry enabled visualization of short ultrasound sonications near metallic hardware. Calibration using in vivo muscle yielded a constant temperature sensitivity for temperatures below 43 °C. For an off-resonance coverage of ± 6 kHz, we achieved a temperature sensitivity of 1.45%/K, resulting in a minimum detectable temperature change of ∼2.5 K for an SNR of 100 with a temporal resolution of 6 s per frame. The proposed 2DMSI thermometry has the potential to allow MR-guided FUS treatments of patients with metallic hardware and therefore expand its reach to a larger patient population. Magn Reson Med 80:259-271, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

High intensity focused ultrasound ablation of goat liver in vivo: Pathologic changes of portal vein and the "heat-sink" effect.

PubMed

Jiang, F; He, M; Liu, Y J; Wang, Z B; Zhang, L; Bai, J

2013-01-01

The purpose of this study was to evaluate pathological changes of the portal vein (PV) and the effects on main branches of the hepatic PV during HIFU (high-intensity focused ultrasound) sonication when liver tissue adjacent to the main branches of hepatic PV was ablated. Normal liver tissue at 0mm, 5mm, 10mm away from the hepatic portal vein in 50 healthy goats was ablated with magnetic resonance image-guided HIFU (MRgHIFU). MRI showed a non-perfusion region at the target area but did not show any significant changes of the PV immediately after HIFU. The histological examination 1 day after HIFU showed coagulative necrosis at the target area, revealed deep-dyed swelling collagen (CS) fibers and vessel wall fracture (VWF) in the PV adjacent to the target area; however, no CS or VWF was observed in the PV 1 week after HIFU ablation. The energy required to ablate the foci at 0mm was 21% more than that at 10mm from the PV (p<0.05); the energy needed to ablate foci 5mm away from the PV was 10% more than that at 10mm from the PV (p<0.05). We concluded that minor injury of the hepatic portal vein may occur when ablating the adjacent liver tissue, and the acoustic energy deposition is related to the distance to the portal vein. Copyright © 2012 Elsevier B.V. All rights reserved.

A New Generation of Real-Time Systems in the JET Tokamak

NASA Astrophysics Data System (ADS)

Alves, Diogo; Neto, Andre C.; Valcarcel, Daniel F.; Felton, Robert; Lopez, Juan M.; Barbalace, Antonio; Boncagni, Luca; Card, Peter; De Tommasi, Gianmaria; Goodyear, Alex; Jachmich, Stefan; Lomas, Peter J.; Maviglia, Francesco; McCullen, Paul; Murari, Andrea; Rainford, Mark; Reux, Cedric; Rimini, Fernanda; Sartori, Filippo; Stephen, Adam V.; Vega, Jesus; Vitelli, Riccardo; Zabeo, Luca; Zastrow, Klaus-Dieter

2014-04-01

Recently, a new recipe for developing and deploying real-time systems has become increasingly adopted in the JET tokamak. Powered by the advent of x86 multi-core technology and the reliability of JET's well established Real-Time Data Network (RTDN) to handle all real-time I/O, an official Linux vanilla kernel has been demonstrated to be able to provide real-time performance to user-space applications that are required to meet stringent timing constraints. In particular, a careful rearrangement of the Interrupt ReQuests' (IRQs) affinities together with the kernel's CPU isolation mechanism allows one to obtain either soft or hard real-time behavior depending on the synchronization mechanism adopted. Finally, the Multithreaded Application Real-Time executor (MARTe) framework is used for building applications particularly optimised for exploring multi-core architectures. In the past year, four new systems based on this philosophy have been installed and are now part of JET's routine operation. The focus of the present work is on the configuration aspects that enable these new systems' real-time capability. Details are given about the common real-time configuration of these systems, followed by a brief description of each system together with results regarding their real-time performance. A cycle time jitter analysis of a user-space MARTe based application synchronizing over a network is also presented. The goal is to compare its deterministic performance while running on a vanilla and on a Messaging Real time Grid (MRG) Linux kernel.

TU-EF-210-02: MRg Hyperthermia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chopra, R.

2015-06-15

The use of therapeutic ultrasound to provide targeted therapy is an active research area that has a broad application scope. The invited talks in this session will address currently implemented strategies and protocols for both hyperthermia and ablation applications using therapeutic ultrasound. The role of both ultrasound and MRI in the monitoring and assessment of these therapies will be explored in both pre-clinical and clinical applications. Katherine Ferrara: High Intensity Focused Ultrasound, Drug Delivery, and Immunotherapy Rajiv Chopra: Translating Localized Doxorubicin Delivery to Pediatric Oncology using MRI-guided HIFU Elisa Konofagou: Real-time Ablation Monitoring and Lesion Quantification using Harmonic Motion Imagingmore » Keyvan Farahani: AAPM Task Groups in Interventional Ultrasound Imaging and Therapy Learning Objectives: Understand the role of ultrasound in localized drug delivery and the effects of immunotherapy when used in conjunction with ultrasound therapy. Understand potential targeted drug delivery clinical applications including pediatric oncology. Understand the technical requirements for performing targeted drug delivery. Understand how radiation-force approaches can be used to both monitor and assess high intensity focused ultrasound ablation therapy. Understand the role of AAPM task groups in ultrasound imaging and therapies. Chopra: Funding from Cancer Prevention and Research Initiative of Texas (CPRIT), Award R1308 Evelyn and M.R. Hudson Foundation; Research Support from Research Contract with Philips Healthcare; COI are Co-founder of FUS Instruments Inc Ferrara: Supported by NIH, UCDavis and California (CIRM and BHCE) Farahani: In-kind research support from Philips Healthcare.« less

Image-guided Navigation of Single-element Focused Ultrasound Transducer

PubMed Central

Kim, Hyungmin; Chiu, Alan; Park, Shinsuk; Yoo, Seung-Schik

2014-01-01

The spatial specificity and controllability of focused ultrasound (FUS), in addition to its ability to modify the excitability of neural tissue, allows for the selective and reversible neuromodulation of the brain function, with great potential in neurotherapeutics. Intra-operative magnetic resonance imaging (MRI) guidance (in short, MRg) has limitations due to its complicated examination logistics, such as fixation through skull screws to mount the stereotactic frame, simultaneous sonication in the MRI environment, and restrictions in choosing MR-compatible materials. In order to overcome these limitations, an image-guidance system based on optical tracking and pre-operative imaging data is developed, separating the imaging acquisition for guidance and sonication procedure for treatment. Techniques to define the local coordinates of the focal point of sonication are presented. First, mechanical calibration detects the concentric rotational motion of a rigid-body optical tracker, attached to a straight rod mimicking the sonication path, pivoted at the virtual FUS focus. The spatial error presented in the mechanical calibration was compensated further by MRI-based calibration, which estimates the spatial offset between the navigated focal point and the ground-truth location of the sonication focus obtained from a temperature-sensitive MR sequence. MRI-based calibration offered a significant decrease in spatial errors (1.9±0.8 mm; 57% reduction) compared to the mechanical calibration method alone (4.4±0.9 mm). Using the presented method, pulse-mode FUS was applied to the motor area of the rat brain, and successfully stimulated the motor cortex. The presented techniques can be readily adapted for the transcranial application of FUS to intact human brain. PMID:25232203

Roles of Mas-related G protein-coupled receptor X2 on mast cell-mediated host defense, pseudoallergic drug reactions, and chronic inflammatory diseases.

PubMed

Subramanian, Hariharan; Gupta, Kshitij; Ali, Hydar

2016-09-01

Mast cells (MCs), which are granulated tissue-resident cells of hematopoietic lineage, contribute to vascular homeostasis, innate/adaptive immunity, and wound healing. However, MCs are best known for their roles in allergic and inflammatory diseases, such as anaphylaxis, food allergy, rhinitis, itch, urticaria, atopic dermatitis, and asthma. In addition to the high-affinity IgE receptor (FcεRI), MCs express numerous G protein-coupled receptors (GPCRs), which are the largest group of membrane receptor proteins and the most common targets of drug therapy. Antimicrobial host defense peptides, neuropeptides, major basic protein, eosinophil peroxidase, and many US Food and Drug Administration-approved peptidergic drugs activate human MCs through a novel GPCR known as Mas-related G protein-coupled receptor X2 (MRGPRX2; formerly known as MrgX2). Unique features of MRGPRX2 that distinguish it from other GPCRs include their presence both on the plasma membrane and intracellular sites and their selective expression in MCs. In this article we review the possible roles of MRGPRX2 on host defense, drug-induced anaphylactoid reactions, neurogenic inflammation, pain, itch, and chronic inflammatory diseases, such as urticaria and asthma. We propose that host defense peptides that kill microbes directly and activate MCs through MRGPRX2 could serve as novel GPCR targets to modulate host defense against microbial infection. Furthermore, mAbs or small-molecule inhibitors of MRGPRX2 could be developed for the treatment of MC-dependent allergic and inflammatory disorders. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Group-based developmental BMI trajectories, polycystic ovary syndrome, and gestational diabetes: a community-based longitudinal study.

PubMed

Kakoly, Nadira Sultana; Earnest, Arul; Moran, Lisa J; Teede, Helena J; Joham, Anju E

2017-11-06

Obesity is common in young women, increasing insulin resistance (IR) and worsening pregnancy complications, including gestational diabetes (GDM). Women with polycystic ovary syndrome (PCOS) are commonly obese, which aggravates the severity of PCOS clinical expression. Relationships between these common insulin-resistant conditions, however, remain unclear. We conducted a secondary analysis of the Australian Longitudinal Study on Women's Health (ALSWH) database, including data from 8009 women aged 18-36 years across six surveys. We used latent-curve growth modelling to identify distinct body mass index (BMI) trajectories and multinomial logistic regression to explore sociodemographic and health variables characterizing BMI group membership. Logistic regression was used to assess independent risk of GDM. A total of 662 women (8.29%, 95% CI 7.68-8.89) reported PCOS. Three distinct BMI trajectories emerged, namely low stable (LSG) (63.8%), defined as an average trajectory remaining at ~25 kg/m 2 ; moderately rising (MRG) (28.8%), a curvilinear trajectory commencing in a healthy BMI and terminating in the overweight range; and high-rising (HRG) (7.4%), a curvilinear trajectory starting and terminating in the obese range. A high BMI in early reproductive life predicted membership in higher trajectories. The HRG BMI trajectory was independently associated with GDM (OR 2.50, 95% CI 1.80-3.48) and was a stronger correlate than PCOS (OR 1.89, 95% CI 1.41-2.54), maternal age, socioeconomic status, or parity. Our results suggest heterogeneity in BMI change among Australian women of reproductive age, with and without PCOS. Reducing early adult life weight represents an ideal opportunity to intervene at an early stage of reproductive life and decreases the risk of long-term metabolic complications such as GDM.

ACE2 and vasoactive peptides: novel players in cardiovascular/renal remodeling and hypertension.

PubMed

Mendoza-Torres, Evelyn; Oyarzún, Alejandra; Mondaca-Ruff, David; Azocar, Andrés; Castro, Pablo F; Jalil, Jorge E; Chiong, Mario; Lavandero, Sergio; Ocaranza, María Paz

2015-08-01

The renin-angiotensin system (RAS) is a key component of cardiovascular physiology and homeostasis due to its influence on the regulation of electrolyte balance, blood pressure, vascular tone and cardiovascular remodeling. Deregulation of this system contributes significantly to the pathophysiology of cardiovascular and renal diseases. Numerous studies have generated new perspectives about a noncanonical and protective RAS pathway that counteracts the proliferative and hypertensive effects of the classical angiotensin-converting enzyme (ACE)/angiotensin (Ang) II/angiotensin type 1 receptor (AT1R) axis. The key components of this pathway are ACE2 and its products, Ang-(1-7) and Ang-(1-9). These two vasoactive peptides act through the Mas receptor (MasR) and AT2R, respectively. The ACE2/Ang-(1-7)/MasR and ACE2/Ang-(1-9)/AT2R axes have opposite effects to those of the ACE/Ang II/AT1R axis, such as decreased proliferation and cardiovascular remodeling, increased production of nitric oxide and vasodilation. A novel peptide from the noncanonical pathway, alamandine, was recently identified in rats, mice and humans. This heptapeptide is generated by catalytic action of ACE2 on Ang A or through a decarboxylation reaction on Ang-(1-7). Alamandine produces the same effects as Ang-(1-7), such as vasodilation and prevention of fibrosis, by interacting with Mas-related GPCR, member D (MrgD). In this article, we review the key roles of ACE2 and the vasoactive peptides Ang-(1-7), Ang-(1-9) and alamandine as counter-regulators of the ACE-Ang II axis as well as the biological properties that allow them to regulate blood pressure and cardiovascular and renal remodeling. © The Author(s), 2015.

Timing considerations for preclinical MRgRT: effects of ion diffusion, SNR and imaging times on FXG gel calibration

NASA Astrophysics Data System (ADS)

Welch, M.; Foltz, W. D.; Jaffray, D. A.

2015-01-01

Sub-millimeter resolution images are required for gel dosimeters to be used in preclinical research, which is challenging for MR probed ferrous xylenol-orange (FXG) dosimeters due to ion diffusion and inadequate SNR. A preclinical 7 T MR, small animal irradiator and FXG dosimeters were used in all experiments. Ion diffusion was analyzed using high resolution (0.2 mm/pixel) T1 MR images collected every 5 minutes, post-irradiation, for an hour. Using Fick's second law, ion diffusion was approximated for the first hour post-irradiation. SNR, T1 map precision and calibration fit were determined for two MR protocols: (1) 10 minute acquisition, 0.35mm/pixel and 3mm slices, (2) 45 minute acquisition, 0. 25 mm/pixel and 2 mm slices. SNR and T1 map precision were calculated using a Monte Carlo simulation. Calibration curves were determined by plotting R1 relaxation rates versus depth dose data, and fitting a linear trend line. Ion diffusion was estimated as 0.003mm2 in the first hour post-irradiation. For protocols (1) and (2) respectively, Monte Carlo simulation predicted T1 precisions of 3% and 5% within individual voxels using experimental SNRs; the corresponding measured T1 precisions were 8% and 12%. The linear trend lines reported slopes of 27 ± 3 Gy*s (R2: 0.80 ± 0.04) and 27 ± 4 Gy*s (R2: 0.90 ± 0.04). Ion diffusion is negligible within the first hour post-irradiation, and an accurate and reproducible calibration can be achieved in a preclinical setting with sub-millimeter resolution.

The effect of electronically steering a phased array ultrasound transducer on near-field tissue heating.

PubMed

Payne, Allison; Vyas, Urvi; Todd, Nick; de Bever, Joshua; Christensen, Douglas A; Parker, Dennis L

2011-09-01

This study presents the results obtained from both simulation and experimental techniques that show the effect of mechanically or electronically steering a phased array transducer on proximal tissue heating. The thermal response of a nine-position raster and a 16-mm diameter circle scanning trajectory executed through both electronic and mechanical scanning was evaluated in computer simulations and experimentally in a homogeneous tissue-mimicking phantom. Simulations were performed using power deposition maps obtained from the hybrid angular spectrum (HAS) method and applying a finite-difference approximation of the Pennes' bioheat transfer equation for the experimentally used transducer and also for a fully sampled transducer to demonstrate the effect of acoustic window, ultrasound beam overlap and grating lobe clutter on near-field heating. Both simulation and experimental results show that electronically steering the ultrasound beam for the two trajectories using the 256-element phased array significantly increases the thermal dose deposited in the near-field tissues when compared with the same treatment executed through mechanical steering only. In addition, the individual contributions of both beam overlap and grating lobe clutter to the near-field thermal effects were determined through comparing the simulated ultrasound beam patterns and resulting temperature fields from mechanically and electronically steered trajectories using the 256-randomized element phased array transducer to an electronically steered trajectory using a fully sampled transducer with 40 401 phase-adjusted sample points. Three distinctly different three distinctly different transducers were simulated to analyze the tradeoffs of selected transducer design parameters on near-field heating. Careful consideration of design tradeoffs and accurate patient treatment planning combined with thorough monitoring of the near-field tissue temperature will help to ensure patient safety during an MRgHIFU treatment.

SU-E-J-205: Dose Distribution Differences Caused by System Related Geometric Distortion in MRI-Guided Radiation Treatment System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, J; Yang, J; Wen, Z

2015-06-15

Purpose: MRI has superb soft tissue contrast but is also known for geometric distortions. The concerns and uncertainty about MRI’s geometric distortion have contributed to the hesitation of using only MRI for simulation in radiation therapy. There are two major categories of geometric distortion in MRI; system related and patient related. In this presentation, we studied the impact of system-related geometric distortion on dose distribution in a digital body phantom under an MR-Linac environment. Methods: Residual geometric distortion (after built-in geometric correction) was modeled based on phantom measurements of the system-related geometric distortions of a MRI scanner of a combinedmore » MR guided Radiation Therapy (MRgRT) system. A digital oval shaped phantom (40×25 cm) as well as one ellipsoid shaped tumor volume was created to simulate a simplified human body. The simulated tumor volume was positioned at several locations between the isocenter and the body surface. CT numbers in HUs that approximate soft tissue and tumor were assigned to the respective regions in the digital phantom. To study the effect of geometric distortion caused by system imperfections, an IMRT plan was optimized with the distorted image set with the B field. Dose distributions were re-calculated on the undistorted image set with the B field (as in MR-Linac). Results: The maximum discrepancies in both body contour and tumor boundary was less than 2 mm, which leads to small dose distribution change. For the target in the center, coverage was reduced from 98.8% (with distortion) to 98.2%; for the other peripheral target coverage was reduced from 98.4% to 95.9%. Conclusion: System related geometric distortions over the 40×25 area were within 2mm and the resulted dosimetric effects were minor for the two tumor locations in the phantom. Patient study will be needed for further investigation. The authors received a corporate research grant from Elekta.« less

Les effets des interfaces sur les proprietes magnetiques et de transport des multicouches nickel/iron et cobalt/silver

NASA Astrophysics Data System (ADS)

Veres, Teodor

Cette these est consacree a l'etude de l'evolution structurale des proprietes magnetiques et de transport des multicouches Ni/Fe et nanostructures a base de Co et de l'Ag. Dans une premiere partie, essentiellement bibliographique, nous introduisons quelques concepts de base relies aux proprietes magnetiques et de transport des multicouches metalliques. Ensuite, nous presentons une breve description des methodes d'analyse des resultats. La deuxieme partie est consacree a l'etude des proprietes magnetiques et de transport des multicouches ferromagnetiques/ferromagnetiques Ni/Fe. Nous montrerons qu'une interpretation coherente de ces proprietes necessite la prise en consideration des effets des interfaces. Nous nous attacherons a mettre en evidence, a evaluer et a etudier les effets de ces interfaces ainsi que leur evolution, et ce, suite a des traitements thermiques tel que le depot a temperature elevee et l'irradiation ionique. Les analyses correlees de la structure et de la magnetoresistance nous permettront d'emettre des conclusions sur l'influence des couches tampons entre l'interface et le substrat ainsi qu'entre les couches elles-memes sur le comportement magnetique des couches F/F. La troisieme partie est consacree aux systemes a Magneto-Resistance Geante (MRG) a base de Co et Ag. Nous allons etudier l'evolution de la microstructure suite a l'irradiation avec des ions Si+ ayant une energie de 1 MeV, ainsi que les effets de ces changements sur le comportement magnetique. Cette partie debutera par l'analyse des proprietes d'une multicouche hybride, intermediaire entre les multicouches et les materiaux granulaires. Nous analyserons a l'aide des mesures de diffraction, de relaxation superparamagnetique et de magnetoresistance, les evolutions structurales produites par l'irradiation ionique. Nous etablirons des modeles qui nous aideront a interpreter les resultats pour une serie des multicouches qui couvrent un large eventail de differents comportements magnetiques et ceci en fonction de l'epaisseur de la couche magnetique de Co. Nous verrons que dans ces systemes les effets de l'irradiation ionique sont fortement influences par l'energie de surface ainsi que par l'enthalpie de formation, largement positive pour le systeme Co/Ag.

A dual-mode hemispherical sparse array for 3D passive acoustic mapping and skull localization within a clinical MRI guided focused ultrasound device

NASA Astrophysics Data System (ADS)

Crake, Calum; Brinker, Spencer T.; Coviello, Christian M.; Livingstone, Margaret S.; McDannold, Nathan J.

2018-03-01

Previous work has demonstrated that passive acoustic imaging may be used alongside MRI for monitoring of focused ultrasound therapy. However, past implementations have generally made use of either linear arrays originally designed for diagnostic imaging or custom narrowband arrays specific to in-house therapeutic transducer designs, neither of which is fully compatible with clinical MR-guided focused ultrasound (MRgFUS) devices. Here we have designed an array which is suitable for use within an FDA-approved MR-guided transcranial focused ultrasound device, within the bore of a 3 Tesla clinical MRI scanner. The array is constructed from 5  ×  0.4 mm piezoceramic disc elements arranged in pseudorandom fashion on a low-profile laser-cut acrylic frame designed to fit between the therapeutic elements of a 230 kHz InSightec ExAblate 4000 transducer. By exploiting thickness and radial resonance modes of the piezo discs the array is capable of both B-mode imaging at 5 MHz for skull localization, as well as passive reception at the second harmonic of the therapy array for detection of cavitation and 3D passive acoustic imaging. In active mode, the array was able to perform B-mode imaging of a human skull, showing the outer skull surface with good qualitative agreement with MR imaging. Extension to 3D showed the array was able to locate the skull within  ±2 mm/2° of reference points derived from MRI, which could potentially allow registration of a patient to the therapy system without the expense of real-time MRI. In passive mode, the array was able to resolve a point source in 3D within a  ±10 mm region about each axis from the focus, detect cavitation (SNR ~ 12 dB) at burst lengths from 10 cycles to continuous wave, and produce 3D acoustic maps in a flow phantom. Finally, the array was used to detect and map cavitation associated with microbubble activity in the brain in nonhuman primates.

Metal accumulation and differentially expressed proteins in gill of oyster (Crassostrea hongkongensis) exposed to long-term heavy metal-contaminated estuary.

PubMed

Luo, Lianzhong; Ke, Caihuan; Guo, Xiaoyu; Shi, Bo; Huang, Miaoqin

2014-06-01

Bio-accumulation and bio-transmission of toxic metals and the toxicological responses of organisms exposed to toxic metals have been focused, due to heavy metal contaminations have critically threatened the ecosystem and food security. However, still few investigations focused on the responses of certain organisms exposed to the long term and severe heavy metal contamination in specific environments. In present investigation, the Hong Kong oyster, Crassostrea hongkongensis were obtained from 3 sites which were contaminated by different concentrations of heavy metals (such as zinc, copper, manganese and lead etc.), respectively. Heavy metal concentrations in the sea water samples collected from the 3 sites and the dissected tissues of the oysters with blue visceral mass were determinated to estimate the metal contamination levels in environments and the bio-accumulation ratios of the heavy metals in the different tissues of oysters. Moreover, Proteomic methods were employed to analyze the differentially expressed proteins in the gills of oysters exposed to long-term heavy metal contaminations. Results indicated that the Jiulong River estuary has been severely contaminated by Cu, Zn and slightly with Cr, Ni, Mn, etc, moreover, Zn and Cu were the major metals accumulated by oysters to phenomenally high concentrations (more than 3.0% of Zn and about 2.0% of Cu against what the dry weight of tissues were accumulated), and Cr, Ni, Mn, etc were also significantly accumulated. The differentially expressed proteins in the gills of oysters exposed to heavy metals participate in several cell processes, such as metal binding, transporting and saving, oxidative-reduction balance maintaining, stress response, signal transduction, etc. Significantly up-regulated expression (about 10 folds) of an important metal binding protein, metallothionein (MT) and granular cells was observed in the gills of oysters exposed to long-term and severely heavy-metal-contaminated estuary, it suggested that binding toxic metals with metallothionein-like proteins (MTLP) and storing toxic metals in metal-rich granules (MRG) with insoluble forms were the important strategies of oyster to detoxify the toxic metals and adapt to the high level of metal-contaminated environment. Most of the stress and immunity responsive proteins, such as heat shock proteins (HSP), extracellular superoxide dismutase (ECSOD) and cavortin, and the cellular redox reaction relative proteins such as 20G-Fe (II) oxygenase family oxidoreductase, aldehyde dehydrogenase and retinal dehydrogenase 2, were detected significantly down-regulated in the gills of oysters exposed to long term heavy metal contaminated environments, it indicated that long term exposure different from emergent exposure to heavy metal contamination may significantly suppress the stress and immunity response system of oysters. Moreover, Formin homology 2 domain containing protein (FH2). The only protein domain to directly nucleate actin monomers into unbranched filament polymers, by which will subsequently control gene expression and chromatin remodelling complexes, was also detected greatly up-regulated in the gills of oysters exposed to long-term heavy metal contaminations. It indicated that nuclear activity regulation may also be important for oyster to adapt to the long-term heavy-metal-contaminated environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experimental investigation of MRgHIFU sonication with interleaved electronic and mechanical displacement of the focal point for transrectal prostate application

NASA Astrophysics Data System (ADS)

Petrusca, Lorena; Ngo, Jacqueline; Brasset, Lucie; Blanc, Emmanuel; Murillo, Adriana; Auboiroux, Vincent; Cotton, François; Chapelon, Jean-Yves; Salomir, Rares

2012-08-01

High intensity focused ultrasound (HIFU) under MRI guidance may provide minimally invasive treatment for localized prostate cancer. In this study, ex vivo and in vivo experiments were performed using a prostate-dedicated endorectal phased array (16 circular elements arranged on a truncated spherical cap of radius 60 mm) and a translation-rotation mechanical actuator in order to evaluate the lesion formation and the potential interest of dual-modality (electronic and mechanical) interleaved displacement of the focus for volumetric sonication paradigms. Different sonication sequences, including elementary lesions, line scan, slice sweeping and volume sonications, were investigated with a clinical 1.5 T MR scanner. Two orthogonal planes (axial and sagittal) were simultaneously monitored using rapid MR thermometry (PRFS method) and the temperature and thermal dose maps were displayed in real time. No RF interferences were detected in MR acquisition during sonications. The shape of the thermal lesions in vivo was examined at day 5 post-treatment by MRI follow-up (T2w sequence and Gd-T1w-TFE) and postmortem histological analysis. This study suggests that electronic displacement of the focus (along the ultrasound propagation axis) interleaved with mechanical X-Z translations and rotation around B0 can be a suitable modality to treat patient-specific sizes and shapes of a pathologic tissue. The electronic displacement of focus (achieved in less than 0.1 s) is an order of magnitude faster than the mechanical motion of the HIFU device (1 s latency). As an example, for an in vivo volumetric sonication with foci between 32 and 47 mm (7 successive line scans, 11 lines/slice, 4 foci/line) with applied powers between 17.4 and 39.1 Wac, a total duration of sonication of 408.1 s was required to ablate a volume of approximately 5.7 cm3 (semi-chronic lesion measured at day 5), while the maximum temperature elevation reached was 30 °C. While electronic focusing is necessary to speed up the procedure, one should consider as a potential drawback the non-negligible risk for generating secondary lobes with full steering in 3D. Reference-free PRFS thermometry accurately removed the effects of Bo dynamic perturbation in the vicinity of the moving transducer. Therefore, the dual-modality volumetric sonication paradigm represents a cost-effective technological compromise to induce the desired shape of the lesion in the prostate through the limited endorectal space, in a reasonable period of time and without side effects.

Experimental investigation of MRgHIFU sonication with interleaved electronic and mechanical displacement of the focal point for transrectal prostate application.

PubMed

Petrusca, Lorena; Ngo, Jacqueline; Brasset, Lucie; Blanc, Emmanuel; Murillo, Adriana; Auboiroux, Vincent; Cotton, François; Chapelon, Jean-Yves; Salomir, Rares

2012-08-07

High intensity focused ultrasound (HIFU) under MRI guidance may provide minimally invasive treatment for localized prostate cancer. In this study, ex vivo and in vivo experiments were performed using a prostate-dedicated endorectal phased array (16 circular elements arranged on a truncated spherical cap of radius 60 mm) and a translation-rotation mechanical actuator in order to evaluate the lesion formation and the potential interest of dual-modality (electronic and mechanical) interleaved displacement of the focus for volumetric sonication paradigms. Different sonication sequences, including elementary lesions, line scan, slice sweeping and volume sonications, were investigated with a clinical 1.5 T MR scanner. Two orthogonal planes (axial and sagittal) were simultaneously monitored using rapid MR thermometry (PRFS method) and the temperature and thermal dose maps were displayed in real time. No RF interferences were detected in MR acquisition during sonications. The shape of the thermal lesions in vivo was examined at day 5 post-treatment by MRI follow-up (T2w sequence and Gd-T1w-TFE) and postmortem histological analysis. This study suggests that electronic displacement of the focus (along the ultrasound propagation axis) interleaved with mechanical X-Z translations and rotation around B(0) can be a suitable modality to treat patient-specific sizes and shapes of a pathologic tissue. The electronic displacement of focus (achieved in less than 0.1 s) is an order of magnitude faster than the mechanical motion of the HIFU device (1 s latency). As an example, for an in vivo volumetric sonication with foci between 32 and 47 mm (7 successive line scans, 11 lines/slice, 4 foci/line) with applied powers between 17.4 and 39.1 Wac, a total duration of sonication of 408.1 s was required to ablate a volume of approximately 5.7 cm(3) (semi-chronic lesion measured at day 5), while the maximum temperature elevation reached was 30 °C. While electronic focusing is necessary to speed up the procedure, one should consider as a potential drawback the non-negligible risk for generating secondary lobes with full steering in 3D. Reference-free PRFS thermometry accurately removed the effects of B(o) dynamic perturbation in the vicinity of the moving transducer. Therefore, the dual-modality volumetric sonication paradigm represents a cost-effective technological compromise to induce the desired shape of the lesion in the prostate through the limited endorectal space, in a reasonable period of time and without side effects.

Prediction of metastable metal-rare gas fluorides: FMRgF (M =Be and Mg; Rg =Ar, Kr and Xe)

NASA Astrophysics Data System (ADS)

Jayasekharan, T.; Ghanty, T. K.

2008-04-01

The structure, stability, charge redistribution, bonding, and harmonic vibrational frequencies of rare gas containing group II-A fluorides with the general formula FMRgF (where M =Be and Mg; Rg =Ar, Kr, and Xe) have been investigated using second order Møller-Plesset perturbation theory, density functional theory, and coupled cluster theory [CCSD(T)] methods. The species, FMRgF show a quasilinear structure at the minima and a bent structure at the transition state. The predicted species are unstable with respect to the two-body dissociation channel, leading to the global minima (MF2+Rg) on the singlet potential energy surface. However, with respect to other two-body dissociation channel (FM+RgF), they are found to be stable and have high positive energies on the same surface. The computed binding energy for the two-body dissociation channels are 94.0, 164.7, and 199.7kJmol-1 for FBeArF, FBeKrF, FBeXeF, respectively, at CCSD(T) method. The corresponding energy values are 83.4, 130.7, and 180.1kJmol-1 for FMgArF, FMgKrF, and FMgXeF, respectively, at the same level of theory. With respect to the three-body dissociation (FM+Rg+F) channel as well as dissociation into atomic constituent, they are also found to be stable and have high positive energies. The dissociation of the predicted species typically proceeds via MRgF bending mode at the transition state. The computed barrier heights for the transition states are 11.4, 32.2, and 57.6kJmol-1 for FBeArF, FBeKrF, and FBeXeF, respectively, at the CCSD(T) method. The corresponding barrier heights for the Mg containing species are 2.1, 9.2, and 32.1kJmol-1 along the series Ar KrXe, respectively. The M Rg bond energies of the FMRgF species is significantly higher than the corresponding bond energies of the M+Rg species (˜53 and ˜15kJmol-1 for Be+Ar and Mg+Ar, respectively). The computed energy diagram as well as the geometrical parameters along with the AIM results suggest that the species are metastable with partial covalent character in the M Rg bonding. Thus, it may be possible to prepare and to characterize these species using low temperature matrix isolation technique.

[Comparison of the present and previously used protocol of risk stratification in children with acute lymphoblastic leukemia].

PubMed

Glodkowska, Eliza; Bialas, Agnieszka; Jackowska, Teresa

2007-01-01

Acute lymphoblastic leukaemia (ALL) is one of the most common cancers in children. In Poland, since November 2002 a new protocol of risk stratification has been recommended for assessment of risk factors and for choosing therapy regimens. assessment of accuracy of protocol ALL-IC 2002 in comparison to previously used risk stratification protocols. ALL was diagnosed in 100 children (44 girls, 56 boys; 1-18 years of age) in the Department of Pediatric Hematology and Oncology, Warsaw Medical University, over the period from November 2002 to November 2006. According to the ALL-IC 2002 protocol the patients were divided into three risk groups: SR-standard, IR-intermediate and HR-high. The stratification was by age, leukocyte count, cytogenetic changes, early response to prednisone therapy and bone marrow remission. In the previously used risk stratification protocols-BFM-90, only hepatosplenomegaly and the number of blasts in peripheral blood (PB) were considered, and the patients were divided into three risk groups: low (LRG<0.8), medium (MRG) and high (HRG>1.2). out of the 100 patients qualified for treatment regimens according to the ALL-IC 2002 protocol, 97 entered remission, 11 died and 3 had a relapse. Under the ALL-IC 2002 protocol these children were stratified into the following groups: SR-31%, IR-44% and HR-25%. In the previously used stratification, there would be 26% children in low, 46% in the medium and 28% in the high risk group. According to the BFM-90 protocol 18/31 (58%) and 16/44 (36%) patients from the SR and IR groups respectively would be given more intensive treatment. On the other hand 11/44 (25%) and 14/25 (56%) patients from the IR and HR groups respectively would be given less intensive treatment. 1. ALL-IC 2002 protocol in comparison with the previously used protocol BFM-90, changes the qualification of children with ALL for the SR, IR and HR risk groups. This is linked to basic change of treatment protocol, adequate to severity of disease. 2. Children with ALL qualified according to protocol BFM-90 for moderate risk group (IR) constitute a mixed group in the ALL-IC 2002 classification. Part of the children was moved to the standard risk group (SR), part to high risk group (HR), and the rest remains in the intermediate risk category (IR). 3. Further studies are needed on stratification validity according to ALL-IL 2002 and on the need of further modification (eg assessment of additional factors) in order to decide on the best treatment, adequate to severity of disease.

Sampling strategies for subsampled segmented EPI PRF thermometry in MR guided high intensity focused ultrasound

PubMed Central

Odéen, Henrik; Todd, Nick; Diakite, Mahamadou; Minalga, Emilee; Payne, Allison; Parker, Dennis L.

2014-01-01

Purpose: To investigate k-space subsampling strategies to achieve fast, large field-of-view (FOV) temperature monitoring using segmented echo planar imaging (EPI) proton resonance frequency shift thermometry for MR guided high intensity focused ultrasound (MRgHIFU) applications. Methods: Five different k-space sampling approaches were investigated, varying sample spacing (equally vs nonequally spaced within the echo train), sampling density (variable sampling density in zero, one, and two dimensions), and utilizing sequential or centric sampling. Three of the schemes utilized sequential sampling with the sampling density varied in zero, one, and two dimensions, to investigate sampling the k-space center more frequently. Two of the schemes utilized centric sampling to acquire the k-space center with a longer echo time for improved phase measurements, and vary the sampling density in zero and two dimensions, respectively. Phantom experiments and a theoretical point spread function analysis were performed to investigate their performance. Variable density sampling in zero and two dimensions was also implemented in a non-EPI GRE pulse sequence for comparison. All subsampled data were reconstructed with a previously described temporally constrained reconstruction (TCR) algorithm. Results: The accuracy of each sampling strategy in measuring the temperature rise in the HIFU focal spot was measured in terms of the root-mean-square-error (RMSE) compared to fully sampled “truth.” For the schemes utilizing sequential sampling, the accuracy was found to improve with the dimensionality of the variable density sampling, giving values of 0.65 °C, 0.49 °C, and 0.35 °C for density variation in zero, one, and two dimensions, respectively. The schemes utilizing centric sampling were found to underestimate the temperature rise, with RMSE values of 1.05 °C and 1.31 °C, for variable density sampling in zero and two dimensions, respectively. Similar subsampling schemes with variable density sampling implemented in zero and two dimensions in a non-EPI GRE pulse sequence both resulted in accurate temperature measurements (RMSE of 0.70 °C and 0.63 °C, respectively). With sequential sampling in the described EPI implementation, temperature monitoring over a 192 × 144 × 135 mm3 FOV with a temporal resolution of 3.6 s was achieved, while keeping the RMSE compared to fully sampled “truth” below 0.35 °C. Conclusions: When segmented EPI readouts are used in conjunction with k-space subsampling for MR thermometry applications, sampling schemes with sequential sampling, with or without variable density sampling, obtain accurate phase and temperature measurements when using a TCR reconstruction algorithm. Improved temperature measurement accuracy can be achieved with variable density sampling. Centric sampling leads to phase bias, resulting in temperature underestimations. PMID:25186406

Treatment of localized abscesses induced by methicillin-resistant Staphylococcus aureus (MRSA) using MRgFUS: First in vivo results

NASA Astrophysics Data System (ADS)

Rieck, Birgit; Curiel, Laura; Mougenot, Charles; Zhang, Kunyan; Pichardo, Samuel

2012-11-01

Background. In the present work we study the therapeutic effect of focused ultrasound on localized abscess induced by methicillin-resistant Staphylococcus aureus (MRSA). MRSA is a major nosocomial pathogen in health-care facilities. The people, particularly those who are immunocompromised are prone to develop infectious sites that often are non-responsive to regular treatments. Because of its capability to induce a rise of temperature at a very precise location, the use of focused ultrasound represents a considerable opportunity to propose a new therapy for MRSA-related infections. Methods. A 50μL subcutaneous injection of MRSA strain USA 400 bacteria at a concentration of 7×103/μL was made on the left thigh of BALB/c mice and an abscess of 6±2 mm-length formed after 48hrs. A transducer operating at 3 MHz with a focal length of 50mm and diameter of 32mm was used to treat the abscess. The focal point was positioned 2mm under the skin at the abscess center. Forty-eight hours after injection 4 ultrasound exposures of 9s-each were applied to each abscess under Magnetic Resonance-guidance. Each exposure was followed by a 1 min pause. Real-time estimation of change of temperature was done using a communication toolbox (matMRI) developed in our laboratory. Three experimental groups of 6 animals each were tested: moderate temperature (MT), high temperature (HT) and control. MT and HT groups reached, respectively, 55°C and 65°C at end of exposure. Effectiveness of the treatment was assessed by culturing bacteria of the treated abscess 1 and 4 days after treatment. Spleen samples were cultured to test for septicemia. Results. Macroscopic evaluation of treated abscess indicated a diminution of external size of abscess 1d after treatment. Treatment did not cause open wounds. Bacteria counting 1 day after treatment was 0.7±1.1 × 105, 0.5±0.7 × 105 and 1.1±2.3 × 105 CFU/μl for MT, HT and control groups, respectively; for the 4-day end point, the count was 0.6±0.6 × 104, 0.09±0.2×104 and 1.0±1.3 × 104. Absence of bacteria in spleen samples indicated that the therapy did not trigger septicemia. Conclusions. Focused ultrasound induces a therapeutic effect in abscesses induced by MRSA. This effect is observed as a reduction of the number bacteria in the abscess. These initial results indicate that focused ultrasound is a viable option for the treatment of MRSA-related infections.

Sampling strategies for subsampled segmented EPI PRF thermometry in MR guided high intensity focused ultrasound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Odéen, Henrik, E-mail: h.odeen@gmail.com; Diakite, Mahamadou; Todd, Nick

2014-09-15

Purpose: To investigate k-space subsampling strategies to achieve fast, large field-of-view (FOV) temperature monitoring using segmented echo planar imaging (EPI) proton resonance frequency shift thermometry for MR guided high intensity focused ultrasound (MRgHIFU) applications. Methods: Five different k-space sampling approaches were investigated, varying sample spacing (equally vs nonequally spaced within the echo train), sampling density (variable sampling density in zero, one, and two dimensions), and utilizing sequential or centric sampling. Three of the schemes utilized sequential sampling with the sampling density varied in zero, one, and two dimensions, to investigate sampling the k-space center more frequently. Two of the schemesmore » utilized centric sampling to acquire the k-space center with a longer echo time for improved phase measurements, and vary the sampling density in zero and two dimensions, respectively. Phantom experiments and a theoretical point spread function analysis were performed to investigate their performance. Variable density sampling in zero and two dimensions was also implemented in a non-EPI GRE pulse sequence for comparison. All subsampled data were reconstructed with a previously described temporally constrained reconstruction (TCR) algorithm. Results: The accuracy of each sampling strategy in measuring the temperature rise in the HIFU focal spot was measured in terms of the root-mean-square-error (RMSE) compared to fully sampled “truth.” For the schemes utilizing sequential sampling, the accuracy was found to improve with the dimensionality of the variable density sampling, giving values of 0.65 °C, 0.49 °C, and 0.35 °C for density variation in zero, one, and two dimensions, respectively. The schemes utilizing centric sampling were found to underestimate the temperature rise, with RMSE values of 1.05 °C and 1.31 °C, for variable density sampling in zero and two dimensions, respectively. Similar subsampling schemes with variable density sampling implemented in zero and two dimensions in a non-EPI GRE pulse sequence both resulted in accurate temperature measurements (RMSE of 0.70 °C and 0.63 °C, respectively). With sequential sampling in the described EPI implementation, temperature monitoring over a 192 × 144 × 135 mm{sup 3} FOV with a temporal resolution of 3.6 s was achieved, while keeping the RMSE compared to fully sampled “truth” below 0.35 °C. Conclusions: When segmented EPI readouts are used in conjunction with k-space subsampling for MR thermometry applications, sampling schemes with sequential sampling, with or without variable density sampling, obtain accurate phase and temperature measurements when using a TCR reconstruction algorithm. Improved temperature measurement accuracy can be achieved with variable density sampling. Centric sampling leads to phase bias, resulting in temperature underestimations.« less

North-south comparison of springtime dark slope structures on Mars, and the possibility of liquid water

NASA Astrophysics Data System (ADS)

Kereszturi, A.; Berczi, Sz.; Horvath, A.; Ganti, T.; Kuti, A.; Pocs, T.; Sik, A.; Szathmary, E.

2008-09-01

Introduction Various polar seasonal surface albedo structures were analyzed by several authors in the past [1, 2, 3, 4, 5, 6, 7, 8, 8, 9], partly in connection with the possibility of liquid water. In our previous work [10] we identified two groups of slope streaks emanating form Dark Dune Spots of polar dunes, which grow in size and number during spring with the advancement of the season. The diffuse shaped group appears earlier and formed probably by CO2 geysers [8]. The confine shaped group appears in a later seasonal phase, when the temperature is higher. They are probably connected with exposed water-ice on the surface, and may formed by the seepage of undercooled interfacial water on microscopic scale [11]. Methods For the analysis of northern slope structures we used MGS MOC, MRO HiRISE images, and MRG TES data [12] using the "vanilla" software. Temperature data show annual trend, and were derived for daytime. Note that the surface temperature values have spatial resolution around 3 km, and they can be taken only as a rough approach of the surface temperature of the whole dune complex, and not different parts of it. Discussion The target area of the analysis was (84N 233E) in the northern circumpolar sand sea, with 300-500 m diameter overlapping dunes. We searched for springtime confined and elongated dark slope streaks, similar to those, which we observed at south. Basic similarities between northern and southern structures are: 1. streaks always emanate from Dark Dune Spots in downward direction, 2. streaks are present in local spring, when the temperature is above the CO2 buffered level, suggesting there are parts of the surface without CO2 ice, where possibly H2O ice is exposed (Fig. 1.), 4. the streaks show branching pattern (Fig. 2.). Basic differences between the northern and southern structures: 1. at north there is a dark annulus around the Dark Dune Spots, which is absent at south, 2. there are fewer and fainter diffuse streaks of gas jet activity at north, 3. there are fewer pond-like accumulated structures at the streaks' end at north. Conclusion The branching dark pattern suggests the movement of liquid-like material, while the temperature data suggest these dark features are formed possibly in connection with H2O ice. The moving material may be composed of dry or adsorbed water [13] lubricated grains also. Based on the probably presence of waterice, and the model of adsorbed water, northern DDSslope structures may be the result of seepage by interfacial water around solar heated dune grains, as well as the southern ones. This situation may have astrobiological consequences [14] too. Acknowledgment This work was supported by the ESA ECS-project No. 98004 and the Pro Renovanda Cultura Hungariae Foundation. References [1] Kieffer H. et al. (2000) 2nd Conf. Mars Pol. Sci. 93., [2] Ness & Orme JBIS (2002) 55, 85-109. [3] Piqueux S. et al. (2003) JGR 108, 5084. [4] Christensen et al. (2005) AGU, Fall Meeting #P23C- 04. [5] Malin M.C. et al., (1998) Science 279, 1681-1685. [6] Malin M.C. and Edgett K.S. (2000) XXXIth LPSC #1056. [7] Zuber T.M. (2003) Science 302, 1694-1695. [8] Kieffer H.H. et al.

Transforming Collaborative Process Models into Interface Process Models by Applying an MDA Approach

NASA Astrophysics Data System (ADS)

Lazarte, Ivanna M.; Chiotti, Omar; Villarreal, Pablo D.

Collaborative business models among enterprises require defining collaborative business processes. Enterprises implement B2B collaborations to execute these processes. In B2B collaborations the integration and interoperability of processes and systems of the enterprises are required to support the execution of collaborative processes. From a collaborative process model, which describes the global view of the enterprise interactions, each enterprise must define the interface process that represents the role it performs in the collaborative process in order to implement the process in a Business Process Management System. Hence, in this work we propose a method for the automatic generation of the interface process model of each enterprise from a collaborative process model. This method is based on a Model-Driven Architecture to transform collaborative process models into interface process models. By applying this method, interface processes are guaranteed to be interoperable and defined according to a collaborative process.

Extensible packet processing architecture

DOEpatents

Robertson, Perry J.; Hamlet, Jason R.; Pierson, Lyndon G.; Olsberg, Ronald R.; Chun, Guy D.

2013-08-20

A technique for distributed packet processing includes sequentially passing packets associated with packet flows between a plurality of processing engines along a flow through data bus linking the plurality of processing engines in series. At least one packet within a given packet flow is marked by a given processing engine to signify by the given processing engine to the other processing engines that the given processing engine has claimed the given packet flow for processing. A processing function is applied to each of the packet flows within the processing engines and the processed packets are output on a time-shared, arbitered data bus coupled to the plurality of processing engines.

Processed and ultra-processed foods are associated with lower-quality nutrient profiles in children from Colombia.

PubMed

Cornwell, Brittany; Villamor, Eduardo; Mora-Plazas, Mercedes; Marin, Constanza; Monteiro, Carlos A; Baylin, Ana

2018-01-01

To determine if processed and ultra-processed foods consumed by children in Colombia are associated with lower-quality nutrition profiles than less processed foods. We obtained information on sociodemographic and anthropometric variables and dietary information through dietary records and 24 h recalls from a convenience sample of the Bogotá School Children Cohort. Foods were classified into three categories: (i) unprocessed and minimally processed foods, (ii) processed culinary ingredients and (iii) processed and ultra-processed foods. We also examined the combination of unprocessed foods and processed culinary ingredients. Representative sample of children from low- to middle-income families in Bogotá, Colombia. Children aged 5-12 years in 2011 Bogotá School Children Cohort. We found that processed and ultra-processed foods are of lower dietary quality in general. Nutrients that were lower in processed and ultra-processed foods following adjustment for total energy intake included: n-3 PUFA, vitamins A, B12, C and E, Ca and Zn. Nutrients that were higher in energy-adjusted processed and ultra-processed foods compared with unprocessed foods included: Na, sugar and trans-fatty acids, although we also found that some healthy nutrients, including folate and Fe, were higher in processed and ultra-processed foods compared with unprocessed and minimally processed foods. Processed and ultra-processed foods generally have unhealthy nutrition profiles. Our findings suggest the categorization of foods based on processing characteristics is promising for understanding the influence of food processing on children's dietary quality. More studies accounting for the type and degree of food processing are needed.

Dynamic control of remelting processes

DOEpatents

Bertram, Lee A.; Williamson, Rodney L.; Melgaard, David K.; Beaman, Joseph J.; Evans, David G.

2000-01-01

An apparatus and method of controlling a remelting process by providing measured process variable values to a process controller; estimating process variable values using a process model of a remelting process; and outputting estimated process variable values from the process controller. Feedback and feedforward control devices receive the estimated process variable values and adjust inputs to the remelting process. Electrode weight, electrode mass, electrode gap, process current, process voltage, electrode position, electrode temperature, electrode thermal boundary layer thickness, electrode velocity, electrode acceleration, slag temperature, melting efficiency, cooling water temperature, cooling water flow rate, crucible temperature profile, slag skin temperature, and/or drip short events are employed, as are parameters representing physical constraints of electroslag remelting or vacuum arc remelting, as applicable.

On Intelligent Design and Planning Method of Process Route Based on Gun Breech Machining Process

NASA Astrophysics Data System (ADS)

Hongzhi, Zhao; Jian, Zhang

2018-03-01

The paper states an approach of intelligent design and planning of process route based on gun breech machining process, against several problems, such as complex machining process of gun breech, tedious route design and long period of its traditional unmanageable process route. Based on gun breech machining process, intelligent design and planning system of process route are developed by virtue of DEST and VC++. The system includes two functional modules--process route intelligent design and its planning. The process route intelligent design module, through the analysis of gun breech machining process, summarizes breech process knowledge so as to complete the design of knowledge base and inference engine. And then gun breech process route intelligently output. On the basis of intelligent route design module, the final process route is made, edited and managed in the process route planning module.

Gasoline from coal in the state of Illinois: feasibility study. Volume I. Design. [KBW gasification process, ICI low-pressure methanol process and Mobil M-gasoline process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-01-01

Volume 1 describes the proposed plant: KBW gasification process, ICI low-pressure methanol process and Mobil M-gasoline process, and also with ancillary processes, such as oxygen plant, shift process, RECTISOL purification process, sulfur recovery equipment and pollution control equipment. Numerous engineering diagrams are included. (LTN)

Performing a local reduction operation on a parallel computer

DOEpatents

Blocksome, Michael A; Faraj, Daniel A

2013-06-04

A parallel computer including compute nodes, each including two reduction processing cores, a network write processing core, and a network read processing core, each processing core assigned an input buffer. Copying, in interleaved chunks by the reduction processing cores, contents of the reduction processing cores' input buffers to an interleaved buffer in shared memory; copying, by one of the reduction processing cores, contents of the network write processing core's input buffer to shared memory; copying, by another of the reduction processing cores, contents of the network read processing core's input buffer to shared memory; and locally reducing in parallel by the reduction processing cores: the contents of the reduction processing core's input buffer; every other interleaved chunk of the interleaved buffer; the copied contents of the network write processing core's input buffer; and the copied contents of the network read processing core's input buffer.

Performing a local reduction operation on a parallel computer

DOEpatents

Blocksome, Michael A.; Faraj, Daniel A.

2012-12-11

A parallel computer including compute nodes, each including two reduction processing cores, a network write processing core, and a network read processing core, each processing core assigned an input buffer. Copying, in interleaved chunks by the reduction processing cores, contents of the reduction processing cores' input buffers to an interleaved buffer in shared memory; copying, by one of the reduction processing cores, contents of the network write processing core's input buffer to shared memory; copying, by another of the reduction processing cores, contents of the network read processing core's input buffer to shared memory; and locally reducing in parallel by the reduction processing cores: the contents of the reduction processing core's input buffer; every other interleaved chunk of the interleaved buffer; the copied contents of the network write processing core's input buffer; and the copied contents of the network read processing core's input buffer.

Situation awareness acquired from monitoring process plants - the Process Overview concept and measure.

PubMed

Lau, Nathan; Jamieson, Greg A; Skraaning, Gyrd

2016-07-01

We introduce Process Overview, a situation awareness characterisation of the knowledge derived from monitoring process plants. Process Overview is based on observational studies of process control work in the literature. The characterisation is applied to develop a query-based measure called the Process Overview Measure. The goal of the measure is to improve coupling between situation and awareness according to process plant properties and operator cognitive work. A companion article presents the empirical evaluation of the Process Overview Measure in a realistic process control setting. The Process Overview Measure demonstrated sensitivity and validity by revealing significant effects of experimental manipulations that corroborated with other empirical results. The measure also demonstrated adequate inter-rater reliability and practicality for measuring SA based on data collected by process experts. Practitioner Summary: The Process Overview Measure is a query-based measure for assessing operator situation awareness from monitoring process plants in representative settings.

43 CFR 2804.19 - How will BLM process my Processing Category 6 application?

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false How will BLM process my Processing... process my Processing Category 6 application? (a) For Processing Category 6 applications, you and BLM must enter into a written agreement that describes how BLM will process your application. The final agreement...

43 CFR 2804.19 - How will BLM process my Processing Category 6 application?

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false How will BLM process my Processing... process my Processing Category 6 application? (a) For Processing Category 6 applications, you and BLM must enter into a written agreement that describes how BLM will process your application. The final agreement...

Process Correlation Analysis Model for Process Improvement Identification

PubMed Central

Park, Sooyong

2014-01-01

Software process improvement aims at improving the development process of software systems. It is initiated by process assessment identifying strengths and weaknesses and based on the findings, improvement plans are developed. In general, a process reference model (e.g., CMMI) is used throughout the process of software process improvement as the base. CMMI defines a set of process areas involved in software development and what to be carried out in process areas in terms of goals and practices. Process areas and their elements (goals and practices) are often correlated due to the iterative nature of software development process. However, in the current practice, correlations of process elements are often overlooked in the development of an improvement plan, which diminishes the efficiency of the plan. This is mainly attributed to significant efforts and the lack of required expertise. In this paper, we present a process correlation analysis model that helps identify correlations of process elements from the results of process assessment. This model is defined based on CMMI and empirical data of improvement practices. We evaluate the model using industrial data. PMID:24977170

Process correlation analysis model for process improvement identification.

PubMed

Choi, Su-jin; Kim, Dae-Kyoo; Park, Sooyong

2014-01-01

Software process improvement aims at improving the development process of software systems. It is initiated by process assessment identifying strengths and weaknesses and based on the findings, improvement plans are developed. In general, a process reference model (e.g., CMMI) is used throughout the process of software process improvement as the base. CMMI defines a set of process areas involved in software development and what to be carried out in process areas in terms of goals and practices. Process areas and their elements (goals and practices) are often correlated due to the iterative nature of software development process. However, in the current practice, correlations of process elements are often overlooked in the development of an improvement plan, which diminishes the efficiency of the plan. This is mainly attributed to significant efforts and the lack of required expertise. In this paper, we present a process correlation analysis model that helps identify correlations of process elements from the results of process assessment. This model is defined based on CMMI and empirical data of improvement practices. We evaluate the model using industrial data.

Cleanliness of Ti-bearing Al-killed ultra-low-carbon steel during different heating processes

NASA Astrophysics Data System (ADS)

Guo, Jian-long; Bao, Yan-ping; Wang, Min

2017-12-01

During the production of Ti-bearing Al-killed ultra-low-carbon (ULC) steel, two different heating processes were used when the converter tapping temperature or the molten steel temperature in the Ruhrstahl-Heraeus (RH) process was low: heating by Al addition during the RH decarburization process and final deoxidation at the end of the RH decarburization process (process-I), and increasing the oxygen content at the end of RH decarburization, heating and final deoxidation by one-time Al addition (process-II). Temperature increases of 10°C by different processes were studied; the results showed that the two heating processes could achieve the same heating effect. The T.[O] content in the slab and the refining process was better controlled by process-I than by process-II. Statistical analysis of inclusions showed that the numbers of inclusions in the slab obtained by process-I were substantially less than those in the slab obtained by process-II. For process-I, the Al2O3 inclusions produced by Al added to induce heating were substantially removed at the end of decarburization. The amounts of inclusions were substantially greater for process-II than for process-I at different refining stages because of the higher dissolved oxygen concentration in process-II. Industrial test results showed that process-I was more beneficial for improving the cleanliness of molten steel.

Application of agent-based system for bioprocess description and process improvement.

PubMed

Gao, Ying; Kipling, Katie; Glassey, Jarka; Willis, Mark; Montague, Gary; Zhou, Yuhong; Titchener-Hooker, Nigel J

2010-01-01

Modeling plays an important role in bioprocess development for design and scale-up. Predictive models can also be used in biopharmaceutical manufacturing to assist decision-making either to maintain process consistency or to identify optimal operating conditions. To predict the whole bioprocess performance, the strong interactions present in a processing sequence must be adequately modeled. Traditionally, bioprocess modeling considers process units separately, which makes it difficult to capture the interactions between units. In this work, a systematic framework is developed to analyze the bioprocesses based on a whole process understanding and considering the interactions between process operations. An agent-based approach is adopted to provide a flexible infrastructure for the necessary integration of process models. This enables the prediction of overall process behavior, which can then be applied during process development or once manufacturing has commenced, in both cases leading to the capacity for fast evaluation of process improvement options. The multi-agent system comprises a process knowledge base, process models, and a group of functional agents. In this system, agent components co-operate with each other in performing their tasks. These include the description of the whole process behavior, evaluating process operating conditions, monitoring of the operating processes, predicting critical process performance, and providing guidance to decision-making when coping with process deviations. During process development, the system can be used to evaluate the design space for process operation. During manufacture, the system can be applied to identify abnormal process operation events and then to provide suggestions as to how best to cope with the deviations. In all cases, the function of the system is to ensure an efficient manufacturing process. The implementation of the agent-based approach is illustrated via selected application scenarios, which demonstrate how such a framework may enable the better integration of process operations by providing a plant-wide process description to facilitate process improvement. Copyright 2009 American Institute of Chemical Engineers

Electricity from sunlight. [low cost silicon for solar cells

NASA Technical Reports Server (NTRS)

Yaws, C. L.; Miller, J. W.; Lutwack, R.; Hsu, G.

1978-01-01

The paper discusses a number of new unconventional processes proposed for the low-cost production of silicon for solar cells. Consideration is given to: (1) the Battelle process (Zn/SiCl4), (2) the Battelle process (SiI4), (3) the Silane process, (4) the Motorola process (SiF4/SiF2), (5) the Westinghouse process (Na/SiCl4), (6) the Dow Corning process (C/SiO2), (7) the AeroChem process (SiCl4/H atom), and the Stanford process (Na/SiF4). Preliminary results indicate that the conventional process and the SiI4 processes cannot meet the project goal of $10/kg by 1986. Preliminary cost evaluation results for the Zn/SiCl4 process are favorable.

Composing Models of Geographic Physical Processes

NASA Astrophysics Data System (ADS)

Hofer, Barbara; Frank, Andrew U.

Processes are central for geographic information science; yet geographic information systems (GIS) lack capabilities to represent process related information. A prerequisite to including processes in GIS software is a general method to describe geographic processes independently of application disciplines. This paper presents such a method, namely a process description language. The vocabulary of the process description language is derived formally from mathematical models. Physical processes in geography can be described in two equivalent languages: partial differential equations or partial difference equations, where the latter can be shown graphically and used as a method for application specialists to enter their process models. The vocabulary of the process description language comprises components for describing the general behavior of prototypical geographic physical processes. These process components can be composed by basic models of geographic physical processes, which is shown by means of an example.

Process-based tolerance assessment of connecting rod machining process

NASA Astrophysics Data System (ADS)

Sharma, G. V. S. S.; Rao, P. Srinivasa; Surendra Babu, B.

2016-06-01

Process tolerancing based on the process capability studies is the optimistic and pragmatic approach of determining the manufacturing process tolerances. On adopting the define-measure-analyze-improve-control approach, the process potential capability index ( C p) and the process performance capability index ( C pk) values of identified process characteristics of connecting rod machining process are achieved to be greater than the industry benchmark of 1.33, i.e., four sigma level. The tolerance chain diagram methodology is applied to the connecting rod in order to verify the manufacturing process tolerances at various operations of the connecting rod manufacturing process. This paper bridges the gap between the existing dimensional tolerances obtained via tolerance charting and process capability studies of the connecting rod component. Finally, the process tolerancing comparison has been done by adopting a tolerance capability expert software.

Intranode data communications in a parallel computer

DOEpatents

Archer, Charles J; Blocksome, Michael A; Miller, Douglas R; Ratterman, Joseph D; Smith, Brian E

2014-01-07

Intranode data communications in a parallel computer that includes compute nodes configured to execute processes, where the data communications include: allocating, upon initialization of a first process of a computer node, a region of shared memory; establishing, by the first process, a predefined number of message buffers, each message buffer associated with a process to be initialized on the compute node; sending, to a second process on the same compute node, a data communications message without determining whether the second process has been initialized, including storing the data communications message in the message buffer of the second process; and upon initialization of the second process: retrieving, by the second process, a pointer to the second process's message buffer; and retrieving, by the second process from the second process's message buffer in dependence upon the pointer, the data communications message sent by the first process.

Intranode data communications in a parallel computer

DOEpatents

Archer, Charles J; Blocksome, Michael A; Miller, Douglas R; Ratterman, Joseph D; Smith, Brian E

2013-07-23

Intranode data communications in a parallel computer that includes compute nodes configured to execute processes, where the data communications include: allocating, upon initialization of a first process of a compute node, a region of shared memory; establishing, by the first process, a predefined number of message buffers, each message buffer associated with a process to be initialized on the compute node; sending, to a second process on the same compute node, a data communications message without determining whether the second process has been initialized, including storing the data communications message in the message buffer of the second process; and upon initialization of the second process: retrieving, by the second process, a pointer to the second process's message buffer; and retrieving, by the second process from the second process's message buffer in dependence upon the pointer, the data communications message sent by the first process.

Canadian Libraries and Mass Deacidification.

ERIC Educational Resources Information Center

Pacey, Antony

1992-01-01

Considers the advantages and disadvantages of six mass deacidification processes that libraries can use to salvage printed materials: the Wei T'o process, the Diethyl Zinc (DEZ) process, the FMC (Lithco) process, the Book Preservation Associates (BPA) process, the "Bookkeeper" process, and the "Lyophilization" process. The…

A new process sensitivity index to identify important system processes under process model and parametric uncertainty

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Heng; Ye, Ming; Walker, Anthony P.

Hydrological models are always composed of multiple components that represent processes key to intended model applications. When a process can be simulated by multiple conceptual-mathematical models (process models), model uncertainty in representing the process arises. While global sensitivity analysis methods have been widely used for identifying important processes in hydrologic modeling, the existing methods consider only parametric uncertainty but ignore the model uncertainty for process representation. To address this problem, this study develops a new method to probe multimodel process sensitivity by integrating the model averaging methods into the framework of variance-based global sensitivity analysis, given that the model averagingmore » methods quantify both parametric and model uncertainty. A new process sensitivity index is derived as a metric of relative process importance, and the index includes variance in model outputs caused by uncertainty in both process models and model parameters. For demonstration, the new index is used to evaluate the processes of recharge and geology in a synthetic study of groundwater reactive transport modeling. The recharge process is simulated by two models that converting precipitation to recharge, and the geology process is also simulated by two models of different parameterizations of hydraulic conductivity; each process model has its own random parameters. The new process sensitivity index is mathematically general, and can be applied to a wide range of problems in hydrology and beyond.« less

Depth-of-processing effects on priming in stem completion: tests of the voluntary-contamination, conceptual-processing, and lexical-processing hypotheses.

PubMed

Richardson-Klavehn, A; Gardiner, J M

1998-05-01

Depth-of-processing effects on incidental perceptual memory tests could reflect (a) contamination by voluntary retrieval, (b) sensitivity of involuntary retrieval to prior conceptual processing, or (c) a deficit in lexical processing during graphemic study tasks that affects involuntary retrieval. The authors devised an extension of incidental test methodology--making conjunctive predictions about response times as well as response proportions--to discriminate among these alternatives. They used graphemic, phonemic, and semantic study tasks, and a word-stem completion test with incidental, intentional, and inclusion instructions. Semantic study processing was superior to phonemic study processing in the intentional and inclusion tests, but semantic and phonemic study processing produced equal priming in the incidental test, showing that priming was uncontaminated by voluntary retrieval--a conclusion reinforced by the response-time data--and that priming was insensitive to prior conceptual processing. The incidental test nevertheless showed a priming deficit following graphemic study processing, supporting the lexical-processing hypothesis. Adding a lexical decision to the 3 study tasks eliminated the priming deficit following graphemic study processing, but did not influence priming following phonemic and semantic processing. The results provide the first clear evidence that depth-of-processing effects on perceptual priming can reflect lexical processes, rather than voluntary contamination or conceptual processes.

Improving operational anodising process performance using simulation approach

NASA Astrophysics Data System (ADS)

Liong, Choong-Yeun; Ghazali, Syarah Syahidah

2015-10-01

The use of aluminium is very widespread, especially in transportation, electrical and electronics, architectural, automotive and engineering applications sectors. Therefore, the anodizing process is an important process for aluminium in order to make the aluminium durable, attractive and weather resistant. This research is focused on the anodizing process operations in manufacturing and supplying of aluminium extrusion. The data required for the development of the model is collected from the observations and interviews conducted in the study. To study the current system, the processes involved in the anodizing process are modeled by using Arena 14.5 simulation software. Those processes consist of five main processes, namely the degreasing process, the etching process, the desmut process, the anodizing process, the sealing process and 16 other processes. The results obtained were analyzed to identify the problems or bottlenecks that occurred and to propose improvement methods that can be implemented on the original model. Based on the comparisons that have been done between the improvement methods, the productivity could be increased by reallocating the workers and reducing loading time.

Value-driven process management: using value to improve processes.

PubMed

Melnyk, S A; Christensen, R T

2000-08-01

Every firm can be viewed as consisting of various processes. These processes affect everything that the firm does from accepting orders and designing products to scheduling production. In many firms, the management of processes often reflects considerations of efficiency (cost) rather than effectiveness (value). In this article, we introduce a well-structured process for managing processes that begins not with the process, but rather with the customer and the product and the concept of value. This process progresses through a number of steps which include issues such as defining value, generating the appropriate metrics, identifying the critical processes, mapping and assessing the performance of these processes, and identifying long- and short-term areas for action. What makes the approach presented in this article so powerful is that it explicitly links the customer to the process and that the process is evaluated in term of its ability to effectively serve the customers.

Method for routing events from key strokes in a multi-processing computer systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rhodes, D.A.; Rustici, E.; Carter, K.H.

1990-01-23

The patent describes a method of routing user input in a computer system which concurrently runs a plurality of processes. It comprises: generating keycodes representative of keys typed by a user; distinguishing generated keycodes by looking up each keycode in a routing table which assigns each possible keycode to an individual assigned process of the plurality of processes, one of which processes being a supervisory process; then, sending each keycode to its assigned process until a keycode assigned to the supervisory process is received; sending keycodes received subsequent to the keycode assigned to the supervisory process to a buffer; next,more » providing additional keycodes to the supervisory process from the buffer until the supervisory process has completed operation; and sending keycodes stored in the buffer to processes assigned therewith after the supervisory process has completedoperation.« less

Issues Management Process Course # 38401

DOE Office of Scientific and Technical Information (OSTI.GOV)

Binion, Ula Marie

The purpose of this training it to advise Issues Management Coordinators (IMCs) on the revised Contractor Assurance System (CAS) Issues Management (IM) process. Terminal Objectives: Understand the Laboratory’s IM process; Understand your role in the Laboratory’s IM process. Learning Objectives: Describe the IM process within the context of the CAS; Describe the importance of implementing an institutional IM process at LANL; Describe the process flow for the Laboratory’s IM process; Apply the definition of an issue; Use available resources to determine initial screening risk levels for issues; Describe the required major process steps for each risk level; Describe the personnelmore » responsibilities for IM process implementation; Access available resources to support IM process implementation.« less

Social network supported process recommender system.

PubMed

Ye, Yanming; Yin, Jianwei; Xu, Yueshen

2014-01-01

Process recommendation technologies have gained more and more attention in the field of intelligent business process modeling to assist the process modeling. However, most of the existing technologies only use the process structure analysis and do not take the social features of processes into account, while the process modeling is complex and comprehensive in most situations. This paper studies the feasibility of social network research technologies on process recommendation and builds a social network system of processes based on the features similarities. Then, three process matching degree measurements are presented and the system implementation is discussed subsequently. Finally, experimental evaluations and future works are introduced.

[Definition and stabilization of processes I. Management processes and support in a Urology Department].

PubMed

Pascual, Carlos; Luján, Marcos; Mora, José Ramón; Chiva, Vicente; Gamarra, Manuela

2015-01-01

The implantation of total quality management models in clinical departments can better adapt to the 2009 ISO 9004 model. An essential part of implantation of these models is the establishment of processes and their stabilization. There are four types of processes: key, management, support and operative (clinical). Management processes have four parts: process stabilization form, process procedures form, medical activities cost estimation form and, process flow chart. In this paper we will detail the creation of an essential process in a surgical department, such as the process of management of the surgery waiting list.

T-Check in Technologies for Interoperability: Business Process Management in a Web Services Context

DTIC Science & Technology

2008-09-01

UML Sequence Diagram) 6  Figure 3:   BPMN Diagram of the Order Processing Business Process 9  Figure 4:   T-Check Process for Technology Evaluation 10...Figure 5:  Notional System Architecture 12  Figure 6:  Flow Chart of the Order Processing Business Process 14  Figure 7:  Order Processing Activities...features. Figure 3 (created with Intalio BPMS Designer [Intalio 2008]) shows a BPMN view of the Order Processing business process that is used in the

A case study: application of statistical process control tool for determining process capability and sigma level.

PubMed

Chopra, Vikram; Bairagi, Mukesh; Trivedi, P; Nagar, Mona

2012-01-01

Statistical process control is the application of statistical methods to the measurement and analysis of variation process. Various regulatory authorities such as Validation Guidance for Industry (2011), International Conference on Harmonisation ICH Q10 (2009), the Health Canada guidelines (2009), Health Science Authority, Singapore: Guidance for Product Quality Review (2008), and International Organization for Standardization ISO-9000:2005 provide regulatory support for the application of statistical process control for better process control and understanding. In this study risk assessments, normal probability distributions, control charts, and capability charts are employed for selection of critical quality attributes, determination of normal probability distribution, statistical stability, and capability of production processes, respectively. The objective of this study is to determine tablet production process quality in the form of sigma process capability. By interpreting data and graph trends, forecasting of critical quality attributes, sigma process capability, and stability of process were studied. The overall study contributes to an assessment of process at the sigma level with respect to out-of-specification attributes produced. Finally, the study will point to an area where the application of quality improvement and quality risk assessment principles for achievement of six sigma-capable processes is possible. Statistical process control is the most advantageous tool for determination of the quality of any production process. This tool is new for the pharmaceutical tablet production process. In the case of pharmaceutical tablet production processes, the quality control parameters act as quality assessment parameters. Application of risk assessment provides selection of critical quality attributes among quality control parameters. Sequential application of normality distributions, control charts, and capability analyses provides a valid statistical process control study on process. Interpretation of such a study provides information about stability, process variability, changing of trends, and quantification of process ability against defective production. Comparative evaluation of critical quality attributes by Pareto charts provides the least capable and most variable process that is liable for improvement. Statistical process control thus proves to be an important tool for six sigma-capable process development and continuous quality improvement.

A practical approach for exploration and modeling of the design space of a bacterial vaccine cultivation process.

PubMed

Streefland, M; Van Herpen, P F G; Van de Waterbeemd, B; Van der Pol, L A; Beuvery, E C; Tramper, J; Martens, D E; Toft, M

2009-10-15

A licensed pharmaceutical process is required to be executed within the validated ranges throughout the lifetime of product manufacturing. Changes to the process, especially for processes involving biological products, usually require the manufacturer to demonstrate that the safety and efficacy of the product remains unchanged by new or additional clinical testing. Recent changes in the regulations for pharmaceutical processing allow broader ranges of process settings to be submitted for regulatory approval, the so-called process design space, which means that a manufacturer can optimize his process within the submitted ranges after the product has entered the market, which allows flexible processes. In this article, the applicability of this concept of the process design space is investigated for the cultivation process step for a vaccine against whooping cough disease. An experimental design (DoE) is applied to investigate the ranges of critical process parameters that still result in a product that meets specifications. The on-line process data, including near infrared spectroscopy, are used to build a descriptive model of the processes used in the experimental design. Finally, the data of all processes are integrated in a multivariate batch monitoring model that represents the investigated process design space. This article demonstrates how the general principles of PAT and process design space can be applied for an undefined biological product such as a whole cell vaccine. The approach chosen for model development described here, allows on line monitoring and control of cultivation batches in order to assure in real time that a process is running within the process design space.

Processing approaches to cognition: the impetus from the levels-of-processing framework.

PubMed

Roediger, Henry L; Gallo, David A; Geraci, Lisa

2002-01-01

Processing approaches to cognition have a long history, from act psychology to the present, but perhaps their greatest boost was given by the success and dominance of the levels-of-processing framework. We review the history of processing approaches, and explore the influence of the levels-of-processing approach, the procedural approach advocated by Paul Kolers, and the transfer-appropriate processing framework. Processing approaches emphasise the procedures of mind and the idea that memory storage can be usefully conceptualised as residing in the same neural units that originally processed information at the time of encoding. Processing approaches emphasise the unity and interrelatedness of cognitive processes and maintain that they can be dissected into separate faculties only by neglecting the richness of mental life. We end by pointing to future directions for processing approaches.

Global Sensitivity Analysis for Process Identification under Model Uncertainty

NASA Astrophysics Data System (ADS)

Ye, M.; Dai, H.; Walker, A. P.; Shi, L.; Yang, J.

2015-12-01

The environmental system consists of various physical, chemical, and biological processes, and environmental models are always built to simulate these processes and their interactions. For model building, improvement, and validation, it is necessary to identify important processes so that limited resources can be used to better characterize the processes. While global sensitivity analysis has been widely used to identify important processes, the process identification is always based on deterministic process conceptualization that uses a single model for representing a process. However, environmental systems are complex, and it happens often that a single process may be simulated by multiple alternative models. Ignoring the model uncertainty in process identification may lead to biased identification in that identified important processes may not be so in the real world. This study addresses this problem by developing a new method of global sensitivity analysis for process identification. The new method is based on the concept of Sobol sensitivity analysis and model averaging. Similar to the Sobol sensitivity analysis to identify important parameters, our new method evaluates variance change when a process is fixed at its different conceptualizations. The variance considers both parametric and model uncertainty using the method of model averaging. The method is demonstrated using a synthetic study of groundwater modeling that considers recharge process and parameterization process. Each process has two alternative models. Important processes of groundwater flow and transport are evaluated using our new method. The method is mathematically general, and can be applied to a wide range of environmental problems.

A new process sensitivity index to identify important system processes under process model and parametric uncertainty

DOE PAGES

Dai, Heng; Ye, Ming; Walker, Anthony P.; ...

2017-03-28

A hydrological model consists of multiple process level submodels, and each submodel represents a process key to the operation of the simulated system. Global sensitivity analysis methods have been widely used to identify important processes for system model development and improvement. The existing methods of global sensitivity analysis only consider parametric uncertainty, and are not capable of handling model uncertainty caused by multiple process models that arise from competing hypotheses about one or more processes. To address this problem, this study develops a new method to probe model output sensitivity to competing process models by integrating model averaging methods withmore » variance-based global sensitivity analysis. A process sensitivity index is derived as a single summary measure of relative process importance, and the index includes variance in model outputs caused by uncertainty in both process models and their parameters. Here, for demonstration, the new index is used to assign importance to the processes of recharge and geology in a synthetic study of groundwater reactive transport modeling. The recharge process is simulated by two models that convert precipitation to recharge, and the geology process is simulated by two models of hydraulic conductivity. Each process model has its own random parameters. Finally, the new process sensitivity index is mathematically general, and can be applied to a wide range of problems in hydrology and beyond.« less

A new process sensitivity index to identify important system processes under process model and parametric uncertainty

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Heng; Ye, Ming; Walker, Anthony P.

A hydrological model consists of multiple process level submodels, and each submodel represents a process key to the operation of the simulated system. Global sensitivity analysis methods have been widely used to identify important processes for system model development and improvement. The existing methods of global sensitivity analysis only consider parametric uncertainty, and are not capable of handling model uncertainty caused by multiple process models that arise from competing hypotheses about one or more processes. To address this problem, this study develops a new method to probe model output sensitivity to competing process models by integrating model averaging methods withmore » variance-based global sensitivity analysis. A process sensitivity index is derived as a single summary measure of relative process importance, and the index includes variance in model outputs caused by uncertainty in both process models and their parameters. Here, for demonstration, the new index is used to assign importance to the processes of recharge and geology in a synthetic study of groundwater reactive transport modeling. The recharge process is simulated by two models that convert precipitation to recharge, and the geology process is simulated by two models of hydraulic conductivity. Each process model has its own random parameters. Finally, the new process sensitivity index is mathematically general, and can be applied to a wide range of problems in hydrology and beyond.« less

Social Network Supported Process Recommender System

PubMed Central

Ye, Yanming; Yin, Jianwei; Xu, Yueshen

2014-01-01

Process recommendation technologies have gained more and more attention in the field of intelligent business process modeling to assist the process modeling. However, most of the existing technologies only use the process structure analysis and do not take the social features of processes into account, while the process modeling is complex and comprehensive in most situations. This paper studies the feasibility of social network research technologies on process recommendation and builds a social network system of processes based on the features similarities. Then, three process matching degree measurements are presented and the system implementation is discussed subsequently. Finally, experimental evaluations and future works are introduced. PMID:24672309

A model for process representation and synthesis. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Thomas, R. H.

1971-01-01

The problem of representing groups of loosely connected processes is investigated, and a model for process representation useful for synthesizing complex patterns of process behavior is developed. There are three parts, the first part isolates the concepts which form the basis for the process representation model by focusing on questions such as: What is a process; What is an event; Should one process be able to restrict the capabilities of another? The second part develops a model for process representation which captures the concepts and intuitions developed in the first part. The model presented is able to describe both the internal structure of individual processes and the interface structure between interacting processes. Much of the model's descriptive power derives from its use of the notion of process state as a vehicle for relating the internal and external aspects of process behavior. The third part demonstrates by example that the model for process representation is a useful one for synthesizing process behavior patterns. In it the model is used to define a variety of interesting process behavior patterns. The dissertation closes by suggesting how the model could be used as a semantic base for a very potent language extension facility.

Process and Post-Process: A Discursive History.

ERIC Educational Resources Information Center

Matsuda, Paul Kei

2003-01-01

Examines the history of process and post-process in composition studies, focusing on ways in which terms, such as "current-traditional rhetoric,""process," and "post-process" have contributed to the discursive construction of reality. Argues that use of the term post-process in the context of second language writing needs to be guided by a…

Improving operational anodising process performance using simulation approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liong, Choong-Yeun, E-mail: lg@ukm.edu.my; Ghazali, Syarah Syahidah, E-mail: syarah@gapps.kptm.edu.my

The use of aluminium is very widespread, especially in transportation, electrical and electronics, architectural, automotive and engineering applications sectors. Therefore, the anodizing process is an important process for aluminium in order to make the aluminium durable, attractive and weather resistant. This research is focused on the anodizing process operations in manufacturing and supplying of aluminium extrusion. The data required for the development of the model is collected from the observations and interviews conducted in the study. To study the current system, the processes involved in the anodizing process are modeled by using Arena 14.5 simulation software. Those processes consist ofmore » five main processes, namely the degreasing process, the etching process, the desmut process, the anodizing process, the sealing process and 16 other processes. The results obtained were analyzed to identify the problems or bottlenecks that occurred and to propose improvement methods that can be implemented on the original model. Based on the comparisons that have been done between the improvement methods, the productivity could be increased by reallocating the workers and reducing loading time.« less

Feller processes: the next generation in modeling. Brownian motion, Lévy processes and beyond.

PubMed

Böttcher, Björn

2010-12-03

We present a simple construction method for Feller processes and a framework for the generation of sample paths of Feller processes. The construction is based on state space dependent mixing of Lévy processes. Brownian Motion is one of the most frequently used continuous time Markov processes in applications. In recent years also Lévy processes, of which Brownian Motion is a special case, have become increasingly popular. Lévy processes are spatially homogeneous, but empirical data often suggest the use of spatially inhomogeneous processes. Thus it seems necessary to go to the next level of generalization: Feller processes. These include Lévy processes and in particular brownian motion as special cases but allow spatial inhomogeneities. Many properties of Feller processes are known, but proving the very existence is, in general, very technical. Moreover, an applicable framework for the generation of sample paths of a Feller process was missing. We explain, with practitioners in mind, how to overcome both of these obstacles. In particular our simulation technique allows to apply Monte Carlo methods to Feller processes.

Feller Processes: The Next Generation in Modeling. Brownian Motion, Lévy Processes and Beyond

PubMed Central

Böttcher, Björn

2010-01-01

We present a simple construction method for Feller processes and a framework for the generation of sample paths of Feller processes. The construction is based on state space dependent mixing of Lévy processes. Brownian Motion is one of the most frequently used continuous time Markov processes in applications. In recent years also Lévy processes, of which Brownian Motion is a special case, have become increasingly popular. Lévy processes are spatially homogeneous, but empirical data often suggest the use of spatially inhomogeneous processes. Thus it seems necessary to go to the next level of generalization: Feller processes. These include Lévy processes and in particular Brownian motion as special cases but allow spatial inhomogeneities. Many properties of Feller processes are known, but proving the very existence is, in general, very technical. Moreover, an applicable framework for the generation of sample paths of a Feller process was missing. We explain, with practitioners in mind, how to overcome both of these obstacles. In particular our simulation technique allows to apply Monte Carlo methods to Feller processes. PMID:21151931

AIRSAR Automated Web-based Data Processing and Distribution System

NASA Technical Reports Server (NTRS)

Chu, Anhua; vanZyl, Jakob; Kim, Yunjin; Lou, Yunling; Imel, David; Tung, Wayne; Chapman, Bruce; Durden, Stephen

2005-01-01

In this paper, we present an integrated, end-to-end synthetic aperture radar (SAR) processing system that accepts data processing requests, submits processing jobs, performs quality analysis, delivers and archives processed data. This fully automated SAR processing system utilizes database and internet/intranet web technologies to allow external users to browse and submit data processing requests and receive processed data. It is a cost-effective way to manage a robust SAR processing and archival system. The integration of these functions has reduced operator errors and increased processor throughput dramatically.

Simplified process model discovery based on role-oriented genetic mining.

PubMed

Zhao, Weidong; Liu, Xi; Dai, Weihui

2014-01-01

Process mining is automated acquisition of process models from event logs. Although many process mining techniques have been developed, most of them are based on control flow. Meanwhile, the existing role-oriented process mining methods focus on correctness and integrity of roles while ignoring role complexity of the process model, which directly impacts understandability and quality of the model. To address these problems, we propose a genetic programming approach to mine the simplified process model. Using a new metric of process complexity in terms of roles as the fitness function, we can find simpler process models. The new role complexity metric of process models is designed from role cohesion and coupling, and applied to discover roles in process models. Moreover, the higher fitness derived from role complexity metric also provides a guideline for redesigning process models. Finally, we conduct case study and experiments to show that the proposed method is more effective for streamlining the process by comparing with related studies.

Electrotechnologies to process foods

USDA-ARS?s Scientific Manuscript database

Electrical energy is being used to process foods. In conventional food processing plants, electricity drives mechanical devices and controls the degree of process. In recent years, several processing technologies are being developed to process foods directly with electricity. Electrotechnologies use...

Challenges associated with the implementation of the nursing process: A systematic review.

PubMed

Zamanzadeh, Vahid; Valizadeh, Leila; Tabrizi, Faranak Jabbarzadeh; Behshid, Mojghan; Lotfi, Mojghan

2015-01-01

Nursing process is a scientific approach in the provision of qualified nursing cares. However, in practice, the implementation of this process is faced with numerous challenges. With the knowledge of the challenges associated with the implementation of the nursing process, the nursing processes can be developed appropriately. Due to the lack of comprehensive information on this subject, the current study was carried out to assess the key challenges associated with the implementation of the nursing process. To achieve and review related studies on this field, databases of Iran medix, SID, Magiran, PUBMED, Google scholar, and Proquest were assessed using the main keywords of nursing process and nursing process systematic review. The articles were retrieved in three steps including searching by keywords, review of the proceedings based on inclusion criteria, and final retrieval and assessment of available full texts. Systematic assessment of the articles showed different challenges in implementation of the nursing process. Intangible understanding of the concept of nursing process, different views of the process, lack of knowledge and awareness among nurses related to the execution of process, supports of managing systems, and problems related to recording the nursing process were the main challenges that were extracted from review of literature. On systematically reviewing the literature, intangible understanding of the concept of nursing process has been identified as the main challenge in nursing process. To achieve the best strategy to minimize the challenge, in addition to preparing facilitators for implementation of nursing process, intangible understanding of the concept of nursing process, different views of the process, and forming teams of experts in nursing education are recommended for internalizing the nursing process among nurses.

Challenges associated with the implementation of the nursing process: A systematic review

PubMed Central

Zamanzadeh, Vahid; Valizadeh, Leila; Tabrizi, Faranak Jabbarzadeh; Behshid, Mojghan; Lotfi, Mojghan

2015-01-01

Background: Nursing process is a scientific approach in the provision of qualified nursing cares. However, in practice, the implementation of this process is faced with numerous challenges. With the knowledge of the challenges associated with the implementation of the nursing process, the nursing processes can be developed appropriately. Due to the lack of comprehensive information on this subject, the current study was carried out to assess the key challenges associated with the implementation of the nursing process. Materials and Methods: To achieve and review related studies on this field, databases of Iran medix, SID, Magiran, PUBMED, Google scholar, and Proquest were assessed using the main keywords of nursing process and nursing process systematic review. The articles were retrieved in three steps including searching by keywords, review of the proceedings based on inclusion criteria, and final retrieval and assessment of available full texts. Results: Systematic assessment of the articles showed different challenges in implementation of the nursing process. Intangible understanding of the concept of nursing process, different views of the process, lack of knowledge and awareness among nurses related to the execution of process, supports of managing systems, and problems related to recording the nursing process were the main challenges that were extracted from review of literature. Conclusions: On systematically reviewing the literature, intangible understanding of the concept of nursing process has been identified as the main challenge in nursing process. To achieve the best strategy to minimize the challenge, in addition to preparing facilitators for implementation of nursing process, intangible understanding of the concept of nursing process, different views of the process, and forming teams of experts in nursing education are recommended for internalizing the nursing process among nurses. PMID:26257793

Automated synthesis of image processing procedures using AI planning techniques

NASA Technical Reports Server (NTRS)

Chien, Steve; Mortensen, Helen

1994-01-01

This paper describes the Multimission VICAR (Video Image Communication and Retrieval) Planner (MVP) (Chien 1994) system, which uses artificial intelligence planning techniques (Iwasaki & Friedland, 1985, Pemberthy & Weld, 1992, Stefik, 1981) to automatically construct executable complex image processing procedures (using models of the smaller constituent image processing subprograms) in response to image processing requests made to the JPL Multimission Image Processing Laboratory (MIPL). The MVP system allows the user to specify the image processing requirements in terms of the various types of correction required. Given this information, MVP derives unspecified required processing steps and determines appropriate image processing programs and parameters to achieve the specified image processing goals. This information is output as an executable image processing program which can then be executed to fill the processing request.

Optimisation of shock absorber process parameters using failure mode and effect analysis and genetic algorithm

NASA Astrophysics Data System (ADS)

Mariajayaprakash, Arokiasamy; Senthilvelan, Thiyagarajan; Vivekananthan, Krishnapillai Ponnambal

2013-07-01

The various process parameters affecting the quality characteristics of the shock absorber during the process were identified using the Ishikawa diagram and by failure mode and effect analysis. The identified process parameters are welding process parameters (squeeze, heat control, wheel speed, and air pressure), damper sealing process parameters (load, hydraulic pressure, air pressure, and fixture height), washing process parameters (total alkalinity, temperature, pH value of rinsing water, and timing), and painting process parameters (flowability, coating thickness, pointage, and temperature). In this paper, the process parameters, namely, painting and washing process parameters, are optimized by Taguchi method. Though the defects are reasonably minimized by Taguchi method, in order to achieve zero defects during the processes, genetic algorithm technique is applied on the optimized parameters obtained by Taguchi method.

Methods, media and systems for managing a distributed application running in a plurality of digital processing devices

DOEpatents

Laadan, Oren; Nieh, Jason; Phung, Dan

2012-10-02

Methods, media and systems for managing a distributed application running in a plurality of digital processing devices are provided. In some embodiments, a method includes running one or more processes associated with the distributed application in virtualized operating system environments on a plurality of digital processing devices, suspending the one or more processes, and saving network state information relating to network connections among the one or more processes. The method further include storing process information relating to the one or more processes, recreating the network connections using the saved network state information, and restarting the one or more processes using the stored process information.

SEMICONDUCTOR TECHNOLOGY A signal processing method for the friction-based endpoint detection system of a CMP process

NASA Astrophysics Data System (ADS)

Chi, Xu; Dongming, Guo; Zhuji, Jin; Renke, Kang

2010-12-01

A signal processing method for the friction-based endpoint detection system of a chemical mechanical polishing (CMP) process is presented. The signal process method uses the wavelet threshold denoising method to reduce the noise contained in the measured original signal, extracts the Kalman filter innovation from the denoised signal as the feature signal, and judges the CMP endpoint based on the feature of the Kalman filter innovation sequence during the CMP process. Applying the signal processing method, the endpoint detection experiments of the Cu CMP process were carried out. The results show that the signal processing method can judge the endpoint of the Cu CMP process.

Composite faces are not (necessarily) processed coactively: A test using systems factorial technology and logical-rule models.

PubMed

Cheng, Xue Jun; McCarthy, Callum J; Wang, Tony S L; Palmeri, Thomas J; Little, Daniel R

2018-06-01

Upright faces are thought to be processed more holistically than inverted faces. In the widely used composite face paradigm, holistic processing is inferred from interference in recognition performance from a to-be-ignored face half for upright and aligned faces compared with inverted or misaligned faces. We sought to characterize the nature of holistic processing in composite faces in computational terms. We use logical-rule models (Fifić, Little, & Nosofsky, 2010) and Systems Factorial Technology (Townsend & Nozawa, 1995) to examine whether composite faces are processed through pooling top and bottom face halves into a single processing channel-coactive processing-which is one common mechanistic definition of holistic processing. By specifically operationalizing holistic processing as the pooling of features into a single decision process in our task, we are able to distinguish it from other processing models that may underlie composite face processing. For instance, a failure of selective attention might result even when top and bottom components of composite faces are processed in serial or in parallel without processing the entire face coactively. Our results show that performance is best explained by a mixture of serial and parallel processing architectures across all 4 upright and inverted, aligned and misaligned face conditions. The results indicate multichannel, featural processing of composite faces in a manner inconsistent with the notion of coactivity. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Fuzzy image processing in sun sensor

NASA Technical Reports Server (NTRS)

Mobasser, S.; Liebe, C. C.; Howard, A.

2003-01-01

This paper will describe how the fuzzy image processing is implemented in the instrument. Comparison of the Fuzzy image processing and a more conventional image processing algorithm is provided and shows that the Fuzzy image processing yields better accuracy then conventional image processing.

DESIGNING ENVIRONMENTAL, ECONOMIC AND ENERGY EFFICIENT CHEMICAL PROCESSES

EPA Science Inventory

The design and improvement of chemical processes can be very challenging. The earlier energy conservation, process economics and environmental aspects are incorporated into the process development, the easier and less expensive it is to alter the process design. Process emissio...

Reversing the conventional leather processing sequence for cleaner leather production.

PubMed

Saravanabhavan, Subramani; Thanikaivelan, Palanisamy; Rao, Jonnalagadda Raghava; Nair, Balachandran Unni; Ramasami, Thirumalachari

2006-02-01

Conventional leather processing generally involves a combination of single and multistep processes that employs as well as expels various biological, inorganic, and organic materials. It involves nearly 14-15 steps and discharges a huge amount of pollutants. This is primarily due to the fact that conventional leather processing employs a "do-undo" process logic. In this study, the conventional leather processing steps have been reversed to overcome the problems associated with the conventional method. The charges of the skin matrix and of the chemicals and pH profiles of the process have been judiciously used for reversing the process steps. This reversed process eventually avoids several acidification and basification/neutralization steps used in conventional leather processing. The developed process has been validated through various analyses such as chromium content, shrinkage temperature, softness measurements, scanning electron microscopy, and physical testing of the leathers. Further, the performance of the leathers is shown to be on par with conventionally processed leathers through bulk property evaluation. The process enjoys a significant reduction in COD and TS by 53 and 79%, respectively. Water consumption and discharge is reduced by 65 and 64%, respectively. Also, the process benefits from significant reduction in chemicals, time, power, and cost compared to the conventional process.

Group processing in an undergraduate biology course for preservice teachers: Experiences and attitudes

NASA Astrophysics Data System (ADS)

Schellenberger, Lauren Brownback

Group processing is a key principle of cooperative learning in which small groups discuss their strengths and weaknesses and set group goals or norms. However, group processing has not been well-studied at the post-secondary level or from a qualitative or mixed methods perspective. This mixed methods study uses a phenomenological framework to examine the experience of group processing for students in an undergraduate biology course for preservice teachers. The effect of group processing on students' attitudes toward future group work and group processing is also examined. Additionally, this research investigated preservice teachers' plans for incorporating group processing into future lessons. Students primarily experienced group processing as a time to reflect on past performance. Also, students experienced group processing as a time to increase communication among group members and become motivated for future group assignments. Three factors directly influenced students' experiences with group processing: (1) previous experience with group work, (2) instructor interaction, and (3) gender. Survey data indicated that group processing had a slight positive effect on students' attitudes toward future group work and group processing. Participants who were interviewed felt that group processing was an important part of group work and that it had increased their group's effectiveness as well as their ability to work effectively with other people. Participants held positive views on group work prior to engaging in group processing, and group processing did not alter their atittude toward group work. Preservice teachers who were interviewed planned to use group work and a modified group processing protocol in their future classrooms. They also felt that group processing had prepared them for their future professions by modeling effective collaboration and group skills. Based on this research, a new model for group processing has been created which includes extensive instructor interaction and additional group processing sessions. This study offers a new perspective on the phenomenon of group processing and informs science educators and teacher educators on the effective implementation of this important component of small-group learning.

Properties of the Bivariate Delayed Poisson Process

DTIC Science & Technology

1974-07-01

and Lewis (1972) in their Berkeley Symposium paper and here their analysis of the bivariate Poisson processes (without Poisson noise) is carried... Poisson processes . They cannot, however, be independent Poisson processes because their events are associated in pairs by the displace- ment centres...process because its marginal processes for events of each type are themselves (univariate) Poisson processes . Cox and Lewis (1972) assumed a

The Application of Six Sigma Methodologies to University Processes: The Use of Student Teams

ERIC Educational Resources Information Center

Pryor, Mildred Golden; Alexander, Christine; Taneja, Sonia; Tirumalasetty, Sowmya; Chadalavada, Deepthi

2012-01-01

The first student Six Sigma team (activated under a QEP Process Sub-team) evaluated the course and curriculum approval process. The goal was to streamline the process and thereby shorten process cycle time and reduce confusion about how the process works. Members of this team developed flowcharts on how the process is supposed to work (by…

Impact of Radio Frequency Identification (RFID) on the Marine Corps’ Supply Process

DTIC Science & Technology

2006-09-01

Hypothetical Improvement Using a Real-Time Order Processing System Vice a Batch Order Processing System ................56 3. As-Is: The Current... Processing System Vice a Batch Order Processing System ................58 V. RESULTS ................................................69 A. SIMULATION...Time: Hypothetical Improvement Using a Real-Time Order Processing System Vice a Batch Order Processing System ................71 3. As-Is: The

Global-local processing relates to spatial and verbal processing: implications for sex differences in cognition.

PubMed

Pletzer, Belinda; Scheuringer, Andrea; Scherndl, Thomas

2017-09-05

Sex differences have been reported for a variety of cognitive tasks and related to the use of different cognitive processing styles in men and women. It was recently argued that these processing styles share some characteristics across tasks, i.e. male approaches are oriented towards holistic stimulus aspects and female approaches are oriented towards stimulus details. In that respect, sex-dependent cognitive processing styles share similarities with attentional global-local processing. A direct relationship between cognitive processing and global-local processing has however not been previously established. In the present study, 49 men and 44 women completed a Navon paradigm and a Kimchi Palmer task as well as a navigation task and a verbal fluency task with the goal to relate the global advantage (GA) effect as a measure of global processing to holistic processing styles in both tasks. Indeed participants with larger GA effects displayed more holistic processing during spatial navigation and phonemic fluency. However, the relationship to cognitive processing styles was modulated by the specific condition of the Navon paradigm, as well as the sex of participants. Thus, different types of global-local processing play different roles for cognitive processing in men and women.

21 CFR 113.83 - Establishing scheduled processes.

Code of Federal Regulations, 2012 CFR

2012-04-01

... competent processing authorities. If incubation tests are necessary for process confirmation, they shall... instituting the process. The incubation tests for confirmation of the scheduled processes should include the.... Complete records covering all aspects of the establishment of the process and associated incubation tests...

21 CFR 113.83 - Establishing scheduled processes.

Code of Federal Regulations, 2014 CFR

2014-04-01

... competent processing authorities. If incubation tests are necessary for process confirmation, they shall... instituting the process. The incubation tests for confirmation of the scheduled processes should include the.... Complete records covering all aspects of the establishment of the process and associated incubation tests...

21 CFR 113.83 - Establishing scheduled processes.

Code of Federal Regulations, 2013 CFR

2013-04-01

... competent processing authorities. If incubation tests are necessary for process confirmation, they shall... instituting the process. The incubation tests for confirmation of the scheduled processes should include the.... Complete records covering all aspects of the establishment of the process and associated incubation tests...

A mathematical study of a random process proposed as an atmospheric turbulence model

NASA Technical Reports Server (NTRS)

Sidwell, K.

1977-01-01

A random process is formed by the product of a local Gaussian process and a random amplitude process, and the sum of that product with an independent mean value process. The mathematical properties of the resulting process are developed, including the first and second order properties and the characteristic function of general order. An approximate method for the analysis of the response of linear dynamic systems to the process is developed. The transition properties of the process are also examined.

Standard services for the capture, processing, and distribution of packetized telemetry data

NASA Technical Reports Server (NTRS)

Stallings, William H.

1989-01-01

Standard functional services for the capture, processing, and distribution of packetized data are discussed with particular reference to the future implementation of packet processing systems, such as those for the Space Station Freedom. The major functions are listed under the following major categories: input processing, packet processing, and output processing. A functional block diagram of a packet data processing facility is presented, showing the distribution of the various processing functions as well as the primary data flow through the facility.

Assessment of hospital processes using a process mining technique: Outpatient process analysis at a tertiary hospital.

PubMed

Yoo, Sooyoung; Cho, Minsu; Kim, Eunhye; Kim, Seok; Sim, Yerim; Yoo, Donghyun; Hwang, Hee; Song, Minseok

2016-04-01

Many hospitals are increasing their efforts to improve processes because processes play an important role in enhancing work efficiency and reducing costs. However, to date, a quantitative tool has not been available to examine the before and after effects of processes and environmental changes, other than the use of indirect indicators, such as mortality rate and readmission rate. This study used process mining technology to analyze process changes based on changes in the hospital environment, such as the construction of a new building, and to measure the effects of environmental changes in terms of consultation wait time, time spent per task, and outpatient care processes. Using process mining technology, electronic health record (EHR) log data of outpatient care before and after constructing a new building were analyzed, and the effectiveness of the technology in terms of the process was evaluated. Using the process mining technique, we found that the total time spent in outpatient care did not increase significantly compared to that before the construction of a new building, considering that the number of outpatients increased, and the consultation wait time decreased. These results suggest that the operation of the outpatient clinic was effective after changes were implemented in the hospital environment. We further identified improvements in processes using the process mining technique, thereby demonstrating the usefulness of this technique for analyzing complex hospital processes at a low cost. This study confirmed the effectiveness of process mining technology at an actual hospital site. In future studies, the use of process mining technology will be expanded by applying this approach to a larger variety of process change situations. Copyright © 2016. Published by Elsevier Ireland Ltd.

Study of process variables associated with manufacturing hermetically-sealed nickel-cadmium cells

NASA Technical Reports Server (NTRS)

Miller, L.

1974-01-01

A two year study of the major process variables associated with the manufacturing process for sealed, nickel-cadmium, areospace cells is summarized. Effort was directed toward identifying the major process variables associated with a manufacturing process, experimentally assessing each variable's effect, and imposing the necessary changes (optimization) and controls for the critical process variables to improve results and uniformity. A critical process variable associated with the sintered nickel plaque manufacturing process was identified as the manual forming operation. Critical process variables identified with the positive electrode impregnation/polarization process were impregnation solution temperature, free acid content, vacuum impregnation, and sintered plaque strength. Positive and negative electrodes were identified as a major source of carbonate contamination in sealed cells.

Monitoring autocorrelated process: A geometric Brownian motion process approach

NASA Astrophysics Data System (ADS)

Li, Lee Siaw; Djauhari, Maman A.

2013-09-01

Autocorrelated process control is common in today's modern industrial process control practice. The current practice of autocorrelated process control is to eliminate the autocorrelation by using an appropriate model such as Box-Jenkins models or other models and then to conduct process control operation based on the residuals. In this paper we show that many time series are governed by a geometric Brownian motion (GBM) process. Therefore, in this case, by using the properties of a GBM process, we only need an appropriate transformation and model the transformed data to come up with the condition needs in traditional process control. An industrial example of cocoa powder production process in a Malaysian company will be presented and discussed to illustrate the advantages of the GBM approach.

Meta-control of combustion performance with a data mining approach

NASA Astrophysics Data System (ADS)

Song, Zhe

Large scale combustion process is complex and proposes challenges of optimizing its performance. Traditional approaches based on thermal dynamics have limitations on finding optimal operational regions due to time-shift nature of the process. Recent advances in information technology enable people collect large volumes of process data easily and continuously. The collected process data contains rich information about the process and, to some extent, represents a digital copy of the process over time. Although large volumes of data exist in industrial combustion processes, they are not fully utilized to the level where the process can be optimized. Data mining is an emerging science which finds patterns or models from large data sets. It has found many successful applications in business marketing, medical and manufacturing domains The focus of this dissertation is on applying data mining to industrial combustion processes, and ultimately optimizing the combustion performance. However the philosophy, methods and frameworks discussed in this research can also be applied to other industrial processes. Optimizing an industrial combustion process has two major challenges. One is the underlying process model changes over time and obtaining an accurate process model is nontrivial. The other is that a process model with high fidelity is usually highly nonlinear, solving the optimization problem needs efficient heuristics. This dissertation is set to solve these two major challenges. The major contribution of this 4-year research is the data-driven solution to optimize the combustion process, where process model or knowledge is identified based on the process data, then optimization is executed by evolutionary algorithms to search for optimal operating regions.

5 CFR 1653.13 - Processing legal processes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Processing legal processes. 1653.13 Section 1653.13 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD COURT ORDERS AND LEGAL PROCESSES AFFECTING THRIFT SAVINGS PLAN ACCOUNTS Legal Process for the Enforcement of a Participant's Legal...

5 CFR 1653.13 - Processing legal processes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Processing legal processes. 1653.13 Section 1653.13 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD COURT ORDERS AND LEGAL PROCESSES AFFECTING THRIFT SAVINGS PLAN ACCOUNTS Legal Process for the Enforcement of a Participant's Legal...

A Search Algorithm for Generating Alternative Process Plans in Flexible Manufacturing System

NASA Astrophysics Data System (ADS)

Tehrani, Hossein; Sugimura, Nobuhiro; Tanimizu, Yoshitaka; Iwamura, Koji

Capabilities and complexity of manufacturing systems are increasing and striving for an integrated manufacturing environment. Availability of alternative process plans is a key factor for integration of design, process planning and scheduling. This paper describes an algorithm for generation of alternative process plans by extending the existing framework of the process plan networks. A class diagram is introduced for generating process plans and process plan networks from the viewpoint of the integrated process planning and scheduling systems. An incomplete search algorithm is developed for generating and searching the process plan networks. The benefit of this algorithm is that the whole process plan network does not have to be generated before the search algorithm starts. This algorithm is applicable to large and enormous process plan networks and also to search wide areas of the network based on the user requirement. The algorithm can generate alternative process plans and to select a suitable one based on the objective functions.

PyMS: a Python toolkit for processing of gas chromatography-mass spectrometry (GC-MS) data. Application and comparative study of selected tools.

PubMed

O'Callaghan, Sean; De Souza, David P; Isaac, Andrew; Wang, Qiao; Hodkinson, Luke; Olshansky, Moshe; Erwin, Tim; Appelbe, Bill; Tull, Dedreia L; Roessner, Ute; Bacic, Antony; McConville, Malcolm J; Likić, Vladimir A

2012-05-30

Gas chromatography-mass spectrometry (GC-MS) is a technique frequently used in targeted and non-targeted measurements of metabolites. Most existing software tools for processing of raw instrument GC-MS data tightly integrate data processing methods with graphical user interface facilitating interactive data processing. While interactive processing remains critically important in GC-MS applications, high-throughput studies increasingly dictate the need for command line tools, suitable for scripting of high-throughput, customized processing pipelines. PyMS comprises a library of functions for processing of instrument GC-MS data developed in Python. PyMS currently provides a complete set of GC-MS processing functions, including reading of standard data formats (ANDI- MS/NetCDF and JCAMP-DX), noise smoothing, baseline correction, peak detection, peak deconvolution, peak integration, and peak alignment by dynamic programming. A novel common ion single quantitation algorithm allows automated, accurate quantitation of GC-MS electron impact (EI) fragmentation spectra when a large number of experiments are being analyzed. PyMS implements parallel processing for by-row and by-column data processing tasks based on Message Passing Interface (MPI), allowing processing to scale on multiple CPUs in distributed computing environments. A set of specifically designed experiments was performed in-house and used to comparatively evaluate the performance of PyMS and three widely used software packages for GC-MS data processing (AMDIS, AnalyzerPro, and XCMS). PyMS is a novel software package for the processing of raw GC-MS data, particularly suitable for scripting of customized processing pipelines and for data processing in batch mode. PyMS provides limited graphical capabilities and can be used both for routine data processing and interactive/exploratory data analysis. In real-life GC-MS data processing scenarios PyMS performs as well or better than leading software packages. We demonstrate data processing scenarios simple to implement in PyMS, yet difficult to achieve with many conventional GC-MS data processing software. Automated sample processing and quantitation with PyMS can provide substantial time savings compared to more traditional interactive software systems that tightly integrate data processing with the graphical user interface.

Processing mode during repetitive thinking in socially anxious individuals: evidence for a maladaptive experiential mode.

PubMed

Wong, Quincy J J; Moulds, Michelle L

2012-12-01

Evidence from the depression literature suggests that an analytical processing mode adopted during repetitive thinking leads to maladaptive outcomes relative to an experiential processing mode. To date, in socially anxious individuals, the impact of processing mode during repetitive thinking related to an actual social-evaluative situation has not been investigated. We thus tested whether an analytical processing mode would be maladaptive relative to an experiential processing mode during anticipatory processing and post-event rumination. High and low socially anxious participants were induced to engage in either an analytical or experiential processing mode during: (a) anticipatory processing before performing a speech (Experiment 1; N = 94), or (b) post-event rumination after performing a speech (Experiment 2; N = 74). Mood, cognition, and behavioural measures were employed to examine the effects of processing mode. For high socially anxious participants, the modes had a similar effect on self-reported anxiety during both anticipatory processing and post-event rumination. Unexpectedly, relative to the analytical mode, the experiential mode led to stronger high standard and conditional beliefs during anticipatory processing, and stronger unconditional beliefs during post-event rumination. These experiments are the first to investigate processing mode during anticipatory processing and post-event rumination. Hence, these results are novel and will need to be replicated. These findings suggest that an experiential processing mode is maladaptive relative to an analytical processing mode during repetitive thinking characteristic of socially anxious individuals. Copyright © 2012 Elsevier Ltd. All rights reserved.

Using process elicitation and validation to understand and improve chemotherapy ordering and delivery.

PubMed

Mertens, Wilson C; Christov, Stefan C; Avrunin, George S; Clarke, Lori A; Osterweil, Leon J; Cassells, Lucinda J; Marquard, Jenna L

2012-11-01

Chemotherapy ordering and administration, in which errors have potentially severe consequences, was quantitatively and qualitatively evaluated by employing process formalism (or formal process definition), a technique derived from software engineering, to elicit and rigorously describe the process, after which validation techniques were applied to confirm the accuracy of the described process. The chemotherapy ordering and administration process, including exceptional situations and individuals' recognition of and responses to those situations, was elicited through informal, unstructured interviews with members of an interdisciplinary team. The process description (or process definition), written in a notation developed for software quality assessment purposes, guided process validation (which consisted of direct observations and semistructured interviews to confirm the elicited details for the treatment plan portion of the process). The overall process definition yielded 467 steps; 207 steps (44%) were dedicated to handling 59 exceptional situations. Validation yielded 82 unique process events (35 new expected but not yet described steps, 16 new exceptional situations, and 31 new steps in response to exceptional situations). Process participants actively altered the process as ambiguities and conflicts were discovered by the elicitation and validation components of the study. Chemotherapy error rates declined significantly during and after the project, which was conducted from October 2007 through August 2008. Each elicitation method and the subsequent validation discussions contributed uniquely to understanding the chemotherapy treatment plan review process, supporting rapid adoption of changes, improved communication regarding the process, and ensuing error reduction.

Modeling interdependencies between business and communication processes in hospitals.

PubMed

Brigl, Birgit; Wendt, Thomas; Winter, Alfred

2003-01-01

The optimization and redesign of business processes in hospitals is an important challenge for the hospital information management who has to design and implement a suitable HIS architecture. Nevertheless, there are no tools available specializing in modeling information-driven business processes and the consequences on the communication between information processing, tools. Therefore, we will present an approach which facilitates the representation and analysis of business processes and resulting communication processes between application components and their interdependencies. This approach aims not only to visualize those processes, but to also to evaluate if there are weaknesses concerning the information processing infrastructure which hinder the smooth implementation of the business processes.

Life cycle analysis within pharmaceutical process optimization and intensification: case study of active pharmaceutical ingredient production.

PubMed

Ott, Denise; Kralisch, Dana; Denčić, Ivana; Hessel, Volker; Laribi, Yosra; Perrichon, Philippe D; Berguerand, Charline; Kiwi-Minsker, Lioubov; Loeb, Patrick

2014-12-01

As the demand for new drugs is rising, the pharmaceutical industry faces the quest of shortening development time, and thus, reducing the time to market. Environmental aspects typically still play a minor role within the early phase of process development. Nevertheless, it is highly promising to rethink, redesign, and optimize process strategies as early as possible in active pharmaceutical ingredient (API) process development, rather than later at the stage of already established processes. The study presented herein deals with a holistic life-cycle-based process optimization and intensification of a pharmaceutical production process targeting a low-volume, high-value API. Striving for process intensification by transfer from batch to continuous processing, as well as an alternative catalytic system, different process options are evaluated with regard to their environmental impact to identify bottlenecks and improvement potentials for further process development activities. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

SOI-CMOS Process for Monolithic, Radiation-Tolerant, Science-Grade Imagers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, George; Lee, Adam

In Phase I, Voxtel worked with Jazz and Sandia to document and simulate the processes necessary to implement a DH-BSI SOI CMOS imaging process. The development is based upon mature SOI CMOS process at both fabs, with the addition of only a few custom processing steps for integration and electrical interconnection of the fully-depleted photodetectors. In Phase I, Voxtel also characterized the Sandia process, including the CMOS7 design rules, and we developed the outline of a process option that included a “BOX etch”, that will permit a “detector in handle” SOI CMOS process to be developed The process flows weremore » developed in cooperation with both Jazz and Sandia process engineers, along with detailed TCAD modeling and testing of the photodiode array architectures. In addition, Voxtel tested the radiation performance of the Jazz’s CA18HJ process, using standard and circular-enclosed transistors.« less

Face to face with emotion: holistic face processing is modulated by emotional state.

PubMed

Curby, Kim M; Johnson, Kareem J; Tyson, Alyssa

2012-01-01

Negative emotions are linked with a local, rather than global, visual processing style, which may preferentially facilitate feature-based, relative to holistic, processing mechanisms. Because faces are typically processed holistically, and because social contexts are prime elicitors of emotions, we examined whether negative emotions decrease holistic processing of faces. We induced positive, negative, or neutral emotions via film clips and measured holistic processing before and after the induction: participants made judgements about cued parts of chimeric faces, and holistic processing was indexed by the interference caused by task-irrelevant face parts. Emotional state significantly modulated face-processing style, with the negative emotion induction leading to decreased holistic processing. Furthermore, self-reported change in emotional state correlated with changes in holistic processing. These results contrast with general assumptions that holistic processing of faces is automatic and immune to outside influences, and they illustrate emotion's power to modulate socially relevant aspects of visual perception.

5 CFR 581.203 - Information minimally required to accompany legal process.

Code of Federal Regulations, 2014 CFR

2014-01-01

... accompany legal process. 581.203 Section 581.203 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT... Process § 581.203 Information minimally required to accompany legal process. (a) Sufficient identifying information must accompany the legal process in order to enable processing by the governmental entity named...

5 CFR 581.203 - Information minimally required to accompany legal process.

Code of Federal Regulations, 2011 CFR

2011-01-01

... accompany legal process. 581.203 Section 581.203 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT... Process § 581.203 Information minimally required to accompany legal process. (a) Sufficient identifying information must accompany the legal process in order to enable processing by the governmental entity named...

5 CFR 581.203 - Information minimally required to accompany legal process.

Code of Federal Regulations, 2013 CFR

2013-01-01

... accompany legal process. 581.203 Section 581.203 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT... Process § 581.203 Information minimally required to accompany legal process. (a) Sufficient identifying information must accompany the legal process in order to enable processing by the governmental entity named...

5 CFR 581.203 - Information minimally required to accompany legal process.

Code of Federal Regulations, 2012 CFR

2012-01-01

... accompany legal process. 581.203 Section 581.203 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT... Process § 581.203 Information minimally required to accompany legal process. (a) Sufficient identifying information must accompany the legal process in order to enable processing by the governmental entity named...

5 CFR 581.203 - Information minimally required to accompany legal process.

Code of Federal Regulations, 2010 CFR

2010-01-01

... accompany legal process. 581.203 Section 581.203 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT... Process § 581.203 Information minimally required to accompany legal process. (a) Sufficient identifying information must accompany the legal process in order to enable processing by the governmental entity named...

20 CFR 405.725 - Effect of expedited appeals process agreement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... PROCESS FOR ADJUDICATING INITIAL DISABILITY CLAIMS Expedited Appeals Process for Constitutional Issues § 405.725 Effect of expedited appeals process agreement. After an expedited appeals process agreement is... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Effect of expedited appeals process agreement...

Common and distinct networks for self-referential and social stimulus processing in the human brain.

PubMed

Herold, Dorrit; Spengler, Stephanie; Sajonz, Bastian; Usnich, Tatiana; Bermpohl, Felix

2016-09-01

Self-referential processing is a complex cognitive function, involving a set of implicit and explicit processes, complicating investigation of its distinct neural signature. The present study explores the functional overlap and dissociability of self-referential and social stimulus processing. We combined an established paradigm for explicit self-referential processing with an implicit social stimulus processing paradigm in one fMRI experiment to determine the neural effects of self-relatedness and social processing within one study. Overlapping activations were found in the orbitofrontal cortex and in the intermediate part of the precuneus. Stimuli judged as self-referential specifically activated the posterior cingulate cortex, the ventral medial prefrontal cortex, extending into anterior cingulate cortex and orbitofrontal cortex, the dorsal medial prefrontal cortex, the ventral and dorsal lateral prefrontal cortex, the left inferior temporal gyrus, and occipital cortex. Social processing specifically involved the posterior precuneus and bilateral temporo-parietal junction. Taken together, our data show, not only, first, common networks for both processes in the medial prefrontal and the medial parietal cortex, but also, second, functional differentiations for self-referential processing versus social processing: an anterior-posterior gradient for social processing and self-referential processing within the medial parietal cortex and specific activations for self-referential processing in the medial and lateral prefrontal cortex and for social processing in the temporo-parietal junction.

Using Unified Modelling Language (UML) as a process-modelling technique for clinical-research process improvement.

PubMed

Kumarapeli, P; De Lusignan, S; Ellis, T; Jones, B

2007-03-01

The Primary Care Data Quality programme (PCDQ) is a quality-improvement programme which processes routinely collected general practice computer data. Patient data collected from a wide range of different brands of clinical computer systems are aggregated, processed, and fed back to practices in an educational context to improve the quality of care. Process modelling is a well-established approach used to gain understanding and systematic appraisal, and identify areas of improvement of a business process. Unified modelling language (UML) is a general purpose modelling technique used for this purpose. We used UML to appraise the PCDQ process to see if the efficiency and predictability of the process could be improved. Activity analysis and thinking-aloud sessions were used to collect data to generate UML diagrams. The UML model highlighted the sequential nature of the current process as a barrier for efficiency gains. It also identified the uneven distribution of process controls, lack of symmetric communication channels, critical dependencies among processing stages, and failure to implement all the lessons learned in the piloting phase. It also suggested that improved structured reporting at each stage - especially from the pilot phase, parallel processing of data and correctly positioned process controls - should improve the efficiency and predictability of research projects. Process modelling provided a rational basis for the critical appraisal of a clinical data processing system; its potential maybe underutilized within health care.

Use of Analogies in the Study of Diffusion

ERIC Educational Resources Information Center

Letic, Milorad

2014-01-01

Emergent processes, such as diffusion, are considered more difficult to understand than direct processes. In physiology, most processes are presented as direct processes, so emergent processes, when encountered, are even more difficult to understand. It has been suggested that, when studying diffusion, misconceptions about random processes are the…

Is Analytic Information Processing a Feature of Expertise in Medicine?

ERIC Educational Resources Information Center

McLaughlin, Kevin; Rikers, Remy M.; Schmidt, Henk G.

2008-01-01

Diagnosing begins by generating an initial diagnostic hypothesis by automatic information processing. Information processing may stop here if the hypothesis is accepted, or analytical processing may be used to refine the hypothesis. This description portrays analytic processing as an optional extra in information processing, leading us to…

5 CFR 582.305 - Honoring legal process.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Honoring legal process. 582.305 Section... GARNISHMENT OF FEDERAL EMPLOYEES' PAY Compliance With Legal Process § 582.305 Honoring legal process. (a) The agency shall comply with legal process, except where the process cannot be complied with because: (1) It...

5 CFR 582.305 - Honoring legal process.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Honoring legal process. 582.305 Section... GARNISHMENT OF FEDERAL EMPLOYEES' PAY Compliance With Legal Process § 582.305 Honoring legal process. (a) The agency shall comply with legal process, except where the process cannot be complied with because: (1) It...

5 CFR 581.305 - Honoring legal process.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Honoring legal process. 581.305 Section... GARNISHMENT ORDERS FOR CHILD SUPPORT AND/OR ALIMONY Compliance With Process § 581.305 Honoring legal process. (a) The governmental entity shall comply with legal process, except where the process cannot be...

5 CFR 581.305 - Honoring legal process.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Honoring legal process. 581.305 Section... GARNISHMENT ORDERS FOR CHILD SUPPORT AND/OR ALIMONY Compliance With Process § 581.305 Honoring legal process. (a) The governmental entity shall comply with legal process, except where the process cannot be...

5 CFR 582.305 - Honoring legal process.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Honoring legal process. 582.305 Section... GARNISHMENT OF FEDERAL EMPLOYEES' PAY Compliance With Legal Process § 582.305 Honoring legal process. (a) The agency shall comply with legal process, except where the process cannot be complied with because: (1) It...

5 CFR 581.305 - Honoring legal process.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Honoring legal process. 581.305 Section... GARNISHMENT ORDERS FOR CHILD SUPPORT AND/OR ALIMONY Compliance With Process § 581.305 Honoring legal process. (a) The governmental entity shall comply with legal process, except where the process cannot be...

Articulating the Resources for Business Process Analysis and Design

ERIC Educational Resources Information Center

Jin, Yulong

2012-01-01

Effective process analysis and modeling are important phases of the business process management lifecycle. When many activities and multiple resources are involved, it is very difficult to build a correct business process specification. This dissertation provides a resource perspective of business processes. It aims at a better process analysis…

An Integrated Model of Emotion Processes and Cognition in Social Information Processing.

ERIC Educational Resources Information Center

Lemerise, Elizabeth A.; Arsenio, William F.

2000-01-01

Interprets literature on contributions of social cognitive and emotion processes to children's social competence in the context of an integrated model of emotion processes and cognition in social information processing. Provides neurophysiological and functional evidence for the centrality of emotion processes in personal-social decision making.…

Data Processing and First Products from the Hyperspectral Imager for the Coastal Ocean (HICO) on the International Space Station

DTIC Science & Technology

2010-04-01

NRL Stennis Space Center (NRL-SSC) for further processing using the NRL SSC Automated Processing System (APS). APS was developed for processing...have not previously developed automated processing for 73 hyperspectral ocean color data. The hyperspectral processing branch includes several

DISCRETE COMPOUND POISSON PROCESSES AND TABLES OF THE GEOMETRIC POISSON DISTRIBUTION.

DTIC Science & Technology

A concise summary of the salient properties of discrete Poisson processes , with emphasis on comparing the geometric and logarithmic Poisson processes . The...the geometric Poisson process are given for 176 sets of parameter values. New discrete compound Poisson processes are also introduced. These...processes have properties that are particularly relevant when the summation of several different Poisson processes is to be analyzed. This study provides the

Management of processes of electrochemical dimensional processing

NASA Astrophysics Data System (ADS)

Akhmetov, I. D.; Zakirova, A. R.; Sadykov, Z. B.

2017-09-01

In different industries a lot high-precision parts are produced from hard-processed scarce materials. Forming such details can only be acting during non-contact processing, or a minimum of effort, and doable by the use, for example, of electro-chemical processing. At the present stage of development of metal working processes are important management issues electrochemical machining and its automation. This article provides some indicators and factors of electrochemical machining process.

The Hyperspectral Imager for the Coastal Ocean (HICO): Sensor and Data Processing Overview

DTIC Science & Technology

2010-01-20

backscattering coefficients, and others. Several of these software modules will be developed within the Automated Processing System (APS), a data... Automated Processing System (APS) NRL developed APS, which processes satellite data into ocean color data products. APS is a collection of methods...used for ocean color processing which provide the tools for the automated processing of satellite imagery [1]. These tools are in the process of

[Study on culture and philosophy of processing of traditional Chinese medicines].

PubMed

Yang, Ming; Zhang, Ding-Kun; Zhong, Ling-Yun; Wang, Fang

2013-07-01

According to cultural views and philosophical thoughts, this paper studies the cultural origin, thinking modes, core principles, general regulation and methods of processing, backtracks processing's culture and history which contains generation and deduction process, experienced and promoting process, and core value, summarizes processing's basic principles which are directed by holistic, objective, dynamic, balanced and appropriate thoughts; so as to propagate cultural characteristic and philosophical wisdom of traditional Chinese medicine processing, to promote inheritance and development of processing and to ensure the maximum therapeutic value of Chinese medical clinical.

Containerless automated processing of intermetallic compounds and composites

NASA Technical Reports Server (NTRS)

Johnson, D. R.; Joslin, S. M.; Reviere, R. D.; Oliver, B. F.; Noebe, R. D.

1993-01-01

An automated containerless processing system has been developed to directionally solidify high temperature materials, intermetallic compounds, and intermetallic/metallic composites. The system incorporates a wide range of ultra-high purity chemical processing conditions. The utilization of image processing for automated control negates the need for temperature measurements for process control. The list of recent systems that have been processed includes Cr, Mo, Mn, Nb, Ni, Ti, V, and Zr containing aluminides. Possible uses of the system, process control approaches, and properties and structures of recently processed intermetallics are reviewed.

A continuous process for the development of Kodak Aerochrome Infrared Film 2443 as a negative

NASA Astrophysics Data System (ADS)

Klimes, D.; Ross, D. I.

1993-02-01

A process for the continuous dry-to-dry development of Kodak Aerochrome Infrared Film 2443 as a negative (CIR-neg) is described. The process is well suited for production processing of long film lengths. Chemicals from three commercial film processes are used with modifications. Sensitometric procedures are recommended for the monitoring of processing quality control. Sensitometric data and operational aerial exposures indicate that films developed in this process have approximately the same effective aerial film speed as films processed in the reversal process recommended by the manufacturer (Kodak EA-5). The CIR-neg process is useful when aerial photography is acquired for resources management applications which require print reproductions. Originals can be readily reproduced using conventional production equipment (electronic dodging) in black and white or color (color compensation).

Antibiotics with anaerobic ammonium oxidation in urban wastewater treatment

NASA Astrophysics Data System (ADS)

Zhou, Ruipeng; Yang, Yuanming

2017-05-01

Biofilter process is based on biological oxidation process on the introduction of fast water filter design ideas generated by an integrated filtration, adsorption and biological role of aerobic wastewater treatment process various purification processes. By engineering example, we show that the process is an ideal sewage and industrial wastewater treatment process of low concentration. Anaerobic ammonia oxidation process because of its advantage of the high efficiency and low consumption, wastewater biological denitrification field has broad application prospects. The process in practical wastewater treatment at home and abroad has become a hot spot. In this paper, anammox bacteria habitats and species diversity, and anaerobic ammonium oxidation process in the form of diversity, and one and split the process operating conditions are compared, focusing on a review of the anammox process technology various types of wastewater laboratory research and engineering applications, including general water quality and pressure filtrate sludge digestion, landfill leachate, aquaculture wastewater, monosodium glutamate wastewater, wastewater, sewage, fecal sewage, waste water salinity wastewater characteristics, research progress and application of the obstacles. Finally, we summarize the anaerobic ammonium oxidation process potential problems during the processing of the actual waste water, and proposed future research focus on in-depth study of water quality anammox obstacle factor and its regulatory policy, and vigorously develop on this basis, and combined process optimization.

Understanding scaling through history-dependent processes with collapsing sample space.

PubMed

Corominas-Murtra, Bernat; Hanel, Rudolf; Thurner, Stefan

2015-04-28

History-dependent processes are ubiquitous in natural and social systems. Many such stochastic processes, especially those that are associated with complex systems, become more constrained as they unfold, meaning that their sample space, or their set of possible outcomes, reduces as they age. We demonstrate that these sample-space-reducing (SSR) processes necessarily lead to Zipf's law in the rank distributions of their outcomes. We show that by adding noise to SSR processes the corresponding rank distributions remain exact power laws, p(x) ~ x(-λ), where the exponent directly corresponds to the mixing ratio of the SSR process and noise. This allows us to give a precise meaning to the scaling exponent in terms of the degree to which a given process reduces its sample space as it unfolds. Noisy SSR processes further allow us to explain a wide range of scaling exponents in frequency distributions ranging from α = 2 to ∞. We discuss several applications showing how SSR processes can be used to understand Zipf's law in word frequencies, and how they are related to diffusion processes in directed networks, or aging processes such as in fragmentation processes. SSR processes provide a new alternative to understand the origin of scaling in complex systems without the recourse to multiplicative, preferential, or self-organized critical processes.

Effects of Processing Parameters on the Forming Quality of C-Shaped Thermosetting Composite Laminates in Hot Diaphragm Forming Process

NASA Astrophysics Data System (ADS)

Bian, X. X.; Gu, Y. Z.; Sun, J.; Li, M.; Liu, W. P.; Zhang, Z. G.

2013-10-01

In this study, the effects of processing temperature and vacuum applying rate on the forming quality of C-shaped carbon fiber reinforced epoxy resin matrix composite laminates during hot diaphragm forming process were investigated. C-shaped prepreg preforms were produced using a home-made hot diaphragm forming equipment. The thickness variations of the preforms and the manufacturing defects after diaphragm forming process, including fiber wrinkling and voids, were evaluated to understand the forming mechanism. Furthermore, both interlaminar slipping friction and compaction behavior of the prepreg stacks were experimentally analyzed for showing the importance of the processing parameters. In addition, autoclave processing was used to cure the C-shaped preforms to investigate the changes of the defects before and after cure process. The results show that the C-shaped prepreg preforms with good forming quality can be achieved through increasing processing temperature and reducing vacuum applying rate, which obviously promote prepreg interlaminar slipping process. The process temperature and forming rate in hot diaphragm forming process strongly influence prepreg interply frictional force, and the maximum interlaminar frictional force can be taken as a key parameter for processing parameter optimization. Autoclave process is effective in eliminating voids in the preforms and can alleviate fiber wrinkles to a certain extent.

Assessment of Advanced Coal Gasification Processes

NASA Technical Reports Server (NTRS)

McCarthy, John; Ferrall, Joseph; Charng, Thomas; Houseman, John

1981-01-01

This report represents a technical assessment of the following advanced coal gasification processes: AVCO High Throughput Gasification (HTG) Process; Bell Single-Stage High Mass Flux (HMF) Process; Cities Service/Rockwell (CS/R) Hydrogasification Process; Exxon Catalytic Coal Gasification (CCG) Process. Each process is evaluated for its potential to produce SNG from a bituminous coal. In addition to identifying the new technology these processes represent, key similarities/differences, strengths/weaknesses, and potential improvements to each process are identified. The AVCO HTG and the Bell HMF gasifiers share similarities with respect to: short residence time (SRT), high throughput rate, slagging and syngas as the initial raw product gas. The CS/R Hydrogasifier is also SRT but is non-slagging and produces a raw gas high in methane content. The Exxon CCG gasifier is a long residence time, catalytic, fluidbed reactor producing all of the raw product methane in the gasifier. The report makes the following assessments: 1) while each process has significant potential as coal gasifiers, the CS/R and Exxon processes are better suited for SNG production; 2) the Exxon process is the closest to a commercial level for near-term SNG production; and 3) the SRT processes require significant development including scale-up and turndown demonstration, char processing and/or utilization demonstration, and reactor control and safety features development.

Integrated Process Modeling-A Process Validation Life Cycle Companion.

PubMed

Zahel, Thomas; Hauer, Stefan; Mueller, Eric M; Murphy, Patrick; Abad, Sandra; Vasilieva, Elena; Maurer, Daniel; Brocard, Cécile; Reinisch, Daniela; Sagmeister, Patrick; Herwig, Christoph

2017-10-17

During the regulatory requested process validation of pharmaceutical manufacturing processes, companies aim to identify, control, and continuously monitor process variation and its impact on critical quality attributes (CQAs) of the final product. It is difficult to directly connect the impact of single process parameters (PPs) to final product CQAs, especially in biopharmaceutical process development and production, where multiple unit operations are stacked together and interact with each other. Therefore, we want to present the application of Monte Carlo (MC) simulation using an integrated process model (IPM) that enables estimation of process capability even in early stages of process validation. Once the IPM is established, its capability in risk and criticality assessment is furthermore demonstrated. IPMs can be used to enable holistic production control strategies that take interactions of process parameters of multiple unit operations into account. Moreover, IPMs can be trained with development data, refined with qualification runs, and maintained with routine manufacturing data which underlines the lifecycle concept. These applications will be shown by means of a process characterization study recently conducted at a world-leading contract manufacturing organization (CMO). The new IPM methodology therefore allows anticipation of out of specification (OOS) events, identify critical process parameters, and take risk-based decisions on counteractions that increase process robustness and decrease the likelihood of OOS events.

Effects of rigor status during high-pressure processing on the physical qualities of farm-raised abalone (Haliotis rufescens).

PubMed

Hughes, Brianna H; Greenberg, Neil J; Yang, Tom C; Skonberg, Denise I

2015-01-01

High-pressure processing (HPP) is used to increase meat safety and shelf-life, with conflicting quality effects depending on rigor status during HPP. In the seafood industry, HPP is used to shuck and pasteurize oysters, but its use on abalones has only been minimally evaluated and the effect of rigor status during HPP on abalone quality has not been reported. Farm-raised abalones (Haliotis rufescens) were divided into 12 HPP treatments and 1 unprocessed control treatment. Treatments were processed pre-rigor or post-rigor at 2 pressures (100 and 300 MPa) and 3 processing times (1, 3, and 5 min). The control was analyzed post-rigor. Uniform plugs were cut from adductor and foot meat for texture profile analysis, shear force, and color analysis. Subsamples were used for scanning electron microscopy of muscle ultrastructure. Texture profile analysis revealed that post-rigor processed abalone was significantly (P < 0.05) less firm and chewy than pre-rigor processed irrespective of muscle type, processing time, or pressure. L values increased with pressure to 68.9 at 300 MPa for pre-rigor processed foot, 73.8 for post-rigor processed foot, 90.9 for pre-rigor processed adductor, and 89.0 for post-rigor processed adductor. Scanning electron microscopy images showed fraying of collagen fibers in processed adductor, but did not show pressure-induced compaction of the foot myofibrils. Post-rigor processed abalone meat was more tender than pre-rigor processed meat, and post-rigor processed foot meat was lighter in color than pre-rigor processed foot meat, suggesting that waiting for rigor to resolve prior to processing abalones may improve consumer perceptions of quality and market value. © 2014 Institute of Food Technologists®

PROCESSING ALTERNATIVES FOR DESTRUCTION OF TETRAPHENYLBORATE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lambert, D; Thomas Peters, T; Samuel Fink, S

Two processes were chosen in the 1980's at the Savannah River Site (SRS) to decontaminate the soluble High Level Waste (HLW). The In Tank Precipitation (ITP) process (1,2) was developed at SRS for the removal of radioactive cesium and actinides from the soluble HLW. Sodium tetraphenylborate was added to the waste to precipitate cesium and monosodium titanate (MST) was added to adsorb actinides, primarily uranium and plutonium. Two products of this process were a low activity waste stream and a concentrated organic stream containing cesium tetraphenylborate and actinides adsorbed on monosodium titanate (MST). A copper catalyzed acid hydrolysis process wasmore » built to process (3, 4) the Tank 48H cesium tetraphenylborate waste in the SRS's Defense Waste Processing Facility (DWPF). Operation of the DWPF would have resulted in the production of benzene for incineration in SRS's Consolidated Incineration Facility. This process was abandoned together with the ITP process in 1998 due to high benzene in ITP caused by decomposition of excess sodium tetraphenylborate. Processing in ITP resulted in the production of approximately 1.0 million liters of HLW. SRS has chosen a solvent extraction process combined with adsorption of the actinides to decontaminate the soluble HLW stream (5). However, the waste in Tank 48H is incompatible with existing waste processing facilities. As a result, a processing facility is needed to disposition the HLW in Tank 48H. This paper will describe the process for searching for processing options by SRS task teams for the disposition of the waste in Tank 48H. In addition, attempts to develop a caustic hydrolysis process for in tank destruction of tetraphenylborate will be presented. Lastly, the development of both a caustic and acidic copper catalyzed peroxide oxidation process will be discussed.« less

Manufacturing Process Selection of Composite Bicycle’s Crank Arm using Analytical Hierarchy Process (AHP)

NASA Astrophysics Data System (ADS)

Luqman, M.; Rosli, M. U.; Khor, C. Y.; Zambree, Shayfull; Jahidi, H.

2018-03-01

Crank arm is one of the important parts in a bicycle that is an expensive product due to the high cost of material and production process. This research is aimed to investigate the potential type of manufacturing process to fabricate composite bicycle crank arm and to describe an approach based on analytical hierarchy process (AHP) that assists decision makers or manufacturing engineers in determining the most suitable process to be employed in manufacturing of composite bicycle crank arm at the early stage of the product development process to reduce the production cost. There are four types of processes were considered, namely resin transfer molding (RTM), compression molding (CM), vacuum bag molding and filament winding (FW). The analysis ranks these four types of process for its suitability in the manufacturing of bicycle crank arm based on five main selection factors and 10 sub factors. Determining the right manufacturing process was performed based on AHP process steps. Consistency test was performed to make sure the judgements are consistent during the comparison. The results indicated that the compression molding was the most appropriate manufacturing process because it has the highest value (33.6%) among the other manufacturing processes.

A System-Oriented Approach for the Optimal Control of Process Chains under Stochastic Influences

NASA Astrophysics Data System (ADS)

Senn, Melanie; Schäfer, Julian; Pollak, Jürgen; Link, Norbert

2011-09-01

Process chains in manufacturing consist of multiple connected processes in terms of dynamic systems. The properties of a product passing through such a process chain are influenced by the transformation of each single process. There exist various methods for the control of individual processes, such as classical state controllers from cybernetics or function mapping approaches realized by statistical learning. These controllers ensure that a desired state is obtained at process end despite of variations in the input and disturbances. The interactions between the single processes are thereby neglected, but play an important role in the optimization of the entire process chain. We divide the overall optimization into two phases: (1) the solution of the optimization problem by Dynamic Programming to find the optimal control variable values for each process for any encountered end state of its predecessor and (2) the application of the optimal control variables at runtime for the detected initial process state. The optimization problem is solved by selecting adequate control variables for each process in the chain backwards based on predefined quality requirements for the final product. For the demonstration of the proposed concept, we have chosen a process chain from sheet metal manufacturing with simplified transformation functions.

Quantitative analysis of geomorphic processes using satellite image data at different scales

NASA Technical Reports Server (NTRS)

Williams, R. S., Jr.

1985-01-01

When aerial and satellite photographs and images are used in the quantitative analysis of geomorphic processes, either through direct observation of active processes or by analysis of landforms resulting from inferred active or dormant processes, a number of limitations in the use of such data must be considered. Active geomorphic processes work at different scales and rates. Therefore, the capability of imaging an active or dormant process depends primarily on the scale of the process and the spatial-resolution characteristic of the imaging system. Scale is an important factor in recording continuous and discontinuous active geomorphic processes, because what is not recorded will not be considered or even suspected in the analysis of orbital images. If the geomorphic process of landform change caused by the process is less than 200 m in x to y dimension, then it will not be recorded. Although the scale factor is critical, in the recording of discontinuous active geomorphic processes, the repeat interval of orbital-image acquisition of a planetary surface also is a consideration in order to capture a recurring short-lived geomorphic process or to record changes caused by either a continuous or a discontinuous geomorphic process.

Remote Sensing Image Quality Assessment Experiment with Post-Processing

NASA Astrophysics Data System (ADS)

Jiang, W.; Chen, S.; Wang, X.; Huang, Q.; Shi, H.; Man, Y.

2018-04-01

This paper briefly describes the post-processing influence assessment experiment, the experiment includes three steps: the physical simulation, image processing, and image quality assessment. The physical simulation models sampled imaging system in laboratory, the imaging system parameters are tested, the digital image serving as image processing input are produced by this imaging system with the same imaging system parameters. The gathered optical sampled images with the tested imaging parameters are processed by 3 digital image processes, including calibration pre-processing, lossy compression with different compression ratio and image post-processing with different core. Image quality assessment method used is just noticeable difference (JND) subject assessment based on ISO20462, through subject assessment of the gathered and processing images, the influence of different imaging parameters and post-processing to image quality can be found. The six JND subject assessment experimental data can be validated each other. Main conclusions include: image post-processing can improve image quality; image post-processing can improve image quality even with lossy compression, image quality with higher compression ratio improves less than lower ratio; with our image post-processing method, image quality is better, when camera MTF being within a small range.

Microstructure and Texture of Al-2.5wt.%Mg Processed by Combining Accumulative Roll Bonding and Conventional Rolling

NASA Astrophysics Data System (ADS)

Gatti, J. R.; Bhattacharjee, P. P.

2014-12-01

Evolution of microstructure and texture during severe deformation and annealing was studied in Al-2.5%Mg alloy processed by two different routes, namely, monotonic Accumulative Roll Bonding (ARB) and a hybrid route combining ARB and conventional rolling (CR). For this purpose Al-2.5%Mg sheets were subjected to 5 cycles of monotonic ARB (equivalent strain (ɛeq) = 4.0) processing while in the hybrid route (ARB + CR) 3 cycle ARB-processed sheets were further deformed by conventional rolling to 75% reduction in thickness (ɛeq = 4.0). Although formation of ultrafine structure was observed in the two processing routes, the monotonic ARB—processed material showed finer microstructure but weak texture as compared to the ARB + CR—processed material. After complete recrystallization, the ARB + CR-processed material showed weak cube texture ({001}<100>) but the cube component was almost negligible in the monotonic ARB-processed material-processed material. However, the ND-rotated cube components were stronger in the monotonic ARB-processed material-processed material. The observed differences in the microstructure and texture evolution during deformation and annealing could be explained by the characteristic differences of the two processing routes.

Process Materialization Using Templates and Rules to Design Flexible Process Models

NASA Astrophysics Data System (ADS)

Kumar, Akhil; Yao, Wen

The main idea in this paper is to show how flexible processes can be designed by combining generic process templates and business rules. We instantiate a process by applying rules to specific case data, and running a materialization algorithm. The customized process instance is then executed in an existing workflow engine. We present an architecture and also give an algorithm for process materialization. The rules are written in a logic-based language like Prolog. Our focus is on capturing deeper process knowledge and achieving a holistic approach to robust process design that encompasses control flow, resources and data, as well as makes it easier to accommodate changes to business policy.

HMI conventions for process control graphics.

PubMed

Pikaar, Ruud N

2012-01-01

Process operators supervise and control complex processes. To enable the operator to do an adequate job, instrumentation and process control engineers need to address several related topics, such as console design, information design, navigation, and alarm management. In process control upgrade projects, usually a 1:1 conversion of existing graphics is proposed. This paper suggests another approach, efficiently leading to a reduced number of new powerful process graphics, supported by a permanent process overview displays. In addition a road map for structuring content (process information) and conventions for the presentation of objects, symbols, and so on, has been developed. The impact of the human factors engineering approach on process control upgrade projects is illustrated by several cases.

A novel processed food classification system applied to Australian food composition databases.

PubMed

O'Halloran, S A; Lacy, K E; Grimes, C A; Woods, J; Campbell, K J; Nowson, C A

2017-08-01

The extent of food processing can affect the nutritional quality of foodstuffs. Categorising foods by the level of processing emphasises the differences in nutritional quality between foods within the same food group and is likely useful for determining dietary processed food consumption. The present study aimed to categorise foods within Australian food composition databases according to the level of food processing using a processed food classification system, as well as assess the variation in the levels of processing within food groups. A processed foods classification system was applied to food and beverage items contained within Australian Food and Nutrient (AUSNUT) 2007 (n = 3874) and AUSNUT 2011-13 (n = 5740). The proportion of Minimally Processed (MP), Processed Culinary Ingredients (PCI) Processed (P) and Ultra Processed (ULP) by AUSNUT food group and the overall proportion of the four processed food categories across AUSNUT 2007 and AUSNUT 2011-13 were calculated. Across the food composition databases, the overall proportions of foods classified as MP, PCI, P and ULP were 27%, 3%, 26% and 44% for AUSNUT 2007 and 38%, 2%, 24% and 36% for AUSNUT 2011-13. Although there was wide variation in the classifications of food processing within the food groups, approximately one-third of foodstuffs were classified as ULP food items across both the 2007 and 2011-13 AUSNUT databases. This Australian processed food classification system will allow researchers to easily quantify the contribution of processed foods within the Australian food supply to assist in assessing the nutritional quality of the dietary intake of population groups. © 2017 The British Dietetic Association Ltd.

Process and domain specificity in regions engaged for face processing: an fMRI study of perceptual differentiation.

PubMed

Collins, Heather R; Zhu, Xun; Bhatt, Ramesh S; Clark, Jonathan D; Joseph, Jane E

2012-12-01

The degree to which face-specific brain regions are specialized for different kinds of perceptual processing is debated. This study parametrically varied demands on featural, first-order configural, or second-order configural processing of faces and houses in a perceptual matching task to determine the extent to which the process of perceptual differentiation was selective for faces regardless of processing type (domain-specific account), specialized for specific types of perceptual processing regardless of category (process-specific account), engaged in category-optimized processing (i.e., configural face processing or featural house processing), or reflected generalized perceptual differentiation (i.e., differentiation that crosses category and processing type boundaries). ROIs were identified in a separate localizer run or with a similarity regressor in the face-matching runs. The predominant principle accounting for fMRI signal modulation in most regions was generalized perceptual differentiation. Nearly all regions showed perceptual differentiation for both faces and houses for more than one processing type, even if the region was identified as face-preferential in the localizer run. Consistent with process specificity, some regions showed perceptual differentiation for first-order processing of faces and houses (right fusiform face area and occipito-temporal cortex and right lateral occipital complex), but not for featural or second-order processing. Somewhat consistent with domain specificity, the right inferior frontal gyrus showed perceptual differentiation only for faces in the featural matching task. The present findings demonstrate that the majority of regions involved in perceptual differentiation of faces are also involved in differentiation of other visually homogenous categories.

Process- and Domain-Specificity in Regions Engaged for Face Processing: An fMRI Study of Perceptual Differentiation

PubMed Central

Collins, Heather R.; Zhu, Xun; Bhatt, Ramesh S.; Clark, Jonathan D.; Joseph, Jane E.

2015-01-01

The degree to which face-specific brain regions are specialized for different kinds of perceptual processing is debated. The present study parametrically varied demands on featural, first-order configural or second-order configural processing of faces and houses in a perceptual matching task to determine the extent to which the process of perceptual differentiation was selective for faces regardless of processing type (domain-specific account), specialized for specific types of perceptual processing regardless of category (process-specific account), engaged in category-optimized processing (i.e., configural face processing or featural house processing) or reflected generalized perceptual differentiation (i.e. differentiation that crosses category and processing type boundaries). Regions of interest were identified in a separate localizer run or with a similarity regressor in the face-matching runs. The predominant principle accounting for fMRI signal modulation in most regions was generalized perceptual differentiation. Nearly all regions showed perceptual differentiation for both faces and houses for more than one processing type, even if the region was identified as face-preferential in the localizer run. Consistent with process-specificity, some regions showed perceptual differentiation for first-order processing of faces and houses (right fusiform face area and occipito-temporal cortex, and right lateral occipital complex), but not for featural or second-order processing. Somewhat consistent with domain-specificity, the right inferior frontal gyrus showed perceptual differentiation only for faces in the featural matching task. The present findings demonstrate that the majority of regions involved in perceptual differentiation of faces are also involved in differentiation of other visually homogenous categories. PMID:22849402

Achieving Continuous Manufacturing for Final Dosage Formation: Challenges and How to Meet Them May 20-21 2014 Continuous Manufacturing Symposium.

PubMed

Byrn, Stephen; Futran, Maricio; Thomas, Hayden; Jayjock, Eric; Maron, Nicola; Meyer, Robert F; Myerson, Allan S; Thien, Michael P; Trout, Bernhardt L

2015-03-01

We describe the key issues and possibilities for continuous final dosage formation, otherwise known as downstream processing or drug product manufacturing. A distinction is made between heterogeneous processing and homogeneous processing, the latter of which is expected to add more value to continuous manufacturing. We also give the key motivations for moving to continuous manufacturing, some of the exciting new technologies, and the barriers to implementation of continuous manufacturing. Continuous processing of heterogeneous blends is the natural first step in converting existing batch processes to continuous. In heterogeneous processing, there are discrete particles that can segregate, versus in homogeneous processing, components are blended and homogenized such that they do not segregate. Heterogeneous processing can incorporate technologies that are closer to existing technologies, where homogeneous processing necessitates the development and incorporation of new technologies. Homogeneous processing has the greatest potential for reaping the full rewards of continuous manufacturing, but it takes long-term vision and a more significant change in process development than heterogeneous processing. Heterogeneous processing has the detriment that, as the technologies are adopted rather than developed, there is a strong tendency to incorporate correction steps, what we call below "The Rube Goldberg Problem." Thus, although heterogeneous processing will likely play a major role in the near-term transformation of heterogeneous to continuous processing, it is expected that homogeneous processing is the next step that will follow. Specific action items for industry leaders are. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

An Analysis of the Air Force Government Operated Civil Engineering Supply Store Logistic System: How Can It Be Improved?

DTIC Science & Technology

1990-09-01

6 Logistics Systems ............ 7 GOCESS Operation . . . . . . . ..... 9 Work Order Processing . . . . ... 12 Job Order Processing . . . . . . . . . . 14...orders and job orders to the Material Control Section will be discussed separately. Work Order Processing . Figure 2 illustrates typical WO processing...logistics function. The JO processing is similar. Job Order Processing . Figure 3 illustrates typical JO processing in a GOCESS operation. As with WOs, this

Adaptive-optics optical coherence tomography processing using a graphics processing unit.

PubMed

Shafer, Brandon A; Kriske, Jeffery E; Kocaoglu, Omer P; Turner, Timothy L; Liu, Zhuolin; Lee, John Jaehwan; Miller, Donald T

2014-01-01

Graphics processing units are increasingly being used for scientific computing for their powerful parallel processing abilities, and moderate price compared to super computers and computing grids. In this paper we have used a general purpose graphics processing unit to process adaptive-optics optical coherence tomography (AOOCT) images in real time. Increasing the processing speed of AOOCT is an essential step in moving the super high resolution technology closer to clinical viability.

Data processing system for the Sneg-2MP experiment

NASA Technical Reports Server (NTRS)

Gavrilova, Y. A.

1980-01-01

The data processing system for scientific experiments on stations of the "Prognoz" type provides for the processing sequence to be broken down into a number of consecutive stages: preliminary processing, primary processing, secondary processing. The tasks of each data processing stage are examined for an experiment designed to study gamma flashes of galactic origin and solar flares lasting from several minutes to seconds in the 20 kev to 1000 kev energy range.

General RMP Guidance - Appendix D: OSHA Guidance on PSM

EPA Pesticide Factsheets

OSHA's Process Safety Management (PSM) Guidance on providing complete and accurate written information concerning process chemicals, process technology, and process equipment; including process hazard analysis and material safety data sheets.

Elaboration Likelihood and the Counseling Process: The Role of Affect.

ERIC Educational Resources Information Center

Stoltenberg, Cal D.; And Others

The role of affect in counseling has been examined from several orientations. The depth of processing model views the efficiency of information processing as a function of the extent to which the information is processed. The notion of cognitive processing capacity states that processing information at deeper levels engages more of one's limited…

5 CFR 582.202 - Service of legal process.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Service of legal process. 582.202 Section... GARNISHMENT OF FEDERAL EMPLOYEES' PAY Service of Legal Process § 582.202 Service of legal process. (a) A person using this part shall serve interrogatories and legal process on the agent to receive process as...

5 CFR 582.202 - Service of legal process.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Service of legal process. 582.202 Section... GARNISHMENT OF FEDERAL EMPLOYEES' PAY Service of Legal Process § 582.202 Service of legal process. (a) A person using this part shall serve interrogatories and legal process on the agent to receive process as...

Information Processing Concepts: A Cure for "Technofright." Information Processing in the Electronic Office. Part 1: Concepts.

ERIC Educational Resources Information Center

Popyk, Marilyn K.

1986-01-01

Discusses the new automated office and its six major technologies (data processing, word processing, graphics, image, voice, and networking), the information processing cycle (input, processing, output, distribution/communication, and storage and retrieval), ergonomics, and ways to expand office education classes (versus class instruction). (CT)

Facial Speech Gestures: The Relation between Visual Speech Processing, Phonological Awareness, and Developmental Dyslexia in 10-Year-Olds

ERIC Educational Resources Information Center

Schaadt, Gesa; Männel, Claudia; van der Meer, Elke; Pannekamp, Ann; Friederici, Angela D.

2016-01-01

Successful communication in everyday life crucially involves the processing of auditory and visual components of speech. Viewing our interlocutor and processing visual components of speech facilitates speech processing by triggering auditory processing. Auditory phoneme processing, analyzed by event-related brain potentials (ERP), has been shown…

40 CFR 65.62 - Process vent group determination.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., or Group 2B) for each process vent. Group 1 process vents require control, and Group 2A and 2B... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Process vent group determination. 65... (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Process Vents § 65.62 Process vent group determination. (a) Group...

40 CFR 63.138 - Process wastewater provisions-performance standards for treatment processes managing Group 1...

Code of Federal Regulations, 2010 CFR

2010-07-01

.../or Table 9 compounds are similar and often identical. (3) Biological treatment processes. Biological treatment processes in compliance with this section may be either open or closed biological treatment processes as defined in § 63.111. An open biological treatment process in compliance with this section need...

5 CFR 581.202 - Service of process.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Service of process. 581.202 Section 581... GARNISHMENT ORDERS FOR CHILD SUPPORT AND/OR ALIMONY Service of Process § 581.202 Service of process. (a) A... facilitate proper service of process on its designated agent(s). If legal process is not directed to any...

30 CFR 828.11 - In situ processing: Performance standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 3 2011-07-01 2011-07-01 false In situ processing: Performance standards. 828... STANDARDS-IN SITU PROCESSING § 828.11 In situ processing: Performance standards. (a) The person who conducts in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing...

30 CFR 828.11 - In situ processing: Performance standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 3 2012-07-01 2012-07-01 false In situ processing: Performance standards. 828... STANDARDS-IN SITU PROCESSING § 828.11 In situ processing: Performance standards. (a) The person who conducts in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing...

30 CFR 828.11 - In situ processing: Performance standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 3 2013-07-01 2013-07-01 false In situ processing: Performance standards. 828... STANDARDS-IN SITU PROCESSING § 828.11 In situ processing: Performance standards. (a) The person who conducts in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing...

30 CFR 828.11 - In situ processing: Performance standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 3 2010-07-01 2010-07-01 false In situ processing: Performance standards. 828... STANDARDS-IN SITU PROCESSING § 828.11 In situ processing: Performance standards. (a) The person who conducts in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing...

30 CFR 828.11 - In situ processing: Performance standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 3 2014-07-01 2014-07-01 false In situ processing: Performance standards. 828... STANDARDS-IN SITU PROCESSING § 828.11 In situ processing: Performance standards. (a) The person who conducts in situ processing activities shall comply with 30 CFR 817 and this section. (b) In situ processing...

Processing Depth, Elaboration of Encoding, Memory Stores, and Expended Processing Capacity.

ERIC Educational Resources Information Center

Eysenck, Michael W.; Eysenck, M. Christine

1979-01-01

The effects of several factors on expended processing capacity were measured. Expended processing capacity was greater when information was retrieved from secondary memory than from primary memory, when processing was of a deep, semantic nature than when it was shallow and physical, and when processing was more elaborate. (Author/GDC)

Speed isn’t everything: Complex processing speed measures mask individual differences and developmental changes in executive control

PubMed Central

Cepeda, Nicholas J.; Blackwell, Katharine A.; Munakata, Yuko

2012-01-01

The rate at which people process information appears to influence many aspects of cognition across the lifespan. However, many commonly accepted measures of “processing speed” may require goal maintenance, manipulation of information in working memory, and decision-making, blurring the distinction between processing speed and executive control and resulting in overestimation of processing-speed contributions to cognition. This concern may apply particularly to studies of developmental change, as even seemingly simple processing speed measures may require executive processes to keep children and older adults on task. We report two new studies and a re-analysis of a published study, testing predictions about how different processing speed measures influence conclusions about executive control across the life span. We find that the choice of processing speed measure affects the relationship observed between processing speed and executive control, in a manner that changes with age, and that choice of processing speed measure affects conclusions about development and the relationship among executive control measures. Implications for understanding processing speed, executive control, and their development are discussed. PMID:23432836

The impact of working memory and the “process of process modelling” on model quality: Investigating experienced versus inexperienced modellers

NASA Astrophysics Data System (ADS)

Martini, Markus; Pinggera, Jakob; Neurauter, Manuel; Sachse, Pierre; Furtner, Marco R.; Weber, Barbara

2016-05-01

A process model (PM) represents the graphical depiction of a business process, for instance, the entire process from online ordering a book until the parcel is delivered to the customer. Knowledge about relevant factors for creating PMs of high quality is lacking. The present study investigated the role of cognitive processes as well as modelling processes in creating a PM in experienced and inexperienced modellers. Specifically, two working memory (WM) functions (holding and processing of information and relational integration) and three process of process modelling phases (comprehension, modelling, and reconciliation) were related to PM quality. Our results show that the WM function of relational integration was positively related to PM quality in both modelling groups. The ratio of comprehension phases was negatively related to PM quality in inexperienced modellers and the ratio of reconciliation phases was positively related to PM quality in experienced modellers. Our research reveals central cognitive mechanisms in process modelling and has potential practical implications for the development of modelling software and teaching the craft of process modelling.

A new class of random processes with application to helicopter noise

NASA Technical Reports Server (NTRS)

Hardin, Jay C.; Miamee, A. G.

1989-01-01

The concept of dividing random processes into classes (e.g., stationary, locally stationary, periodically correlated, and harmonizable) has long been employed. A new class of random processes is introduced which includes many of these processes as well as other interesting processes which fall into none of the above classes. Such random processes are denoted as linearly correlated. This class is shown to include the familiar stationary and periodically correlated processes as well as many other, both harmonizable and non-harmonizable, nonstationary processes. When a process is linearly correlated for all t and harmonizable, its two-dimensional power spectral density S(x) (omega 1, omega 2) is shown to take a particularly simple form, being non-zero only on lines such that omega 1 to omega 2 = + or - r(k) where the r(k's) are (not necessarily equally spaced) roots of a characteristic function. The relationship of such processes to the class of stationary processes is examined. In addition, the application of such processes in the analysis of typical helicopter noise signals is described.

The impact of working memory and the “process of process modelling” on model quality: Investigating experienced versus inexperienced modellers

PubMed Central

Martini, Markus; Pinggera, Jakob; Neurauter, Manuel; Sachse, Pierre; Furtner, Marco R.; Weber, Barbara

2016-01-01

A process model (PM) represents the graphical depiction of a business process, for instance, the entire process from online ordering a book until the parcel is delivered to the customer. Knowledge about relevant factors for creating PMs of high quality is lacking. The present study investigated the role of cognitive processes as well as modelling processes in creating a PM in experienced and inexperienced modellers. Specifically, two working memory (WM) functions (holding and processing of information and relational integration) and three process of process modelling phases (comprehension, modelling, and reconciliation) were related to PM quality. Our results show that the WM function of relational integration was positively related to PM quality in both modelling groups. The ratio of comprehension phases was negatively related to PM quality in inexperienced modellers and the ratio of reconciliation phases was positively related to PM quality in experienced modellers. Our research reveals central cognitive mechanisms in process modelling and has potential practical implications for the development of modelling software and teaching the craft of process modelling. PMID:27157858

A new class of random processes with application to helicopter noise

NASA Technical Reports Server (NTRS)

Hardin, Jay C.; Miamee, A. G.

1989-01-01

The concept of dividing random processes into classes (e.g., stationary, locally stationary, periodically correlated, and harmonizable) has long been employed. A new class of random processes is introduced which includes many of these processes as well as other interesting processes which fall into none of the above classes. Such random processes are denoted as linearly correlated. This class is shown to include the familiar stationary and periodically correlated processes as well as many other, both harmonizable and non-harmonizable, nonstationary processes. When a process is linearly correlated for all t and harmonizable, its two-dimensional power spectral density S(x)(omega 1, omega 2) is shown to take a particularly simple form, being non-zero only on lines such that omega 1 to omega 2 = + or - r(k) where the r(k's) are (not necessarily equally spaced) roots of a characteristic function. The relationship of such processes to the class of stationary processes is examined. In addition, the application of such processes in the analysis of typical helicopter noise signals is described.

The impact of working memory and the "process of process modelling" on model quality: Investigating experienced versus inexperienced modellers.

PubMed

Martini, Markus; Pinggera, Jakob; Neurauter, Manuel; Sachse, Pierre; Furtner, Marco R; Weber, Barbara

2016-05-09

A process model (PM) represents the graphical depiction of a business process, for instance, the entire process from online ordering a book until the parcel is delivered to the customer. Knowledge about relevant factors for creating PMs of high quality is lacking. The present study investigated the role of cognitive processes as well as modelling processes in creating a PM in experienced and inexperienced modellers. Specifically, two working memory (WM) functions (holding and processing of information and relational integration) and three process of process modelling phases (comprehension, modelling, and reconciliation) were related to PM quality. Our results show that the WM function of relational integration was positively related to PM quality in both modelling groups. The ratio of comprehension phases was negatively related to PM quality in inexperienced modellers and the ratio of reconciliation phases was positively related to PM quality in experienced modellers. Our research reveals central cognitive mechanisms in process modelling and has potential practical implications for the development of modelling software and teaching the craft of process modelling.

Rapid Automatized Naming in Children with Dyslexia: Is Inhibitory Control Involved?

PubMed

Bexkens, Anika; van den Wildenberg, Wery P M; Tijms, Jurgen

2015-08-01

Rapid automatized naming (RAN) is widely seen as an important indicator of dyslexia. The nature of the cognitive processes involved in rapid naming is however still a topic of controversy. We hypothesized that in addition to the involvement of phonological processes and processing speed, RAN is a function of inhibition processes, in particular of interference control. A total 86 children with dyslexia and 31 normal readers were recruited. Our results revealed that in addition to phonological processing and processing speed, interference control predicts rapid naming in dyslexia, but in contrast to these other two cognitive processes, inhibition is not significantly associated with their reading and spelling skills. After variance in reading and spelling associated with processing speed, interference control and phonological processing was partialled out, naming speed was no longer consistently associated with the reading and spelling skills of children with dyslexia. Finally, dyslexic children differed from normal readers on naming speed, literacy skills, phonological processing and processing speed, but not on inhibition processes. Both theoretical and clinical interpretations of these results are discussed. Copyright © 2014 John Wiley & Sons, Ltd.

Feasibility of using continuous chromatography in downstream processing: Comparison of costs and product quality for a hybrid process vs. a conventional batch process.

PubMed

Ötes, Ozan; Flato, Hendrik; Winderl, Johannes; Hubbuch, Jürgen; Capito, Florian

2017-10-10

The protein A capture step is the main cost-driver in downstream processing, with high attrition costs especially when using protein A resin not until end of resin lifetime. Here we describe a feasibility study, transferring a batch downstream process to a hybrid process, aimed at replacing batch protein A capture chromatography with a continuous capture step, while leaving the polishing steps unchanged to minimize required process adaptations compared to a batch process. 35g of antibody were purified using the hybrid approach, resulting in comparable product quality and step yield compared to the batch process. Productivity for the protein A step could be increased up to 420%, reducing buffer amounts by 30-40% and showing robustness for at least 48h continuous run time. Additionally, to enable its potential application in a clinical trial manufacturing environment cost of goods were compared for the protein A step between hybrid process and batch process, showing a 300% cost reduction, depending on processed volumes and batch cycles. Copyright © 2017 Elsevier B.V. All rights reserved.

Non-Conscious Perception of Emotions in Psychiatric Disorders: The Unsolved Puzzle of Psychopathology.

PubMed

Lee, Seung A; Kim, Chai-Youn; Lee, Seung-Hwan

2016-03-01

Psychophysiological and functional neuroimaging studies have frequently and consistently shown that emotional information can be processed outside of the conscious awareness. Non-conscious processing comprises automatic, uncontrolled, and fast processing that occurs without subjective awareness. However, how such non-conscious emotional processing occurs in patients with various psychiatric disorders requires further examination. In this article, we reviewed and discussed previous studies on the non-conscious emotional processing in patients diagnosed with anxiety disorder, schizophrenia, bipolar disorder, and depression, to further understand how non-conscious emotional processing varies across these psychiatric disorders. Although the symptom profile of each disorder does not often overlap with one another, these patients commonly show abnormal emotional processing based on the pathology of their mood and cognitive function. This indicates that the observed abnormalities of emotional processing in certain social interactions may derive from a biased mood or cognition process that precedes consciously controlled and voluntary processes. Since preconscious forms of emotional processing appear to have a major effect on behaviour and cognition in patients with these disorders, further investigation is required to understand these processes and their impact on patient pathology.

Empirical evaluation of the Process Overview Measure for assessing situation awareness in process plants.

PubMed

Lau, Nathan; Jamieson, Greg A; Skraaning, Gyrd

2016-03-01

The Process Overview Measure is a query-based measure developed to assess operator situation awareness (SA) from monitoring process plants. A companion paper describes how the measure has been developed according to process plant properties and operator cognitive work. The Process Overview Measure demonstrated practicality, sensitivity, validity and reliability in two full-scope simulator experiments investigating dramatically different operational concepts. Practicality was assessed based on qualitative feedback of participants and researchers. The Process Overview Measure demonstrated sensitivity and validity by revealing significant effects of experimental manipulations that corroborated with other empirical results. The measure also demonstrated adequate inter-rater reliability and practicality for measuring SA in full-scope simulator settings based on data collected on process experts. Thus, full-scope simulator studies can employ the Process Overview Measure to reveal the impact of new control room technology and operational concepts on monitoring process plants. Practitioner Summary: The Process Overview Measure is a query-based measure that demonstrated practicality, sensitivity, validity and reliability for assessing operator situation awareness (SA) from monitoring process plants in representative settings.

A Framework for Business Process Change Requirements Analysis

NASA Astrophysics Data System (ADS)

Grover, Varun; Otim, Samuel

The ability to quickly and continually adapt business processes to accommodate evolving requirements and opportunities is critical for success in competitive environments. Without appropriate linkage between redesign decisions and strategic inputs, identifying processes that need to be modified will be difficult. In this paper, we draw attention to the analysis of business process change requirements in support of process change initiatives. Business process redesign is a multifaceted phenomenon involving processes, organizational structure, management systems, human resource architecture, and many other aspects of organizational life. To be successful, the business process initiative should focus not only on identifying the processes to be redesigned, but also pay attention to various enablers of change. Above all, a framework is just a blueprint; management must lead change. We hope our modest contribution will draw attention to the broader framing of requirements for business process change.

Process Analytical Technology (PAT): batch-to-batch reproducibility of fermentation processes by robust process operational design and control.

PubMed

Gnoth, S; Jenzsch, M; Simutis, R; Lübbert, A

2007-10-31

The Process Analytical Technology (PAT) initiative of the FDA is a reaction on the increasing discrepancy between current possibilities in process supervision and control of pharmaceutical production processes and its current application in industrial manufacturing processes. With rigid approval practices based on standard operational procedures, adaptations of production reactors towards the state of the art were more or less inhibited for long years. Now PAT paves the way for continuous process and product improvements through improved process supervision based on knowledge-based data analysis, "Quality-by-Design"-concepts, and, finally, through feedback control. Examples of up-to-date implementations of this concept are presented. They are taken from one key group of processes in recombinant pharmaceutical protein manufacturing, the cultivations of genetically modified Escherichia coli bacteria.

When teams shift among processes: insights from simulation and optimization.

PubMed

Kennedy, Deanna M; McComb, Sara A

2014-09-01

This article introduces process shifts to study the temporal interplay among transition and action processes espoused in the recurring phase model proposed by Marks, Mathieu, and Zacarro (2001). Process shifts are those points in time when teams complete a focal process and change to another process. By using team communication patterns to measure process shifts, this research explores (a) when teams shift among different transition processes and initiate action processes and (b) the potential of different interventions, such as communication directives, to manipulate process shift timing and order and, ultimately, team performance. Virtual experiments are employed to compare data from observed laboratory teams not receiving interventions, simulated teams receiving interventions, and optimal simulated teams generated using genetic algorithm procedures. Our results offer insights about the potential for different interventions to affect team performance. Moreover, certain interventions may promote discussions about key issues (e.g., tactical strategies) and facilitate shifting among transition processes in a manner that emulates optimal simulated teams' communication patterns. Thus, we contribute to theory regarding team processes in 2 important ways. First, we present process shifts as a way to explore the timing of when teams shift from transition to action processes. Second, we use virtual experimentation to identify those interventions with the greatest potential to affect performance by changing when teams shift among processes. Additionally, we employ computational methods including neural networks, simulation, and optimization, thereby demonstrating their applicability in conducting team research. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Nitrous oxide and methane emissions from different treatment processes in full-scale municipal wastewater treatment plants.

PubMed

Rena, Y G; Wang, J H; Li, H F; Zhang, J; Qi, P Y; Hu, Z

2013-01-01

Nitrous oxide (N2O) and methane (CH4) are two important greenhouse gases (GHG) emitted from biological nutrient removal (BNR) processes in municipal wastewater treatment plants (WWTP). In this study, three typical biological wastewater treatment processes were studied in WWTP of Northern China: pre-anaerobic carrousel oxidation ditch (A+OD) process, pre-anoxic anaerobic-anoxic-oxic (A-A/ A/O) process and reverse anaerobic-anoxic-oxic (r-A/ A/O) process. The N2O and CH4 emissions from these three different processes were measured in every processing unit of each WWTP. Results showed that N2O and CH4 were mainly discharged during the nitrification/denitrification process and the anaerobic/anoxic treatment process, respectively and the amounts of their formation and release were significantly influenced by different BNR processes implemented in these WWTP. The N2O conversion ratio of r-A/ A/O process was the lowest among the three WWTP, which were 10.9% and 18.6% lower than that of A-A/A/O process and A+OD process, respectively. Similarly, the CH4 conversion ratio of r-A/ A/O process was the lowest among the three WWTP, which were 89. I% and 80.8% lower than that of A-A/ A/O process and A+OD process, respectively. The factors influencing N2O and CH4 formation and emission in the three WWTP were investigated to explain the difference between these processes. The nitrite concentration and oxidation-reduction potential (ORP) value were found to be the dominant influencing factors affecting N2O and CH4 production, respectively. The flow-based emission factors of N2O and CH4 of the WWTP were figured out for better quantification of GHG emissions and further technical assessments of mitigation options.

Effects of children's working memory capacity and processing speed on their sentence imitation performance.

PubMed

Poll, Gerard H; Miller, Carol A; Mainela-Arnold, Elina; Adams, Katharine Donnelly; Misra, Maya; Park, Ji Sook

2013-01-01

More limited working memory capacity and slower processing for language and cognitive tasks are characteristics of many children with language difficulties. Individual differences in processing speed have not consistently been found to predict language ability or severity of language impairment. There are conflicting views on whether working memory and processing speed are integrated or separable abilities. To evaluate four models for the relations of individual differences in children's processing speed and working memory capacity in sentence imitation. The models considered whether working memory and processing speed are integrated or separable, as well as the effect of the number of operations required per sentence. The role of working memory as a mediator of the effect of processing speed on sentence imitation was also evaluated. Forty-six children with varied language and reading abilities imitated sentences. Working memory was measured with the Competing Language Processing Task (CLPT), and processing speed was measured with a composite of truth-value judgment and rapid automatized naming tasks. Mixed-effects ordinal regression models evaluated the CLPT and processing speed as predictors of sentence imitation item scores. A single mediator model evaluated working memory as a mediator of the effect of processing speed on sentence imitation total scores. Working memory was a reliable predictor of sentence imitation accuracy, but processing speed predicted sentence imitation only as a component of a processing speed by number of operations interaction. Processing speed predicted working memory capacity, and there was evidence that working memory acted as a mediator of the effect of processing speed on sentence imitation accuracy. The findings support a refined view of working memory and processing speed as separable factors in children's sentence imitation performance. Processing speed does not independently explain sentence imitation accuracy for all sentence types, but contributes when the task requires more mental operations. Processing speed also has an indirect effect on sentence imitation by contributing to working memory capacity. © 2013 Royal College of Speech and Language Therapists.

Q-marker based strategy for CMC research of Chinese medicine: A case study of Panax Notoginseng saponins.

PubMed

Zhong, Yi; Zhu, Jieqiang; Yang, Zhenzhong; Shao, Qing; Fan, Xiaohui; Cheng, Yiyu

2018-01-31

To ensure pharmaceutical quality, chemistry, manufacturing and control (CMC) research is essential. However, due to the inherent complexity of Chinese medicine (CM), CMC study of CM remains a great challenge for academia, industry, and regulatory agencies. Recently, quality-marker (Q-marker) was proposed to establish quality standards or quality analysis approaches of Chinese medicine, which sheds a light on Chinese medicine's CMC study. Here manufacture processes of Panax Notoginseng Saponins (PNS) is taken as a case study and the present work is to establish a Q-marker based research strategy for CMC of Chinese medicine. The Q-markers of Panax Notoginseng Saponins (PNS) is selected and established by integrating chemical profile with pharmacological activities. Then, the key processes of PNS manufacturing are identified by material flow analysis. Furthermore, modeling algorithms are employed to explore the relationship between Q-markers and critical process parameters (CPPs) of the key processes. At last, CPPs of the key processes are optimized in order to improving the process efficiency. Among the 97 identified compounds, Notoginsenoside R 1 , ginsenoside Rg 1 , Re, Rb 1 and Rd are selected as the Q-markers of PNS. Our analysis on PNS manufacturing show the extraction process and column chromatography process are the key processes. With the CPPs of each process as the inputs and Q-markers' contents as the outputs, two process prediction models are built separately for the extraction process and column chromatography process of Panax notoginseng, which both possess good prediction ability. Based on the efficiency models of extraction process and column chromatography process we constructed, the optimal CPPs of both processes are calculated. Our results show that the Q-markers derived from CMC research strategy can be applied to analyze the manufacturing processes of Chinese medicine to assure product's quality and promote key processes' efficiency simultaneously. Copyright © 2018 Elsevier GmbH. All rights reserved.

PyMS: a Python toolkit for processing of gas chromatography-mass spectrometry (GC-MS) data. Application and comparative study of selected tools

PubMed Central

2012-01-01

Background Gas chromatography–mass spectrometry (GC-MS) is a technique frequently used in targeted and non-targeted measurements of metabolites. Most existing software tools for processing of raw instrument GC-MS data tightly integrate data processing methods with graphical user interface facilitating interactive data processing. While interactive processing remains critically important in GC-MS applications, high-throughput studies increasingly dictate the need for command line tools, suitable for scripting of high-throughput, customized processing pipelines. Results PyMS comprises a library of functions for processing of instrument GC-MS data developed in Python. PyMS currently provides a complete set of GC-MS processing functions, including reading of standard data formats (ANDI- MS/NetCDF and JCAMP-DX), noise smoothing, baseline correction, peak detection, peak deconvolution, peak integration, and peak alignment by dynamic programming. A novel common ion single quantitation algorithm allows automated, accurate quantitation of GC-MS electron impact (EI) fragmentation spectra when a large number of experiments are being analyzed. PyMS implements parallel processing for by-row and by-column data processing tasks based on Message Passing Interface (MPI), allowing processing to scale on multiple CPUs in distributed computing environments. A set of specifically designed experiments was performed in-house and used to comparatively evaluate the performance of PyMS and three widely used software packages for GC-MS data processing (AMDIS, AnalyzerPro, and XCMS). Conclusions PyMS is a novel software package for the processing of raw GC-MS data, particularly suitable for scripting of customized processing pipelines and for data processing in batch mode. PyMS provides limited graphical capabilities and can be used both for routine data processing and interactive/exploratory data analysis. In real-life GC-MS data processing scenarios PyMS performs as well or better than leading software packages. We demonstrate data processing scenarios simple to implement in PyMS, yet difficult to achieve with many conventional GC-MS data processing software. Automated sample processing and quantitation with PyMS can provide substantial time savings compared to more traditional interactive software systems that tightly integrate data processing with the graphical user interface. PMID:22647087

The Research Process on Converter Steelmaking Process by Using Limestone

NASA Astrophysics Data System (ADS)

Tang, Biao; Li, Xing-yi; Cheng, Han-chi; Wang, Jing; Zhang, Yun-long

2017-08-01

Compared with traditional converter steelmaking process, steelmaking process with limestone uses limestone to replace lime partly. A lot of researchers have studied about the new steelmaking process. There are much related research about material balance calculation, the behaviour of limestone in the slag, limestone powder injection in converter and application of limestone in iron and steel enterprises. The results show that the surplus heat of converter can meet the need of the limestone calcination, and the new process can reduce the steelmaking process energy loss in the whole steelmaking process, reduce carbon dioxide emissions, and improve the quality of the gas.

Gas processing handbook

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1982-04-01

Brief details are given of processes including: BGC-Lurgi slagging gasification, COGAS, Exxon catalytic coal gasification, FW-Stoic 2-stage, GI two stage, HYGAS, Koppers-Totzek, Lurgi pressure gasification, Saarberg-Otto, Shell, Texaco, U-Gas, W-D.IGI, Wellman-Galusha, Westinghouse, and Winkler coal gasification processes; the Rectisol process; the Catacarb and the Benfield processes for removing CO/SUB/2, H/SUB/2s and COS from gases produced by the partial oxidation of coal; the selectamine DD, Selexol solvent, and Sulfinol gas cleaning processes; the sulphur-tolerant shift (SSK) process; and the Super-meth process for the production of high-Btu gas from synthesis gas.

Working on the Boundaries: Philosophies and Practices of the Design Process

NASA Technical Reports Server (NTRS)

Ryan, R.; Blair, J.; Townsend, J.; Verderaime, V.

1996-01-01

While systems engineering process is a program formal management technique and contractually binding, the design process is the informal practice of achieving the design project requirements throughout all design phases of the systems engineering process. The design process and organization are systems and component dependent. Informal reviews include technical information meetings and concurrent engineering sessions, and formal technical discipline reviews are conducted through the systems engineering process. This paper discusses and references major philosophical principles in the design process, identifies its role in interacting systems and disciplines analyses and integrations, and illustrates the process application in experienced aerostructural designs.

Chemical processing of lunar materials

NASA Technical Reports Server (NTRS)

Criswell, D. R.; Waldron, R. D.

1979-01-01

The paper highlights recent work on the general problem of processing lunar materials. The discussion covers lunar source materials, refined products, motivations for using lunar materials, and general considerations for a lunar or space processing plant. Attention is given to chemical processing through various techniques, including electrolysis of molten silicates, carbothermic/silicothermic reduction, carbo-chlorination process, NaOH basic-leach process, and HF acid-leach process. Several options for chemical processing of lunar materials are well within the state of the art of applied chemistry and chemical engineering to begin development based on the extensive knowledge of lunar materials.

Coordination and organization of security software process for power information application environment

NASA Astrophysics Data System (ADS)

Wang, Qiang

2017-09-01

As an important part of software engineering, the software process decides the success or failure of software product. The design and development feature of security software process is discussed, so is the necessity and the present significance of using such process. Coordinating the function software, the process for security software and its testing are deeply discussed. The process includes requirement analysis, design, coding, debug and testing, submission and maintenance. In each process, the paper proposed the subprocesses to support software security. As an example, the paper introduces the above process into the power information platform.

Sensor-based atomic layer deposition for rapid process learning and enhanced manufacturability

NASA Astrophysics Data System (ADS)

Lei, Wei

In the search for sensor based atomic layer deposition (ALD) process to accelerate process learning and enhance manufacturability, we have explored new reactor designs and applied in-situ process sensing to W and HfO 2 ALD processes. A novel wafer scale ALD reactor, which features fast gas switching, good process sensing compatibility and significant similarity to the real manufacturing environment, is constructed. The reactor has a unique movable reactor cap design that allows two possible operation modes: (1) steady-state flow with alternating gas species; or (2) fill-and-pump-out cycling of each gas, accelerating the pump-out by lifting the cap to employ the large chamber volume as ballast. Downstream quadrupole mass spectrometry (QMS) sampling is applied for in-situ process sensing of tungsten ALD process. The QMS reveals essential surface reaction dynamics through real-time signals associated with byproduct generation as well as precursor introduction and depletion for each ALD half cycle, which are then used for process learning and optimization. More subtle interactions such as imperfect surface saturation and reactant dose interaction are also directly observed by QMS, indicating that ALD process is more complicated than the suggested layer-by-layer growth. By integrating in real-time the byproduct QMS signals over each exposure and plotting it against process cycle number, the deposition kinetics on the wafer is directly measured. For continuous ALD runs, the total integrated byproduct QMS signal in each ALD run is also linear to ALD film thickness, and therefore can be used for ALD film thickness metrology. The in-situ process sensing is also applied to HfO2 ALD process that is carried out in a furnace type ALD reactor. Precursor dose end-point control is applied to precisely control the precursor dose in each half cycle. Multiple process sensors, including quartz crystal microbalance (QCM) and QMS are used to provide real time process information. The sensing results confirm the proposed surface reaction path and once again reveal the complexity of ALD processes. The impact of this work includes: (1) It explores new ALD reactor designs which enable the implementation of in-situ process sensors for rapid process learning and enhanced manufacturability; (2) It demonstrates in the first time that in-situ QMS can reveal detailed process dynamics and film growth kinetics in wafer-scale ALD process, and thus can be used for ALD film thickness metrology. (3) Based on results from two different processes carried out in two different reactors, it is clear that ALD is a more complicated process than normally believed or advertised, but real-time observation of the operational chemistries in ALD by in-situ sensors provides critical insight to the process and the basis for more effective process control for ALD applications.

Implicit Processes, Self-Regulation, and Interventions for Behavior Change.

PubMed

St Quinton, Tom; Brunton, Julie A

2017-01-01

The ability to regulate and subsequently change behavior is influenced by both reflective and implicit processes. Traditional theories have focused on conscious processes by highlighting the beliefs and intentions that influence decision making. However, their success in changing behavior has been modest with a gap between intention and behavior apparent. Dual-process models have been recently applied to health psychology; with numerous models incorporating implicit processes that influence behavior as well as the more common conscious processes. Such implicit processes are theorized to govern behavior non-consciously. The article provides a commentary on motivational and volitional processes and how interventions have combined to attempt an increase in positive health behaviors. Following this, non-conscious processes are discussed in terms of their theoretical underpinning. The article will then highlight how these processes have been measured and will then discuss the different ways that the non-conscious and conscious may interact. The development of interventions manipulating both processes may well prove crucial in successfully altering behavior.

All varieties of encoding variability are not created equal: Separating variable processing from variable tasks

PubMed Central

Huff, Mark J.; Bodner, Glen E.

2014-01-01

Whether encoding variability facilitates memory is shown to depend on whether item-specific and relational processing are both performed across study blocks, and whether study items are weakly versus strongly related. Variable-processing groups studied a word list once using an item-specific task and once using a relational task. Variable-task groups’ two different study tasks recruited the same type of processing each block. Repeated-task groups performed the same study task each block. Recall and recognition were greatest in the variable-processing group, but only with weakly related lists. A variable-processing benefit was also found when task-based processing and list-type processing were complementary (e.g., item-specific processing of a related list) rather than redundant (e.g., relational processing of a related list). That performing both item-specific and relational processing across trials, or within a trial, yields encoding-variability benefits may help reconcile decades of contradictory findings in this area. PMID:25018583

Continuous welding of unidirectional fiber reinforced thermoplastic tape material

NASA Astrophysics Data System (ADS)

Schledjewski, Ralf

2017-10-01

Continuous welding techniques like thermoplastic tape placement with in situ consolidation offer several advantages over traditional manufacturing processes like autoclave consolidation, thermoforming, etc. However, still there is a need to solve several important processing issues before it becomes a viable economic process. Intensive process analysis and optimization has been carried out in the past through experimental investigation, model definition and simulation development. Today process simulation is capable to predict resulting consolidation quality. Effects of material imperfections or process parameter variations are well known. But using this knowledge to control the process based on online process monitoring and according adaption of the process parameters is still challenging. Solving inverse problems and using methods for automated code generation allowing fast implementation of algorithms on targets are required. The paper explains the placement technique in general. Process-material-property-relationships and typical material imperfections are described. Furthermore, online monitoring techniques and how to use them for a model based process control system are presented.

Economics of polysilicon process: A view from Japan

NASA Technical Reports Server (NTRS)

Shimizu, Y.

1986-01-01

The production process of solar grade silicon (SOG-Si) through trichlorosilane (TCS) was researched in a program sponsored by New Energy Development Organization (NEDO). The NEDO process consists of the following two steps: TCS production from by-product silicon tetrachloride (STC) and SOG-Si formation from TCS using a fluidized bed reactor. Based on the data obtained during the research program, the manufacturing cost of the NEDO process and other polysilicon manufacturing processes were compared. The manufacturing cost was calculated on the basis of 1000 tons/year production. The cost estimate showed that the cost of producing silicon by all of the new processes is less than the cost by the conventional Siemens process. Using a new process, the cost of producing semiconductor grade silicon was found to be virtually the same with any to the TCS, diclorosilane, and monosilane processes when by-products were recycled. The SOG-Si manufacturing processes using the fluidized bed reactor, which needs further development, shows a greater probablility of cost reduction than the filament processes.

Autonomous Agents for Dynamic Process Planning in the Flexible Manufacturing System

NASA Astrophysics Data System (ADS)

Nik Nejad, Hossein Tehrani; Sugimura, Nobuhiro; Iwamura, Koji; Tanimizu, Yoshitaka

Rapid changes of market demands and pressures of competition require manufacturers to maintain highly flexible manufacturing systems to cope with a complex manufacturing environment. This paper deals with development of an agent-based architecture of dynamic systems for incremental process planning in the manufacturing systems. In consideration of alternative manufacturing processes and machine tools, the process plans and the schedules of the manufacturing resources are generated incrementally and dynamically. A negotiation protocol is discussed, in this paper, to generate suitable process plans for the target products real-timely and dynamically, based on the alternative manufacturing processes. The alternative manufacturing processes are presented by the process plan networks discussed in the previous paper, and the suitable process plans are searched and generated to cope with both the dynamic changes of the product specifications and the disturbances of the manufacturing resources. We initiatively combine the heuristic search algorithms of the process plan networks with the negotiation protocols, in order to generate suitable process plans in the dynamic manufacturing environment.

Implicit Processes, Self-Regulation, and Interventions for Behavior Change

PubMed Central

St Quinton, Tom; Brunton, Julie A.

2017-01-01

The ability to regulate and subsequently change behavior is influenced by both reflective and implicit processes. Traditional theories have focused on conscious processes by highlighting the beliefs and intentions that influence decision making. However, their success in changing behavior has been modest with a gap between intention and behavior apparent. Dual-process models have been recently applied to health psychology; with numerous models incorporating implicit processes that influence behavior as well as the more common conscious processes. Such implicit processes are theorized to govern behavior non-consciously. The article provides a commentary on motivational and volitional processes and how interventions have combined to attempt an increase in positive health behaviors. Following this, non-conscious processes are discussed in terms of their theoretical underpinning. The article will then highlight how these processes have been measured and will then discuss the different ways that the non-conscious and conscious may interact. The development of interventions manipulating both processes may well prove crucial in successfully altering behavior. PMID:28337164

Models of recognition: a review of arguments in favor of a dual-process account.

PubMed

Diana, Rachel A; Reder, Lynne M; Arndt, Jason; Park, Heekyeong

2006-02-01

The majority of computationally specified models of recognition memory have been based on a single-process interpretation, claiming that familiarity is the only influence on recognition. There is increasing evidence that recognition is, in fact, based on two processes: recollection and familiarity. This article reviews the current state of the evidence for dual-process models, including the usefulness of the remember/know paradigm, and interprets the relevant results in terms of the source of activation confusion (SAC) model of memory. We argue that the evidence from each of the areas we discuss, when combined, presents a strong case that inclusion of a recollection process is necessary. Given this conclusion, we also argue that the dual-process claim that the recollection process is always available is, in fact, more parsimonious than the single-process claim that the recollection process is used only in certain paradigms. The value of a well-specified process model such as the SAC model is discussed with regard to other types of dual-process models.

Integrating Thermal Tools Into the Mechanical Design Process

NASA Technical Reports Server (NTRS)

Tsuyuki, Glenn T.; Siebes, Georg; Novak, Keith S.; Kinsella, Gary M.

1999-01-01

The intent of mechanical design is to deliver a hardware product that meets or exceeds customer expectations, while reducing cycle time and cost. To this end, an integrated mechanical design process enables the idea of parallel development (concurrent engineering). This represents a shift from the traditional mechanical design process. With such a concurrent process, there are significant issues that have to be identified and addressed before re-engineering the mechanical design process to facilitate concurrent engineering. These issues also assist in the integration and re-engineering of the thermal design sub-process since it resides within the entire mechanical design process. With these issues in mind, a thermal design sub-process can be re-defined in a manner that has a higher probability of acceptance, thus enabling an integrated mechanical design process. However, the actual implementation is not always problem-free. Experience in applying the thermal design sub-process to actual situations provides the evidence for improvement, but more importantly, for judging the viability and feasibility of the sub-process.

[Monitoring method of extraction process for Schisandrae Chinensis Fructus based on near infrared spectroscopy and multivariate statistical process control].

PubMed

Xu, Min; Zhang, Lei; Yue, Hong-Shui; Pang, Hong-Wei; Ye, Zheng-Liang; Ding, Li

2017-10-01

To establish an on-line monitoring method for extraction process of Schisandrae Chinensis Fructus, the formula medicinal material of Yiqi Fumai lyophilized injection by combining near infrared spectroscopy with multi-variable data analysis technology. The multivariate statistical process control (MSPC) model was established based on 5 normal batches in production and 2 test batches were monitored by PC scores, DModX and Hotelling T2 control charts. The results showed that MSPC model had a good monitoring ability for the extraction process. The application of the MSPC model to actual production process could effectively achieve on-line monitoring for extraction process of Schisandrae Chinensis Fructus, and can reflect the change of material properties in the production process in real time. This established process monitoring method could provide reference for the application of process analysis technology in the process quality control of traditional Chinese medicine injections. Copyright© by the Chinese Pharmaceutical Association.

Method for automatically evaluating a transition from a batch manufacturing technique to a lean manufacturing technique

DOEpatents

Ivezic, Nenad; Potok, Thomas E.

2003-09-30

A method for automatically evaluating a manufacturing technique comprises the steps of: receiving from a user manufacturing process step parameters characterizing a manufacturing process; accepting from the user a selection for an analysis of a particular lean manufacturing technique; automatically compiling process step data for each process step in the manufacturing process; automatically calculating process metrics from a summation of the compiled process step data for each process step; and, presenting the automatically calculated process metrics to the user. A method for evaluating a transition from a batch manufacturing technique to a lean manufacturing technique can comprise the steps of: collecting manufacturing process step characterization parameters; selecting a lean manufacturing technique for analysis; communicating the selected lean manufacturing technique and the manufacturing process step characterization parameters to an automatic manufacturing technique evaluation engine having a mathematical model for generating manufacturing technique evaluation data; and, using the lean manufacturing technique evaluation data to determine whether to transition from an existing manufacturing technique to the selected lean manufacturing technique.

Process yield improvements with process control terminal for varian serial ion implanters

NASA Astrophysics Data System (ADS)

Higashi, Harry; Soni, Ameeta; Martinez, Larry; Week, Ken

Implant processes in a modern wafer production fab are extremely complex. There can be several types of misprocessing, i.e. wrong dose or species, double implants and missed implants. Process Control Terminals (PCT) for Varian 350Ds installed at Intel fabs were found to substantially reduce the number of misprocessing steps. This paper describes those misprocessing steps and their subsequent reduction with use of PCTs. Reliable and simple process control with serial process ion implanters has been in increasing demand. A well designed process control terminal greatly increases device yield by monitoring all pertinent implanter functions and enabling process engineering personnel to set up process recipes for simple and accurate system operation. By programming user-selectable interlocks, implant errors are reduced and those that occur are logged for further analysis and prevention. A process control terminal should also be compatible with office personal computers for greater flexibility in system use and data analysis. The impact from the capability of a process control terminal is increased productivity, ergo higher device yield.

An Aspect-Oriented Framework for Business Process Improvement

NASA Astrophysics Data System (ADS)

Pourshahid, Alireza; Mussbacher, Gunter; Amyot, Daniel; Weiss, Michael

Recently, many organizations invested in Business Process Management Systems (BPMSs) in order to automate and monitor their processes. Business Activity Monitoring is one of the essential modules of a BPMS as it provides the core monitoring capabilities. Although the natural step after process monitoring is process improvement, most of the existing systems do not provide the means to help users with the improvement step. In this paper, we address this issue by proposing an aspect-oriented framework that allows the impact of changes to business processes to be explored with what-if scenarios based on the most appropriate process redesign patterns among several possibilities. As the four cornerstones of a BPMS are process, goal, performance and validation views, these views need to be aligned automatically by any approach that intends to support automated improvement of business processes. Our framework therefore provides means to reflect process changes also in the other views of the business process. A health care case study presented as a proof of concept suggests that this novel approach is feasible.

Structure and Randomness of Continuous-Time, Discrete-Event Processes

NASA Astrophysics Data System (ADS)

Marzen, Sarah E.; Crutchfield, James P.

2017-10-01

Loosely speaking, the Shannon entropy rate is used to gauge a stochastic process' intrinsic randomness; the statistical complexity gives the cost of predicting the process. We calculate, for the first time, the entropy rate and statistical complexity of stochastic processes generated by finite unifilar hidden semi-Markov models—memoryful, state-dependent versions of renewal processes. Calculating these quantities requires introducing novel mathematical objects (ɛ -machines of hidden semi-Markov processes) and new information-theoretic methods to stochastic processes.

Combined mesophilic anaerobic and thermophilic aerobic digestion process for high-strength food wastewater to increase removal efficiency and reduce sludge discharge.

PubMed

Jang, H M; Park, S K; Ha, J H; Park, J M

2014-01-01

In this study, a process that combines the mesophilic anaerobic digestion (MAD) process with thermophilic aerobic digestion (TAD) for high-strength food wastewater (FWW) treatment was developed to examine the removal of organic matter and methane production. All effluent discharged from the MAD process was separated into solid and liquid portions. The liquid part was discarded and the sludge part was passed to the TAD process for further degradation. Then, the digested sludge from the TAD process was recycled back to the MAD unit to achieve low sludge discharge from the combined process. The reactor combination was operated in two phases: during Phase I, 40 d of total hydraulic retention time (HRT) was applied; during Phase II, 20 d was applied. HRT of the TAD process was fixed at 5 d. For a comparison, a control process (single-stage MAD) was operated with the same HRTs of the combined process. Our results indicated that the combined process showed over 90% total solids, volatile solids and chemical oxygen demand removal efficiencies. In addition, the combined process showed a significantly higher methane production rate than that of the control process. Consequently, the experimental data demonstrated that the combined MAD-TAD process was successfully employed for high-strength FWW treatment with highly efficient organic matter reduction and methane production.

Leading processes of patient care and treatment in hierarchical healthcare organizations in Sweden--process managers' experiences.

PubMed

Nilsson, Kerstin; Sandoff, Mette

2015-01-01

The purpose of this study is to gain better understanding of the roles and functions of process managers by describing Swedish process managers' experiences of leading processes involving patient care and treatment when working in a hierarchical health-care organization. This study is based on an explorative design. The data were gathered from interviews with 12 process managers at three Swedish hospitals. These data underwent qualitative and interpretative analysis with a modified editing style. The process managers' experiences of leading processes in a hierarchical health-care organization are described under three themes: having or not having a mandate, exposure to conflict situations and leading process development. The results indicate a need for clarity regarding process manager's responsibility and work content, which need to be communicated to all managers and staff involved in the patient care and treatment process, irrespective of department. There also needs to be an emphasis on realistic expectations and orientation of the goals that are an intrinsic part of the task of being a process manager. Generalizations from the results of the qualitative interview studies are limited, but a deeper understanding of the phenomenon was reached, which, in turn, can be transferred to similar settings. This study contributes qualitative descriptions of leading care and treatment processes in a functional, hierarchical health-care organization from process managers' experiences, a subject that has not been investigated earlier.

Information Technology Process Improvement Decision-Making: An Exploratory Study from the Perspective of Process Owners and Process Managers

ERIC Educational Resources Information Center

Lamp, Sandra A.

2012-01-01

There is information available in the literature that discusses information technology (IT) governance and investment decision making from an executive-level perception, yet there is little information available that offers the perspective of process owners and process managers pertaining to their role in IT process improvement and investment…

43 CFR 2884.17 - How will BLM process my Processing Category 6 application?

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false How will BLM process my Processing...-WAY UNDER THE MINERAL LEASING ACT Applying for MLA Grants or TUPs § 2884.17 How will BLM process my... written agreement that describes how BLM will process your application. The final agreement consists of a...

43 CFR 2884.17 - How will BLM process my Processing Category 6 application?

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false How will BLM process my Processing...-WAY UNDER THE MINERAL LEASING ACT Applying for MLA Grants or TUPs § 2884.17 How will BLM process my... written agreement that describes how BLM will process your application. The final agreement consists of a...

15 CFR 15.3 - Acceptance of service of process.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Acceptance of service of process. 15.3... Process § 15.3 Acceptance of service of process. (a) Except as otherwise provided in this subpart, any... employee by law is to be served personally with process. Service of process in this case is inadequate when...

Weaknesses in Applying a Process Approach in Industry Enterprises

NASA Astrophysics Data System (ADS)

Kučerová, Marta; Mĺkva, Miroslava; Fidlerová, Helena

2012-12-01

The paper deals with a process approach as one of the main principles of the quality management. Quality management systems based on process approach currently represents one of a proofed ways how to manage an organization. The volume of sales, costs and profit levels are influenced by quality of processes and efficient process flow. As results of the research project showed, there are some weaknesses in applying of the process approach in the industrial routine and it has been often only a formal change of the functional management to process management in many organizations in Slovakia. For efficient process management it is essential that companies take attention to the way how to organize their processes and seek for their continuous improvement.

Is Primary-Process Cognition a Feature of Hypnosis?

PubMed

Finn, Michael T; Goldman, Jared I; Lyon, Gyrid B; Nash, Michael R

2017-01-01

The division of cognition into primary and secondary processes is an important part of contemporary psychoanalytic metapsychology. Whereas primary processes are most characteristic of unconscious thought and loose associations, secondary processes generally govern conscious thought and logical reasoning. It has been theorized that an induction into hypnosis is accompanied by a predomination of primary-process cognition over secondary-process cognition. The authors hypothesized that highly hypnotizable individuals would demonstrate more primary-process cognition as measured by a recently developed cognitive-perceptual task. This hypothesis was not supported. In fact, low hypnotizable participants demonstrated higher levels of primary-process cognition. Exploratory analyses suggested a more specific effect: felt connectedness to the hypnotist seemed to promote secondary-process cognition among low hypnotizable participants.

[Dual process in large number estimation under uncertainty].

PubMed

Matsumuro, Miki; Miwa, Kazuhisa; Terai, Hitoshi; Yamada, Kento

2016-08-01

According to dual process theory, there are two systems in the mind: an intuitive and automatic System 1 and a logical and effortful System 2. While many previous studies about number estimation have focused on simple heuristics and automatic processes, the deliberative System 2 process has not been sufficiently studied. This study focused on the System 2 process for large number estimation. First, we described an estimation process based on participants’ verbal reports. The task, corresponding to the problem-solving process, consisted of creating subgoals, retrieving values, and applying operations. Second, we investigated the influence of such deliberative process by System 2 on intuitive estimation by System 1, using anchoring effects. The results of the experiment showed that the System 2 process could mitigate anchoring effects.

Object-processing neural efficiency differentiates object from spatial visualizers.

PubMed

Motes, Michael A; Malach, Rafael; Kozhevnikov, Maria

2008-11-19

The visual system processes object properties and spatial properties in distinct subsystems, and we hypothesized that this distinction might extend to individual differences in visual processing. We conducted a functional MRI study investigating the neural underpinnings of individual differences in object versus spatial visual processing. Nine participants of high object-processing ability ('object' visualizers) and eight participants of high spatial-processing ability ('spatial' visualizers) were scanned, while they performed an object-processing task. Object visualizers showed lower bilateral neural activity in lateral occipital complex and lower right-lateralized neural activity in dorsolateral prefrontal cortex. The data indicate that high object-processing ability is associated with more efficient use of visual-object resources, resulting in less neural activity in the object-processing pathway.

Process simulation for advanced composites production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allendorf, M.D.; Ferko, S.M.; Griffiths, S.

1997-04-01

The objective of this project is to improve the efficiency and lower the cost of chemical vapor deposition (CVD) processes used to manufacture advanced ceramics by providing the physical and chemical understanding necessary to optimize and control these processes. Project deliverables include: numerical process models; databases of thermodynamic and kinetic information related to the deposition process; and process sensors and software algorithms that can be used for process control. Target manufacturing techniques include CVD fiber coating technologies (used to deposit interfacial coatings on continuous fiber ceramic preforms), chemical vapor infiltration, thin-film deposition processes used in the glass industry, and coatingmore » techniques used to deposit wear-, abrasion-, and corrosion-resistant coatings for use in the pulp and paper, metals processing, and aluminum industries.« less

CDO budgeting

NASA Astrophysics Data System (ADS)

Nesladek, Pavel; Wiswesser, Andreas; Sass, Björn; Mauermann, Sebastian

2008-04-01

The Critical dimension off-target (CDO) is a key parameter for mask house customer, affecting directly the performance of the mask. The CDO is the difference between the feature size target and the measured feature size. The change of CD during the process is either compensated within the process or by data correction. These compensation methods are commonly called process bias and data bias, respectively. The difference between data bias and process bias in manufacturing results in systematic CDO error, however, this systematic error does not take into account the instability of the process bias. This instability is a result of minor variations - instabilities of manufacturing processes and changes in materials and/or logistics. Using several masks the CDO of the manufacturing line can be estimated. For systematic investigation of the unit process contribution to CDO and analysis of the factors influencing the CDO contributors, a solid understanding of each unit process and huge number of masks is necessary. Rough identification of contributing processes and splitting of the final CDO variation between processes can be done with approx. 50 masks with identical design, material and process. Such amount of data allows us to identify the main contributors and estimate the effect of them by means of Analysis of variance (ANOVA) combined with multivariate analysis. The analysis does not provide information about the root cause of the variation within the particular unit process, however, it provides a good estimate of the impact of the process on the stability of the manufacturing line. Additionally this analysis can be used to identify possible interaction between processes, which cannot be investigated if only single processes are considered. Goal of this work is to evaluate limits for CDO budgeting models given by the precision and the number of measurements as well as partitioning the variation within the manufacturing process. The CDO variation splits according to the suggested model into contributions from particular processes or process groups. Last but not least the power of this method to determine the absolute strength of each parameter will be demonstrated. Identification of the root cause of this variation within the unit process itself is not scope of this work.

Application of high-throughput mini-bioreactor system for systematic scale-down modeling, process characterization, and control strategy development.

PubMed

Janakiraman, Vijay; Kwiatkowski, Chris; Kshirsagar, Rashmi; Ryll, Thomas; Huang, Yao-Ming

2015-01-01

High-throughput systems and processes have typically been targeted for process development and optimization in the bioprocessing industry. For process characterization, bench scale bioreactors have been the system of choice. Due to the need for performing different process conditions for multiple process parameters, the process characterization studies typically span several months and are considered time and resource intensive. In this study, we have shown the application of a high-throughput mini-bioreactor system viz. the Advanced Microscale Bioreactor (ambr15(TM) ), to perform process characterization in less than a month and develop an input control strategy. As a pre-requisite to process characterization, a scale-down model was first developed in the ambr system (15 mL) using statistical multivariate analysis techniques that showed comparability with both manufacturing scale (15,000 L) and bench scale (5 L). Volumetric sparge rates were matched between ambr and manufacturing scale, and the ambr process matched the pCO2 profiles as well as several other process and product quality parameters. The scale-down model was used to perform the process characterization DoE study and product quality results were generated. Upon comparison with DoE data from the bench scale bioreactors, similar effects of process parameters on process yield and product quality were identified between the two systems. We used the ambr data for setting action limits for the critical controlled parameters (CCPs), which were comparable to those from bench scale bioreactor data. In other words, the current work shows that the ambr15(TM) system is capable of replacing the bench scale bioreactor system for routine process development and process characterization. © 2015 American Institute of Chemical Engineers.

Consumers' conceptualization of ultra-processed foods.

PubMed

Ares, Gastón; Vidal, Leticia; Allegue, Gimena; Giménez, Ana; Bandeira, Elisa; Moratorio, Ximena; Molina, Verónika; Curutchet, María Rosa

2016-10-01

Consumption of ultra-processed foods has been associated with low diet quality, obesity and other non-communicable diseases. This situation makes it necessary to develop educational campaigns to discourage consumers from substituting meals based on unprocessed or minimally processed foods by ultra-processed foods. In this context, the aim of the present work was to investigate how consumers conceptualize the term ultra-processed foods and to evaluate if the foods they perceive as ultra-processed are in concordance with the products included in the NOVA classification system. An online study was carried out with 2381 participants. They were asked to explain what they understood by ultra-processed foods and to list foods that can be considered ultra-processed. Responses were analysed using inductive coding. The great majority of the participants was able to provide an explanation of what ultra-processed foods are, which was similar to the definition described in the literature. Most of the participants described ultra-processed foods as highly processed products that usually contain additives and other artificial ingredients, stressing that they have low nutritional quality and are unhealthful. The most relevant products for consumers' conceptualization of the term were in agreement with the NOVA classification system and included processed meats, soft drinks, snacks, burgers, powdered and packaged soups and noodles. However, some of the participants perceived processed foods, culinary ingredients and even some minimally processed foods as ultra-processed. This suggests that in order to accurately convey their message, educational campaigns aimed at discouraging consumers from consuming ultra-processed foods should include a clear definition of the term and describe some of their specific characteristics, such as the type of ingredients included in their formulation and their nutritional composition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rapid communication: Global-local processing affects recognition of distractor emotional faces.

PubMed

Srinivasan, Narayanan; Gupta, Rashmi

2011-03-01

Recent studies have shown links between happy faces and global, distributed attention as well as sad faces to local, focused attention. Emotions have been shown to affect global-local processing. Given that studies on emotion-cognition interactions have not explored the effect of perceptual processing at different spatial scales on processing stimuli with emotional content, the present study investigated the link between perceptual focus and emotional processing. The study investigated the effects of global-local processing on the recognition of distractor faces with emotional expressions. Participants performed a digit discrimination task with digits at either the global level or the local level presented against a distractor face (happy or sad) as background. The results showed that global processing associated with broad scope of attention facilitates recognition of happy faces, and local processing associated with narrow scope of attention facilitates recognition of sad faces. The novel results of the study provide conclusive evidence for emotion-cognition interactions by demonstrating the effect of perceptual processing on emotional faces. The results along with earlier complementary results on the effect of emotion on global-local processing support a reciprocal relationship between emotional processing and global-local processing. Distractor processing with emotional information also has implications for theories of selective attention.

Tomographical process monitoring of laser transmission welding with OCT

NASA Astrophysics Data System (ADS)

Ackermann, Philippe; Schmitt, Robert

2017-06-01

Process control of laser processes still encounters many obstacles. Although these processes are stable, a narrow process parameter window during the process or process deviations have led to an increase on the requirements for the process itself and on monitoring devices. Laser transmission welding as a contactless and locally limited joining technique is well-established in a variety of demanding production areas. For example, sensitive parts demand a particle-free joining technique which does not affect the inner components. Inline integrated non-destructive optical measurement systems capable of providing non-invasive tomographical images of the transparent material, the weld seam and its surrounding areas with micron resolution would improve the overall process. Obtained measurement data enable qualitative feedback into the system to adapt parameters for a more robust process. Within this paper we present the inline monitoring device based on Fourier-domain optical coherence tomography developed within the European-funded research project "Manunet Weldable". This device, after adaptation to the laser transmission welding process is optically and mechanically integrated into the existing laser system. The main target lies within the inline process control destined to extract tomographical geometrical measurement data from the weld seam forming process. Usage of this technology makes offline destructive testing of produced parts obsolete. 1,2,3,4

A quality-refinement process for medical imaging applications.

PubMed

Neuhaus, J; Maleike, D; Nolden, M; Kenngott, H-G; Meinzer, H-P; Wolf, I

2009-01-01

To introduce and evaluate a process for refinement of software quality that is suitable to research groups. In order to avoid constraining researchers too much, the quality improvement process has to be designed carefully. The scope of this paper is to present and evaluate a process to advance quality aspects of existing research prototypes in order to make them ready for initial clinical studies. The proposed process is tailored for research environments and therefore more lightweight than traditional quality management processes. Focus on quality criteria that are important at the given stage of the software life cycle. Usage of tools that automate aspects of the process is emphasized. To evaluate the additional effort that comes along with the process, it was exemplarily applied for eight prototypical software modules for medical image processing. The introduced process has been applied to improve the quality of all prototypes so that they could be successfully used in clinical studies. The quality refinement yielded an average of 13 person days of additional effort per project. Overall, 107 bugs were found and resolved by applying the process. Careful selection of quality criteria and the usage of automated process tools lead to a lightweight quality refinement process suitable for scientific research groups that can be applied to ensure a successful transfer of technical software prototypes into clinical research workflows.

Negative Binomial Process Count and Mixture Modeling.

PubMed

Zhou, Mingyuan; Carin, Lawrence

2015-02-01

The seemingly disjoint problems of count and mixture modeling are united under the negative binomial (NB) process. A gamma process is employed to model the rate measure of a Poisson process, whose normalization provides a random probability measure for mixture modeling and whose marginalization leads to an NB process for count modeling. A draw from the NB process consists of a Poisson distributed finite number of distinct atoms, each of which is associated with a logarithmic distributed number of data samples. We reveal relationships between various count- and mixture-modeling distributions and construct a Poisson-logarithmic bivariate distribution that connects the NB and Chinese restaurant table distributions. Fundamental properties of the models are developed, and we derive efficient Bayesian inference. It is shown that with augmentation and normalization, the NB process and gamma-NB process can be reduced to the Dirichlet process and hierarchical Dirichlet process, respectively. These relationships highlight theoretical, structural, and computational advantages of the NB process. A variety of NB processes, including the beta-geometric, beta-NB, marked-beta-NB, marked-gamma-NB and zero-inflated-NB processes, with distinct sharing mechanisms, are also constructed. These models are applied to topic modeling, with connections made to existing algorithms under Poisson factor analysis. Example results show the importance of inferring both the NB dispersion and probability parameters.

[Process management in the hospital pharmacy for the improvement of the patient safety].

PubMed

Govindarajan, R; Perelló-Juncá, A; Parès-Marimòn, R M; Serrais-Benavente, J; Ferrandez-Martí, D; Sala-Robinat, R; Camacho-Calvente, A; Campabanal-Prats, C; Solà-Anderiu, I; Sanchez-Caparrós, S; Gonzalez-Estrada, J; Martinez-Olalla, P; Colomer-Palomo, J; Perez-Mañosas, R; Rodríguez-Gallego, D

2013-01-01

To define a process management model for a hospital pharmacy in order to measure, analyse and make continuous improvements in patient safety and healthcare quality. In order to implement process management, Igualada Hospital was divided into different processes, one of which was the Hospital Pharmacy. A multidisciplinary management team was given responsibility for each process. For each sub-process one person was identified to be responsible, and a working group was formed under his/her leadership. With the help of each working group, a risk analysis using failure modes and effects analysis (FMEA) was performed, and the corresponding improvement actions were implemented. Sub-process indicators were also identified, and different process management mechanisms were introduced. The first risk analysis with FMEA produced more than thirty preventive actions to improve patient safety. Later, the weekly analysis of errors, as well as the monthly analysis of key process indicators, permitted us to monitor process results and, as each sub-process manager participated in these meetings, also to assume accountability and responsibility, thus consolidating the culture of excellence. The introduction of different process management mechanisms, with the participation of people responsible for each sub-process, introduces a participative management tool for the continuous improvement of patient safety and healthcare quality. Copyright © 2012 SECA. Published by Elsevier Espana. All rights reserved.

Distributed processing method for arbitrary view generation in camera sensor network

NASA Astrophysics Data System (ADS)

Tehrani, Mehrdad P.; Fujii, Toshiaki; Tanimoto, Masayuki

2003-05-01

Camera sensor network as a new advent of technology is a network that each sensor node can capture video signals, process and communicate them with other nodes. The processing task in this network is to generate arbitrary view, which can be requested from central node or user. To avoid unnecessary communication between nodes in camera sensor network and speed up the processing time, we have distributed the processing tasks between nodes. In this method, each sensor node processes part of interpolation algorithm to generate the interpolated image with local communication between nodes. The processing task in camera sensor network is ray-space interpolation, which is an object independent method and based on MSE minimization by using adaptive filtering. Two methods were proposed for distributing processing tasks, which are Fully Image Shared Decentralized Processing (FIS-DP), and Partially Image Shared Decentralized Processing (PIS-DP), to share image data locally. Comparison of the proposed methods with Centralized Processing (CP) method shows that PIS-DP has the highest processing speed after FIS-DP, and CP has the lowest processing speed. Communication rate of CP and PIS-DP is almost same and better than FIS-DP. So, PIS-DP is recommended because of its better performance than CP and FIS-DP.

EEG alpha synchronization is related to top-down processing in convergent and divergent thinking

PubMed Central

Benedek, Mathias; Bergner, Sabine; Könen, Tanja; Fink, Andreas; Neubauer, Aljoscha C.

2011-01-01

Synchronization of EEG alpha activity has been referred to as being indicative of cortical idling, but according to more recent evidence it has also been associated with active internal processing and creative thinking. The main objective of this study was to investigate to what extent EEG alpha synchronization is related to internal processing demands and to specific cognitive process involved in creative thinking. To this end, EEG was measured during a convergent and a divergent thinking task (i.e., creativity-related task) which once were processed involving low and once involving high internal processing demands. High internal processing demands were established by masking the stimulus (after encoding) and thus preventing further bottom-up processing. Frontal alpha synchronization was observed during convergent and divergent thinking only under exclusive top-down control (high internal processing demands), but not when bottom-up processing was allowed (low internal processing demands). We conclude that frontal alpha synchronization is related to top-down control rather than to specific creativity-related cognitive processes. Frontal alpha synchronization, which has been observed in a variety of different creativity tasks, thus may not reflect a brain state that is specific for creative cognition but can probably be attributed to high internal processing demands which are typically involved in creative thinking. PMID:21925520

Kennedy Space Center Payload Processing

NASA Technical Reports Server (NTRS)

Lawson, Ronnie; Engler, Tom; Colloredo, Scott; Zide, Alan

2011-01-01

This slide presentation reviews the payload processing functions at Kennedy Space Center. It details some of the payloads processed at KSC, the typical processing tasks, the facilities available for processing payloads, and the capabilities and customer services that are available.

Improving the Document Development Process: Integrating Relational Data and Statistical Process Control.

ERIC Educational Resources Information Center

Miller, John

1994-01-01

Presents an approach to document numbering, document titling, and process measurement which, when used with fundamental techniques of statistical process control, reveals meaningful process-element variation as well as nominal productivity models. (SR)

USE OF INDICATOR ORGANISMS FOR DETERMINING PROCESS EFFECTIVENESS

EPA Science Inventory

Wastewaters, process effluents and treatment process residuals contain a variety of microorganisms. Many factors influence their densities as they move through collection systems and process equipment. Biological treatment systems rely on the catabolic processes of such microor...

Food processing by high hydrostatic pressure.

PubMed

Yamamoto, Kazutaka

2017-04-01

High hydrostatic pressure (HHP) process, as a nonthermal process, can be used to inactivate microbes while minimizing chemical reactions in food. In this regard, a HHP level of 100 MPa (986.9 atm/1019.7 kgf/cm 2 ) and more is applied to food. Conventional thermal process damages food components relating color, flavor, and nutrition via enhanced chemical reactions. However, HHP process minimizes the damages and inactivates microbes toward processing high quality safe foods. The first commercial HHP-processed foods were launched in 1990 as fruit products such as jams, and then some other products have been commercialized: retort rice products (enhanced water impregnation), cooked hams and sausages (shelf life extension), soy sauce with minimized salt (short-time fermentation owing to enhanced enzymatic reactions), and beverages (shelf life extension). The characteristics of HHP food processing are reviewed from viewpoints of nonthermal process, history, research and development, physical and biochemical changes, and processing equipment.

[Near infrared spectroscopy based process trajectory technology and its application in monitoring and controlling of traditional Chinese medicine manufacturing process].

PubMed

Li, Wen-Long; Qu, Hai-Bin

2016-10-01

In this paper, the principle of NIRS (near infrared spectroscopy)-based process trajectory technology was introduced.The main steps of the technique include:① in-line collection of the processes spectra of different technics; ② unfolding of the 3-D process spectra;③ determination of the process trajectories and their normal limits;④ monitoring of the new batches with the established MSPC (multivariate statistical process control) models.Applications of the technology in the chemical and biological medicines were reviewed briefly. By a comprehensive introduction of our feasibility research on the monitoring of traditional Chinese medicine technical process using NIRS-based multivariate process trajectories, several important problems of the practical applications which need urgent solutions are proposed, and also the application prospect of the NIRS-based process trajectory technology is fully discussed and put forward in the end. Copyright© by the Chinese Pharmaceutical Association.

Recollection is a continuous process: implications for dual-process theories of recognition memory.

PubMed

Mickes, Laura; Wais, Peter E; Wixted, John T

2009-04-01

Dual-process theory, which holds that recognition decisions can be based on recollection or familiarity, has long seemed incompatible with signal detection theory, which holds that recognition decisions are based on a singular, continuous memory-strength variable. Formal dual-process models typically regard familiarity as a continuous process (i.e., familiarity comes in degrees), but they construe recollection as a categorical process (i.e., recollection either occurs or does not occur). A continuous process is characterized by a graded relationship between confidence and accuracy, whereas a categorical process is characterized by a binary relationship such that high confidence is associated with high accuracy but all lower degrees of confidence are associated with chance accuracy. Using a source-memory procedure, we found that the relationship between confidence and source-recollection accuracy was graded. Because recollection, like familiarity, is a continuous process, dual-process theory is more compatible with signal detection theory than previously thought.

A qualitative assessment of a random process proposed as an atmospheric turbulence model

NASA Technical Reports Server (NTRS)

Sidwell, K.

1977-01-01

A random process is formed by the product of two Gaussian processes and the sum of that product with a third Gaussian process. The resulting total random process is interpreted as the sum of an amplitude modulated process and a slowly varying, random mean value. The properties of the process are examined, including an interpretation of the process in terms of the physical structure of atmospheric motions. The inclusion of the mean value variation gives an improved representation of the properties of atmospheric motions, since the resulting process can account for the differences in the statistical properties of atmospheric velocity components and their gradients. The application of the process to atmospheric turbulence problems, including the response of aircraft dynamic systems, is examined. The effects of the mean value variation upon aircraft loads are small in most cases, but can be important in the measurement and interpretation of atmospheric turbulence data.

Metals Recovery from Artificial Ore in Case of Printed Circuit Boards, Using Plasmatron Plasma Reactor

PubMed Central

Szałatkiewicz, Jakub

2016-01-01

This paper presents the investigation of metals production form artificial ore, which consists of printed circuit board (PCB) waste, processed in plasmatron plasma reactor. A test setup was designed and built that enabled research of plasma processing of PCB waste of more than 700 kg/day scale. The designed plasma process is presented and discussed. The process in tests consumed 2 kWh/kg of processed waste. Investigation of the process products is presented with their elemental analyses of metals and slag. The average recovery of metals in presented experiments is 76%. Metals recovered include: Ag, Au, Pd, Cu, Sn, Pb, and others. The chosen process parameters are presented: energy consumption, throughput, process temperatures, and air consumption. Presented technology allows processing of variable and hard-to-process printed circuit board waste that can reach up to 100% of the input mass. PMID:28773804

Characterisation and Processing of Some Iron Ores of India

NASA Astrophysics Data System (ADS)

Krishna, S. J. G.; Patil, M. R.; Rudrappa, C.; Kumar, S. P.; Ravi, B. P.

2013-10-01

Lack of process characterization data of the ores based on the granulometry, texture, mineralogy, physical, chemical, properties, merits and limitations of process, market and local conditions may mislead the mineral processing entrepreneur. The proper implementation of process characterization and geotechnical map data will result in optimized sustainable utilization of resource by processing. A few case studies of process characterization of some Indian iron ores are dealt with. The tentative ascending order of process refractoriness of iron ores is massive hematite/magnetite < marine black iron oxide sands < laminated soft friable siliceous ore fines < massive banded magnetite quartzite < laminated soft friable clayey aluminous ore fines < massive banded hematite quartzite/jasper < massive clayey hydrated iron oxide ore < manganese bearing iron ores massive < Ti-V bearing magnetite magmatic ore < ferruginous cherty quartzite. Based on diagnostic process characterization, the ores have been classified and generic process have been adopted for some Indian iron ores.

Measuring health care process quality with software quality measures.

PubMed

Yildiz, Ozkan; Demirörs, Onur

2012-01-01

Existing quality models focus on some specific diseases, clinics or clinical areas. Although they contain structure, process, or output type measures, there is no model which measures quality of health care processes comprehensively. In addition, due to the not measured overall process quality, hospitals cannot compare quality of processes internally and externally. To bring a solution to above problems, a new model is developed from software quality measures. We have adopted the ISO/IEC 9126 software quality standard for health care processes. Then, JCIAS (Joint Commission International Accreditation Standards for Hospitals) measurable elements were added to model scope for unifying functional requirements. Assessment (diagnosing) process measurement results are provided in this paper. After the application, it was concluded that the model determines weak and strong aspects of the processes, gives a more detailed picture for the process quality, and provides quantifiable information to hospitals to compare their processes with multiple organizations.

Thermal Stir Welding: A New Solid State Welding Process

NASA Technical Reports Server (NTRS)

Ding, R. Jeffrey

2003-01-01

Thermal stir welding is a new welding process developed at NASA's Marshall Space Flight Center in Huntsville, AL. Thermal stir welding is similar to friction stir welding in that it joins similar or dissimilar materials without melting the parent material. However, unlike friction stir welding, the heating, stirring and forging elements of the process are all independent of each other and are separately controlled. Furthermore, the heating element of the process can be either a solid-state process (such as a thermal blanket, induction type process, etc), or, a fusion process (YG laser, plasma torch, etc.) The separation of the heating, stirring, forging elements of the process allows more degrees of freedom for greater process control. This paper introduces the mechanics of the thermal stir welding process. In addition, weld mechanical property data is presented for selected alloys as well as metallurgical analysis.

Thermal Stir Welding: A New Solid State Welding Process

NASA Technical Reports Server (NTRS)

Ding, R. Jeffrey; Munafo, Paul M. (Technical Monitor)

2002-01-01

Thermal stir welding is a new welding process developed at NASA's Marshall Space Flight Center in Huntsville, AL. Thermal stir welding is similar to friction stir welding in that it joins similar or dissimilar materials without melting the parent material. However, unlike friction stir welding, the heating, stirring and forging elements of the process are all independent of each other and are separately controlled. Furthermore, the heating element of the process can be either a solid-state process (such as a thermal blanket, induction type process, etc), or, a fusion process (YG laser, plasma torch, etc.) The separation of the heating, stirring, forging elements of the process allows more degrees of freedom for greater process control. This paper introduces the mechanics of the thermal stir welding process. In addition, weld mechanical property data is presented for selected alloys as well as metallurgical analysis.

Metals Recovery from Artificial Ore in Case of Printed Circuit Boards, Using Plasmatron Plasma Reactor.

PubMed

Szałatkiewicz, Jakub

2016-08-10

This paper presents the investigation of metals production form artificial ore, which consists of printed circuit board (PCB) waste, processed in plasmatron plasma reactor. A test setup was designed and built that enabled research of plasma processing of PCB waste of more than 700 kg/day scale. The designed plasma process is presented and discussed. The process in tests consumed 2 kWh/kg of processed waste. Investigation of the process products is presented with their elemental analyses of metals and slag. The average recovery of metals in presented experiments is 76%. Metals recovered include: Ag, Au, Pd, Cu, Sn, Pb, and others. The chosen process parameters are presented: energy consumption, throughput, process temperatures, and air consumption. Presented technology allows processing of variable and hard-to-process printed circuit board waste that can reach up to 100% of the input mass.

The origins of levels-of-processing effects in a conceptual test: evidence for automatic influences of memory from the process-dissociation procedure.

PubMed

Bergerbest, Dafna; Goshen-Gottstein, Yonatan

2002-12-01

In three experiments, we explored automatic influences of memory in a conceptual memory task, as affected by a levels-of-processing (LoP) manipulation. We also explored the origins of the LoP effect by examining whether the effect emerged only when participants in the shallow condition truncated the perceptual processing (the lexical-processing hypothesis) or even when the entire word was encoded in this condition (the conceptual-processing hypothesis). Using the process-dissociation procedure and an implicit association-generation task, we found that the deep encoding condition yielded higher estimates of automatic influences than the shallow condition. In support of the conceptual processing hypothesis, the LoP effect was found even when the shallow task did not lead to truncated processing of the lexical units. We suggest that encoding for meaning is a prerequisite for automatic processing on conceptual tests of memory.

Exploring business process modelling paradigms and design-time to run-time transitions

NASA Astrophysics Data System (ADS)

Caron, Filip; Vanthienen, Jan

2016-09-01

The business process management literature describes a multitude of approaches (e.g. imperative, declarative or event-driven) that each result in a different mix of process flexibility, compliance, effectiveness and efficiency. Although the use of a single approach over the process lifecycle is often assumed, transitions between approaches at different phases in the process lifecycle may also be considered. This article explores several business process strategies by analysing the approaches at different phases in the process lifecycle as well as the various transitions.

System Engineering Concept Demonstration, Process Model. Volume 3

DTIC Science & Technology

1992-12-01

Process or Process Model The System Engineering process must be the enactment of the aforementioned definitions. Therefore, a process is an enactment of a...Prototype Tradeoff Scenario demonstrates six levels of abstraction in the Process Model. The Process Model symbology is explained within the "Help" icon ...dnofing no- ubeq t"vidi e /hn -am-a. lmi IzyuO ..pu Row _e._n au"c.ue-w’ ’- anuiildyidwile b ie htplup ?~imsav D symbo ,,ue,.dvu ,,dienl Flw s--..,fu..I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eun, H.C.; Cho, Y.Z.; Choi, J.H.

A regeneration process of LiCl-KCl eutectic waste salt generated from the pyrochemical process of spent nuclear fuel has been studied. This regeneration process is composed of a chemical conversion process and a vacuum distillation process. Through the regeneration process, a high efficiency of renewable salt recovery can be obtained from the waste salt and rare earth nuclides in the waste salt can be separated as oxide or phosphate forms. Thus, the regeneration process can contribute greatly to a reduction of the waste volume and a creation of durable final waste forms. (authors)

An open system approach to process reengineering in a healthcare operational environment.

PubMed

Czuchry, A J; Yasin, M M; Norris, J

2000-01-01

The objective of this study is to examine the applicability of process reengineering in a healthcare operational environment. The intake process of a mental healthcare service delivery system is analyzed systematically to identify process-related problems. A methodology which utilizes an open system orientation coupled with process reengineering is utilized to overcome operational and patient related problems associated with the pre-reengineered intake process. The systematic redesign of the intake process resulted in performance improvements in terms of cost, quality, service and timing.

Developing the JPL Engineering Processes

NASA Technical Reports Server (NTRS)

Linick, Dave; Briggs, Clark

2004-01-01

This paper briefly recounts the recent history of process reengineering at the NASA Jet Propulsion Laboratory, with a focus on the engineering processes. The JPL process structure is described and the process development activities of the past several years outlined. The main focus of the paper is on the current process structure, the emphasis on the flight project life cycle, the governance approach that lead to Flight Project Practices, and the remaining effort to capture process knowledge at the detail level of the work group.

Water-saving liquid-gas conditioning system

DOEpatents

Martin, Christopher; Zhuang, Ye

2014-01-14

A method for treating a process gas with a liquid comprises contacting a process gas with a hygroscopic working fluid in order to remove a constituent from the process gas. A system for treating a process gas with a liquid comprises a hygroscopic working fluid comprising a component adapted to absorb or react with a constituent of a process gas, and a liquid-gas contactor for contacting the working fluid and the process gas, wherein the constituent is removed from the process gas within the liquid-gas contactor.

Model for Simulating a Spiral Software-Development Process

NASA Technical Reports Server (NTRS)

Mizell, Carolyn; Curley, Charles; Nayak, Umanath

2010-01-01

A discrete-event simulation model, and a computer program that implements the model, have been developed as means of analyzing a spiral software-development process. This model can be tailored to specific development environments for use by software project managers in making quantitative cases for deciding among different software-development processes, courses of action, and cost estimates. A spiral process can be contrasted with a waterfall process, which is a traditional process that consists of a sequence of activities that include analysis of requirements, design, coding, testing, and support. A spiral process is an iterative process that can be regarded as a repeating modified waterfall process. Each iteration includes assessment of risk, analysis of requirements, design, coding, testing, delivery, and evaluation. A key difference between a spiral and a waterfall process is that a spiral process can accommodate changes in requirements at each iteration, whereas in a waterfall process, requirements are considered to be fixed from the beginning and, therefore, a waterfall process is not flexible enough for some projects, especially those in which requirements are not known at the beginning or may change during development. For a given project, a spiral process may cost more and take more time than does a waterfall process, but may better satisfy a customer's expectations and needs. Models for simulating various waterfall processes have been developed previously, but until now, there have been no models for simulating spiral processes. The present spiral-process-simulating model and the software that implements it were developed by extending a discrete-event simulation process model of the IEEE 12207 Software Development Process, which was built using commercially available software known as the Process Analysis Tradeoff Tool (PATT). Typical inputs to PATT models include industry-average values of product size (expressed as number of lines of code), productivity (number of lines of code per hour), and number of defects per source line of code. The user provides the number of resources, the overall percent of effort that should be allocated to each process step, and the number of desired staff members for each step. The output of PATT includes the size of the product, a measure of effort, a measure of rework effort, the duration of the entire process, and the numbers of injected, detected, and corrected defects as well as a number of other interesting features. In the development of the present model, steps were added to the IEEE 12207 waterfall process, and this model and its implementing software were made to run repeatedly through the sequence of steps, each repetition representing an iteration in a spiral process. Because the IEEE 12207 model is founded on a waterfall paradigm, it enables direct comparison of spiral and waterfall processes. The model can be used throughout a software-development project to analyze the project as more information becomes available. For instance, data from early iterations can be used as inputs to the model, and the model can be used to estimate the time and cost of carrying the project to completion.

Magnitude processing of symbolic and non-symbolic proportions: an fMRI study.

PubMed

Mock, Julia; Huber, Stefan; Bloechle, Johannes; Dietrich, Julia F; Bahnmueller, Julia; Rennig, Johannes; Klein, Elise; Moeller, Korbinian

2018-05-10

Recent research indicates that processing proportion magnitude is associated with activation in the intraparietal sulcus. Thus, brain areas associated with the processing of numbers (i.e., absolute magnitude) were activated during processing symbolic fractions as well as non-symbolic proportions. Here, we investigated systematically the cognitive processing of symbolic (e.g., fractions and decimals) and non-symbolic proportions (e.g., dot patterns and pie charts) in a two-stage procedure. First, we investigated relative magnitude-related activations of proportion processing. Second, we evaluated whether symbolic and non-symbolic proportions share common neural substrates. We conducted an fMRI study using magnitude comparison tasks with symbolic and non-symbolic proportions, respectively. As an indicator for magnitude-related processing of proportions, the distance effect was evaluated. A conjunction analysis indicated joint activation of specific occipito-parietal areas including right intraparietal sulcus (IPS) during proportion magnitude processing. More specifically, results indicate that the IPS, which is commonly associated with absolute magnitude processing, is involved in processing relative magnitude information as well, irrespective of symbolic or non-symbolic presentation format. However, we also found distinct activation patterns for the magnitude processing of the different presentation formats. Our findings suggest that processing for the separate presentation formats is not only associated with magnitude manipulations in the IPS, but also increasing demands on executive functions and strategy use associated with frontal brain regions as well as visual attention and encoding in occipital regions. Thus, the magnitude processing of proportions may not exclusively reflect processing of number magnitude information but also rather domain-general processes.

[Alcohol-purification technology and its particle sedimentation process in manufactory of Fufang Kushen injection].

PubMed

Liu, Xiaoqian; Tong, Yan; Wang, Jinyu; Wang, Ruizhen; Zhang, Yanxia; Wang, Zhimin

2011-11-01

Fufang Kushen injection was selected as the model drug, to optimize its alcohol-purification process and understand the characteristics of particle sedimentation process, and to investigate the feasibility of using process analytical technology (PAT) on traditional Chinese medicine (TCM) manufacturing. Total alkaloids (calculated by matrine, oxymatrine, sophoridine and oxysophoridine) and macrozamin were selected as quality evaluation markers to optimize the process of Fufang Kushen injection purification with alcohol. Process parameters of particulate formed in the alcohol-purification, such as the number, density and sedimentation velocity, were also determined to define the sedimentation time and well understand the process. The purification process was optimized as that alcohol is added to the concentrated extract solution (drug material) to certain concentration for 2 times and deposited the alcohol-solution containing drug-material to sediment for some time, i.e. 60% alcohol deposited for 36 hours, filter and then 80% -90% alcohol deposited for 6 hours in turn. The content of total alkaloids was decreased a little during the depositing process. The average settling time of particles with the diameters of 10, 25 microm were 157.7, 25.2 h in the first alcohol-purified process, and 84.2, 13.5 h in the second alcohol-purified process, respectively. The optimized alcohol-purification process remains the marker compositions better and compared with the initial process, it's time saving and much economy. The manufacturing quality of TCM-injection can be controlled by process. PAT pattern must be designed under the well understanding of process of TCM production.

Application of volume-retarded osmosis and low-pressure membrane hybrid process for water reclamation.

PubMed

Im, Sung-Ju; Choi, Jungwon; Lee, Jung-Gil; Jeong, Sanghyun; Jang, Am

2018-03-01

A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated. For the FO process, a DS concentration of 0.15 g mL -1 of polysulfonate styrene (PSS) was determined to be optimal, having a high flux with a low reverse salt flux. The UF membrane with a molecular weight cut-off of 1 kDa was chosen for its high PSS rejection in the LPM process. As a single process, UF (LPM) exhibited a higher flux than FO, but this could be controlled by adjusting the effective membrane area of the FO and UF membranes in the VRO-LPM system. The VRO-LPM hybrid process only required a circulation pump for the FO process. This led to a decrease in the specific energy consumption of the VRO-LPM process for potable water production, that was similar to the single FO process. Therefore, the newly developed VRO-LPM hybrid process, with an appropriate DS selection, can be used as an energy efficient water production method, and can outperform conventional water reclamation processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quality control process improvement of flexible printed circuit board by FMEA

NASA Astrophysics Data System (ADS)

Krasaephol, Siwaporn; Chutima, Parames

2018-02-01

This research focuses on the quality control process improvement of Flexible Printed Circuit Board (FPCB), centred around model 7-Flex, by using Failure Mode and Effect Analysis (FMEA) method to decrease proportion of defective finished goods that are found at the final inspection process. Due to a number of defective units that were found at the final inspection process, high scraps may be escaped to customers. The problem comes from poor quality control process which is not efficient enough to filter defective products from in-process because there is no In-Process Quality Control (IPQC) or sampling inspection in the process. Therefore, the quality control process has to be improved by setting inspection gates and IPCQs at critical processes in order to filter the defective products. The critical processes are analysed by the FMEA method. IPQC is used for detecting defective products and reducing chances of defective finished goods escaped to the customers. Reducing proportion of defective finished goods also decreases scrap cost because finished goods incur higher scrap cost than work in-process. Moreover, defective products that are found during process can reflect the abnormal processes; therefore, engineers and operators should timely solve the problems. Improved quality control was implemented for 7-Flex production lines from July 2017 to September 2017. The result shows decreasing of the average proportion of defective finished goods and the average of Customer Manufacturers Lot Reject Rate (%LRR of CMs) equal to 4.5% and 4.1% respectively. Furthermore, cost saving of this quality control process equals to 100K Baht.

Formulating poultry processing sanitizers from alkaline salts of fatty acids

USDA-ARS?s Scientific Manuscript database

Though some poultry processing operations remove microorganisms from carcasses; other processing operations cause cross-contamination that spreads microorganisms between carcasses, processing water, and processing equipment. One method used by commercial poultry processors to reduce microbial contam...

Fabrication Process for Cantilever Beam Micromechanical Switches

DTIC Science & Technology

1993-08-01

Beam Design ................................................................... 13 B. Chemistry and Materials Used in Cantilever Beam Process...7 3. Photomask levels and composite...pp 410-413. 5 2. Cantilever Beam Fabrication Process The beam fabrication process incorporates four different photomasking levels with 62 processing

Reports of planetary geology program, 1983

NASA Technical Reports Server (NTRS)

Holt, H. E. (Compiler)

1984-01-01

Several areas of the Planetary Geology Program were addressed including outer solar system satellites, asteroids, comets, Venus, cratering processes and landform development, volcanic processes, aeolian processes, fluvial processes, periglacial and permafrost processes, geomorphology, remote sensing, tectonics and stratigraphy, and mapping.

Cognitive Processes in Discourse Comprehension: Passive Processes, Reader-Initiated Processes, and Evolving Mental Representations

ERIC Educational Resources Information Center

van den Broek, Paul; Helder, Anne

2017-01-01

As readers move through a text, they engage in various types of processes that, if all goes well, result in a mental representation that captures their interpretation of the text. With each new text segment the reader engages in passive and, at times, reader-initiated processes. These processes are strongly influenced by the readers'…

The Use of Knowledge Based Decision Support Systems in Reengineering Selected Processes in the U. S. Marine Corps

DTIC Science & Technology

2001-09-01

measurable benefit in terms of process efficiency and effectiveness, business process reengineering (BPR) is becoming increasingly important. BPR suggests...technology by businesses in hopes of achieving a measurable benefit in terms of process efficiency and effectiveness, business process...KOPER-LITE ........................................13 E. HOW MIGHT THE MILITARY BENEFIT FROM PROCESS REENGINEERING EFFORTS

30 CFR 206.181 - How do I establish processing costs for dual accounting purposes when I do not process the gas?

Code of Federal Regulations, 2010 CFR

2010-07-01

... accounting purposes when I do not process the gas? 206.181 Section 206.181 Mineral Resources MINERALS... Processing Allowances § 206.181 How do I establish processing costs for dual accounting purposes when I do not process the gas? Where accounting for comparison (dual accounting) is required for gas production...

Conceptual models of information processing

NASA Technical Reports Server (NTRS)

Stewart, L. J.

1983-01-01

The conceptual information processing issues are examined. Human information processing is defined as an active cognitive process that is analogous to a system. It is the flow and transformation of information within a human. The human is viewed as an active information seeker who is constantly receiving, processing, and acting upon the surrounding environmental stimuli. Human information processing models are conceptual representations of cognitive behaviors. Models of information processing are useful in representing the different theoretical positions and in attempting to define the limits and capabilities of human memory. It is concluded that an understanding of conceptual human information processing models and their applications to systems design leads to a better human factors approach.

Industrial application of semantic process mining

NASA Astrophysics Data System (ADS)

Espen Ingvaldsen, Jon; Atle Gulla, Jon

2012-05-01

Process mining relates to the extraction of non-trivial and useful information from information system event logs. It is a new research discipline that has evolved significantly since the early work on idealistic process logs. Over the last years, process mining prototypes have incorporated elements from semantics and data mining and targeted visualisation techniques that are more user-friendly to business experts and process owners. In this article, we present a framework for evaluating different aspects of enterprise process flows and address practical challenges of state-of-the-art industrial process mining. We also explore the inherent strengths of the technology for more efficient process optimisation.

Reliability and performance of a system-on-a-chip by predictive wear-out based activation of functional components

DOEpatents

Cher, Chen-Yong; Coteus, Paul W; Gara, Alan; Kursun, Eren; Paulsen, David P; Schuelke, Brian A; Sheets, II, John E; Tian, Shurong

2013-10-01

A processor-implemented method for determining aging of a processing unit in a processor the method comprising: calculating an effective aging profile for the processing unit wherein the effective aging profile quantifies the effects of aging on the processing unit; combining the effective aging profile with process variation data, actual workload data and operating conditions data for the processing unit; and determining aging through an aging sensor of the processing unit using the effective aging profile, the process variation data, the actual workload data, architectural characteristics and redundancy data, and the operating conditions data for the processing unit.

Fuzzy control of burnout of multilayer ceramic actuators

NASA Astrophysics Data System (ADS)

Ling, Alice V.; Voss, David; Christodoulou, Leo

1996-08-01

To improve the yield and repeatability of the burnout process of multilayer ceramic actuators (MCAs), an intelligent processing of materials (IPM-based) control system has been developed for the manufacture of MCAs. IPM involves the active (ultimately adaptive) control of a material process using empirical or analytical models and in situ sensing of critical process states (part features and process parameters) to modify the processing conditions in real time to achieve predefined product goals. Thus, the three enabling technologies for the IPM burnout control system are process modeling, in situ sensing and intelligent control. This paper presents the design of an IPM-based control strategy for the burnout process of MCAs.

Direct access inter-process shared memory

DOEpatents

Brightwell, Ronald B; Pedretti, Kevin; Hudson, Trammell B

2013-10-22

A technique for directly sharing physical memory between processes executing on processor cores is described. The technique includes loading a plurality of processes into the physical memory for execution on a corresponding plurality of processor cores sharing the physical memory. An address space is mapped to each of the processes by populating a first entry in a top level virtual address table for each of the processes. The address space of each of the processes is cross-mapped into each of the processes by populating one or more subsequent entries of the top level virtual address table with the first entry in the top level virtual address table from other processes.

Biotechnology in Food Production and Processing

NASA Astrophysics Data System (ADS)

Knorr, Dietrich; Sinskey, Anthony J.

1985-09-01

The food processing industry is the oldest and largest industry using biotechnological processes. Further development of food products and processes based on biotechnology depends upon the improvement of existing processes, such as fermentation, immobilized biocatalyst technology, and production of additives and processing aids, as well as the development of new opportunities for food biotechnology. Improvements are needed in the characterization, safety, and quality control of food materials, in processing methods, in waste conversion and utilization processes, and in currently used food microorganism and tissue culture systems. Also needed are fundamental studies of the structure-function relationship of food materials and of the cell physiology and biochemistry of raw materials.

What is a good public participation process? Five perspectives from the public.

PubMed

Webler, T; Tuler, S; Krueger, R

2001-03-01

It is now widely accepted that members of the public should be involved in environmental decision-making. This has inspired many to search for principles that characterize good public participation processes. In this paper we report on a study that identifies discourses about what defines a good process. Our case study was a forest planning process in northern New England and New York. We employed Q methodology to learn how participants characterize a good process differently, by selecting, defining, and privileging different principles. Five discourses, or perspectives, about good process emerged from our study. One perspective emphasizes that a good process acquires and maintains popular legitimacy. A second sees a good process as one that facilitates an ideological discussion. A third focuses on the fairness of the process. A fourth perspective conceptualizes participatory processes as a power struggle--in this instance a power play between local land-owning interests and outsiders. A fifth perspective highlights the need for leadership and compromise. Dramatic differences among these views suggest an important challenge for those responsible for designing and carrying out public participation processes. Conflicts may emerge about process designs because people disagree about what is good in specific contexts.

Alternating event processes during lifetimes: population dynamics and statistical inference.

PubMed

Shinohara, Russell T; Sun, Yifei; Wang, Mei-Cheng

2018-01-01

In the literature studying recurrent event data, a large amount of work has been focused on univariate recurrent event processes where the occurrence of each event is treated as a single point in time. There are many applications, however, in which univariate recurrent events are insufficient to characterize the feature of the process because patients experience nontrivial durations associated with each event. This results in an alternating event process where the disease status of a patient alternates between exacerbations and remissions. In this paper, we consider the dynamics of a chronic disease and its associated exacerbation-remission process over two time scales: calendar time and time-since-onset. In particular, over calendar time, we explore population dynamics and the relationship between incidence, prevalence and duration for such alternating event processes. We provide nonparametric estimation techniques for characteristic quantities of the process. In some settings, exacerbation processes are observed from an onset time until death; to account for the relationship between the survival and alternating event processes, nonparametric approaches are developed for estimating exacerbation process over lifetime. By understanding the population dynamics and within-process structure, the paper provide a new and general way to study alternating event processes.

Process mining in oncology using the MIMIC-III dataset

NASA Astrophysics Data System (ADS)

Prima Kurniati, Angelina; Hall, Geoff; Hogg, David; Johnson, Owen

2018-03-01

Process mining is a data analytics approach to discover and analyse process models based on the real activities captured in information systems. There is a growing body of literature on process mining in healthcare, including oncology, the study of cancer. In earlier work we found 37 peer-reviewed papers describing process mining research in oncology with a regular complaint being the limited availability and accessibility of datasets with suitable information for process mining. Publicly available datasets are one option and this paper describes the potential to use MIMIC-III, for process mining in oncology. MIMIC-III is a large open access dataset of de-identified patient records. There are 134 publications listed as using the MIMIC dataset, but none of them have used process mining. The MIMIC-III dataset has 16 event tables which are potentially useful for process mining and this paper demonstrates the opportunities to use MIMIC-III for process mining in oncology. Our research applied the L* lifecycle method to provide a worked example showing how process mining can be used to analyse cancer pathways. The results and data quality limitations are discussed along with opportunities for further work and reflection on the value of MIMIC-III for reproducible process mining research.

Research on the technique of large-aperture off-axis parabolic surface processing using tri-station machine and its applicability.

PubMed

Zhang, Xin; Luo, Xiao; Hu, Haixiang; Zhang, Xuejun

2015-09-01

In order to process large-aperture aspherical mirrors, we designed and constructed a tri-station machine processing center with a three station device, which bears vectored feed motion of up to 10 axes. Based on this processing center, an aspherical mirror-processing model is proposed, in which each station implements traversal processing of large-aperture aspherical mirrors using only two axes, while the stations are switchable, thus lowering cost and enhancing processing efficiency. The applicability of the tri-station machine is also analyzed. At the same time, a simple and efficient zero-calibration method for processing is proposed. To validate the processing model, using our processing center, we processed an off-axis parabolic SiC mirror with an aperture diameter of 1450 mm. The experimental results indicate that, with a one-step iterative process, the peak to valley (PV) and root mean square (RMS) of the mirror converged from 3.441 and 0.5203 μm to 2.637 and 0.2962 μm, respectively, where the RMS reduced by 43%. The validity and high accuracy of the model are thereby demonstrated.

Patterning of Indium Tin Oxide Films

NASA Technical Reports Server (NTRS)

Immer, Christopher

2008-01-01

A relatively rapid, economical process has been devised for patterning a thin film of indium tin oxide (ITO) that has been deposited on a polyester film. ITO is a transparent, electrically conductive substance made from a mixture of indium oxide and tin oxide that is commonly used in touch panels, liquid-crystal and plasma display devices, gas sensors, and solar photovoltaic panels. In a typical application, the ITO film must be patterned to form electrodes, current collectors, and the like. Heretofore it has been common practice to pattern an ITO film by means of either a laser ablation process or a photolithography/etching process. The laser ablation process includes the use of expensive equipment to precisely position and focus a laser. The photolithography/etching process is time-consuming. The present process is a variant of the direct toner process an inexpensive but often highly effective process for patterning conductors for printed circuits. Relative to a conventional photolithography/ etching process, this process is simpler, takes less time, and is less expensive. This process involves equipment that costs less than $500 (at 2005 prices) and enables patterning of an ITO film in a process time of less than about a half hour.

Assessment of Process Capability: the case of Soft Drinks Processing Unit

NASA Astrophysics Data System (ADS)

Sri Yogi, Kottala

2018-03-01

The process capability studies have significant impact in investigating process variation which is important in achieving product quality characteristics. Its indices are to measure the inherent variability of a process and thus to improve the process performance radically. The main objective of this paper is to understand capability of the process being produced within specification of the soft drinks processing unit, a premier brands being marketed in India. A few selected critical parameters in soft drinks processing: concentration of gas volume, concentration of brix, torque of crock has been considered for this study. Assessed some relevant statistical parameters: short term capability, long term capability as a process capability indices perspective. For assessment we have used real time data of soft drinks bottling company which is located in state of Chhattisgarh, India. As our research output suggested reasons for variations in the process which is validated using ANOVA and also predicted Taguchi cost function, assessed also predicted waste monetarily this shall be used by organization for improving process parameters. This research work has substantially benefitted the organization in understanding the various variations of selected critical parameters for achieving zero rejection.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dafler, J.R.; Sinnott, J.; Novil, M.

The first phase of a study to identify candidate processes and products suitable for future exploitation using high-temperature solar energy is presented. This phase has been principally analytical, consisting of techno-economic studies, thermodynamic assessments of chemical reactions and processes, and the determination of market potentials for major chemical commodities that use significant amounts of fossil resources today. The objective was to identify energy-intensive processes that would be suitable for the production of chemicals and fuels using solar energy process heat. Of particular importance was the comparison of relative costs and energy requirements for the selected solar product versus costs formore » the product derived from conventional processing. The assessment methodology used a systems analytical approach to identify processes and products having the greatest potential for solar energy-thermal processing. This approach was used to establish the basis for work to be carried out in subsequent phases of development. It has been the intent of the program to divide the analysis and process identification into the following three distinct areas: (1) process selection, (2) process evaluation, and (3) ranking of processes. Four conventional processes were selected for assessment namely, methanol synthesis, styrene monomer production, vinyl chloride monomer production, and terephthalic acid production.« less

An Application of X-Ray Fluorescence as Process Analytical Technology (PAT) to Monitor Particle Coating Processes.

PubMed

Nakano, Yoshio; Katakuse, Yoshimitsu; Azechi, Yasutaka

2018-06-01

An attempt to apply X-Ray Fluorescence (XRF) analysis to evaluate small particle coating process as a Process Analytical Technologies (PAT) was made. The XRF analysis was used to monitor coating level in small particle coating process with at-line manner. The small particle coating process usually consists of multiple coating processes. This study was conducted by a simple coating particles prepared by first coating of a model compound (DL-methionine) and second coating by talc on spherical microcrystalline cellulose cores. The particles with two layered coating are enough to demonstrate the small particle coating process. From the result by the small particle coating process, it was found that the XRF signal played different roles, resulting that XRF signals by first coating (layering) and second coating (mask coating) could demonstrate the extent with different mechanisms for the coating process. Furthermore, the particle coating of the different particle size has also been investigated to evaluate size effect of these coating processes. From these results, it was concluded that the XRF could be used as a PAT in monitoring particle coating processes and become powerful tool in pharmaceutical manufacturing.

Single-Run Single-Mask Inductively-Coupled-Plasma Reactive-Ion-Etching Process for Fabricating Suspended High-Aspect-Ratio Microstructures

NASA Astrophysics Data System (ADS)

Yang, Yao-Joe; Kuo, Wen-Cheng; Fan, Kuang-Chao

2006-01-01

In this work, we present a single-run single-mask (SRM) process for fabricating suspended high-aspect-ratio structures on standard silicon wafers using an inductively coupled plasma-reactive ion etching (ICP-RIE) etcher. This process eliminates extra fabrication steps which are required for structure release after trench etching. Released microstructures with 120 μm thickness are obtained by this process. The corresponding maximum aspect ratio of the trench is 28. The SRM process is an extended version of the standard process proposed by BOSCH GmbH (BOSCH process). The first step of the SRM process is a standard BOSCH process for trench etching, then a polymer layer is deposited on trench sidewalls as a protective layer for the subsequent structure-releasing step. The structure is released by dry isotropic etching after the polymer layer on the trench floor is removed. All the steps can be integrated into a single-run ICP process. Also, only one mask is required. Therefore, the process complexity and fabrication cost can be effectively reduced. Discussions on each SRM step and considerations for avoiding undesired etching of the silicon structures during the release process are also presented.

Auditory-musical processing in autism spectrum disorders: a review of behavioral and brain imaging studies.

PubMed

Ouimet, Tia; Foster, Nicholas E V; Tryfon, Ana; Hyde, Krista L

2012-04-01

Autism spectrum disorder (ASD) is a complex neurodevelopmental condition characterized by atypical social and communication skills, repetitive behaviors, and atypical visual and auditory perception. Studies in vision have reported enhanced detailed ("local") processing but diminished holistic ("global") processing of visual features in ASD. Individuals with ASD also show enhanced processing of simple visual stimuli but diminished processing of complex visual stimuli. Relative to the visual domain, auditory global-local distinctions, and the effects of stimulus complexity on auditory processing in ASD, are less clear. However, one remarkable finding is that many individuals with ASD have enhanced musical abilities, such as superior pitch processing. This review provides a critical evaluation of behavioral and brain imaging studies of auditory processing with respect to current theories in ASD. We have focused on auditory-musical processing in terms of global versus local processing and simple versus complex sound processing. This review contributes to a better understanding of auditory processing differences in ASD. A deeper comprehension of sensory perception in ASD is key to better defining ASD phenotypes and, in turn, may lead to better interventions. © 2012 New York Academy of Sciences.

Discrete State Change Model of Manufacturing Quality to Aid Assembly Process Design

NASA Astrophysics Data System (ADS)

Koga, Tsuyoshi; Aoyama, Kazuhiro

This paper proposes a representation model of the quality state change in an assembly process that can be used in a computer-aided process design system. In order to formalize the state change of the manufacturing quality in the assembly process, the functions, operations, and quality changes in the assembly process are represented as a network model that can simulate discrete events. This paper also develops a design method for the assembly process. The design method calculates the space of quality state change and outputs a better assembly process (better operations and better sequences) that can be used to obtain the intended quality state of the final product. A computational redesigning algorithm of the assembly process that considers the manufacturing quality is developed. The proposed method can be used to design an improved manufacturing process by simulating the quality state change. A prototype system for planning an assembly process is implemented and applied to the design of an auto-breaker assembly process. The result of the design example indicates that the proposed assembly process planning method outputs a better manufacturing scenario based on the simulation of the quality state change.