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https://www.readbyqxmd.com/read/28641260/nested-conjugate-gradient-algorithm-with-nested-preconditioning-for-non-linear-image-restoration
#1
Deepak G Skariah, Muthuvel Arigovindan
We develop a novel optimization algorithm, which we call Nested Non-Linear Conjugate Gradient algorithm (NNCG), for image restoration based on quadratic data fitting and smooth non-quadratic regularization. The algorithm is constructed as a nesting of two conjugate gradient (CG) iterations. The outer iteration is constructed as a preconditioned non-linear CG algorithm; the preconditioning is performed by the inner CG iteration that is linear. The inner CG iteration, which performs preconditioning for outer CG iteration, itself is accelerated by an another FFT based non-iterative preconditioner...
June 19, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28641256/a-novel-fast-tensor-based-preconditioner-for-image-restoration
#2
Mansoor Rezghi
Image restoration is one of the main parts of image processing. Mathematically, this problem can be modeled as a large scale structured ill-posed linear system. Ill-posedness of this problem results in low convergence rate of iterative solvers. For speeding up the convergence, preconditioning usually is used. Despite the existing preconditioners for image restoration which are constructed based on approximations of the blurring matrix, in this paper, we propose a novel preconditioner with a different viewpoint...
June 16, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28636928/neurovascular-toxicity-of-n-methyl-d-aspartate-is-markedly-enhanced-in-the-developing-mouse-central-nervous-system
#3
Sudhakar Vadivelu, Kui Xu, Vanja Tolj, Rahul Rege, Lindsay Darkins, Karthik Vishwanath
Penumbral perfusion is critical to brain viability. Proximal arterial occlusion and deep brain stroke has variable effect on cortical dysfunction. Cortical microvessel collaterals may be recruited and at times sufficient for partial parenchymal perfusion. Postnatal neural and endothelial cells are markedly vulnerable to glutamate excitotoxicity. Early vascular cell stress may promote partial protective neural preconditioning though postnatally a developmental window of the cerebral microvasculature may be particularly vulnerable to injury...
June 18, 2017: Neuroscience Letters
https://www.readbyqxmd.com/read/28635661/hypoxic-preconditioning-promotes-the-bioactivities-of-mesenchymal-stem-cells-via-the-hif-1%C3%AE-grp78-akt-axis
#4
Jun Hee Lee, Yeo Min Yoon, Sang Hun Lee
Mesenchymal stem cells (MSC) are ideal materials for stem cell-based therapy. As MSCs reside in hypoxic microenvironments (low oxygen tension of 1% to 7%), several studies have focused on the beneficial effects of hypoxic preconditioning on MSC survival; however, the mechanisms underlying such effects remain unclear. This study aimed to uncover the potential mechanism involving 78-kDa glucose-regulated protein (GRP78) to explain the enhanced MSC bioactivity and survival in hindlimb ischemia. Under hypoxia (2% O₂), the expression of GRP78 was significantly increased via hypoxia-inducible factor (HIF)-1α...
June 21, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28631530/intentional-preparation-of-auditory-attention-switches-explicit-cueing-and-sequential-switch-predictability
#5
Julia C Seibold, Sophie Nolden, Josefa Oberem, Janina Fels, Iring Koch
In an auditory attention-switching paradigm, participants heard two simultaneously spoken number-words, each presented to one ear, and decided if the target number was smaller or larger than five by pressing a left or right key. An instructional cue in each trial indicated which feature had to be used to identify the target-number (e.g. female voice). Auditory attention-switch costs were found when this feature changed compared to when it repeated in two consecutive trials. Earlier studies employing this paradigm showed mixed results when they examined whether such cued auditory attention-switches can be prepared actively during the cue-stimulus-interval...
June 20, 2017: Quarterly Journal of Experimental Psychology: QJEP
https://www.readbyqxmd.com/read/28631503/exercise-induced-cardioprotection-and-the-therapeutic-potential-of-ripc
#6
John C Quindry
In the search for innovative solutions to treat ischemic heart disease, recent basic science and clinical approaches have focused on remote ischemic preconditioning (RIPC). Remote ischemic preconditioning involves short intervals of limb blood flow occlusion by the application of a blood pressure cuff inflated to a suprasystolic pressure. The promise of RIPC in the development of new cardioprotective therapies is founded on the premise that it is cost-effective, technically simple, and overcomes many logistical and biochemical hurdles associated with other ischemic preconditioning approaches...
January 1, 2017: Journal of Cardiovascular Pharmacology and Therapeutics
https://www.readbyqxmd.com/read/28627606/effects-of-ischemic-preconditioning-on-pdgf-bb-expression-in-the-gerbil-hippocampal-ca1-region-following-transient-cerebral-ischemia
#7
Jae-Chul Lee, Yang Hee Kim, Tae-Kyeong Lee, In Hye Kim, Jeong Hwi Cho, Geum-Sil Cho, Bich-Na Shin, Joon Ha Park, Ji Hyeon Ahn, Myoung Cheol Shin, Jun Hwi Cho, Il Jun Kang, Moo-Ho Won, Jeong Yeol Seo
Ischemic preconditioning (IPC) is induced by exposure to brief durations of transient ischemia, which results in ischemic tolerance to a subsequent longer or lethal period of ischemia. In the present study, the effects of IPC (2 min of transient cerebral ischemia) were examined on immunoreactivity of platelet‑derived growth factor (PDGF)‑BB and on neuroprotection in the gerbil hippocampal CA1 region following lethal transient cerebral ischemia (LTCI; 5 min of transient cerebral ischemia). IPC was subjected to a 2‑min sublethal ischemia and a LTCI was given 5‑min transient ischemia...
June 19, 2017: Molecular Medicine Reports
https://www.readbyqxmd.com/read/28627174/integrative-analysis-of-renal-ischemia-reperfusion-injury-and-remote-ischemic-preconditioning-in-mice
#8
Kumsun Cho, Sang-Il Min, Sanghyun Ahn, Seung-Kee Min, Curie Ahn, Kyung-Sang Yu, In-Jin Jang, Joo-Youn Cho, Jongwon Ha
Remote ischemic preconditioning (RIPC) is a strategy to induce resistance in a target organ against the oxidative stress and injury caused by ischemia and reperfusion (IR). RIPC harnesses the body's endogenous protective capabilities through brief episodes of IR applied in organs remote from the target. Few studies have analyzed this phenomenon in the kidney. Furthermore, the window of protection representing RIPC efficacy has not been fully elucidated. Here, we performed a multi-omics study to specify those associated with protective effects of RIPC against the IR injury...
June 19, 2017: Journal of Proteome Research
https://www.readbyqxmd.com/read/28625317/sphingosine-1-phosphate-postconditioning-protects-against-myocardial-ischemia-reperfusion-injury-in-rats-via-mitochondrial-signaling-and-akt-gsk3%C3%AE-phosphorylation
#9
Rui Fang, Lu-Lu Zhang, Li-Zhi Zhang, Wenchang Li, Mengmeng Li, Ke Wen
BACKGROUND AND AIMS: Although preconditioning of sphingosine 1-phosphate (S1P) has been shown to protect myocytes from hypoxia reoxgenation injury in vitro, the role of S1P postconditioning on myocardial ischemia reperfusion injury (MIRI) in vivo and its related mechanism are unknown. The aim of this study was to investigate the protective role of sphingosine 1-phosphate (S1P) postconditioning in MIRI via its effects on mitochondrial signaling and Akt/Gsk3β phosphorylation. METHODS: Rats were subjected to MIRI, consisting of 30 min of ischemia followed by 120 min of reperfusion, with S1P administered at the beginning of the reperfusion...
February 2017: Archives of Medical Research
https://www.readbyqxmd.com/read/28624831/chelerythrine-attenuates-renal-ischemia-reperfusion-induced-myocardial-injury-by-activating-cse-h2s-via-pkc-nf-%C3%AE%C2%BAb-pathway-in-diabetic-rats
#10
Bo Hu, Guangtao Xu, Yongxia Zheng, Fei Tong, Ping Qian, Xiaoyan Pan, Xinmei Zhou, Ruilin Shen
BACKGROUND/AIMS: Chelerythrine (CHE), a benzophenanthridine alkaloid, is a potent, selective, and cell-permeable protein kinase C (PKC) inhibitor. The purpose of the present study was to evaluate the effect of CHE on myocardial recovery after renal ischemia/reperfusion (I/R)-induced myocardial injury (RI/RMI) in a streptozocin (STZ)-induced diabetic rat model. METHODS: Diabetes mellitus (DM) rats preconditioned with CHE and D, L-propargylglycine (PAG) were subjected to renal I/R...
2017: Kidney & Blood Pressure Research
https://www.readbyqxmd.com/read/28624830/activation-of-nrf2-ho-1-pathway-by-glycogen-synthase-kinase-3%C3%AE-inhibition-attenuates-renal-ischemia-reperfusion-injury-in-diabetic-rats
#11
Xiaohua Shen, Bo Hu, Guangtao Xu, Fengjuan Chen, Ruifen Ma, Nenghua Zhang, Jie Liu, Xiaoqin Ma, Jia Zhu, Yuhong Wu, Ruilin Shen
BACKGROUND/AIMS: Diabetes mellitus can exacerbate renal ischemia-reperfusion (I/R) injury (RI/RI). The aim of the present study was to evaluate the protective effect of GSK-3β inhibition (TDZD-8) on I/R-induced renal injury through the Nrf2/HO-1 pathway in a streptozocin (STZ)-induced diabetic rat model. METHODS: STZ-induced diabetic rats preconditioned with TDZD-8 and ZnPP were subjected to renal I/R. The extent of renal morphologic lesions. Renal function was assessed from blood urea nitrogen (BUN) and serum creatinine (Scr), as determined utlizing commercial kits...
2017: Kidney & Blood Pressure Research
https://www.readbyqxmd.com/read/28624055/sevoflurane-preconditioning-protects-from-posttransplant-injury-in-mouse-lung-transplantation
#12
Yoshito Yamada, Isabelle Laube, Jae-Hwi Jang, John M Bonvini, Ilhan Inci, Walter Weder, Beatrice Beck Schimmer, Wolfgang Jungraithmayr
BACKGROUND: Although sevoflurane (Sevo) had been shown to ameliorate posttransplant injury in various organs, data available are inconsistent, particularly in the context of lung transplantation (Tx). We here investigated if preconditioning by Sevo can protect from posttransplant injury regarding both, primary graft dysfunction (PGD) and acute rejection (AR) after experimental lung Tx, thereby focusing on two important clinical outcome parameters. MATERIALS AND METHODS: Three experimental approaches were used: (1) BALB/c mice were preconditioned for 2 h with Sevo or a fentanyl cocktail (Control; n = 10); (2) syngeneic (Syn) mouse lung Tx (C57BL/6) with a Sevo-preconditioned graft followed by 18 h storage to mimic PGD (Syn-Tx, n = 12) versus controls (fentanyl cocktail); and (3) allogeneic (Allo) Tx (BALB/c, donor; C57BL/6, recipient) to mimic AR (Allo-Tx, n = 12) versus controls (fentanyl cocktail)...
June 15, 2017: Journal of Surgical Research
https://www.readbyqxmd.com/read/28622640/clinical-course-and-core-variability-in-hbv-infected-patients-without-detectable-anti-hbc-antibodies
#13
Olympia E Anastasiou, Marek Widera, Jens Verheyen, Johannes Korth, Guido Gerken, Fabian A Helfritz, Ali Canbay, Heiner Wedemeyer, Sandra Ciesek
BACKGROUND: The presence of anti-HBc antibodies indicates direct encounter of the immune system with hepatitis B virus (HBV). OBJECTIVES: Aim of our study was to seek for anti-HBc negative but HBV replicating patients and analyze their clinical course and preconditions. STUDY DESIGN: From 1568 HBV-DNA positive patients, 29 patients (1.85%) tested negative for anti-HBc. The absence of anti-HBc could be confirmed in 19 patients using an alternative assay...
June 8, 2017: Journal of Clinical Virology: the Official Publication of the Pan American Society for Clinical Virology
https://www.readbyqxmd.com/read/28622203/crucial-points-for-analysis-of-ischemic-preconditioning-in-sports-and-exercise
#14
Moacir Marocolo, Hans-Joachim Appell Coriolano, Carlos Alberto-Júnior Mourão, Gustavo Ribeiro da Mota
No abstract text is available yet for this article.
July 2017: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/28622067/opioid-involved-overdose-among-male-afghanistan-iraq-era-u-s-military-veterans-a-multidimensional-perspective
#15
Alex S Bennett, Luther Elliott, Andrew Golub, Brett Wolfson-Stofko, Honoria Guarino
BACKGROUND: Mirroring nationwide trends in a broad range of U.S. populations, an alarming number of Afghanistan/Iraq-era U.S. Military veterans have experienced opioid-related overdoses. A growing body of research has examined the proximal behaviors that can precipitate an overdose; considerably less is known about more distal physiological, psychosocial and structural influences on these risk behaviors. OBJECTIVES: This study adopts a multidimensional approach to better understand opioid-related overdose among U...
June 16, 2017: Substance Use & Misuse
https://www.readbyqxmd.com/read/28616759/is-dual-semitendinosus-allograft-stronger-than-turndown-for-achilles-tendon-reconstruction-an-in-vitro-analysis
#16
Michael C Aynardi, Lara C Atwater, Roshan Melvani, Brent G Parks, Adrian G Paez, Stuart D Miller
BACKGROUND: Large Achilles tendon defects pose a treatment challenge. The standard treatment with a turndown flap requires a large extensile incision, puts the sural nerve at risk, and demands slow, careful rehabilitation. Dual allograft semitendinosus reconstruction is a new clinical alternative that has the theoretical advantages of a smaller incision, less dissection, and a stronger construct that may allow for faster rehabilitation. QUESTIONS/PURPOSES: In a cadaver biomechanical model, we compared the dual allograft semitendinosus reconstruction with the myofascial turndown in terms of (1) mechanical strength and resistance to deformation and (2) failure mechanisms in reconstruction of large segmental Achilles defects...
June 14, 2017: Clinical Orthopaedics and related Research
https://www.readbyqxmd.com/read/28616210/acute-kidney-injury-an-overview-of-diagnostic-methods-and-clinical-management
#17
Daniel Hertzberg, Linda Rydén, John W Pickering, Ulrik Sartipy, Martin J Holzmann
Acute kidney injury (AKI) is a common condition in multiple clinical settings. Patients with AKI are at an increased risk of death, over both the short and long term, and of accelerated renal impairment. As the condition has become more recognized and definitions more unified, there has been a rapid increase in studies examining AKI across many different clinical settings. This review focuses on the classification, diagnostic methods and clinical management that are available, or promising, for patients with AKI...
June 2017: Clinical Kidney Journal
https://www.readbyqxmd.com/read/28615010/internet-based-perioperative-exercise-program-in-patients-with-barrett-s-carcinoma-scheduled-for-esophagectomy-ipep-study-a-prospective-randomized-controlled-trial
#18
Daniel Pfirrmann, Suzan Tug, Oana Brosteanu, Matthias Mehdorn, Martin Busse, Peter P Grimminger, Florian Lordick, Torben Glatz, Jens Hoeppner, Hauke Lang, Perikles Simon, Ines Gockel
BACKGROUND: Patients undergoing surgery for esophageal cancer have a high risk for postoperative deterioration of lung function and pulmonary complications. This is partly due to one-lung ventilation during thoracotomy. This often accounts for prolonged stay on intensive care units, delayed postoperative reconvalescence and reduced quality of life. Socioeconomic disadvantages can result from these problems. Physical preconditioning has become a crucial leverage to optimize fitness and lung function in patients scheduled for esophagectomy, in particular during the time period of neoadjuvant therapy...
June 14, 2017: BMC Cancer
https://www.readbyqxmd.com/read/28611938/anatomic-study-of-the-vascular-perfusion-of-the-sternum-and-its-clinical-relevance-in-deep-sternal-wound-infection
#19
Nick Spindler, Florian Kaatz, Christine Feja, Christian Etz, Friedrich-Wilhelm Mohr, Ingo Bechmann, Christoph Josten, Stefan Langer, Sabine Loeffler
Introduction: Deep sternal wound infections (DSWI) are a rare but devastating complication after median sternotomy. Minor perfusion in bone and soft tissue, especially after recruiting the internal mammary artery for bypass supports the development of wound infection and nonunion of the sternal bone. The aim of the study was the macroscopic and radiological presentation of the vascular system supplying the sternum, in particular the compensating blood supply routes in the event that the internal mammary artery is no longer available after use as a bypass vessel...
2017: GMS Interdisciplinary Plastic and Reconstructive Surgery DGPW
https://www.readbyqxmd.com/read/28610694/preconditioned-alternating-projection-algorithm-for-solving-the-penalized-likelihood-spect-reconstruction-problem
#20
Si Li, Jiahan Zhang, Andrzej Krol, C Ross Schmidtlein, David Feiglin, Yuesheng Xu
PURPOSE: The authors recently developed a preconditioned alternating projection algorithm (PAPA) for solving the penalized-likelihood SPECT reconstruction problem. The proposed algorithm can solve a wide variety of non-differentiable optimization models. This work is dedicated to comparing the performance of PAPA with total variation (TV) regularization (TV-PAPA) and a novel forward-backward algorithm with nested expectation maximization (EM)-TV iteration scheme (FB-EM-TV). METHODS: Monte Carlo technique was used to simulate multiple noise realizations of the fan-beam collimated SPECT data for a piecewise constant phantom with warm background, and hot and cold spheres with uniform activities at two noise levels...
June 2017: Physica Medica: PM
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