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Sega M, Kantorovich SS, Holm C, Arnold A. Communication: Kinetic and pairing contributions in the dielectric spectra of electrolyte solutions. J Chem Phys 2015; 140:211101. [PMID: 24907981 DOI: 10.1063/1.4880237] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In the late 1970s, Hubbard and Onsager predicted that adding salt to a polar solution would result in a reduced dielectric permittivity that arises from the unexpected tendency of solvent dipoles to align opposite to the applied field. Here we develop a novel non-equilibrium molecular dynamics simulation approach to determine this decrement accurately. Using a thermodynamic consistent all-atom force field we show that for an aqueous solution containing sodium chloride around 4.8 mol/l, this effect accounts for 12% of the total dielectric permittivity. The dielectric decrement can be strikingly different if a less accurate force field for the ions is used. Using the widespread GROMOS parameters, we observe in fact an increment of the dielectric permittivity rather than a decrement, caused by ion pairing and introduced by a too low dispersion force.
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Eastwood C, Arnold A, Harris K, Miller R, Savell J. Impact of multiple antimicrobial interventions on ground beef quality. Meat Sci 2015. [DOI: 10.1016/j.meatsci.2014.09.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Kron T, Dwyer M, Smith L, MacDonald A, Pawsey M, Raik E, Arnold A, Hill B, Duchesne GM. The development of practice standards for radiation oncology in Australia: a tripartite approach. Clin Oncol (R Coll Radiol) 2015; 27:325-9. [PMID: 25669589 DOI: 10.1016/j.clon.2015.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 01/07/2015] [Accepted: 01/08/2015] [Indexed: 10/24/2022]
Abstract
In many areas of health care, practice standards have become an accepted method for professions to assess and improve the quality of care delivery. The aim of this work is to present the development of practice standards for radiation oncology in Australia, highlighting critical points and lessons learned. Following a review of radiotherapy services in Australia, a multidisciplinary group with support from the Australian Government developed practice standards for radiation oncology in Australia. The standards were produced in a multistep process including a nationwide survey of radiotherapy centres and piloting of the standards in a representative subset of all Australian radiotherapy centres. The standards are grouped into three sections: Facility management (covering staffing, data management, equipment and processes); Treatment planning and delivery (providing more detailed guidance on prescription, planning and delivery); Safety and quality management (including radiation safety, incident monitoring and clinical trials participation). Each of the 16 standards contains specific criteria, a commentary and suggestions for the evidence required to demonstrate compliance. The development of the standards was challenging and time consuming, but the collaborative efforts of the professions resulted in standards applicable throughout Australia and possibly further afield.
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Arnold A, Calvetti D, Gjedde A, Iversen P, Somersalo E. Astrocytic tracer dynamics estimated from [1-¹¹C]-acetate PET measurements. MATHEMATICAL MEDICINE AND BIOLOGY-A JOURNAL OF THE IMA 2014; 32:367-82. [PMID: 25424579 DOI: 10.1093/imammb/dqu021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 10/08/2014] [Indexed: 11/14/2022]
Abstract
We address the problem of estimating the unknown parameters of a model of tracer kinetics from sequences of positron emission tomography (PET) scan data using a statistical sequential algorithm for the inference of magnitudes of dynamic parameters. The method, based on Bayesian statistical inference, is a modification of a recently proposed particle filtering and sequential Monte Carlo algorithm, where instead of preassigning the accuracy in the propagation of each particle, we fix the time step and account for the numerical errors in the innovation term. We apply the algorithm to PET images of [1-¹¹C]-acetate-derived tracer accumulation, estimating the transport rates in a three-compartment model of astrocytic uptake and metabolism of the tracer for a cohort of 18 volunteers from 3 groups, corresponding to healthy control individuals, cirrhotic liver and hepatic encephalopathy patients. The distribution of the parameters for the individuals and for the groups presented within the Bayesian framework support the hypothesis that the parameters for the hepatic encephalopathy group follow a significantly different distribution than the other two groups. The biological implications of the findings are also discussed.
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Barlin J, Arnold A, Mobley S, Otegbeye E, Stadler Z, Robson M, Offit K, Barakat R, Kauff N. Breast cancer risk with hormone replacement after risk-reducing salpingo-oophorectomy in BRCA mutation carriers: Does it abrogate the benefit? Gynecol Oncol 2014. [DOI: 10.1016/j.ygyno.2014.03.213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Pestell RG, Casimiro MC, Crosariol M, Loro E, Dampier W, Di Sante G, Ertel A, Yu Z, Saria EA, Papanikolaou A, Li Z, Wang C, Addya S, Lisanti MP, Fortina P, Tozeren A, Knudsen ES, Arnold A. Abstract P5-07-06: Kinase-independent role of cyclin D1 in chromosomal instability and mammary tumorigenesis. Cancer Res 2013. [DOI: 10.1158/0008-5472.sabcs13-p5-07-06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Cyclin D1 is an important molecular driver of human breast cancer but better understanding of its oncogenic mechanisms is needed, especially to enhance efforts in targeted therapeutics. Activation of the cyclin D1 oncogene, often by amplification or rearrangement, is a major driver of multiple types of human tumors including breast and squamous cell cancers, B-cell lymphoma, myeloma, and parathyroid adenoma. The cyclin D1 gene is amplified or overexpressed in up to half of human breast cancers and its mammary-targeted overexpression induces mammary tumorigenesis in mice. Cyclin D1 encodes the regulatory subunit of the cyclin-dependent kinase (CDK) holoenzyme that phosphorylates several substrates including the retinoblastoma protein (pRb) to advance the G1S cell cycle checkpoint, promote DNA synthesis and regulate NRF-1 to inhibit mitochondrial biogenesis thereby coordinating nuclear and mitochondrial functions.
In addition to cyclin D1's function as a regulatory subunit of a CDK holoenzyme, several CDK-independent functions have been identified. Tumors overexpressing cyclin D1 tend to display normal levels of proliferation and expression of E2F target genes, which contrasts with tumors overexpressing cyclin E or an activator for pRb. Breast cancers overexpressing cyclin D1 that are wild type for pRb have relatively normal proliferation rates, in contrast to those caused by genetic inactivation of pRb, which show significantly increased proliferation rates. Furthermore, the alternate splice form of cyclin D1, (cyclin D1b), has potent transforming ability, which does not correlate with the ability to phosphorylate the pRb protein. Several other properties of cyclin D1 have been identified including the induction of cellular migration and enhanced angiogenesis, inhibition of mitochondrial biogenesis, and mediating DNA-damage repair signaling. Cyclin D1 binding proteins participating in these putatively CDK-independent functions include PACSIN2, NRF1, and p27KIP1; binding to p27KIP1 and PACSIN2 contribute to the pro-migratory function of cyclin D1.
Currently, pharmaceutical initiatives to inhibit cyclin D1 are focused on the catalytic component since the transforming capacity is thought to reside in the cyclin D1/CDK activity. We initiated the following study to directly test the oncogenic potential of catalytically inactive cyclin D1 in an in vivo mouse model that is relevant to breast cancer. Herein, transduction of cyclin D1-/- mouse embryonic fibroblasts (MEFs) with the kinase dead KE mutant of cyclin D1 led to aneuploidy, abnormalities in mitotic spindle formation, autosome amplification, and chromosomal instability (CIN) by gene expression profiling. Acute transgenic expression of either cyclin D1WT or cyclin D1KE in the mammary gland was sufficient to induce the CIN signature within 7 days. Sustained expression of cyclin D1KE induced mammary adenocarcinoma with similar kinetics to that of the wild-type cyclin D1. ChIP-Seq studies demonstrated recruitment of cyclin D1WT and cyclin D1KE to the genes governing CIN. We conclude that the CDK-activating function of cyclin D1 is not necessary to induce either chromosomal instability or mammary tumorigenesis.
Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-07-06.
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Köddermann T, Reith D, Arnold A. Why the Partition Coefficient of Ionic Liquids Is Concentration-Dependent. J Phys Chem B 2013; 117:10711-8. [DOI: 10.1021/jp405383f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Koeddermann T, Reith D, Arnold A. Accurate Calculations of Partition Coefficients (log POW and log PMW) with Atomistic Simulation Methods. CHEM-ING-TECH 2013. [DOI: 10.1002/cite.201250733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ali A, Goffin J, Arnold A, Ellis P. Survival of patients with non-small-cell lung cancer after a diagnosis of brain metastases. Curr Oncol 2013; 20:e300-6. [PMID: 23904768 PMCID: PMC3728058 DOI: 10.3747/co.20.1481] [Citation(s) in RCA: 146] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND The prognosis of patients with brain metastases from non-small-cell lung cancer (nsclc) is poor. However, some reports suggest that patients with brain metastases at the time of initial diagnosis have a more favourable survival than do patients with advanced nsclc without brain metastases. METHODS In a retrospective cohort of all new lung cancer patients seen at a Canadian tertiary centre between July 2005 and June 2007, we examined survival after a diagnosis of brain metastases for patients with brain metastases at initial diagnosis and patients who developed brain metastases later in their illness. RESULTS During the 2-year period, 91 of 878 patients (10.4%) developed brain metastases. Median age in this cohort was 64 years. In 45, brain metastases were present at initial diagnosis, and in 46, brain metastases developed later in the course of the illness. Median survival in the entire cohort was 7.8 months. Survival after the diagnosis of brain metastases was similar for patients with brain metastases at diagnosis and later in the illness (4.8 months vs. 3.7 months, p = 0.53). As a result, patients who developed brain metastases later in their illness had a longer overall survival than did patients with brain metastases at diagnosis (9.8 months vs. 4.8 months). Among patients who received chemotherapy, the survival of patients with brain metastases at diagnosis was still poor (6.2 months). CONCLUSIONS Our data show limited survival in patients with brain metastases from nsclc. Careful patient selection for more aggressive treatment approaches is necessary.
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Brömme J, Schmücking M, Arnold A, Giger R, Rauch D, Leiser D, Plasswilm L, Geretschläger A, Ghadjar P, Aebersold D. Taxane-containing induction chemotherapy followed by definitive chemoradiotherapy. Strahlenther Onkol 2013; 189:618-24. [DOI: 10.1007/s00066-013-0397-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 05/22/2013] [Indexed: 10/26/2022]
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Barlin J, Pike M, Otegbeye E, Arnold A, Stadler Z, Robson M, Aghajanian C, Offit K, Barakat R, Kauff N. Does postmenopausal risk-reducing salpingo-oophorectomy reduce the risk of BRCA-associated breast cancer? Gynecol Oncol 2013. [DOI: 10.1016/j.ygyno.2013.04.304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Long K, Pike M, Otegbeye E, Arnold A, Stadler Z, Robson M, Barakat R, Offit K, Chi D, Kauff N. Cancer risks in women from BRCA-negative hereditary breast and ovarian cancer families. Gynecol Oncol 2013. [DOI: 10.1016/j.ygyno.2013.04.308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Arnold A, Nikoloski Z. Comprehensive classification and perspective for modelling photorespiratory metabolism. PLANT BIOLOGY (STUTTGART, GERMANY) 2013; 15:667-75. [PMID: 23573904 DOI: 10.1111/j.1438-8677.2012.00708.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 10/25/2012] [Indexed: 05/03/2023]
Abstract
Biological processes involved in photorespiratory and photosynthetic metabolism operate concurrently and affect the interplay between carbon and nitrogen assimilation reflected in plant growth. Experimental evidence has indicated that photorespiratory metabolism has a wide-ranging influence not only on other principal metabolic pathways but also on a multitude of signalling cascades. Therefore, accurate quantitative models of photorespiration can provide a means for predicting and in silico probing of plant behaviour at various levels of the system. We first present a comprehensive classification of current models of photorespiratory metabolism developed within the existing carbon-centric modelling paradigm. We then offer a perspective for modelling photorespiratory metabolism by considering the coupling of carbon and nitrogen metabolism in the context of compartmentalised, genome-scale metabolic models of C3 plants. In addition, we outline the challenges stemming from the need to consider plant metabolic and signalling pathways in assessing the still controversial role of photorespiration and to confront the devised models with the ever-increasing amounts of high-throughput data.
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Davies AR, Ruggles R, Young Y, Clark H, Reddell P, Verlander NQ, Arnold A, Maguire H. Salmonella enterica serovar Enteritidis phage type 4 outbreak associated with eggs in a large prison, London 2009: an investigation using cohort and case/non-case study methodology. Epidemiol Infect 2013; 141:931-40. [PMID: 22800644 PMCID: PMC9151890 DOI: 10.1017/s0950268812001458] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 05/18/2012] [Accepted: 06/10/2012] [Indexed: 11/07/2022] Open
Abstract
In September 2009, an outbreak of Salmonella enterica serovar Enteritidis affected 327 of 1419 inmates at a London prison. We applied a cohort design using aggregated data from the kitchen about portions of food distributed, aligned this with individual food histories from 124 cases (18 confirmed, 106 probable) and deduced the exposures of those remaining well. Results showed that prisoners eating egg cress rolls were 26 times more likely to be ill [risk ratio 25.7, 95% confidence interval (CI) 15.5-42.8, P<0.001]. In a case/non-case multivariable analysis the adjusted odds ratio for egg cress rolls was 41.1 (95% CI 10.3-249.7, P<0.001). The epidemiological investigation was strengthened by environmental and microbiological investigations. This paper outlines an approach to investigations in large complex settings where aggregate data for exposures may be available, and led to the development of guidelines for the management of future gastrointestinal outbreaks in prison settings.
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Ghadjar P, Bojaxihu B, Arnold A, Hallermann W, Aebersold D, Geretschläger A. EP-1167 POSTOPERATIVE INTENSITY MODULATED RADIOTHERAPY IN HIGH RISK OR LOCALLY ADVANCED ORAL CAVITY CANCER. Radiother Oncol 2012. [DOI: 10.1016/s0167-8140(12)71500-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Nauer CB, Rieke A, Zubler C, Candreia C, Arnold A, Senn P. Low-dose temporal bone CT in infants and young children: effective dose and image quality. AJNR Am J Neuroradiol 2011; 32:1375-80. [PMID: 21757514 DOI: 10.3174/ajnr.a2524] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND AND PURPOSE The temporal bone is ideal for low-dose CT because of its intrinsic high contrast. The aim of this study was to retrospectively evaluate image quality and radiation doses of a new low-dose versus a standard high-dose pediatric temporal bone CT protocol and to review dosimetric data from the literature. MATERIALS AND METHODS Image quality and radiation doses were compared for 38 low-dose (80 kV/90-110 mAs) and 16 high-dose (140 kV/170 mAs) temporal bone CT scans of infants to 5-year-old children. The CT visualization quality of 23 middle and inner ear structures was subjectively graded by 3 neuroradiologists and 3 otologists by using a 5-point scale with scores 1-2 indicating insufficient and scores 3-5 indicating sufficient image quality. Effective doses of local and literature-derived protocols were calculated from dosimetric data by using NRPB-SR250 software. RESULTS Insufficient image-quality scores were more frequent in low-dose scans versus high-dose scans, but the difference was only statistically significant for otologists (6.0% versus 3.4%, P = .004) and not for neuroradiologists (1.2% versus 0.7%, P = .84). Image quality was critical for small structures (such as the stapes or lamella at the internal auditory canal fundus). Effective doses were 0.25-0.3 mSv for low-dose scans, 1.4-1.8 mSv for high-dose scans, and 0.9-2.6 mSv for literature-derived protocols. CONCLUSIONS The image quality of the new low-dose protocol remains diagnostic for assessing middle and inner ear anatomy despite a 3- to 8-fold dose reduction over previous and literature-derived protocols. However, image quality of small structures is critical and may be perceived as insufficient.
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Swartzendruber A, Niccolai L, Zenilman J, Jennings J, Sipsma H, Arnold A, Kershaw T. P2-S1.14 The accuracy of perceptions about sexual concurrency among pregnant adolescents and their partners and the influence of self-reported concurrency. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050108.292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Perneczky R, Tsolakidou A, Arnold A, Diehl-Schmid J, Grimmer T, Forstl H, Kurz A, Alexopoulos P. CSF soluble amyloid precursor proteins in the diagnosis of incipient Alzheimer disease. Neurology 2011; 77:35-8. [DOI: 10.1212/wnl.0b013e318221ad47] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Hemmer W, Jarisch R, Wieczorek D, Kapp A, Wedi B, Müller U, Schmid-Grendelmeier P, Hausmann O, Helbling A, Varga R, Stretz E, Rolle M, Przybilla B, Ruëff F, Krischan L, Schneider M, Sonnenschein U, Darsow U, Ring J, Eberlein B, Friedl TK, Garaganova J, Arnold A. Klinische In-vitro-Diagnostik. ALLERGO JOURNAL 2011. [DOI: 10.1007/bf03362489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Matei D, Shen C, Fang F, Schilder J, Li M, Arnold A, Zeng Y, Pilrose JM, Kulesavage C, Balch C, Berry W, Wulfridge P, Huang TH, Nephew KP. A phase II study of decitabine and carboplatin in recurrent platinum (Pt)-resistant ovarian cancer (OC). J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.5011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Kleine-Brueggeney M, Greif R, Ross S, Eichenberger U, Moriggl B, Arnold A, Luyet C. Ultrasound-guided percutaneous tracheal puncture: a computer-tomographic controlled study in cadavers. Br J Anaesth 2011; 106:738-42. [DOI: 10.1093/bja/aer026] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Bach S, Bombinski T, Daniels M, Gross D, Hogg T, Martin T, McMurray D, Naber E, Perez N, Schulman A, Tucker S, Andera‐Cato S, Arnold A, Blumberg A, Bord M, Feiertag A, Greaves M, Her A, Kennedy E, Orozco C, Rice C, Rodgers A, Sauer A, Schubert J, Tubbs C, Wray T, Vogt G, Shrestha L, Hillard C. Of Mice and MAGL (Monoacylglycerol Lipase). FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.lb158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Aliño M, Grau R, Fernández-Sánchez A, Arnold A, Barat J. Influence of brine concentration on swelling pressure of pork meat throughout salting. Meat Sci 2010; 86:600-6. [DOI: 10.1016/j.meatsci.2010.04.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2009] [Revised: 03/29/2010] [Accepted: 04/01/2010] [Indexed: 11/26/2022]
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