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Wikström, Johan
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Publications (10 of 72) Show all publications
Hellström, J., Romanos Zapata, R., Libard, S., Wikström, J., Ortiz-Nieto, F., Alafuzoff, I. & Raininko, R. (2019). Evaluation of the INTERPRET decision-support system: can it improve the diagnostic value of magnetic resonance spectroscopy of the brain?. Neuroradiology, 61(1), 43-53
Open this publication in new window or tab >>Evaluation of the INTERPRET decision-support system: can it improve the diagnostic value of magnetic resonance spectroscopy of the brain?
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2019 (English)In: Neuroradiology, ISSN 0028-3940, E-ISSN 1432-1920, Vol. 61, no 1, p. 43-53Article in journal (Refereed) Published
Abstract [en]

Purpose: We evaluated in a clinical setting the INTERPRET decision-support system (DSS), a software generated to aid in MRS analysis to achieve a specific diagnosis for brain lesions.

Methods: The material consisted of 100 examinations of focal intracranial lesions with confirmed diagnoses. MRS was obtained at 1.5 T using TE 20–30 ms. Data were processed with the LCModel for conventional analysis. The INTERPRET DSS 3.1. was used to obtain specific diagnoses. MRI and MRS were reviewed by one interpreter. DSS analysis was made by another interpreter, in 80 cases by two interpreters. The diagnoses were compared with the definitive diagnoses. For comparisons between DSS, conventional MRS analysis, and MRI, the diagnoses were categorised: high-grade tumour, low-grade tumour, non-neoplastic lesion.

Results: Interobserver agreement in choosing the diagnosis from the INTERPRET database was 75%. The diagnosis was correct in 38/100 cases, incorrect in 57 cases. No good match was found in 5/100 cases. The diagnostic category was correct with DSS/conventional MRS/MRI in 67/58/52 cases, indeterminate in 5/8/20 cases, incorrect in 28/34/28 cases. Results with DSS were not significantly better than with conventional MRS analysis. All definitive diagnoses did not exist in the INTERPRET database. In the 61 adult patients with the diagnosis included in the database, DSS/conventional MRS/MRI yielded a correct diagnosis category in 48/32/29 cases (DSS vs conventional MRS: p = 0.002, DSS vs MRI: p = 0.0004).

Conclusion: Use of the INTERPRET DSS did not improve MRS categorisation of the lesions in the unselected clinical cases. In adult patients with lesions existing in the INTERPRET database, DSS improved the results, which indicates the potential of this software with an extended database.

Keywords
Brain, Computer-aided diagnosis, Decision-support system, Magnetic resonance imaging, Magnetic resonance spectroscopy
National Category
Radiology, Nuclear Medicine and Medical Imaging Clinical Laboratory Medicine
Research subject
Pathology
Identifiers
urn:nbn:se:uu:diva-366791 (URN)10.1007/s00234-018-2129-7 (DOI)000456076500010 ()30443796 (PubMedID)
Available from: 2018-11-24 Created: 2018-11-24 Last updated: 2019-03-29Bibliographically approved
Nelander, M., Hannsberger, D., Sundström Poromaa, I., Bergman, L., Weis, J., Åkerud, H., . . . Wikström, A.-K. (2018). Assessment of cerebral perfusion and edema in preeclampsia with intravoxel incoherent motion MRI.. Acta Obstetricia et Gynecologica Scandinavica, 97(10), 1212-1218
Open this publication in new window or tab >>Assessment of cerebral perfusion and edema in preeclampsia with intravoxel incoherent motion MRI.
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2018 (English)In: Acta Obstetricia et Gynecologica Scandinavica, ISSN 0001-6349, E-ISSN 1600-0412, Vol. 97, no 10, p. 1212-1218Article in journal (Refereed) Published
Abstract [en]

INTRODUCTION: Cerebral complications are the main reasons for morbidity and mortality in preeclampsia and eclampsia. As yet, we do not know whether the pathophysiology entails hypo- or hyperperfusion of the brain, or how and when edema emerges, due to the difficulty of examining the cerebral circulation.

MATERIAL AND METHODS: We have used a non-invasive diffusion weighted-magnetic resonance imaging technique, intravoxel incoherent motion, to study cerebral perfusion on the capillary level and cerebral edema in women with preeclampsia (n = 30), normal pregnancy (n = 32), and non-pregnant women (n = 16). Estimates of cerebral blood volume, blood flow, and edema were measured in 5 different regions. These points were chosen to represent blood supply areas of both the carotid and vertebrobasilar arteries, and to include both white and gray matter.

RESULTS: Except for the caudate nucleus, we did not detect any differences in cerebral perfusion measures on a group level. In the caudate nucleus, we found lower cerebral blood volume and lower blood flow in preeclampsia than in either normal pregnancy (P = .01 and P = .03, respectively) or non-pregnant women (both P = .02). No differences in edema were detected between study groups.

CONCLUSION: The cerebral perfusion measures were comparable between the study groups, except for a portion of the basal ganglia where hypoperfusion was detected in preeclampsia but not in normal pregnancy or non-pregnant women.

Keywords
cerebral circulation, eclampsia, edema, intravoxel incoherent motion, magnetic resonance imaging, perfusion, preeclampsia
National Category
Obstetrics, Gynecology and Reproductive Medicine
Identifiers
urn:nbn:se:uu:diva-357423 (URN)10.1111/aogs.13383 (DOI)000444070900010 ()29786833 (PubMedID)
Funder
Swedish Research Council, 2014-3561
Available from: 2018-08-16 Created: 2018-08-16 Last updated: 2018-11-14Bibliographically approved
Christou, C., Wikström, J. & Strömbäck, K. (2018). Bifurcation of the intratemporal facial nerve: A rare anatomical anomaly. ACTA OTO-LARYNGOLOGICA CASE REPORTS, 3(1), 15-18
Open this publication in new window or tab >>Bifurcation of the intratemporal facial nerve: A rare anatomical anomaly
2018 (English)In: ACTA OTO-LARYNGOLOGICA CASE REPORTS, ISSN 2377-2484, Vol. 3, no 1, p. 15-18Article in journal (Refereed) Published
Abstract [en]

The anatomical position of the facial nerve is a critical factor in determining surgical candidacy in patients with congenital aural atresia (CAA). All patients with CAA must preoperatively be evaluated using a grading score based on information gained from a high resolution CT scan. In patients not suitable for surgical reconstruction, implantation of novel hearing implants is increasingly used for hearing rehabilitation. We, here, describe a bifurcation of the intratemporal part of the facial nerve in a 5-year old boy with CAA undergoing implantation with a bone conductive hearing device.

Place, publisher, year, edition, pages
Taylor & Francis Group, 2018
Keywords
Congenital aural atresia, facial nerve, anomaly
National Category
Otorhinolaryngology
Identifiers
urn:nbn:se:uu:diva-377989 (URN)10.1080/23772484.2018.1436405 (DOI)000458788800004 ()
Available from: 2019-03-04 Created: 2019-03-04 Last updated: 2019-03-04Bibliographically approved
Nelander, M., Wikström, A.-K., Weis, J., Bergman, L., Larsson, A., Sundström Poromaa, I. & Wikström, J. (2018). Cerebral osmolytes and plasma osmolality in pregnancy and preeclampsia: a proton magnetic resonance spectroscopy study. American Journal of Hypertension, 31(7), 847-853
Open this publication in new window or tab >>Cerebral osmolytes and plasma osmolality in pregnancy and preeclampsia: a proton magnetic resonance spectroscopy study
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2018 (English)In: American Journal of Hypertension, ISSN 0895-7061, E-ISSN 1941-7225, Vol. 31, no 7, p. 847-853Article in journal (Refereed) Published
Abstract [en]

Background: Cerebral complications contribute substantially to mortality in preeclampsia. Pregnancy calls for extensive maternal adaptations, some associated with increased propensity for seizures, but the pathophysiology behind the eclamptic seizures is not fully understood. Plasma osmolality and sodium levels are lowered in pregnancy. This could result in extrusion of cerebral organic osmolytes, including the excitatory neurotransmitter glutamate, but this remains to be determined. The hypothesis of this study was that cerebral levels of organic osmolytes are decreased during pregnancy, and that this decrease is even more pronounced in women with preeclampsia.

Method: We used proton magnetic resonance spectroscopy to compare levels of cerebral organic osmolytes, in women with preeclampsia (n=30), normal pregnancy (n=32) and non-pregnant controls (n=16). Cerebral levels organic osmolytes were further correlated to plasma osmolality, and plasma levels of glutamate and sodium.

Results: Compared to non-pregnant women, women with normal pregnancy and preeclampsia had lower levels of the cerebral osmolytes myo-inositol, choline and creatine (p=0.001 or less), and all these metabolites correlated with each other (p<0.05). Women with normal pregnancies and preeclampsia had similar levels of osmolytes, except for glutamate, which was significantly lower in preeclampsia. Cerebral and plasma glutamate levels were negatively correlated with each other (p<0.008), and cerebral myo-inositol, choline and creatine levels were all positively correlated with both plasma osmolality and sodium levels (p<0.05).

Conclusion: Our results indicate that pregnancy is associated with extrusion of cerebral organic osmolytes. This includes the excitatory neurotransmitter glutamate, which may be involved in the pathophysiology of seizures in preeclampsia.

Keywords
Preeclampsia, eclampsia, proton magnetic resonance spectroscopy, cerebral osmolytes, glutamate
National Category
Obstetrics, Gynecology and Reproductive Medicine
Research subject
Obstetrics and Gynaecology
Identifiers
urn:nbn:se:uu:diva-341642 (URN)10.1093/ajh/hpy019 (DOI)000435458800015 ()29415199 (PubMedID)
Funder
Swedish Research Council, 2014-3561
Available from: 2018-02-12 Created: 2018-02-12 Last updated: 2018-08-29Bibliographically approved
Jensson, D., Enghag, S., Bylund, N., Jonsson, L., Wikström, J., Grindlund, M. E., . . . Rodriguez-Lorenzo, A. (2018). Cranial Nerve Coactivation and Implication for Nerve Transfers to the Facial Nerve.. Plastic and reconstructive surgery (1963), 141(4), 582e-585e
Open this publication in new window or tab >>Cranial Nerve Coactivation and Implication for Nerve Transfers to the Facial Nerve.
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2018 (English)In: Plastic and reconstructive surgery (1963), ISSN 0032-1052, E-ISSN 1529-4242, Vol. 141, no 4, p. 582e-585eArticle in journal (Refereed) Published
Abstract [en]

In reanimation surgery, effortless smile can be achieved by a nonfacial donor nerve. The underlying mechanisms for this smile development, and which is the best nonfacial neurotizer, need further clarification. The aim of the present study was therefore to further explore the natural coactivation between facial mimic muscles and muscles innervated by the most common donor nerves used in smile reanimation. The study was conducted in 10 healthy adults. Correlation between voluntary facial muscle movements and simultaneous electromyographic activity in muscles innervated by the masseter, hypoglossal, and spinal accessory nerves was assessed. The association between voluntary movements in the latter muscles and simultaneous electromyographic activity in facial muscles was also studied. Smile coactivated the masseter and tongue muscles equally. During the seven mimic movements, the masseter muscle had fewer electromyographically measured coactivations compared with the tongue (two of seven versus five of seven). The trapezius muscle demonstrated no coactivation during mimic movements. Movements of the masseter, tongue, and trapezius muscles induced electromyographically recorded coactivation in the facial muscles. Bite resulted in the strongest coactivation of the zygomaticus major muscle. The authors demonstrated coactivation between voluntary smile and the masseter and tongue muscles. During voluntary bite, strong coactivation of the zygomaticus major muscle was noted. The narrower coactivation pattern in the masseter muscle may be advantageous for central relearning and the development of a spontaneous smile. The strong coactivation between the masseter muscle and the zygomaticus major indicates that the masseter nerve may be preferred in smile reanimation.

National Category
Surgery
Identifiers
urn:nbn:se:uu:diva-347468 (URN)10.1097/PRS.0000000000004235 (DOI)000428668900014 ()29595736 (PubMedID)
Available from: 2018-04-03 Created: 2018-04-03 Last updated: 2018-06-20Bibliographically approved
Engman, J., Sundström Poromaa, I., Moby, L., Wikström, J., Fredriksson, M. & Gingnell, M. (2018). Hormonal Cycle and Contraceptive Effects on Amygdala and Salience Resting-State Networks in Women with Previous Affective Side Effects on the Pill.. Neuropsychopharmacology, 43(3), 555-563
Open this publication in new window or tab >>Hormonal Cycle and Contraceptive Effects on Amygdala and Salience Resting-State Networks in Women with Previous Affective Side Effects on the Pill.
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2018 (English)In: Neuropsychopharmacology, ISSN 0893-133X, E-ISSN 1740-634X, Vol. 43, no 3, p. 555-563Article in journal (Refereed) Published
Abstract [en]

The mechanisms linking ovarian hormones to negative affect are poorly characterized, but important clues may come from the examination of the brain's intrinsic organization. Here, we studied the effects of both the menstrual cycle and oral contraceptives (OCs) on amygdala and salience network resting-state functional connectivity using a double-blind, randomized, and placebo-controlled design. Hormone levels, depressive symptoms, and resting-state functional connectivity were measured in 35 healthy women (24.9±4.2 years) who had previously experienced OC-related negative affect. All participants were examined in the follicular phase of a baseline cycle and in the third week of the subsequent cycle during treatment with either a combined OC (30 μg ethinyl estradiol/0.15 mg levonorgestrel) or placebo. The latter time point targeted the midluteal phase in placebo users and steady-state ethinyl estradiol and levonorgestrel concentrations in OC users. Amygdala and salience network connectivity generally increased with both higher endogenous and synthetic hormone levels, although amygdala-parietal cortical connectivity decreased in OC users. When in the luteal phase, the naturally cycling placebo users demonstrated higher connectivity in both networks compared with the women receiving OCs. Our results support a causal link between the exogenous administration of synthetic hormones and amygdala and salience network connectivity. Furthermore, they suggest a similar, potentially stronger, association between the natural hormonal variations across the menstrual cycle and intrinsic network connectivity.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:uu:diva-333689 (URN)10.1038/npp.2017.157 (DOI)000419961500011 ()28741624 (PubMedID)
Funder
Swedish Research Council, 2016-01439Forte, Swedish Research Council for Health, Working Life and Welfare, 2007-1955, 2007-2116
Available from: 2017-11-16 Created: 2017-11-16 Last updated: 2018-02-14Bibliographically approved
Dhara, A. K., Arids, E., Fahlström, M., Wikström, J., Larsson, E.-M. & Strand, R. (2018). Interactive segmentation of glioblastoma for post-surgical treatment follow-up. In: Proc. 24th International Conference on Pattern Recognition: . Paper presented at ICPR 2018, August 20–24, Beijing, China (pp. 1199-1204). IEEE
Open this publication in new window or tab >>Interactive segmentation of glioblastoma for post-surgical treatment follow-up
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2018 (English)In: Proc. 24th International Conference on Pattern Recognition, IEEE, 2018, p. 1199-1204Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
IEEE, 2018
National Category
Medical Image Processing
Research subject
Computerized Image Processing
Identifiers
urn:nbn:se:uu:diva-368290 (URN)10.1109/ICPR.2018.8545105 (DOI)000455146801036 ()978-1-5386-3788-3 (ISBN)
Conference
ICPR 2018, August 20–24, Beijing, China
Note

Best paper award

Available from: 2018-12-03 Created: 2018-12-03 Last updated: 2019-02-21Bibliographically approved
Abu Hamdeh, S., Marklund, N., Lewén, A., Howells, T., Raininko, R., Wikström, J. & Enblad, P. (2018). Intracranial pressure elevations in diffuse axonal injury: association with nonhemorrhagic MR lesions in central mesencephalic structures.. Journal of Neurosurgery, 1-8
Open this publication in new window or tab >>Intracranial pressure elevations in diffuse axonal injury: association with nonhemorrhagic MR lesions in central mesencephalic structures.
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2018 (English)In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, p. 1-8Article in journal (Refereed) Epub ahead of print
Abstract [en]

OBJECTIVE Increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in patients with DAI. METHODS Fifty-two patients with severe TBI (median age 24 years, range 9-61 years), who had undergone ICP monitoring and had DAI on MRI, as determined using T2*-weighted gradient echo, susceptibility-weighted imaging, and diffusion-weighted imaging (DWI) sequences, were enrolled. The proportion of good monitoring time (GMT) with ICP > 20 mm Hg during the first 120 hours postinjury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression. RESULTS All patients had episodes of ICP > 20 mm Hg. The mean proportion of GMT with ICP > 20 mm Hg was 5%, and 27% of the patients (14/52) spent more than 5% of GMT with ICP > 20 mm Hg. The Glasgow Coma Scale motor score at admission (p = 0.04) and lesions on DWI sequences in the substantia nigra and mesencephalic tegmentum (SN-T, p = 0.001) were associated with the proportion of GMT with ICP > 20 mm Hg. In multivariable linear regression, lesions on DWI sequences in SN-T (8% of GMT with ICP > 20 mm Hg, 95% CI 3%-13%, p = 0.004) and young age (-0.2% of GMT with ICP > 20 mm Hg, 95% CI -0.07% to -0.3%, p = 0.002) were associated with increased ICP. CONCLUSIONS Increased ICP occurs in approximately one-third of patients with severe TBI who have DAI. Age and lesions on DWI sequences in the central mesencephalon (i.e., SN-T) are associated with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in patients with DAI.

Keywords
ADC = apparent diffusion coefficient, CPP = cerebral perfusion pressure, DAI = diffuse axonal injury, DWI = diffusion-weighted imaging, EVD = external ventricular drain, GCS = Glasgow Coma Scale, GMT = good monitoring time, GOSE = Glasgow Outcome Scale–Extended, ICC = intraclass correlation coefficient, ICP = intracranial pressure, MAP = mean arterial blood pressure, MRI, NICU = neurointensive care unit, SN-T = substantia nigra and mesencephalic tegmentum, SWI = susceptibility-weighted imaging, T2*GRE = T2*-weighted gradient echo, TBI, TBI = traumatic brain injury, diffuse axonal injury, diffusion-weighted imaging, elevated ICP, intracranial pressure, trauma, traumatic brain injury
National Category
Neurology Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-362207 (URN)10.3171/2018.4.JNS18185 (DOI)30215559 (PubMedID)
Available from: 2018-10-02 Created: 2018-10-02 Last updated: 2018-11-28Bibliographically approved
Dhara, A. K., Ayyalasomayajula, K. R., Arvids, E., Fahlström, M., Wikström, J., Larsson, E.-M. & Strand, R. (2018). Segmentation of Post-operative Glioblastoma in MRI by U-Net with Patient-specific Interactive Refinement. In: Proceedings, Brain Lesion (BrainLes) workshop: . Paper presented at 21st INTERNATIONAL CONFERENCE ON MEDICAL IMAGE COMPUTING & COMPUTER ASSISTED INTERVENTION, September 16-20, 2018, Granada, Spain.
Open this publication in new window or tab >>Segmentation of Post-operative Glioblastoma in MRI by U-Net with Patient-specific Interactive Refinement
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2018 (English)In: Proceedings, Brain Lesion (BrainLes) workshop, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Accurate volumetric change estimation of glioblastoma is very important for post-surgical treatment follow-up. In this paper, an interactive segmentation method was developed and evaluated with the aim to guide volumetric estimation of glioblastoma. U-Net based fully convolutional network is used for initial segmentation of glioblastoma from post contrast MR images. The max flow algorithm is applied on the probability map of U-Net to update the initial segmentation and the result is displayed to the user for interactive refinement. Network update is performed based on the corrected contour by considering patient specific learning to deal with large context variations among dierent images. The proposed method is evaluated on a clinical MR image databas eof 15 glioblastoma patients with longitudinal scan data. The experimental results depict an improvement of segmentation performance due to patient specific fine-tuning. The proposed method is computationally fast and efficient as compared to state-of-the-art interactive segmentation tools. This tool could be useful for post-surgical treatment follow-upwith minimal user intervention.

National Category
Medical Image Processing
Identifiers
urn:nbn:se:uu:diva-366550 (URN)
Conference
21st INTERNATIONAL CONFERENCE ON MEDICAL IMAGE COMPUTING & COMPUTER ASSISTED INTERVENTION, September 16-20, 2018, Granada, Spain
Funder
Swedish Research Council, 2014-6199Vinnova, 2017-02447
Note

Extended versions of all accepted papers will be published as LCNS proceedings by Springer-Verlag. http://www.brainlesion-workshop.org/

Available from: 2018-11-21 Created: 2018-11-21 Last updated: 2019-03-14Bibliographically approved
Hellström, J., Romanos Zapata, R., Libard, S., Wikström, J., Ortiz-Nieto, F., Alafuzoff, I. & Raininko, R. (2018). The value of magnetic resonance spectroscopy as a supplement to MRI of the brain in a clinical setting. PLoS ONE, 13(11), Article ID e0207336.
Open this publication in new window or tab >>The value of magnetic resonance spectroscopy as a supplement to MRI of the brain in a clinical setting
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2018 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 11, article id e0207336Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: There are different opinions of the clinical value of MRS of the brain. In selected materials MRS has demonstrated good results for characterisation of both neoplastic and non-neoplastic lesions. The aim of this study was to evaluate the supplemental value of MR spectroscopy (MRS) in a clinical setting.

MATERIAL AND METHODS: MRI and MRS were re-evaluated in 208 cases with a clinically indicated MRS (cases with uncertain or insufficient information on MRI) and a confirmed diagnosis. Both single voxel spectroscopy (SVS) and chemical shift imaging (CSI) were performed in 105 cases, only SVS or CSI in 54 and 49 cases, respectively. Diagnoses were grouped into categories: non-neoplastic disease, low-grade tumour, and high-grade tumour. The clinical value of MRS was considered very beneficial if it provided the correct category or location when MRI did not, beneficial if it ruled out suspected diseases or was more specific than MRI, inconsequential if it provided the same level of information, or misleading if it provided less or incorrect information.

RESULTS: There were 70 non-neoplastic lesions, 43 low-grade tumours, and 95 high-grade tumours. For MRI, the category was correct in 130 cases (62%), indeterminate in 39 cases (19%), and incorrect in 39 cases (19%). Supplemented with MRS, 134 cases (64%) were correct, 23 cases (11%) indeterminate, and 51 (25%) incorrect. Additional information from MRS was beneficial or very beneficial in 31 cases (15%) and misleading in 36 cases (17%).

CONCLUSION: In most cases MRS did not add to the diagnostic value of MRI. In selected cases, MRS may be a valuable supplement to MRI.

National Category
Radiology, Nuclear Medicine and Medical Imaging Clinical Laboratory Medicine
Research subject
Pathology
Identifiers
urn:nbn:se:uu:diva-366792 (URN)10.1371/journal.pone.0207336 (DOI)000450254000069 ()30440005 (PubMedID)
Available from: 2018-11-24 Created: 2018-11-24 Last updated: 2019-03-29Bibliographically approved
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