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Rajan KP, Gopanna A, Theravalappil R, Abdelghani EAM, Thomas SP. Partial replacement of carbon black with graphene in natural rubber/butadiene rubber based tire compound: Investigation of critical properties. J Polym Res 2022. [DOI: 10.1007/s10965-021-02871-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Rajan KP, Gopanna A, Abdelghani EAM, Thomas SP. Halloysite nanotubes (HNT) as reinforcement for compatibilized blends of polypropylene (PP) and polylactic acid (PLA). J Polym Res 2021. [DOI: 10.1007/s10965-021-02738-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Swapna VP, Nambissan PMG, Thomas SP, Vayyaprontavida Kaliyathan A, Jose T, George SC, Thomas S, Stephen R. Free volume defects and transport properties of mechanically stable polyhedral oligomeric silsesquioxane embedded poly(vinyl alcohol)‐poly(ethylene oxide) blend membranes. POLYM INT 2019. [DOI: 10.1002/pi.5815] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | | | - Selvin P Thomas
- Chemical Engineering Technology Department, Yanbu Industrial College and Advanced Materials Laboratory, Yanbu Research CenterRoyal Commission Yanbu Colleges and Institutes (RCYCI) Yanbu Kingdom of Saudi Arabia
| | - Abitha Vayyaprontavida Kaliyathan
- School of Chemical Sciences and International and Inter University Centre for Nanoscience and Nanotechnology (IIUCNN)Mahatma Gandhi University Kottayam India
| | - Thomasukutty Jose
- Centre for Nano Science and Technology, Department of Basic SciencesAmal Jyothi College of Engineering Kanjirapally India
| | - Soney C George
- Centre for Nano Science and Technology, Department of Basic SciencesAmal Jyothi College of Engineering Kanjirapally India
| | - Sabu Thomas
- School of Chemical Sciences and International and Inter University Centre for Nanoscience and Nanotechnology (IIUCNN)Mahatma Gandhi University Kottayam India
| | - Ranimol Stephen
- Department of ChemistrySt Joseph's College (Autonomous) Calicut India
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Gopanna A, Mandapati RN, Thomas SP, Rajan K, Chavali M. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and wide-angle X-ray scattering (WAXS) of polypropylene (PP)/cyclic olefin copolymer (COC) blends for qualitative and quantitative analysis. Polym Bull (Berl) 2018. [DOI: 10.1007/s00289-018-2599-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Gopanna A, Thomas SP, Rajan KP, Rajan R, Rainosalo E, Zavašnik J, Chavali M. Investigation of mechanical, dynamic mechanical, rheological and morphological properties of blends based on polypropylene (PP) and cyclic olefin copolymer (COC). Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2018.09.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Affiliation(s)
- Selvin P. Thomas
- Advanced Materials Laboratory of Yanbu Research Center and Department of Chemical Engineering Technology; Royal Commission for Yanbu-Colleges and Institutes; Yanbu Industrial City Kingdom of Saudi Arabia
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Rajan R, Rainosalo E, Ramamoorthy SK, Thomas SP, Zavašnik J, Vuorinen J, Skrifvars M. Mechanical, thermal, and burning properties of viscose fabric composites: Influence of epoxy resin modification. J Appl Polym Sci 2018. [DOI: 10.1002/app.46673] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Rathish Rajan
- Research and Development; Centria University of Applied Sciences; Talonpojankatu 2, Kokkola 67100 Finland
- Department of Materials Science; Tampere University of Technology; P.O. Box589, Tampere 33101 Finland
| | - Egidija Rainosalo
- Research and Development; Centria University of Applied Sciences; Talonpojankatu 2, Kokkola 67100 Finland
| | | | - Selvin P. Thomas
- Chemical Engineering Technology Department, Yanbu Industrial College and Advanced Materials Laboratory; Yanbu Research Center, Royal Commission Yanbu-Colleges and Institutes (RCYCI); Yanbu Alsinaiah 41612 Kingdom of Saudi Arabia
| | - Janez Zavašnik
- Centre for Electron Microscopy and Microanalysis; Jožef Stefan Institute; Ljubljana 1000 Slovenia
| | - Jyrki Vuorinen
- Department of Materials Science; Tampere University of Technology; P.O. Box589, Tampere 33101 Finland
| | - Mikael Skrifvars
- Swedish Centre for Resource Recovery; University of Borås; Allégatan 1, Borås 501 90 Sweden
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Rajan R, Rainosalo E, Thomas SP, Ramamoorthy SK, Zavašnik J, Vuorinen J, Skrifvars M. Modification of epoxy resin by silane-coupling agent to improve tensile properties of viscose fabric composites. Polym Bull (Berl) 2017. [DOI: 10.1007/s00289-017-2022-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Thomas SP, Rahaman M, Hussein IA. Impact of aspect ratio and CNT loading on the dynamic mechanical and flammability properties of polyethylene nanocomposites. e-Polymers 2014. [DOI: 10.1515/epoly-2013-0019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractIn this study, the effects of aspect ratio and loading of multiwalled carbon nanotubes (MWCNTs) on the dynamic mechanical, thermal, and flammability properties of low-density polyethylene (LDPE)/MWCNT nanocomposites prepared by the melt blending technique were investigated. At low CNT loading, CNT with low aspect ratio acted as a plasticizer in LDPE. The storage modulus of the nanocomposites increased with the increase in aspect ratio and CNT loading. The increase in scan rate for the composites results in the decrease in total crystallinity, crystallization peak temperature, and a late onset of crystallization. The flammability properties like heat release capacity, peak heat release rate, and total heat release decrease with the increase in both aspect ratio and loading of CNTs in the composites.
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Affiliation(s)
| | - Mostafizur Rahaman
- 1Department of Chemical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia
| | - Ibnelwaleed A. Hussein
- 1Department of Chemical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia
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Thomas SP, Girei SA, Atieh MA, De S, Al-Juhani A. Rheological behavior of polypropylene nanocomposites at low concentration of surface modified carbon nanotubes. POLYM ENG SCI 2012. [DOI: 10.1002/pen.23143] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abdullateef AA, Thomas SP, Al‐Harthi MA, De SK, Bandyopadhyay S, Basfar A, Atieh MA. Natural rubber nanocomposites with functionalized carbon nanotubes: Mechanical, dynamic mechanical, and morphology studies. J Appl Polym Sci 2011. [DOI: 10.1002/app.35021] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Adedigba A. Abdullateef
- Department of Chemical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia
| | - Selvin P. Thomas
- Department of Chemical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia
| | - Mamdouh A. Al‐Harthi
- Department of Chemical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia
- Center of Research Excellence in Nanotechnology (CENT), King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia
| | - S. K. De
- Department of Chemical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia
| | - Sri Bandyopadhyay
- School of Materials Science and Engineering, University of New South Wales, Sydney 2052, Australia
| | - A.A. Basfar
- Atomic Energy Research Institute, King Abdulaziz City for Science and Technology, Riyadh 11442, Kingdom of Saudi Arabia
| | - Muataz A. Atieh
- Department of Chemical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia
- Center of Research Excellence in Nanotechnology (CENT), King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia
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Foster SF, Hunt GB, Thomas SP, Ross DL, Pearson MRB, Malik R. Tachycardia-induced cardiomyopathy in a young Boxer dog with supraventricular tachycardia due to an accessory pathway. Aust Vet J 2006; 84:326-31. [PMID: 16958630 DOI: 10.1111/j.1751-0813.2006.00030.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A 1-year-old male Boxer dog presented with sustained supraventricular tachycardia and tachycardia-induced cardiomyopathy. Conversion to sinus rhythm was achieved initially with intravenous lignocaine and subsequently with oral procainamide. Oral procainamide treatment was relatively successful in maintaining normal sinus rhythm with no side effects apart from a reversible change in coat colour. Electrophysiological studies demonstrated the presence of an accessory pathway connecting the right atrium to the right ventricle and confirmed the diagnosis of orthodromic atrioventricular reciprocating tachycardia. Radiofrequency catheter ablation of the accessory pathway led to permanent resolution of the supraventricular tachycardia and for 9.5 years the dog has had no further signs of cardiac disease. The successful treatment of this condition highlights the importance of differentiating tachycardia-induced cardiomyopathy from dilated cardiomyopathy.
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Affiliation(s)
- S F Foster
- University Veterinary Centre Sydney, The University of Sydney, NSW 2006, Australia
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Kizana E, Ginn SL, Smyth CM, Boyd A, Thomas SP, Allen DG, Ross DL, Alexander IE. Fibroblasts modulate cardiomyocyte excitability: implications for cardiac gene therapy. Gene Ther 2006; 13:1611-5. [PMID: 16838030 DOI: 10.1038/sj.gt.3302813] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In an earlier study exploring the potential of gene transfer to repair myocardial conduction defects, we observed that myotubes, generated by forced expression of MyoD, exhibit reduced excitability when also modified to express connexin43 (Cx43). We hypothesized that this effect was caused by gap junction-mediated coupling between myotubes and the underlying fibroblast feeder layer. This intriguing possibility has important implications for ongoing efforts to develop strategies for repairing myocardial conduction defects by gene transfer, and also provides novel insights into the electrophysiological function of naturally occurring heterologous cell coupling within the heart. Although a conductive function for fibroblasts through heterologous coupling has previously been reported, the current study provides novel evidence that fibroblasts can modulate cardiomyocyte excitability in a Cx43-dependent manner. In a co-culture study system, neonatal rat cardiomyocytes were grown on monolayers of mouse fibroblasts with genetically altered Cx43 expression and the effect on intrinsic beat frequency examined. Cardiomyocytes grown on wild-type (WT) fibroblasts expressing native levels of Cx43 beat significantly slower than cells grown on fibroblasts devoid of this molecule (germline knockout) or with dominant-negative functional suppression. Expression of Cx43 in fibroblasts from Cx43 knockout mice restored cardiomyocyte beat frequency, to rates comparable with those observed in co-culture with WT fibroblasts.
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Affiliation(s)
- E Kizana
- Department of Cardiology, Westmead Hospital, Westmead, New South Wales, Australia
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Thomas SP, Buckland JR, Rhys-Williams SR. Potential ototoxicity from triamcinolone, neomycin, gramicidin and nystatin (Tri-Adcortyl™) cream. J Laryngol Otol 2006; 119:48-50. [PMID: 15807966 DOI: 10.1258/0022215053222950] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Although rare, ototoxicity from the use of aminoglycoside drops is well recognized. Ototoxicity has not been described with the use of combination aminoglycoside-steroid-antifungal creams or ointments. We present the case of a 60-year-old man with a perforated tympanic membrane who suffered a total hearing loss after the instillation of cream containing triamcinolone, neomycin, gramicidin and nystatin (Tri-Adcortyl™ cream) into his ear canal. On balance, we believe that a number of potentially ototoxic constituents in this cream were responsible. Other possible causes of sensorineural hearing loss and the possible mechanisms of ototoxicity of this cream are discussed. The reasons why such creams may be particularly ototoxic, compared with drops, are also considered. The authors caution against the use of such creams or ointments in the ear if there is any suspicion of a tympanic membrane perforation.
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Affiliation(s)
- S P Thomas
- Department of Otolaryngology, Poole Hospital NHS Trust, Poole, Dorset BH15 2JB, UK.
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Abstract
BACKGROUND Transvenous catheter ablation for the treatment of atrial fibrillation is an evolving technique. AIM The purpose of this study was to identify subgroups of patients most likely to benefit from pulmonary vein electrical isolation. METHODS Patients with symptomatic atrial fibrillation resistant to pharmacological therapy were studied. Mapping-guided segmental application of radio-frequency energy was used to electrically isolate the pulmonary veins in 74 patients. Ischaemic or dilated cardiomyopathy was present in 34% of patients. Atrial fibrillation had been present for a mean time (+/- standard deviation) of 6.6 +/- 6.1 years. It was paroxysmal in 53 patients (72%). RESULTS The mean number of procedures was 1.6/patient. After 6 +/- 6 months, 73% of patients (54/74) were in sinus rhythm. Thirteen of those in sinus rhythm were using anti-arrhythmic medications (25%). Recurrence of atrial fibrillation soon after pulmonary vein isolation occurred in 50%. Patients with persistent/permanent atrial fibrillation were less likely to be in sinus rhythm at follow up (11/21 (52%) vs 43/53 (81%); P = 0.01). However, the rate of early recurrence was similar in the intermittent and the persistent/permanent groups (26/53 (49%) vs 11/21(52%), respectively; P-value not significant). Patients with persistent atrial fibrillation were more likely to experience a recurrence of atrial fibril-lation (89%; P = 0.04). No other baseline factors predicted procedural success. Cardiac tamponade occurred in two patients and moderate pulmonary vein stenosis (>50% diameter narrowing) occurred in three patients. CONCLUSIONS Pulmonary vein isolation is an effective curative treatment for a broad group of patients with atrial fibrillation. However, the procedure is only suitable for patients with problematic atrial fibrillation resistant to other therapies because of the small risk of serious complications.
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Affiliation(s)
- S P Thomas
- Department of Cardiology, Westmead Hospital and Westmead Private Hospital, Sydney, New South Wales, Australia.
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Thomas SP, Nicholson IA, Nunn GR, Ross DL. Radiofrequency lesions produced by handheld temperature controlled probes for use in atrial fibrillation surgery. Eur J Cardiothorac Surg 2001; 20:1188-93. [PMID: 11717026 DOI: 10.1016/s1010-7940(01)00986-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES Detailed analysis of the size and shape of lesions produced by handheld radiofrequency ablation devices at open heart surgery has not been reported previously. METHODS Radiofrequency lesions were made from the epicardial surface of the cardiac ventricles in open-chested dogs. The effects of electrode size, electrode temperature and duration of ablation were studied. In a second group of experiments simultaneous multielectrode ablation was performed on the ventricular epicardium after cold cardioplegia. RESULTS Using a single 12 x 2.5 mm electrode and a target temperature of 80 degrees C the lesion depth increased from 3.8+/-0.9 mm at 15 s, to 6.1+/-0.9 mm at 120 s (P=0.01). Increasing the target temperature from 70 to 90 degrees C (for 60 s) increased lesion depth from 5.0+/-1.2 to 5.6+/-1.7 mm (P=0.2). There was no difference in depth of lesions with the two electrode widths (4.0+/-0.5 mm (large) vs. 3.9+/-1.0 mm (small)). Lesions produced using the multielectrode probe (80 degrees C, 60 s) were 30-35 mm long with even penetration into the tissue. The mean depth of these lesions on microscopic sections was 3.9 mm. The mean width was 7.1 mm. CONCLUSIONS Handheld probes can be used to make deep linear lesions in the myocardium. Lesions expand rapidly and are wider than they are deep. A multielectrode ablation device allows rapid formation of linear lesions.
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Affiliation(s)
- S P Thomas
- Department of Cardiology, Westmead Hospital, Westmead, NSW 2145, Australia.
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Thomas SP. No, hatred is not what we need. Issues Ment Health Nurs 2001; 22:727-8. [PMID: 11881176 DOI: 10.1080/01612840152712983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Affiliation(s)
- S P Thomas
- College of Nursing, University of Tennessee, Knoxville, USA.
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Affiliation(s)
- S P Thomas
- Nursing, The University of Tennessee College of Nursing, Knoxville, USA
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Thomas SP, Guy DJ, Rees A, Collins L, Ross DL. Production of narrow but deep lesions suitable for ablation of atrial fibrillation using a saline-cooled narrow beam Nd:YAG laser catheter. Lasers Surg Med 2001; 28:375-80. [PMID: 11344520 DOI: 10.1002/lsm.1065] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVE Lines of radiofrequency ablation for cure of atrial fibrillation are broad, and the consequent loss of atrial mass may impair atrial function and contribute to the risk of stroke. We studied whether Nd:YAG laser could produce deep but narrower lesions. STUDY DESIGN/MATERIALS AND METHODS Laser lesions were made in ventricular myocardium of nonperfused ovine hearts and at thoracotomy in dogs. RESULTS Lesions were well demarcated, deep, and narrow. Saline irrigation prevented crater formation for energy levels below 200 J. Lesion depth increased with increasing duration of ablation (maximum 5.3 +/- 0.8mm, P < 0.01). The depth to width ratio was >1 in all cases (maximum 2.5 +/- 1.6). The narrowest lesions were made by using high power, short duration of exposure, and intermittent delivery. CONCLUSIONS Irrigated Nd:YAG laser can be used to make deep narrow myocardial lesions without crater formation. Laser ablation may be more suitable than radiofrequency ablation for intraoperative or catheter-based cure of atrial fibrillation.
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Affiliation(s)
- S P Thomas
- Department of Cardiology, Westmead Hospital, Westmead, New South Wales, Australia
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Abstract
TOPIC Teaching anger management in the community. PURPOSE To describe anger management and offer guidelines for assessing potential participants and teaching healthy behaviors. SOURCES Drawing from the literature, more than 10 years of quantitative and qualitative studies by our research team, and 5 years of experience in conducting anger management groups, the author presents basic principles of teaching anger management. A model is described for a 4-week group for women. CONCLUSIONS Anger management has wide applicability to a variety of constituencies for both primary and secondary prevention. Advanced practice psychiatric nurses are well-qualified to provide this psychoeducational intervention.
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Affiliation(s)
- S P Thomas
- College of Nursing, University of Tennessee, USA.
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Thomas SP. Dispelling myths about depression. Issues Ment Health Nurs 2001; 22:1-3. [PMID: 11885058 DOI: 10.1080/01612840116798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Thomas SP. Taking "Healthy People 2010" seriously. Issues Ment Health Nurs 2000; 21:721-2. [PMID: 11854978 DOI: 10.1080/016128400750044233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Abstract
The purposes of this article are to review literature on anger's link to cancer, to analyze the state of the science in this area, and to propose some directions for future research. Extremely low anger scores have been noted in numerous studies of patients with cancer. Such low scores suggest suppression, repression, or restraint of anger. There is evidence to show that suppressed anger can be a precursor to the development of cancer, and also a factor in its progression after diagnosis. Some studies indicate that it may be beneficial for patients to mobilize anger to battle their cancer. However, there is a paucity of research on the outcomes of various anger interventions. Longitudinal studies that repeatedly measure anger and other moods over the disease trajectory are needed.
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Affiliation(s)
- S P Thomas
- College of Nursing, University of Tennessee, Knoxville 37996-4180, USA
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Thomas SP. Restraints must be a last resort! Issues Ment Health Nurs 2000; 21:651-2. [PMID: 11855042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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Abstract
Researchers have seldom invited patients with chronic pain to describe their lived experiences. This phenomenologic study involved in-depth interviews with nine women and four men with nonmalignant chronic pain. The essence of participants' experiences was unremitting torment by a force or monster that cannot be tamed. The body was altered and recalcitrant, the life world was shrunken, and the pain set up a barrier that separated them from other people. Time seemed to stop; the future was unfathomable. Findings of this study contribute to the phenomenological literature that explores the human body and its symbolic meanings and call into question the idealized positive depiction of chronic illness that is prominent in contemporary literature.
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Affiliation(s)
- S P Thomas
- College of Nursing, University of Tennessee, Knoxville, USA
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Thomas SP, Bircher-Lehmann L, Thomas SA, Zhuang J, Saffitz JE, Kléber AG. Synthetic strands of neonatal mouse cardiac myocytes: structural and electrophysiological properties. Circ Res 2000; 87:467-73. [PMID: 10988238 DOI: 10.1161/01.res.87.6.467] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of the present study was to morphologically and electrically characterize synthetic strands of mouse ventricular myocytes. Linear strands of mouse ventricular myocytes with widths of 34.7+/-4.4 microm (W(1)), 57.9+/-2.5 microm (W(2)), and 86.4+/-3. 6 microm (W(3)) and a length of 10 mm were produced on glass coverslips with a photolithographic technique. Action potentials (APs) were measured from individual cells within the strands with cell-attached microelectrodes. Impulse propagation and AP upstrokes were measured with multisite optical mapping (RH237). Immunostaining was performed to assess cell-cell connections and myofibril arrangement with polyclonal antisera against connexin43 and N-cadherins and monoclonal antibodies against cardiac myosin. Light microscopy and myosin staining showed dense growth of well-developed elongated myocytes with lengths of 34.2+/-4.2 microm (W(1)), 36. 9+/-5.8 microm (W(2)), and 43.7+/-6.9 microm (W(3)), and length/width ratios of 3.9+/-0.2. Gap junctions were distributed around the cell borders (3 to 4 junctions/microm(2) cell area). Each cell was connected by gap junctions to 6.5+/-1.1 neighboring cells. AP duration shortened with time in culture (action potential duration at 50% repolarization: day 4, 103+/-34 ms; day 8, 16+/-3 ms; P:<0.01). Minimum diastolic potential and AP amplitude were 71+/-5 and 97.2+/-7.6 mV, respectively. Conduction velocity and the maximum dV/dt of the AP upstroke were 43.9+/-13.6 cm/s and 196+/-67 V/s, respectively. Thus, neonatal ventricular mouse myocytes can be grown in continuous synthetic strands. Gap junction distribution is similar to the neonatal pattern observed in the hearts of larger mammals. Conduction velocity is in the range observed in adult mice and in the higher range for mammalian species probably due to the higher dV/dt(max). This technique will permit the study of propagation, AP, and structure-function relations at cellular resolution in genetically modified mice.
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Affiliation(s)
- S P Thomas
- Department of Physiology, University of Bern, Switzerland
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Abstract
Arrests of American girls for assault and weapons charges are rapidly increasing, at rates exceeding those for boys. Yet research on girls' violence is scant. We surveyed a national sample of 213 girls (ages 9-19) via personal interview or an Internet questionnaire, regarding anger precipitants and behaviors, interpersonal relationships, and experiences of discipline at home and school. Girls were categorized as violent (n = 54) if they had been suspended or expelled from school for fighting or bringing a weapon, or charged with a violent offense by the juvenile justice system. The remaining girls (n = 159) were categorized as nonviolent. The anger of violent girls tended to be intense and generalized, while the anger of nonviolent girls was precipitated by specific situations of injustice. Correlates of feeling angry enough to hit or hurt someone were loneliness, unfair treatment by adults, not liked by classmates, and somatic anger symptoms. Violent girls were significantly more likely to dislike school and perceive school discipline as unfair. Both groups of girls held negative views of television violence and curfews. Although girls with well-established patterns of aggression need psychotherapy, school-based interventions such as emotional literacy and violence prevention programs may also be helpful. Mental health nurses are well prepared to serve in a consultative role to schools, assisting in the development and delivery of violence prevention programming.
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Affiliation(s)
- H Smith
- Southeastern Psychological Services, Knoxville, Tennessee, USA
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Thomas SP. Taking a fresh look at the national tragedy of suicide. Issues Ment Health Nurs 2000; 21:345-6. [PMID: 11249353 DOI: 10.1080/016128400247960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Abstract
The aim of this study was to determine the relationship between the size of discontinuities in lines of ablation and wavefront propagation. Discontinuities in linear radiofrequency lesions used for the treatment of atrial fibrillation may be proarrhythmic and a major clinical problem. A better understanding of the electrophysiological properties of these discontinuities (isthmuses) may assist in their detection and treatment. Linear lesions were made in the right atrial free wall using a Nd:YAG laser in 12 dogs. Conduction properties across the discontinuities were studied by pacing from either side of the lesion. Two of the three isthmuses less than 0.8 mm(2) in cross section (smallest 0.2 mm(2)) conducted at extrastimulus intervals of 300 ms. All three failed to conduct at cycle lengths close to the atrial effective refractory period. Isthmuses above 0.8 mm(2) (n¿=8) conducted at all cycle lengths. Conduction slowing (mean slowest conduction 0.5 +/- 0.3 m/s) occurred in the region of the isthmus but the overall delay was only 6 +/- 6 ms where propagation through the isthmus occurred. The effect on conduction of small discontinuities in linear lesions is dependent on the size of the residual isthmus. All but the very smallest of discontinuities in linear lesions conduct and therefore have the potential to participate in reentrant arrhythmias. Efforts should be directed toward the development of ablation techniques that reliably produce continuous transmural linear lesions for cure of atrial fibrillation and flutter.
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Affiliation(s)
- S P Thomas
- The Department of Cardiology, Westmead Hospital, Westmead, NSW 2145, Australia. thomas.pyl.unibe.ch
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Thomas SP. From the editor--psychotherapy in cyberspace? Issues Ment Health Nurs 2000; 21:239-40. [PMID: 11075064 DOI: 10.1080/016128400248059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Thomas SP. Telling our stories: what are nurses angry about? Revolution 2000; 8:56-63, 98-101. [PMID: 10711215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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Thomas SP, Nunn GR, Nicholson IA, Rees A, Daly MP, Chard RB, Ross DL. Mechanism, localization and cure of atrial arrhythmias occurring after a new intraoperative endocardial radiofrequency ablation procedure for atrial fibrillation. J Am Coll Cardiol 2000; 35:442-50. [PMID: 10676692 DOI: 10.1016/s0735-1097(99)00559-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVES The purpose of this study was to test a new pattern of radiofrequency ablation for atrial fibrillation (AFib) intended to optimize atrial activation, and to demonstrate the usefulness of catheter techniques for mapping and ablation of postoperative atrial arrhythmias. BACKGROUND Linear radiofrequency lesions have been used to cure AFib, but the optimal pattern of lesions is unknown and postoperative tachyarrhythmias are common. METHODS A radial pattern of linear radiofrequency lesions (Star) was made using an endocardial open surgical approach in 25 patients. Postoperative arrhythmias were induced and characterized during electrophysiological studies in 15 patients. RESULTS The AFib was abolished in most patients (91%), but atrial flutter (AFlut) occurred in 96% of patients postoperatively. At postoperative electrophysiological studies, 37 flutter morphologies were studied in 15 patients (46% spontaneous, cycle length [CL] 223 +/- 25 ms). Seven mechanisms (lesions discontinuity, n = 6; focal mechanism, n = 1) of AFlut were characterized in six patients. In these cases, flutter was abolished using further catheter radiofrequency ablation. In the remaining cases, flutter was usually localized to an area involving the interatrial septum, but no critical isthmus was identified for ablation. After 16 +/-10 months, 15 patients (65%) were asymptomatic with (n = 3) or without (n = 12) antiarrhythmic medications. Eight (35%) patients had persistent arrhythmias. Postoperative atrial electrical activation was near physiological. CONCLUSIONS The AFib maybe abolished using a radial pattern of linear endocardial radiofrequency lesions, but postoperative AFlut is common even when lesions are made under optimal conditions. Endocardial mapping techniques can be used to characterize the flutter mechanisms, thus enabling subsequent successful catheter ablation.
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Affiliation(s)
- S P Thomas
- Department of Cardiology, Westmead Hospital, NSW, Australia
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Thomas SP, Nicholson IA, Nunn GR, Rees A, Trieu L, Daly MP, Wallace EM, Ross DL. Effect of atrial radiofrequency ablation designed to cure atrial fibrillation on atrial mechanical function. J Cardiovasc Electrophysiol 2000; 11:77-82. [PMID: 10695466 DOI: 10.1111/j.1540-8167.2000.tb00740.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION The effects of linear radiofrequency lesions in the atria for cure of atrial fibrillation on atrial contraction have not previously been quantified. METHODS AND RESULTS Atrial function was measured before and 30 +/- 24 days after a biatrial ablation procedure designed to cure atrial fibrillation in eight dogs and after a sham procedure in three dogs. Atrial mechanical function was assessed using Doppler diastolic blood flow velocities, atrial systolic pressure wave amplitude, and assessment of atrial contribution to cardiac output estimated by comparison of AV sequential pacing to ventricular pacing at the same heart rate. The mitral Doppler A/E velocity ratio was 1.03 +/- 0.45 before and 0.72 +/- 0.43 after ablation (P = 0.048). The tricuspid A/E ratio was 0.88 +/- 0.17 before and 0.71 +/- 0.12 after ablation (P = 0.04). The estimated atrial contribution to cardiac output was 18% +/- 9% before and 5% +/- 4% after ablation (P < 0.01). The left atrial systolic pressure wave amplitude was 2.8 +/- 1.5 mmHg before and 1.7 +/- 1.0 mmHg after ablation (P = 0.1). These changes were not observed in control dogs. Lesions covered 25% +/- 6% of the atrial endocardial surface. CONCLUSION Multiple linear radiofrequency lesions in the atria designed to cure atrial fibrillation may impair atrial contractility. Reduced atrial function is partly due to loss of atrial myocardial mass, but regional delays in atrial activation and splinting of the atria by scarring also may contribute.
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Affiliation(s)
- S P Thomas
- Department of Cardiology, Westmead Hospital, New South Wales, Australia
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Abstract
Systemic infusion of methacholine has been used to facilitate induction of atrial fibrillation. However, the dose-response relationship, reproducibility and effect of anesthetic agents on induction are not well understood. The use of methacholine to facilitate electrical induction of sustained (>10 minutes duration) atrial fibrillation or flutter was examined. In 25 dogs induction of atrial arrhythmias was attempted using a series of ten 50 Hz trains of 10 seconds duration delivered via an endocardial catheter in the baseline anaesthetized state and subsequently in the presence of graded doses of intravenous methacholine (maximum 5 microg/kg/min). Studies were repeated in 13 dogs to assess reproducibility. Twelve dogs (48%) had inducible sustained atrial flutter or fibrillation lasting greater than 10 minutes in the baseline state. During infusion of methacholine the remaining 13 (52%) dogs also had inducible sustained atrial flutter or fibrillation (mean infusion rate 1.6 +/- 1.9 microg/kg/min). Induction of sustained atrial flutter or fibrillation was reproducible in all but one dog. The type of anesthetic did not significantly affect inducibility. Induction of prolonged atrial fibrillation or flutter is possible in the baseline anaesthetized state in approximately half of dogs using high frequency programmed electrical stimulation. The yield of inducible sustained atrial fibrillation or flutter with programmed stimulation during intravenous infusion of methacholine was increased to 100%. Induction of sustained atrial fibrillation or flutter was highly reproducible.
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Affiliation(s)
- S P Thomas
- The Department of Cardiology, Westmead Hospital, Westmead, Australia
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Abstract
The purpose of this existential-phenomenological study was to investigate the experience of life after stroke rehabilitation, to provide a holistic view for nurses and others in providing care. Analysis involved a part-to-whole dialectic; selected transcripts, including the bracketing interview, were analyzed in an interpretive research group. There were 14 participants, with a 2-year median length of time since stroke; participants exhibited various disabilities. The world of the stroke survivor is grounded in a life of loss and effort from which emerged interrelated themes: independence/dependence, in control/out of control, and connection/disconnection with others. A fundamental aspect of these themes is a sense of continuity that coexists with discontinuity in the experience of self. The findings have implications for how nurses interact with stroke survivors, for goal-setting, and for specific strategies that focus on meanings for clients.
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Affiliation(s)
- J A Secrest
- University of Tennessee at Chattanooga 37403-2598, USA.
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Abstract
PURPOSE To derive a deeper understanding of postpartum depression (PPD) and its impact on the family through the experiences of fathers whose spouses suffered from this disorder. DESIGN Phenomenology. METHODS Eight men were interviewed. Interviews were recorded on audio tape and transcribed verbatim. Thematic analysis conducted within an interdisciplinary phenomenological research group led to a description of the experiences and emotions involved. RESULTS Respondents in this study revealed a major disruption in their lives and in their relationship with their wives as a result of PPD. The men experienced fear, confusion, and much concern for their spouses, and felt unable to help them in overcoming PPD. The inability to "fix the problem" created frustration and anger. The majority of the respondents reported that they made many sacrifices to hold the relationship and the family together. Even though the PPD improved over time, fathers were left to face an uncertain future with a spouse who seemed to be very different from the person they had previously known. CLINICAL IMPLICATIONS Health care professionals need to design interventions that are more supportive of men, for men also suffer when their spouses experience PPD.
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Affiliation(s)
- M Meighan
- Carson-Newman College, Jefferson City, Tennessee, USA
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Thomas SP. Responses to my editorial on the journal review process. Issues Ment Health Nurs 1999; 20:177-9. [PMID: 10633638 DOI: 10.1080/016128499248592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Thomas SP, Clout R, Deery C, Mohan AS, Ross DL. Microwave ablation of myocardial tissue: the effect of element design, tissue coupling, blood flow, power, and duration of exposure on lesion size. J Cardiovasc Electrophysiol 1999; 10:72-8. [PMID: 9930912 DOI: 10.1111/j.1540-8167.1999.tb00644.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
INTRODUCTION The biophysical properties of microwave electromagnetic radiation suggest that it may be an alternative to radiofrequency (RF) energy for ablation of arrhythmias resistant to treatment using RF ablation. METHODS AND RESULTS The aim of this study was to characterize lesions produced using simple element designs in a blood superfused ovine tissue model to simulate endocardial ablation. The effect of tissue bath flow, duration of microwave exposure, and changes in forward power on lesion size were examined using a modified monopole element. Lesion size increased with increasing duration of exposure and increasing forward power (P < 0.05). Lesion depth was 0.7+/-0.7 mm after 30 seconds and 11.5+/-1.9 mm after 360 seconds. Lesion depths at 61, 71, and 80 W were 6.4+/-3.7, 8.9+/-2.0, and 11.9+/-1.2 mm, respectively. Altering flow within the bath from 3 to 5 L/min did not significantly change lesion size. CONCLUSION Simple element designs can be used to produce a range of lesions from very small sizes to lesions that are transmural in the ventricle. The temperature half-time for microwave ablation is far greater than that of RF ablation. Like RF lesions, the lesions produced by microwave ablation have greater width than depth. Deep penetration of lesions into the ventricular myocardium can only be achieved with these elements by producing lesions of perhaps unnecessarily large volume.
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Affiliation(s)
- S P Thomas
- Department of Cardiology, Westmead Hospital, New South Wales, Australia
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Abstract
In this existential-phenomenological investigation middle-class African American women (n = 9) in the Southern United States were interviewed about their experience of anger in daily life. The purpose of the study was to examine what African American women's anger is about, what it means, and how it is experienced. Transcribed interviews were analyzed using a hermeneutic process. The thematic structure of African American women's anger comprises three main elements that stand out as figural: power, control, and respect. These figural elements can be understood only when seen against the ground of a racist Southern culture that produces pervasive mistrust. These findings are of importance to clinicians, who cannot deliver culturally competent interventions to African American female clients without a clear understanding of the complexity and meaning of their anger experience.
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Affiliation(s)
- B Fields
- College of Nursing, University of Tennessee at Knoxville 37996-4180, USA
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Thomas SP. Is science a dangerous Golem? Issues Ment Health Nurs 1998; 19:95-6. [PMID: 9601306 DOI: 10.1080/016128498249097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Thomas SP. Assessing and intervening with anger disorders. Nurs Clin North Am 1998; 33:121-33. [PMID: 9478910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Nurses often find angry patients threatening. In this article, current research will be synthesized to provide guidance to nurses whose specialty area may not be psychiatric nursing. Guidelines for assessing and intervening with angry clients will be provided. Such guidelines are likely to be useful to nurses in every clinical setting, from the emergency room to the rural clinic to the high-tech hospital unit. Nurses will also learn some techniques for managing their own anger at uncooperative or hostile clients.
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Affiliation(s)
- S P Thomas
- University of Tennessee at Knoxville, College of Nursing, Knoxville, Tennessee, USA
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Thomas SP. Sisyphus, Proteus, and other characters in the odyssey of nursing science development. Issues Ment Health Nurs 1998; 19:3-8. [PMID: 9479098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Affiliation(s)
- A F Wood
- Carson-Newman College, Knoxville, Tennessee, USA
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