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Abstract
A 59 year old man who had undergone left total knee arthroplasty in 2008 presented with a 5 month history of left knee pain and persistent swelling. Workup for infection was negative and the patient was suspected to be suffering from particle disease and chronic synovitis. Imaging revealed an internally rotated tibial component. Intraoperative findings revealed extensive polyethylene wear with resultant metalon- metal articulation, soft tissue metallosis and a pseudotumor like mass at the posterolateral aspect of the popliteal fossa. This was extensively debrided and revision knee arthroplasty was performed. Suboptimal component alignment can lead to localized high loading, wear and metallosis, which in this case resulted in the formation of a pseudotumor.
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Affiliation(s)
- S Sivananthan
- Department of Orthopaedic Surgery, Stanford University School of Medicine, Redwood City, California
| | - R Pirapat
- Department of Orthopaedic Surgery, Stanford University School of Medicine, Redwood City, California
| | - S B Goodman
- Department of Orthopaedic Surgery, Stanford University School of Medicine, Redwood City, California
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2
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Naumova V, Pereverzyev SV, Sivananthan S. A meta-learning approach to the regularized learning-case study: blood glucose prediction. Neural Netw 2012; 33:181-93. [PMID: 22706092 DOI: 10.1016/j.neunet.2012.05.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Revised: 03/06/2012] [Accepted: 05/18/2012] [Indexed: 11/27/2022]
Abstract
In this paper we present a new scheme of a kernel-based regularization learning algorithm, in which the kernel and the regularization parameter are adaptively chosen on the base of previous experience with similar learning tasks. The construction of such a scheme is motivated by the problem of prediction of the blood glucose levels of diabetic patients. We describe how the proposed scheme can be used for this problem and report the results of the tests with real clinical data as well as comparing them with existing literature.
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Affiliation(s)
- V Naumova
- Johann Radon Institute for Computational and Applied Mathematics-RICAM, Austrian Academy of Sciences, A-4040 Linz, Austria.
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3
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Nnoaham KE, Sivananthan S, Hummelshoj L, Jenkinson C, Webster P, Kennedy SH, Zondervan KT, Vodolazkaia A, Fassbender A, Kyama CM, Bokor A, Clerinx P, Gevaert O, Schols D, Huskens D, Meuleman C, Peeraer K, Tomassetti C, De Moor B, D'Hooghe TM, Opoien HK, Fedorcsak P, Abyholm T, Tanbo TG, Tanbo TG, Kavallaris A, Hornemann A, Bohlmann M, Griesinger G, Chalvatzas N, Diedrich K, Benaglia L, Pasin R, Somigliana E, Vercellini P, Ragni G, Fedele L, Bergqvist A, Lundholm C, Malki N, Swahn ML, Sparen P, Melin A. Session 05: Endometriosis: Impact, Diagnosis and Surgery. Hum Reprod 2010. [DOI: 10.1093/humrep/de.25.s1.5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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4
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Nnoaham K, Sivananthan S, Hummelshoj L, Jenkinson C, Webster P, Kennedy S, Zondervan K. I240 Societal impact of endometriosis. Int J Gynaecol Obstet 2009. [DOI: 10.1016/s0020-7292(09)60240-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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5
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Zondervan K, Sivananthan S, Nnoaham K, Hummelshoj L, Jenkinson C, Webster P, Kennedy S. I370 Susceptibility and risk factors for developing endometriosis: A diagnostic aid. Int J Gynaecol Obstet 2009. [DOI: 10.1016/s0020-7292(09)60370-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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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6
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Gupta BC, Konar S, Grein CH, Sivananthan S. Structural evolution due to Zn and Te adsorption on As-exposed Si(211): density functional calculation. J Phys Condens Matter 2009; 21:375502. [PMID: 21832348 DOI: 10.1088/0953-8984/21/37/375502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Systematic theoretical investigations are carried out under the density functional formalism in an effort to understand the initial structural evolution due to the adsorption of ZnTe on As-exposed Si(211). Our calculations indicate that after the adsorption of Zn and Te on the As-exposed Si(211), the stable atomic structure qualitatively follows the ideal atomic structure of Si(211) with alteration of various bond lengths. Since the basic symmetry of the Si(211) is preserved after the adsorption of ZnTe, the deposition of ZnTe on the As terminated Si(211) prior to the deposition of CdTe and HgCdTe is useful for obtaining an ultimate quality layer of HgCdTe on Si(211). Some of our results are compared with the available experimental results, and they are found to agree with each other qualitatively.
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Affiliation(s)
- Bikash C Gupta
- Department of Physics, Visva-Bharati, Santiniketan 731235, India
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7
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May E, Herder JL, Kuiper JH, Roberts S, Sivananthan S, Richardson JB, Grünhagen T, Urban J, Douglas T, Warnke PH, Martinez IZ, Johansen O. Design of an Endoreactor for the Cultivation of a Joint-Like-Structure. J Med Device 2009. [DOI: 10.1115/1.3147270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
To avoid revision surgeries in artificial joint replacements and to allow young people to have a joint replacement, using biological joint replacement created by tissue engineering is a promising alternative. Several research groups have tissue engineered bone [Warnke 2004] and cartilage [Chung 2007] separately. The tissue engineering of a joint, consisting of bone and cartilage is the next frontier. The present study focuses on the design of a novel device, named Endoreactor, that is employing the mechanosensitivity of cells to create a joint-like-structure (JLS) consisting of a bone and cartilage sandwich, similar to an amphiarthrosis, by applying a mechanical loading regime to a stem cell seeded scaffold construct during endocultivation. This way, the patients who will eventually need the new joint will serve as their own bioreactor, having the joint grow in their own body. In the JLS, the outside layers are designed to become bone, using a 6 mm thick scaffold with high stiffness. The center layer is a 4 mm thick scaffold which is compliant so as to experience more strain than the outside scaffolds to stimulate cartilage formation. Compression is realized by placing the JLSs between the long links of a kite-shaped four-bar linkage. This Endoreactor is powered by natural body motion through connection to the musculoskeletal system of the host, which in the experimental phase is a Gottingen minipig. The loading frequency and rest versus active time is dictated by the activity level of the minipig. This results in a natural loading pattern that is employed for the stimulation of cartilage formation in the JLS. A tensile force created during ambulation is converted into compressive action between the two long links of the mechanism. A mechanical stop limits the motion. This way controlled intermittent dynamic compression between 2.5% and 12.5% is realized in the cartilage layer of the JLS. All functions are integrated into a single piece compliant mechanism which is produced out of titanium using 3D rapid prototyping by selective laser melting technology. The mechanism can be fitted with cages that hold the scaffolds for bone and cartilage in place and protect them from external loads while being implanted. A safety spring was added to accommodate for large actuation excursions. A number of prototypes were produced and tested for fatigue, plastic deformation, failure load, and displacements of the long links at the JLS locations under different axial loads. These tests confirmed the proper mechanical functioning of the Endoreactor. Work with animal models making use of the device to culture an amphiarthosis-like joint is foreseen in the near future. This work was carried out at part of MYJOINT: Living Bioreactor—Growing a New Joint in a Human Back, EU FP6-2004-NEST-C-1, Proposal No. 028861.
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Affiliation(s)
- E. May
- Delft University of Technology, The Netherlands
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Ramadurai D, Norton E, Hale J, Garland JW, Stephenson LD, Stroscio MA, Sivananthan S, Kumar A. Fluorescent resonance energy transfer based detection of biological contaminants through hybrid quantum dot-quencher interactions. IET Nanobiotechnol 2008; 2:47. [PMID: 18500912 DOI: 10.1049/iet-nbt:20070033] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A nanoscale sensor employing fluorescent resonance energy transfer interactions between fluorescent quantum dots (QDs) and organic quencher molecules can be used for the multiplexed detection of biological antigens in solution. Detection occurs when the antigens to be detected displace quencher-labelled inactivated (or dead) antigens of the same type attached to QD-antibody complexes through equilibrium reactions. This unquenches the QDs, allowing detection to take place through the observation of photoluminescence in solution or through the fluorescence imaging of unquenched QD complexes trapped on filter surfaces. Multiplexing can be accomplished by using several different sizes of QDs, with each size QD labelled with an antibody for a different antigen, providing the ability to detect several types of antigens or biological contaminants simultaneously in near real-time with high specificity and sensitivity.
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Affiliation(s)
- D Ramadurai
- EPIR Technologies Inc., Bolingbrook, IL 60440, USA.
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9
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De Silva WMM, Sivananthan S, De Silva D, Fernando N. Biliary tract injury during cholecystectomy: a retrospective descriptive review of clinical features, treatment and outcome. ACTA ACUST UNITED AC 2007; 51:132-6. [PMID: 17461322 DOI: 10.4038/cmj.v51i4.1141] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- W M M De Silva
- Department of Surgery, Faculty of Medical Sciences, University of Sri Jayawardenepura, Sri Lanka.
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10
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Warnke PH, Sherry E, Russo PAJ, Açil Y, Wiltfang J, Sivananthan S, Sprengel M, Roldàn JC, Schubert S, Bredee JP, Springer ING. Antibacterial essential oils in malodorous cancer patients: clinical observations in 30 patients. Phytomedicine 2006; 13:463-7. [PMID: 16785038 DOI: 10.1016/j.phymed.2005.09.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2005] [Accepted: 07/07/2005] [Indexed: 05/10/2023]
Abstract
Malodorous necrotic ulcers in cancer patients are of major concern as it leads to social isolation and poor quality of life. Current medications and topical therapies have proven inadequate in their ability to reduce foul smell to acceptable levels. We report the positive experience we have had in using antibacterial essential oils in patients with incurable head and neck cancer and associated malodorous necrotic ulcers. All patients received a standard course of therapy with oral or systemic antibiosis. In addition, we rinsed the ulcers with an antibacterial essential oil mix (mainly based on Eucalyptus oil) twice a day. All patients experienced complete resolution of the foul smell by only the third or fourth day of therapy. As a secondary effect we saw that besides smell reduction the oils had anti-inflammatory effects on neoplastic ulcers. In some patients ulcers started to heal and achieved complete re-epithiliazation. The patients experienced great personal relief upon resolution of their malodorous conditions. Quality of life improved significantly with the resulting reintroduction of social contact with friends and relatives.
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Affiliation(s)
- P H Warnke
- Department of Oral and Maxillofacial Surgery, University of Kiel, Germany.
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Arif M, Sivananthan S, Choon DSK. Revision of total hip arthroplasty using an anterior cortical window, extensive strut allografts, and an impaction graft: follow-up study. J Orthop Surg (Hong Kong) 2004; 12:25-30. [PMID: 15237118 DOI: 10.1177/230949900401200106] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To report the outcome of revised total hip arthroplasty procedures involving an anterior cortical window, extensive strut allografts, and an Exeter impaction graft. METHOD Eight patients (9 hips) with a mean age of 58 years underwent revision of total hip arthroplasty using the Exeter hip impaction graft system and strut allografts between 1995 and 1998. An extensile anterior approach was used, and an anterior cortical window was created in the femur, to remove the old implant. External strut allografts were attached by wires to provide cortical support. The mean follow-up duration was 74 months. Indications for surgery were aseptic loosening of previous implants in 8 hips and infection of one hip that had previously undergone total arthroplasty. RESULTS 19 Dall Miles cables, 4 ordinary cerclage wires, and 8 cerclage wires tightened with the clincher knot technique were used to secure the allograft to the host bone. The strut grafts were found to be incorporated in all cases. No wires became loose. One patient developed 20 degrees of angulation at the allograft-host bone junction. Using the method of Fowler and Gie, we found that one femoral implant had subsided 2 mm within the cement mantle. Two other implants had 1 mm of subsidence at the cement bone interface, and one patient had a major subsidence of 15 mm that required revision. CONCLUSION Using an anterior cortical window in the femur to remove the old implant does not predispose to failure of the allograft to incorporate into the host bone.
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Affiliation(s)
- M Arif
- Department of Orthopaedic Surgery, University Malaya Medical Centre, Lembah Pantai, 59100 Kuala Lumpur, Malaysia
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12
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Hussien M, Sivananthan S, Anderson N, Shiels A, Tracey N, Odling-Smee GW. Primary leiomyosarcoma of the breast: diagnosis, management and outcome. A report of a new case and review of literature. Breast 2004; 10:530-4. [PMID: 14965634 DOI: 10.1054/brst.2000.0276] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2000] [Accepted: 11/21/2000] [Indexed: 11/18/2022] Open
Abstract
Primary leiomyosarcoma of the breast is very rare and represents a diagnostic challenge. Only 16 cases have been reported in the English language literature. We report another new case and have analysed reports of the previous cases aiming to present a simple evidence-based approach to the clinical, radiological and pathological diagnosis of this rare tumour. The average age of presentation is 56 years. All neoplasms have been limited to the breast at the time of diagnosis. The usual presentation is a slowly growing mass, but in the current case report the patient present with mastalgia. There is always a possibility of local recurrence or distant spread, which can occur many years after primary surgery. Leiomyosarcoma must be histologically distinguished from leiomyoma and the presence of >3 mitoses per 10 high-power fields is usually indicative of malignancy. Immunohistochemistry is helpful to confirm diagnosis. As this is a slow-growing malignant tumour with a propensity for local recurrence, total mastectomy is the treatment of choice. The tumour is not hormone-dependent and hormone manipulation is not a treatment option.
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Affiliation(s)
- M Hussien
- The Breast Surgery Unit, Belfast City Hospital, Lisburn Road, Belfast BT9 7AB, UK
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13
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Abstract
PURPOSE To evaluate the clinical and radiological outcome in patients undergoing small stem Exeter total hip replacement. METHODS A total of 46 small stem Exeter total hip replacements were performed on 44 consecutive patients (18 men and 26 women) attending the University of Malaya Medical Centre. The mean age at the time of operation was 58 years (range, 24-81 years). Of the 46 procedures performed, 35 were primary total hip replacements and 11 were revision operations, with aseptic loosening of the original implant being the main indication for revision. The main indications for surgery in primary cases were avascular necrosis and rheumatoid arthritis. Clinical and radiographic outcomes were assessed at 6 weeks', 12 weeks', 6 months' follow-up, and annually thereafter. Postoperative cementing technique was also assessed. RESULTS The mean follow-up period was 4 years. The mean Oxford Hip Score improved from 46 points preoperatively to 17 points at the final follow-up examination. There were no revision operations, no implant breakages, and no excessive migration of the implants. The potential complications of implant failure due to smaller implant size and increased patient activity were not observed. CONCLUSION Due to the smaller size of Asian femora, the small stem Exeter implant is a very useful development. This study suggests that it will perform as well as its larger counterparts.
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Affiliation(s)
- S Sivananthan
- Department of Orthopaedic Surgery, University Malaya Medical Centre, Lembah Pantai 59100, Kuala Lumpur, Malaysia.
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Abstract
We report the synthesis and biological evaluation of a series of new tricyclic analogs of the hormone melatonin, which act as probes of the constraints at the hormone's receptor site with regard to the lower N1-C2 region of the indole moiety of melatonin. Three of the new compounds, N-[2-(2-methoxy-6,7,8,9-tetrahydropyrido[1,2-a]indol-10-yl)ethyl]acetamide (9), and the respective propionamide 10 and butyramide 11, are as potent as melatonin in the Xenopus laevis melanophore model.
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Affiliation(s)
- A Tsotinis
- School of Pharmacy, Department of Pharmaceutical Chemistry, University of Athens, Greece.
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Ashokan R, Sivananthan S, Velicu S. Mercury cadmium telluride : A superior choice for near room temperature infrared detectors (Review Paper). DEFENCE SCI J 2001. [DOI: 10.14429/dsj.51.2206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Abstract
The removal of broken implanted intramedullary nails secondary to re-fracture or non-union is challenging. In 12 cases a simple and safe method has been used to remove broken implants.
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Affiliation(s)
- K S Sivananthan
- Department of Orthopaedic Surgery, Hospital Fatimah, Ipoh, Malaysia
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Wootton R, Loane M, Mair F, Moutray M, Harrisson S, Sivananthan S, Allen A, Doolittle G, McLernan A. The potential for telemedicine in home nursing. J Telemed Telecare 1999; 4:214-8. [PMID: 10505357 DOI: 10.1258/1357633981932262] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [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: 11/18/2022]
Abstract
We assessed the proportion of home nursing visits that could be replaced by home telenursing in the UK. A retrospective review of nursing notes in the UK was undertaken using an abstraction instrument developed and tested in the US. A total of 1951 episodes of patient care at home were reviewed: 1450 from Liverpool and 501 from Belfast. A total of 1626 (83%) of the episodes involved 'hands-on' interventions. In Belfast two observers estimated that 14% of home nursing visits could be done via telemedicine while in Liverpool two more observers gave an estimate of 16%. Inter-rater agreement was high (kappa = 0.93 for the Belfast observers and 0.79 for the Liverpool observers). Pilot trials of an analogue video-phone in Belfast suggested that even relatively low-quality compressed video might be useful for home nursing. These findings suggest that telemedicine may have a significant role in the delivery of home health care in the UK.
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Affiliation(s)
- R Wootton
- Institute of Telemedicine and Telecare, Queen's University, Belfast, UK.
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Wang L, Sivananthan S, Sporken R, Caudano R. Interface properties and valence-band discontinuity of MnS/ZnSe heterostructures. Phys Rev B Condens Matter 1996; 54:2718-2722. [PMID: 9986122 DOI: 10.1103/physrevb.54.2718] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Sporken R, Sivananthan S, Reno J, Faurie JP. X-ray photoemission from small mercury clusters on II-VI semiconductor surfaces. Phys Rev B Condens Matter 1988; 38:1351-1356. [PMID: 9946397 DOI: 10.1103/physrevb.38.1351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Hefetz Y, Lee D, Nurmikko AV, Sivananthan S, Chu X, Faurie PJ. Quasi-two-dimensional excitons in a strongly localized regime in CdTe-ZnTe superlattices. Phys Rev B Condens Matter 1986; 34:4423-4425. [PMID: 9940230 DOI: 10.1103/physrevb.34.4423] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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