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Madhani F, Maniar RA, Burfat A, Ahmed M, Farooq S, Sabir A, Domki AK, Page-Shipp L, Khowaja S, Safdar N, Khan AJ, Khan PY. Automated chest radiography and mass systematic screening for tuberculosis. Int J Tuberc Lung Dis 2021; 24:665-673. [PMID: 32718398 DOI: 10.5588/ijtld.19.0501] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND: Systematic screening for TB using automated chest radiography (ACR) with computer-aided detection software (CAD4TB) has been implemented at scale in Karachi, Pakistan. Despite evidence supporting the use of ACR as a pre-screen prior to Xpert® MTB/RIF diagnostic testing in presumptive TB patients, there has been no data published on its use in mass screening in real-world settings.METHOD: Screening was undertaken using mobile digital X-ray vehicles at hospital facilities and community camps. Chest X-rays were offered to individuals aged ≥15 years, regardless of symptoms. Those with a CAD4TB score of ≥70 were offered Xpert testing. The association between Xpert positivity and CAD4TB scores was examined using data collected between 1 January and 30 June 2018 using a custom-built data collection tool.RESULTS: Of the 127 062 individuals screened, 97.2% had a valid CAD4TB score; 11 184 (9.1%) individuals had a CAD4TB score ≥70. Prevalence of Xpert positivity rose from 0.7% in the <50 category to 23.5% in the >90 category. The strong linear association between CAD4TB score and Xpert positivity was found in both community and hospital settings.CONCLUSION: The strong association between CAD4TB scores and Xpert positivity provide evidence that an ACR-based pre-screening performs well when implemented at scale in a high-burden setting.
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Affiliation(s)
- F Madhani
- Global Health Directorate, Indus Health Network, Karachi, Pakistan
| | - R A Maniar
- Global Health Directorate, Indus Health Network, Karachi, Pakistan
| | - A Burfat
- Global Health Directorate, Indus Health Network, Karachi, Pakistan
| | - M Ahmed
- Global Health Directorate, Indus Health Network, Karachi, Pakistan
| | - S Farooq
- Global Health Directorate, Indus Health Network, Karachi, Pakistan
| | - A Sabir
- Global Health Directorate, Indus Health Network, Karachi, Pakistan
| | - A K Domki
- Provincial TB Control Program, Department of Health, Government of Sindh, Hyderabad, Pakistan
| | | | - S Khowaja
- Global Health Directorate, Indus Health Network, Karachi, Pakistan, Interactive Research and Development, Singapore
| | - N Safdar
- Global Health Directorate, Indus Health Network, Karachi, Pakistan
| | - A J Khan
- Global Health Directorate, Indus Health Network, Karachi, Pakistan, Interactive Research and Development, Singapore
| | - P Y Khan
- Interactive Research and Development, Singapore, Department of Clinical Research, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Idress H, Zaidi SZJ, Sabir A, Shafiq M, Khan RU, Harito C, Hassan S, Walsh FC. Cellulose acetate based Complexation-NF membranes for the removal of Pb(II) from waste water. Sci Rep 2021; 11:1806. [PMID: 33469047 PMCID: PMC7815919 DOI: 10.1038/s41598-020-80384-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 12/02/2020] [Indexed: 01/21/2023] Open
Abstract
This study investigates the removal of Pb(II) using polymer matrix membranes, cellulose acetate/vinyl triethoxysilane modified graphene oxide and gum Arabic (GuA) membranes. These complexation-NF membranes were successfully synthesized via dissolution casting method for better transport phenomenon. The varied concentrations of GuA were induced in the polymer matrix membrane. The prepared membranes M-GuA2–M-GuA10 were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscope and bio-fouling studies. Thermal stability of the membranes was determined by thermogravimetric analysis under nitrogen atmosphere. Dead end nanofiltration was carried out to study the perm- selectivity of all the membranes under varied pressure and concentration of Pb(NO3)2. The complexation-NF membrane performances were significantly improved after the addition of GuA in the polymer matrix membrane system. M-GuA8 membrane showed optimum result of permeation flux 8.6 l m−2 h−1. Rejection of Pb(II) ions was observed to be around 97.6% at pH 9 for all the membranes due to electrostatic interaction between CA and Gum Arabic. Moreover, with the passage of time, the rate of adsorption was also increased up to 15.7 mg g−1 until steady state was attained. Gum Arabic modified CA membranes can open up new possibilities in enhancing the permeability, hydrophilicity and anti-fouling properties.
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Affiliation(s)
- H Idress
- Department of Polymer Engineering and Technology, University of the Punjab, Lahore, 54590, Pakistan.
| | - S Z J Zaidi
- Institute of Chemical Engineering and Technology, University of the Punjab, Lahore, Pakistan.
| | - A Sabir
- Department of Polymer Engineering and Technology, University of the Punjab, Lahore, 54590, Pakistan
| | - M Shafiq
- Department of Polymer Engineering and Technology, University of the Punjab, Lahore, 54590, Pakistan
| | - R U Khan
- Department of Polymer Engineering and Technology, University of the Punjab, Lahore, 54590, Pakistan
| | - C Harito
- Industrial Engineering Department, Faculty of Engineering, Bina Nusantara University, Jakarta, 11480, Indonesia
| | - S Hassan
- Mechanical Engineering, Faculty of Engineering and Physical Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
| | - F C Walsh
- Electrochemical Engineering Laboratory, Faculty of Engineering and Environment, Engineering Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
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Jennath HS, Adarsh S, Chandran NV, Ananthan R, Sabir A, Asharaf S. Parkchain: A Blockchain Powered Parking Solution for Smart Cities. Front Blockchain 2019. [DOI: 10.3389/fbloc.2019.00006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Shalabh K, Ajai S, Vineet K, Sabir A. Are Gap and Cast Indices Predictors of Efficacy of Reduction in Fractures of Both Bones of the Leg? A Cohort Study. Malays Orthop J 2018; 12:15-19. [PMID: 30112123 PMCID: PMC6092537 DOI: 10.5704/moj.1807.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Introduction: Non-operative management has successfully been practised for long in diaphyseal fractures of both bones of the leg. This study attempts to establish an acceptability criteria for plaster cast in order to predict future loss of reduction and its adequacy. Materials and Methods: A total of forty subjects were included as per inclusion-exclusion criteria. Gap and cast indices were calculated in the immediate post reduction phase and at third week follow-up visit. Results: The mean values of gap and cast indices in the immediate post-reduction phase were 0.35±0.220 and 0.99±0.08 respectively and at the third week follow-up the mean value for both the parameters in those without loss of reduction were 1.11±0.50 and 1.03±0.09 respectively and in those with loss of reduction were 0.84±0.44 and 1.01±0.06 respectively. Conclusion: Gap and cast indices are not informative in assessing adequacy of reduction in diaphyseal fractures of both bones of the leg.
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Affiliation(s)
- K Shalabh
- Department of Orthopaedics, King George's Medical University, Lucknow, India
| | - S Ajai
- Department of Orthopaedics, King George's Medical University, Lucknow, India
| | - K Vineet
- Department of Orthopaedics, King George's Medical University, Lucknow, India
| | - A Sabir
- Department of Orthopaedics, King George's Medical University, Lucknow, India
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Ekoru K, Murphy GAV, Young EH, Delisle H, Jerome CS, Assah F, Longo–Mbenza B, Nzambi JPD, On'Kin JBK, Buntix F, Muyer MC, Christensen DL, Wesseh CS, Sabir A, Okafor C, Gezawa ID, Puepet F, Enang O, Raimi T, Ohwovoriole E, Oladapo OO, Bovet P, Mollentze W, Unwin N, Gray WK, Walker R, Agoudavi K, Siziya S, Chifamba J, Njelekela M, Fourie CM, Kruger S, Schutte AE, Walsh C, Gareta D, Kamali A, Seeley J, Norris SA, Crowther NJ, Pillay D, Kaleebu P, Motala AA, Sandhu MS. Deriving an optimal threshold of waist circumference for detecting cardiometabolic risk in sub-Saharan Africa. Int J Obes (Lond) 2017; 42:ijo2017240. [PMID: 29087388 PMCID: PMC5880575 DOI: 10.1038/ijo.2017.240] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 08/12/2017] [Accepted: 09/04/2017] [Indexed: 02/02/2023]
Abstract
BACKGROUND Waist circumference (WC) thresholds derived from western populations continue to be used in sub-Saharan Africa (SSA) despite increasing evidence of ethnic variation in the association between adiposity and cardiometabolic disease and availability of data from African populations. We aimed to derive a SSA-specific optimal WC cut-point for identifying individuals at increased cardiometabolic risk. METHODS We used individual level cross-sectional data on 24 181 participants aged ⩾15 years from 17 studies conducted between 1990 and 2014 in eight countries in SSA. Receiver operating characteristic curves were used to derive optimal WC cut-points for detecting the presence of at least two components of metabolic syndrome (MS), excluding WC. RESULTS The optimal WC cut-point was 81.2 cm (95% CI 78.5-83.8 cm) and 81.0 cm (95% CI 79.2-82.8 cm) for men and women, respectively, with comparable accuracy in men and women. Sensitivity was higher in women (64%, 95% CI 63-65) than in men (53%, 95% CI 51-55), and increased with the prevalence of obesity. Having WC above the derived cut-point was associated with a twofold probability of having at least two components of MS (age-adjusted odds ratio 2.6, 95% CI 2.4-2.9, for men and 2.2, 95% CI 2.0-2.3, for women). CONCLUSION The optimal WC cut-point for identifying men at increased cardiometabolic risk is lower (⩾81.2 cm) than current guidelines (⩾94.0 cm) recommend, and similar to that in women in SSA. Prospective studies are needed to confirm these cut-points based on cardiometabolic outcomes.International Journal of Obesity advance online publication, 31 October 2017; doi:10.1038/ijo.2017.240.
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Affiliation(s)
- K Ekoru
- Sandhu Group, Department of Medicine, University of Cambridge, Cambridge, UK
- Global Health and Populations Group, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - G A V Murphy
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - E H Young
- Sandhu Group, Department of Medicine, University of Cambridge, Cambridge, UK
- Global Health and Populations Group, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | - H Delisle
- Department of Nutrition, Faculty of Medicine, University of Montreal, Montreal, Canada
| | - C S Jerome
- Regional Institute of Public Health, University of Abomey-Calavi, Cotonou, Benin
| | - F Assah
- Department of Public Health, Faculty of Medicine and Biomedical Sciences, University of Yaounde I, Yaounde, Cameroon
| | - B Longo–Mbenza
- Faculty of Health Sciences, Walter Sisulu University, Eastern Cape, South Africa
| | - J P D Nzambi
- Department of Basic Sciences, Unit of Clinical Pharmacology and Pharmacovigilance, Faculty of Medicine, University of Kinshasa, Kinshasa, DR Congo
| | - J B K On'Kin
- Department of Internal Medicine, Faculty of Medicine, University of Kinshasa, Kinshasa, DR Congo
| | - F Buntix
- Department of General Practice, KU Leuven, Leuven, Belgium
| | - M C Muyer
- Department of Public Health, University of Kinshasa, Kinshasa, DR Congo
| | - D L Christensen
- Department of Public Health, University of Copenhagen, Copenhagen, Denmark
| | - C S Wesseh
- Ministry of Health and Social Welfare, Monrovia, Liberia
| | - A Sabir
- Department of Medicine, Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria
| | - C Okafor
- Department of Medicine & Physiology, Faculty of Medical Sciences, University of Nigeria, Enugu Campus/University of Nigeria Teaching Hospital, Ituku Ozalla, Enugu, Nigeria
| | - I D Gezawa
- Department of Medicine, College of Health Sciences, Bayero University Kano/Aminu Kano Teaching Hospital, Kano State, Kano, Nigeria
| | - F Puepet
- Department of Medicine, College of Medical Sciences, University of Jos, Jos, Nigeria
| | - O Enang
- Department of Internal Medicine, University of Calabar/University of Calabar Teaching Hospital, Calabar, Nigeria
| | - T Raimi
- Department of Medicine, Ekiti State University, Ado-Ekiti, Nigeria
| | - E Ohwovoriole
- Department of Medicine, College of Medicine, University of Lagos, Lagos, Nigeria
| | - O O Oladapo
- Division of Cardiovascular Medicine, Department of Medicine (University College Hospital), College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - P Bovet
- Institute of Social and Preventive Medicine, University of Lausanne, Lausanne, Switzerland
| | - W Mollentze
- University of the Free State, Bloemfontein, Republic of South Africa
| | - N Unwin
- MRC Epidemiology Unit, University of Cambridge, Cambridge, UK
| | - W K Gray
- Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, North Shields, Tyne and Wear, UK
| | - R Walker
- Northumbria Healthcare NHS Foundation Trust, North Tyneside General Hospital, North Shields, Tyne and Wear, UK
- Institute of Health and Society, Newcastle University, Newcastle, UK
| | - K Agoudavi
- National NCD Program, Ministry Of Health, Lome, Togo
| | - S Siziya
- School of Medicine, The Copperbelt University, Ndola, Zambia
| | - J Chifamba
- Physiology Department, University of Zimbabwe, College of Health Sciences, Harare, Zimbabwe
| | - M Njelekela
- Department of Physiology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - C M Fourie
- HART (Hypertension in Africa Research Team), North-West University, Potchefstroom, South Africa
| | - S Kruger
- Africa Unit for Transdisciplinary Health Research (AUTHeR), North-West University, Potchefstroom, South Africa
- MRC Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - A E Schutte
- HART (Hypertension in Africa Research Team), North-West University, Potchefstroom, South Africa
- MRC Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa
| | - C Walsh
- Department of Nutrition and Dietetics, University of the Free State, Bloemfontein, South Africa
| | - D Gareta
- Wellcome Trust Africa Centre for Health and Population Studies, University of KwaZulu-Natal, KwaZulu-Natal, South Africa
| | - A Kamali
- MRC/UVRI Uganda Research Unit on AIDS, Entebbe, Uganda
| | - J Seeley
- MRC/UVRI Uganda Research Unit on AIDS, Entebbe, Uganda
| | - S A Norris
- MRC/Wits Developmental Pathways for Health Research Unit (DPHRU), University of the Witwatersrand, Johannesburg, South Africa
| | - N J Crowther
- Department of Chemical Pathology, National Health Laboratory Service, University of the Witwatersrand Medical School, Johannesburg, South Africa
| | - D Pillay
- Wellcome Trust Africa Centre for Health and Population Studies, University of KwaZulu-Natal, KwaZulu-Natal, South Africa
| | - P Kaleebu
- MRC/UVRI Uganda Research Unit on AIDS, Entebbe, Uganda
| | - A A Motala
- Department of Diabetes and Endocrinology, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - M S Sandhu
- Sandhu Group, Department of Medicine, University of Cambridge, Cambridge, UK
- Global Health and Populations Group, Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
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Shafiq M, Sabir A, Islam A, Khan S, Hussain S, Z. Butt M, Jamil T. Development and performance characteristics of silane crosslinked poly(vinyl alcohol)/chitosan membranes for reverse osmosis. J IND ENG CHEM 2017. [DOI: 10.1016/j.jiec.2016.12.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sabir A. Xenia and metaxenia in grapes: differences in berry and seed characteristics of maternal grape cv. 'Narince' (Vitis vinifera L.) as influenced by different pollen sources. Plant Biol (Stuttg) 2015; 17:567-573. [PMID: 25251333 DOI: 10.1111/plb.12266] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 09/05/2014] [Indexed: 06/03/2023]
Abstract
Literature investigations indicate that the grapes have quite complex fertilisation biology. This complexity necessitates extensive investigations to obtain reliable knowledge for both well-organised hybridisation studies and maximising grape yield. Therefore, this study was conducted to investigate the influences of self-, free- and cross-pollination on berry and seed characteristics in grape. Five different pollination treatments were applied to 'Narince', the most widely known and popular white wine grape in Turkey. Pollen tests indicated that all the cultivars had satisfactory in vitro pollen viability percentages. Free-pollination produced a significantly higher percentage berry set. Among the pollinizers, the use of pollen of 'Thompson Seedless' and 'Cardinal' varieties resulted in higher berry set percentage in 'Narince'. The free-pollination was also superior in giving the highest weight, length and width of the berry, as well as number of seeds per berry. These findings revealed that there were strong xenial and metaxenial effects in the studied grape cultivars. Among the pollinizer cultivars, the most effective pollinator was 'Thompson Seedless'. Hence, for better berry set and quality, the use of 'Thompson Seedless' as a pollinizer may be an attractive option in both grape production and breeding studies.
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Affiliation(s)
- A Sabir
- Department of Horticulture, Faculty of Agriculture, University of Selcuk, Konya, Turkey
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Mohammed IA, Schneider J, Schiffer R, Hussein J, Hailu T, Eshete M, Abate F, Sabir A, Habte D. CALCINOSIS CUTIS - A SERIES OF 59 CONSECUTIVE CASES CONFINED AMONG WOMEN. East Afr Med J 2013; 90:142-146. [PMID: 26866099] [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] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
BACKGROUND Calcinosis cutis is the cutaneous deposition of calcium salts. Tumoral Calcinosis is a condition consisting of massive subcutaneous deposits of calcium salts often overlying large joints in otherwise healthy patients. OBJECTIVE To describe the characteristics of a series of patients with Tumoral Calcinosis in the Gurage Zone of Central Ethiopia. METHODOLOGY Data was collected from 59 patients who presented with clinical diagnosis of calcinosis cutis around hip region between January 2005 and January 2009. RESULTS All cases were females, with a mean (standard deviation) age at diagnosis of 50.7(10.8). The duration of illness ranged from one to eighteen years. The cases were distributed in the different villages of Gurage Zone without any sign of clustering of cases. The lesions were localized around hip region on both sides. The patients did not have any related co-morbidity or any history of similar illness among close family members. None of the patients gave history of evident trauma to the site of the lesions. Significant proportion of the patients (53.4%) confirmed to carry water container and/or other goods on their side. Serum Phosphate and Calcium levels in selected patients were with in normal limit. Histo-pathological examinations of five cases revealed Calcium deposits in collagenous connective tissue. CONCLUSION The lesion was found to be relatively common in the study area and specifically confined to females. The probable factor associated with the cases is carrying objects on their side (hip area). Further research with in-depth clinical and laboratory evaluation is of paramount importance.
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Affiliation(s)
- I A Mohammed
- Department of Pathology, Faculty of Medicine, Addis Ababa University, P. O. Box 9086, Addis Ababa, Ethiopia.
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Liu Z, Ahmed M, Sabir A, Humphries S, Goldberg SN. Computer modeling of the effect of perfusion on heating patterns in radiofrequency tumor ablation. Int J Hyperthermia 2007; 23:49-58. [PMID: 17575723 DOI: 10.1080/02656730601094415] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE To use an established computer simulation model of radiofrequency (RF) ablation to further characterize the effect of varied perfusion on RF heating for commonly used RF durations and electrode types, and different tumor sizes. METHODS Computer simulation of RF heating using 2-D and 3-D finite element analysis (Etherm) was performed. Simulated RF application was systematically modeled on clinically relevant application parameters for a range of inner tumor perfusion (0-5 kg/m3-s) and outer normal surrounding tissue perfusion (0-5 kg/m3-s) for internally cooled 3-cm single and 2.5-cm cluster electrodes over a range of tumor diameters (2-5 cm), and RF application times (5-60 min; n = 4618 simulations). Tissue heating patterns and the time required to heat the entire tumor +/- a 5-mm margin to > 50 degrees C were assessed. Three-dimensional surface response contours were generated, and linear and higher order curve-fitting was performed. RESULTS For both electrodes, increasing overall tissue perfusion exponentially decreased the overall distance of the 50 degrees C isotherm (R2 = 0.94). Simultaneously, increasing overall perfusion exponentially decreased the time required to achieve thermal equilibrium (R2 = 0.94). Furthermore, the relative effect of inner and outer perfusion varied with increasing tumor size. For smaller tumors (2 cm diameter, 3-cm single; 2-3 cm diameter, cluster), the ability and time to achieve tumor ablation was largely determined by the outer tissue perfusion value. However, for larger tumors (4-5 cm diameter single; 5 cm diameter cluster), inner tumor perfusion had the predominant effect. CONCLUSION Computer modeling demonstrates that perfusion reduces both RF coagulation and the time to achieve thermal equilibrium. These results further show the importance of considering not only tumor perfusion, but also size (in addition to background tissue perfusion) when attempting to predict the effect of perfusion on RF heating and ablation times.
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Affiliation(s)
- Z Liu
- Department of Radiology, Beth Israel Deaconess Medical Center-Harvard Medical School, Boston, MA 02215, USA
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Embarch K, Bounakhla M, Bajja A, Ibnmajah M, Jacimovic R, Smodis B, Byrne AR, Sabir A. Instrumental neutron activation analysis of Moroccan geological samples using the k0-standardization method. J Radioanal Nucl Chem 2004. [DOI: 10.1023/b:jrnc.0000030933.94875.7e] [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: 11/12/2022]
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Abstract
A tablet formulation when compressed using market image tooling may cause picking of powder. A D-optimal statistical experiment was designed to optimize the direct compression formulation and the process to alleviate picking of powder. The effects of levels of magnesium stearate, colloidal silicon dioxide (CSD), and lubrication time on picking were investigated using original compression tooling. These optimization results provided a small robust manufacturing region, hence a change in the cut angles of embossed letters and numbers from 70 degrees to 90 degrees in the modified compression tooling was evaluated. A statistical analysis of the data identified a robust manufacturing region that included formulations containing magnesium stearate 1-1.25% w/w, CSD 0.1-0.3% w/w, with a lubrication time of 5-10 min when compressed using modified compression tooling. The results indicate a significant reduction in picking by increasing the cut angles of embossed letters and numbers in the modified compression tooling. By evaluating interactions between various variables, we demonstrate a concentration dependent effect of CSD on the lubrication efficiency of magnesium stearate and compactability of microcrystalline cellulose containing formulation. In addition, the lubrication efficiency of magnesium stearate is maintained by blending CSD with powder blend prior to lubrication with magnesium stearate.
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Affiliation(s)
- A Sabir
- Pharmaceutical Sciences, GlaxoWellcome Inc., Research Triangle Park, Durham, NC 27709, USA
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Abstract
The aim of this study is to evaluate the albedo effect on the neutron transmission probability through slab shields. For this reason we have considered an infinite homogeneous slab having a fixed thickness equal to 20 lambda (lambda is the mean free path of the neutron in the slab). This slab is characterized by the factor Ps (scattering probability) and contains a vacuum channel which is formed by two horizontal parts and an inclined one (David, M. C. (1962) Duc and Voids in shields. In Reactor Handbook, Vol. III, Part B, p. 166). The thickness of the vacuum channel is taken equal to 2 lambda. An infinite plane source of neutrons is placed on the first of the slab (left face) and detectors, having windows equal to 2 lambda, are placed on the second face of the slab (right face). Neutron histories are sampled by the Monte Carlo method (Booth, T. E. and Hendricks, J. S. (1994) Nuclear Technology 5) using exponential biasing in order to increase the Monte Carlo calculation efficiency (Levitt, L. B. (1968) Nuclear Science and Engineering 31, 500-504; Jehouani, A., Ghassoun, J. and Abouker, A. (1994) In Proceedings of the 6th International Symposium on Radiation Physics, Rabat, Morocco) and we have applied the statistical weight method which supposes that the neutron is born at the source with a unit statistical weight and after each collision this weight is corrected. For different values of the scattering probability and for different slopes of the inclined part of the channel we have calculated the neutron transmission probability for different positions of the detectors versus the albedo at the vacuum channel-medium interface. Some analytical representations are also presented for these transmission probabilities.
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Affiliation(s)
- A Khanouchi
- Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, University Cadi Ayyad, Marrakech, Morocco
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Khanouchi A, Sabir A, Boulkheir M, Ichaoui R, Ghassoun J, Jehouani A. The neutron channeling phenomenon. Appl Radiat Isot 1997; 48:1673-6. [PMID: 9463884 DOI: 10.1016/s0969-8043(97)00173-5] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Shields, used for protection against radiation, are often pierced with vacuum channels for passing cables and other instruments for measurements. The neutron transmission through these shields is an unavoidable phenomenon. In this work we study and discuss the effect of channels on neutron transmission through shields. We consider an infinite homogeneous slab, with a fixed thickness (20 lambda, with lambda the mean free path of the neutron in the slab), which contains a vacuum channel. This slab is irradiated with an infinite source of neutrons on the left side and on the other side (right side) many detectors with windows equal to 2 lambda are placed in order to evaluate the neutron transmission probabilities (Khanouchi, A., Aboubekr, A., Ghassoun, J. and Jehouani, A. (1994) Rencontre Nationale des Jeunes Chercheurs en Physique. Casa Blanca Maroc; Khanouchi, A., Sabir, A., Ghassoun, J. and Jehouani, A. (1995) Premier Congré International des Intéractions Rayonnements Matière. Eljadida Maroc). The neutron history within the slab is simulated by the Monte Carlo method (Booth, T. E. and Hendricks, J. S. (1994) Nuclear Technology 5) and using the exponential biasing technique in order to improve the Monte Carlo calculation (Levitt, L. B. (1968) Nuclear Science and Engineering 31, 500-504; Jehouani, A., Ghassoun, J. and Aboubker, A. (1994) In Proceedings of the 6th International Symposium on Radiation Physics, Rabat, Morocco). Then different geometries of the vacuum channel have been studied. For each geometry we have determined the detector response and calculated the neutron transmission probability for different detector positions. This neutron transmission probability presents a peak for the detectors placed in front of the vacuum channel. This study allowed us to clearly identify the neutron channeling phenomenon. One application of our study is to detect vacuum defects in materials.
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Affiliation(s)
- A Khanouchi
- Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, University Cadi Ayyad, Marrakech, Morocco
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Khanouchi A, Sabir A, Boulkheir M, Ichaoui R, Ghassoun J, Jehouani A. The vacuum geometry effect on neutron transmission and spatial resolution of neutron transmission. Appl Radiat Isot 1997; 48:1663-6. [PMID: 9463882 DOI: 10.1016/s0969-8043(97)00171-1] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Frequently, shields used against radiation contain some vacuum channels. We have therefore considered an infinite slab with a fixed thickness (thickness 20 lambda with lambda the mean free path of the neutron in the slab) and an infinite plane source of neutrons which arrived on the left side of the slab; transmitted neutrons through the slab to its right side are detected by finite detectors having windows equal to 2 lambda. This slab contains a vacuum channel. This channel has many legs with several horizontal parts. We used the Monte Carlo method for sampling the neutron history in the slab with a spatial biasing technique in order to accelerate the calculation convergence (Levitt, L. B. (1968) Nuclear Science and Engineering 31, 500-504; Jehouani, A., Ghassoun, J. and Aboubker, A. (1994) In Proceedings of 6th International Symposium on Radiation Physics, Rabat, Morocco). We studied the effects of the angle position and the number of horizontal parts of the channel on the neutron transmission. We have studied the effect of the vacuum channel opening (Artigas, R. and Hungerford, H. E. (1969) Nuclear Science and Engineering 36, 295-303) on the neutron transmission; for several values of this opening we have calculated the neutron transmission probability for each detector position. This study allowed us to determine the optimal conditions of vacuum geometries to improve protection against neutrons. In the second part we considered a shield which consists of a slab and a two-legged vacuum channel with two horizontal parts. The spatial distribution of neutrons transmitted through the protection screen was determined. This distribution shows two peaks. The study was made for different distances between the two horizontal parts. We have determined the smallest distance between the two horizontal parts for which the two peaks can be resolved.
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Affiliation(s)
- A Khanouchi
- Nuclear Physics and Techniques Laboratory, Faculty of Sciences Semlalia, University Cadi Ayyad, Marrakech, Morocco
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Sabir A, Labraimi M, El Maghraoui M, Abbe J. Neutron activation analysis of Atlantic Moroccan marine sediments. Appl Radiat Isot 1995. [DOI: 10.1016/0969-8043(95)00111-5] [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: 10/27/2022]
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Sabir A, Newbury HJ, Todd G, Catty J, Ford-Lloyd BV. Determination of genetic stability using isozymes and RFLPs in beet plants regenerated in vitro. Theor Appl Genet 1992; 84:113-117. [PMID: 24203036 DOI: 10.1007/bf00223989] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/1991] [Accepted: 10/17/1991] [Indexed: 06/02/2023]
Abstract
Sugar, fodder and garden beet (Beta vulgaris L.) plants have been regenerated in culture from a range of expiant material. Of the regenerants 764 were subjected to isozyme analysis using eight enzyme-specific stains, and 60 were subjected to RFLP analysis using three cDNA probes. Both molecular techniques allowed the identification of somaclonal variant plants. Assessment of the numbers of variant isozymes and restriction fragments has allowed the calculation of the approximate percentage of variant alleles occurring in any one somaclonal regenerant, namely between 0.05% and 0.1%.
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Affiliation(s)
- A Sabir
- School of Biological Sciences, University of Birmingham, P.O. Box 363, B15 2TT, Birmingham, UK
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Farese RV, Bidot-López P, Sabir A, Smith JS, Schinbeckler B, Larson R. Parathyroid hormone acutely increases polyphosphoinositides of the rabbit kidney cortex by a cycloheximide-sensitive process. J Clin Invest 1980; 65:1523-6. [PMID: 6251113 PMCID: PMC371492 DOI: 10.1172/jci109818] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Parathyroid hormone(PTH) rapidly increases the concentrations of diphosphoinositide and triphosphoinositide in rabbit kidney cortex. Cycloheximide pretreatment abolishes these effects of PTH. These findings are similar to those reported for adrenocorticotropin and cyclic AMP action in the adrenal cortex, and suggest a common mechanism. Cycloheximide-sensitive effects of PTH, e.g., phosphaturia, may require polyphosphoinositides and/or other phospholipids.
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