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1.
PLoS One ; 19(4): e0296357, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38578749

RESUMEN

OBJECTIVE: Quantitative values derived from PET brain images are of high interest for neuroscientific applications. Insufficient DT correction (DTC) can lead to a systematic bias of the output parameters obtained by a detailed analysis of the time activity curves (TACs). The DTC method currently used for the Siemens 3T MR BrainPET insert is global, i.e., differences in DT losses between detector blocks are not considered, leading to inaccurate DTC and, consequently, to inaccurate measurements masked by a bias. However, following careful evaluation with phantom measurements, a new block-pairwise DTC method has demonstrated a higher degree of accuracy compared to the global DTC method. APPROACH: Differences between the global and the block-pairwise DTC method were studied in this work by applying several radioactive tracers. We evaluated the impact on [11C]ABP688, O-(2-[18F]fluoroethyl)-L-tyrosine (FET), and [15O]H2O TACs. RESULTS: For [11C]ABP688, a relevant bias of between -0.0034 and -0.0053 ml/ (cm3 • min) was found in all studied brain regions for the volume of distribution (VT) when using the current global DTC method. For [18F]FET-PET, differences of up to 10% were observed in the tumor-to-brain ratio (TBRmax), these differences depend on the radial distance of the maximum from the PET isocenter. For [15O]H2O, differences between +4% and -7% were observed in the GM region. Average biases of -4.58%, -3.2%, and -1.2% for the regional cerebral blood flow (CBF (K1)), the rate constant k2, and the volume of distribution VT were observed, respectively. Conversely, in the white matter region, average biases of -4.9%, -7.0%, and 3.8% were observed for CBF (K1), k2, and VT, respectively. CONCLUSION: The bias introduced by the global DTC method leads to an overestimation in the studied quantitative parameters for all applications compared to the block-pairwise method. SIGNIFICANCE: The observed differences between the two DTC methods are particularly relevant for research applications in neuroscientific studies as they affect the accuracy of quantitative Brain PET images.


Asunto(s)
Encéfalo , Oximas , Tomografía de Emisión de Positrones , Piridinas , Tomografía de Emisión de Positrones/métodos , Encéfalo/diagnóstico por imagen , Encéfalo/irrigación sanguínea , Fantasmas de Imagen , Cabeza , Imagen por Resonancia Magnética
2.
Appl Radiat Isot ; 205: 111161, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38163386

RESUMEN

Due to increased demand, cyclotron has an expanding role in producing Gallium-68 (68Ga) radiopharmaceuticals using solid and liquid targets. Though the liquid target produces lower end-of-bombardment activity compared to the solid target, our study presents the performance of 68Ga radiopharmaceuticals production using the liquid target by evaluating the end-of-bombardment activity and the end-of-purification activity of [68Ga]GaCl3. We also present the effect of increasing irradiation time, which significantly improves the end-of-synthesis yield. From the result obtained, the end-of-bombardment activity produced was 4.48 GBq, and the [68Ga]GaCl3 end-of-purification activity produced was 2.51 GBq with below-limit metallic impurities. Increasing the irradiation time showed a significant increase in the end-of-synthesis activity from 1.33 GBq to 1.95 GBq for [68Ga]Ga-PSMA-11 and from 1.13 GBq to 1.74 GBq for [68Ga]Ga-DOTA-TATE. Based on the improvements made, the liquid target production of 68Ga radiopharmaceuticals is feasible and reproducible to accommodate up to 5 patients per production. In addition, this work also discusses the issues encountered, together with the possible corrective and preventative measures.


Asunto(s)
Radioisótopos de Galio , Radiofármacos , Humanos , Ciclotrones
3.
S Afr Med J ; 113(10): 37-41, 2023 10 23.
Artículo en Inglés | MEDLINE | ID: mdl-37881911

RESUMEN

BACKGROUND: Pregnant women were indirectly affected by the COVID-19 pandemic owing to heightened stress, fear of mother-to-child transmission of COVID-19 and the disruption of antenatal health services. Increased stress and lack of antenatal healthcare could result in an increase in adverse birth outcomes such as preterm birth or low birthweight. OBJECTIVES: Using a case-control design, to compare the prevalence of low birthweight among infants born before and during the pandemic in Soweto, South Africa. METHOD: Infants born before the pandemic and national lockdown were included in the control group, while infants who were in utero and born during the pandemic were included in the case group. Only infants born ≥37 weeks' gestation with no birth complications were included. Multivariable logistic regression was employed to determine whether the pandemic was associated with an increase in low birthweight. A birthweight <2.5 kg was classified as low birthweight. RESULTS: In total, 199 mother-infant pairs were included in the control group, with 201 mother-infant pairs in the case group. The prevalence of low birthweight was 4% in the control group and 11% in the case group, with those born during the pandemic at a higher risk of being of low birthweight. CONCLUSION: The high prevalence of low birthweight in infants born ≥37 weeks' gestation during the pandemic could result in an increase in child stunting and poor development. Future research should measure early child development and growth in infants born during the pandemic to assess whether there is a need to intervene and provide additional support to minimise the negative effects.


Asunto(s)
COVID-19 , Nacimiento Prematuro , Recién Nacido , Embarazo , Femenino , Humanos , Recien Nacido Prematuro , Nacimiento Prematuro/epidemiología , Resultado del Embarazo , Embarazo Múltiple , Peso al Nacer , Pandemias , Sudáfrica/epidemiología , COVID-19/epidemiología , Control de Enfermedades Transmisibles , Transmisión Vertical de Enfermedad Infecciosa
4.
Front Neurol ; 14: 1222260, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37905189

RESUMEN

Introduction: Recognizing the burden experienced by caregivers of stroke survivors, an intervention using mobile health applications (mHealth apps) has been proposed to support and empower stroke caregivers. This study aimed to assess the acceptability and expectations of healthcare providers, who play a vital role as gatekeepers in the healthcare system, to ensure the effectiveness and sustainability of the intervention. Methods: This was a concurrent mixed-method study design, with healthcare providers involved in stroke care management in the northeast regions of Malaysia as study participants. The qualitative component of the study was conducted using a phenomenological approach that involved in-depth interviews to explore the acceptability and expectations of healthcare providers regarding the adoption of mHealth apps in the context of stroke caregiving. The study was complemented by quantitative data collected through an online survey using an adjusted version of the technology acceptance model tool. Results: In total, 239 participants from diverse backgrounds and professions were enrolled in the study, with 12 in the qualitative component and 227 in the quantitative component. The findings from the quantitative survey showed that over 80% of the participants expressed their intention to use mHealth apps. The qualitative component generated two themes related to the acceptability and expectations of mHealth apps, which were integrated with the quantitative findings. Additionally, in-depth interviews revealed a new theme, namely the key features of mHealth, with three sub-themes: availability of services for caregivers, provision of knowledge skills, and supporting caregivers in managing stroke patients. Conclusion: Healthcare providers demonstrated excellent acceptability of this mHealth intervention as part of caregiving assistance, particularly with the inclusion of essential key features. However, future investigations are necessary to establish the feasibility of integrating the mHealth app into the healthcare system and to ensure its long-term sustainability.

5.
J Air Waste Manag Assoc ; 73(9): 649-678, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37449903

RESUMEN

Clarifying the spatiotemporal distribution and impact mechanism of pollution is the prerequisite for megacities to formulate relevant air pollution prevention and control measures and achieve carbon neutrality goals. Chongqing is one of the dual-core key megacities in Cheng-Yu region and as a typical mountain-city in China, environmental problems are complex and sensitive. This research aims to investigate the exceeding standard levels and spatio-temporal evolution of criteria pollutants between 2014 and 2020. The results indicated that PM10, PM2.5, CO and SO2 were decreased significantly by 45.91%, 52.86%, 38.89% and 66.67%, respectively. Conversely, the concentration of pollutant O3 present a fluctuating growth and found a "seesaw" phenomenon between it and PM. Furthermore, PM and O3 are highest in winter and summer, respectively. SO2, NO2, CO, and PM showed a "U-shaped", and O3 showed an inverted "U-shaped" seasonal variation. PM and O3 concentrations are still far behind the WHO, 2021AQGs standards. Significant spatial heterogeneity was observed in air pollution distribution. These results are of great significance for Chongqing to achieve "double control and double reduction" of PM2.5 and O3 pollution, and formulate a regional carbon peaking roadmap under climate coordination. Besides, it can provide an important platform for exploring air pollution in typical terrain around the world and provide references for related epidemiological research.Implications: Chongqing is one of the dual-core key megacities in Cheng-Yu region and as a typical mountain city, environmental problems are complex and sensitive. Under the background of the "14th Five-Year Plan", the construction of the "Cheng-Yu Dual-City Economic Circle" and the "Dual-Carbon" goal, this article comprehensively discussed the annual and seasonal excess levels and spatiotemporal evolution of pollutants under the multiple policy and the newest international standards (WHO,2021AQG) backgrounds from 2014 to 2020 in Chongqing. Furthermore, suggestions and measures related to the collaborative management of pollutants were discussed. Finally, limitations and recommendations were also put forward.Clarifying the spatiotemporal distribution and impact mechanism of pollution is the prerequisite for cities to formulate relevant air pollution control measures and achieve carbon neutrality goals. This study is of great significance for Chongqing to achieve "double control and double reduction" of PM2.5 and O3 pollution, study and formulate a regional carbon peaking roadmap under climate coordination and an action plan for sustained improvement of air quality.In addition, this research can advanced our understanding of air pollution in complex terrain. Furthermore, it also promote the construction of the China national strategic Cheng-Yu economic circle and build a beautiful west. Moreover, it provides scientific insights for local policymakers to guide smart urban planning, industrial layout, energy structure, and transportation planning to improve air quality throughout the Cheng-Yu region. Finally, this is also conducive to future scientific research in other regions of China, and even megacities with complex terrain in the world.

6.
Water Air Soil Pollut ; 234(5): 328, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37200574

RESUMEN

Currently, air quality has become central to global environmental policymaking. As a typical mountain megacity in the Cheng-Yu region, the air pollution in Chongqing is unique and sensitive. This study aims to comprehensively investigate the long-term annual, seasonal, and monthly variation characteristics of six major pollutants and seven meteorological parameters. The emission distribution of major pollutants is also discussed. The relationship between pollutants and the multi-scale meteorological conditions was explored. The results indicate that particulate matter (PM), SO2 and NO2 showed a "U-shaped" variation, while O3 showed an "inverted U-shaped" seasonal variation. Industrial emissions accounted for 81.84%, 58% and 80.10% of the total SO2, NOx and dust pollution emissions, respectively. The correlation between PM2.5 and PM10 was strong (R = 0.98). In addition, PM only showed a significant negative correlation with O3. On the contrary, PM showed a significant positive correlation with other gaseous pollutants (SO2, NO2, CO). O3 is only negatively correlated with relative humidity and atmospheric pressure. These findings provide an accurate and effective countermeasure for the coordinated management of air pollution in Cheng-Yu region and the formulation of the regional carbon peaking roadmap. Furthermore, it can improve the prediction accuracy of air pollution under multi-scale meteorological factors, promote effective emission reduction paths and policies in the region, and provide references for related epidemiological research. Supplementary Information: The online version contains supplementary material available at 10.1007/s11270-023-06279-8.

7.
Fire Technol ; 59(1): 247-270, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35637789

RESUMEN

In recent years, it is evident that there is a surge in photovoltaic (PV) systems installations on buildings. It is concerning that PV system related fire incidents have been reported throughout the years. Like any other electrical power system, PV systems pose fire and electrical hazards when at fault. As a consequence, PV fires compromised the safety of emergency responders. Therefore, the objective of this review is to evaluate the elements of firefighters' safety practices and subsequently collate the best safety practices for local fire rescue and firefighters in the event of PV fires. Out of 264 documents, only 20 publications were identified as 'closely related' and were systematically reviewed to evaluate firefighter safety practices from a scholarly perspective. Only 3% of the 20 publications reviewed, discussed the safety practices during PV fires. Thirteen safety practice key points were extracted from the reviewed documents, with nine critical findings highlighted as the hallmark of safety practices during PV fire for firefighters. The lack of academic journals discussing the fire safety aspects proves that there is a low interest in this field which is in dire need of further study and exploration to adhere with the PV population in ensuring a reliable emergency operation to minimize losses or injuries due to accidents.

8.
Phys Med Biol ; 67(23)2022 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-36356317

RESUMEN

'Objective. Dead time correction (DTC) is an important factor in ensuring accurate quantification in PET measurements. This is currently often achieved using a global DTC method, i.e., an average DTC factor is computed. For PET scanners designed to image dedicated organs, e.g., those used in brain imaging or positron emission mammography (PEM), a substantial amount of the administered radioactivity is located outside of the PET field-of-view (FOV). This activity contributes to the dead time (DT) of the scintillation detectors. Moreover, the count rates of the individual scintillation detectors are potentially very inhomogeneous due to the specific irradiation of each detector, especially for combined MR/PET systems, where radiation shields cannot be applied. Approach: We have developed a block-pairwise DTC method for our Siemens 3T MR BrainPET insert by extending a previously published method that uses the delayed random coincidence count rate to estimate the DT in the individual scans and planes (i.e., scintillation pixel rings). The method was validated in decay experiments using phantoms with a homogenous activity concentration and with and without out-of-FOV activity. Based on a three-compartment phantom, we compared the accuracy and noise properties of the block-pairwise DTC and the global DTC method.Main results. The currently used global DTC led to a substantial positive bias in regions with high activity; the block-pairwise DTC resulted in substantially less bias. The noise level for the block-pairwise DTC was comparable to the global DTC and image reconstructions without any DTC. Finally, we tested the block-pairwise DTC with a data set obtained from volunteer measurements using the mGluR5 (metabotropic glutamate receptor subtype 5) antagonist [11C]ABP688. When the relative differences in activity concentrations obtained with global DTC and block-pairwise DTC for the ACC and the cerebellum GM were compared, the ratios differed by a factor of up to 1.4 at the beginning-when the first injection is administered as a bolus with high radioactivity.Significance. In this work, global DTC was shown to have the potential to introduce quantification bias, while better quantitation accuracy was achieved with the presented block-pairwise DTC method. The method can be implemented in all systems that use the delayed window technique and is particulary expected to improve the quantiation accuracy of dedicated brain PET scanners due to their geometry.'


Asunto(s)
Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X , Humanos , Tomografía de Emisión de Positrones/métodos , Fantasmas de Imagen , Procesamiento de Imagen Asistido por Computador , Encéfalo/diagnóstico por imagen
9.
J Med Phys ; 47(2): 189-193, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36212205

RESUMEN

Peptide Receptor Radionuclide Therapy (PRRT) is the administration of a radionuclide, such as the Lu-177 label, along with a pharmaceutical agent to destroy the lesion cell. The first cycle of Lu-177 DOTA-TATE is an excellent way to estimate radionuclide uptake for organs at risk. To estimate the absorbed dose for a kidney, serial SPECT-CT imaging with up to five sets is required. In general, serial CT on patients would result in additional external exposure and extra time consuming, especially for low dose CT such as cone beam CT technology. However, by introducing a new method, such as optimized single CT (24 h) to perform with serial SPECT attenuation correction, additional external exposure from serial CT exposure could be reduced. Aims: The purpose of this study is to assess the agreement between single CT scanning as CT attenuation Correction with serial CT scanning for serial SPECT imaging as well as estimated absorbed dose to the organ at risk. Settings and Design: During the first cycle of Lu177-DOTA-TATE, all patients should undergo internal dosimetry technique using SPECT-CT imaging with a PHILIP Brightview XCT gamma camera. The quantifications of SPECT images are being used to measure the uptake activity to the organ. In this investigation, Partik's categorical grading criteria are being used to convert the numeric value of Lin's concordance coefficient into an ordinal scale. Method: Total of 9 patients at our institution was administered with Lu177-DOTA-TATE enroll in this study. SPECT-CT data were acquired using automatic body contouring with a total of 48 angular views at steps of 6° (15 s/projections). The pixel size is 4.66 x 4.66 x 4.66 mm, the images size set to one, and SPECT data has been acquired for three-bed positions extending from the abdomen to the thorax region. Low-dose CT imaging performed at an X-ray tube voltage of 120 kVp. Results: Our current result demonstrated by single CT scanning for SPECT attenuation shown the excellent agreement with standard serial CT imaging for organs at risk such as kidney 0.999, spleen 0.9951, liver 0.9951 and bladder 0.9972. Conclusions: When compared to the previous method, patients benefit significantly more from this study, such as lower CT exposure.

10.
Malays J Med Sci ; 29(6): 123-131, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36818910

RESUMEN

Background: Understanding the risks of COVID-19 mortality helps in the planning and prevention of the disease. This study aimed to determine the risk factors for COVID-19 mortality in Malaysia. Methods: Secondary online data provided by the Ministry of Health, Malaysia and Malaysia's national COVID-19 immunisation programme were used: i) COVID-19 deaths data; ii) vaccination coverage data and iii) population estimate data. Quasi-Poisson regression was performed to determine the risk factors for COVID-19 mortality. Results: Four risk factors were identified: i) vaccination status (partial versus unvaccinated, incidence rate ratio [IRR]: 0.59; 95% CI: 0.54, 0.64; complete versus unvaccinated, IRR: 0.50; 95% CI: 0.45, 0.56; booster versus unvaccinated, IRR: 0.13; 95% CI: 0.05, 0.26); ii) age group (19 years old-59 years old versus above 60 years old, IRR: 0.90; 95% CI: 0.84, 0.97; 13 years old-18 years old versus above 60 years old, IRR: 0.09; 95% CI: 0.04, 0.19; 6 years old-12 years old versus above 60 years old, IRR: 0.09; 95% CI: 0.03, 0.22; below 5 years old versus above 60 years old, IRR: 0.11; 95% CI: 0.04, 0.23); iii) gender (male versus female, IRR: 1.23; 95% CI: 1.14, 1.32) and iv) comorbidity (yes versus no, IRR: 2.13; 95% CI: 1.96, 2.32). Conclusion: This study highlighted the risk factors for COVID-19 mortality and the benefit of COVID-19 vaccination, especially of booster vaccination, in reducing the risk of COVID-19 mortality in Malaysia.

11.
PeerJ ; 9: e11886, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34395099

RESUMEN

This study aimed to reveal the habitat variables that determine the distribution and abundance of the land snail Pollicaria elephas in limestone habitats in Perak, Malaysia. Seventeen plots were selected on a limestone hill to determine the effect of environmental variables on the abundance of this land snail. The environmental variables we considered included habitat (canopy cover and leaf litter thickness), topography (elevation, aspect, ruggedness, and slope), microclimate (soil temperature, air temperature, and humidity), and vegetation (abundance of respective vascular plant species). The correlation analyses suggested that the snails' abundance was positively correlated with the abundance of the four vascular plant species: Diospyros toposia var. toposoides, Croton cascarilloides, Kibatalia laurifolia, and Mallotus peltatus. Plots with lower soil temperatures had more snails than plots with higher soil temperatures. Our results show that plots in the southern part of the limestone hill, in which P. elephas were absent, were similar in habitat, topography, microclimate, and vegetation to the plots in the northern part of the limestone hill, where specimens were mostly present. The absence of this species in suitable habitats may be due to their low dispersal ability rather than adverse environmental conditions.

12.
J Arthroplasty ; 36(12): 3993-4002.e37, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34275710

RESUMEN

BACKGROUND: Total knee arthroplasty (TKA) is widely considered a successful intervention for osteoarthritis and other degenerative knee diseases. This study addresses the need for a high-quality meta-analysis that outlines the clinical course of pain and function post-TKA. METHODS: The review included prospective cohort studies assessing pain or function of patients undergoing primary TKA at baseline (preoperatively) and at least 2 additional time points including one at least 12 months postoperatively. Two reviewers independently screened references, extracted data, and assessed risk of bias using the Quality in Prognosis Studies tool. The time course of recovery of pain and function was modeled using fractional polynomial meta-regression. RESULTS: In total, 191 studies with 59,667 patients were included, most with low risk of bias. The variance-weighted mean pain score (/100, 0 = no pain) was 64.0 (95% confidence interval [CI] 60.2-67.7) preoperatively, 24.1 (95% CI 20.3-27.9) at 3 months, 20.4 (95% CI 16.7-24.0) at 6 months, and 16.9 (95%CI 13.6-20.3) at 12 months, and remained low (10.1; 95% CI 4.8-15.4) at 10 years postoperatively. The variance-weighted mean function score (/100, 0 = worst function) was 47.1 (95% CI 45.7-48.4) preoperatively, 72.8 (95% CI 71.3-74.4) at 3 months, 76.3 (95% CI 74.7-77.8) at 6 months, and 78.1 (95%CI 76.4-79.7) at 12 months. Function scores were good (79.7; 95% CI 77.9-81.5) at 10 years postoperatively. CONCLUSION: Patients undergoing primary TKA can expect a large and rapid but incomplete recovery of pain and function in the first postoperative year. At 10 years, the gains in pain scores may still remain while there is an improvement in function.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Osteoartritis de la Rodilla , Artroplastia de Reemplazo de Rodilla/efectos adversos , Humanos , Articulación de la Rodilla/cirugía , Osteoartritis de la Rodilla/cirugía , Dimensión del Dolor , Dolor Postoperatorio/diagnóstico , Dolor Postoperatorio/epidemiología , Dolor Postoperatorio/etiología , Estudios Prospectivos , Resultado del Tratamiento
13.
Chemosphere ; 271: 129502, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33465622

RESUMEN

Most developing countries in the world face the common challenges of reducing air pollution and advancing the process of sustainable development, especially in China. Air pollution research is a complex system and one of the main methods is through numerical simulation. The air quality model is an important technical method, it allows researchers to better analyze air pollutants in different regions. In addition, the SCB is a high-humidity and foggy area, and the concentration of atmospheric pollutants is always high. However, research on this region, one of the four most polluted regions in China, is still lacking. Reviewing the application of air quality models in the SCB air pollution has not been reported thoroughly. To fill these gaps, this review provides a comprehensive narration about i) The status of air pollution in SCB; ii) The application of air quality models in SCB; iii) The problems and application prospects of air quality models in the research of air pollution. This paper may provide a theoretical reference for the prevention and control of air pollution in the SCB and other heavily polluted areas in China and give some1inspirations for air pollution forecast in other countries with complex terrain.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , China , Monitoreo del Ambiente , Material Particulado/análisis
14.
Ann Nucl Med ; 34(12): 884-891, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33141408

RESUMEN

OBJECTIVE: 18F is the most extensively used radioisotope in current clinical practices of PET imaging. This selection is based on the several criteria of pure PET radioisotopes with an optimum half-life, and low positron energy that contributes to a smaller positron range. In addition to 18F, other radioisotopes such as 68Ga and 124I are currently gained much attention with the increase in interest in new PET tracers entering the clinical trials. This study aims to determine the minimal scan time per bed position (Tmin) for the 124I and 68Ga based on the quantitative differences in PET imaging of 68Ga and 124I relative to 18F. METHODS: The European Association of Nuclear Medicine (EANM) procedure guidelines version 2.0 for FDG-PET tumor imaging has adhered for this purpose. A NEMA2012/IEC2008 phantom was filled with tumor to background ratio of 10:1 with the activity concentration of 30 kBq/ml ± 10 and 3 kBq/ml ± 10% for each radioisotope. The phantom was scanned using different acquisition times per bed position (1, 5, 7, 10 and 15 min) to determine the Tmin. The definition of Tmin was performed using an image coefficient of variations (COV) of 15%. RESULTS: Tmin obtained for 18F, 68Ga and 124I were 3.08, 3.24 and 32.93 min, respectively. Quantitative analyses among 18F, 68Ga and 124I images were performed. Signal-to-noise ratio (SNR), contrast recovery coefficients (CRC), and visibility (VH) are the image quality parameters analysed in this study. Generally, 68Ga and 18F gave better image quality as compared to 124I for all the parameters studied. CONCLUSION: We have defined Tmin for 18F, 68Ga and 124I SPECT CT imaging based on NEMA2012/IEC2008 phantom imaging. Despite the long scanning time suggested by Tmin, improvement in the image quality is acquired especially for 124I. In clinical practice, the long acquisition time, nevertheless, may cause patient discomfort and motion artifact.


Asunto(s)
Elementos Radiactivos/química , Marcaje Isotópico/métodos , Neoplasias/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de Positrones/instrumentación , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Composición de Medicamentos , Radioisótopos de Flúor/química , Radioisótopos de Galio/química , Humanos , Procesamiento de Imagen Asistido por Computador/instrumentación , Procesamiento de Imagen Asistido por Computador/métodos , Radioisótopos de Yodo/química , Fantasmas de Imagen , Dosis de Radiación , Trazadores Radiactivos , Relación Señal-Ruido , Factores de Tiempo
15.
Ann Nucl Med ; 34(1): 39-48, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31612417

RESUMEN

OBJECTIVE: Qualitative interpretation in bone scan is often complicated by the presence of degenerative joint disease (DJD), especially in the elderly patient. The aim of this study is to compare objectively 99mTc-MDP tracer uptake between DJD and osseous metastases of the spine using semi-quantitative assessment with SPECT SUV. METHODS: Bone scan with SPECT/CT using 99mTc-MDP was performed in 34 patients diagnosed with prostate carcinoma. SPECT/CT was performed based on our institutional standard guidelines. SUVmax based on body weight in 238 normal vertebrae visualized on SPECT/CT was quantified as baseline. A total of 211 lesions in the spine were identified on bone scan. Lesions were characterized into DJD or bone metastases based on its morphology on low-dose CT. Semi-quantitative evaluation using SUVmax was then performed on 89 DJD and 122 metastatic bone lesions. As most of the bone lesions were small in volume, the effect of partial volume effect (PVE) on SUVmax was also assessed. The corrected SUVmax values were obtained based on the recovery coefficient (RC) method. RESULTS: The mean SUVmax for normal vertebrae was 7.08 ± 1.97, 12.59 ± 9.01 for DJD and 36.64 ± 24.84 for bone metastases. The SUVmax of bone metastases was significantly greater than DJD (p value < 0.05). To assess for diagnostic accuracy, receiver operating characteristic (ROC) curve was performed. The area under the curve (AUC) was found to be fairly high at 0.874 (95% CI 0.826-0.921). The cutoff SUVmax value ≥ 20 gave a sensitivity of 73.8% and specificity of 85.4% in differentiating bone metastases from DJD. The corrected SUVmax for both DJD and bone metastases was smaller with a mean of 6.82 ± 6.02 and 24.77 ± 20.61, respectively. The cutoff SUVmax value was also lower with a value of 10, which gave a sensitivity of 73.8% and specificity of 86.5%. CONCLUSION: SPECT SUVmax was significantly higher in bone metastases than DJD. Semi-quantitative assessment with SUVmax can complement qualitative analysis. A cutoff SUVmax of ≥ 20 can be used to differentiate bone metastases from DJD. Partial volume effect should be taken into consideration in the quantification of small lesion size.


Asunto(s)
Artropatías/diagnóstico por imagen , Neoplasias de la Próstata/patología , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único , Neoplasias de la Columna Vertebral/diagnóstico por imagen , Neoplasias de la Columna Vertebral/secundario , Columna Vertebral/diagnóstico por imagen , Transporte Biológico , Diagnóstico Diferencial , Humanos , Interpretación de Imagen Asistida por Computador , Artropatías/metabolismo , Masculino , Neoplasias de la Columna Vertebral/metabolismo , Medronato de Tecnecio Tc 99m/metabolismo
16.
Entropy (Basel) ; 21(1)2019 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-33266750

RESUMEN

Derived from Lorenz-Haken equations, this paper presents a new 4D chaotic laser system with three equilibria and only two quadratic nonlinearities. Dynamics analysis, including stability of symmetric equilibria and the existence of coexisting multiple Hopf bifurcations on these equilibria, are investigated, and the complex coexisting behaviors of two and three attractors of stable point and chaotic are numerically revealed. Moreover, a conducted research on the complexity of the laser system reveals that the complexity of the system time series can locate and determine the parameters and initial values that show coexisting attractors. To investigate how much a chaotic system with multistability behavior is suitable for cryptographic applications, we generate a pseudo-random number generator (PRNG) based on the complexity results of the laser system. The randomness test results show that the generated PRNG from the multistability regions fail to pass most of the statistical tests.

17.
Zookeys ; (769): 1-11, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29988791

RESUMEN

This paper presents the first land snail species checklist for Gunung Kuang (Kuang Hill), a limestone hill located next to Gunung Kanthan that is recognised as one of the most important limestone hills for its diverse land snail fauna in Kinta Valley. Samplings were carried out at five plots in Gunung Kuang. This survey documented 47 land snail species, in which six species were identified as unique to Gunung Kuang. Approximately half of the land snails from Gunung Kanthan were found in Gunung Kuang. In addition, one of six unique species from Gunung Kanthan was also found in Gunung Kuang. These rich land snail species in Gunung Kuang are similar to other hills in Kinta Valley, but it is relatively lesser than the adjacent Gunung Kanthan. In view of Gunung Kuang's unique land snail species, and its location closest to disturbed Gunung Kanthan, Gunung Kuang should be considered in the conservation management plan for Gunung Kanthan.

18.
J Interferon Cytokine Res ; 35(7): 563-8, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25811314

RESUMEN

Hepatitis C virus (HCV) is a major public health problem. Soluble CD14 (sCD14) level was shown to be associated with HCV infection. In this study, we aimed to investigate the relationship between sCD14 concentration and disease progression, as well as the response to pegylated interferon/ribavirin (peg-IFN/RBV) therapy in Egyptian patients with chronic hepatitis C (CHC). The ELISA technique was used to test 80 patients with CHC and 20 healthy control persons for serum levels of sCD14 (pretreatment and after 12 weeks of treatment). CHC patients were 65 males and 15 females. Normal healthy controls included 20 age- and sex-matched volunteers. The mean age of the CHC patients was 39.94 years, while that of the controls was 39.2 years The serum sCD14 level was significantly higher in chronic HCV-infected patients (3.6±0.18 µg/mL) compared to healthy control subjects (3.1±0.18 µg/mL). The serum sCD14 level was significantly directly correlated with the hepatic fibrosis score (r=0.24, P=0.03), histological activity index (r=0.26, P=0.02), and serum aminotransferases [r=0.28, P=0.005 for alanine aminotransferase (ALT) and r=0.30, P=0.003 for aspartate aminotransferase (AST)]. The pretreatment sCD14 level was not significantly correlated to the treatment response, but it increased after 12 weeks of peg-IFN/RBV therapy and values were significantly higher in nonresponders (P=0.02). The pretreatment sCD14 level cannot predict the treatment response in chronic HCV patients receiving peg-IFN/RBV therapy. However, the serum sCD14 level after 12 weeks of treatment can serve as a negative predictor of treatment response.


Asunto(s)
Progresión de la Enfermedad , Hepatitis C Crónica/sangre , Hepatitis C Crónica/tratamiento farmacológico , Receptores de Lipopolisacáridos/sangre , Adulto , Estudios de Casos y Controles , Demografía , Egipto , Femenino , Hepatitis C Crónica/patología , Humanos , Masculino , Solubilidad
19.
J Dig Dis ; 15(6): 321-6, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24593282

RESUMEN

OBJECTIVE: Malnutrition is prevalent among patients with end-stage liver disease (ESLD) awaiting liver transplantation. Our aim was to examine prospectively the impact of patients' nutritional status on their outcomes after living donor liver transplantation (LDLT). METHODS: In all, 30 patients scheduled for LDLT were subjected to a preoperative nutritional status assessment through subjective global assessment (SGA), nutritional risk screening (NRS 2002) and anthropometric measurements. All patients were followed up for 3 months after LDLT for mortality, graft rejection, number of clinically significant infective episodes, time spent in hospital (ward and intensive care unit [ICU]) and graft failure or dysfunction. RESULTS: All patients were nutritionally compromised (evaluated by SGA and NRS 2002), and were divided into two groups: moderately and severely malnourished. Compared with moderately malnourished patients, severely malnourished patients showed significant postoperative hyperbilirubinemia, higher number of infective episodes and longer ICU stay. Preoperative triceps skinfold and mid-arm circumference were negatively correlated with the number of infective episodes (r = -0.33, P = 0.03 and r = -0.377, P = 0.04, respectively). Moreover, skeletal muscle mass was negatively correlated with postoperative serum alanine aminotransferase level (r = -0.52, P = 0.003) and the number of postoperative infective episodes (r = -0.3, P = 0.04). CONCLUSION: Poor nutritional status of Egyptian patients with ESLD negatively affects the patients' outcomes after LDLT.


Asunto(s)
Enfermedad Hepática en Estado Terminal/cirugía , Trasplante de Hígado/métodos , Donadores Vivos , Desnutrición/complicaciones , Estado Nutricional , Adulto , Antropometría/métodos , Enfermedad Hepática en Estado Terminal/complicaciones , Rechazo de Injerto/etiología , Humanos , Infecciones/etiología , Tiempo de Internación/estadística & datos numéricos , Trasplante de Hígado/efectos adversos , Masculino , Desnutrición/diagnóstico , Persona de Mediana Edad , Evaluación Nutricional , Complicaciones Posoperatorias , Estudios Prospectivos , Resultado del Tratamiento
20.
J Med Food ; 12(2): 394-402, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19459743

RESUMEN

The major component, called curcumin, of turmeric (Curcuma longa L.) (Family Zingiberaceae) powder is responsible for its biological actions. The present study aimed to prove the protective effect of turmeric extract against doxorubicin (DOX)-induced cardiac, hepatic, and renal toxicity as evaluated in rats. Body weight and urine volume of the animal groups under investigation were recorded daily throughout the experimental period. Also, the cardiac, hepatic, and renal toxicities were determined by estimating the changes in serum activities of the enzymes lactate dehydrogenase (LDH) and creatine kinase (CK), serum levels of alanine aminotransferase, aspartate aminotransferase, nitric oxide, albumin, and calcium, and kidney and liver tissue activities of superoxide dismutase and glutathione peroxidase, as well as the contents of glutathione and malondialdehyde. Hyperlipidemia was also determined, and protein and albumin changes in urine were estimated. Biochemical and histopathological findings demonstrate that turmeric extract has multiple therapeutic activities that are beneficially protective, and it has an ameliorative effect against DOX-induced cardiac toxicity and hepatotoxicity and blocks DOX-induced nephrosis. Similarly, turmeric extract inhibited the DOX-induced increase in plasma cholesterol, LDH, and CK. The present findings conclude that the turmeric extract has multiple therapeutic activities that block the cardiac, hepatic, and renal toxicities induced by DOX, and it also possibly acts as a free radical scavenger.


Asunto(s)
Antibióticos Antineoplásicos/toxicidad , Curcuma/química , Curcumina/uso terapéutico , Doxorrubicina/toxicidad , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/tratamiento farmacológico , Fitoterapia , Extractos Vegetales/uso terapéutico , Animales , Antioxidantes/metabolismo , Calcio/sangre , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Creatina Quinasa/sangre , Curcumina/farmacología , Glutatión , Cardiopatías/tratamiento farmacológico , Enfermedades Renales/tratamiento farmacológico , L-Lactato Deshidrogenasa/sangre , Lípidos/sangre , Masculino , Malondialdehído/metabolismo , Óxido Nítrico/metabolismo , Extractos Vegetales/farmacología , Distribución Aleatoria , Ratas , Albúmina Sérica/metabolismo , Transaminasas/sangre , Troponina T/sangre
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