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Patient skin dose measurements during coronary interventional procedures using Gafchromic film

Ying CK, Kandaiya S

J Radiol Prot, 2010 Sep;30(3):585-96.
PMID: 20826892 DOI: 10.1088/0952-4746/30/3/012

Interventional cardiology (IC) procedures are known to give high radiation doses to patients and cardiologists as they involve long fluoroscopy times and several cine runs. Patients' dose measurements were carried out at the cardiology department in a local hospital in Penang, Malaysia, using Gafchromic XR-RV2 films. The dosimetric properties of the Gafchromic film were first characterised. The film was energy and dose rate independent but dose dependent for the clinically used values. The film had reproducibility within ± 3% when irradiated on three different days and hence the same XR-RV2 dose-response calibration curve can be used to obtain patient entrance skin dose on different days. The increase in the response of the film post-irradiation was less than 4% over a period of 35 days. For patient dose measurements, the films were placed on the table underneath the patient for an under-couch tube position. This study included a total of 44 patients. Values of 35-2442 mGy for peak skin dose (PSD) and 10.9-344.4 Gy cm(2) for dose-area product (DAP) were obtained. DAP was found to be a poor indicator of PSD for PTCA procedures but there was a better correlation (R(2) = 0.7344) for CA + PTCA procedures. The highest PSD value in this study exceeded the threshold dose value of 2 Gy for early transient skin injury recommended by the Food and Drug Administration.
Fulltext Characterization of the Mixed Radiation Field Produced by Carbon and Oxygen Ion Beams of Therapeutic Energy: A Monte Carlo Simulation Study

Ying CK, Bolst D, Rosenfeld A, Guatelli S

J Med Phys, 2019 12 11;44(4):263-269.
PMID: 31908385 DOI: 10.4103/jmp.JMP_40_19

Purpose: The main advantages of charged particle radiotherapy compared to conventional X-ray external beam radiotherapy are a better tumor conformality coupled with the capability of treating deep-seated radio-resistant tumors. This work investigates the possibility to use oxygen beams for hadron therapy, as an alternative to carbon ions.
Materials and Methods: Oxygen ions have the advantage of a higher relative biological effectiveness (RBE) and better conformality to the tumor target. This work describes the mixed radiation field produced by an oxygen beam in water and compares it to the one produced by a therapeutic carbon ion beam. The study has been performed using Geant4 simulations. The dose is calculated for incident carbon ions with energies of 162 MeV/u and 290 MeV/u, and oxygen ions with energies of 192 MeV/u and 245 MeV/u, and hence that the range of the primary oxygen ions projectiles in water was located at the same depth as the carbon ions.
Results: The results show that the benefits of oxygen ions are more pronounced when using lower energies because of a slightly higher peak-to-entrance ratio, which allows either providing higher dose in tumor target or reducing it in the surrounding healthy tissues. It is observed that, per incident particle, oxygen ions deliver higher doses than carbon ions.
Conclusions: This result coupled with the higher RBE shows that it may be possible to use a lower fluence of oxygen ions to achieve the same therapeutic dose in the patient as that obtained with carbon ion therapy.
Fulltext Quantification of intracellular payload release from polymersome nanoparticles

Scarpa E, Bailey JL, Janeczek AA, Stumpf PS, Johnston AH, Oreffo RO, et al.

Sci Rep, 2016 07 11;6:29460.
PMID: 27404770 DOI: 10.1038/srep29460

Polymersome nanoparticles (PMs) are attractive candidates for spatio-temporal controlled delivery of therapeutic agents. Although many studies have addressed cellular uptake of solid nanoparticles, there is very little data available on intracellular release of molecules encapsulated in membranous carriers, such as polymersomes. Here, we addressed this by developing a quantitative assay based on the hydrophilic dye, fluorescein. Fluorescein was encapsulated stably in PMs of mean diameter 85 nm, with minimal leakage after sustained dialysis. No fluorescence was detectable from fluorescein PMs, indicating quenching. Following incubation of L929 cells with fluorescein PMs, there was a gradual increase in intracellular fluorescence, indicating PM disruption and cytosolic release of fluorescein. By combining absorbance measurements with flow cytometry, we quantified the real-time intracellular release of a fluorescein at a single-cell resolution. We found that 173 ± 38 polymersomes released their payload per cell, with significant heterogeneity in uptake, despite controlled synchronisation of cell cycle. This novel method for quantification of the release of compounds from nanoparticles provides fundamental information on cellular uptake of nanoparticle-encapsulated compounds. It also illustrates the stochastic nature of population distribution in homogeneous cell populations, a factor that must be taken into account in clinical use of this technology.
Digitation associated with defecation: what does it mean in urogynaecological patients?

Hai-Ying C, Guzmán Rojas R, Hall JC, Atan IK, Dietz HP

Int Urogynecol J, 2016 Feb;27(2):229-32.
PMID: 26264476 DOI: 10.1007/s00192-015-2813-7

INTRODUCTION AND HYPOTHESIS: Obstructed defecation is a common symptom complex in urogynaecological patients, and perineal, vaginal and/or anal digitation may required for defecation. Translabial ultrasound can be used to assess anorectal anatomy, similar to defecation proctography. The aim of the present study was to determine the association between different forms of digitation (vaginal, perineal and anal) and abnormal posterior compartment anatomy.
METHODS: A total of 271 patients were analysed in a retrospective study utilising archived ultrasound volume datasets. Symptoms of obstructed defecation (straining at stool, incomplete bowel emptying, perineal, vaginal and anal digitation) were ascertained on interview. Postprocessing of stored 3D/4D translabial ultrasound datasets obtained on maximal Valsalva was used to diagnose descent of the rectal ampulla, rectocoele, enterocoele and rectal intussusception at a later date, blinded to all clinical data.
RESULTS: Digitation was reported by 39 % of our population. The position of the rectal ampulla on Valsalva was associated with perineal (p = 0.02) and vaginal (p = 0.02) digitation. The presence of a true rectocoele was significantly associated with perineal (p = 0.04) and anal (p = 0.03) digitation. Rectocoele depth was associated with all three forms of digitation (P = 0.005-0.02). The bother of symptoms of obstructed defecation was strongly associated with digitation (all P
Fulltext Association of Internet Addiction with Adolescents' Lifestyle: A National School-Based Survey

Ying Ying C, Awaluddin SM, Kuang Kuay L, Siew Man C, Baharudin A, Miaw Yn L, et al.

Int J Environ Res Public Health, 2020 12 29;18(1).
PMID: 33383635 DOI: 10.3390/ijerph18010168

Internet addiction (IA) among adolescents is an issue of growing concern with adverse effects on adolescents' health and social functioning. This study aims to determine the prevalence of IA among school-going adolescents in Malaysia and its associated factors-specifically, lifestyle factors. A nationwide cross-sectional school-based health survey was conducted in 2017 among 27,497 students from 212 randomly selected secondary schools. Information regarding sociodemography, lifestyle, and internet use was obtained using a self-administered questionnaire. IA was measured using the Malay Version of Internet Addiction Test (MVIAT). The prevalence of internet addiction was 29.0%. A multivariable logistic analysis revealed that inadequate fruit and vegetable intakes, consumed carbonated soft drinks at least once a day, consumed fast food at least three days/week, sedentary behavior, current E-cigarette users, and ever/current alcohol drinkers were lifestyle factors significantly associated with IA. Adolescents from urban schools, of higher school grade, and those whose parents are married but living apart were also found to have a greater risk for internet addiction. A positive association was found between IA with unhealthy dietary and lifestyle behaviors among adolescents. The modification of lifestyle factors needs to be considered while developing strategies and interventions for awareness-raising and prevention of IA among adolescents.
The Association of Internet Addiction and Perceived Parental Protective Factors Among Malaysian Adolescents

Awaluddin SMB, Ying Ying C, Yoep N, Paiwai F, Lodz NA, Muhammad EN, et al.

Asia Pac J Public Health, 2019 Nov;31(8_suppl):57S-64S.
PMID: 31523984 DOI: 10.1177/1010539519872642

Parental protective factors do play an important role in preventing Internet addiction. A self-administered questionnaire was used to measure health risk behaviors among Malaysian adolescents. The prevalence of Internet addiction was significantly higher among adolescents with perceived lack of parental supervision (30.1% [95% confidence interval (CI) = 28.7-31.4]) and lack of parental connectedness (30.1% [95% CI = 28.5-31.7]), compared with their counterparts. Adolescents who perceived a lack of parental supervision, respect for privacy, connectedness, and bonding were more likely to have Internet addiction: (adjusted odds ratio [aOR] = 1.39; 95% CI = 1.27-1.52), (aOR = 1.23; 95% CI = 1.16-1.31), (aOR = 1.09; 95% CI = 1.02-1.16), (aOR = 1.06; 95% CI = 1.00-1.12), respectively. Among girls, Internet addiction was associated with those who perceived lack in all 4 parental factors, while among boys, those who perceived lack of parental supervision and respect for privacy were more prone to Internet addiction.
Discrimination of Dioscorea species (Chinese yam) using FT-IR integrated with chemometric approach

Jingying C, Baocai L, Ying C, Wujun Z, Yunqing Z, Yingzhen H, et al.

Spectrochim Acta A Mol Biomol Spectrosc, 2023 Dec 15;303:123229.
PMID: 37625275 DOI: 10.1016/j.saa.2023.123229

Dioscorea oppositifolia is an important crop and functional food. D. oppositifolia tuber is often adulterated with D. persimilis, D. alata, and D. fordii tuber in the commercial market. This study proposed an integrated Fourier transform infrared spectroscopy (FT-IR) with chemometric approach to differentiate these four Dioscorea species. A total of 107 Dioscorea spp. tuber samples were collected from different locations in China. Principal Component Analysis (PCA), PCA-Class, and Orthogonal Partial Least Square Discriminant Analysis (OPLS-DA) were utilised to classify the FT-IR spectra. In this PCA is unable to differentiate the Dioscorea spp. tuber effectively. However, PCA-Class and OPLS-DA can distinguish spp. these 4 species Dioscorea tuber with high accuracy, sensitivity, and specificity. Additionally, the RMSEE, RMSEP and RMSECV values for OPLS-DA model were low, showing that it is a good model. The combination of FT-IR with the PCA-Class and OPLS-DA is practical in discriminating Dioscorea spp. tubers.