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1.
Article de Anglais | WPRIM | ID: wpr-1042423

RÉSUMÉ

Extracellular vesicles (EVs) function as potent mediators of intercellular communication for many in vivo processes, contributing to both health and disease related conditions. Given their biological origins and diverse functionality from correspondingly unique “cargo” compositions, both endogenous and modified EVs are garnering attention as promising therapeutic modalities and vehicles for targeted therapeutic delivery applications. Their diversity in composition, however, has revealed a significant need for more comprehensive analytical-based characterization methods, and manufacturing processes that are consistent and scalable. In this review, we explore the dynamic landscape of EV research and development efforts, ranging from novel isolation approaches, to their analytical assessment through novel characterization techniques, and to their production by industrial-scale manufacturing process considerations. Expanding the horizon of these topics to EVs for in-human applications, we underscore the need for stringent development and adherence to Good Manufacturing Practice (GMP) guidelines. Wherein, the intricate interplay of raw materials, production in bioreactors, and isolation practices, along with analytical assessments compliant with the Minimal Information for Studies of Extracellular Vesicles (MISEV) guidelines, in conjunction with reference standard materials, collectively pave the way for standardized and consistent GMP production processes.

2.
Chinese Journal of Surgery ; (12): 666-674, 2023.
Article de Chinois | WPRIM | ID: wpr-985796

RÉSUMÉ

Objective: To compare the volumetric changes of cervical disc herniation (CDH) after cervical microendoscopic laminoplasty(CMEL),expansive open-door laminoplasty (EOLP) and conservative treatment. Methods: A retrospective study was conducted involving 101 patients with cervical spondylotic myelopathy(CSM),at the Department of Orthopaedic Surgery,the First Affiliated Hospital of Zhengzhou University from April 2012 to April 2021. The patients included 52 males and 49 females with an age of (54.7±11.8) years(range:25 to 86 years). Among them, 35 patients accepted CMEL treatment,33 patients accepted EOLP treatment,while 33 patients accepted conservative treatment. Volume data of CDH were measured by three-dimensional analysis of the initial and follow-up MRI images. The absorption rate and reprotrusion rate of CDH were calculated. The happening of resorption or reprotrusion was defined when the ratio was greater than 5%. The clinical outcomes and quality of life were evaluated by the Japanese Orthopaedic Association (JOA) score and the neck disability index (NDI).Quantitative data was analyzed by one-way ANOVA with post LSD-t test (multiple comparison) or Kruskal-Wallis test. Categorical data was analyzed by χ2 test. Results: The follow-up time of the CMEL group,EOLP group and the conservative treatment group were (27.6±18.8)months,(21.6±6.9)months and(24.9±16.3)months respectively with no significant difference(P>0.05). Changes of CDH volume in patients:(1) There were 96 CDH of 35 patients in the CMEL group,among which 78 showed absorption. The absorption frequency was 81.3%(78/96) and the absorption rate was ranged 5.9% to 90.9%;9 CDH showed reprotrusion,the reprotrusion frequency was 9.4% (9/96) and the reprotrusion rate was 5.9% to 13.3%;(2) There were 94 CDH of 33 patients in the EOLP group,of which 45 showed absorption. The absorption prevalence was 47.9% (45/94) and the absorption rate was 5.0% to 26.7%;20 CDH showed reprotruded,with the reprotrusion frequency of 21.3% (20/94) and the reprotrusion rate was 5.8% to 28.3%;(3) There were 102 CDH in 33 patients of the conservative group. Among them, 5 showed absorption. The absorption frequency was 4.9% (5/102),and the absorption rate was 7.2% to 14.3%;58 CDH showed reprotruded with the re-protrusion ratio of 56.9% (58/102) and the re-protrusion rate was 5.4% to 174.1%. The absorption ratio and reprotrusion ratio of the CMEL group were statistically different from EOLP group or the conservative group (P<0.01).The absorption ratio and reprotrusion ratio of the EOLP group was different from conservative group (all P<0.01). In terms of clinical outcomes, the excellent/good rate of the JOA score and NDI scores in the CMEL group were different from that of conservative group (all P<0.01) but not from that of the EOLP group(P>0.05). Conclusions: CMEL is an effective method for the treatment of CSM,making CDH easier to resorption compared to the EOLP or conservative treatment,thus making a better decompression effect on the nerves. This study enlightened on a new strategy for the clinical treatment of CSM.


Sujet(s)
Mâle , Femelle , Humains , Adulte , Adulte d'âge moyen , Sujet âgé , Sujet âgé de 80 ans ou plus , Études rétrospectives , Déplacement de disque intervertébral/chirurgie , Traitement conservateur , Qualité de vie , Résultat thérapeutique , Spondylose/chirurgie , Vertèbres cervicales/chirurgie , Maladies de la moelle épinière , Laminoplastie/méthodes , Décompression
3.
Chinese Journal of Surgery ; (12): 681-687, 2023.
Article de Chinois | WPRIM | ID: wpr-985798

RÉSUMÉ

Objective: To investigate the value of inflammation,coagulation and nutrition markers in predicting the failure of prosthesis removal and antibiotic-loaded bone cement spacer implantation for treatment of periprosthetic joint infection(PJI). Methods: A retrospective study was conducted on 70 patients who undertook prosthesis removal and antibiotic-loaded bone cement spacer implantation due to PJI from June 2016 to October 2020 in the Department of Orthopedics,Henan Provincial People's Hospital. There were 28 males and 42 females,aged (65.5±11.9) years (range: 37 to 88 years). Patients were divided into two groups as the successful group and the failed group depended on whether reinfection occurred after prosthesis removal and antibiotic-loaded bone cement spacer implantation at the last follow up. Patient demographics,laboratory values (C-reactive protein (CRP),erythrocyte sedimentation rate (ESR),ESR and CRP ratio (ESR/CRP),white blood cell count(WBC),platelet count(PLT),hemoglobin(HB),total lymphocyte count(TLC),albumin、fibrinogen(FIB),CRP and albumin ratio (CAR),prognostic nutritional index(PNI)),and reinfection rates were assessed. Comparison between groups was conducted by the independent sample t test or χ2test. Receiver operating characteristic (ROC) curve was plotted,and the area under the curve (AUC),optimal diagnostic threshold,sensitivity,and specificity were analyzed to predict the failure of prosthesis removal and antibiotic-loaded bone cement spacer implantation. Results: All patients were followed up for at least two years,and the follow-up time was (38.4±15.2) months (range: 24 to 66 months). Fifteen patients suffered failure after prosthesis removal and antibiotic-loaded bone cement spacer implantation,while the other 55 patients succeeded. The overall failure rate of prosthesis removal and antibiotic-loaded bone cement spacer implantation in PJI treatment was 21.4%. Level of preoperative CRP ((35.9±16.2)mg/L),PLT ((280.0±104.0)×109/L) and CAR (1.3±0.8) in successful group were lower than CRP ((71.7±47.3)mg/L),PLT ((364.7±119.3)×109/L) and CAR (2.5±2.0) in failed group (all P<0.05).Whereas,level of preoperative ESR/CRP (3.3±3.1), Albumin ((35.3±5.2)g/L) and PNI (43.6±6.2) in successful group were higher than ESR/CRP (1.6±1.4),Albumin ((31.3±4.8)g/L) and PNI (39.2±15.1) in failed group (all P<0.05). AUC of ROC curve,optimal threshold value,sensitivity and specificity of CRP,ESR/CRP, PLT, Albumin,CAR and PNI for the predicting failure of prosthesis removal and antibiotic-loaded bone cement spacer implantation were 0.776(95%CI:0.660 to 0.867),35.4 mg/L,86.7%,67.3%;0.725(95%CI:0.605 to 0.825),1.0,60.0%,78.2%;0.713(95%CI:0.593 to 0.815),253,93.3%,47.3%;0.721(95%CI:0.601 to 0.822),35.7,93.3%,49.1%;0.772(95%CI:0.656 to 0.863),1.1,86.7%,67.3%;0.706(95%CI:0.585 to 0.809),45.7,100%,41.8% respectively. Conclusion: In patients with PJI,CRP>35.4,ESR/CRP≤1.0 and CAR>1.1 could predict the failure of prosthesis removal and antibiotic-loaded bone cement spacer implantation.

4.
Chinese Journal of Epidemiology ; (12): 191-195, 2019.
Article de Chinois | WPRIM | ID: wpr-738238

RÉSUMÉ

Objective: To understand the characteristics on major strain subtypes of hepatitis C virus among HIV/HCV co-infected patients, so as to explore the molecular transmission clusters and related risk factors of HCV strains. Methods: A total of 336 newly reported HIV-infected patients were diagnosed as HIV/HCV co-infection in Dehong Dai and Jingpo autonomous prefecture (Dehong) in 2016. We used Nested PCR to amplify CE1 and NS5B genes among 318 samples with plasma levels above 200 μl, before using the combining phylogenetic tree and constructing molecular propagation network method to analyze the related data. Results: A total of 267 HIV/HCV co-infection patients who had met the HCV genotyping requirements were screened the gene subtypes were diversified. Among these genotypes, proportions of 3b, 6n, 6u, 1a, 3a and other subtypes appeared as 32.6% (87/267), 18.4% (49/267), 15.7%(42/267), 13.1%(35/267), 11.2%(30/267) and 9.0%(24/267) respectively. Molecular transmission network of five major HCV genotypes was constructed with a clustering rate of 39.1% (95/243). The clustering rate of subtype 1a was the highest, as 71.4% (25/35). Results from the multivariate logistic regression showed that ethnic minorities other than the Yi and Jingpo (vs. the Han, OR=0.17, 95%CI: 0.04-0.71), the married spouses (vs. the unmarried, OR=0.42, 95%CI: 0.18-0.94), the 6n and 3a subtype (vs. the 3b subtype, OR=0.34, 95%CI: 0.12-0.95; OR=0.22, 95%CI: 0.05-0.93) were more difficult to form transmission clusters. However, the 6u and 1a subtype (vs. the 3b subtype, OR=3.10, 95%CI: 1.21-7.94; OR=4.00, 95%CI: 1.32-12.11) seemed more likely to form the transmission clusters. Conclusion: Ethnicity, marital status and genetic subtypes were factors significantly associated with the formation of transmission clusters related to the major HCV gene subtypes among newly reported HIV/HCV co-infection in Dehong.


Sujet(s)
Humains , Infections opportunistes liées au SIDA/virologie , Asiatiques , Chine/épidémiologie , Co-infection , Génotype , Infections à VIH/virologie , Hepacivirus/isolement et purification , Hépatite C/virologie , Phylogenèse , Réaction de polymérisation en chaîne
5.
Article de Anglais | WPRIM | ID: wpr-690641

RÉSUMÉ

<p><b>OBJECTIVE</b>The aim of this study was to determine the repeatability and reproducibility of optical coherence tomography angiography (OCTA) based on optical microangiography (OMAG) measurements of macular vessels in normal eyes.</p><p><b>METHODS</b>In this prospective cohort study, 40 eyes of 40 healthy volunteers underwent repeated OCTA (Cirrus HD-OCT 5000 angiography system, Carl Zeiss Meditec, Inc.) scans on two separate visit days. On each visit day, the eyes were scanned three times. The following parameters were used to quantitatively describe the OCTA images of the superficial vascular network: vessel area density (VAD), vessel skeleton density (VSD), vessel diameter index (VDI), vessel perimeter index (VPI), vessel complexity index (VCI), flux, and foveal avascular zone (FAZ). Coefficient of variation (CV) and intraclass correlation coefficient (ICC) were calculated for evaluating intravisit and intervisit repeatability, as well as interobserver reproducibility.</p><p><b>RESULTS</b>The measurements showed high repeatability [CVs ⪕ 4.2% (intravisit) and ⪕ 4.6% (intervisit)] and interobserver reproducibility (ICCs ⪖ 0.923) for all parameters.</p><p><b>CONCLUSION</b>This study demonstrated good repeatability and reproducibility of OCTA based on OMAG for the measurement of superficial vessel parameters in normal eyes.</p>


Sujet(s)
Adulte , Femelle , Humains , Mâle , Adulte d'âge moyen , Jeune adulte , Études de cohortes , Études d'évaluation comme sujet , Angiographie fluorescéinique , Normes de référence , Volontaires sains , Traitement d'image par ordinateur , Microvaisseaux , Imagerie diagnostique , Études prospectives , Reproductibilité des résultats , Rétine , Imagerie diagnostique , Vaisseaux rétiniens , Imagerie diagnostique , Tomographie par cohérence optique , Normes de référence
6.
Cancer Research and Treatment ; : 1362-1377, 2018.
Article de Anglais | WPRIM | ID: wpr-717516

RÉSUMÉ

PURPOSE: Tumor xenograft model is an indispensable animal cancer model. In esophageal squamous cell carcinoma (ESCC) research, orthotopic tumor xenograft model establishes tumor xenograft in the animal esophagus, which allows the study of tumorigenesis in its native microenvironment. MATERIALS AND METHODS: In this study,we described two simple and reproducible methods to develop tumor xenograft at the cervical or the abdominal esophagus in nude mice by direct injection of ESCC cells in the esophageal wall. RESULTS: In comparing these two methods, the cervical one presented with more clinically relevant features, i.e., esophageal stricture, body weight loss and poor survival. In addition, the derived tumor xenografts accompanied a rapid growth rate and a high tendency to invade into the surrounding structures. This model was subsequently used to study the anti-tumor effect of curcumin, which is known for its potential therapeutic effects in various diseases including cancers, and its analogue SSC-5. SSC-5 was selected among the eight newly synthesized curcumin analogues based on its superior anti-tumor effect demonstrated in an MTT cell proliferation assay and its effects on apoptosis induction and cell cycle arrest in cultured ESCC cells. Treatment of orthotopic tumor-bearing mice with SSC-5 resulted in an inhibition in tumor growth and invasion. CONCLUSION: Taken together, we have established a clinically relevant orthotopic tumor xenograft model that can serve as a preclinical tool for screening new anti-tumor compounds, e.g., SSC-5, in ESCC.


Sujet(s)
Animaux , Souris , Apoptose , Poids , Carcinogenèse , Carcinome épidermoïde , Points de contrôle du cycle cellulaire , Prolifération cellulaire , Curcumine , Cellules épithéliales , Sténose de l'oesophage , Oesophage , Hétérogreffes , Dépistage de masse , Souris nude , Utilisations thérapeutiques
7.
Chinese Journal of Epidemiology ; (12): 678-681, 2018.
Article de Chinois | WPRIM | ID: wpr-738024

RÉSUMÉ

Objective: To explore distribution of HIV gene subtypes among newly reported HIV/AIDS cases from China and Myanmar in Dehong Dai and Jingpo prefecture of Yunnan province in 2016. Methods: We conducted DNA extractions from newly reported HIV/AIDS cases in 2016. The gag, env and pol genes were amplified by using reverse transcription-PCR (RT-PCR) and sequenced to identify HIV subtypes. Results: A total of 1 112 newly diagnosed HIV cases were reported in Dehong in 2016, and the HIV subtypes were identified for 860 cases. Subtype C was predominant (33.6%), followed by unique recombinant forms (URFs) (28.4%), CRF01_AE (18.6%) and so on. URFs include four recombination, among which the recombination of CRF01_AE and C subtype were predominant. The HIV subtype distribution was associated with nationality and transmission route in HIV/AIDS cases from Myanmar. Conclusions: The gene subtypes of C, URFs and CRF01_AE were mainly distributed; distribution of URFs remained complex and diverse among newly reported HIV/AIDS cases in Dehong in 2016.


Sujet(s)
Humains , Mâle , Séquence nucléotidique , Chine/épidémiologie , Ethnies/génétique , Gènes pol , Génotype , Infections à VIH/génétique , VIH-1 (Virus de l'Immunodéficience Humaine de type 1)/génétique , Phylogenèse , Réaction de polymérisation en chaîne/méthodes , Sérogroupe
8.
Chinese Journal of Epidemiology ; (12): 1206-1209, 2018.
Article de Chinois | WPRIM | ID: wpr-738124

RÉSUMÉ

Objective: To study the prevalence of musculoskeletal disorders (MSDs) and related factors in female greenhouse workers. Method: A questionnaire survey was conducted among 851 female greenhouse workers in Shandong province in 2015. Results: The incidence of MSDs among the female greenhouse workers was 82.79%. For the MSDs in female greenhouse workers, the top four affected body sites were low back (65.82%), knees (49.10%), neck (25.75%) and shoulder (23.47%). Multivariate logistic regression analysis showed that age ≥50 years (OR=2.098, 95%CI: 1.353-3.252), working years ≥20 (OR=1.703, 95%CI: 1.116-2.599), repetitive work (OR=1.903, 95%CI: 1.183-3.061), standing for prolonged time (OR=2.902, 95%CI: 1.183-7.120) and frequent slightly bending down (OR=2.979, 95%CI: 1.823-4.867) were the main risk factors for MSDs in female greenhouse workers. Aiding tools was the protective factor (OR=0.400, 95%CI:0.229-0.697). Conclusions: The findings showed a relatively higher prevalence of MSDs in female greenhouse workers. It is necessary to take appropriate measures to prevent and control the incidence of MSDs in female greenhouse workers.


Sujet(s)
Femelle , Humains , Agriculture , Chine/épidémiologie , Maladies ostéomusculaires/ethnologie , Maladies professionnelles/ethnologie , Prévalence , Facteurs de risque , Enquêtes et questionnaires
9.
Gut and Liver ; : 270-277, 2013.
Article de Anglais | WPRIM | ID: wpr-158241

RÉSUMÉ

Cellular senescence is a biologically irreversible state of cell-growth arrest that occurs following either a replicative or an oncogenic stimulus. This phenomenon occurs as a response to the presence of premalignant cells and appears to be an important anticancer mechanism that keeps these transformed cells at bay. Many exogenous and endogenous triggers for senescence have been recognized to act via genomic or epigenomic pathways. The most common stimulus for senescence is progressive loss of telomeric DNA, which results in the loss of chromosomal stability and eventual unregulated growth and malignancy. Senescence is activated through an interaction between the p16 and p53 tumor-suppressor genes. Senescent cells can be identified in vitro because they express senescence-associated beta-galactosidase, a marker of increased lysosomal activity. Cellular senescence plays an integral role in the prevention and development of both benign and malignant gastrointestinal diseases. The senescence cascade and the cell-cycle checkpoints that dictate the progression and maintenance of senescence are important in all types of gastrointestinal cancers, including pancreatic, liver, gastric, colon, and esophageal cancers. Understanding the pathogenic mechanisms involved in cellular senescence is important for the development of agents targeted toward the treatment of gastrointestinal tumors.


Sujet(s)
Vieillissement , Baies (géographie) , beta-Galactosidase , Vieillissement de la cellule , Instabilité des chromosomes , Côlon , ADN , Épigénomique , Tumeurs de l'oesophage , Maladies gastro-intestinales , Tumeurs gastro-intestinales , Foie , Muqueuse
10.
Article de Chinois | WPRIM | ID: wpr-341115

RÉSUMÉ

Even though mutations in LMNA have been reported in patients with typical dilated cardio-myopathy(DCM)and atrioventricular block(AVB)previously,the purpose of this study was to disclose this novel genetic abnormality in one Chinese family with the atypical phenotype of progressive AVB followed by DCM with normal QRS interval.Genome-wide linkage analysis mapped the AVB gene in this family to a marker at chromosome 1q21.2,where the LMNA gene was located.Direct DNA sequence analysis revealed a heterozygous G to A transition at nucleotide 244 in exon 1 of LMNA,which resulted in an E82K mutation.The E82K mutation co-segregated with all affected individuals in the family,and was not present in 200 normal controls.Further clinical evaluation of mutation carriers showed that 5 of 6 AVB patients exhibited mild DCM with a late onset of age in the fourth and fifth decades.Ejection fractions were documented in 5 patients with DCM,but 4 showed a normal value of ≥50%.Echocardiography showed that atrial dilatation occurred earlier than ventricular dilatation in the patients.This study suggests that progressive AVB with normal QRS interval and accompanying DCM at later stages may represent a distinct type of DCM.The molecular mechanism by which the E82K mutation causes AVB as the prominent phenotype in DCM may be a focus of future studies.

11.
Article de Anglais | WPRIM | ID: wpr-634726

RÉSUMÉ

Even though mutations in LMNA have been reported in patients with typical dilated cardiomyopathy (DCM) and atrioventricular block (AVB) previously, the purpose of this study was to disclose this novel genetic abnormality in one Chinese family with the atypical phenotype of progressive AVB followed by DCM with normal QRS interval. Genome-wide linkage analysis mapped the AVB gene in this family to a marker at chromosome 1q21.2, where the LMNA gene was located. Direct DNA sequence analysis revealed a heterozygous G to A transition at nucleotide 244 in exon 1 of LMNA, which resulted in an E82K mutation. The E82K mutation co-segregated with all affected individuals in the family, and was not present in 200 normal controls. Further clinical evaluation of mutation carriers showed that 5 of 6 AVB patients exhibited mild DCM with a late onset of age in the fourth and fifth decades. Ejection fractions were documented in 5 patients with DCM, but 4 showed a normal value of [Symbol: see text]50%. Echocardiography showed that atrial dilatation occurred earlier than ventricular dilatation in the patients. This study suggests that progressive AVB with normal QRS interval and accompanying DCM at later stages may represent a distinct type of DCM. The molecular mechanism by which the E82K mutation causes AVB as the prominent phenotype in DCM may be a focus of future studies.

12.
Protein & Cell ; (12): 737-751, 2010.
Article de Anglais | WPRIM | ID: wpr-757445

RÉSUMÉ

'Divide and conquer' has been the guiding strategy for the study of protein structure and function. Proteins are divided into domains with each domain having a canonical structural definition depending on its type. In this review, we push forward with the interesting observation that many domains have regions outside of their canonical definition that affect their structure and function; we call these regions 'extensions'. We focus on the highly abundant PDZ (PSD-95, DLG1 and ZO-1) domain. Using bioinformatics, we find that many PDZ domains have potential extensions and we developed an openly-accessible website to display our results ( http://bcz102.ust.hk/pdzex/ ). We propose, using well-studied PDZ domains as illustrative examples, that the roles of PDZ extensions can be classified into at least four categories: 1) protein dynamics-based modulation of target binding affinity, 2) provision of binding sites for macro-molecular assembly, 3) structural integration of multi-domain modules, and 4) expansion of the target ligand-binding pocket. Our review highlights the potential structural and functional importance of domain extensions, highlighting the significance of looking beyond the canonical boundaries of protein domains in general.


Sujet(s)
Animaux , Humains , Sites de fixation , Ligands , Domaines PDZ , Liaison aux protéines , Multimérisation de protéines , Protéines , Chimie
13.
Article de Anglais | WPRIM | ID: wpr-358825

RÉSUMÉ

<p><b>INTRODUCTION</b>Developing effective exercise programmes for the paediatric population is a strategy for decreasing obesity and is expected to help in eventually limiting obesity-associated long-term health and societal impact. In this study, the effects of a 12-week twice weekly additional exercise training, which comprised a combination of circuit-based resistance training and aerobic exercises, in additional to typical physical education sessions, on aerobic fitness, body composition and serum C-reactive protein (CRP) and lipids were analysed in 13- to 14-year-old obese boys contrasted with a control group.</p><p><b>MATERIALS AND METHODS</b>Both the exercise group (EG, n = 12) and control group (CG, n = 12) participated in the typical 2 sessions of 40-minute physical education (PE) per week in schools, but only EG participated in additional 2 sessions per week of 45 to 60 minutes per session of exercise training, which comprised a combination of circuit-based resistance training and aerobic exercises maintained at 65% to 85% maximum heart rate (HRmax = 220 - age). Body composition was measured using dual energy X-ray absorptiometry (DEXA). Fasting serum CRP and blood lipids were analysed pre- and postexercise programme. Aerobic fitness was measured by an objective laboratory submaximal exercise test, PWC170 (Predicted Work Capacity at HR 170 bpm).</p><p><b>RESULTS</b>Exercise training significantly improved lean muscle mass, body mass index, fitness, resting HR, systolic blood pressure and triglycerides in EG. Serum CRP concentrations were elevated at baseline in both groups, but training did not result in a change in CRP levels. In the CG, body weight increased significantly at the end of the 12-week period.</p><p><b>CONCLUSION</b>This study supports the value of an additional exercise training programme, beyond the typical twice weekly physical education classes, to produce physiological benefits in the management of obesity in adolescents, including prevention of weight gain.</p>


Sujet(s)
Adolescent , Humains , Mâle , Protéine C-réactive , Métabolisme , Traitement par les exercices physiques , Lipides , Sang , Obésité , Thérapeutique , Aptitude physique , Physiologie
14.
Article de Anglais | WPRIM | ID: wpr-151116

RÉSUMÉ

PURPOSE: This study is intended to understand the sensitometric charac teristics and the emulsion properties of the commercially available CEA TVS film in comparison with the Kodak X-Omat V film. MATERIAL AND METHODS: For this purpose, we have formulated an analytic expression of the characteristic curves for x-ray film exposed to mixed radiation of electrons, photons, and visible light. This mathematical expression was developed based on reaction-rate and target-hit theories. Unlike previous expressions, it relates optical density to emulsion properties such as grain size and silver bromide content. We have also developed a quantity which characterizes the film response to visible light relative to that to photons and electrons. This quantity could be expressed as a function of grain area. Thus, we have developed mathematical expressions and quantities with which the emulsion properties of the films can be revealed based on the sensitometric characteristics. Demonstrating the use of this analytical study, we exposed CEA and Kodak verification films to the mixed radiation of electrons, photons, and visible light, and interpreted the experimental results accordingly. RESULTS: We have demonstrated that: (1) the saturation density increases as the silver bromide content increases, (2) the time required to reach the threshold dose (to which the film begins to respond) when films are exposed to visible light decreases as the grain size increases, and (3) the CEA film contains more silver bromide, whereas the Kodak film contains larger grains. These findings were supported by the data provided by the manufacturers afterward. CONCLUSION: This study presented an analytical and experimental basis for understanding the response of X-ray film with respect to the emulsion properties.


Sujet(s)
Grains comestibles , Lumière , Photons , Argent , Film radiographique
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