Intra- and inter-examiner reliability for diagnostic criteria of temporomandibular disorders (DC/TMD) - axis 1: assessment in a sample of students

Objective: The aim of this study was to analyze the intra- and inter-examiner reliability when using the DC/TMD axis 1 and verify the replicability and validity of the data obtained.Methods: The sample comprised 30 volunteers (students) of the Instituto Universitário de Ciências da Saúde Norte (Portugal). The calibration process consisted of a volunteer selection, theoretical and practical training, data collection, and agreement calculation. Examiners received proper previous training. Three dental practitioners applied the questionnaire (T1) and re-examined all the participants one week later (T2). To measure the degree of inter and intra-examiner agreement, multiple Kappa coefficients were obtained when nominal or ordinal variables were involved. When the correspondence between quantifiable variables was assessed, Pearson correlation coefficients and their statistical significance were replicated.Results: Regarding opening patterns, a strong overall agreement was obtained, only showing discrepancies in left-assisted and unassisted maximum openings (from -0.034 to -0.370 and -0.630 to -0.933, respectively). A high level of inter-examiner agreement during TMJ noise during the opening assessment was obtained, only displaying variations in clicks (Kappa -0.423 to 0.757). Protrusion movement showed negative kappa and weaker agreement of all measurements (Kappa between -0.034 and -0037). Small discrepancies were obtained from palpation assessment (left lateral pole- Kappa -0.034).Conclusion: There was no discernible and persistent difference in the amount of agreement among the three examiners, demonstrating that all three examiners were capable of participating in data collecting by employing the DC/TMD questionnaire. The findings indicated nearly perfect intra- and inter-examiner concordance scores.

Analysis of food sample composition for gamma spectrometry-based sourceless efficiency simulation / 中华放射医学与防护杂志

Objective:To recommend reference composition for sourceless efficiency calibration of food gamma spectrometry by analyzing the composition of common foods based on a combination of sourceless efficiency calibration and active validation.Methods:Thirty common types of food samples in countrywide monitoring of radioactively contaminated foods were analyzed to statistically determine the reference composition of grains and vegetables. Combined with the parameters provided for white quinoa standard source, LabSOCS was applied to carry out the simulation of sourceless efficiency for its different compositions, and to calculate its measured activity, and analyzing its relative deviation to the those given in the certificate.Results:The analytical result of these 30 types of food samples showed that the five elements C, H, O, N and S accounted for 77.0%-93.7% of the food composition, being the main component of these samples. By applying white quinoa′s components and grain-based reference components to the simulation of the sourceless efficiency of white quinoa standard sources, the relative deviations of activity calculations to their certificated activities were in the range of 0.37%-5.86% and 0.38%-5.87% in absolute value, respectively.Conclusions:The white quinoa′s composition and the grain reference composition were applied to the sourceless efficiency simulation of the white quinoa standard source, and the relative deviation of the calculated measured activity to the activity of the standard source certificate was basically identical, so that if the gamma spectrometry-based sourceless efficiency simulation is used to measure the unknown composition of the food samples and it is inconvenient to carry out the analysis of the food samples′ compositions, especially in the case of emergency, it can be referred to the use of the reference compositions obtained in the present study.

Dose reconstruction of electronic portal imaging device based on calibration and calculation / 中国医学物理学杂志

A dose reconstruction algorithm for electrionic portal imaging device(EPID)based on calibration and calculation is developed.The raw data of EPID in continuous acquisition mode are corrected for dark field and gain,and the gray level features of bright field are used to determine the field boundary.Subsequently,MU calibration,off-axis calibration and field size calibration are performed on the EPID data,and dose reconstruction is carried out based on the calibrated superimposed flux and the Monte Carlo model of the linac head.Nine cases of IMRT plans are selected for verification and measurement using EPID and MapCheck separately,and the passing rates between the two tools are compared under different gamma criteria(3%/3 mm and 2%/2 mm).For a planned case,the average passing rates of multiple cases verified by MapCheck under the two criteria were 99.02%±1.28%and 90.84%±4.49%,and the average passing rates of the EPID reconstruction models were 98.86%±1.19%and 91.39%±4.80%.Compared with MapCheck,the EPID reconstruction algorithm based on calibration and calculation has no significant difference in the passing rate of IMRT plan verification(P＞0.05),which meets the clinical requirements of dose verification.

Study on the calibration for the outputs of photon and electron beams of dual-mode of linear accelerator based on IAEA 277 and 381 reports / 中国医学装备

Objective:To calibrate the absorbed doses of the configured ray water with different gears of energies in accelerator based on<The use of plane-parallel ionization chambers in high-energy electron and photon beams>of International Atomic Energy Agency(IAEA)277 and 381 reports,so as to ensure the accuracy of the output dose of the linear accelerator during clinical radiotherapy.Methods:Elekta Infinity linear accelerator was used in this study,and the photon beam energies were respectively 6MV flattening filter(FF)mode and 6MV flattening filter free(FFF)mode.The electron beam energies were respectively 4,6,8,10,12 and 15MeV.According to the IAEA TRS277 and TRS381 reports,the calibrations of output doses in photon and electron beam waters were performed respectively by using the PTW dosimeter,PTW30013 finger type of ionization chamber and PTW34001 parallel plate ionization chamber.The error of each step was analyzed,and the accuracies of the calibrations of using different standards for the output waters of linear accelerator were compared.Results:The output amounts of photon beams of FF mode and FFF mode of 6MV at the maximum dose point in water were respectively 1.003 and 1.008cGy/MU.The output amounts of the energy of each gear of electron beams of 4,6,8,10,12 and 15MeV at the maximum dose point in water were respectively 1.003,1.002,0.998,0.999,1.000 and 1.003 cGy/MU.The calibration of the output of each gear of energy rays at the maximum dose point in water was 1cCy corresponded to 1MU,which error was less than 1%.Conclusion:The calibration for the output dose amount of accelerator in water on the basis of IAEA TRS277 and trs381 can ensure the accuracy of the output dose of the accelerator.

Transfer of cascade coincidence summing correction factors / 中国辐射卫生

Objective To further extend the application of coincidence summing correction factor transfer experiments through the analysis of relevant measurements. Methods The passive efficiency was simulated using BE5030 high-purity germanium (HPGe) γ-energy spectrometer equipped with LabSOCS, and the total efficiency was simulated using LabSOCS in GENIE 2000 spectrum analysis software, which was used for calculating the coincidence summing correction factor. The coincidence summing correction factor transfer experiments were performed using the measurements with the point source containing 134Cs, 60Co, and 137Cs as well as the body source to obtain the coincidence summing correction factors of other HPGe γ-energy spectrometers. Results The coincidence summing correction factors for 134Cs and 60Co were obtained using the BE5030 γ-energy spectrum. In verification by certificate activity, the absolute value of the maximum deviation was within 3.53%. Using coincidence summing correction factor transfer experiments, these factors were transferred to other high-purity germanium γ spectrometers. In verification by certificate activity, the absolute value of the maximum deviation was within 5.86%. Conclusion The coincidence summing correction factors calculated using simulated total efficiency by calling LabSOCS in the GENIE 2000 spectrum analysis software are effective in correction, and can be used as correction factors in standard laboratories. Through coincidence summing correction factor transfer experiments, the coincidence summing correction of other high-purity germanium γ-energy spectrometers can be achieved, which broadens the application of coincidence summing correction method.

Construction and validation of prediction model for diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To analyze and screen influencing factors of diabetic patients complicated with retinopathy, and establish and validate prediction model of nomogram.METHODS: A total of 1 252 patients from the Diabetes Complications Early Warning Dataset of the National Population Health Data Archive(PHDA)between January 2013 to January 2021 were selected and randomly divided into a modeling group(n=941)and a validation group(n=311). Univariate analysis, LASSO regression and Logistic regression analysis were used to screen out the influencing factors of diabetic retinopathy, and a nomogram prediction model was established. The receiver operating characteristic curve, Hosmer-Lemeshow test and calibration curve were used to evaluate the model. The clinical benefit was evaluated by the decision curve analysis(DCA).RESULTS: Age, hypertension, nephropathy, systolic blood pressure(SBP), glycated hemoglobin(HbA1c), high-density lipoprotein cholesterol(HDL-C), and blood urea(BU)were the influencing factors of diabetic retinopathy. The area under the curve(AUC)of the modeling group was 0.792(95%CI: 0.763-0.821), and the AUC of the validation group was 0.769(95%CI: 0.716-0.822). The Hosmer-Lemeshow goodness of fit test and calibration curve suggested that the theoretical value of the model was in good agreement(modeling group: χ2=14.520, P=0.069; validation group: χ2=14.400, P=0.072). The DCA results showed that the threshold probabilities range was 0.09-0.89 for modeling group and 0.07-0.84 for the validation group, which suggested the clinical net benefit was higher.CONCLUSION: This study constructed a risk prediction model including age, hypertension, nephropathy, SBP, HbA1c, HDL-C, and BU. The model has a high discrimination and consistency, and can be used to predict the risk of diabetic retinopathy in patients with diabetes.

Validation and calibration of the Food Consumption Frequency Questionnaire for pregnant women

ABSTRACT BACKGROUND: Few food frequency questionnaires (FFQ) have been validated for pregnant women, particularly those in small- and medium-sized cities in different regions of Brazil. OBJECTIVES: To validate and calibrate a semiquantitative FFQ for pregnant women. DESIGN AND SETTING: The study was validated with a sample of 50 pregnant women (≥ 18 years) enrolled in Brazilian prenatal services. METHODS: An FFQ and a 24-hour recall were used to evaluate dietary intake. Dietary variables were tested for normality and log-converted when asymmetrical. Pearson's Correlation Coefficient was used to validate the questionnaire. Linear regression was applied to extract calibration factors. All variables underlying the consumption analysis were adjusted for energy. RESULTS: The mean age of the pregnant women was 26 years ± 6.2 years; 58% were in their first trimester, and 30% were identified as overweight/obese. The Pearson correlation analysis results indicated that the FFQ overestimated energy and nutrient intake, whose coefficients ranged from −0.15 (monounsaturated fat) to 0.50 (carbohydrate). Adjusting for energy reduced the mean values of intake coefficients, which now ranged from −0.33 (sodium) to 0.96 (folate). The calibration analysis results indicated variation in the coefficients from −0.23 (sodium) to 1.00 (folate). Calibration produced satisfactory coefficients for the FFQ compared with the reference standard for energy, macronutrients, monounsaturated fat, cholesterol, vitamins B12/C, folate, sodium, iron, and calcium. CONCLUSIONS: After validating and calibrating tests, we observed that the FFQ was adequately accurate for assessing the food consumption of the pregnant women in this study.

Clinimetric properties of the Perme Intensive Care Unit Mobility Score -a multicenter study for minimum important difference and responsiveness analysis

Background: The use of instruments in clinical practice with measurement properties tested is highly recommended, in order to provide adequate assessment and measurement of outcomes. Objective: To calculate the minimum clinically important difference (MCID) and responsiveness of the Perme Intensive Care Unit Mobility Score (Perme Score). Methods: This retrospective, multicentric study investigated the clinimetric properties of MCID, estimated by constructing the Receiver Operating Characteristic (ROC). Maximizing sensitivity and specificity by Youden's, the ROC curve calibration was performed by the Hosmer and Lemeshow goodness-of-fit test. Additionally, we established the responsiveness, floor and ceiling effects, internal consistency, and predictive validity of the Perme Score. Results: A total of 1.200 adult patients records from four mixed general intensive care units (ICUs) were included. To analyze which difference clinically reflects a relevant evolution we calculated the area under the curve (AUC) of 0.96 (95% CI: 0.95-0.98), and the optimal cut-off value of 7.0 points was established. No substantial floor (8.8%) or ceiling effects (4.9%) were observed at ICU discharge. However, a moderate floor effect was observed at ICU admission (19.3%), in contrast to a very low incidence of ceiling effect (0.6%). The Perme Score at ICU admission was associated with hospital mortality, OR 0.86 (95% CI: 0.82-0.91), and the predictive validity for ICU stay presented a mean ratio of 0.97 (95% CI: 0.96-0.98). Conclusion: Our findings support the establishment of the minimum clinically important difference and responsiveness of the Perme Score as a measure of mobility status in the ICU.

Antecedentes: Se recomienda encarecidamente el uso de instrumentos en la práctica clínica con propiedades de medición probadas, con el fin de proporcionar una evaluación y medición adecuada de los resultados. Objetivo: Calcular la diferencia mínima clínicamente importante (MCID) y la capacidad de respuesta de la puntuación de movilidad de la unidad de cuidados intensivos de Perme (Perme Score). Métodos: Este estudio multicéntrico retrospectivo investigó las propiedades clinimétricas de MCID, estimadas mediante la construcción de la característica operativa del receptor (ROC). Maximizando la sensibilidad y especificidad mediante la prueba de Youden, la calibración de la curva ROC se realizó mediante la prueba de bondad de ajuste de Hosmer y Lemeshow. Además, establecimos la capacidad de respuesta, los efectos suelo y techo, la consistencia interna y la validez predictiva del Perme Score. Resultados: Se incluyeron un total de 1,200 registros de pacientes adultos de cuatro unidades de cuidados intensivos (UCI) generales mixtas. Para analizar qué diferencia refleja clínicamente una evolución relevante calculamos el área bajo la curva (AUC) de 0.96 (95% CI: 0.95-0.98); y se estableció el valor de corte óptimo de 7.0 puntos. No se observaron efectos suelo (8.8%) o techo (4.9%) sustanciales al alta de la UCI. Sin embargo, se observó un efecto suelo moderado al ingreso en la UCI (19.3%), en contraste con una incidencia muy baja del efecto techo (0.6%). El Perme Score al ingreso en UCI se asoció con la mortalidad hospitalaria, OR 0.86 (95% CI: 0.82-0.91), y la validez predictiva de estancia en UCI presentó una relación media de 0.97 (95% CI: 0.96-0.98). Conclusiones: Nuestros hallazgos respaldan el establecimiento de la diferencia mínima clínicamente importante y la capacidad de respuesta de el Perme Score como medida del estado de movilidad en la UCI.

Research and Design of Calibration Device for Medical Test Lung / 中国医疗器械杂志

In order to solve the problems of quality control and traceability of medical test lung for meeting the calibration conditions of JJF 1234-2018 Calibration Specification for Ventilators, the calibration device and method are researched for compliance and airway resistance of medical test lung in this paper. A calibration device for medical test lung is designed using constant volume active piston technology to simulate human breathing. Through comparison experiment, the deviation between this device and the similar foreign device can be found. The deviation is lower than 0.4% for lung compliance and lower than 0.7% for airway resistance. The calibration of lung compliance and airway resistance can be completed by this device. This device has a clear and complete traceability path to ensure quality control from the source. The calibration of ventilator is improved. This paper provides a reference for related metrology departments and medical institutions to study on quality inspection of respiratory medical instruments.

Discrete element simulation study of mixing process of Guizhi Fuling Capsules: parameter calibration / 中国中药杂志

The mixing process is a critical link in the formation of oral solid preparations of traditional Chinese medicine. This paper took the extract powder of Guizhi Fuling Capsules and Paeonol powder as research objects. The angle of repose, loose packing density, and particle size of the two powders were measured to calibrate discrete element simulation parameters for the mixing process. The discrete element method was used to calibrate the simulated solid density of Paeonol powder and extract powder of Guizhi Fuling Capsules based on the Hertz-Mindlin with JKR V2 contact model and particle scaling. The Plackett-Burman experimental design was used to screen out the critical contact parameters that had a significant effect on the simulation of the angle of repose. The regression model between the critical contact parameters and the simulated angle of repose was established by the Box-Behnken experimental design, and the critical contact parameters of each powder were optimized based on the regression model. The best combination of critical contact parameters of the extract powder of Guizhi Fuling Capsules was found to be 0.51 for particle-particle static friction coefficient, 0.31 for particle-particle rolling friction coefficient, and 0.64 for particle-stainless steel static friction coefficient. For Paeonol powder, the best combination of critical contact parameters was 0.4 for particle-particle static friction coefficient and 0.19 for particle-particle rolling friction coefficient. The best combination of contact parameters between Paeonol powder and extract powder of Guizhi Fuling Capsules was 0.27 for collision recovery coefficient, 0.49 for static friction coefficient, and 0.38 for rolling friction coefficient. The verification results show that the relative error between the simulated value and the measured value of the angle of repose of the two single powders is less than 1%, while the relative error between the simulated value and the measured value of the angle of repose of the mixed powder with a mass ratio of 1∶1 is less than 4%. These research results provide reliable physical property simulation data for the mixed simulation experiment of extract powder of Guizhi Fuling Capsules and Paeonol powder.

Application of deep learning-based image reconstruction methods combine with the asynchronous calibration quantitative CT for the measurement of bone mineral density / 实用放射学杂志

Objective To investigate the accuracy and reproducibility of deep learning algorithms combined with asynchronous calibration quantitative computed tomography(QCT)for measuring bone mineral density(BMD),and to explore the feasibility of using low-dose scanning BMD measurement.Methods European spine phantom(ESP)was scanned with asynchronous calibration QCT and conventional synchronous calibration QCT,respectively,the accuracy and short-term reproducibility was compared.ESP were scanned with asynchronous calibration QCT,matching 120 kVp with five sets of tube currents:20,60,100,140,and 180 mA.Three levels of deep learning image reconstruction(DLIR)and hybrid model-based adaptive statistical iterative reconstruction V(40％ASIR-V)were used for reconstruction.The BMD values of three vertebrae in the ESP were measured.Furthermore,the image noise and contrast-to-noise ratio(CNR)were compared.Results The relative errors(RE)of the three vertebrae of the asynchronous calibration QCT and synchronous calibration QCT were all less than 7％.There was no statistical difference in the BMD values of the two scans at one week interval of the asynchronous calibration QCT(P＞0.05).There were no significant differences in RE among different tube currents or different reconstruction methods(P＞0.05).The image quality of deep learning-based image reconstruction of high strength(DLIR-H)at 20 mA tube current was better than that of 40％ASIR-V at 180 mA,and the radiation dose was reduced by 89％.Conclusion Asynchronous calibration QCT has high accuracy in BMD measurement,and has good repeatability.Asynchronous calibration QCT which combined with DLIR does not affect the accuracy of BMD measurement,and can significantly improve the CNR of images and reduce image noise.

Development and application progress of standards for antibody against SARS-CoV-2 / 中国生物制品学杂志

@#Coronavirus Disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)seriously threatens human health and public health safety.Vaccination plays an important role in effectively controlling the epidemic situation.More than 150 SARS-CoV-2 vaccines have entered the clinical trial stage and 38 have been approved for emergency use or marketing.Neutralizing antibody level is the main index for evaluation of the immunogenicity of vaccines,but there has been no standardized detection method for SARS-CoV-2 neutralizing antibody till now,which makes it difficult to compare the neutralizing antibody levels among different laboratories and different products horizontally,and seriously restricts the development and evaluation of vaccines and antibody therapeutic drugs.With the rapid sale of the first generation of standards for SARS-CoV-2 antibody and the emergence of variants of concern(VOC)of SARS-CoV-2,WHO and China carried out the development of the second generation of standards simultaneously in 2022.This paper reviews the development and application progress of the standards for SARS-CoV-2 antibody in WHO and China.

Development and application progress of standards for antibody against SARS-CoV-2 / 中国生物制品学杂志

@#Coronavirus Disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)seriously threatens human health and public health safety.Vaccination plays an important role in effectively controlling the epidemic situation.More than 150 SARS-CoV-2 vaccines have entered the clinical trial stage and 38 have been approved for emergency use or marketing.Neutralizing antibody level is the main index for evaluation of the immunogenicity of vaccines,but there has been no standardized detection method for SARS-CoV-2 neutralizing antibody till now,which makes it difficult to compare the neutralizing antibody levels among different laboratories and different products horizontally,and seriously restricts the development and evaluation of vaccines and antibody therapeutic drugs.With the rapid sale of the first generation of standards for SARS-CoV-2 antibody and the emergence of variants of concern(VOC)of SARS-CoV-2,WHO and China carried out the development of the second generation of standards simultaneously in 2022.This paper reviews the development and application progress of the standards for SARS-CoV-2 antibody in WHO and China.

Development of national standards for genomic titer determination of recombinant type 5 adeno-associated virus / 中国生物制品学杂志

@#ObjectiveTo develop a national standard for genomic titer determination of recombinant type 5 adeno-associated virus(rAAV5).MethodsThe rAAV5-GFP stock solution prepared by the three-plasmid system was identified and verified for the appearance,pH,sterility,genomic titer,purity and infection titer according to the relevant requirements of Chinese Pharmacopoeia(Volume Ⅲ,2020 edition),which was diluted and subpackaged to prepare candidate standards according to the results;The stability of candidate standards was investigated by thermal acceleration test;Three laboratories were organized to collaboratively calibrate the candidate standards using droplet digital PCR(ddPCR).ResultsAll the detection indexes of the candidate standard and the stock solution met the relevant requirements;The genomic titer showed no significant decrease at 25,4,-20,-40,-80 ℃ for 1,3,4,6 months;Through collaborative calibration by three laboratories,the candidate standard was assigned a value of 2. 56 × 10(12)copies/mL,and the 95% confidence interval was 2. 48 ×10(12)copies/mL,and the 95% confidence interval was 2. 48 ×10(12)copies/mL ～ 2. 64 × 10(12)copies/mL ～ 2. 64 × 10(12)copies/mL.ConclusionThe developed national standard for the determination of rAAV5 genomic titer had good stability and might be used for the quality evaluation of rAAV5 related products.

Development of a simplified phantom for calibration of whole-body counter / 中国辐射卫生

Objective To develop a simplified phantom for the calibration of whole-body counters. Methods A simplified phantom design method for the calibration of whole-body counters was established based on the process and method of calibrating whole-body counters. By using the established method and Monte Carlo method, a simplified phantom including the total body, thyroid, lungs, and gastrointestinal tract was designed to calibrate the ORTEC-Stand FAST II whole-body counter. The simplified phantom was compared with the BOMAB phantom through experimental measurements. Results Within the range of 50 keV to 2 MeV, for rays of the same energy in the same organ of the simplified phantom and BOMAB phantom, the simulated data of detection efficiency by whole-body counting showed an error within 5%, and the experimental measurements showed an error within 10%. Conclusion We developed a simplified phantom for the calibration of the whole-body counter, demonstrating the feasibility of using the simplified phantom instead of a physical body phantom for whole-body counter calibration, which can greatly facilitate whole-body counter calibration for internal radiation monitoring.

Study on the value of quality detection technology in acceptance of newly purchased medical injection pump / 中国医学装备

Objective:To explore the application value of quality detection technology in the acceptance process of new medical injection pump equipment.Methods:75 sets of medical injection pumps newly purchased by the hospital were selected,and quality inspection and acceptance were carried out by using quality inspection techniques in accordance with the requirements of the Technical Specifications for Quality Inspection of Infusion Pumps and Injection Pumps(Trial).The unqualified equipment was calibrated by a combination of precision calibration,system version upgrade and data import and then the quality inspection was conducted again.Results:The appearance,blocking alarm and alarm prompt function of 75 newly purchased medical injection pumps were all in line with the regulatory requirements.In the flow parameter detection,16 sets were initially detected,11 sets were unqualified,with a failure rate of 68.75%,and 3 of 5 qualified equipment showed a relative error of less than-4.0%.After the equipment was calibrated,the flow parameters were tested again.All 75 medical injection pumps met the regulatory requirements.The absolute value of the relative error of the indication value of 69 medical injection was less than 2.5%,and the absolute value of the relative error of the indication value of only 6 was more than 2.5%.Conclusion:The quality detection technology and calibration method can ensure the safety of clinical use of medical equipment and protect the life and health of patients.

Construction and validation of rectal cancer prognostic model by LASSO-Cox regression / 安徽医科大学学报

Objective To construct and appraise a new model for predicting the prognosis of rectal cancer patients using the Lasso-Cox strategy.Methods The clinical pathological data of 599 rectal cancer patients who underwent radical resection were analyzed.Comparison between groups,Lasso and Cox regression were used to select varia-bles and construct a model,and its discrimination,consistency,and clinical benefits were appraised by the receiv-er operating characteristic(ROC),calibration curve,and decision curve analysis.Results Comparison between groups showed that age,body mass index(BMI),preoperational nutrition status,carbohydrate antigen199(CA199),preoperative chemotherapy,intraoperative blood transfusion,vascular or nerve invasion,cancer nod-ules,pathologic T,N,and TNM stages,tumor recurrence or metastasis,radiotherapy and postoperative survival time were associated with grouping of death or survival in rectal cancer patients.Among them,8 variables were se-lected by lasso and contained into the Cox regression model.Age(HR=1.04,P＜0.05),BMI(HR=0.89,P＜0.05),blood transfusion(HR=2.29,P＜0.05),postoperative chemotherapy(HR=0.16,P＜0.01),recur-rence(HR=43.67,P＜0.01),and metastasis(HR=2.75,P＜0.05)were identified as independent prognostic factors,which were used to construct a nomogram model.The area under the curve(AUC)and the 95％confi-dence interval of the receiver operating characteristic(ROC)curve of the predictive model was 0.95(0.91-0.99),P＜0.01.The predicted probability of 1-year and 3-year survival was close to the actual probability.The DCA curve of the model was far away from a decision line parallel to the X-axis and another line with a negative slope.Conclusion The newly established nomogram has good discrimination,consistency and clinical benefits,which help predict the prognosis of rectal cancer after surgery.

A calibration curve model based on sine function / 中华检验医学杂志

Objective:This paper is to propose a calibration model based on sine function which enables more choices to determine the functional relationship between the absorbance and the concentration of the tested substance.Methods:This paper uses Taylor series expansion and Levenberg-Marquardt to obtain the optimal parameters for the Sine model and then summarizes the characters of the Sine model. On the basis of these characters, this paper compares and evaluates the experimental data processed by the Sine model from four aspects: correctness, precision, linearity and correlation.Results:The generated sine function calibration model achieved deviations within ±3% of the national standard substance, precision ( CV%) less than 2%, and a linear correlation coefficient greater than 0.990 within the measurement range of 32-710 mg/L. The correlation coefficients between the sine model and other well-performing linear calibration models for 104 clinical samples were all greater than 0.990. Conclusions:The performance evaluation of the prealbumin assay kit using the sine function calibration model meets industry standards and shows good correlation with the results of clinical sample measurements. This indicates that the sine function calibration model can serve as a new calibration model for in vitro diagnostic research and clinical applications.

Use of Images and Clinical Experience to Calibrate Dental Surgeons for the Diagnosis of Molar Incisor Hypomineralization

ABSTRACT Objective: To evaluate an imaging protocol for use as a diagnostic and calibration tool for dentists before and after practical activity. Material and Methods: Thirty photos of children's teeth with or without changes in dental enamel were selected and evaluated by a group of experienced dentists previously calibrated to establish the diagnosis defined as the gold standard. After instructions, the images were shown to a group of postgraduate dentists for free identification of dental changes. Subsequently, a lecture on molar incisor hypomineralization (MIH) was carried out, and, at 14 days and all calibration was performed using the criteria previously. The retest was performed at 28 days. After experience in clinical activity in the following two weeks, the post-test was performed at 49 days. Data were analyzed using Cohen's kappa coefficient. Results: Theoretical learning on the subject showed low inter-examiner agreement when the diagnosis of defects was made from images obtained from intraoral photographs. After clinical practice, there was greater intra-examiner agreement. After theoretical training, dentists started to identify different types of enamel alteration, although with low agreement between them. Conclusion: Clinical experience in theoretical and imaging training favored the identification of defects. However, it is necessary to improve the protocol to establish a reliable and viable diagnostic method for calibration in MIH.

Digital X-ray Machine Carestream DRX-NOVA Fault Maintenance / 中国医疗器械杂志

OBJECTIVE@#To analyze the malfunction and maintenance process of Carestream digital X-ray machine DRX-NOVA for reference.@*METHODS@#The fault of Carestream digital X-ray machine DRX-NOVA in 2011-2021 was summarized, the fault types were classified, and the maintenance process was summarized.@*RESULTS@#Fault types can be divided into three categories, each of which has its own characteristics and specific solutions.@*CONCLUSIONS@#It is necessary to master the principle of equipment to repair all kinds of equipment failures. Repair the machine should be careful, comprehensive consideration of the cause of the failure. To correctly understand and analyze the operation of the machine under normal conditions, we can accurately analyze the cause of failure, so that we can really solve the problem.