Application of prediction models in clinical research / 上海预防医学

Chronic diseases have become an important public health problem for people under 70 years of age worldwide， while also causing a great economic burden. The establishment of clinical prediction models can help to predict the risk of a disease or the prognostic effect of a study subject in advance by means of index testing at the early stage of chronic diseases， and plays an increasingly important role in clinical practice. This study introduces clinical diagnostic prediction models and clinical prognostic prediction models， and reviews clinical data processing， clinical prediction model building， visualization methods and model evaluation from the perspective of the application of clinical prediction models， which contribute to the correct and reasonable use of prediction models in clinical research.

Modelo pedagógico para el mejoramiento del sistema de evaluación del residente de Ginecología y Obstetricia / Pedagogical model for improving the evaluation system of gynecology and obstetrics residents

Introducción: El proceso de evaluación en las especialidades médicas tiene su base en la valoración del desempeño para lograr una formación en respuesta al encargo social, lo que requiere de la preparación de los profesores para desarrollar las capacidades que les permitan llevar a cabo un proceso con este enfoque. Objetivo: Proponer un modelo pedagógico para el mejoramiento del sistema de evaluación del residente de Ginecología y Obstetricia en la Facultad de Ciencias Médicas Finlay-Albarrán, en correspondencia con las exigencias sociales y del Sistema Nacional de Salud cubano. Métodos: Se utilizaron métodos teóricos, empíricos y estadísticos, y otros como la parametrización y la triangulación metodológica. La participación de profesores, directivos y residentes del departamento docente de Ginecología y Obstetricia representó el 74,1 por ciento del universo estudiado. Resultados: Se propone un modelo pedagógico que se estructura en dos niveles: conceptual y metodológico. El conceptual comprende los fundamentos teóricos, las ideas científicas, las dimensiones y la finalidad. El metodológico se concreta en su dinámica de aplicación y se organiza en cuatro etapas con objetivos y acciones definidas. Los fundamentos, relacionados entre sí, posibilitaron la organización de las acciones dirigidas para su estructuración. La triangulación metodológica de los resultados de su evaluación valoró positivamente la viabilidad teórica del modelo pedagógico que se presenta. Conclusiones: La modelación como método científico permitió la elaboración de un modelo pedagógico para el mejoramiento del sistema de evaluación del residente de Ginecología y Obstetricia en la Facultad de Ciencias Médicas Finlay-Albarrán. Los resultados obtenidos permitieron declarar su validez teórica(AU)

Introduction: The evaluation process in medical specialties is based on performance evaluation to achieve training in response to the social order, which requires the preparation of teachers to develop the capacities which allow them to carry out a process by this approach. Objective: To propose a pedagogical model for the improvement of the evaluation system of gynecology and obstetrics residents at Finlay-Albarrán Medical Sciences Faculty, in correspondence with the social demands and the Cuban National Health System. Methods: Theoretical, empirical and statistical methods were used, as well as parameterization and methodological triangulation. The participation of professors, directors and residents of gynecology and obstetrics teaching department represented 74.1 percent of the studied universe. Results: A two-level structured pedagogical model is proposed: conceptual and methodological levels. The conceptual level comprises the theoretical foundations, scientific ideas, dimensions and purpose. The methodological level is itemized in application dynamics and it is organized in four stages with defined objectives and actions. The interrelated foundations made possible the organization of actions engaged for structuring. The methodological triangulation of the results of its evaluation positively valued the theoretical viability of the pedagogical model that is presented. Conclusions: Modeling as a scientific method allowed elaborating a pedagogical model for improving the evaluation system of the gynecology and obstetrics resident at Finlay-Albarrán Medical Sciences Faculty. The results obtained allowed to declare its theoretical validity(AU)

Construction and verification of Lactococcus lactis NZ9000 genome-scale metabolic model / 生物工程学报

With the advent of the post-genomic era, metabolic engineering of microorganisms plays an increasingly important role in industrial production. The genome-scale metabolic model (GSMM) integrates all known metabolic information in the organism to provide an optimal platform for global understanding of the metabolic state of the organism and rational guidance for metabolic engineering. As a model strain, Lactococcus lactis NZ9000 plays an important role in industrial fermentation, but there is still no specific genome-scale metabolic model for it. Based on genomic function annotation and comparative genomics, we constructed the first genome-scale metabolic model iWK557 of L. lactis NZ9000, which contains 557 genes, 668 metabolites, and 840 reactions, and further verified at both qualitative and quantitative levels, to provide a good tool for rationally guiding metabolic engineering.

Dynamic Response and Damage Analysis of Human Head and Neck in Automobile Rear Impact / 医用生物力学

Objective To establish the precise finite element model of the head and neck based on human anatomical structure, so as to study neck injuries caused by rear impact at different speeds. Methods The model was based on CT scan images of the head and neck of human body. The Mimics software was used to reconstruct the three-dimensional (3D) bone, and the 3D solid ligaments, small joints and other tissues of the neck were improved and meshed by HyperMesh. The generated models included the head, 8 vertebrae (C1-T1), 6 intervertebral discs (annulus, nucleus pulposus and upper and lower cartilage endplates), facet joints (cartilage and joint capsule ligaments), ligaments, muscles, etc. Finally, the model verification and post-collision calculation were completed in the finite element post-processing software. Results The simulation results of the models under axial impact, front and back flexion and lateral flexion were compared with the experimental data to verify the effectiveness of the model. Then post-collision simulation at the speed of 20, 40, 60 and 80 km/h was conducted. At the speed of 20 km/h, there was no damage to the neck. At the speed of 40, 60 and 80 km/h, the ligament was the first to be damaged. As the speed increased, the stress on tissues of the neck increased continuously. At the speed of 80 km/h, the maximum stresses of the dense bone, cancellous bone and annulus of the cervical vertebrae were 226.4, 11.5, and 162.8 MPa, respectively. When the ligament strain reached the limit, tearing began to occur. Conclusions The finite element model of the head and neck established in this study has high bionics and effectiveness, and can be used for studying neck injury analysis in traffic accidents, which is helpful for the diagnosis, treatment and prevention of cervical spine injury to a certain extent.

External Validation of the ELAPSS Score for Prediction of Unruptured Intracranial Aneurysm Growth Risk / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: Prediction of intracranial aneurysm growth risk can assist physicians in planning of follow-up imaging of conservatively managed unruptured intracranial aneurysms. We therefore aimed to externally validate the ELAPSS (Earlier subarachnoid hemorrhage, aneurysm Location, Age, Population, aneurysm Size and Shape) score for prediction of the risk of unruptured intracranial aneurysm growth. METHODS: From 11 international cohorts of patients ≥18 years with ≥1 unruptured intracranial aneurysm and ≥6 months of radiological follow-up, we collected data on the predictors of the ELAPSS score, and calculated 3- and 5-year absolute growth risks according to the score. Model performance was assessed in terms of calibration (predicted versus observed risk) and discrimination (c-statistic). RESULTS: We included 1,072 patients with a total of 1,452 aneurysms. During 4,268 aneurysm-years of follow-up, 199 (14%) aneurysms enlarged. Calibration was comparable to that of the development cohort with the overall observed risks within the range of the expected risks. The c-statistic was 0.69 (95% confidence interval [CI], 0.64 to 0.73) at 3 years, compared to 0.72 (95% CI, 0.68 to 0.76) in the development cohort. At 5 years, the c-statistic was 0.68 (95% CI, 0.64 to 0.72), compared to 0.72 (95% CI, 0.68 to 0.75) in the development cohort. CONCLUSIONS: The ELAPSS score showed accurate calibration for 3- and 5-year risks of aneurysm growth and modest discrimination in our external validation cohort. This indicates that the score is externally valid and could assist patients and physicians in predicting growth of unruptured intracranial aneurysms and plan follow-up imaging accordingly.

Leaf area estimation from linear measurements in different ages of Crotalaria juncea plants

ABSTRACT The goal of this study was to estimate the leaf area of Crotalaria juncea according to the linear dimensions of leaves from different ages. Two experiments were conducted with C. juncea cultivar IAC-KR1, in the 2014/2015 sowing seasons. At 59, 82, 102, 129 days after sowing (DAS) of the first and 61, 80, 92, 104 DAS of the second experiment, 500 leaves were collected, totaling 4,000 leaves. In each leaf, the linear dimensions were measured (length, width, length/width ratio and length × width product) and the specific leaf area was determined through Digimizer and Sigma Scan Pro software, after scanning images. Then, 3,200 leaves were randomly separated to generate mathematical models of leaf area (Y) in function of linear dimension (x), and 800 leaves for the models validation. In C. juncea, the leaf areas determined by Digimizer and Sigma Scan Pro software are identical. The estimation models of leaf area as a function of length × width product showed superior adjustments to those obtained based on the evaluation of only one linear dimension. The linear model Ŷ=0.7390x (R2=0.9849) of the real leaf area (Y) as a function of length × width product (x) is adequate to estimate the C. juncea leaf area.

MODELO DE EDUCACIÓN AMBIENTAL NO FORMAL PARA LA PROTECCIÓN DE LOS HUMEDALES BAÑÓ Y LOS NEGROS / NON-FORMAL ENVIRONMENTAL EDUCATION MODEL FOR THE PROTECTION OF THE BAÑÓ AND LOS NEGROS WETLANDS

El propósito de este artículo fue generar y validar un modelo de educación ambiental no formal para la conservación con fines de protección de los humedales Bañó y Los Negros, ubicados en el bajo Sinú, entre los corregimientos de Cotocá Arriba, Castilleral y Palo de Agua, pertenecientes al área rural del municipio de Lorica, departamento de Córdoba, Colombia. Para ello, se definieron una serie de elementos constitutivos del modelo, entre éstos se señala el perfil ambiental del territorio obtenido a partir de un diagnóstico de la zona de estudio, la identificación de los factores que inciden en conductas negativas por parte de los habitantes de los humedales hacia este tipo de ecosistemas, además de la definición de una base pedagógica, partiendo de los elementos antes mencionados. Con base en la integración de los elementos se determinó el cuarto componente del modelo, es decir, los enfoques bajo los cuales se desarrollaría éste: sistémico, de desarrollo sostenible, interdisciplinario y comunitario; se buscó generar un modelo desde una visión holística, en la cual la comunidad fuera un actor fundamental en su implementación y contribuyera al desarrollo sostenible de los humedales, teniendo en cuenta la interdisciplinariedad como componente integrador. La materialización del modelo o su fase de validación se concretó en un programa educativo piloto de corte no formal que contó con una población beneficiada, metas y objetivos bien definidos, así como la identificación de los problemas a intervenir a partir del diagnóstico del territorio. Se estableció que los contenidos programáticos, metodología y herramientas pedagógicas dependerían de la definición de los componentes arriba indicados. Se propuso como un mecanismo de evaluación para el modelo y el programa piloto, derivado del mismo, la aplicación del ciclo PHVA (planear, hacer, verificar y actuar).

The main purpose of this article is to generate and to validate a non-formal environmental education model for the conservation and protection of the Bañó and Los Negros wetlands, located in the lower Sinú region, between the districts of Cotocá Arriba, Castilleral and Palo de Agua, within the rural areas of the municipality of Lorica, in the Department of Córdoba, Colombia. For this purpose, a series of constitutive elements of the model were defined including the environmental profile of the territory obtained from a diagnosis of the area of study, the factors impinging on negative behavior on the part of the wetlands inhabitants towards those types of ecosystems were defined, besides the definition of a pedagogical basis was drawn from the above mentioned elements. Based on the integration of those elements, the fourth component of the model was identified, this is to say, the approaches under which it would be developed were obtained: systemic, sustainable, interdisciplinary and community developed. A model was searched from a comprehensive vision in which the community was a fundamental actor in its implementation and contributed to the sustainable development of the wetlands considering interdisciplinarity as an integrating component. The materialization of the model or its validation phase was specified through a non-formal educational pilot program that counted with a benefited population, well defined goals and objectives, as well as the identification of the problems to be intervened, drawn from the diagnosis of the territory. It was established that the contents, methodology and pedagogic tools would depended upon the definition of the above-mentioned components. The PDCA (planning, doing, checking and acting) cycle was proposed as a mechanism for evaluating the model and the pilot program derived from it.

Establishment and validation of a dynamic finite element model of human head-neck / 医用生物力学

Objective To construct a three-dimensional (3D) dynamic head-neck finite element model which ac cords with the anatomical structure,and study its dynamic responses under the extemal force.Methods By using the neck CT images of a Chinese adult male volunteer and obtaining the 3D cervical point cloud data,the finite element model of cervical spine was established using ICEM-CFD and HyperMesh software.This model,including vertebrae,intervertebral discs,facet joints,ligaments and cartilage tissues,and combining with the es tablished and verified head finite element model,was assembled as human head-neck finite element model with detailed anatomical structures.Results The model was validated by data of head-neck axial impact experiments reported in previously published literature.The simulation results showed that the neck deformation,head acceleration,head force and injury positions were preferably consistent with the experimental data.Conclusions The established 3D dynamic finite element model can be used to study head-neck dynamic responses and damage mechanism in the fields of traffic safety and impact injuries.

Establishment and validation of a dynamic finite element model of human head-neck / 医用生物力学

Objective To construct a three-dimensional (3D) dynamic head-neck finite element model which accords with the anatomical structure, and study its dynamic responses under the external force. Methods By using the neck CT images of a Chinese adult male volunteer and obtaining the 3D cervical point cloud data, the finite element model of cervical spine was established using ICEM-CFD and HyperMesh software. This model, including vertebrae, intervertebral discs, facet joints, ligaments and cartilage tissues, and combining with the established and verified head finite element model, was assembled as human head-neck finite element model with detailed anatomical structures. Results The model was validated by data of head-neck axial impact experiments reported in previously published literature. The simulation results showed that the neck deformation, head acceleration, head force and injury positions were preferably consistent with the experimental data. Conclusions The established 3D dynamic finite element model can be used to study head-neck dynamic responses and damage mechanism in the fields of traffic safety and impact injuries.

Model validation and evaluation of developmental toxicity of five drugs using zebrafish embryos / 中国药理学通报

Aim To explore the toxicity and safety of five kinds of known positive drugs, cyclophosphamide, acetyl salicylic acid, tetracycline hydrochloride, dexa-methasone acetate and azacitidine, using zebrafish em-bryos. Methods We selected normally developed 4 hpf zygote, and used water bath infecting method to add the drug to the artificial seawater. Each drug had five concentrating groups, a separate control group and solvent control group. We observed the dead zebrafish embryos after 120 hpf drugs, counted the number of deaths and deformities of zebrafish embryos, and cal-culated mortality abnormal rate, the median lethal con-centration (LC50 ), concentration for 50% of maximal effect (EC50 ), therapeutic index (TI) under 120 hpf condition. We also used the formula TI = LC50 / EC50 to calculate positive drug therapeutic index. Based on measured LC50 we calculated most nonlethal concentra-tion (MNLC) of each drug setting, namely 1 / 10 MN-LC, 1 / 3 MNLC, MNLC,LC10 four concentration, tha-lidomide as a positive control, vitamin C as a negative control, artificial seawater as control, 0. 5% DMSO as solvent control. Put in 28. 5 ℃ environment for 120 hours,embryo development was observed daily for de-velopmental state,mortality,deforming rate and abnor-mal condition. Results The result of five drugs LC50 in descending order: cyclophosphamide > azacitidine> tetracycline hydrochloride > acetylsalicylic acid >dexamethasone acetate. EC50 in descending order: cy-clophosphamide > tetracycline hydrochloride > azaciti-dine > acetylsalicylic acid > dexamethasone acetate. The TI values of cyclophosphamide, acetyl salicylic acid, tetracycline hydrochloride, dexamethasone ace-tate, azacitidine were 1. 92, 1. 11, 1. 05, 1. 44, 2. 99, respectively. Conclusion Zebrafish embryo model can be used in the preliminary evaluation of drugs, and the study of early developmental toxicity and safety.

The simulation analysis on biomechanical responses of human head under different loading conditions / 医用生物力学

Objective To construct a three-dimensional finite element model of human skull with anatomic structure and to study biomechanical responses of the head under various loading conditions. Methods The finite element model of high-precision human head with anatomic structure was reconstructed with the constitutive skull made from elastic-plastic material to simulate the fracture. This model was used to simulate frontal impact intracranial pressure testing, dynamic skull fracture testing and head drop testing reported by the literature, and the simulation reproduced the experimental process of head subjected to impact loads, skull fractures, and biomechanical responses of head fall at different speed. Results Under frontal impact loading, the model showed hedge-side positive-negative intracranial pressure distributions, and the occipital deformation was more serious than that in prefrontal, parietal under similar loading. The faster falling speed would cause more serious injuries. Conclusions To establish the accurate anatomic finite element model of human head can preferably simulate biomechanical responses of the head under the loading of impact and fall. Through quantifying parameters such as contact force and intracranial pressure, injury risks can be assessed to provide scientific references for design of protective devices.

Development and validation for the finite element model of child head / 医用生物力学

Objective To investigate brain responses from children during traffic accident and drop impact by developing a 3-year-old child head finite element (FE) model. Methods Based on the CT data from a 4-year-old child head, the FE child head model with detaile