Resumen: Antecedentes: Mediante un meta-análisis de tres niveles, el objetivo de esta investigación fue examinar la relación entre la participación de los padres en los deberes escolares y el rendimiento académico de los estudiantes, así como estudiar el rol mediador en esta relación de ciertas variables que podrían haber estado relacionadas con algunos resultados inconsistentes en estudios primarios. Método: Se identificaron 28 estudios, con 252 tamaños del efecto, para un total de 378222 participantes. Resultados: Los resultados revelaron una débil relación negativa entre la implicación de los padres en los deberes y el rendimiento de los estudiantes (r = −0,064, p < 0,001). Esta relación fue moderada por el tipo de implicación parental. Específicamente, el rendimiento de los estudiantes se relacionó positivamente con el apoyo a la autonomía, pero no con el apoyo al contenido, el control de los padres, la frecuencia y la combinación de estas dimensiones. Además, dicha relación fue moderada por la medida de rendimiento, el curso de los estudiantes y el género de los padres. Conclusiones: Es necesaria más investigación cualitativa sobre lo que ocurre en torno a las interacciones entre padres e hijos a la hora de la realización de los deberes escolares.

Abstract: Background: Applying a three-level meta-analysis, the goal of our investigation was to examine the relationship between parental homework involvement and students' achievement, and to investigate whether certain study features could have resulted in the inconsistent results relating to this relationship from prior studies. Method: We identified a total of 28 studies (32 independent samples) with 252 effect sizes for a total of 378222 participants. Results: Our meta-analysis revealed an overall weak negative relationship between parental homework involvement and students' achievement (r = −0.064, p < .001). The overall relationship was moderated by the dimension of parental homework involvement. Specifically, students' achievement was positively related to autonomy support, but largely unrelated to content support, parental control, frequency, and mixed. Additionally, the overall relationship was moderated by achievement measure, grade level, and parent gender. Conclusions: Given that parental autonomy support was the only dimension that was positively related to students' achievement, it would be important to conduct qualitative research that provides longitudinal descriptions of parent-child interactions relating to homework tasks as children make their transition from elementary to middle and high school.

ABSTRACT Hypothesis: Nomogram can be built to predict the pathological T3a upstaging from clinical T1a in patients with localized renal cell carcinoma before surgery. Purpose: Renal cell carcinoma (RCC) patients with clinical T1a (cT1a) disease who are upstaged to pathological T3a (pT3a) have reduced survivals after partial nephrectomy. We aimed to develop a nomogram-based model predicting pT3a upstaging in RCC patients with preoperative cT1a based on multiple preoperative blood indexes and oncological characteristics. Materials and Methods: Between 2010 and 2019, 510 patients with cT1a RCC were individually matched according to pT3a upstaging and pathological T1a (pT1a) at a 1:4 ratio using clinicopathologic features. Least absolute shrinkage and selection operator regression analysis was used to identify the most important risk factor from 40 peripheral blood indicators, and a predictive model was established. Multivariate logistic regression analysis was performed with the screened blood parameters and clinical data to identify significant variables. Harrell’s concordance index (C-index) was applied to evaluate the accuracy of the model for predicting pT3a upstaging in patients with cT1a RCC. Results: Out of 40 blood indexes, the top ranked predictor was fibrinogen (FIB). Age, the ratio of the tumor maximum and minimum diameter (ROD), FIB, and tumor size were all independent risk factors for pT3a upstaging in multivariate analysis. A predictive ARFS model (Age, ROD, FIB, tumor Size) was established, and the C-index was 0.756 (95% CI, 0.681-0.831) and 0.712 (95% CI, 0.638-0.785) in the training and validation cohorts, respectively. Conclusions: Older age, higher ROD, increased FIB level, and larger tumor size were independent risk factors for upstaging. The ARFS model has a high prediction efficiency for pT3a upstaging in patients with cT1a RCC.

RESUMO Objetivos Avaliar o potencial da aplicação da tecnologia de impressão 3D na medição da área de defeito ósseo acetabular em pacientes adultos diagnosticados com displasia do desenvolvimento do quadril (DDH). Métodos 23 casos de DDH que requereram cirurgia de substituição total do quadril foram incluídos neste estudo. O exame pré-operatório confirmou os filmes pélvicos padrão Crowe, incluindo 3 casos de Crowe I, 7 Crowe II, e 13 Crowe III. A tecnologia de impressão 3D foi utilizada para imprimir o modelo de quadril antes da operação. Com base no modelo pré-impresso, o planejamento pré-operatório e os procedimentos cirúrgicos foram estabelecidos. A área dos defeitos ósseos acetabulares foi medida, a prótese de tamanho selecionado foi registrada, e a cirurgia foi realizada (grupo A). A área do defeito ósseo acetabular real e o tamanho da prótese também foram registrados (grupo B). Resultados Os resultados comparativos indicaram que a área real do defeito acetabular medida intraoperativamente e a área medida usando a tecnologia de impressão 3D não diferiu significativamente para todos os participantes (todos P>0,05). Conclusão O modelo pré-operatório pode medir com precisão a área de defeito ósseo acetabular para DDH. É relevante desenvolver implantes individualizados para pacientes com DDH tratados com a técnica de impressão 3D. Nível de Evidência IV: Série de casos.

ABSTRACT Objectives Evaluate the application value of 3D printing technology in measuring acetabular bone defect area in adult patients diagnosed with developmental dysplasia of the hip (DDH). Methods 23 cases of DDH requiring total hip replacement surgery were enrolled in this study. Preoperative examination confirmed the standard pelvic plain films Crowe, including 3 cases of Crowe I, 7 Crowe II, and 13 Crowe III. The 3D printing technology was used to print the hip model before the operation. Based on the pre-printed model, pre-operative planning and surgical procedures were established. The area of the acetabular bone defects was measured, the selected size prosthesis was recorded, and the surgery was performed (group A). The actual acetabular bone defect area and the prosthesis size were also recorded (group B). Results The comparative results indicated that the actual acetabular defect area measured intraoperatively and the area measured using the 3D printing technology did not significantly differ for all participants (all P>0.05). Conclusion Preoperative model can accurately measure the acetabular bone defect area for DDH. It is significant to develop individualized implants for DDH patients treated with the 3D printing technique. Level of Evidence IV: Case series.

Abstract Shielded metal arc butt welded joints for 9%Ni steel using nickel-based filler metal were analyzed by optical microscopy, scanning electron microscope, as well as transmission electron microscopy. The nanoindentation method was used to study the correlation between the structure and micromechanical properties of the fusion welded joint. The results show that there is a microstructural evolution from melted deposit to 9%Ni base steel. A significant coarse lath martensite-bainite mixture has been obtained in 9%Ni steel close to the fusion boundary while the retained austenite distributing in grain boundary of lath martensite has reduced to an undetectable level. In fusion boundary, an intermetallic layer has been observed which corresponds to the epitaxial growth of weld metal. The analysis of stress-strain behavior using nanoindentation shows that the heat-affected zone of coarse grains exhibits ductility loss and quantitative plastic deformation failure. The fusion boundary has the lowest value of yield stress while the coarse grained heat affected zone has the maximum value of yield stress.

Resumo Fundamento A doença arterial coronariana (DAC) associada à quimioterapia está se tornando um tema emergente na prática clínica. Contudo, o mecanismo subjacente da quimioterapia associada à DAC permanence incerto. Objetivos O estudo investigou a associação entre a quimioterapia e as anomalias anatômicas ateroscleróticas das artérias coronárias dentre pacientes com cancer de pulmão. Métodos Foram incluídos pacientes submetidos à angiografia coronária (AGC), entre 2010 e 2017, com câncer de pulmão prévio. Os fatores de risco associados à DAC e os dados sobre o câncer de pulmão foram avaliados. Avaliamos as anomalias das artérias coronárias de acordo com o escore SYNTAX (SXescore) calculado à AGC. Na análise de regressão logística, o escore SYNTAX foi classificado como alto (SXescoreALTO) se ≥22. Os dados foram analisados através de estatística descritiva e análise de regressão. Resultados Ao todo, 94 pacientes foram incluídos no estudo. O SXescore foi mais alto no grupo com quimioterapia quando comparado com o grupo sem quimioterapia (25,25, IIQ [4,50–30,00] versus 16,50, IIQ [5,00–22,00]; p = 0,0195). A taxa do SXescoreALTO foi maior no grupo com quimioterapia do que no no grupo sem quimioterapia (58,33% versus 25,86; p = 0,0016). Tanto a análise de regressão logística univariada (OR: 4,013; 95% IC:1,655–9,731) quanto a multivariada (OR: 5,868; 95% IC:1,778–19,367) revelaram que a quimioterapia aumentou o risco de uma maior taxa do SXescoreALTO. A análise multivariada de regressão logística Stepwise mostrou que o risco para DAC anatômica mais grave aumenta com a quimioterapia como um todo em 5.323 vezes (95% IC: 2,002–14,152), e com o regime à base de platina em 5,850 vezes (95% IC: 2,027–16,879). Conclusões A quimioterapia está associada com a complexidade e gravidade anatômica da DAC, o que pode explicar, em parte, o maior risco de DAC associada à quimioterapia dentre pacientes com câncer de pulmão. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)

Abstract Background Chemotherapy-related coronary artery disease (CAD) is becoming an emerging issue in clinic. However, the underlying mechanism of chemotherapy-related CAD remains unclear. Objective The study investigated the association between chemotherapy and atherosclerotic anatomical abnormalities of coronary arteries among lung cancer patients. Methods Patients undergoing coronary angiography (CAG) between 2010 and 2017, who previously had lung cancer, were examined. Risk factors associated with CAD and information about lung cancer were evaluated. We assessed coronary-artery abnormalities by SYNTAX score (SXscore) based on CAG. In logistic-regression analysis, we defined high SXscore (SXhigh) grade as positive if ≥22. Data were analyzed through descriptive statistics and regression analysis. Results A total of 94 patients were included in the study. The SXscore was higher in the chemotherapy group than in the non-chemotherapy group (25.25, IQR [4.50–30.00] vs. 16.50, IQR [ 5.00–22.00], p = 0.0195). The SXhigh rate was greater in the chemotherapy group than in the non-chemotherapy group (58.33% vs. 25.86; p = 0.0016). Both univariate (OR:4.013; 95% CI:1.655–9.731) and multivariate (OR:5.868; 95% CI:1.778–19.367) logistic-regression analysis revealed that chemotherapy increased the risk of greater SXhigh rates. Multivariate stepwise logistic-regression analysis showed the risk of more severe anatomical CAD is increased by chemotherapy as a whole by 5.323 times (95% CI: 2.002–14.152), and by platinum-based regimens by 5.850 times (95% CI: 2.027–16.879). Conclusions Chemotherapy is associated with anatomical complexity and severity of CAD, which might partly account for the higher risk of chemotherapy-related CAD among lung cancer patients. (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0)

SUMMARY: This study aimed to investigate the sagittal spinal-pelvic morphological changes, as well as the relationship between pelvic anatomical changes and the spinal-pelvic plane in patients with adolescent idiopathic scoliosis (AIS), in order to provide guidelines for orthopedic surgery in AIS. X-ray data were collected for retrospective analysis from 30 patients diagnosed as AIS in the Departments of Radiology at the Second Affiliated Hospital of Inner Mongolia Medical University and the Inner Mongolia International Mongolian Medical Hospital from April 2014 to November 2018, along with 30 normal adolescents as control. Pelvic parameters, including pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS), a spinal parameter, lumbar lordosis (LL), and anatomical parameters, including sacral width (SW) and femoral head- sacrum distance (FH-S), were measured. The spinal-pelvic parameters were compared between AIS patients and normal controls and also between male and female AIS patients. Pearson correlation was performed to analyze correlation between spinal-pelvic parameters and between spinal-pelvic parameters and anatomical parameters in both AIS patients and normal controls. PT was significantly lower in AIS patients than in normal controls (P < 0.05), whereas no significant difference was found in the other spinal-pelvic parameters, i. e. , LL, PI, and SS. There was a significant difference in PT between sexes in AIS patients. SS was significantly correlated with LL in EIA patients (P < 0.05, r > 0.5). SS was significantly correlated with LL and PI, and PT with LL, PI, and SS in normal controls (all P < 0.05), and there was no significant correlation between the other sagittal spinal-pelvic parameters (P > 0.05). FH-S was significantly correlated with LL, PI, SS, and PT in AIS patients (all P < 0.05). AIS affects some of the sagittal spinalpelvic parameters and anatomical parameters. In AIS, there is a significant correlation between the spinal-pelvic parameters, and the anatomical parameter is significantly correlated with multiple spinal-pelvic parameters.

RESUMEN: Este estudio tuvo como objetivo investigar los cambios morfológicos sagitales de la columna vertebral-pélvica, así como la relación entre los cambios anatómicos pélvicos y el plano espinal-pélvico en pacientes con escoliosis idiopática adolescente (EIA), con el fin de proporcionar pautas para la cirugía ortopédica en AIS. Se obtuvieron los datos de rayos X para el análisis retrospectivo de 30 pacientes diagnosticados como EIA en los Departamentos de Radiología del hospital Second Affiliated Hospital of Inner Mongolia Medical University y el hospital Inner Mongolia International Mongolian Medical Hospital, desde abril de 2014 hasta noviembre del 2018, junto con 30 adolescentes normales como control. Se midieron los parámetros pélvicos, que incluyeron incidencia pélvica (IP), inclinación pélvica (P) y pendiente sacra (PS), un parámetro espinal, lordosis lumbar (LL) y parámetros anatómicos, que incluyeron el ancho sacro (AS) y la distancia del sacro cabeza femoral (FH-S). Los parámetros espinalpélvicos se compararon entre los pacientes con EIA y los controles normales, como también entre pacientes con EIA masculinos y femeninos. La correlación de Pearson se realizó para analizar la correlación entre los parámetros espinal-pélvicos y entre los parámetros espinal-pélvicos y los parámetros anatómicos tanto en pacientes con EIA como en controles normales. PT fue significativamente menor en pacientes con EIA que en los controles normales (P <0,05), mientras que no se encontraron diferencias significativas en los otros parámetros espinal-pélvicos, i. mi. , LL, PI y SS. Hubo una diferencia significativa en PT en pacientes de ambos sexos con EIA. SS se correlacionó significativamente con LL en pacientes con EIA (P <0,05, r> 0,5). SS se correlacionó significativamente con LL y PI, y PT con LL, PI y SS en controles normales (todos P <0,05), y no hubo correlación significativa entre los otros parámetros sagitales de la columna vertebral-pélvica (P> 0,05) FH-S se correlacionó significativamente con LL, PI, SS y PT en pacientes con EIA (todos P <0,05). EIA afecta algunos de los parámetros sagitales de la columna vertebral-pélvica y los parámetros anatómicos. En EIA, existe una correlación significativa entre los parámetros espinal-pélvicos, y el parámetro anatómico se correlaciona significativamente con múltiples parámetros espinales-pélvicos.

OBJECTIVES: To evaluate the safety and efficacy of a novel bone cement-injectable cannulated pedicle screw augmented with polymethylmethacrylate in osteoporotic spinal surgery. METHODS: This study included 128 patients with osteoporosis (BMD T-score −3.2±1.9; range, −5.4 to -2.5) who underwent spinal decompression and instrumentation with a polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screw. Postoperative Visual Analogue Scale scores and the Oswestry Disability Index were compared with preoperative values. Postoperative plain radiographs and computed tomography (CT) scans were performed immediately after surgery; at 1, 3, 6, and 12 months; and annually thereafter. RESULTS: The mean follow-up time was 42.4±13.4 months (range, 23 to 71 months). A total of 418 polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screws were used. Cement extravasations were detected in 27 bone cement-injectable cannulated pedicle screws (6.46%), mainly in cases of vertebral fracture, without any clinical sequela. The postoperative low back and lower limb Visual Analogue Scale scores were significantly reduced compared with the preoperative scores (<0.01), and similar results were noted for the Oswestry Disability Index score (p<0.01). No significant screw migration was noted at the final follow-up relative to immediately after surgery (p<0.01). All cases achieved successful bone fusion, and no case required revision. No infection or blood clots occurred after surgery. CONCLUSIONS: The polymethylmethacrylate-augmented bone cement-injectable cannulated pedicle screw is safe and effective for use in osteoporotic patients who require spinal instrumentation.

Effects of various rare-earth elements (RE: Gd, Nd and Ce) additions on microstructures and mechanical properties of ultra-light dual phase Mg-9Li-0.4Zr alloy were investigated. The results indicated that Mg-9Li-5RE-0.4Zr alloys exhibited α-Mg, β-Li and RE-containing intermetallic compound structures. 5 wt.% Gd, Nd and Ce additions enhanced the strength properties of as-extruded Mg-9Li-0.4Zr alloy, but greatly deteriorated the ductility. The final mechanical properties of Mg-9Li-5RE-0.4Zr alloys were 161MPa∼167MPa in ultimate strength, 141MPa∼156MPa in yield strength and 20.8%∼32.5% in elongation. Heat treatment was hardly able to improve the mechanical properties for Mg-9Li-5RE-0.4Zr alloys.

OBJECTIVES: To describe a new approach for the application of polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws. METHODS: Between June 2010 and February 2013, 43 patients with degenerative spinal disease and osteoporosis (T-score <-2.5) underwent lumbar fusion using cement-injectable cannulated pedicle screws. Clinical outcomes were evaluated using a Visual Analog Scale and the Oswestry Disability Index. Patients were given radiographic follow-up examinations after 3, 6, and 12 months and once per year thereafter. RESULTS: All patients were followed for a mean of 15.7±5.6 months (range, 6 to 35 months). The Visual Analog Scale and Oswestry Disability Index scores showed a significant reduction in back pain (p = 0.018) and an improvement in lower extremity function (p = 0.025) in patients who underwent lumbar fusion using the novel screw. Intraoperative cement leakage occurred in four patients, but no neurological complications were observed. Radiological observation indicated no loosening or pulling out of the novel screw, and bone fusion was excellent. CONCLUSIONS: The described polymethylmethacrylate augmentation technique using bone cement-injectable cannulated pedicle screws can reduce pain and improve spinal dysfunction in osteoporotic patients undergoing osteoporotic spine surgery.

OBJECTIVES: To explore the microendoscopic discectomy technique and inclusion criteria for the treatment of recurrent lumbar disc herniation and to supply feasible criteria and technical notes to avoid complications and to increase the therapeutic effect. METHODS: A consecutive series of 25 patients who underwent posterior microendoscopic discectomy for recurrent lumbar disc herniation were included. The inclusion criteria were as follows: no severe pain in the lumbar region, no lumbar instability observed by flexion-extension radiography and no intervertebral discitis or endplate damage observed by magnetic resonance imaging. All patients were diagnosed by clinical manifestations and imaging examinations. RESULTS: Follow-up visits were carried out in all cases. Complications, such as nerve injuries, were not observed. The follow-up outcomes were graded using the MacNab criteria. A grade of excellent was given to 12 patients, good to 12 patients and fair to 1 patient. A grade of excellent or good occurred in 96% of cases. One patient relapsed 3 months after surgery and then underwent lumbar interbody fusion and inner fixation. The numerical rating scale of preoperative leg pain was 7.4± 1.5, whereas it decreased to 2.1±0.8 at 7 days after surgery. The preoperative Oswestry disability index of lumbar function was 57.5±10.0, whereas it was 26.0±8.5 at 7 days after surgery. CONCLUSION: In these cases, microendoscopic discectomy was able to achieve satisfactory clinical results. Furthermore, it has advantages over other methods because of its smaller incision, reduced bleeding and more efficient recovery.