1,123 research outputs found
Pancreatic and hepatobiliary cancers: Problems in staging of pancreatic and hepatobiliary tumours
The sitting vs standing spine
Background
Planning of surgical procedures for spinal fusion is performed on standing radiographs, neglecting the fact that patients are mostly in the sitting position during daily life. The awareness about the differences in the standing and sitting configuration of the spine has increased during the last years. The purpose was to provide an overview of studies related to seated imaging for spinal fusion surgery, identify knowledge gaps and evaluate future research questions.
Methods
A literature search according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) extension for Scoping Reviews (PRISMASc) was performed to identify reports related to seated imaging for spinal deformity surgery. A summary of the finding is presented for healthy individuals as well as patients with a spinal disorder and/or surgery.
Results
The systematic search identified 30 original studies reporting on 1) the pre- and postoperative use of seated imaging of the spine (n=12), 2) seated imaging of the spine for non - surgical evaluation (n=7) and 3) seated imaging of the spine among healthy individuals (12). The summarized evidence illuminates that sitting leads to a straightening of the spine decreasing thoracic kyphosis (TK), lumbar lordosis (LL), the sacral slope (SS). Further, the postural change between standing and sitting is more significant on the lower segments of the spine. Also, the adjacent segment compensates the needed postural change of the lumbar spine while sitting with hyperkyphosis.
Conclusions
The spine has a different configuration in standing and sitting. This systematic review summarizes the current knowledge about such differences and reveals that there is minimal evidence about their consideration for surgical planning of spinal fusion surgery. Further, it identifies gaps in knowledge and areas of further research
Computational investigation of the haemodynamics shows criticalities of central venous lines used for chronic haemodialysis in children
Background: Haemodialysis is a life-saving treatment for children with kidney failure. The majority of children have haemodialysis through central venous lines (CVLs). The use of CVLs in pediatric patients is often associated to complications which can lead to their replacement. The aim of this study is to investigate haemodynamics of pediatric CVLs to highlight the criticalities of different line designs. Methods: Four models of CVLs for pediatric use were included in this study. The selected devices varied in terms of design and sizes (from 6.5 Fr to 14 Fr). Accurate 3D models of CVLs were reconstructed from high-resolution images including venous and arterial lumens, tips and side holes. Computational fluid dynamics (CFD) analyses were carried out to simulate pediatric working conditions of CVLs in ideal and anatomically relevant conditions. Results: The arterial lumens of all tested CVLs showed the most critical conditions with the majority of blood flowing through the side-holes. A zone of low flow was identified at the lines' tip. The highest shear stresses distribution (>10 Pa) was found in the 8 Fr line while the highest platelet lysis index in the 10 Fr model. The analysis on the anatomical geometry showed an increase in wall shear stress measured in the 10 F model compared to the idealised configuration. Similarly, in anatomical models an increased disturbance and velocity of the flow was found inside the vein after line placement. Conclusion: This study provided a numerical characterization of fluid dynamics in pediatric CVLs highlighting performance criticalities (i.e. high shear stresses and areas of stagnation) associated to specific sizes (8 Fr and 10 Fr) and conditions (i.e. anatomical test)
Strong additive effect of 1,25-dihydroxycholecalciferol and cyclosporine A but not tacrolimus in rat lung allotransplantation
Objectives: 1,25-Dihydroxycholecalciferol (calcitriol, vitamin D3) has immunosuppressive properties. This study evaluates the effect of calcitriol in combination with either cyclosporine A or tacrolimus on acute lung allograft rejection in a rat model of unilateral left lung allotransplantation. Methods: Unilateral left lung transplantation was performed in male rats (Brown-Norway to Fischer F344, 200-250 g body weight). For immunosuppression, the following subtherapeutic doses were used: calcitriol 0.5 μg/kg/day, cyclosporine A 2.5 mg/kg/day i.p., and tacrolimus 40 μg/kg i.m. Five groups (n=5) were analyzed: cyclosporine A; cyclosporine A and calcitriol; calcitriol; tacrolimus and calcitriol; and tacrolimus. The injections were performed for 5 days starting from the day of transplantation. Recipients were sacrificed on day 5 post-transplant. The contralateral right main bronchus and pulmonary artery were occluded for 5 min and blood was drawn for blood gas analysis. The grafts were excised, fixed in formaline and embedded in paraffin. Histological evaluation was done in blinded fashion (ISHLT 1999/rank scale). The mean and standard error of the mean (PaO2) or the median and range (rejection grading) are given. ANOVA followed by planned comparison for the PaO2 and Kruskal-Wallis ANOVA for rejection grading were applied, p<0.05 considered significant. Results: Arterial PaO2 on day 5 was very low in animals treated with subtherapeutic dosages of either cyclosporine A (48±10 mmHg), calcitriol (51±3) or tacrolimus (86±22). Combined treatment with cyclosporine A and calcitriol revealed a significant improvement (248±78; p<0.05 vs. other groups), whereas the combination of tacrolimus with calcitriol did not reveal any benefit (65±9). Rejection grading with these subtherapeutic doses did not show any significant difference between groups. Conclusions: Our data indicate that cyclosporine A, but not tacrolimus, has a strong additive effect with calcitriol on acute rat lung allograft rejectio
Impact of a dry granular flow against a rigid wall: MPM simulations with a new constitutive approach
The dynamic interaction between granular flowing masses and obstacles is a very complex phenomenon involving large displacements and high strain rates. To simulate the event in a continuum-based framework both advanced numerical tools and constitutive relationships are required. In this work, the impact of a dry granular mass against a rigid wall is numerically simulated using the open-source Material Point Method code ANURA3D, while the constitutive model proposed by Marveggio et al., 2021 is adopted for the granular mass. The model accounts for rate and grain packing dependence, which have been shown to be crucial to reproduce the propagation of compression and rarefaction waves inside the mass. The model is capable of reproducing “solidification” and “liquefaction” phenomena observed in the DEM impact tests results already available in the literature
Rapid recognition of drug-resistance/sensitivity in leukemic cells by Fourier transform infrared microspectroscopy and unsupervised hierarchical cluster analysis
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Análise morfométrica do endotélio coreano de tartaruga (Trachemis scripta) à microscopia eletrônica de varredura.
UV-C irradiation is highly effective in inactivating SARS-CoV-2 replication
The potential virucidal effects of UV-C irradiation on SARS-CoV-2 were experimentally evaluated for different illumination doses and virus concentrations (1000, 5, 0.05 MOI). At a virus density comparable to that observed in SARS-CoV-2 infection, an UV-C dose of just 3.7 mJ/cm2 was sufficient to achieve a more than 3-log inactivation without any sign of viral replication. Moreover, a complete inactivation at all viral concentrations was observed with 16.9 mJ/cm2. These results could explain the epidemiological trends of COVID-19 and are important for the development of novel sterilizing methods to contain SARS-CoV-2 infection
Traian and the Danubian Provinces. The political, economic and religious life in the Danubian Provinces: Proceedings of the 4th International Conference on the Roman Danubian Provinces, Zagreb, 15th - 17th November 2017.
The “Department of Archaeology“ of the Faculty of Humanities and Social Sciences of the University of Zagreb gladly hosted the 4th International Conference on the Roman Danubian Provinces in 2017. The Conference was organized with the support of the Faculty of Humanities and Social Sciences of the University of Zagreb, the Croatian Archaeological Society, and the Croatian Science Foundation through the project 6505 Between the Danube and the Mediterranean. Exploring the role of Roman military in the mobility of people and goods in Croatia during the Roman Era. Since it was organized in Zagreb, the Conference remained in Pannonia, not far from Siscia, the capital of Pannonia Savia, and in the territory of the Res publica Andautoniensium. The main topic of the Conference was Traian and the Roman Danubian Provinces or, more specifically, the political, economic and religious life in the Danubian Provinces.(from the Foreword)The “Department of Archaeology“ of the Faculty of Humanities and Social Sciences of the University of Zagreb gladly hosted the 4th International Conference on the Roman Danubian Provinces in 2017. The Conference was organized with the support of the Faculty of Humanities and Social Sciences of the University of Zagreb, the Croatian Archaeological Society, and the Croatian Science Foundation through the project 6505 Between the Danube and the Mediterranean. Exploring the role of Roman military in the mobility of people and goods in Croatia during the Roman Era. Since it was organized in Zagreb, the Conference remained in Pannonia, not far from Siscia, the capital of Pannonia Savia, and in the territory of the Res publica Andautoniensium. The main topic of the Conference was Traian and the Roman Danubian Provinces or, more specifically, the political, economic and religious life in the Danubian Provinces.(from the Foreword
Traian and the Danubian Provinces. The political, economic and religious life in the Danubian Provinces: Proceedings of the 4th International Conference on the Roman Danubian Provinces, Zagreb, 15th - 17th November 2017.
The “Department of Archaeology“ of the Faculty of Humanities and Social Sciences of the University of Zagreb gladly hosted the 4th International Conference on the Roman Danubian Provinces in 2017. The Conference was organized with the support of the Faculty of Humanities and Social Sciences of the University of Zagreb, the Croatian Archaeological Society, and the Croatian Science Foundation through the project 6505 Between the Danube and the Mediterranean. Exploring the role of Roman military in the mobility of people and goods in Croatia during the Roman Era. Since it was organized in Zagreb, the Conference remained in Pannonia, not far from Siscia, the capital of Pannonia Savia, and in the territory of the Res publica Andautoniensium. The main topic of the Conference was Traian and the Roman Danubian Provinces or, more specifically, the political, economic and religious life in the Danubian Provinces.(from the Foreword)The “Department of Archaeology“ of the Faculty of Humanities and Social Sciences of the University of Zagreb gladly hosted the 4th International Conference on the Roman Danubian Provinces in 2017. The Conference was organized with the support of the Faculty of Humanities and Social Sciences of the University of Zagreb, the Croatian Archaeological Society, and the Croatian Science Foundation through the project 6505 Between the Danube and the Mediterranean. Exploring the role of Roman military in the mobility of people and goods in Croatia during the Roman Era. Since it was organized in Zagreb, the Conference remained in Pannonia, not far from Siscia, the capital of Pannonia Savia, and in the territory of the Res publica Andautoniensium. The main topic of the Conference was Traian and the Roman Danubian Provinces or, more specifically, the political, economic and religious life in the Danubian Provinces.(from the Foreword
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