Manufacturing and Characterization of Hybrid Bulk Voxelated Biomaterials Printed by Digital Anatomy 3D Printing

The advent of 3D digital printers has led to the evolution of realistic anatomical organ shaped structures that are being currently used as experimental models for rehearsing and preparing complex surgical procedures by clinicians. However, the actual material properties are still far from being ideal, which necessitates the need to develop new materials and processing techniques for the next generation of 3D printers optimized for clinical applications. Recently, the voxelated soft matter technique has been introduced to provide a much broader range of materials and a profile much more like the actual organ that can be designed and fabricated voxel by voxel with high precision. For the practical applications of 3D voxelated materials, it is crucial to develop the novel high precision material manufacturing and characterization technique to control the mechanical properties that can be difficult using the conventional methods due to the complexity and the size of the combination of materials. Here we propose the non-destructive ultrasound effective density and bulk modulus imaging to evaluate 3D voxelated materials printed by J750 Digital Anatomy 3D Printer of Stratasys. Our method provides the design map of voxelated materials and substantially broadens the applications of 3D digital printing in the clinical research area.

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Recent Advances in the Development of Exogenous dsRNA for the Induction of RNA Interference in Cancer Therapy

Molecules ◽

10.3390/molecules26030701 ◽

2021 ◽

Vol 26 (3) ◽

pp. 701

Author(s):

Tatiana S. Golubeva ◽

Viktoria A. Cherenko ◽

Konstantin E. Orishchenko

Keyword(s):

Gene Expression ◽

Rna Interference ◽

Molecular Biology ◽

Gene Silencing ◽

Regulation Of Gene Expression ◽

Research Area ◽

Disease Treatment ◽

Practical Applications ◽

Agricultural Plants ◽

Insect Reproduction

Selective regulation of gene expression by means of RNA interference has revolutionized molecular biology. This approach is not only used in fundamental studies on the roles of particular genes in the functioning of various organisms, but also possesses practical applications. A variety of methods are being developed based on gene silencing using dsRNA—for protecting agricultural plants from various pathogens, controlling insect reproduction, and therapeutic techniques related to the oncological disease treatment. One of the main problems in this research area is the successful delivery of exogenous dsRNA into cells, as this can be greatly affected by the localization or origin of tumor. This overview is dedicated to describing the latest advances in the development of various transport agents for the delivery of dsRNA fragments for gene silencing, with an emphasis on cancer treatment.

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Effects of a sudden increase in natural mortality of adults on a population of the common snapping turtle (Chelydra serpentina)

Canadian Journal of Zoology ◽

10.1139/z91-185 ◽

1991 ◽

Vol 69 (5) ◽

pp. 1314-1320 ◽

Cited By ~ 120

Author(s):

Ronald J. Brooks ◽

Gregory P. Brown ◽

David A. Galbraith

Keyword(s):

Clutch Size ◽

Research Area ◽

Effective Density ◽

Egg Mass ◽

Sudden Increase ◽

Chelydra Serpentina ◽

Density Dependent ◽

Snapping Turtles ◽

The Mean ◽

Clutch Mass

A northern population of snapping turtles (Chelydra serpentina) centred around Lake Sasajewun in the Wildlife Research Area in Algonquin Park, Ontario, has been studied and individually marked since 1972. From 1972 to 1985, annual mortality and survivorship of adult females had been estimated at 1 and 96.6%, respectively, and only six dead turtles were found. Lake Sasajewun's population of C. serpentina was estimated in 1978–1979 and 1984–1985 at 38 and 47 adults, respectively. From 1976 to 1987, total number of nests found in the study area remained fairly constant and there were no significant changes in mean clutch size, mean clutch mass, or mean egg mass. On the main nest site, recruitment from 1976 to 1987 was 1.15 (1.8%) new females per year. From 1987 to 1989, we found 34 dead adult snapping turtles in the Wildlife Research Area. Observations of freshly dead animals indicated that most were killed by otters (Lutra canadensis) during the turtles' winter hibernation. A few uninjured turtles also died of septicemia in early spring shortly after emerging from hibernation. The estimated number of adults in Lake Sasajewun was 31 in 1988–1989, and the minimum number of adult residents known to be alive in the lake dropped from 47 in 1986 to 16 in 1989. In 1986 and 1987, annual adult female survivorship was estimated at 80 and 55%, respectively, and estimated numbers of nesting females declined from 82 in 1986 to 71 and 55 in 1987 and 1988, respectively. The actual number of nests found declined by 38 and 20% over the same periods. Although no significant differences occurred in mean egg mass or mean clutch size between 1987 and 1989 and earlier years, the mean clutch mass in 1988 was larger than in 1977 or 1978. This difference appeared to be due to a gradual increase in the mean age and body size of breeding females rather than to density-dependent changes. Recruitment into the adult breeding female population in 1987–1989 remained less than two individuals per year. Hatchling survival and number of juveniles were low throughout the study. Our observations support the view that populations of species with high, stochastic juvenile mortality and long adult life spans may be decimated quickly by increased mortality of adult animals, particularly if numbers of juveniles and immigrants are low. Recovery of such populations should be very slow because of a lack of effective density-dependent response in reproduction and recruitment.

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Representation and Reasoning about Strategic Abilities with ω-Regular Properties

Mathematics ◽

10.3390/math9233052 ◽

2021 ◽

Vol 9 (23) ◽

pp. 3052

Author(s):

Liping Xiong ◽

Sumei Guo

Keyword(s):

Temporal Logic ◽

Linear Time ◽

Dynamic Logic ◽

Research Area ◽

Regular Expressions ◽

Multi Agent Systems ◽

Practical Applications ◽

Multi Agent ◽

Strategy Logic ◽

Active Research

Specification and verification of coalitional strategic abilities have been an active research area in multi-agent systems, artificial intelligence, and game theory. Recently, many strategic logics, e.g., Strategy Logic (SL) and alternating-time temporal logic (ATL*), have been proposed based on classical temporal logics, e.g., linear-time temporal logic (LTL) and computational tree logic (CTL*), respectively. However, these logics cannot express general ω-regular properties, the need for which are considered compelling from practical applications, especially in industry. To remedy this problem, in this paper, based on linear dynamic logic (LDL), proposed by Moshe Y. Vardi, we propose LDL-based Strategy Logic (LDL-SL). Interpreted on concurrent game structures, LDL-SL extends SL, which contains existential/universal quantification operators about regular expressions. Here we adopt a branching-time version. This logic can express general ω-regular properties and describe more programmed constraints about individual/group strategies. Then we study three types of fragments (i.e., one-goal, ATL-like, star-free) of LDL-SL. Furthermore, we show that prevalent strategic logics based on LTL/CTL*, such as SL/ATL*, are exactly equivalent with those corresponding star-free strategic logics, where only star-free regular expressions are considered. Moreover, results show that reasoning complexity about the model-checking problems for these new logics, including one-goal and ATL-like fragments, is not harder than those of corresponding SL or ATL*.

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Acquisition of High Precision Images for Non-Contact Atomic Force Microscopy via Direct Identification of Sample Height

Dynamic Systems and Control, Parts A and B ◽

10.1115/imece2005-81627 ◽

2005 ◽

Author(s):

H. N. Pishkenari ◽

Nader Jalili ◽

A. Meghdari

Keyword(s):

High Precision ◽

Single Mode ◽

Scanning Speed ◽

Sample Surface ◽

Biological Species ◽

Atomic Scale ◽

Contact Mode ◽

Practical Applications ◽

Atomic Force ◽

Sample Height

Atomic force microscopes (AFM) can image and manipulate sample properties at the atomic scale. The non-contact mode of AFM offers unique advantages over other contemporary scanning probe techniques, especially when utilized for reliable measurements of soft samples (e.g., biological species). The distance between cantilever tip and sample surface is a time varying parameter even for a fixed sample height, and hence, difficult to identify. A remedy to this problem is to directly identify the sample height in order to generate high precision, atomic-resolution images. For this, the microcantilever is modeled by a single mode approximation and the interaction between the sample and cantilever is derived from a van der Waals potential. Since in most practical applications only the microcantilever deflection is accessible, this measurement is utilized to identify the sample height in each point. Using the proposed approach for identification of the sample height, the scanning speed can be increased significantly. Furthermore, for taking atomic-scale images of atomically flat samples, there is no need to use the feedback loop to achieve setpoint amplitude. Simulation results are provided to demonstrate the effectiveness of the approach and suggest the most suitable technique for the sample height identification.

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Study on High-Precision Computer-Controlled Aspheric Surface Processing Techniques

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.314-316.1750 ◽

2011 ◽

Vol 314-316 ◽

pp. 1750-1753

Author(s):

Chuan Zhang ◽

Ping Wang ◽

Yao Long Chen

Keyword(s):

High Precision ◽

Processing Technology ◽

Surface Grinding ◽

Aspheric Surface ◽

Optical Surface ◽

Surface Processing ◽

Traditional Technique ◽

Accuracy Of Measurement ◽

Computer Controlled ◽

Processing Techniques

In this paper, two processing techniques—full parameters technique and part parameters technique—for aspheric surface grinding are expatiated. Both of them are based on the priciple of computer-controlled optical surface (CCOS) and developed from trajectory forming method. We also have carried out appropriative software to digitalize processing technology. Proved by practical process, both of them are reliable and reproducible. Full parameters technique is easy to operate, but the accuracy of surface is to large extent dependent on the accuracy of measurement; Part parameters technique can avoid these measurements, however, it has certain requirements for operator. However, its requirements are still much less than those of traditional technique.

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Research on Automatic Monitoring System with Measurement Robot

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.217-218.1324 ◽

2011 ◽

Vol 217-218 ◽

pp. 1324-1329

Author(s):

Yan Hua Mi ◽

Li Xin Liu ◽

Li Fang Lai

Keyword(s):

Monitoring System ◽

High Precision ◽

Data Transmission ◽

High Efficiency ◽

Vertical Direction ◽

Automatic Monitoring ◽

Automatic Monitoring System ◽

Practical Applications ◽

Precise Data ◽

Very High

This paper introduced the characteristics of functions of the automatic monitoring system on surveys robot (TCA total station ). Has analyzed the application situation and the precision of the automatic monitoring system. Practical applications indicated that this system had high efficiency and precise data transmission. The achievement of surveys achieved very high precision in both horizon talplane and vertical direction. The results can provide technology references for similarprojects.

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Flexible 6-in-1 Microsensor for Real-Time Microscopic Monitoring of Proton Battery

Membranes ◽

10.3390/membranes11080615 ◽

2021 ◽

Vol 11 (8) ◽

pp. 615

Author(s):

Chi-Yuan Lee ◽

Chia-Hung Chen ◽

Chin-Yuan Yang ◽

John-Shong Cheong ◽

Yun-Hsiu Chien ◽

...

Keyword(s):

Proton Exchange Membrane ◽

Water Electrolysis ◽

Research Area ◽

Carbon Layer ◽

Proton Exchange ◽

Physical Parameters ◽

Proton Battery ◽

Practical Applications ◽

Mems Technology ◽

Physical Quantities

According to the comparison between a proton battery and a proton exchange membrane fuel cell (PEMFC), the PEMFC requires oxygen and hydrogen for generating electricity, so a hydrogen tank is required, leading to larger volume of PEMFC. The proton battery can store hydrogen in the carbon layer, combined with the oxygen in the air to form water to generate electricity; thus, the battery cost and the space for a hydrogen tank can be reduced a lot, and it is used more extensively. As the proton battery is a new research area, multiple important physical quantities inside the proton battery should be further understood and monitored so as to enhance the performance of battery. The proton battery has the potential for practical applications, as well as water electrolysis, proton storage and discharge functions, and it can be produced without expensive metals. Therefore, in this study, we use micro-electro-mechanical systems (MEMS) technology to develop a diagnostic tool for the proton battery based on the developed microhydrogen sensor, integrated with the voltage, current, temperature, humidity and flow microsensors developed by this laboratory to complete a flexible integrated 6-in-1 microsensor, which is embedded in the proton battery to measure internal important physical parameters simultaneously so that the reaction condition in the proton battery can be mastered more accurately. In addition, the interaction of physical quantities of the proton battery are discussed so as to enhance the proton battery’s performance.

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Analysis of the Wavelet Domain Filtering Approach for Video Super-Resolution

Engineering, Technology & Applied Science Research ◽

10.48084/etasr.4262 ◽

2021 ◽

Vol 11 (4) ◽

pp. 7477-7482

Author(s):

M. V. Daithankar ◽

S. D. Ruikar

Keyword(s):

High Frequency ◽

Low Frequency ◽

Super Resolution ◽

Visual Quality ◽

Research Area ◽

Wavelet Domain ◽

Edge Information ◽

Algorithm Efficiency ◽

Frequency Components ◽

Processing Techniques

The wavelet domain-centered algorithms for the super-resolution research area give better visual quality and have been explored by different researchers. The visual quality is achieved with increased complexity and cost as most of the systems embed different pre- and post-processing techniques. The frequency and spatial domain-based methods are the usual approaches for super-resolution with some benefits and limitations. Considering the benefits of wavelet domain processing, this paper deals with a new algorithm that depends on wavelet residues. The methodology opts for wavelet domain filtering and residue extraction to get super-resolved frames for better visuals without embedding other techniques. The avoidance of noisy high-frequency components from low-quality videos and the consideration of edge information in the frames are the main targets of the super-resolution process. This inverse process is carried with a proper combination of information present in low-frequency bands and residual information in the high-frequency components. The efficient known algorithms always have to sacrifice simplicity to achieve accuracy, but in the proposed algorithm efficiency is achieved with simplicity. The robustness of the algorithm is tested by analyzing different wavelet functions and at different noise levels. The proposed algorithm performs well in comparison to other techniques from the same domain.

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eNetXplorer: an R package for the quantitative exploration of elastic net families for generalized linear models

10.1101/305870 ◽

2018 ◽

Cited By ~ 1

Author(s):

Julián Candia ◽

John S. Tsang

Keyword(s):

Generalized Linear Models ◽

Linear Models ◽

Statistical Significance ◽

Model Fitting ◽

Predictive Performance ◽

R Package ◽

Research Area ◽

Elastic Net ◽

Feature Identification ◽

Practical Applications

AbstractBackgroundRegularized generalized linear models (GLMs) are popular regression methods in bioinformatics, particularly useful in scenarios with fewer observations than parameters/features or when many of the features are correlated. In both ridge and lasso regularization, feature shrinkage is controlled by a penalty parameter λ. The elastic net introduces a mixing parameter α to tune the shrinkage continuously from ridge to lasso. Selecting α objectively and determining which features contributed significantly to prediction after model fitting remain a practical challenge given the paucity of available software to evaluate performance and statistical significance.ResultseNetXplorer builds on top of glmnet to address the above issues for linear (Gaussian), binomial (logistic), and multinomial GLMs. It provides new functionalities to empower practical applications by using a cross validation framework that assesses the predictive performance and statistical significance of a family of elastic net models (as α is varied) and of the corresponding features that contribute to prediction. The user can select which quality metrics to use to quantify the concordance between predicted and observed values, with defaults provided for each GLM. Statistical significance for each model (as defined by α) is determined based on comparison to a set of null models generated by random permutations of the response; the same permutation-based approach is used to evaluate the significance of individual features. In the analysis of large and complex biological datasets, such as transcriptomic and proteomic data, eNetXplorer provides summary statistics, output tables, and visualizations to help assess which subset(s) of features have predictive value for a set of response measurements, and to what extent those subset(s) of features can be expanded or reduced via regularization.ConclusionsThis package presents a framework and software for exploratory data analysis and visualization. By making regularized GLMs more accessible and interpretable, eNetXplorer guides the process to generate hypotheses based on features significantly associated with biological phenotypes of interest, e.g. to identify biomarkers for therapeutic responsiveness. eNetXplorer is also generally applicable to any research area that may benefit from predictive modeling and feature identification using regularized GLMs.Availability and implementationThe package is available under GPL-3 license at the CRAN repository, https://CRAN.R-project.org/package=eNetXplorer

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Comparing cost and print time estimates for six commercially-available 3D printers obtained through slicing software for clinically relevant anatomical models

10.21203/rs.3.rs-50148/v2 ◽

2020 ◽

Author(s):

Joshua Vic Chen ◽

Alan BC Dang ◽

Alexis Dang

Keyword(s):

Cost Effective ◽

Patient Specific ◽

Anatomical Models ◽

Worst Case ◽

Layer Height ◽

Orthopaedic Care ◽

Horizontal Orientation ◽

3D Printers ◽

The Difference ◽

Digital Anatomy

Abstract Background3D printed patient-specific anatomical models have been applied clinically to orthopaedic care for surgical planning and patient education. The estimated cost and print time per model for 3D printers have not yet been compared with clinically representative models across multiple printing technologies. This study investigates six commercially-available 3D printers: Prusa i3 MK3S, Formlabs Form 2, Formlabs Form 3, LulzBot TAZ 6, Stratasys F370, and Stratasys J750 Digital Anatomy.MethodsSeven representative orthopaedic standard tessellation models derived from CT scans were imported into the respective slicing software for each 3D printer. For each printer and corresponding print setting, the slicing software provides a print time and material use estimate. Material quantity was used to calculate estimated model cost. Print settings investigated were infill percentage, layer height, and model orientation on the print bed. The slicing software investigated are Cura LulzBot Edition 3.6.20, GrabCAD Print 1.43, PreForm 3.4.6, and PrusaSlicer 2.2.0.ResultsThe effect of changing infill between 15% and 20% on estimated print time and material use was negligible. Orientation of the model has considerable impact on time and cost with worst-case differences being as much as 39.30% added print time and 34.56% added costs. Averaged across all investigated settings, horizontal model orientation on the print bed minimizes estimated print time for all 3D printers, while vertical model orientation minimizes cost with the exception of Stratasys J750 Digital Anatomy, in which horizontal orientation also minimized cost. Decreasing layer height for all investigated printers increased estimated print time and decreased estimated cost with the exception of Stratasys F370, in which cost increased. The difference in material cost was two orders of magnitude between the least and most-expensive printers. The difference in build rate (cm3/min) was one order of magnitude between the fastest and slowest printers.ConclusionsAll investigated 3D printers in this study have the potential for clinical utility. Print time and print cost are dependent on orientation of anatomy and the printers and settings selected. Cost-effective clinical 3D printing of anatomic models should consider an appropriate printer for the complexity of the anatomy and the experience of the printer technicians.

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