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1
Kowalska, Wiktoria, Ewa Jędrzejczyk-Patej, Aleksandra Konieczny, Jonasz Kozielski, Maciej Bugajski, Aleksandra Woźniak, Oskar Kowalski, and Beata Średniawa. "Medtronic Micra leadless pacemaker implantation to patient with artificial tricuspid valve." In a good rythm 4, no. 45 (December 29, 2017): 16–19. http://dx.doi.org/10.5604/01.3001.0010.7492.
Повний текст джерелаАнотація:
In case of the need of pacemaker implantation, patients with artificial tricuspid valve are a special group of subjects, because of high risk of dysfunction of the prosthesis. In case of mechanical prosthesis of tricuspid valve the leads of pacemaker are usually located in coronary sinus. In case of biological prosthesis of tricuspid valve despite of the risk of prosthesis damage the electrodes are implanted endocardially. The leadless pacemakers seems to be promising alternative in patients with artificial tricuspid valve because of minor risk of valve damage. The case report concerns to the patient with tachycardia-bradycardia syndrome and biological prosthesis of tricuspid valve in whom the leadless pacemaker Micra was implanted.
2
Askadinov, M. N., B. K. Kadyraliev, S. H. Lilotkhia, O. G. Musaev, and V. B. Arutyunyan. "Aortic valve leaflet replacement using autopericardium as an alternative approach of aortic valve stenosis treatment: literature review." Perm Medical Journal 37, no. 5 (January 7, 2021): 52–60. http://dx.doi.org/10.17816/pmj37552-60.
Повний текст джерелаАнотація:
Regarding degenerative defects of the aortic valve, the main method of treatment is dissection of malformed leaflets and placement of prosthetic valve. In most cases, mechanical and biological prostheses are used. Each type of prosthesis has shortcomings related to both the implantation technique and essential medication support to keep it functioning. Patients with implanted mechanical prosthesis need lifelong anticoagulation therapy and constant monitoring of blood coagulation rates, where on the one hand there is a risk of occurring thromboembolic complications, and on the other hand haemorrhagic complications. The peculiarity of biological prostheses is a high probability of degeneration and the need for re-operation, especially in young patients, therefore the implantation of such prostheses is mainly carried out in elderly patients. Despite continuous change and modification of artificial valves, the ideal aortic valve prosthesis does not exist today. Various attempts to replace aortic valve leaflets with artificial and biological materials have not succeeded or gained great recognition. In 2007, Shigeyuki Ozaki introduced a technique to replace the aortic valve leaflets with an autopericardium treated with 0.6 % glutar aldehyde solution. Inspite of the encouraging mid-term results, this surgery has not yet become widespread among cardiac surgeons due to the complicated operating technique and lack of long-term results. Considering the research of literature, experience of different cardiosurgical centers in this field as well as our own experience, there is a need to systematize the results of Ozaki procedure, among patients with aortic valve pathology, presented in the recent publications.
3
Askadinov, M. N., B. K. Kadyraliev, S. H. Lilotkhia, O. G. Musaev, and V. B. Arutyunyan. "Aortic valve leaflet replacement using autopericardium as an alternative approach of aortic valve stenosis treatment: literature review." Perm Medical Journal 37, no. 5 (January 7, 2021): 52–60. http://dx.doi.org/10.17816/pmj37552-60.
Повний текст джерелаАнотація:
Regarding degenerative defects of the aortic valve, the main method of treatment is dissection of malformed leaflets and placement of prosthetic valve. In most cases, mechanical and biological prostheses are used. Each type of prosthesis has shortcomings related to both the implantation technique and essential medication support to keep it functioning. Patients with implanted mechanical prosthesis need lifelong anticoagulation therapy and constant monitoring of blood coagulation rates, where on the one hand there is a risk of occurring thromboembolic complications, and on the other hand haemorrhagic complications. The peculiarity of biological prostheses is a high probability of degeneration and the need for re-operation, especially in young patients, therefore the implantation of such prostheses is mainly carried out in elderly patients. Despite continuous change and modification of artificial valves, the ideal aortic valve prosthesis does not exist today. Various attempts to replace aortic valve leaflets with artificial and biological materials have not succeeded or gained great recognition. In 2007, Shigeyuki Ozaki introduced a technique to replace the aortic valve leaflets with an autopericardium treated with 0.6 % glutar aldehyde solution. Inspite of the encouraging mid-term results, this surgery has not yet become widespread among cardiac surgeons due to the complicated operating technique and lack of long-term results. Considering the research of literature, experience of different cardiosurgical centers in this field as well as our own experience, there is a need to systematize the results of Ozaki procedure, among patients with aortic valve pathology, presented in the recent publications.
4
Maciejewski, Marek, Katarzyna Piestrzeniewicz, Agata Bielecka-Dabrowa, and Andrzej Walczak. "Biological artificial valve dysfunction – single-centre, observational echocardiographic study in patients operated on before age 65 years." Archives of Medical Science 6 (2011): 993–99. http://dx.doi.org/10.5114/aoms.2011.26611.
Повний текст джерела
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Arbeiter, Daniela, Christoph Brandt-Wunderlich, Stefan Siewert, Stefanie Kohse, Sylvia Pfensig, Klaus-Peter Schmitz, and Niels Grabow. "Cyclic stress-strain behavior of polymeric nonwoven structures for the use as artificial leaflet material for transcatheter heart valve prostheses." Current Directions in Biomedical Engineering 3, no. 2 (September 7, 2017): 703–6. http://dx.doi.org/10.1515/cdbme-2017-0149.
Повний текст джерелаАнотація:
AbstractXenogenic leaflet material, bovine and porcine pericardium, is widely used for the fabrication of surgically implanted and transcatheter heart valve prostheses. As a biological material, long term durability of pericardium is limited due to calcification, degeneration and homogeneity. Therefore, polymeric materials represent a promising approach for a next generation of artificial heart valve leaflets with improved durability. Within the current study we analyzed the mechanical performance of polymeric structures based on elastomeric materials. Polymeric cast films were prepared and nonwovens were manufactured in an electrospinning process. Analysis of cyclic stress-strain behavior was performed, using a universal testing machine. The uniaxial cyclic tensile experiments of the elastomeric samples yielded a non-linear elastic response due to viscoelastic behavior with hysteresis. Equilibrium of stress-strain curves was found after a specific number of cycles, for cast films and nonwovens, respectively. In conclusion, preconditioning was found obligatory for the evaluation of the mechanical performance of polymeric materials for the use as artificial leaflet material for heart valve prostheses.
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Grams, Samantha Torres, Karen Yumi Mota Kimoto, Elen Moda de Oliveira Azevedo, Marina Lança, André Luis Pereira de Albuquerque, Christina May Moran de Brito, and Wellington Pereira Yamaguti. "Unidirectional Expiratory Valve Method to Assess Maximal Inspiratory Pressure in Individuals without Artificial Airway." PLOS ONE 10, no. 9 (September 11, 2015): e0137825. http://dx.doi.org/10.1371/journal.pone.0137825.
Повний текст джерела
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Vemula, Dheeraj, Jeong Yong Kim, Nicholas Mazzoleni, and Matthew Bryant. "Design, analysis, and validation of an orderly recruitment valve for bio-inspired fluidic artificial muscles." Bioinspiration & Biomimetics 17, no. 2 (January 24, 2022): 026001. http://dx.doi.org/10.1088/1748-3190/ac4381.
Повний текст джерелаАнотація:
Abstract Biological musculature employs variable recruitment of muscle fibers from smaller to larger units as the load increases. This orderly recruitment strategy has certain physiological advantages like minimizing fatigue and providing finer motor control. Recently fluidic artificial muscles (FAM) are gaining popularity as actuators due to their increased efficiency by employing bio-inspired recruitment strategies such as active variable recruitment (AVR). AVR systems use a multi-valve system (MVS) configuration to selectively recruit individual FAMs depending on the load. However, when using an MVS configuration, an increase in the number of motor units in a bundle corresponds to an increase in the number of valves in the system. This introduces greater complexity and weight. The objective of this paper is to propose, analyze, and demonstrate an orderly recruitment valve (ORV) concept that enables orderly recruitment of multiple FAMs in the system using a single valve. A mathematical model of an ORV-controlled FAM bundle is presented and validated by experiments performed on a proof-of-concept ORV experiment. The modeling is extended to explore a case study of a 1-DOF robot arm system consisting of an electrohydraulic pressurization system, ORV, and a FAM-actuated rotating arm plant and its dynamics are simulated to further demonstrate the capabilities of an ORV-controlled closed-loop system. An orderly recruitment strategy was implemented through a model-based feed forward controller. To benchmark the performance of the ORV, a conventional MVS with equivalent dynamics and controller was also implemented. Trajectory tracking simulations on both the systems revealed lower tracking error for the ORV controlled system compared to the MVS controlled system due to the unique cross-flow effects present in the ORV. However, the MVS, due to its independent and multiple valve setup, proved to be more adaptable for performance. For example, modifications to the recruitment thresholds of the MVS demonstrated improvement in tracking error, albeit with a sacrifice in efficiency. In the ORV, tracking performance remained insensitive to any variation in recruitment threshold. The results show that compared to the MVS, the ORV offers a simpler and more compact valving architecture at the expense of moderate losses in control flexibility and performance.
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Christo, SW, TM Absher, and G. Boehs. "Morphology of the larval shell of three oyster species of the genus Crassostrea Sacco, 1897 (Bivalvia: Ostreidae)." Brazilian Journal of Biology 70, no. 3 (August 2010): 645–50. http://dx.doi.org/10.1590/s1519-69842010000300023.
Повний текст джерелаАнотація:
In this study we describe the morphology of the larval shell of three oyster species of Crassostrea genus. Two species, C. rhizophorae and C. brasiliana, are native to the Brazilian coast, and C. gigas is an introduced species. Samples of laboratory reared larvae, obtained through artificial fertilisation, were collected at intervals during the cultivation process for analysis using Scanning Electron Microscopy (SEM). Prodissoconch morphology was observed in relation to the presence, position, form and number of teeth in the three larval stages: D-shaped larva, umbo larva and pediveliger. Characteristic of D-shaped larvae of C. rhizophorae was the total absence of teeth in the provinculum area while C. brasiliana and C. gigas had two anterior and two posterior teeth in each valve. In the umbo larval phase, the three species had the same number of teeth in each valve: two posterior and two anterior teeth in the right valve and three posterior and three anterior in the left valve. In the pediveliger stage the three species could be differentiated by the number of anterior teeth of the right valve: C. rhizophorae had two teeth, C. brasiliana one tooth and C. gigas three teeth.
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Schubert, Julia, Kerstin Schümann, Sabine Kischkel, Wolfram Schmidt, Niels Grabow, Michael Stiehm, Sylvia Pfensig, Klaus-Peter Schmitz, Jonas Keiler, and Andreas Wree. "Numerical simulation of the functionality of a stent structure for venous valve prostheses." Current Directions in Biomedical Engineering 5, no. 1 (September 1, 2019): 477–79. http://dx.doi.org/10.1515/cdbme-2019-0120.
Повний текст джерелаАнотація:
AbstractChronic venous insufficiency (CVI) is a common disease characterized by impaired venous drainage leading to congestion in the lower limbs. Currently, there are no artificial or biological venous valve prostheses commercially available. Previous minimally invasive design concepts failed to achieve sufficient long term results in animal or in vitro studies. The aim was to implement structural numerical simulation of clinically relevant loading cases for minimally invasive implantable venous valve prostheses. A bicuspid valve design was chosen as it showed superior results compared to tricuspid valves in previous studies. The selfexpanding support structure was developed by using diamond-shaped elements. Using finite-element analysis (FEA), various loading cases, including expansion and crimping of the stent structure and the release into a venous vessel, were simulated. A hyperelastic constitutive law for the vascular model was generated from uniaxial tensile test data of unfixated human vein walls. This study also compared numerical and experimental results regarding compliance and tensile tests to validate the vein material model. The calculated performance concerning expansion and crimping, as well as the release of the stent into a venous vessel, demonstrated the suitability of the stent design for minimally invasive application.
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Wilczek, P. "Heart valve bioprothesis; effect of different acellularizations methods on the biomechanical and morphological properties of porcine aortic and pulmonary valve." Bulletin of the Polish Academy of Sciences: Technical Sciences 58, no. 2 (June 1, 2010): 337–42. http://dx.doi.org/10.2478/v10175-010-0032-4.
Повний текст джерелаАнотація:
Heart valve bioprothesis; effect of different acellularizations methods on the biomechanical and morphological properties of porcine aortic and pulmonary valveTissue engineering is a promising tool for the creation of a new type of the heart valve bioprothesis. The biological scaffold composed of decellularized tissue has been successfully used for the constructions of the valve prosthesis. An analysis of the efficiency of the valve leaflet acellularization methods and the influence of those methods on the morphology and the biomechanical properties of the ECM (extra cellular matrix) was performed. Fresh porcine hearts obtained from a slaughterhouse were used in the experiments. The efficiency of the acellularization methods was dependent on the tissue type and the acellularoization methods used. The more effective were the enzymatic methods, both because of the cell removal efficiency and the effect on the biomechanical properties of the heart valve. The differences in the biomechanical and morphological properties of the porcine aortic and the pulmonary valve after different types of the acellularization process could influence the hemodynamic conditions of the heart after the valve replacement, which limited the range of the tissue types used for the creations of the tissue engineered heart valve.
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Philippart, Raphael, Anne Brunet-Bernard, Nicolas Clementy, Thierry Bourguignon, Alain Mirza, Denis Angoulvant, Dominique Babuty, Gregory Y. H. Lip, and Laurent Fauchier. "Oral anticoagulation, stroke and thromboembolism in patients with atrial fibrillation and valve bioprosthesis." Thrombosis and Haemostasis 115, no. 05 (2016): 1056–63. http://dx.doi.org/10.1160/th16-01-0007.
Повний текст джерелаАнотація:
SummaryVitamin K antagonists are currently recommended in patients with ‘valvular’ atrial fibrillation (AF), e. g. those having mitral stenosis or artificial heart valves. We compared thromboembolic risk in patients with ‘non valvular’ AF and in those with AF and biological valve replacement (valve bioprosthesis). Among 8962 AF patients seen between 2000 and 2010, a diagnosis of ‘non-valvular AF’ was found in 8053 (94 %). Among patients with ‘valvular’ AF, 549 (6 %) had a biological prosthesis. The patients with bioprosthesis were older and had a higher CHA2DS2-VASc score than those with non valvular AF. After a follow-up of 876 é 1048 days (median 400 days, interquartile range 12–1483), the occurrence of thromboembolic events was similar in AF patients with bioprosthesis compared to those with ‘non valvular’ AF (hazard ratio [HR] 1.10 95 % confidence interval [CI] 0.83–1.45, p=0.52, adjusted HR 0.93, 95 %CI 0.68–1.25, p=0.61). Factors independently associated with increased risk of stroke/TE events were older age (HR 1.25, 95 %CI 1.16–1.34 per 10-year increase, p> 0.0001) and higher CHA2DS2-VASc score (HR 1.35, 95 %CI 1.24–1.46, p> 0.0001) whilst female gender (HR 0.75, 95 %CI 0.62–0.90, p=0.002), use of vitamin K antagonist (HR 0.83, 95 %CI 0.71–0.98, p=0.03) were independently associated with a lower risk of stroke/TE. Neither the presence of bioprosthesis nor the location of bioprosthesis was independent predictor for TE events. In conclusion, AF patients with bioprosthesis had a non-significantly higher risk of stroke/TE events compared to patients with non-valvular AF. Second, the CHA2DS2-VASc score was independently associated with an increased risk of TE events, and was a valuable determinant of TE risk both in AF patients with non-valvular AF as well as those with bioprosthesis, whether treated or not treated with OAC.Note: The review process for this paper was fully handled by Christian Weber, Editor in Chief.
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Ovcharenko, Evgeny, Maria Rezvova, Pavel Nikishau, Sergei Kostjuk, Tatiana Glushkova, Larisa Antonova, Dmitry Trebushat, et al. "Polyisobutylene-Based Thermoplastic Elastomers for Manufacturing Polymeric Heart Valve Leaflets: In Vitro and In Vivo Results." Applied Sciences 9, no. 22 (November 8, 2019): 4773. http://dx.doi.org/10.3390/app9224773.
Повний текст джерелаАнотація:
Superior polymers represent a promising alternative to mechanical and biological materials commonly used for manufacturing artificial heart valves. The study is aimed at assessing poly(styrene-block-isobutylene-block-styrene) (SIBS) properties and comparing them with polytetrafluoroethylene (Gore-texTM, a reference sample). Surface topography of both materials was evaluated with scanning electron microscopy and atomic force microscopy. The mechanical properties were measured under uniaxial tension. The water contact angle was estimated to evaluate hydrophilicity/hydrophobicity of the study samples. Materials’ hemocompatibility was evaluated using cell lines (Ea.hy 926), donor blood, and in vivo. SIBS possess a regular surface relief. It is hydrophobic and has lower strength as compared to Gore-texTM (3.51 MPa vs. 13.2/23.8 MPa). SIBS and Gore-texTM have similar hemocompatibility (hemolysis, adhesion, and platelet aggregation). The subcutaneous rat implantation reports that SIBS has a lower tendency towards calcification (0.39 mg/g) compared with Gore-texTM (1.29 mg/g). SIBS is a highly hemocompatible material with a promising potential for manufacturing heart valve leaflets, but its mechanical properties require further improvements. The possible options include the reinforcement with nanofillers and introductions of new chains in its structure.
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Molchanov, Andrey N., Valery V. Romachkin, and Irina A. Urvantseva. "Evaluation of quality of life in elderly patients moving surgical correction of aortal valve stenosis." CardioSomatics 10, no. 3 (September 15, 2019): 71–78. http://dx.doi.org/10.26442/22217185.2019.3.190569.
Повний текст джерелаАнотація:
Aim. Conduct a comparative analysis of the patient's quality of life in the long-term period after surgical correction of aortic valve stenosis after undergoing transcatheter aortic valve replacement with the results of patients undergoing aortic valve replacement with a seamless biological prosthesis under artificial blood circulation. Materials and methods. A comprehensive examination and dynamic observation in the middle and late postoperative period for 251 patients of the older age group with aortic stenosis was performed. The average age of patients at the time of treatment was 67.62±9.94 years. Group 1 included 128 patients who underwent transcatheter aortic valve replacement. In turn, Group 1 is divided into two subgroups. Subgroup A consisted of 56 patients, due to the severity of the underlying disease, concomitant pathology EuroSCORE II more than 20% and STS SCORE more than 10%. Subgroup B consisted of 72 patients with a risk of outcome of EuroSCORE II surgical intervention less than 20% and STS SCORE less than 10%. Group 2 patients (n=123) were comparable to subgroup B by the severity of the underlying disease EuroSCORE II less than 20% and STS SCORE less than 10%. All patients in group II underwent aortic valve replacement under artificial circulation.To assess the quality of life, the SF-36 questionnaire was used 12, 24, 36, 48 and 60 months after surgery. Results. The greatest increase in the total total score in the postoperative period was noted in subgroup A - 3 times (p=0.000001), and in subgroups B and group 2 was 2.66 times (p=0.0000011). By the end of the observation period, the highest total score was recorded in subgroup B, in subgroup A it was lower by 3% (p=0.95), in group 2 - by 2.4% (p=0.97). A correlation is established between the average degree between the total score, reflecting the quality of life of patients after aortic valve replacement, and the rate of ejection fraction (R=0.23, p=0.034), and the left ventricular myocardium mass (R=-0.25, p=0.028) and shock volume (R=0.29, p=0.021) according to echocardiography. Conclusions. Thus, despite a number of difficulties that were observed after surgical correction of aortic stenosis in patients of the older age group, including the presence of concomitant somatic pathology, marked cardiac changes according to echocardiography, the analysis of quality of life indicators demonstrates the positive effect of surgical treatment with a significant improvement in quality of life.
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Matschegewski, Claudia, Jörn-Bo Matthies, Niels Grabow, and Klaus-Peter Schmitz. "Cell adhesion and viability of human endothelial cells on electrospun polymer scaffolds." Current Directions in Biomedical Engineering 2, no. 1 (September 1, 2016): 11–14. http://dx.doi.org/10.1515/cdbme-2016-0006.
Повний текст джерелаАнотація:
AbstractThe usage of electrospun polymer scaffolds is a promising approach for artificial heart valve design. This study aims at the evaluation of biological performance of nanofibrous polymer scaffolds poly(L-lactide) PLLA L210, PLLA L214 and polyamide-6 fabricated by electrospinning via analyzing viability, adhesion and morphology of human umbilical vein endothelial cells (EA.hy926). Nanofibrous surface topography was shown to influence cell phenotype and cell viability according to the observation of diminished cell spreading accompanied with reduced cell viability on nonwovens. Among those, highest biocompatibility was assessed for PLLA L214, although being generally low when compared to the planar control surface. Electrospinning was demonstrated as an innovative technique for the fabrication of advanced biomaterials aiming at guided cellular behavior as well as the design of novel implant platforms. A better understanding of cell–biomaterial interactions is desired to further improve implant development.
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Patel, Shital, Cynthia Wong, Yos S. Morsi, Xiu Mei Mo, and Chen Rui. "Endothelialisation and Cell Retention on Gelatin Chitosan-Coated Electrospun Polyurethane, Poly (Lactide-Co-Glycolide) and Collagen-Coated Pericardium." Advanced Materials Research 32 (February 2008): 233–36. http://dx.doi.org/10.4028/www.scientific.net/amr.32.233.
Повний текст джерелаАнотація:
Arterial bypass and heart valve replacements are two of the most common surgical treatments in cardiovascular surgery today. Currently, artificial materials are used as substitute for these cardiac tissues. However, these foreign materials do not have the ability to grow, repair or remodel and are thrombogenic, leading to stenosis. With the aid of tissue engineering, it is possible to develop functional identical copies of healthy heart valves and arteries, which are biocompatible. Although much effort has been made into this area, there are still inconsistencies with respect to endothelialisation and cell retention on synthetic biological grafts. These variations may be attributed to differences in factors such as cell seeding density, incubation periods and effects of shear stress. In this study, we have compared the endothelialisation and cell retention between gelain chitosan-coated electrospun polyurethane (PU), poly (lactide-co-glycolide) (PGA/PLA) and collagen-coated pericardium. Endothelial cells adhered to all of the materials as early as 1–day post seeding. After 7-day of seeding, the coverage on PU was almost 45% and that on PGA/PLA was about 25% and the least was on collagen-coated pericardium of approximately 15%. It was observed that the PU showed superior cell coverage and cell retention in comparison to the PGA/PLA and collagen-coated pericardium.
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Frater, Robert W. M., Guangfu Gong, Darryl Hoffman, and Kangxiong Liao. "Endothelial covering of biological artificial heart valves." Annals of Thoracic Surgery 53, no. 3 (March 1992): 371–72. http://dx.doi.org/10.1016/0003-4975(92)90252-y.
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Suresh, Aswath, Ganesha Udupa, and Dhruv Gaba. "Design and development of soft robotic hand for vertical farming in spacecraft." IAES International Journal of Robotics and Automation (IJRA) 9, no. 1 (March 1, 2020): 6. http://dx.doi.org/10.11591/ijra.v9i1.pp6-16.
Повний текст джерелаАнотація:
<p>For colonization in deep space we need to explore the feasibility of a bioregenerative system in microgravity or artificial gravity environments. The process has various complexities form ranging to biological obstacles to engineering limitations of the spacecraft. Concentration of microbes in the confinements of a spacecraft can be fatal for the crew. In this paper, a solution to the elevated microbial levels by farming using robots is discussed. The soft robotic arm is made up of Asymmetric Flexible Pneumatic Actuator (AFPA). The AFPA under internal pressure will curve in the direction of the side having greater thickness as the expansion of the thinner side (outside radius) will be more than thicker side (inside radius) due to differential expansion and moment induced due to eccentricity. Simulation results demonstrate that bending based on AFPA can meet the designed requirement of application. The AFPA is used for five fingers of the robotic hand. The safe, soft touch and gentle motion of the bellow (AFPA) gives the feel of real human hand. The internal pressure of the AFPA is controlled using a solenoid valve which is interfaced using an Arduino microcontroller for hand like moves. The bending of the fingers and degree of freedom (DOF) of the joints of the hand is controlled using an IMU and flex sensor. Wireless connection of the hand and the control system is implemented using XBee pro 60mW with a range of 1 miles.The pneumatic soft robotic hand is made up of solenoid valve, Mini Compressor, AFPA bellow, and Servos. This soft robotic hand has many advantages such as good adaptability, simple structure, small size, high flexibility and less energy loss. As an extension Manual control of the robot using a virtual reality environment and well as some possible aspects of an automated farming systems can be considered as future additions.</p>
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Polak, Omer, and Nadav Shashar. "Economic value of biological attributes of artificial coral reefs." ICES Journal of Marine Science 70, no. 4 (May 22, 2013): 904–12. http://dx.doi.org/10.1093/icesjms/fst014.
Повний текст джерелаАнотація:
Abstract Polak, O., and Shashar, N. 2013. Economic value of biological attributes of artificial coral reefs – ICES Journal of Marine Science, 70: 904–912. Visitor appreciation of natural scenes such as coral reefs is well documented. However, what part the value of the biological component in these scenes plays in fostering people's enjoyment is unclear. Using the contingent valuation method (CVM), we examined divers' willingness to pay for changes in the fish and coral attributes over an artificial reef. Using image manipulations, different levels of community descriptors, such as richness, abundance, and biodiversity of corals and fish, were isolated, and the willingness to pay for proposed factors was examined. The results showed that divers were willing to contribute towards all increases in reef community attributes, and were partially able to discriminate between them. Biodiversity was the most valued index, while fish abundance was the least favoured. These results, which demonstrate that visitors understand the fundamentals that constitute a coral reef community and value its diversity, may help direct conservation efforts undertaken in the design of marine reserves and pre-planned artificial reefs.
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Bazylev, V. V., P. A. Batrakov, D. M. Khadiev, A. A. Egorov, and N. A. Eremin. "Aortic root prosthesis with pericardial cusps "Russian conduit": A hydrodynamic experiment." Patologiya krovoobrashcheniya i kardiokhirurgiya 25, no. 4 (December 28, 2021): 97. http://dx.doi.org/10.21688/1681-3472-2021-4-97-105.
Повний текст джерелаАнотація:
<p><strong>Aim.</strong> The study aimed to compare the hydrodynamic characteristics and durability of the aortic root prosthesis with pericardial cusps with various options for the formation of commissures.</p><p><strong>Methods.</strong> Nine conduits with pericardial valves were formed according to the technique described by Ozaki. The prostheses were divided into 3 groups of 3 specimens each: group 1 — without additional reinforcing seams on the top of the commissure; group 2 — with an additional U-shaped seam without gasket; and group 3 — with an additional suture with an opposite pericardial gasket. The prostheses were fixed on a stand for hydrodynamic testing of artificial heart valves. The hydrodynamic characteristics of the prostheses were evaluated. The hydrodynamics of the frame biological prosthesis was used for comparison. After assessing the hydrodynamic parameters of the aortic root prostheses, their work durability was tested. Defects of the pericardial cusps were studied macroscopically.</p><p><strong>Results. </strong>Two samples from group 2 were withdrawn from testing ahead of schedule at around 11 × 10<sup>6</sup> cycles, which is approximately 3.5 months of normal heart function. The other prostheses remained competent and were removed for an examination at 32 × 10<sup>6</sup> cycles, which is approximately 9.6 months of normal heart function.</p><p><strong>Conclusion. </strong>The hydrodynamics of the aortic root prosthesis with pericardial valves was comparable to the hydrodynamics of the frame biological prosthesis. Additional U-shaped sutures in the commissure area of the pericardial cusps did not increase the functional durability of the aortic root prosthesis with pericardial leaflets and served as additional risk factors for leaflet perforation. Implantation of pericardial leaflets into a vascular graft resulted in a different distribution of dynamic stress compared to the original aortic valve neocuspidisation, which preserved the aortic root.</p><p>Received 8 July 2021. Revised 30 August 2021. Accepted 7 September 2021.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest:</strong> Authors declare no conflict of interest.</p><p><strong>Contribution of the authors<br /> </strong>Conception and study design: V.V. Bazylev, P.A. Batrakov<br /> Data collection and analysis: P.A. Batrakov, D.M. Khadiev, A.A. Egorov, N.A. Eremin<br /> Drafting the article: P.A. Batrakov<br /> Critical revision of the article: V.V. Bazylev, P.A. Batrakov<br /> Final approval of the version to be published: V.V. Bazylev, P.A. Batrakov, D.M. Khadiev, A.A. Egorov, N.A. Eremin<strong> </strong></p>
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Dutton, Gail. "Biologists Discovering the Value of Artificial Intelligence." BioScience 70, no. 9 (August 28, 2020): 729–35. http://dx.doi.org/10.1093/biosci/biaa086.
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Zhang, Shu. "Based on Artificial Neural Network Simulation of Alloy Finite Element." Advanced Materials Research 710 (June 2013): 739–42. http://dx.doi.org/10.4028/www.scientific.net/amr.710.739.
Повний текст джерелаАнотація:
Artificial neural networks are composed of interconnecting artificial neurons (programming constructs that mimic the properties of biological neurons). Artificial neural networks may either be used to gain an understanding of biological neural networks, or for solving artificial intelligence problems without necessarily creating a model of a real biological system. First modal analyses of microstructure defects are performed in ANSYS. Second the genetic algorithm is implemented in MATLAB to Calculate the Value of b and p. The last, The FEM analysis results are imported in ANSYS about the Stress distribution. The result presented in this paper is obtained using the Genetic Algorithm Optimization Toolbox.
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Guseva, Yulia, Alexander Korobov, Petr Tarasov, Alexey Vasilyev, and Oksana Gurkina. "Comparative analysis of muscle tissue amino acid composition of sturgeon breeded under natural and industrial conditions." IOP Conference Series: Earth and Environmental Science 937, no. 3 (December 1, 2021): 032041. http://dx.doi.org/10.1088/1755-1315/937/3/032041.
Повний текст джерелаАнотація:
Abstract The article presents comparative data on the chemical and amino acid analysis of the muscle tissue of sturgeons of the natural ichthyofauna of the Volgograd reservoir and those grown in a cage farm in the natural temperature regime of the 4th zone of fish farming in the Russian Federation using balanced feeding. The results obtained indicate the saturation of the muscle tissue of sturgeons consuming artificial feed with amino acids. The difference in nutrition is reflected in the biological value of meat. An important indicator of the biological value of a product is the qualitative and quantitative composition of muscle tissue amino acids. The natural nutrition of the Volgograd Reservoir does not fully satisfy the sturgeon’s need for protein nutrition. Industrial methods of cultivation make it possible to optimally organize biologically complete feeding of fish, which contributes to the maximum manifestation of their genetic potential and production of functional products.
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Blais, Jonatan, Sylvie Giroux, André Caron, Valérie Clément, and François Rousseau. "Development of Reference Materials for Noninvasive Prenatal Aneuploidy Testing by Massively Parallel Sequencing: A Proof-of-Concept Study." Journal of Applied Laboratory Medicine 4, no. 1 (July 1, 2019): 50–60. http://dx.doi.org/10.1373/jalm.2018.028100.
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Abstract Background Noninvasive prenatal aneuploidy testing (NIPT) represents the first large-scale clinical application of massively parallel sequencing technology. However, no NIPT reference material (RM) has yet been widely adopted, impeding the development of quality management systems and standardization. Developing an NIPT RM from a biological sample is complicated by the low concentration of cell-free DNA (cfDNA), which implies pooling specimens and frequent resampling. Methods We tested the feasibility of using DNA from immortalized cell lines of a woman and her aneuploid offspring to spike an artificial plasma matrix. Enzymatic fragmentation of extracted DNA was optimized to achieve fragment size profiles with a mode of 150 to 200 bp, similar to biological cfDNA. This synthetic material was compared with routine biological samples from pregnant women by a targeted NIPT assay in a multiplex sequencing run on a Proton platform. Results Sequencing statistics were similar between artificially prepared material and routine biological samples, as well as relative chromosomal representation, and no matrix effects could be detected. Estimate of fetal fraction (FF) was within the range of expected value, and aneuploidy detection statistic (z-score) was also comparable between both types of samples. Conclusions Artificial plasma spiked with DNA from cell lines of mother and offspring is a promising strategy for developing NIPT RM. This type of material would offer the advantage of a constant and stable composition, allowing for greater standardization of NIPT assays. Moreover, it preserves the parental relatedness used by targeted assay to estimate FF by identification of paternal alleles in single-nucleotide polymorphisms or other variable regions.
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Keinan, Alon, Ben Sandbank, Claus C. Hilgetag, Isaac Meilijson, and Eytan Ruppin. "Fair Attribution of Functional Contribution in Artificial and Biological Networks." Neural Computation 16, no. 9 (September 1, 2004): 1887–915. http://dx.doi.org/10.1162/0899766041336387.
Повний текст джерелаАнотація:
This letter presents the multi-perturbation Shapley value analysis (MSA), an axiomatic, scalable, and rigorous method for deducing causal function localization from multiple perturbations data. The MSA, based on fundamental concepts from game theory, accurately quantifies the contributions of network elements and their interactions, overcoming several shortcomings of previous function localization approaches. Its successful operation is demonstrated in both the analysis of a neurophysiological model and of reversible deactivation data. The MSA has a wide range of potential applications, including the analysis of reversible deactivation experiments, neuronal laser ablations, and transcranial magnetic stimulation “virtual lesions”, as well as in providing insight into the inner workings of computational models of neurophysiological systems.
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Dayhoff, Judith E. "Computational Properties of Networks of Synchronous Groups of Spiking Neurons." Neural Computation 19, no. 9 (September 2007): 2433–67. http://dx.doi.org/10.1162/neco.2007.19.9.2433.
Повний текст джерелаАнотація:
We demonstrate a model in which synchronously firing ensembles of neurons are networked to produce computational results. Each ensemble is a group of biological integrate-and-fire spiking neurons, with probabilistic interconnections between groups. An analogy is drawn in which each individual processing unit of an artificial neural network corresponds to a neuronal group in a biological model. The activation value of a unit in the artificial neural network corresponds to the fraction of active neurons, synchronously firing, in a biological neuronal group. Weights of the artificial neural network correspond to the product of the interconnection density between groups, the group size of the presynaptic group, and the postsynaptic potential heights in the synchronous group model. All three of these parameters can modulate connection strengths between neuronal groups in the synchronous group models. We give an example of nonlinear classification (XOR) and a function approximation example in which the capability of the artificial neural network can be captured by a neural network model with biological integrate-and-fire neurons configured as a network of synchronously firing ensembles of such neurons. We point out that the general function approximation capability proven for feedforward artificial neural networks appears to be approximated by networks of neuronal groups that fire in synchrony, where the groups comprise integrate-and-fire neurons. We discuss the advantages of this type of model for biological systems, its possible learning mechanisms, and the associated timing relationships.
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Portegys, Thomas E. "Generating an Artificial Nest Building Pufferfish in a Cellular Automaton Through Behavior Decomposition." International Journal of Artificial Intelligence and Machine Learning 9, no. 1 (January 2019): 1–12. http://dx.doi.org/10.4018/ijaiml.2019010101.
Повний текст джерелаАнотація:
A species of pufferfish builds fascinating circular nests on the sea floor to attract mates. This project simulates the nest building behavior in a cellular automaton using the morphognosis model. The model features hierarchical spatial and temporal contexts that output motor responses from sensory inputs. By considering the biological neural network of the pufferfish as a black box, and decomposing only its external behavior, an artificial counterpart can be generated. In this way a complex biological system producing a behavior can be filtered into a system containing only functions that are essential to reproduce the behavior. The derived system not only has intrinsic value as an artificial entity but also might help to ascertain how the biological system produces the behavior.
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HUANG, XIAO, and JUYANG WENG. "INHERENT VALUE SYSTEMS FOR AUTONOMOUS MENTAL DEVELOPMENT." International Journal of Humanoid Robotics 04, no. 02 (June 2007): 407–33. http://dx.doi.org/10.1142/s0219843607001011.
Повний текст джерелаАнотація:
The inherent value system of a developmental agent enables autonomous mental development to take place right after the agent's "birth." Biologically, it is not clear what basic components constitute a value system. In the computational model introduced here, we propose that inherent value systems should have at least three basic components: punishment, reward and novelty with decreasing weights from the first component to the last. Punishments and rewards are temporally sparse but novelty is temporally dense. We present a biologically inspired computational architecture that guides development of sensorimotor skills through real-time interactions with the environments, driven by an inborn value system. The inherent value system has been successfully tested on an artificial agent in a simulation environment and a robot in the real world.
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Liu, Chenglong, Yunchang Xin, Xiubo Tian, and Paul K. Chu. "Degradation susceptibility of surgical magnesium alloy in artificial biological fluid containing albumin." Journal of Materials Research 22, no. 7 (July 2007): 1806–14. http://dx.doi.org/10.1557/jmr.2007.0241.
Повний текст джерелаАнотація:
The objective of this study is to investigate the corrosion susceptibility of surgical AZ91 magnesium alloys in simulated body fluids (SBFs) consisting of bovine serum albumin (BSA) and acidic SBFs (pH 5) using electrochemical methods. The addition of BSA significantly moves the open-circuit potential toward a more positive value and suppresses the corrosion reaction. The corrosion resistance under the open-circuit conditions in the SBFs with 1 g/L BSA is approximately twice that in the SBFs. A higher BSA concentration decreases the corrosion susceptibility. In addition, the acidic SBF results in a higher alloy dissolution rate. The possible mechanisms are discussed.
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Manning, D. A. C. "Biological enhancement of soil carbonate precipitation: passive removal of atmospheric CO2." Mineralogical Magazine 72, no. 2 (April 2008): 639–49. http://dx.doi.org/10.1180/minmag.2008.072.2.639.
Повний текст джерелаАнотація:
AbstractSoils are the dominant terrestrial sink for carbon, containing three times as much C as above-ground plant biomass, and acting as a host for both organic and inorganic C, as soil organic matter and pedogenic carbonates, respectively. This article reviews evidence for the generation within the soil solution of dissolved C derived from plants and recognition of its precipitation as carbonates. It then considers the potential value of this process for artificially-mediated CO2 sequestration within soils. The ability of crops such as wheat to produce organic acid anions as root exudates is substantial, generating 70 mol/(y kg) of exuded C, equivalent to the plant's own ‘body weight’. This is still an order of magnitude less than measured C production from Icelandic woodlands (Moulton et al., 2000), which have no other possible source of C. Thus, there is apparently no shortage of available dissolved C, as bicarbonate in solution, and so the formation of pedogenic carbonates will be controlled by the availability of Ca. This is derived from mineral weathering, primarily of silicate minerals (natural plagioclase feldspars and pyroxenes; artificial cement and slag minerals). Within the UK, existing industrial arisings of calcium silicate minerals from quarrying, demolition and steel manufacture that are fine-grained and suitable for incorporation into soils are sufficient to account for 3 MT CO2 per year, compensating for half of the emissions from UK cement manufacture. Pursuing these arguments, it is shown that soils have a role to play as passive agents in the removal of atmospheric CO2, analogous to the use of reed beds to clean contaminated waters.
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Muhammed, Sadik. "Comparison of Some Biological Parameters between Young Grass Carp, Ctenopharyngodon idella (Valenciennes, 1884) fed on Artificial Diet and Alfalfa inEarthen Ponds at Basrah, Iraq." Biological and Applied Environmental Research 6, no. 1 (January 1, 2022): 1–13. http://dx.doi.org/10.51304/baer.2022.6.1.1.
Повний текст джерелаАнотація:
The current study aims to compare the relationships of some biological parameters of young grass carp, Ctenopharyngodon idella (Valenciennes, 1844) fed on artificial diet and alfalfa in earthen ponds. These parameters included length-weight relationship, relative length and weight of the alimentary canal, condition factor and survival rate. Results of lengthweight relationship showed that no significant differences (P>0.05) were recorded for the t-test for the ideal value of 3 for fishes fed on artificial diet or alfalfa plant. The condition factor of young grass carp fed on artificial diet ranged between 0.021 to 1.074, while for fishes fed on alfalfa plant was 0.023 to 1.270 for allometric and Fulton’s condition factor, respectively. Also, there was no significant difference (P>0.05) for fishes fed on both diets in all biological parameters, the relative length of the alimentary canal for fishes fed on artificial diet (1.65) and on alfalfa plant (1.69), while the relative weight of the alimentary canal were 0.0285 and 0.0218 for fishes fed on both diets, respectively. Results also showed that the Zihler coefficient were 7.43 and 7.62, respectively. The survival rate was 100% for both treatments.
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Al-Akhras, M. Ali H., K. Aljarrah, A. Al-Omari, H. M. Al-Khateeb, B. A. Albiss, K. Azez, and G. Makhadmeh. "Influence of extremely low energy radiation on artificial tissue: Effects on image quality and superficial dose." Spectroscopy 22, no. 5 (2008): 419–28. http://dx.doi.org/10.1155/2008/817132.
Повний текст джерелаАнотація:
The design and slicing technique of artificial soft tissue are presented. Artificial soft tissue has optical penetration properties similar to biological tissues. The soft tissues are made of agar dissolved in water as a transparent tissue (control) incorporated with scatter materials such as polystyrene microspheres and absorbers such as artificial dairy substitute, coffee mate (Carnation Co.). The radiation's interaction with 20 and 40 keV X-ray, and visible light (400–800 nm) with different types of tissue phantoms has been investigated. The half value layer (HVL), attenuation coefficient, energy density and penetration depth through the artificial tissues has been calculated. X-ray radiation depth show significant reduction in soft tissue incorporated with polystyrene microspheres. At extremely low energy (E), the half value layer decreases with increasing the energy, while the attenuation coefficient increase. The calculated values of the half value layers are in very good agreement with experimental results. The calculated values of effective linear attenuation coefficient, are found to be µeff(0.22–0.42). Significant reduction in superficial dose with clear image is found with 10 mm soft tissue filter used. These results suggests: possible enhancement in diagnostic imaging and reduction in excess dose to patients; artificial soft tissue can be used as filter substitute.
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Fateh, Muhammad Faisal, Aneela Zameer, Nasir M. Mirza, Sikander M. Mirza, and Muhammad Asif Zahoor Raja. "Biologically inspired computing framework for solving two-point boundary value problems using differential evolution." Neural Computing and Applications 28, no. 8 (January 19, 2016): 2165–79. http://dx.doi.org/10.1007/s00521-016-2185-z.
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Tian, Hongzhen, Kai Xu, Joaquim I. Goes, Qinping Liu, Helga do Rosario Gomes, and Mengmeng Yang. "Shoreline Changes Along the Coast of Mainland China—Time to Pause and Reflect?" ISPRS International Journal of Geo-Information 9, no. 10 (September 29, 2020): 572. http://dx.doi.org/10.3390/ijgi9100572.
Повний текст джерелаАнотація:
Shoreline changes are of great importance for evaluating the interaction between humans and ecosystems in coastal areas. They serve as a useful metric for assessing the ecological costs of socioeconomic developmental activities along the coast. In this paper, we present an assessment of shoreline changes along the eastern coast of mainland China from ~1990 to 2019 by applying a novel method recently developed by us. This method which we call the Nearest Distance Method (NDM) is used to make a detailed assessment of shorelines delineated from Landsat Thematic Mapper (TM) and Operational Land Imager (OLI) images. The results indicate a dramatic decline in natural shorelines that correspond to the rapid increase in the construction of artificial shorelines, driven by China’s economic growth. Of the entire coast of mainland China, the biggest change occurred along the Bohai Sea, where artificial shorelines expanded from 42.4% in ~1990 to 81.5% in 2019. Over this period, this study indicates that China lost > 60% of its biological shorelines, a trend that is especially worrisome because these include areas that were once biologically diverse and extremely rich. As anticipated, shoreline losses were greatest where regions of low economic value had been transformed to areas of higher economic value. Overall, this influence of human activities on shorelines in China is unprecedented. The repercussions of these changes on ecosystems, and the susceptibility of new shoreline developments to population growth and sea-level rise, need to be assessed urgently before additional changes are effected.
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Степанова, Э. Е., А. С. Постоялко, С. А. Сивак, С. С. Галицкая, А. П. Шкет, and Е. Г. Комаровская. "Minimally Invasive Technologies in Treatment of Secondary Mitral Regurgitation: Experience of MitraClip Device Implantation." Кардиология в Беларуси, no. 5 (November 19, 2021): 692–703. http://dx.doi.org/10.34883/pi.2021.13.5.003.
Повний текст джерелаАнотація:
Цель. Изучить клиническую эффективность и безопасность применения системы для эндоваскулярной пластики митрального клапана MitraClip у пациентов с вторичной митральной регургитацией (ВМР). Материалы и методы. На базе Республиканского клинического медицинского центра Управления делами Президента Республики Беларусь за период с июля 2018 по май 2021 г. выполнено 22 вмешательства с использованием системы MitraClip пациентам с сердечной недостаточностью (NYHA II-IV) и тяжелой митральной регургитацией (≥III степени). Всем больным проводили физикальное обследование, электрокардиографию, лабораторные исследования, трансторакальную и чреспищеводную эхокардиографию. Преобладали лица мужского пола (81,5%), старших возрастных групп (средний возраст 64,1±7,2) промежуточного и высокого риска по шкале EuroScore II с сопутствующими заболеваниями и кардиохирургическими вмешательствами в анамнезе. Вмешательство проводилось в рентгеноперационной под многокомпонентной анестезией с искусственной вентиляцией легких. Устройство вводилось чрескожно через правую бедренную вену. Позиционирование проходило под контролем трехмерной чреспищеводной эхокардиографии в реальном времени. Чреспищеводная эхокардиография использовалась для оценки адекватности захвата створок, остаточной МР и трансклапанного градиента. Результаты. У 95% пациентов после имплантации MitraClip резидуальная регургитация оценивалась как легкая (<II степени). 5 пациентам было имплантировано 1 устройство, 16 пациентам - 2, 1 пациентке - 3 клипсы с техническими сложностями (впоследствии потребовалась замена МК биологическим протезом). У 95% пациентов послеоперационный период протекал без осложнений. Средний койко-день составил 6 дней, из них 1 - в отделении анестезиологии и реанимации, что значительно меньше, чем после кардиохирургических операций. За период наблюдения (медиана 9,7±4,6 месяца) умерло 2 пациента (9%). У 100% пациентов существенно уменьшилась степень митральной регургитации, у 52,6% пациентов наблюдалось улучшение функционального класса СН. Заключение. Результаты исследования подтверждают безопасность и эффективность транскатетерной пластики МК с помощью системы MitraClip и позволяют рекомендовать данное вмешательство пациентам высокого риска с симптомной тяжелой МР. Purpose. To study the clinical efficiency and safety of the MitraClip system usage in endovascular mitral valve repair in patients with secondary mitral regurgitation (SMR). Materials and methods. On the base of the Republican Clinical Medical Center of the Administrative Department of the President of the Republic of Belarus, from July 2018 to May 2021, 22 interventions using the MitraClip system in patients with heart failure (NYHA II-IV) and severe mitral regurgitation (≥3 degree) were carried out. All patients underwent physical examination, electrocardiography, laboratory tests, transthoracic and transesophageal echocardiography. Males (81.5%) of senior age groups (mean age - 64.1±7.2) of intermediate and high risk according to the EuroScore II scale, with concomitant diseases and cardiac surgery in anamnesis prevailed. The intervention was carried out in the X-ray operating room under multicomponent anesthesia with artificial lung ventilation. The device was inserted percutaneously through the right femoral vein. Positioning was performed under the real-time 3D transesophageal echocardiography control. Transesophageal echocardiography was applied to assess the leaflet capture adequacy, residual mitral regurgitation, and transvalvular gradient. Results. After MitraClip implantation, in 95% of patients, the residual regurgitation was assessed as mild (degree <2). In 5 patients, 1 device was implanted, in 16 - 2, in 1 - three clips with technical problems (later, the MV replacement with a biological prosthesis was necessary). In 95% of patients, the postoperative period was without complications. The average bed-day was 6 days, 1 of which at the anesthesiology and intensive care departments, which is significantly less than after cardiac surgery. During the follow-up period (median - 9.7±4.6 months), 2 patients (9%) died. In 100% of patients, the mitral regurgitation degree decreased significantly; in 52.6% of patients, there was revealed the improvement of the HF functional class. Conclusion. The study results confirm the safety and efficiency of transcatheter mitral valve repair with the MitraClip system usage and let to recommend this intervention for high-risk patients with symptomatic severe MR.
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Brütt, Maximilian, and Christian Kaernbach. "On the Role of the Excitation/Inhibition Balance of Homeostatic Artificial Neural Networks." Entropy 23, no. 12 (December 14, 2021): 1681. http://dx.doi.org/10.3390/e23121681.
Повний текст джерелаАнотація:
Homeostatic models of artificial neural networks have been developed to explain the self-organization of a stable dynamical connectivity between the neurons of the net. These models are typically two-population models, with excitatory and inhibitory cells. In these models, connectivity is a means to regulate cell activity, and in consequence, intracellular calcium levels towards a desired target level. The excitation/inhibition (E/I) balance is usually set to 80:20, a value characteristic for cortical cell distributions. We study the behavior of these homeostatic models outside of the physiological range of the E/I balance, and we find a pronounced bifurcation at about the physiological value of this balance. Lower inhibition values lead to sparsely connected networks. At a certain threshold value, the neurons develop a reasonably connected network that can fulfill the homeostasis criteria in a stable way. Beyond the threshold, the behavior of the artificial neural network changes drastically, with failing homeostasis and in consequence with an exploding number of connections. While the exact value of the balance at the bifurcation point is subject to the parameters of the model, the existence of this bifurcation might explain the stability of a certain E/I balance across a wide range of biological neural networks. Assuming that this class of models describes the self-organization of biological network connectivity reasonably realistically, the omnipresent physiological balance might represent a case of self-organized criticality in order to obtain a good connectivity while allowing for a stable intracellular calcium homeostasis.
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Chandra, Yogesh, and Shikha Mishra. "Image Compression Techniques Using Artificial Neural Network." Journal of Advance Research in Computer Science & Engineering (ISSN: 2456-3552) 2, no. 3 (March 31, 2015): 87–105. http://dx.doi.org/10.53555/nncse.v2i3.498.
Повний текст джерелаАнотація:
This paper contain neural network bases on image compression techniques .The image compression is the application of the data compression on digital images. The main role of the image compression technique which is used to reduce the number of pixels and reduce the broadcast and transmission cost in efficient form and an artificial neural network is a computational structure which is stimulated by observed process in neural network of biological neuron in the brain. Image compression based on back propagation neural network with Liebenberg - marquardt algorithm and it is achieved by image is divided into number of blocks and select the one neural network for each block according to its complexity value. The Training algorithm and back propagation neural network is used to increase the performance and to decrease the convergence time and provide high compression ratio and low distortion. The neural network training process best for image compression and applications. Keywords - Artificial neural network, Back propagation neural network, image Compression, L-M algorithms:
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Ya, Xiong, and Min Jie Li. "Studies on the Biological Characteristics of Termitomyces Albuminosus Hypha." Advanced Materials Research 709 (June 2013): 810–13. http://dx.doi.org/10.4028/www.scientific.net/amr.709.810.
Повний текст джерелаАнотація:
Termitomyces albuminosus is a kind of local distinctive wild edible fungi in southwest of China. It is delicious, rich in nutrition and has high development and utilization value, but owing to the restrictions of growth environment, it can not be cultivated artificially. This article mainly studied on the biological characteristics of Termitomyces albuminosus Hypha, and found out the optimal carbon source, nitrogen source, growth factors and the C/N ratio that are suitable for the growth of Hypha of Termitomyces albuminosus .
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Che, Lin, Wenbiao Jin, Xu Zhou, Chenbo Cao, Wei Han, Changlei Qin, Renjie Tu, Yidi Chen, Xiaochi Feng, and Qilin Wang. "Biological Reduction of Organic Matter in Buji River Sediment (Shenzhen, China) with Artificial Oxygenation." Water 12, no. 12 (December 21, 2020): 3592. http://dx.doi.org/10.3390/w12123592.
Повний текст джерелаАнотація:
In this work, artificial oxygenation treatment (pure oxygen aeration or oxygen enriched water injection) combined with the introduction of exogenous microorganisms was employed to purify urban river sediment for the first time. Results showed that the developed in situ remediation strategy could increase the dissolved oxygen (DO) concentration and oxidation-reduction potential (ORP) value of the sediments. Benefiting from the increase of DO concentration, the bacterial diversity was enhanced. The highest removal efficiencies of organic matter were 18.4% and 22.3% through pure oxygen aeration and oxygen enriched water injection, respectively. More importantly, overlying water quality was not affected. By comparison, oxygen enriched water injection treatment could achieve better performance on sediment purification. Introducing exogenous microorganisms further reduced the organic matter content of the sediment. In short, the current work not only proposed a promising strategy for controlling urban river sediment pollution, but also provided novel insight for the understanding of river sediment containing highly concentrated organic matter.
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Yamakawa, Hiroshi. "Peacekeeping Conditions for an Artificial Intelligence Society." Big Data and Cognitive Computing 3, no. 2 (June 22, 2019): 34. http://dx.doi.org/10.3390/bdcc3020034.
Повний текст джерелаАнотація:
In a human society with emergent technology, the destructive actions of some pose a danger to the survival of all of humankind, increasing the need to maintain peace by overcoming universal conflicts. However, human society has not yet achieved complete global peacekeeping. Fortunately, a new possibility for peacekeeping among human societies using the appropriate interventions of an advanced system will be available in the near future. To achieve this goal, an artificial intelligence (AI) system must operate continuously and stably (condition 1) and have an intervention method for maintaining peace among human societies based on a common value (condition 2). However, as a premise, it is necessary to have a minimum common value upon which all of human society can agree (condition 3). In this study, an AI system to achieve condition 1 was investigated. This system was designed as a group of distributed intelligent agents (IAs) to ensure robust and rapid operation. Even if common goals are shared among all IAs, each autonomous IA acts on each local value to adapt quickly to each environment that it faces. Thus, conflicts between IAs are inevitable, and this situation sometimes interferes with the achievement of commonly shared goals. Even so, they can maintain peace within their own societies if all the dispersed IAs think that all other IAs aim for socially acceptable goals. However, communication channel problems, comprehension problems, and computational complexity problems are barriers to realization. This problem can be overcome by introducing an appropriate goal-management system in the case of computer-based IAs. Then, an IA society could achieve its goals peacefully, efficiently, and consistently. Therefore, condition 1 will be achievable. In contrast, humans are restricted by their biological nature and tend to interact with others similar to themselves, so the eradication of conflicts is more difficult.
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Irfan, Muhammad, Sharjeel Waqas, Ushtar Arshad, Javed Akbar Khan, Stanislaw Legutko, Izabela Kruszelnicka, Dobrochna Ginter-Kramarczyk, Saifur Rahman, and Anna Skrzypczak. "Response Surface Methodology and Artificial Neural Network Modelling of Membrane Rotating Biological Contactors for Wastewater Treatment." Materials 15, no. 5 (March 4, 2022): 1932. http://dx.doi.org/10.3390/ma15051932.
Повний текст джерелаАнотація:
Membrane fouling is a major hindrance to widespread wastewater treatment applications. This study optimizes operating parameters in membrane rotating biological contactors (MRBC) for maximized membrane fouling through Response Surface Methodology (RSM) and an Artificial Neural Network (ANN). MRBC is an integrated system, embracing membrane filtration and conventional rotating biological contactor in one individual bioreactor. The filtration performance was optimized by exploiting the three parameters of disk rotational speed, membrane-to-disk gap, and organic loading rate. The results showed that both the RSM and ANN models were in good agreement with the experimental data and the modelled equation. The overall R2 value was 0.9982 for the proposed network using ANN, higher than the RSM value (0.9762). The RSM model demonstrated the optimum operating parameter values of a 44 rpm disk rotational speed, a 1.07 membrane-to-disk gap, and a 10.2 g COD/m2 d organic loading rate. The optimization of process parameters can eliminate unnecessary steps and automate steps in the process to save time, reduce errors and avoid duplicate work. This work demonstrates the effective use of statistical modeling to enhance MRBC system performance to obtain a sustainable and energy-efficient treatment process to prevent human health and the environment.
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Gizinger, O. A. "The value of physiotherapeutic methods using low-intensity laser radiation in increasing the effectiveness of rehabilitation measures in persons who have had respiratory infections of viral and bacterial nature." Terapevt (General Physician), no. 2 (February 1, 2021): 44–50. http://dx.doi.org/10.33920/med-12-2102-05.
Повний текст джерелаАнотація:
Laser therapy, as one of the artificial therapeutic physical factors, has long been successfully used in medicine. Detailed analysis and study of the effect of monochromatic light on various biological objects, cells, organs and systems of the body made it possible to clarify the parameters of the therapeutic effect of the magnetic field, propose methods and algorithms for conducting procedures, expand the indications and clarify contraindications to the use of laser therapy.
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Shu, L. H. "A natural-language approach to biomimetic design." Artificial Intelligence for Engineering Design, Analysis and Manufacturing 24, no. 4 (October 25, 2010): 507–19. http://dx.doi.org/10.1017/s0890060410000363.
Повний текст джерелаАнотація:
AbstractThis paper summarizes various aspects of identifying and applying biological analogies in engineering design using a natural-language approach. To avoid the immense as well as potentially biased task of creating a biological database specifically for engineering design, the chosen approach searches biological knowledge in natural-language format, such as books and papers, for instances of keywords describing the engineering problem. Strategies developed to facilitate this search are identified, and how text descriptions of biological phenomena are used in problem solving is summarized. Several application case studies are reported to illustrate the approach. The value of the natural-language approach is demonstrated by its ability to identify relevant biological analogies that are not limited to those entered into a database specifically for engineering design.
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Song, Li, Gui Fang Jiang, Zhi Gang Xie, Qing Li, and Wu Quan Ding. "Experimental Study on the Landscape Combined Sewage Treatment Technology." Advanced Materials Research 864-867 (December 2013): 2654–58. http://dx.doi.org/10.4028/www.scientific.net/amr.864-867.2654.
Повний текст джерелаАнотація:
In this paper, artificial wetland systems, aeration tanks, rapid filter combined biological wastewater treatment process facilities for domestic sewage treatment. Test systems,TN treatment effect, are higher than the value of surface water quality standard GB3838-2002 in V class standards.Treatment effect to achieve the urban sewage treatment plant pollutant discharge standards GB18918-2002 a class of emission standards, the treatment system, low cost, easy management, stable operation.
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Xiong, Xiaofeng, Florentin Wörgötter, and Poramate Manoonpong. "Virtual agonist-antagonist mechanisms produce biological muscle-like functions." Industrial Robot: An International Journal 41, no. 4 (June 10, 2014): 340–46. http://dx.doi.org/10.1108/ir-11-2013-421.
Повний текст джерелаАнотація:
Purpose – The purpose of this paper is to apply virtual agonist–antagonist mechanisms (VAAMs) to robot joint control allowing for muscle-like functions and variably compliant joint motions. Biological muscles of animals have a surprising variety of functions, i.e. struts, springs and brakes. Design/methodology/approach – Each joint is driven by a pair of VAAMs (i.e. passive components). The muscle-like functions as well as the variable joint compliance are simply achieved by tuning the damping coefficient of the VAAM. Findings – With the VAAM, variably compliant joint motions can be produced without mechanically bulky and complex mechanisms or complex force/toque sensing at each joint. Moreover, through tuning the damping coefficient of the VAAM, the functions of the VAAM are comparable to biological muscles. Originality/value – The model (i.e. VAAM) provides a way forward to emulate muscle-like functions that are comparable to those found in physiological experiments of biological muscles. Based on these muscle-like functions, the robotic joints can easily achieve variable compliance that does not require complex physical components or torque sensing systems, thereby capable of implementing the model on small-legged robots driven by, for example, standard servo motors. Thus, the VAAM minimizes hardware and reduces system complexity. From this point of view, the model opens up another way of simulating muscle behaviors on artificial machines. Executive summary – The VAAM can be applied to produce variable compliant motions of a high degree-of-freedom robot. Only relying on force sensing at the end effector, this application is easily achieved by changing coefficients of the VAAM. Therefore, the VAAM can reduce economic cost on mechanical and sensing components of the robot, compared to traditional methods (e.g. artificial muscles).
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Sun, Peng, Xiaozi Liu, Yanli Tang, Wenzhi Cheng, Runlong Sun, Xinxin Wang, Rong Wan, and Mikko Heino. "The bio-economic effects of artificial reefs: mixed evidence from Shandong, China." ICES Journal of Marine Science 74, no. 8 (May 24, 2017): 2239–48. http://dx.doi.org/10.1093/icesjms/fsx058.
Повний текст джерелаАнотація:
Abstract Artificial reefs are used to protect coastal habitats and rebuild fisheries. This engineering approach to fisheries management has gained popularity in many coastal areas, including China. In Shandong province alone, over USD 50 million were invested in artificial reefs during 2005–2013. Have artificial reefs achieved their biological and economic objectives? We compared reef and control sites in terms of catch and value per unit effort and average body length across species, based on surveys carried out during 2012–2013. We found that in aggregate, with all fish and invertebrates combined, artificial reefs did not improve the overall catches or revenues. Instead, seasonal fluctuations were prominent. However, when we allow for species-specific differences and focus on the common fish species, we find that an artificial reef can increase the catch and value per unit effort on average by approximately 40% compared to the control sites. The difference between these contrasting results occurs because some of the dominant species that comprise the bulk of the catches did not benefit from the reef, while many of the less dominant ones did so. This underlines the importance of being specific about what is meant by “benefiting fisheries” when evaluating artificial reefs, as well as when the objectives of reef projects are formulated in the first place. The positive effects of artificial reefs can be caused by the reefs themselves and by their influence on fishing patterns. Our study was not designed to separate these effects but we suggest that in Shandong, restrictions on fishing access may have been as important as the presence of the reef itself.
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Mulder, Sander. "French Biological Philosophy of Technology as a Candidate Perspective Furthering Design Methodology." Proceedings of the Design Society: International Conference on Engineering Design 1, no. 1 (July 2019): 1493–502. http://dx.doi.org/10.1017/dsi.2019.155.
Повний текст джерелаАнотація:
AbstractA first exploration is conducted to what the French biological philosophy of technology perspective has to offer to the field of design methodology. If this French perspective is combined with contemporary speculative pragmatism a generative design methodology emerges offering novelty in what is sensed as important in a design situation. Within this perspective, drawing upon the late French philosopher Gilbert Simondon, technical objects have their own mode of existence and their own trajectory of development apart from human intention.Designers working with such a generative design methodology follow the constitutive value of openness and attune to the regulative value of techno-aesthetic judgments. By way of a 'vignette+', a paradigmatic example from a real case, a more encompassing argument is made towards design situations where a sophisticated machine is 'inserted' into a domestic setting.The example taken is the use of an artificial kidney machine in a domestic setting and the development of a novel machine with a design team. Four aspects were sensed as important in the unfolding design situation and directions for further research are discussed.
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Gorshkova, Yulia, Marcela-Elisabeta Barbinta-Patrascu, Gizo Bokuchava, Nicoleta Badea, Camelia Ungureanu, Andrada Lazea-Stoyanova, Mina Răileanu, et al. "Biological Performances of Plasmonic Biohybrids Based on Phyto-Silver/Silver Chloride Nanoparticles." Nanomaterials 11, no. 7 (July 12, 2021): 1811. http://dx.doi.org/10.3390/nano11071811.
Повний текст джерелаАнотація:
Silver/silver chloride nanoparticles (Ag/AgClNPs), with a mean size of 48.2 ± 9.5 nm and a zeta potential value of −31.1 ± 1.9 mV, obtained by the Green Chemistry approach from a mixture of nettle and grape extracts, were used as “building blocks” for the “green” development of plasmonic biohybrids containing biomimetic membranes and chitosan. The mechanism of biohybrid formation was elucidated by optical analyses (UV–vis absorption and emission fluorescence, FTIR, XRD, and SAXS) and microscopic techniques (AFM and SEM). The aforementioned novel materials showed a free radical scavenging capacity of 75% and excellent antimicrobial properties against Escherichia coli (IGZ = 45 mm) and Staphylococcus aureus (IGZ = 35 mm). The antiproliferative activity of biohybrids was highlighted by a therapeutic index value of 1.30 for HT-29 cancer cells and 1.77 for HepG2 cancer cells. At concentrations below 102.2 µM, these materials are not hemolytic, so they will not be harmful when found in the bloodstream. In conclusion, hybrid systems based on phyto-Ag/AgClNPs, artificial cell membranes, and chitosan can be considered potential adjuvants in liver and colorectal cancer treatment.
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Liu, Xiao, and Lei Shi. "Fuzzy C-Mean Clustering Image Segmentation Algorithm Research for Sport Graphics Based on Artificial Life." Applied Mechanics and Materials 263-266 (December 2012): 2207–10. http://dx.doi.org/10.4028/www.scientific.net/amm.263-266.2207.
Повний текст джерелаАнотація:
In this paper, linking with the basic principle of FCM (Fuzzy c-means clustering) algorithm, on the basis of theory research, a method of the cluster analysis of FCM based on artificial life is proposed. The artificial life approach is promising in image processing because it is inherently parallel and coincides with the self-governing biological process. Firstly, the approximate optimal solution obtained by the FCM algorithm is taken as the original value, then combined with intensity-texture-position feature space in order to produce connected regions shown in the image, the final segmentation result is achieved at last. The experiment results prove that in the view of the sport image segmentation, this algorithm provides fast segmentation with high perceptual segmentation quality.
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Bella, Fitria Renata, Prihartini Widiyanti, and Aminatun. "The Effect of Glycerol Concentration on Biocomposite Bacterial Cellulose-Chitosan Characterization as Dura Mater Artificial." Journal of Biomimetics, Biomaterials and Biomedical Engineering 45 (May 2020): 40–48. http://dx.doi.org/10.4028/www.scientific.net/jbbbe.45.40.
Повний текст джерелаАнотація:
Bacterial cellulose and chitosan have been widely developed for biomaterial applications, one of which is used as a dura mater artificial. In designing dura mater artificial, there are several criteria that must be met, one of which is mechanical that can be seen through tensile strength and elongation value. In previous study, the mechanical properties of biocomposite bacterial cellulose-chitosan still too rigid and did not meet the standard. This research was conducted to determine the effect of the addition of glycerol concentration to the physical and biological of bacterial cellulose-chitosan membrane. Bacterial cellulose membranes with the addition of glycerol concentration of 0%; 0,25%; 0,5% and 0,75% were dried with oven and immersed for 6 hours in 0.5% chitosan solution. Characterization was performed by functional group, morphology, tensile strength, swelling, degradation and cytotoxicity test. Based on the results, it can conclude that biocomposite bacterial cellulose-chitosan-glycerol showed suitable characteristics as a dura mater artificial.
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Dabuzova, G. S., P. A. Aligazieva, K. M. Kebedov, S. K. Omarov, and I. M. Abdulaev. "Functional dry-cured sausage production technology." IOP Conference Series: Earth and Environmental Science 979, no. 1 (February 1, 2022): 012052. http://dx.doi.org/10.1088/1755-1315/979/1/012052.
Повний текст джерелаАнотація:
Abstract One of the new directions for the modern meat processing industry is the production of functional meat products. The development of functional dry-cured sausages is of no small importance in the nutrition of the population, they have a high biological, nutritional value, gastronomic quality, presentation, have a positive effect on the human body, since they are made from natural raw materials and ingredients without artificial additives, and therefore are intended for mass production, to the consumer.