383 research outputs found

    Using artificial neural network for forward kinematic problem of under-constrained cable robots

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    Cable-Driven Parallel Robot has many advantages. However, the problems of cable collision between each other and environment, the lack of proper structure and non-positive cable tension prevent the spread of them. In this work, a neural network (NN) model of under constrained cable robots is presented with external forces applied to the end-effector (EE) for computing the position of it. As in under-constrained robot’s kinematics and statics are innately coupled together, and they contemporaneously should be considered the forward kinematic problem of the robot change to an optimization problem. This approach does not require pre-knowledge of the uncertainties upper bounds and linear regression form of kinematic and dynamic models. Moreover, to ensure that all cables remain in tension, proposed control algorithm benefit the internal force concept in its structure. The main contribution of this paper has three goals. First, a method is used toward kinematic problem of the under constrained cable robot modeling using four bar linkage kinematic concept, which could be used in online control approaches for real-time purposes. Second, in order to track the position of end-effector, an online PD controller is designed by the three error criteria methods such as IAE, ISE and ITSE. Finally, as the third contribution, NN control approach is applied in order to validate the model. A model is created based on the robot’s geometry and dynamic to solve the forward kinematics problem. So, the forward kinematic problem is solved offline and used online. Moreover, an analysis of workspace is performed which discovers that the solution of the forward kinematic problem of the under-constrained cable robots is unique in this case. In addition, a modified local linear model tree algorithm for nonlinear system modelling are proposed. The results show the effectiveness of the proposed approach in modeling the under constrained cable robot

    Respecting the Spiritual Beliefs of Patients from the Perspective of Nurses: A Qualitative Study

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    Introduction: Hospitalized patients have different religious and worship needs. Understanding these needs and planning care in order to meet these needs are essential to performing holistic care. The aim of the present study was to explain the worship and religious needs of patients from the perception of clinical nurses. Method: This was a qualitative study with content analysis approach. In total, 23 nurses of diverse age and gender, and work experience at different wards and in different posts, were selected with purposeful sampling method and participated in the study. Data were collected through in-depth and semi-structured interviews. The data analysis method used in this study was content analysis based on constant comparative analysis. Results: Data analysis revealed the main theme to be respect for beliefs and values. Subthemes were honoring the family, commemorating religious rituals, recognizing values, and having faith. Conclusion: Cultural, religious, and ethnic backgrounds have an important impact on health care and on the way of understanding decisions. Nurses will be able to promote physical, spiritual, and moral health of patients and their family by deepening the human dimensions and creating a relationship based on respect toward their religious practices. Keywords: Religious rituals, Respect for beliefs, Content analysis, Honoring the family, Fait

    A comparative study about the impact of sensory stimulation performed by family members and nurses on vital signs of patients at ICU: A randomized clinical trial

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    Some studies have shown the effects of sensory stimulation on vital signs of patients at intensive care unit (ICU). However, little knowledge is available about family role compared to the role of nursing staff in this issue and current results are controversial. The aim of this study is to compare the impact of sensory stimulation performed by family members and nurses on vital signs of patients at ICU. In this study, 9669 patients were categorized into two intervention groups and one control group by stratified block randomization method. Dyang sensory stimulation was provided by family members and nursing staff. No intervention was performed for control group. Sensory stimulation was performed 2 hours a day for 6 consecutive days. The vital signs were assessed 5 minutes before and 30 minutes after intervention. Data analysis was performed by ANCOVA, ANOVA and repeated measures. The results showed that there was significant difference between the experimental groups in terms of vital signs before and after the intervention (p<0.001). Of this aspect, family group was the best, nursing group was the second and control group was the last group in classification. The effect of sensory stimulation on vital signs of comatose patients was greater when provided by family members

    Hormone Profiles and Antioxidant Activity of Cultivated and Wild Tomato Seedlings under Low-Temperature Stress

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    Low temperature is a major limiting factor for the growth and reproduction of some plant species, such as tomato. So far, few studies have been conducted on the effects of low temperature, and the mechanisms of plants' response to this type of stress is not fully clear. In the current study, the effects of low, nonfreezing temperature (10 °C for three days) on the hormone content, antioxidant activity, and expression patterns of cold-related genes in the leaves of cold-tolerant species (Solanum habrochaites Accession 'LA1777′) and cold-susceptible species (Solanum lycopersicum cultivar 'Moneymaker') were investigated. Low temperature increased the abscisic acid (ABA) content in both tomato species, while the content of zeatin-type cytokinins (ZT) increased in the cold-tolerant species. However, the content of indole-3-acetic acid (IAA) and gibberellic acid (GA) reduced in response to low temperature in susceptible species. Accordingly, cytokinin (CK) is identified as an important hormone associated with low-temperature stress in tomato. In addition, our results indicate that the C-repeat/DRE binding factor 1 (CBF1) gene is less induced in response to low temperature in tomato, although transcription of the inducer of CBF expression 1 (ICE1) gene was upregulated under low temperature in both tomato species. It seems that ICE1 may modulate cold-regulated (COR) genes in a CBF-independent way. In addition, in response to low temperature, the malondialdehyde (MDA) level and membrane stability index (MSI) increased in the susceptible species, indicating that low temperature induces oxidative stress. Additionally, we found that glutathione peroxidase is highly involved in reactive oxygen species (ROS) scavenging induced by low temperature, and antioxidants are more induced in tolerant species. Overall, our results suggest that sub-optimal temperatures promote oxidative stress in tomato and CK is introduced as a factor related to the response to low temperature that requires deeper attention in future breeding programs of tomato

    Chlorido[1-(2-eth­oxy­phen­yl)3-(4-nitro­phen­yl)triazenido]mercury(II)

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    In the title compound, [Hg(C14H13N4O3)Cl], the HgII atom is four-coordinated by one O atom and two N atoms from a tridentate 1-(2-eth­oxy­phen­yl)-3-(4-nitro­phen­yl)triazenide ligand and one terminal chloride ion in a distorted square-planar geometry. In the crystal structure, the mononuclear complexes are linked into pairs through C—H⋯O and C—H⋯Cl hydrogen bonds as well as π–π and C—H⋯π stacking inter­actions. In addition, weak Hg–μ6-arene π-inter­actions [mean distance of 3.667 (2) Å] are present between these dimers. The π–π stacking inter­actions are between aromatic rings with a centroid–centroid distance of 3.884 (2) Å. Moreover, edge-to-face inter­actions are present between eth­oxy CH groups and aromatic rings with H⋯π distances of 2.81 Å

    Light at Night Exposure Effects Differentiation and Cell Cycle in Rat Liver with Autonomic Nervous System Denervation

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    Introduction: Exposure to the artificial light at night (LAN) effect human health and causes several functional modification in body. Obesity, diabetes, and hormonal changes are reported after LAN in humans. Aim of this study is highlighting critical features of gene expression changes in liver of rats which are received autonomic nervous system.Methods: Liver gene expression profiles of 5 male Wistar rats that were received a sympathetic plus parasympathetic hepatic denervation and 1 hour expose light at night (LAN) from Gene Expression Omnibus (GEO) are compared with controls. The significant differentially expressed genes (DEGs) are screened by protein-protein interaction (PPI) network analysis STRING database (an application of Cytoscape software). CuleGO and CleuDedia the two applications of Cytoscape software were used for more analysis. Results: Among 250 DEGs, 173 genes characterized genes with fold change more than 2 plus 100 added relevant genes were included in the PPI network. Analysis of the main connected component (MCC) led to introduce 15 hubs and 15 bottlenecks. CCT2, COPS7A, KAT2A, and ERCC1were determined as hub-bottlenecks. Among hubs and bottlenecks, DHX15, KAT2A, CCT2, HSP90AB1, CCNE1, DHX16, LSM2, WEE1, CWC27, BAZ1B, RAB22A, DNM2, and DHX30 were linked to the each other’s by various kinds of actions. CCT2 and KAT2A, the two hub-bottlenecks are included in the interacted genes in the action map. Four classes of biological terms including negative regulation of non-motile cilium assembly, negative regulation of transforming growth factor beta activation, alpha-tubulin acetylation, and histamine-induced gastric acid secration were identified as the critical involved biochemical pathways and biological processes.Conclusion: Several essential functions as like differentiation, cell cycle, ribosome assembly, and splicing are affected by LAN in rat liver with autonomic nervous system denervation.

    The POLG Polyglutamine Tract Variants in Iranian Patients with Multiple Sclerosis

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    How to Cite This Article: Khatami M, Heidari MM, Mansouri R, Mousavi F. The POLG Polyglutamine Tract Variants in Iranian Patients with Multiple Sclerosis. Iran J Child Neurol. 2015 Winter; 9(1):37-41.AbstractObjectiveMultiple Sclerosis (MS) is a common disease of the central nervous system. The interaction between inflammatory and neurodegenerative processes typically results in irregular neurological disturbances followed by progressive disability.Mitochondrial dysfunction has been implicated in neurodegenerative disorders. The DNA polymerase-gamma (POLG) gene, which encodes the catalytic subunit of enzyme responsible for directing mtDNA replication, contains a poly glutamine tract (poly-Q) in the N-terminal, encoded by a CAG sequence in exon 2.Materials &amp; MethodsWe analyzed the POLG trinucleotide repeats in 40 Iranian patients with MS (27 females and 13 males with an age range of 18–55); and 47 healthy age, gender, and ethnic matched controls were chosen by PCR-SSCP analysis. ResultsOur results indicated that the most common allele in patients had 10 consecutive CAG repeats (10Q). Other alleles of 11and 12 trinucleotide repeats were detected.We did not find any difference between the CAG repeat length distribution in controls and MS patients.ConclusionNo correlation was observed in the POLG gene CAG repeat with pathogenesis of MS, but it looks that other point mutations in POLG gene may have an important role in the disease’s pathogenesis and produced more significant results.ReferencesBaranzini SE. Revealing the genetic basis of multiple sclerosis: are we there yet? Curr Opin Genet Dev. 2011 Jun; 21(3):317-24.Hoffjan S, Akkad DA. The genetics of multiple sclerosis: an update 2010. Mol Cell Probes. 2010 Oct; 24(5):237-43.Disanto G, Berlanga AJ, Handel AE, Para AE, Burrell AM, Fries A, et al. Heterogeneity in multiple sclerosis: scratching the surface of a complex disease. Autoimmune Dis. 2010; 2011:932351.International Multiple Sclerosis Genetics C, Wellcome Trust Case Control C, Sawcer S, Hellenthal G, Pirinen M, Spencer CC, et al. 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