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In the current paper we provide a proof of NP-completeness for the Cell Formation Problem (CFP) with the fractional grouping efficacy objective function. First the CFP with a linear objective function is considered. Following the ideas of Pinheiro et al. (2016) we show that it is equivalent to the Bicluster Graph Editing Problem (BGEP), which is known to be NP-complete due to the reduction from the 3-Exact 3-Cover Problem – 3E3CP (Amit, 2004). Then we suggest a polynomial reduction of the CFP with the linear objective to the CFP with the grouping efficacy objective. It proves the NP-completeness of this fractional CFP formulation. Along with the NP-status our paper presents important connections of the CFP with the BGEP and 3E3CP. Such connections could be used for "transferring" of known theoretical properties, efficient algorithms, polynomial cases, and other features of well-studied graph editing and exact covering problems to the CFP. [ABSTRACT FROM AUTHOR]

Photogalvanic effect was studied in photogalvanic cells containing EDTA as reductant, new methylene blue, and safranine O as photosensitizer. The photopotential and photocurrent generated were 740 mV and 110 μA, respectively. The observed conversion efficiency was 0.4442% and the maximum output (power) of cell was 81.4 μW. The photogalvanic cell can be used for 95 min in the dark due to the storage capacity of the cell. The effects of various parameters on the electrical output of the cell were observed. The mechanism of generation of the photocurrent in these photogalvanic cells has also been proposed. [ABSTRACT FROM AUTHOR]

This paper details the content and structure of the folk concept of life, and discusses its relevance for scientific research on life. In four empirical studies, we investigate which features of life are considered salient, universal, central, and necessary. Functionings, such as nutrition and reproduction, but not material composition, turn out to be salient features commonly associated with living beings (Study 1). By contrast, being made of cells is considered a universal feature of living species (Study 2), a central aspect of life (Study 3), and our best candidate for being necessary for life (Study 4). These results are best explained by the hypothesis that people take life to be a natural kind subject to scientific scrutiny. [ABSTRACT FROM AUTHOR]

In this paper, a new mobile robot mapping algorithm inspired from the functionality of hippocampus cells is presented. Place cells in hippocampus can store a map of the environment. This model fuses odometry and vision data based on dimensionality reduction technique, hierarchically. These two types of data are first fused and then considered as inputs to the place cell model. Place cells do the clustering of places. The proposed Place cell model has two types of inputs: Grid cells input and input from the lateral entorhinal cortex (LEC). The LEC is modelled based on the dimension reduction technique. Therefore, the data that causes locations different to be inserted into the place cell from this layer. Another contribution is proposing a new unsupervised dimension reduction method based on k-means. The method can find perpendicular independent dimensions. Also, the distance of cluster centres found in these dimensions is maximised. The method was compared with LDA and PCA in standard functions. Although LDA is a supervised method, the result showed that the proposed unsupervised method outperformed. To evaluate the place cells model, sequences of images collected by a mobile robot was used and similar results to real place cells achieved. [ABSTRACT FROM AUTHOR]

CircZNF609 (cZNF609) is previously revealed as an essential mediator in oxidative stress. This paper determined the role of cZNF609 in skin oxidative damage to evaluate its importance in pressure ulcer. HaCaT cells treated by H2O2 were considered as a cell model of pressure ulcer. The role of cZNF609 in the model was checked by conducting CCK-8 assay, FITC-PI double-staining, ROS detection and Western blot. The downstream gene and signalling of cZNF609 were studied by utilizing qRT-PCR and Western blot. HaCaT cells were remarkably damaged by H2O2, as evidenced by the viability loss, apoptosis and ROS generation. It was coupled with the elevated expression of p53, p16, Bax and the activated forms of caspase-3 and PARP. Meanwhile, cZNF609 was high-expressed in response to H2O2. The oxidative stress driven by H2O2 was alleviated by transfection with cZNF609 specific siRNA. Further, the anti-antioxidant impacts of cZNF609 silence were impeded by miR-145 silence. The inhibition of JNK and p38MAPK pathways induced by cZNF609 silence was impeded by miR-145 silence. The protective function of cZNF609 silence in H2O2-injured HaCaT cells was revealed in vitro. Silence of cZNF609 exhibited its impact possibly through regulating miR-145, and JNK and p38MAPK pathways. [ABSTRACT FROM AUTHOR]

Prolyl hydroxylase domain proteins (PHD2) is an oxygen sensor that is able to induce hypoxia-inducible factor-α (HIF-α) degradation under normoxic condition. The present paper designed to reveal the function of PHD2 in hepatocellular carcinoma (HCC) cells proliferation, migration and invasion. qRT-PCR and Western blot were carried out to see the expression of PHD2 in HCC tissues and cell lines. PHD2 expression in Huh7 and HepG3B cells was overexpressed or suppressed by transfection and then the changes of cell proliferation, migration and invasion were detected by CCK-8 assay, transwell assay and Western blot. PHD2 was highly expressed in HCC tissues and cell lines (Huh7, Hep3B, SK-HEP-1, HCCLM3 and MHCC97) as relative to para-cancerous non-tumour tissues and a normal hepatocyte line MIHA. PHD2 overexpression promoted Huh7 and Hep3B cells viability, migration and invasion. Meanwhile, CyclinD1, c-Myc, MMP-2, MMP-9 and Vimentin were up-regulated, while p53 was down-regulated by PHD2 overexpression. PHD2 silence led to a contrary impact. Further, PHD2 overexpression up-regulated Ras and Raf expression and induced phosphorylation of MEK, ERK, JAK1 and STAT3. PHD2 exhibited pro-tumour functions in HCC cells. PHD2 promoted HCC possibly through Ras/Raf/MEK/ERK and JAK1/STAT3 pathways. PHD2 is highly expressed in HCC tissue and cell lines; PHD2 promotes the proliferation of Huh7 and HepG3B cells; PHD2 enhances Huh7 and HepG3B cells migration and invasion; PHD2 activates Ras/Raf/MEK/ERK and JAK1/STAT3 signalling. [ABSTRACT FROM AUTHOR]

In a number of adult tissues, Nestin-positive stem cells/progenitors have been identified and shown to be involved in maintenance and remodeling. Various studies have shown that under stressful conditions, quiescent Nestin-positive progenitor cells are activated. Thereby, they migrate to their target location and differentiate into mature cells. In the current paper, we discuss if Nestin-positive progenitors in the hippocampus and adrenal gland belong to unique cell populations that are responsive to stress. Furthermore, we speculate about the mechanism behind their activation and the clinical importance of this stress-response. [ABSTRACT FROM AUTHOR]

The article presents information on the results of several research on virology. It mentions that the cellular receptor which is responsible for the entry of hemorrhagic fever arenaviruses is the transferrin receptor 1 (TfR1). It says that the cell count is unlikely to return to a normal level if highly active antiretroviral therapy (HAART) is started at lower CD4+ counts.

The industrialization of the agricultural sector has significantly increased the use of chemicals such as pesticides. Therefore, exposure to them is unavoidable, which makes it necessary to assess their safety for humans at actual exposure doses. This paper aims to determine toxicity of three types of pesticides toward human immune cells (HL-60 and U-937): glyphosate (GLY), deltamethrin (DEL), and chlorothalonil (CHL). Cell viability, membrane integrity, inflammation induction, and antioxidant activity were evaluated to determine differences in cellular response to the tested plant protection agents. In experimental models, all tested substances caused increased mortality of cells after only 24 h. Cell membrane damage was recorded under DEL and CHL influences. The largest disintegration of the cell membrane was due to the action of 100 μg/mL DEL for U-937 and CHL at 1 μg/mL for HL-60. GLY at a concentration of 3,600 μg/mL caused significant peroxidation of U-937 cells' lipids. CHL-induced inflammation in both types of cells tested. DEL and GLY also induced antioxidant activity in cells. These results lead to the conclusion that the tested pesticides act cytotoxically to the cells of the human immune system in doses to which both farmers and consumers are exposed. [ABSTRACT FROM AUTHOR]

The widespread application of triazole fungicides makes people attach great concern over its adverse effects in mammalian. In this paper, cytotoxic effects of triazole alcohol fungicides (TAFs) were assessed on human HeLa, A549, HCT116 and K562 cells, and the potential mechanism of TAFs cytotoxicity was studied preliminarily. Results showed that TAFs had cytotoxicity on human cells with different level and cytotoxic selectivity. TAFs cytotoxicity was resonated with a typical hormetic biphasic dose action that produced a complex pattern of stimulatory or inhibitory effects on cell viability. Among the five TAFs, diniconazole revealed a widest range of cytotoxicity to inhibit the viability of the adherent and the suspension cells, causing HeLa cells shrinkage, A549 cells shrunken, and K562 cells collapse, and showed stronger cytotoxicity than hexaconazole. Moreover, the involvement of ROS generation in the cytotoxicity of TAFs on human cells was observed, and the apoptosis of HeLa cells and the formation of apoptotic body in K562 cells induced by diniconazole were characterized. The results indicated the cytotoxicity of TAFs with different structures on human cells was depended on their own property and cell specificity, K562 cells were the most susceptible to TAFs and diniconazole was the strongest toxic. [ABSTRACT FROM AUTHOR]

This paper presents a case study of the Earth Liberation Front (ELF), based on interviews of the group's former affiliates. It examines the role of credit claims in organizing this underground leaderless resistance group's activity. In addition to the external signaling functions of credit claims—demonstrating capability, issuing demands, and soliciting public support—credit claims serve a movement-building role in the ELF. By issuing credit claims in "aboveground" fora that other cells are known to read, ELF cells with no direct links are able to communicate information to one another. Credit-claiming communiqués serve four organizing functions for the ELF. They constitute the ELF underground as an imagined community, recruit new cells, set agendas for future actions, and enforce operational standards of behavior via an informal "peer review" process. This study of the ELF suggests broader insights, including possible organizing techniques that may be observed in white supremacist and Islamist cases. [ABSTRACT FROM AUTHOR]

DNA damage can be generated in multiple ways from genotoxic and physiologic sources. Genotoxic damage is known to disrupt cellular functions and is lethal if not repaired properly. We compare the transcriptional programs activated in response to genotoxic DNA damage induced by ionizing radiation (IR) in abl pre-B cells from mice deficient in DNA damage response (DDR) genes Atm, Mre11, Mdc1, H2ax, 53bp1, and DNA-PKcs. We identified a core IR-specific transcriptional response that occurs in abl pre-B cells from WT mice and compared the response of the other genotypes to the WT response. We also identified genotype specific responses and compared those to each other. The WT response includes many processes involved in lymphocyte development and immune response, as well as responses associated with the molecular mechanisms of cancer, such as TP53 signaling. As expected, there is a range of similarity in transcriptional profiles in comparison to WT cells, with Atm-/- cells being the most different from the core WT DDR and Mre11 hypomorph (Mre11A/A) cells also very dissimilar to WT and other genotypes. For example, NF-kB-related signaling and CD40 signaling are deficient in both Atm-/- and Mre11A/A cells, but present in all other genotypes. In contrast, IR-induced TP53 signaling is seen in the Mre11A/A cells, while these responses are not seen in the Atm-/- cells. By examining the similarities and differences in the signaling pathways in response to IR when specific genes are absent, our results further illustrate the contribution of each gene to the DDR. The microarray gene expression data discussed in this paper have been deposited in NCBI's Gene Expression Omnibus (GEO) () and are accessible under accession number GSE116388. [ABSTRACT FROM AUTHOR]

The paper presents four topics dealing with phenomena induced by elastic thermal stresses acting in an isotropic multi-particle-matrix system to represent a model system applicable to real multi-phase materials of a precipitation-matrix type. The isotropic multi-particle-matrix system consists of periodically distributed spherical particles in an infinite matrix to be imaginarily divided into cubic cells containing a central spherical particle. Formulae for the thermal stresses to be investigated within the cubic cell represents functions of the particle volume fraction v and the particle radius R. The thermal stresses originate during a cooling process as a consequence of the difference αm - αp in the thermal expansion coefficients αm and αp of the matrix and the particle, respectively. Additionally, such temperature range is considered within which the multi-particle-matrix system exhibits elastic deformations regarding the yield stress and the particle-matrix boundary adhesion strength. Analytical fracture mechanics to represent the first topic of this paper results from the determination of a curve integral of the thermal-stress induced elastic energy density. The curve elastic energy density results in the determination of the critical particle radii Rpc and Rmc as reasons of the crack initiation in the spherical particle and the matrix for αm - αp < 0 and αm - αp > 0, respectively. Consequently, the crack propagation to follow the crack initiation is a consequence of the particle radius R > Rqc (q = p, m). Finally, a shape of the crack in a plane perpendicular to the direction of the crack propagation in the particle (q = p) and the matrix (q = p) is described by the function fq related to the ideal-brittle components. With regard to the crack initiation, the analytical determination of the radius Rqc is considered for any multi-phase materials of a precipitation-matrix type. With regard to the crack propagation, the analytical determination of the function fq along with an analysis concerning the crack dimension and directions of the crack propagation is considered for ceramic multi-phase materials which are generally assumed to be ideal-brittle. The thermal stresses induce resistance against compressive or tensile mechanical loading for αm - αp > 0 or αm - αp < 0, respectively. The analytical determination of the resistance results from the elastic energy gradient to represent the second topic of this paper. Derived by two equivalent mathematical techniques, the gradient within the cubic cell is defined as a surface integral of the thermal-stress induced elastic energy density. Consequently the 'surface' elastic energy density results in the analytical determination of the system strengthening to represent the third topic of this paper. Representing the fourth topic of this paper, an analytical model of stresses originating in isotropic crystalline lattices are derived. The stresses in the lattices are a consequence of the presence of a central substitutive atom. Additionally, elastic energy, induced by the substitute atom and accumulated in the lattices, is also derived. Finally, readers can substitute numerical values of parameters of real multi-phase materials into the presented formulae. [ABSTRACT FROM AUTHOR]

Kelvin's 1887 speculation on an ideal foam structure, which was intended to serve as a model for the ether, was a highly imaginative conception, brilliantly carried through into detailed calculations. It eventually launched the Kelvin Problem, which asks how space may be partitioned into cells of fixed equal volume with minimum surface area. Although it could be said to be misguided in motivation, faulty in logic and even mistaken in its conclusions, the paper nevertheless stands as an enduring classic and Kelvin's foam remains of great interest today. [ABSTRACT FROM AUTHOR]

Background: Glioma is a main cause of brain-cancer relevant death. The present paper designed to reveal the possible role of LSINCT5 in human glioma GL15 cells. Methods: LSINCT5 and miR-451 expression in glioma tissues was examined using qRT-PCR. The impacts of LSINCT5, miR-451 and Rac1 in GL15 cells were checked by carrying out CCK-8 assay, transwell assay, and flow cytometric analysis. Further, the target gene of LSINCT5 and miR-451 was explored. Accumulation of PI3K/AKT, Wnt/β-catenin and NF-κB pathway proteins was examined using Western blot. Results: LSINCT5 was highly expressed while miR-451 low expressed in glioma tissues when compared to normal controls. Down-regulating LSINCT5 effectively declined GL15 cells viability, migration and invasion, but accelerated apoptosis. Nonetheless, the above-mentioned effects of LSINCT5 down-regulation were weakened when miR-451 was silenced. Rac1 was a target of miR-451. The tumour-suppressive effects of miR-451 on GL15 cells were weakened when Rac1 was overexpressed. Further, LSINCT5-miR-451-Rac1 axis could impact the activation of PI3K/AKT, Wnt/β-catenin and NF-κB pathways. Conclusion: Down-regulation of LSINCT5 represses glioma cells growth and metastasis in vitro likely through targeting miR-451 and thereby inhibiting Rac1-regulated PI3K/AKT, Wnt/β-catenin and NF-κB pathways. [ABSTRACT FROM AUTHOR]

Thyroid carcinoma is the most widespread malignancy in endocrine system with the increasing incidence. Despite of the advanced approaches to the management of thyroid carcinoma, the therapeutic effects remain unpleasant largely due to the radiosensitivity of thyroid carcinoma cells. LncRNAs play important part in the tumorigenesis and development, especially in the radiosensitivity of tumor cells. However, their roles in thyroid carcinoma still needed to be explored deeply. The purpose of our research is to inspect the possible biological role and regulation mechanism of LINC00511 desirable for therapies of thyroid carcinoma patients. In the present study, LINC00511 was significantly overexpressed in thyroid carcinoma and its silencing boosted radiosensitivity of thyroid carcinoma cells. Then we unveiled that LINC00511 regulated JAK2/STAT3 signaling pathway which was resistant to radiation treatment. Besides, TAF1 modulated JAK2 at transcriptional level. Moreover, LINC00511 bound to TAF1 and further promoted JAK2 expression. In conclusion, rescue experiments verified that the radiosensitivity of thyroid carcinoma cells was attributed to LINC00511/TAF1/JAK2/STAT3 axis. The current paper investigated the underlying mechanism of LINC00511 and set a new therapeutic direction for the therapy of thyroid carcinoma. [ABSTRACT FROM AUTHOR]

In this paper we outline an interdisciplinary collaborative approach to problem solving that can be characterised as performative as both the goals and solutions develop over time through an open-ended process of trial-and-error. We describe two projects where this methodology has been successfully applied. We first give an overview of the CELL project where the performative approach led to a significant change in the way that scientist Neil Theise investigated stem cells. The success of this project directly led to the work which is the main focus of this paper: the design of Net Work, an interactive artwork that consists of a grid of autonomous buoys that emit different coloured light in response to the environment and the state of neighbouring buoys. We describe our performative approach to building the Net Work prototype and outline in detail its control system which is based on Ashby's homeostat model. The paper concludes with a short discussion of some of the benefits and pitfalls of an interdisciplinary collaborative approach to problem solving. [ABSTRACT FROM AUTHOR]

This paper considers the joint cell clustering-layout problem where machine cells are to be located along the popular bidirectional linear material flow layout. The joint problem seeks to minimize the actual intercell flow cost instead of the typical measure that minimizes the number of intercell movements when the layout problem is excluded from the clustering process. Owing to the computational difficulty, a three-phase approach is proposed using the cut-tree-network model to solve this joint problem. The cell clustering and layout problem is transformed into a multi-terminal network flow model. A cut tree is constructed and partitioned into a number of subgraphs via the selected primary path. Each subgraph is a clustered cell and their locations are assigned to the layout sequence by comparing the cut capacities. Thus, the proposed approach concurrently determines the machine cells and their relative sequences in the bidirectional linear flow layout. Computational procedures are illustrated and additional experiments, with data adapted from the literature, are performed to demonstrate the viability of the approach. [ABSTRACT FROM AUTHOR]

Industry 4.0 stresses the importance of considering production automation as an integrated and collaborative teamwork process between human workers and intelligent machines and tools. Collaborative robotics is a recent field of study for industrial automation. Although fenceless robot systems are available, the actual implementation of collaborative schemes for the conduction of assembly jobs should be supported through dedicated procedures and guidelines. These procedures have yet to be found and defined in detail. In this work, the authors claim that it may be possible to approach the problem of collaborative cell design with the methods devised for lean thinking. In the paper, the most common lean strategies are listed and analysed from the viewpoint of setting up a collaborative work cell. The most suitable strategies and tools are then recommended in a methodology that has been proposed to redesign an industrial assembly cell. The methodology has then been adopted in the presented industrial use case which is focused on the steps of HRC design process such as tasks assignment and scheduling. [ABSTRACT FROM AUTHOR]

A 3-indolylacrylate derivative, 3-IA, prepared by connecting an ethyl acrylate in 3-position of indole has been synthesised and characterised. Ethyl acrylate moiety acts as the Michael acceptor towards H2S, and the resultant addition product then participates in intramolecular cyclisation with the ester group at 2-position to form another new heterocyclic ring. Blue fluorescence of 3-IA turned into green in presence of H2S, leading to ratiometric behaviour of the fluorescent sensor with large stokes shift of 55 nm. Probe 3-IA has excellent selectivity towards H2S over other biothiols and other competing anions. Density function theory/time-dependent density function theory calculations were carried out to validate the reaction mechanism and the electronic properties of 3-IA. Importantly, the ratiometric probe 3-IA shows great promise in H2S detection by simple visual fluorescent inspection in filter paper-based protocol. The probe shows its excellent ability to detect H2S in different natural water samples. Furthermore, we have employed our probe to detect H2S for ratiometric imaging in live Vero cell. [ABSTRACT FROM AUTHOR]

In this paper, the problem of fault detection and isolation in a three-cell converter is investigated using a nonlinear geometric approach. This powerful method based on the unobservability distribution is used to detect and isolate the faulty cell in the three-cell converter. First, a model describing the faults in the cells is presented. The geometric approach is then applied on this faulty model to generate residual signals based on a sliding-mode observer that allows the detection of faults in the three-cell converter. Numerical results show the effectiveness of the proposed sliding-mode residual generators for fault detection and isolation in the three-cell converter. [ABSTRACT FROM AUTHOR]

An introduction to the journal is presented in which the guest editors present papers, from the Symposium on Fluorochromes of Biological Stain Commission held in Rochester, New York in June 2012, that details different methods of imaging live cell utilizing fluorescence.

Three recent papers, published just weeks apart, describe the use of fluorescent TALEs to tag specific DNA sequences in live cells and, in one case, also in fixed cells, the latter with potential clinical applications. [ABSTRACT FROM AUTHOR]

Purpose: In 2011, the International Commission on Radiological Protection reduced the threshold for the lens effects of low linear energy transfer (LET) radiation. On one hand, the revised threshold of 0.5 Gy is much lower than previously recommended thresholds, but mechanisms behind high radiosensitivity remain incompletely understood. On the other hand, such a threshold is independent of dose rate, in contrast to previously recommended separate thresholds each for single and fractionated/protracted exposures. Such a change was made predicated on epidemiological evidence suggesting that a threshold for fractionated/protracted exposures is not higher than an acute threshold, and that a chronic threshold is uncertain. Thus, the dose rate dependence is still unclear. This paper therefore reviews the current knowledge on the radiosensitivity of the lens and the dose rate dependence of radiation cataractogenesis, and discusses its mechanisms. Conclusions: Mounting biological evidence indicates that the lens cells are not necessarily radiosensitive to cell killing, and the high radiosensitivity of the lens thus appears to be attributable to other mechanisms (e.g., excessive proliferation, abnormal differentiation, a slow repair of DNA double-strand breaks, telomere, senescence, crystallin changes, non-targeted effects and inflammation). Both biological and epidemiological evidence generally supports the lack of dose rate effects. However, there is also biological evidence for the tissue sparing dose rate (or fractionation) effect of low-LET radiation and an enhancing inverse dose fractionation effect of high-LET radiation at a limited range of LET. Emerging epidemiological evidence in chronically exposed individuals implies the inverse dose rate effect. Further biological and epidemiological studies are warranted to gain deeper knowledge on the radiosensitivity of the lens and dose rate dependence of radiation cataractogenesis. [ABSTRACT FROM AUTHOR]

A pronounced dominance of toxic cyanobacteria has been found in eutrophic water bodies, with Microcystis being a common species. Although toxic cyanobacteria are commonly described worldwide, few recent papers on the sensitive and effective quantification of cyanobacteria have been published. In this paper, a multi-technique approach was applied by the use of cell density counting, cell viability testing, chlorophyll a determination, microcystin monitoring and gene extraction techniques to quantitatively analyse the cyanobacterial biomass of Microcystis aeruginosa FACHB-905. The entire dataset was used to examine the relationships between these indices. Results showed that, for 107 viable cells in the experimental conditions, the contents of chlorophyll a, microcystin-LR and total genes (16S rDNA) averaged 2.65 μg, 0.61 μg and 0.79 μg, respectively. For different cell viability proportions in the same particular phase of growth, it is easy to obtain the respective amount of viable cells and inactive cells and their measurable indices when any one of the three indices, chlorophyll a, DNA or microcystin-LR, is measured. This study provides a new perspective and method for determining multiple indices of toxic cyanobacteria during the same conditions and phases. [ABSTRACT FROM PUBLISHER]

This paper introduces the Basic Ordnance Observation Management System, a prototype application supporting geovisual exploration and analysis of improvised explosive device (IED) incidents. Use of IEDs by terrorist cells has increased in geographic scale, frequency, and sophistication due to the relative cheap cost of acquiring the materials and the ease in keeping such weaponry covert. The Basic Ordnance Observational Management System is designed to facilitate spatiotemporal sensemaking of the IED incident dataset maintained by the National Counter Terrorism Center, Worldwide Incident Tracking System. The application expands upon existing geovisual analytics tools for understanding patterns, trends, and anomalies in IED activity through provision of a suite of capabilities that include: flexible spatial and temporal aggregates of the IED dataset; linked spatial, temporal, and attribute views of the incident information; temporal re-expression, particularly the generation of linear and composite sequences of the IED dataset; and temporal animation across IED activity, with 'VCR' controls and an interactive temporal legend to control the animation as well as visual benchmarks to assist with interpretation of the animation. [ABSTRACT FROM AUTHOR]

Functional nanomaterials have recently attracted strong interest from the biology community, not only as potential drug delivery vehicles or diagnostic tools, but also as optical nanomaterials. This is illustrated by the explosion of publications in the field with more than 2,000 publications in the last 2 years (4,000 papers since 2000; from ISI Web of Knowledge, 'nanoparticle and cell' hit). Such a publication boom in this novel interdisciplinary field has resulted in papers of unequal standard, partly because it is challenging to assemble the required expertise in chemistry, physics, and biology in a single team. As an extreme example, several papers published in physical chemistry journals claim intracellular delivery of nanoparticles, but show pictures of cells that are, to the expert biologist, evidently dead (and therefore permeable). To attain proper cellular applications using nanomaterials, it is critical not only to achieve efficient delivery in healthy cells, but also to control the intracellular availability and the fate of the nanomaterial. This is still an open challenge that will only be met by innovative delivery methods combined with rigorous and quantitative characterization of the uptake and the fate of the nanoparticles. This review mainly focuses on gold nanoparticles and discusses the various approaches to nanoparticle delivery, including surface chemical modifications and several methods used to facilitate cellular uptake and endosomal escape. We will also review the main detection methods and how their optimum use can inform about intracellular localization, efficiency of delivery, and integrity of the surface capping. [ABSTRACT FROM AUTHOR]

G-protein coupled receptors (GPCRs) form a ternary complex of agonist, receptor and G-proteins during primary signal transduction at the cell membrane. Downstream signalling is thought to be preceded by the process of dissociation of Gα and Gβγ subunits, thus exposing new surfaces to interact with downstream effectors. We demonstrate here for the first time, the dissociation of heterotrimeric G-protein subunits (i.e., Gα and Gβγ) following agonist-induced GPCR (α 2A -adrenergic receptor; α 2A -AR) activation in a cell-free assay system. α 2A -AR membranes were reconstituted with the G-proteins ( ± hexahistidine-tagged) Gα i1 and Gβ 1 γ 2 and functional signalling was determined following activation of the reconstituted receptor:G-protein complex with the potent agonist UK-14304, and [ 35 S]GTPγS. In the presence of Ni 2 + -coated agarose beads, the activated his-tagged Gα i1 his-[ 35 S]GTPγS complex was captured on the Ni 2 + -presenting surface. When his-tagged Gβ 1 γ 2 (Gβ 1 γ 2 his) was used with Gα i1 , the [ 35 S]GTPγS-bound Gα i1 was not present on the Ni 2 + -coated beads, but rather, it was separated from the β 1 γ 2 (his)-beads, demonstrating receptor-induced dissociation of Gα and Gβγ subunits. Treatment of the reconstituted α 2A -AR membranes containing Gβ 1 γ 2 his:Gα i1 with imidazole confirmed the specificity for the Ni 2 + :G-protein surface dissociation of Gα i1 from Gβ 1 γ 2 his. These data demonstrate for the first time, the complete dissociation of the G-protein subunits and extend observations on the role of G-proteins in the assembly and disassembly of the ternary complex in the primary events of GPCR signalling. [ABSTRACT FROM AUTHOR]

A cells viability can be altered by the presence of bioactive materials particles and their features. This paper compares the influence of hydroxyapatite particles and bioactive glass particles on intracellular ionic concentrations of the monocytes exposed to them. However, microanalysis of intracellular ions like sodium, potassium, and chlorine is a major problem. In order to limit diffusion phenomenon and to preserve the chemical identity of specimens, we used cryomethods (cryo-preparation, and cryo-x- ray microanalysis) to study cells in contact with bioactive materials particles. We measured intracellular ionic concentrations by scanning transmission electron microscopy (STEM) associated with energy dispersive x-ray spectroscopy (EDXS). Monocytes were exposed to bioactive glass particles and to hydroxyapatite particles during 2 days. The K/Na ratio was used as a sensitive criteria of viability of cells. [ABSTRACT FROM AUTHOR]

Microtubules (MTs) are protein filaments that provide structure to the cytoskeleton of cells and a platform for the movement of intracellular substances. The spatial organization of MTs is crucial for a cell's form and function. MTs interact with a class of proteins called motor proteins that can transport and position individual filaments, thus contributing to overall organization. In this paper, we study the mathematical properties of a coupled partial differential equation (PDE) model, introduced by Whiteet al.in 2015, that describes the motor-induced organization of MTs. The model consists of a nonlinear coupling of a hyperbolic PDE for bound motor proteins, a parabolic PDE for unbound motor proteins, and a transport equation for MT dynamics. We locally smooth the motor drift velocity in the equation for bound motor proteins. The mollification is not only critical for the analysis of the model, but also adds biological realism. We then use a Banach Fixed Point argument to show local existence and uniqueness of mild solutions. We highlight the applicability of the model by showing numerical simulations that are consistent within vitroexperiments. [ABSTRACT FROM PUBLISHER]

Probiotic bacteria are being increasingly added to food for developing products with health-promoting properties. However, the efficacy of probiotics in commercial products is often questioned due to the loss of their viability during shelf storage and in human gastrointestinal tracts. Encapsulation of probiotics has been expected to provide protection to probiotics, but not many commercial products contain encapsulated and viable probiotic cells owing to various reasons. To promote the development and application of encapsulation technologies, this paper has critically reviewed previous publications with a focus on the areas where studies have fallen short, including insufficient consideration of structural effects of encapsulating material, general defects in encapsulating methods and issues in evaluation methodologies and risk assessments for application. Corresponding key issues that require further studies are highlighted. Some emerging trends in the field, such as current treads in encapsulating material and recently advanced encapsulation techniques, have also been discussed. [ABSTRACT FROM AUTHOR]

Dynamic mechanical behaviour of living cells has been described by viscoelasticity. However, quantitation of the viscoelastic parameters for living cells is far from sophisticated. In this paper, combining inverse finite element (FE) simulation with Atomic Force Microscope characterization, we attempt to develop a new method to evaluate and acquire trustworthy viscoelastic index of living cells. First, influence of the experiment parameters on stress relaxation process is assessed using FE simulation. As suggested by the simulations, cell height has negligible impact on shape of the force–time curve, i.e. the characteristic relaxation time; and the effect originates from substrate can be totally eliminated when stiff substrate (Young’s modulus larger than 3 GPa) is used. Then, so as to develop an effective optimization strategy for the inverse FE simulation, the parameters sensitivity evaluation is performed for Young’s modulus, Poisson’s ratio, and characteristic relaxation time. With the experiment data obtained through typical stress relaxation measurement, viscoelastic parameters are extracted through the inverse FE simulation by comparing the simulation results and experimental measurements. Finally, reliability of the acquired mechanical parameters is verified with different load experiments performed on the same cell. [ABSTRACT FROM AUTHOR]

Resonance-based contact-impedance measurement refers to the application of resonance sensors based on the measurement of the changes in the resonance curve of an ultrasonic resonator in contact with a surface. The advantage of the resonance sensor is that it is very sensitive to small changes in the contact impedance. A sensitive micro tactile sensor (MTS) was developed, which measured the elasticity of soft living tissues at the single-cell level. In the present paper, we studied the method of improving the touch and stiffness sensitivity of the MTS. First, the dependence of touch sensitivity in relation to the resonator length was studied by calculating the sensitivity coefficient at each length ranging from 9 to 40 mm. The highest touch sensitivity was obtained with a 30-mm-long glass needle driven at a resonance frequency of 100 kHz. Next, the numerical calculation of contact impedance showed that the highest stiffness sensitivity was achieved when the driving frequency was 100 kHz and the contact-tip diameter of the MTS was 10 μm. The theoretical model was then confirmed experimentally using a phase-locked-loop-based digital feedback oscillation circuit. It was found that the developed MTS, whose resonant frequency was 97.030 kHz, performed with the highest sensitivity of 53.2 × 106 Hz/N at the driving frequency of 97.986 kHz, i.e. the highest sensitivity was achieved at 956 Hz above the resonant frequency. [ABSTRACT FROM PUBLISHER]

Long noncoding RNAs (lncRNAs) are a large class of non (protein)-coding RNAs, which are longer beyond 200 nucleotides. LncRNA GAS5 is widely considered as a tumour suppressor in cell proliferation, apoptosis, cell migration and invasion of tumour cells. Recently, a growing body of evidences indicated that GAS5 was also widely involved in the pathologic process of cardiovascular cells, including regulation of apoptosis and inflammatory injury of cardiomyocytes; proliferation, apoptosis, autophagy and angiogenesis of endothelial cells; and proliferation, migration, apoptosis and differentiation of VSMCs. In this regard, we summarised current studies of GAS5 in cardiovascular cells, which shed light on not only our understanding of the mechanisms of GAS5 in cardiovascular cells but also understanding of the potential of GAS5 as novel therapeutic target. [ABSTRACT FROM AUTHOR]

Synthetic biology is an emerging research field, in which engineering principles are applied to natural, living systems. A major goal of synthetic biology is to harness the inherent “biological nanotechnology” of living cells for the purposes of computation, production or diagnosis. As the field evolves, it is gradually developing from a single-cell approach (akin to using standalone computers) to a distributed,population-basedapproach (akin to usingnetworksof connected machines). We anticipate this eventually representing the “third wave” of synthetic biology (the first two waves being the emergence ofmodulesandsystems, respectively, with the second wave still yet to peak). In this paper, we review the developments that are leading to this third wave, and describe some of the existing scientific and technological challenges. [ABSTRACT FROM AUTHOR]

Diagrams feature prominently in science education, and there has been an increase in research focusing on students’ use of them in knowledge construction. This paper reports on an investigation into first year university students’ perceptions of scale and size at the cellular level. It was found that many students appeared to tacitly assume that textbook diagrams presented cellular components in true relative size, leading to widespread interpretative problems with regard to scale and absolute size. The paper includes recommendations for textbook designers and classroom practitioners. [ABSTRACT FROM PUBLISHER]

Mathematical models of cardiac electro-mechanics typically consist of three tightly coupled parts: systems of ordinary differential equations describing electro-chemical reactions and cross-bridge dynamics in the muscle cells, a system of partial differential equations modelling the propagation of the electrical activation through the tissue and a nonlinear elasticity problem describing the mechanical deformations of the heart muscle. The complexity of the mathematical model motivates numerical methods based on operator splitting, but simple explicit splitting schemes have been shown to give severe stability problems for realistic models of cardiac electro-mechanical coupling. The stability may be improved by adopting semi-implicit schemes, but these give rise to challenges in updating and linearising the active tension. In this paper we present an operator splitting framework for strongly coupled electro-mechanical simulations and discuss alternative strategies for updating and linearising the active stress component. Numerical experiments demonstrate considerable performance increases from an update method based on a generalised Rush–Larsen scheme and a consistent linearisation of active stress based on the first elasticity tensor. [ABSTRACT FROM AUTHOR]

The intestine of Caenorhabditis elegans is derived from 20 cells that are organized into nine intestinal rings. During embryogenesis, three of the rings rotate approximately 90 degrees in a process known as intestinal twist. The underlying mechanisms for this morphological event are not fully known, but it has been demonstrated that both left-right and anterior-posterior asymmetry is required for intestinal twist to occur. We have recently presented a rule-based meta- Boolean tree model intended to describe complex lineages. In this report we apply this model to the E lineage of C. elegans, specifically targeting the asymmetric anterior-posterior division patterns within the lineage. The resulting model indicates that cells with the same factor concentration are located next to each other in the intestine regardless of lineage origin. In addition, the shift in factor concentrations coincides with the boundary for intestinal twist. When modeling lit-1 mutant data according to the same principle, the factor distributions in each cell are altered, yet the concurrence between the shift in concentration and intestinal twist remains. This pattern suggests that intestinal twist is controlled by a threshold mechanism. In the current paper we present the factor concentrations for all possible combinations of symmetric and asymmetric divisions in the E lineage and relate these to the potential threshold by studying existing data for wild-type and mutant embryos. Finally, we discuss how the resulting models can serve as a basis for experimental design in order to reveal the underlying mechanisms of intestinal twist. [ABSTRACT FROM AUTHOR]

In this paper, two methods are developed for statistically analysing the nonlinear cellular dynamics from numerical simulations of gaseous detonations, one use of which is the systematic determination of detonation cell sizes from such simulations. Both these methods rely on signed vorticity records in which the individual families of transverse waves are captured independently. The first method involves an automated extraction of the main triple-point tracks from the vorticity records, allowing statistical analysis of the spacings between neighbouring tracks. The second method uses the autocorrelation function to spectrally analyse the vorticity records. These methods are then employed for a preliminary analysis of the cellular dynamics of the standard, idealized one-step chemistry model. Evidence is found for 'cell size doubling' bifurcations in the one-step model as the cellular dynamics become more irregular (e.g. as the activation is increased). It is also shown that the statistical models converge slowly due to systematic 'shot-to-shot' variation in the cellular dynamics for fixed parameters with different initial perturbations. Instead, it appears that a range of equally probable cell sizes can be obtained for given parameters. [ABSTRACT FROM AUTHOR]

Derivative spectrophotometry is an analytical technique of great utility for extracting both qualitative and quantitative information from spectra composed of unresolved bands by calculating and plotting one of the mathematical derivatives of a spectral curve. In photodynamic therapy (PDT) by irradiation with light, the porphyrin used as drugs induced DNA cleavage mainly via a Type II (singlet oxygen mediated) mechanism, and more rarely a Type I (radicals mediated) mechanism. In the present paper, it is estimated the distinct interactions between DNA and 5,10,15,20-tetra-sulphonated-phenyl-porphyrin (TSPP) by means of: UV-Vis derivative spectrophotometry coupled with melting point, fluorescence, and polarization fluorescence techniques. An exemplification of TSPP effect on DNA from K562 cells is also discussed. [ABSTRACT FROM AUTHOR]

Although neurons within the peripheral nervous system have a remarkable ability to repair themselves after injury, neurons within the central nervous system do not spontaneously regenerate. This problem has remained recalcitrant despite a century of research on the reaction of axons to injury. The balance between inhibitory cues present in the environment and the intrinsic growth capacity of the injured neuron determines the extent of axonal regeneration following injury. The cell body of an injured neuron must receive accurate and timely information about the site and extent of axonal damage in order to increase its intrinsic growth capacity and regenerate successfully. One of the mechanisms contributing to this process is retrograde transport of injury signals. For example, molecules activated at the injury site convey information to the cell body leading to the expression of regeneration-associated genes and increased growth capacity of the neuron. In this paper, we are introducing therapeutic agents to treat brain injury and peripheral nerve injury. Since glial cell adhesion molecule is upregulated in gliotic scar, it is possible to target therapeutic agents to the site of brain injury. This directed therapy presents an innovative and promising therapy. [ABSTRACT FROM AUTHOR]

Abstract: The nervous system of seeing animals derives information about optic flow in two subsequent steps. First, local motion vectors are calculated from moving retinal images, and second, the spatial distribution of these vectors is analyzed on the dendrites of large downstream neurons. In dipteran flies, this second step relies on a set of motion-sensitive lobula plate tangential cells (LPTCs), which have been studied in great detail in large fly species. Yet, studies on neurons that convey information to LPTCs and neuroanatomical investigations that enable a mechanistic understanding of the underlying dendritic computations in LPTCs are rare. We investigated the subcellular distribution of nicotinic acetylcholine receptors (nAChRs) on two sets of LPTCs: vertical system (VS) and horizontal system (HS) cells in Drosophila melanogaster. In this paper, we describe that both cell types express Dα7-type nAChR subunits specifically on higher order dendritic branches, similar to the expression of gamma aminobutyric acid (GABA) receptors. These findings support a model in which directional selectivity of LPTCs is achieved by the dendritic integration of excitatory, cholinergic, and inhibitory GABA-ergic input from local motion detectors with opposite preferred direction. Nonetheless, whole-cell recordings in mutant flies without Dα7 nAChRs revealed that direction selectivity of VS and HS cells is largely retained. In addition, mutant LPTCs were responsive to acetylcholine and remaining nAChR receptors were labeled by α-bungarotoxin. These results in LPTCs with genetically manipulated excitatory input synapses suggest a robust cellular implementation of dendritic processing that warrants direction selectivity. The underlying mechanism that ensures appropriate nAChR-mediated synaptic currents and the functional implications of separate sets or heteromultimeric nAChRs can now be addressed in this system. [ABSTRACT FROM AUTHOR]

The combination of parallel machines and multiple dual gripper robots has become increasingly prevalent in modern manufacturing with robotic cells. However, there has been no previous study of the design and scheduling challenges faced by managers who employ these complex cells. The benefit of implementing dual grippers in cells with multiple robots over cells with the same number of single gripper robots is quantified in this paper. Configuration decisions are addressed by comparing different implementations of multi-robot cells to show that the method of exchanging parts between robots (shared machines versus transfer stations) has little bearing on the throughput. In contrast, it is demonstrated that the assignment of processing stages to robots can have a significant effect on a cell's potential throughput. A scheme that allows multiple robots to cooperate without colliding or suffering gridlock is described; this is realized with minimal impact on throughput. The optimality is analytically established, under conditions that are very common in practice, for a particular cyclic sequence of robot moves in robotic cells with one or more dual gripper robots, parallel machines and transfer stations. [ABSTRACT FROM AUTHOR]

This paper describes the morphology and fine structure of adhesive organ (AO) of the snow trout Schizothorax richardsonii (Gray, 1832). The species lives in the sub-Himalayan streams and rivers, where they adhere to submerged rocks and stones with its AO located beneath the mouth opening. The AO consists of a crescent callus part and a modified labial fold, bearing numerous tubercles. In both parts, the epidermis is exceptionally thick (150-170 µm) and contains keratinocytes rich in bundles of tonofilaments; elsewhere, the epidermis contains single, disperse filaments, mucous cells and other usual cells seen in teleosts. Unlike epidermis elsewhere, the outer 4-5 row cells of the AO epidermis undergo keratinisation and are cytokeratin positive. The individual keratinised cell layers, which are degenerated electron-dense sheets, lack nuclei and cytoplasmic organelles, but possess filaments embedded in a dense cytoplasmic matrix and few, large mucous-like granules. Beneath the keratinised layers, keratinocytes are compactly aligned into 20-25 rows. They possess abundant thick bundles of clumped tonofilaments over the entire cytoplasm and peripherally, small mucous granules. Towards the basal epidermis, the cells are elongated and show major cytoplasmic organelles, few tonofilament bundles, but no mucous granules. It is evident that the keratinocytes of the mid-epidermis are differentiated for the production of tonofilaments. The outer keratinised part of the AO epidermis provides structural support and protection (from damage) during adhesion. It appears that the callus part acts by creating vacuum first, while the tuberculated part of the AO epidermis assists in adhesion to the rocky substratum. [ABSTRACT FROM AUTHOR]

Systemic infections are often associated with neurodegenerative processes in many diseases of the central nervous system (CNS), including Parkinson's disease. Toll-like receptor (TLR)4 and CD14 act as receptors for lipopolysaccharide (LPS) released by gram-negative bacteria. In this contest, CD14 functions as the main LPS ligand and TLR4 transmits the LPS signal into the cell. In this paper, we investigated the expression of TLR4 and CD14, in different anatomical areas of the CNS, in an experimental model of Parkinson's-like disease, represented by MPTP-treated mouse. In particular, we analyzed the gene transcripts and proteins expression of CD14 and TLR4, in the substantia nigra and caudate-putamen nuclei of these animals. Results demonstrated an augmented expression of both CD14 and TLR4 in the substantia nigra of mice treated with MPTP in comparison to untreated animals, suggesting that the endotoxin receptors are over expressed in different manner in specific areas of the CNS during Parkinson's-like disease. [ABSTRACT FROM AUTHOR]

Staining morphological or chemical constituents of biological tissues, cells and microorganisms with silver proceeds via different reaction routes. In this paper, I put their physicochemical mechanisms into a coherent system and discuss how these can be controlled and separated from each other, thereby permitting selective, sensitive and reliable demonstration of individual tissue constituents. [ABSTRACT FROM AUTHOR]

Cylindrospermopsis raciborskii, a problem-causing cyanobacterium capable of releasing potent toxins, has become increasingly prevalent in South African freshwaters, especially in the lower reaches of the Orange River. This organism was first detected during the summer (January to March) of 2000 in the lower reaches of the Orange River. During this period, and again in 2003 and 2005, it formed severe summer blooms, occasionally reaching concentrations of 1 000 000 cells ml-1. Blooms of C. raciborskii lead to several problems including taste and odours, as well as making water treatment difficult (conventional treatment processes were unsuccessful). Fish kills were also reported during the time of the bloom. According to the World Health Organisation, cyanobacterial concentrations greater than or equal to 100 000 cells ml-1 may be detrimental to human health. It seems as if this organism is slowly spreading into other freshwater systems in the country. While it was restricted mainly to the lower Orange River system during 2000, it has since been found in low concentrations in a large number of rivers throughout South Africa. The spread of this organism should be monitored, because it may have devastating consequences for the precious and scarce water resources in the country. The primary aim of this paper is to act as a report on the presence of C. raciborskii in the lower Orange River and as a warning of its potential to form blooms in other South African freshwaters. A short overview of its distribution of this species in South Africa is provided, as well as a brief summary of environmental conditions during the 2005 bloom period. Management recommendations are also listed. [ABSTRACT FROM AUTHOR]

In the present paper we report the results of our study aimed to the morphological and cytochemical identification of dissociated Petrosia ficiformis cells, a sponge species common on the rocky shores of the Mediterranean Sea. Indeed, in most species classification of sponge cells is difficult for their high plasticity and totipotency, beside the absence of organs and tissues. In a 30-year-old classification, four main classes of sponge cells were identified: covering cells, scleroblast-like cells, i.e. cells secreting the skeleton, contractile cells and archeocytes. After mechanical dissociation of the specimens collected in the Adriatic Sea, we identified three main cell types, with a diameter ranging from 2 µm to 20 µm: (i) choanocytes, very small cells (5 µm in diameter), (ii) archeocytes, intermediate size cells (from 5 to 10 µm in diameter), (iii) spherulous cells, very heterogeneous elements (8-20 µm in diameter). Indeed, the cytoplasm of these latter cells is filled by a variable number of granules, which confer peculiar cytochemical staining patterns. In addition, we also identified the relevant presence of symbiotic microorganisms, namely cyanobateria, preferentially distributed inside the ectosome. [ABSTRACT FROM AUTHOR]

The nonsynchronous coil planet centrifuge has a unique mode of planetary motion in that it allows a freely adjustable rotational rate of the coiled separation column at a given revolution speed. This paper describes a series of studies using the apparatus fabricated in our laboratory on the countercurrent chromatographic separation of proteins with aqueous-aqueous polymer phase systems, experimental and theoretical analysis of the effect of planetary motion on protein separation, and application to elutriation of cells such as blood cell components and mast cells using a single-phase physiological buffer solution. [ABSTRACT FROM AUTHOR]

Dual frequency addressing of nematic pi-cell devices produces submillisecond switching times since the liquid crystal can be driven both parallel and perpendicular to the applied field and there is no kick-back of the director during switching. The nucleation of the V state in devices containing dual frequency liquid crystal materials is much slower than that in conventional pi-cells, however. Polymer stabilization of the V state eliminates the need for nucleation each time the device is used. In this paper we present a polymer stabilized pi-cell containing a dual frequency liquid crystal material, and show that the presence of the polymer network significantly influences the switching of the device. Some optimization of the addressing scheme is required when switching the polymer stabilized device in order to avoid transient formation of the twisted state. Using this optimization, the switching time is under 3 ms across a wide range of addressing voltages. [ABSTRACT FROM AUTHOR]