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Microbial fuel cells (MFCs) are receiving considerable attention for generating clean and sustainable electrical energy directly from wastewater. The development of highly efficient, durable, and i...

Fiber optic sensors (FOSs) based on the lossy mode resonance (LMR) technique have gained substantial attention from the scientific community. The LMR technique displays several important features over the conventional surface plasmon resonance (SPR) phenomenon, for planning extremely sensitive FOSs. Unlike SPR, which mainly utilizes the thin film of metals, a wide range of materials such as conducting metal oxides and polymers support LMR. The past several years have witnessed a remarkable development in the field of LMR-based fiber optic sensors; through this review, we have tried to summarize the overall development of LMR-based fiber optic sensors. This review article not only provides the fundamental understanding and detailed explanation of LMR generation but also sheds light on the setup/configuration required to excite the lossy modes. Several geometries explored in the literature so far have also been addressed. In addition, this review includes a survey of the different materials capable of supporting lossy modes and explores new possible LMR supporting materials and their potential applications in sensing.

Use of natural fibers in polymer composites is the modern trend towards development of materials possessing several benefits such as low cost, environment friendly, biodegradable and high specific mechanical performance. Natural fiber polymer composites are used in various applications like automobile interior body, beams and panels, aircraft interiors as flooring, ceilings, galley walls, lavatories and cargo-hold liners etc. In this work the composites were prepared by two roll mixing mill followed by compression moulding. The effect of fiber loading (10, 20, 30 Wt.%) on tensile and flexural properties were tested for with and without alkali treated test samples. The 10 wt.% of kenaf fiber shows maximum tensile properties and flexural properties were found maximum for the composite with 30 wt.% of kenaf fiber. Further, detailed DMA (Dynamic mechanical analysis) were carried out in order to observe the reinforcing behavior of kenaf fibers. The value of damping (Tan δ) shows better fiber/matrix interface bonding for treated kenaf fiber composite due to alkali treatment. In future this material can be used for potential secondary load bearing structures in the automotive sector.

A statically non-wetting, electrospun surface of non volatile room temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium hexafluorophosphate, (BMIM-PF 6 ), hosted in a solution-processable, semi-fluorinated perfluorocyclobutyl (BP-PFCB) aryl ether polymer was successfully prepared by electrospinning and compared with a surface prepared by spin casting. The surface properties of undoped and BMIM-PF 6 doped systems were analyzed by water contact angle (WCA) and atomic force microscopy (AFM). BMIM-PF 6 doped BP-PFCB surfaces prepared by spin casting showed a WCA of 90° while non-woven electrospun surfaces with the same BMIM-PF 6 concentration showed high degree of hydrophobicity with a WCA greater than 150°. Morphologies of the electrospun surfaces were characterized by scanning electron microscopy (SEM). The surface composition was analyzed by energy-dispersive X-ray spectroscopy (EDXS) and attenuated total reflectance infrared spectroscopy (ATR-IR). Thermal analysis of the electrospun, non-woven surfaces of the doped and the undoped system of BP-PFCB were done by TGA.

Despite the fact that the processing of nanoceramics composites have been triggered to a great extent, the evaluation of their potential in engineering application is rather limited. To this end, the present work reports the results obtained with fretting wear (mode I, linear tangential displacement sliding) of Y-TZP nanoceramics, optimally densified using spark plasma sintering route. The tribological experiments were conducted by varying normal load (2–10N) for 100,000 fretting cycles with relative displacement stroke of 50 μm at a frequency of 8 Hz. Based on the investigation of the topographical features of worn surfaces, the mechanism of material removal has been proposed. An important finding is that TZP nanoceramic/steel tribocouple exhibit an increase in COF from 0.2 to 0.5 as well as severe wear damage with increase in load from 2N to 5N and above, under the selected experimental conditions.

A quarter of animal species in the world are in fear of extinction. The advent of induced pluripotency has opened alternate avenues to produce embryonic stem-like cells from somatic cells and provide a unique tool to elucidate both pluripotency and lineage assignment. To consider whether this technology could be applied to endangered species, where the limited availability of gametes makes production and research on embryonic stem cells difficult, we have investigated the use of reprogramming transcription factors for use in induction of pluripotency in wild cats.

The molecular and phenotypic irreversibility of mammalian cell differentiation was a fundamental principle of developmental biology at least until the 1980s, despite numerous reports dating back to the 1950s of the induction of pluripotency in amphibian cells by nuclear transfer (NT). Landmark reports in the 1980s and 1990s in sheep progressively challenged this dogmatic assumption; firstly, embryonic development of reconstructed embryos comprising whole (donor) blastomeres fused to enucleated oocytes, and famously, the cloning of Dolly from a terminally differentiated cell. Thus, the intrinsic ability of oocyte-derived factors to reverse the differentiated phenotype was confirmed. The concomitant elucidation of methods for human embryonic stem cell isolation and cultivation presented opportunities for therapeutic cell replacement strategies, particularly through NT of patient nuclei to enucleated oocytes for subsequent isolation of patient-specific (autologous), pluripotent cells from the resulting blastocysts. Associated logistical limitations of working with human oocytes, in addition to ethical and moral objections prompted exploration of alternative approaches to generate autologous stem cells for therapy, utilizing the full repertoire of factors characteristic of pluripotency, primarily through cell fusion and use of pluripotent cell extracts. Stunningly, in 2006, Japanese scientists described somatic cell reprogramming through delivery of four key factors (identified through a deductive approach from 24 candidate genes). Although less efficient than previous approaches, much of current stem cell research adopts this focused approach to cell reprogramming and (autologous) cell therapy. This chapter is a quasi-historical commentary of the various aforementioned approaches for the induction of pluripotency in lineage-committed cells, and introduces transcriptional and epigenetic changes occurring during reprogramming.

Nanog has an important role in pluripotency induction in bovines and snow leopards. To examine whether it was required for wild felids globally, we examined the induction of pluripotency in felids from Asia (Bengal tiger, Panthera tigris), Africa (serval, Leptailurus serval), and the Americas (jaguar, Panthera onca). Dermal fibroblasts were transduced with genes encoding the human transcription factors OCT4, SOX2, KLF4, and cMYC with or without NANOG. Both four- and five-factor induction resulted in colony formation at day 3 in all three species tested; however, we were not able to maintain colonies that were generated without NANOG beyond passage (P) 7. Five-factor induced pluripotent stem cell (iPSC) colonies from wild cats were expanded in vitro on feeder layers and were positive for alkaline phosphatase and protein expression of OCT-4, NANOG, and stage-specific embryonic antigen-4 at P4 and P14. Reverse-transcription polymerase chain reaction confirmed that all five human transgenes were transcribed at P4; however, OCT4, SOX2, and NANOG transgenes were silenced by P14. Endogenous OCT4 and NANOG transcripts were detected at P4 and P14 in all cell lines confirming successful reprogramming. At P14, the iPSCs from all three species remained euploid and differentiated in vivo and in vitro into derivatives of the three germ layers. This study describes an effective method for inducing pluripotency in three endangered wild cats from across the globe and confirms Nanog as an essential factor in the reprogramming event. Efficient production of iPSC from endangered felids creates a unique opportunity for species preservation through gamete production, nuclear transfer, embryo complementation, and future novel technologies.

The molecular and phenotypic irreversibility of mammalian cell differentiation was a fundamental principle of developmental biology at least until the 1980s, despite numerous reports dating back to the 1950s of the induction of pluripotency in amphibian cells by nuclear transfer (NT). Landmark reports in the 1980s and 1990s in sheep progressively challenged this dogmatic assumption; firstly, embryonic development of reconstructed embryos comprising whole (donor) blastomeres fused to enucleated oocytes, and famously, the cloning of Dolly from a terminally differentiated cell. Thus, the intrinsic ability of oocyte-derived factors to reverse the differentiated phenotype was confirmed. The concomitant elucidation of methods for human embryonic stem cell isolation and cultivation presented opportunities for therapeutic cell replacement strategies, particularly through NT of patient nuclei to enucleated oocytes for subsequent isolation of patient-specific (autologous), pluripotent cells from the resulting blastocysts. Associated logistical limitations of working with human oocytes, in addition to ethical and moral objections prompted exploration of alternative approaches to generate autologous stem cells for therapy, utilizing the full repertoire of factors characteristic of pluripotency, primarily through cell fusion and use of pluripotent cell extracts. Stunningly, in 2006, Japanese scientists described somatic cell reprogramming through delivery of four key factors (identified through a deductive approach from 24 candidate genes). Although less efficient than previous approaches, much of current stem cell research adopts this focused approach to cell reprogramming and (autologous) cell therapy. This chapter is a quasi-historical commentary of the various aforementioned approaches for the induction of pluripotency in lineage-committed cells, and introduces transcriptional and epigenetic changes occurring during reprogramming.

Ultra low dielectric constant (k = 1.53) materials with self-cleansing properties were synthesized via incorporation of fluorodecyl-polyhedral oligomeric silsesquioxane (FD-POSS) into recently synthesized perfluorocyclopentenyl (PFCP) aryl ether polymers. Incorporation of fluorine rich, high free volume, and low surface energy POSS into a semifluorinated PFCP polymer matrix at various weight percentages resulted in a dramatic drop in dielectric constant, as well as a significant increase in hydrophobicity and oleophobicity of the system. These ultra-low dielectric self-cleansing materials (θtilt = 38°) were fabricated into electrospun mats from a solvent blend of fluorinated FD-POSS with PFCP polymers.

Induced pluripotency is a new approach to produce embryonic stem-like cells from somatic cells that provides a unique means to understand both pluripotency and lineage assignment. To investigate whether this technology could be applied to endangered species, where the limited availability of gametes makes research on embryonic stem cells difficult, we attempted generation of induced pluripotent stem (iPS) cells from snow leopard (Panthera uncia) fibroblasts by retroviral transfection with Moloney-based retroviral vectors (pMX) encoding either 4 (Oct-4, Sox-2, Klf-4 and cMyc) or 5 (Oct-4, Sox-2, Klf-4, cMyc and Nanog) human transcription factors. Transduction efficiency of the retrovirus was ascertained using pMX-green fluorescent protein transgene expression and averaged 96% from 3 repeated experiments. The reprogramming efficiency of initial colony formation was 0.000308% (37/120 000 cells plated) for 4-factor induction compared with 0.000517% (62/120 000) for 5-factor induction. Transduction with 4 factors resulted in the formation of small colonies of cells, which could not be maintained for more than 4 passages (P4). However, addition of Nanog to the transfection cocktail produced stable iPS cell colonies, which formed as early as Day 3. Colonies of cells were selected at Day 5 and expanded in vitro on mouse embryonic fibroblast feeder cells. The resulting cell line was positive for alkaline phosphatase, Oct-4, Nanog and stage-specific embryonic antigen-4 at P14. Also, RT-PCR confirmed that endogenous Oct-4 and Nanog were expressed by snow leopard iPS cells from P4; although all 5 human transgenes were transcribed at P4, Oct-4, Sox-2 and Nanog transgenes were silenced as early as P14, suggesting that reprogramming of the endogenous pluripotent genes had occurred. When injected into immune-deficient mice, snow leopard iPS cells formed teratomas containing tissues representative of the 3 germ layers. This study describes the first derivation of iPS cells from the endangered snow leopard and is also the first report on induced pluripotency in felid species. Our results demonstrate that addition of Nanog to the reprogramming cocktail was essential for derivation of iPS lines in this felid and that iPS cells provide a unique source of pluripotent cells with utility in conservation for cryopreservation of genetics, as a source of reprogrammed donor cells for nuclear transfer or for directed differentiation to gametes in the future.

Induced pluripotency is a new approach to produce embryonic stem-like cells from somatic cells that provides a unique means to understand both pluripotency and lineage assignment. To investigate whether this technology could be applied to endangered species, where the limited availability of gametes makes production and research on embryonic stem cells difficult, we attempted generation of induced pluripotent stem (iPS) cells from snow leopard (Panthera uncia) fibroblasts by retroviral transfection with Moloney-based retroviral vectors (pMXs) encoding four factors (OCT4, SOX2, KLF4 and cMYC). This resulted in the formation of small colonies of cells, which could not be maintained beyond four passages (P4). However, addition of NANOG, to the transfection cocktail produced stable iPS cell colonies, which formed as early as D3. Colonies of cells were selected at D5 and expanded in vitro. The resulting cell line was positive for alkaline phosphatase (AP), OCT4, NANOG, and Stage-Specific embryonic Antigen-4 (SSEA-4) at P14. RT-PCR also confirmed that endogenous OCT4 and NANOG were expressed by snow leopard iPS cells from P4. All five human transgenes were transcribed at P4, but OCT4, SOX2 and NANOG transgenes were silenced as early as P14; therefore, reprogramming of the endogenous pluripotent genes had occurred. When injected into immune-deficient mice, snow leopard iPS cells formed teratomas containing tissues representative of the three germ layers. In conclusion, this was apparently the first derivation of iPS cells from the endangered snow leopard and the first report on induced pluripotency in felid species. Addition of NANOG to the reprogramming cocktail was essential for derivation of iPS lines in this felid. The iPS cells provided a unique source of pluripotent cells with utility in conservation through cryopreservation of genetics, as a source of reprogrammed donor cells for nuclear transfer or for directed differentiation to gametes in the future.