WorldWideScience

Sample records for stemming materials

  1. Materials as stem cell regulators

    Science.gov (United States)

    Murphy, William L.; McDevitt, Todd C.; Engler, Adam J.

    2014-01-01

    The stem cell/material interface is a complex, dynamic microenvironment in which the cell and the material cooperatively dictate one another's fate: the cell by remodelling its surroundings, and the material through its inherent properties (such as adhesivity, stiffness, nanostructure or degradability). Stem cells in contact with materials are able to sense their properties, integrate cues via signal propagation and ultimately translate parallel signalling information into cell fate decisions. However, discovering the mechanisms by which stem cells respond to inherent material characteristics is challenging because of the highly complex, multicomponent signalling milieu present in the stem cell environment. In this Review, we discuss recent evidence that shows that inherent material properties may be engineered to dictate stem cell fate decisions, and overview a subset of the operative signal transduction mechanisms that have begun to emerge. Further developments in stem cell engineering and mechanotransduction are poised to have substantial implications for stem cell biology and regenerative medicine. PMID:24845994

  2. Pre-Service Science Teachers Views on STEM Materials and STEM Competition in Instructional Technologies and Material Development Course

    Science.gov (United States)

    Cetin, Ali; Balta, Nuri

    2017-01-01

    This qualitative study was designed to introduce STEM (Science, Technology, Engineering, Mathematics) activities to preservice science teachers and identify their views about STEM materials. In this context, a competition was organized with 42 preservice science teachers (13 male- 29 female) who took Instructional Technologies and Material…

  3. Graphene-Based Materials for Stem Cell Applications

    Directory of Open Access Journals (Sweden)

    Tae-Hyung Kim

    2015-12-01

    Full Text Available Although graphene and its derivatives have been proven to be suitable for several biomedical applications such as for cancer therapy and biosensing, the use of graphene for stem cell research is a relatively new area that has only recently started to be investigated. For stem cell applications, graphene has been utilized by itself or in combination with other types of materials such as nanoparticles, nanofibers, and polymer scaffolds to take advantage of the several unique properties of graphene, such as the flexibility in size, shape, hydrophilicity, as well as its excellent biocompatibility. In this review, we will highlight a number of previous studies that have investigated the potential of graphene or its derivatives for stem cell applications, with a particular focus on guiding stem cell differentiation into specific lineages (e.g., osteogenesis, neurogenesis, and oligodendrogenesis, promoting stem cell growth, stem cell delivery/transplantation, and effective monitoring of their differentiation. We hope that this review promotes and accelerates the use of graphene-based materials for regenerative therapies, especially for stem cell-based approaches to cure various incurable diseases/disorders such as neurological diseases (e.g., Alzheimer’s disease and Parkinson’s disease, stroke, spinal cord injuries, bone/cartilage defects, and cardiovascular diseases.

  4. Stem cell homing-based tissue engineering using bioactive materials

    Science.gov (United States)

    Yu, Yinxian; Sun, Binbin; Yi, Chengqing; Mo, Xiumei

    2017-06-01

    Tissue engineering focuses on repairing tissue and restoring tissue functions by employing three elements: scaffolds, cells and biochemical signals. In tissue engineering, bioactive material scaffolds have been used to cure tissue and organ defects with stem cell-based therapies being one of the best documented approaches. In the review, different biomaterials which are used in several methods to fabricate tissue engineering scaffolds were explained and show good properties (biocompatibility, biodegradability, and mechanical properties etc.) for cell migration and infiltration. Stem cell homing is a recruitment process for inducing the migration of the systemically transplanted cells, or host cells, to defect sites. The mechanisms and modes of stem cell homing-based tissue engineering can be divided into two types depending on the source of the stem cells: endogenous and exogenous. Exogenous stem cell-based bioactive scaffolds have the challenge of long-term culturing in vitro and for endogenous stem cells the biochemical signal homing recruitment mechanism is not clear yet. Although the stem cell homing-based bioactive scaffolds are attractive candidates for tissue defect therapies, based on in vitro studies and animal tests, there is still a long way before clinical application.

  5. Analytical SuperSTEM for extraterrestrial materials research

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, J P; Dai, Z R

    2009-09-08

    Electron-beam studies of extraterrestrial materials with significantly improved spatial resolution, energy resolution and sensitivity are enabled using a 300 keV SuperSTEM scanning transmission electron microscope with a monochromator and two spherical aberration correctors. The improved technical capabilities enable analyses previously not possible. Mineral structures can be directly imaged and analyzed with single-atomic-column resolution, liquids and implanted gases can be detected, and UV-VIS optical properties can be measured. Detection limits for minor/trace elements in thin (<100 nm thick) specimens are improved such that quantitative measurements of some extend to the sub-500 ppm level. Electron energy-loss spectroscopy (EELS) can be carried out with 0.10-0.20 eV energy resolution and atomic-scale spatial resolution such that variations in oxidation state from one atomic column to another can be detected. Petrographic mapping is extended down to the atomic scale using energy-dispersive x-ray spectroscopy (EDS) and energy-filtered transmission electron microscopy (EFTEM) imaging. Technical capabilities and examples of the applications of SuperSTEM to extraterrestrial materials are presented, including the UV spectral properties and organic carbon K-edge fine structure of carbonaceous matter in interplanetary dust particles (IDPs), x-ray elemental maps showing the nanometer-scale distribution of carbon within GEMS (glass with embedded metal and sulfides), the first detection and quantification of trace Ti in GEMS using EDS, and detection of molecular H{sub 2}O in vesicles and implanted H{sub 2} and He in irradiated mineral and glass grains.

  6. The effect of distal ulnar implant stem material and length on bone strains.

    Science.gov (United States)

    Austman, Rebecca L; Beaton, Brendon J B; Quenneville, Cheryl E; King, Graham J W; Gordon, Karen D; Dunning, Cynthia E

    2007-01-01

    Implant design parameters can greatly affect load transfer from the implant stem to the bone. We have investigated the effect of length or material of distal ulnar implant stems on the surrounding bone strains. Eight cadaveric ulnas were instrumented with 12 strain gauges and secured in a customized jig. Strain data were collected while loads (5-30 N) were applied to the medial surface of the native ulnar head. The native ulnar head was removed, and a stainless steel implant with an 8-cm-long finely threaded stem was cemented into the canal. After the cement had cured, the 8-cm stem was removed, leaving a threaded cement mantle in the canal that could accept shorter threaded stems of interest. The loading protocol was then repeated for stainless steel stems that were 7, 5, and 3 cm in length, as well as for a 5-cm-long titanium alloy (TiAl(6)V(4)) stem. Other stainless steel stem lengths between 3 and 7 cm were tested at intervals of 0.5 cm, with only a 20 N load applied. No stem length tested matched the native strains at all gauge locations. No significant differences were found between any stem length and the native bone at the 5th and 6th strain gauge positions. Strains were consistently closer to the native bone strains with the titanium stem than the stainless steel stem for each gauge pair that was positioned on the bone overlying the stem. The 3-cm stem results were closer to the native strains than the 7-cm stem for all loads at gauges locations that were on top of the stem. The results from this study suggest that the optimal stem characteristics for distal ulnar implants from a load transfer point of view are possessed by shorter (approximately 3 to 4 cm) titanium stems.

  7. Development and validation of science, technology, engineering and mathematics (STEM) based instructional material

    Science.gov (United States)

    Gustiani, Ineu; Widodo, Ari; Suwarma, Irma Rahma

    2017-05-01

    This study is intended to examine the development and validation of simple machines instructional material that developed based on Science, Technology, Engineering and Mathematics (STEM) framework that provides guidance to help students learn and practice for real life and enable individuals to use knowledge and skills they need to be an informed citizen. Sample of this study consist of one class of 8th grader at a junior secondary school in Bandung, Indonesia. To measure student learning, a pre-test and post-test were given before and after implementation of the STEM based instructional material. In addition, a questionnaire of readability was given to examine the clarity and difficulty level of each page of instructional material. A questionnaire of students' response towards instructional material given to students and teachers at the end of instructional material reading session to measure layout aspects, content aspects and utility aspects of instructional material for being used in the junior secondary school classroom setting. The results show that readability aspect and students' response towards STEM based instructional material of STEM based instructional material is categorized as very high. Pretest and posttest responses revealed that students retained significant amounts information upon completion of the STEM instructional material. Student overall learning gain is 0.67 which is categorized as moderate. In summary, STEM based instructional material that was developed is valid enough to be used as educational materials necessary for conducting effective STEM education.

  8. The performance of human dental pulp stem cells on different three-dimensional scaffold materials.

    NARCIS (Netherlands)

    Zhang, W.; Walboomers, X.F.; Kuppevelt, A.H.M.S.M. van; Daamen, W.F.; Bian, Z.; Jansen, J.A.

    2006-01-01

    The aim of this study was to investigate the in vitro and in vivo behavior of human dental pulp stem cells (DPSCs) isolated from impacted third molars, when seeded onto different 3-dimensional (3-D) scaffold materials: i.e. a spongeous collagen, a porous ceramic, and a fibrous titanium mesh.

  9. Osteogenic differentiation of dental pulp stem cells under the influence of three different materials

    DEFF Research Database (Denmark)

    Ajlan, S. A.; Ashri, N. Y.; Aldahmash, Abdullah M.

    2015-01-01

    Background: Regeneration of periodontal tissues is a major goal of periodontal therapy. Dental pulp stem cells (DPSCs) show mesenchymal cell properties with the potential for dental tissue engineering. Enamel matrix derivative (EMD) and platelet-derived growth factor (PDGF) are examples of materi......Background: Regeneration of periodontal tissues is a major goal of periodontal therapy. Dental pulp stem cells (DPSCs) show mesenchymal cell properties with the potential for dental tissue engineering. Enamel matrix derivative (EMD) and platelet-derived growth factor (PDGF) are examples...

  10. Synthetic Light-Curable Polymeric Materials Provide a Supportive Niche for Dental Pulp Stem Cells.

    Science.gov (United States)

    Vining, Kyle H; Scherba, Jacob C; Bever, Alaina M; Alexander, Morgan R; Celiz, Adam D; Mooney, David J

    2018-01-01

    Dental disease annually affects billions of patients, and while regenerative dentistry aims to heal dental tissue after injury, existing polymeric restorative materials, or fillings, do not directly participate in the healing process in a bioinstructive manner. There is a need for restorative materials that can support native functions of dental pulp stem cells (DPSCs), which are capable of regenerating dentin. A polymer microarray formed from commercially available monomers to rapidly identify materials that support DPSC adhesion is used. Based on these findings, thiol-ene chemistry is employed to achieve rapid light-curing and minimize residual monomer of the lead materials. Several triacrylate bulk polymers support DPSC adhesion, proliferation, and differentiation in vitro, and exhibit stiffness and tensile strength similar to existing dental materials. Conversely, materials composed of a trimethacrylate monomer or bisphenol A glycidyl methacrylate, which is a monomer standard in dental materials, do not support stem cell adhesion and negatively impact matrix and signaling pathways. Furthermore, thiol-ene polymerized triacrylates are used as permanent filling materials at the dentin-pulp interface in direct contact with irreversibly injured pulp tissue. These novel triacrylate-based biomaterials have potential to enable novel regenerative dental therapies in the clinic by both restoring teeth and providing a supportive niche for DPSCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Nanoscale definition of substrate materials to direct human adult stem cells towards tissue specific populations.

    Science.gov (United States)

    Curran, Judith M; Chen, Rui; Stokes, Robert; Irvine, Eleanor; Graham, Duncan; Gubbins, Earl; Delaney, Deany; Amro, Nabil; Sanedrin, Raymond; Jamil, Haris; Hunt, John A

    2010-03-01

    The development of homogenously nano-patterned chemically modified surfaces that can be used to initiate a cellular response, particularly stem cell differentiation, in a highly controlled manner without the need for exogenous biological factors has never been reported, due to that fact that precisely defined and reproducible systems have not been available that can be used to study cell/material interactions and unlock the potential of a material driven cell response. Until now material driven stem cell (furthermore any cell) responses have been variable due to the limitations in definition and reproducibility of the underlying substrate and the lack of true homogeneity of modifications that can dictate a cellular response at a sub-micron level that can effectively control initial cell interactions of all cells that contact the surface. Here we report the successful design and use of homogenously molecularly nanopatterned surfaces to control initial stem cell adhesion and hence function. The highly specified nano-patterned arrays were compared directly to silane modified bulk coated substrates that have previously been proven to initiate mesenchymal stem cell (MSC) differentiation in a heterogenous manner, the aim of this study was to prove the efficiency of these previously observed cell responses could be enhanced by the incorporation of nano-patterns. Nano-patterned surfaces were prepared by Dip Pen Nanolithography (DPN) to produce arrays of 70 nm sized dots separated by defined spacings of 140, 280 and 1000 nm with terminal functionalities of carboxyl, amino, methyl and hydroxyl and used to control cell growth. These nanopatterned surfaces exhibited unprecedented control of initial cell interactions and will change the capabilities for stem cell definition in vitro and then cell based medical therapies. In addition to highlighting the ability of the materials to control stem cell functionality on an unprecedented scale this research also introduces the

  12. Pretreated of banana pseudo-stem as raw material for enzymatic hydrolysis and bioethanol production

    Directory of Open Access Journals (Sweden)

    Kusmiyati

    2018-01-01

    Full Text Available Development of alternative energy is needed to solve the energy problem, including bioethanol. Banana pseudo-stem is a lignocellulose material that can used to produce bioethanol. Banana pseudo-stem has 28.83% cellulose and 19.39% lignin. The amount of lignin will reduce by pretreatment process. Variations of pretreatment methods by autoclaving of banana-pseudo stem in a steam, 0.5N, 1N, 1.5N, 2N NaOH solutions for 90 minutes were employed. Then the preteated samples were further enzymatic hydrolysed for 24, 48, 72 hours. The fermentation method of simultaneous saccharification and fermentation (SSF was applied using cellulase enzyme and yeast of Saccharomyces cerevisiae for 120 hours. The variation of the pretreatment process by increasing of NaOH concentration solutions led to decreased the lignin content while increased in cellulose content. The lowest lignin content was 11.44% and the highest cellulose was 51.66%. The highest sugar content was 29.8 g/L (at pretreatment 2N NaOH solution, 72 hours hydrolysis. The highest bioethanol amount (4.32 g/L was produced from pretreated banana stem using 2N NaOH solution.

  13. STEM LEARNING IN MATERIAL OF TEMPERATURE AND ITS CHANGE TO IMPROVE SCIENTIFIC LITERACY OF JUNIOR HIGH SCHOOL

    Directory of Open Access Journals (Sweden)

    N. Khaeroningtyas

    2016-04-01

    Full Text Available This research aims to determine the improvement of students’ scientific literacy after STEM (Science, Technology, Engineering, and Mathematics learning using 6E Learning by DesignTM Model on temperature and its changes material. The research was conducted in SMP Negeri (State Junior High School 1 Bumiayu in the academic year 2015/2016. The method used was quasi-experimental design with The Matching Only - pretest posttest control group design. This study used two group of experiment group of students who learned the material with STEM learning using 6E Learning by DesignTM, while the control group students learned with non-STEM learning. The analysis showed that the students' scientific literacy in experiment group is better than control group. The conclusion that can be drawn is STEM learning using 6E Learning by DesignTM on temperature and its changes material can improve students’ scientific literacy.

  14. The development of learning material using learning cycle 5E model based stem to improve students’ learning outcomes in Thermochemistry

    Science.gov (United States)

    sugiarti, A. C.; suyatno, S.; Sanjaya, I. G. M.

    2018-04-01

    The objective of this study is describing the feasibility of Learning Cycle 5E STEM (Science, Technology, Engineering, and Mathematics) based learning material which is appropriate to improve students’ learning achievement in Thermochemistry. The study design used 4-D models and one group pretest-posttest design to obtain the information about the improvement of sudents’ learning outcomes. The subject was learning cycle 5E based STEM learning materials which the data were collected from 30 students of Science class at 11th Grade. The techniques used in this study were validation, observation, test, and questionnaire. Some result attain: (1) all the learning materials contents were valid, (2) the practicality and the effectiveness of all the learning materials contents were classified as good. The conclution of this study based on those three condition, the Learnig Cycle 5E based STEM learning materials is appropriate to improve students’ learning outcomes in studying Thermochemistry.

  15. Cellular Responses in Human Dental Pulp Stem Cells Treated with Three Endodontic Materials

    Directory of Open Access Journals (Sweden)

    Alejandro Victoria-Escandell

    2017-01-01

    Full Text Available Human dental pulp stem cells (HDPSCs are of special relevance in future regenerative dental therapies. Characterizing cytotoxicity and genotoxicity produced by endodontic materials is required to evaluate the potential for regeneration of injured tissues in future strategies combining regenerative and root canal therapies. This study explores the cytotoxicity and genotoxicity mediated by oxidative stress of three endodontic materials that are widely used on HDPSCs: a mineral trioxide aggregate (MTA-Angelus white, an epoxy resin sealant (AH-Plus cement, and an MTA-based cement sealer (MTA-Fillapex. Cell viability and cell death rate were assessed by flow cytometry. Oxidative stress was measured by OxyBlot. Levels of antioxidant enzymes were evaluated by Western blot. Genotoxicity was studied by quantifying the expression levels of DNA damage sensors such as ATM and RAD53 genes and DNA damage repair sensors such as RAD51 and PARP-1. Results indicate that AH-Plus increased apoptosis, oxidative stress, and genotoxicity markers in HDPSCs. MTA-Fillapex was the most cytotoxic oxidative stress inductor and genotoxic material for HDPSCs at longer times in preincubated cell culture medium, and MTA-Angelus was less cytotoxic and genotoxic than AH-Plus and MTA-Fillapex at all times assayed.

  16. Biological Effects of Provisional Resin Materials on Human Dental Pulp Stem Cells.

    Science.gov (United States)

    Jun, S-K; Mahapatra, C; Lee, H-H; Kim, H-W; Lee, J-H

    This study investigated the in vitro cytotoxicity as well as the proinflammatory cytokine expression of provisional resin materials on primary cultured human dental pulp stem cells (hDPSCs). Five commercially available provisional resin materials were chosen (SNAP [SN], Luxatemp [LT], Jet [JE], Revotek LC [RL], and Vipi block [VB]). Eluates that were either polymerizing or already set were added to hDPSCs under serially diluted conditions divided into three different setting times (25% set, 50% set, and 100% set) and incubated for 24 hours with 2× concentrated culture media. Cell cytotoxicity tests were performed by LDH assay and live and dead confocal microscope images. The expression of proinflammatory cytokines in SN and VB was measured using cytokine antibody arrays. Data were analyzed using repeated measures analysis of variance (ANOVA) or ANOVA followed by the Tukey post hoc test at a significance level of pprovisional resin materials during polymerization (SN, LT, and JE) were cytotoxic to hDPSCs and may adversely affect pulp tissue.

  17. Squaramide-based supramolecular materials for three-dimensional cell culture of human induced pluripotent stem cells and their derivatives

    NARCIS (Netherlands)

    Tong, Ciqing; Liu, Tingxian; Saez Talens, Victorio; Noteborn, Willem E.M.; Sharp, Thomas H.; Hendrix, Marco M.R.M.; Voets, Ilja K.; Mummery, Christine L.; Orlova, Valeria V.; Kieltyka, Roxanne E.

    2018-01-01

    Synthetic hydrogel materials can recapitulate the natural cell microenvironment; however, it is equally necessary that the gels maintain cell viability and phenotype while permitting reisolation without stress, especially for use in the stem cell field. Here, we describe a family of synthetically

  18. Long-term performance of thermoplastic composite material with cotton burr and stem (CBS) as a partial filler

    Science.gov (United States)

    Rationale: Cotton burr and stem (CBS) fraction of cotton gin byproducts has shown promise as a fiber filler in thermoplastic composites, with physical and mechanical properties comparable to that made with wood fiber fillers. However, the long-term performance of this composite material is not known...

  19. STEM LEARNING IN MATERIAL OF TEMPERATURE AND ITS CHANGE TO IMPROVE SCIENTIFIC LITERACY OF JUNIOR HIGH SCHOOL

    OpenAIRE

    N. Khaeroningtyas; A. Permanasari; I. Hamidah

    2016-01-01

    This research aims to determine the improvement of students’ scientific literacy after STEM (Science, Technology, Engineering, and Mathematics) learning using 6E Learning by DesignTM Model on temperature and its changes material. The research was conducted in SMP Negeri (State Junior High School) 1 Bumiayu in the academic year 2015/2016. The method used was quasi-experimental design with The Matching Only - pretest posttest control group design. This study used two group of experiment group o...

  20. Impact of starting material (fresh versus cryopreserved marrow) on mesenchymal stem cell culture.

    Science.gov (United States)

    Kaplan, Alesia; Sackett, Katie; Sumstad, Darin; Kadidlo, Dianne; McKenna, David H

    2017-09-01

    Mesenchymal stem cells (MSCs) continue to be investigated in multiple clinical trials as potential therapy for different disorders. There is ongoing controversy surrounding the clinical use of cryopreserved versus fresh MSCs. However, little is known about how cryopreservation affects marrow as starting material. The growth kinetics of MSC cultures derived from fresh versus cryopreserved marrow were compared. Data were reviewed on the growth kinetics of MSCs derived from fresh versus cryopreserved marrow of nine donors. Marrow harvested from each donor was separated into four aliquots (one fresh and three cryopreserved for culture). Data on the date of mononuclear cell cryopreservation/thaw, MSC counts at Passages 1 and 2, MSC doubling, MSC fold expansion, viability (of mononuclear cells and final MSCs), and on flow cytometry markers of mononuclear cells and final MSCs were analyzed for the fresh and cryopreserved marrow groups. In total, 21 MSC lots (seven fresh and 14 cryopreserved) were obtained. The average age of cryopreserved mononuclear cell product was 295 days (range, 18-1241 days). There were no significant differences between MSC numbers at Passage 1 (p = 0.1), final MSC numbers (p = 0.5), MSC doubling (p = 0.7), or MSC fold expansion (p = 0.7). A significant difference was observed in viability by flow cytometry for both mononuclear cells (p = 0.002) and final MSCs (p = 0.009), with higher viability in the fresh marrow group. This study demonstrates that MSCs derived from cryopreserved marrow have the same growth characteristics as fresh marrow-derived MSCs. Further studies are needed to explore potential differences in clinical efficacy. © 2017 AABB.

  1. In vitro mesenchymal stem cell response to a CO{sub 2} laser modified polymeric material

    Energy Technology Data Exchange (ETDEWEB)

    Waugh, D.G., E-mail: d.waugh@chester.ac.uk [Laser Engineering and Manufacturing Research Centre, Faculty of Science and Engineering, University of Chester, Chester CH1 4BJ (United Kingdom); Hussain, I. [School of Life Sciences, Brayford Pool, University of Lincoln, Lincoln LN6 7TS (United Kingdom); Lawrence, J.; Smith, G.C. [Laser Engineering and Manufacturing Research Centre, Faculty of Science and Engineering, University of Chester, Chester CH1 4BJ (United Kingdom); Cosgrove, D. [School of Life Sciences, Brayford Pool, University of Lincoln, Lincoln LN6 7TS (United Kingdom); Toccaceli, C. [Laser Engineering and Manufacturing Research Centre, Faculty of Science and Engineering, University of Chester, Chester CH1 4BJ (United Kingdom)

    2016-10-01

    With an ageing world population it is becoming significantly apparent that there is a need to produce implants and platforms to manipulate stem cell growth on a pharmaceutical scale. This is needed to meet the socio-economic demands of many countries worldwide. This paper details one of the first ever studies in to the manipulation of stem cell growth on CO{sub 2} laser surface treated nylon 6,6 highlighting its potential as an inexpensive platform to manipulate stem cell growth on a pharmaceutical scale. Through CO{sub 2} laser surface treatment discrete changes to the surfaces were made. That is, the surface roughness of the nylon 6,6 was increased by up to 4.3 μm, the contact angle was modulated by up to 5° and the surface oxygen content increased by up to 1 atom %. Following mesenchymal stem cell growth on the laser treated samples, it was identified that CO{sub 2} laser surface treatment gave rise to an enhanced response with an increase in viable cell count of up to 60,000 cells/ml when compared to the as-received sample. The effect of surface parameters modified by the CO{sub 2} laser surface treatment on the mesenchymal stem cell response is also discussed along with potential trends that could be identified to govern the mesenchymal stem cell response.

  2. Prospecting for Energy-Rich Renewable Raw Materials: Sorghum Stem Case Study.

    Directory of Open Access Journals (Sweden)

    Caitlin S Byrt

    Full Text Available Sorghum vegetative tissues are becoming increasingly important for biofuel production. The composition of sorghum stem tissues is influenced by genotype, environment and photoperiod sensitivity, and varies widely between varieties and also between different stem tissues (outer rind vs inner pith. Here, the amount of cellulose, (1,3;1,4-β-glucan, arabinose and xylose in the stems of twelve diverse sorghum varieties, including four photoperiod-sensitive varieties, was measured. At maturity, most photoperiod-insensitive lines had 1% w/w (1,3;1,4-β-glucan in stem pith tissue whilst photoperiod-sensitive varieties remained in a vegetative stage and accumulated up to 6% w/w (1,3;1,4-β-glucan in the same tissue. Three sorghum lines were chosen for further study: a cultivated grain variety (Sorghum bicolor BTx623, a sweet variety (S. bicolor Rio and a photoperiod-sensitive wild line (S. bicolor ssp. verticilliflorum Arun. The Arun line accumulated 5.5% w/w (1,3;1,4-β-glucan and had higher SbCslF6 and SbCslH3 transcript levels in pith tissues than did photoperiod-insensitive varieties Rio and BTx623 (<1% w/w pith (1,3;1,4-β-glucan. To assess the digestibility of the three varieties, stem tissue was treated with either hydrolytic enzymes or dilute acid and the release of fermentable glucose was determined. Despite having the highest lignin content, Arun yielded significantly more glucose than the other varieties, and theoretical calculation of ethanol yields was 10 344 L ha-1 from this sorghum stem tissue. These data indicate that sorghum stem (1,3;1,4-β-glucan content may have a significant effect on digestibility and bioethanol yields. This information opens new avenues of research to generate sorghum lines optimised for biofuel production.

  3. Prospecting for Energy-Rich Renewable Raw Materials: Sorghum Stem Case Study.

    Science.gov (United States)

    Byrt, Caitlin S; Betts, Natalie S; Tan, Hwei-Ting; Lim, Wai Li; Ermawar, Riksfardini A; Nguyen, Hai Yen; Shirley, Neil J; Lahnstein, Jelle; Corbin, Kendall; Fincher, Geoffrey B; Knauf, Vic; Burton, Rachel A

    2016-01-01

    Sorghum vegetative tissues are becoming increasingly important for biofuel production. The composition of sorghum stem tissues is influenced by genotype, environment and photoperiod sensitivity, and varies widely between varieties and also between different stem tissues (outer rind vs inner pith). Here, the amount of cellulose, (1,3;1,4)-β-glucan, arabinose and xylose in the stems of twelve diverse sorghum varieties, including four photoperiod-sensitive varieties, was measured. At maturity, most photoperiod-insensitive lines had 1% w/w (1,3;1,4)-β-glucan in stem pith tissue whilst photoperiod-sensitive varieties remained in a vegetative stage and accumulated up to 6% w/w (1,3;1,4)-β-glucan in the same tissue. Three sorghum lines were chosen for further study: a cultivated grain variety (Sorghum bicolor BTx623), a sweet variety (S. bicolor Rio) and a photoperiod-sensitive wild line (S. bicolor ssp. verticilliflorum Arun). The Arun line accumulated 5.5% w/w (1,3;1,4)-β-glucan and had higher SbCslF6 and SbCslH3 transcript levels in pith tissues than did photoperiod-insensitive varieties Rio and BTx623 (<1% w/w pith (1,3;1,4)-β-glucan). To assess the digestibility of the three varieties, stem tissue was treated with either hydrolytic enzymes or dilute acid and the release of fermentable glucose was determined. Despite having the highest lignin content, Arun yielded significantly more glucose than the other varieties, and theoretical calculation of ethanol yields was 10 344 L ha-1 from this sorghum stem tissue. These data indicate that sorghum stem (1,3;1,4)-β-glucan content may have a significant effect on digestibility and bioethanol yields. This information opens new avenues of research to generate sorghum lines optimised for biofuel production.

  4. Modulation of Host Osseointegration during Bone Regeneration by Controlling Exogenous Stem Cells Differentiation Using a Material Approach.

    Science.gov (United States)

    Yu, Xiaohua; Wang, Liping; Xia, Zengmin; Chen, Li; Jiang, Xi; Rowe, David; Wei, Mei

    2014-02-01

    Stem cell-based tissue engineering for large bone defect healing has attracted enormous attention in regenerative medicine. However, sufficient osseointegration of the grafts combined with exogenous stem cells still remains a major challenge. Here we developed a material approach to modulate the integration of the grafts to the host tissue when exogenous bone marrow stromal cells (BMSCs) were used as donor cells. Distinctive osseointegration of bone grafts was observed as we varied the content of hydroxyapatite (HA) in the tissue scaffolds implanted in a mouse femur model. More than 80% of new bone was formed in the first two weeks of implantation in high HA content scaffold but lack of host integration while only less than 5% of the new bone was formed during this time period in the no HA group but with much stronger host integration. Cell origin analysis leveraging GFP reporter indicates new bone in HA containing groups was mainly derived from donor BMSCs. In comparison, both host and donor cells were found on new bone surface in the no HA groups which led to seamless bridging between host tissue and the scaffold. Most importantly, host integration during bone formation is closely dictated to the content of HA present in the scaffolds. Taken together, we demonstrate a material approach to modulate the osseointegration of bone grafts in the context of exogenous stem cell-based bone healing strategy which might lead to fully functional bone tissue regeneration.

  5. Development of Synthetic and Natural Materials for Tissue Engineering Applications Using Adipose Stem Cells

    Directory of Open Access Journals (Sweden)

    Yunfan He

    2016-01-01

    Full Text Available Adipose stem cells have prominent implications in tissue regeneration due to their abundance and relative ease of harvest from adipose tissue and their abilities to differentiate into mature cells of various tissue lineages and secrete various growth cytokines. Development of tissue engineering techniques in combination with various carrier scaffolds and adipose stem cells offers great potential in overcoming the existing limitations constraining classical approaches used in plastic and reconstructive surgery. However, as most tissue engineering techniques are new and highly experimental, there are still many practical challenges that must be overcome before laboratory research can lead to large-scale clinical applications. Tissue engineering is currently a growing field of medical research; in this review, we will discuss the progress in research on biomaterials and scaffolds for tissue engineering applications using adipose stem cells.

  6. Comparative study of P19 EC stem cell differentiation in between conventional hanging drop and the zebrafish chorion as a bio-derived material.

    Science.gov (United States)

    Dae Seok Na; Lee, Hwang; Sun Uk Kim; Chang Nam Hwang; Sang Ho Lee; Ji Yoon Kang; Jai Kyeong Kim; James Jungho Pak

    2008-07-01

    Various materials including glass and polymers have been widely used for stem cell culture due to their biocompatibility. However, the roles of these materials are fundamentally limited because they cannot realize or imitate the complex biological functions of living tissues, except in very simple cases. Here, the development of a bio-derived material suitable for stem cell culture and improvement of differentiation efficiency to specific cell lineages with no stimulating agents by using a chorion obtained from a fertilized zebrafish egg through the removal of the yolk and embryonic cell mass from the egg is reported. Mouse P19 EC stem cells introduced into the empty chorion form a uniform embryoid body (EB) without addition of any inducing agent. It is demonstrated that the zebrafish chorion with nanopores improves efficiencies greatly in the EB formation, cell proliferation, and lineage-specific differentiations compared to those of the conventional hanging drop culture method.

  7. The effects of nanophase ceramic materials on select functions of human mesenchymal stem cells

    Science.gov (United States)

    Dulgar-Tulloch, Aaron Joseph

    2005-11-01

    Modification of the chemistry and surface topography of nanophase ceramics can provide biomaterial formulations capable of directing the functions of adherent cells. This effect relies on the type, amount, and conformation of adsorbed proteins that mediate the adhesion of mesenchymally-descended lineages. The mechanisms driving this response are not yet well-understood and have not been investigated for human mesenchymal stem cells (HMSCs), a progenitor-lineage critical to orthopaedic biomaterials. The present study addressed these needs by examining the in vitro adhesion, proliferation, and osteogenic differentiation of HMSCs as a function of substrate chemistry and grain size, with particular attention to the protein-mediated mechanisms of cell adhesion. Alumina, titania, and hydroxyapatite substrates were prepared with 1500, 200, 50, and 24 (alumina only) nm grain sizes, and characterized with respect to surface properties, porosity, composition, and phase. Adhesion of HMSCs was dependent upon both chemistry and grain size. Specifically, adhesion on alumina and hydroxyapatite was reduced on 50 and 24 (alumina only) nm surfaces, as compared to 1500 and 200 nm surfaces, while adhesion on titania substrates was independent of grain size. Investigation into the protein-mediated mechanisms of this response identified vitronectin as the dominant adhesive protein, demonstrated random protein distribution across the substrate surface without aggregation or segregation, and confirmed the importance of the type, amount, and conformation of adsorbed proteins in cell adhesion. Minimal cell proliferation was observed on 50 and 24 (alumina only) nm substrates of any chemistry. Furthermore, cell proliferation was up-regulated on 200 nm substrates after 7 days of culture. Osteogenic differentiation was not detected on 50 nm substrates throughout the 28 day culture period. In contrast, osteogenic differentiation was strongly enhanced on 200 nm substrates, occurring approximately

  8. Large field of view quantitative phase imaging of induced pluripotent stem cells and optical pathlength reference materials

    Science.gov (United States)

    Kwee, Edward; Peterson, Alexander; Stinson, Jeffrey; Halter, Michael; Yu, Liya; Majurski, Michael; Chalfoun, Joe; Bajcsy, Peter; Elliott, John

    2018-02-01

    Induced pluripotent stem cells (iPSCs) are reprogrammed cells that can have heterogeneous biological potential. Quality assurance metrics of reprogrammed iPSCs will be critical to ensure reliable use in cell therapies and personalized diagnostic tests. We present a quantitative phase imaging (QPI) workflow which includes acquisition, processing, and stitching multiple adjacent image tiles across a large field of view (LFOV) of a culture vessel. Low magnification image tiles (10x) were acquired with a Phasics SID4BIO camera on a Zeiss microscope. iPSC cultures were maintained using a custom stage incubator on an automated stage. We implement an image acquisition strategy that compensates for non-flat illumination wavefronts to enable imaging of an entire well plate, including the meniscus region normally obscured in Zernike phase contrast imaging. Polynomial fitting and background mode correction was implemented to enable comparability and stitching between multiple tiles. LFOV imaging of reference materials indicated that image acquisition and processing strategies did not affect quantitative phase measurements across the LFOV. Analysis of iPSC colony images demonstrated mass doubling time was significantly different than area doubling time. These measurements were benchmarked with prototype microsphere beads and etched-glass gratings with specified spatial dimensions designed to be QPI reference materials with optical pathlength shifts suitable for cell microscopy. This QPI workflow and the use of reference materials can provide non-destructive traceable imaging method for novel iPSC heterogeneity characterization.

  9. Functionalized carbon nanotubes as suitable scaffold materials for proliferation and differentiation of canine mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Das K

    2017-04-01

    Full Text Available Kinsuk Das,1 AP Madhusoodan,1 Bhabesh Mili,1 Ajay Kumar,2 AC Saxena,3 Kuldeep Kumar,1 Mihir Sarkar,1 Praveen Singh,4 Sameer Srivastava,5 Sadhan Bag1 1Division of Physiology and Climatology, 2Biochemistry and Food Science Section, 3Division of Surgery, 4Biophysics, Electron Microscopy and Instrumentation Section, 5Division of Veterinary Biotechnology, Indian Council of Agricultural Research – Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, India Abstract: In the field of regenerative medicine, numerous potential applications of mesenchymal stem cells (MSCs can be envisaged, due to their ability to differentiate into a range of tissues on the basis of the substrate on which they grow. With the advances in nanotechnology, carbon nanotubes (CNTs have been widely explored for use as cell culture substrate in tissue engineering applications. In this study, canine bone marrow-derived MSCs were considered as the cellular model for an in vitro study to elucidate the collective cellular processes, using three different varieties of thin films of functionalized carbon nanotubes (COOH-single-walled CNTs [SWCNTs], COOH-multiwalled CNTs [MWCNTs] and polyethylene glycol [PEG]-SWCNTs, which were spray dried onto preheated cover slips. Cells spread out better on the CNT films, resulting in higher cell surface area and occurrence of filopodia, with parallel orientation of stress fiber bundles. Canine MSCs proliferated at a slower rate on all types of CNT substrates compared to the control, but no decline in cell number was noticed during the study period. Expression of apoptosis-associated genes decreased on the CNT substrates as time progressed. On flow cytometry after AnnexinV-fluorescein isothiocyanate/propidium iodide (PI staining, total number of apoptotic and necrotic cells remained lower in COOH-functionalized films compared to PEG-functionalized ones. Collectively, these results indicate that COOH-MWCNT substrate provided an

  10. Graphene-supporting films and low-voltage STEM in SEM toward imaging nanobio materials without staining: Observation of insulin amyloid fibrils.

    Science.gov (United States)

    Ogawa, Takashi; Gang, Geun Won; Thieu, Minh Thu; Kwon, Hyuksang; Ahn, Sang Jung; Ha, Tai Hwan; Cho, Boklae

    2017-05-01

    Utilization of graphene-supporting films and low-voltage scanning transmission electron microscopy (LV-STEM) in scanning electron microscopy (SEM) is shown to be an effective means of observing unstained nanobio materials. Insulin amyloid fibrils, which are implicated as a cause of type II diabetes, are formed in vitro and observed without staining at room temperature. An in-lens cold field-emission SEM, equipped with an additional homemade STEM detector, provides dark field (DF)-STEM images in the low energy range of 5-30keV, together with secondary electron (SE) images. Analysis based on Lenz's theory is used to interpret the experimental results. Graphene films, where the fibrils are deposited, reduce the background level of the STEM images compared with instances when conventional amorphous carbon films are used. Using 30keV, which is lower than that for conventional TEM (100-300keV), together with low detection angles (15-55mrad) enhances the signals from the fibrils. These factors improve image quality, which enables observation of thin fibrils with widths of 7-8nm. STEM imaging clearly reveals a twisted-ribbon structure of a fibril, and SE imaging shows an emphasized striped pattern of the fibril. The LV-STEM in SEM enables acquisition of two types of images of an identical fibril in a single instrument, which is useful for understanding the structure. This study expands the application of SEM to other systems of interest, which is beneficial to a large number of users. The method in this study can be applied to the observation of various nanobio materials and analysis of their native structures, thus contributing to research in materials and life sciences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Application of image processing to STEM tomography of low-contrast materials

    International Nuclear Information System (INIS)

    Ortalan, V.; Herrera, M.; Morgan, D.G.; Browning, N.D.

    2009-01-01

    In this study, the effect of various image-processing techniques on the visibility of tomographic reconstructions is investigated for a low-contrast material system of non-uniform thickness containing complex features such as grain boundaries and nanoparticles. Starting with a tilt series of high-angle annular dark-field (HAADF) images from an area of Dy-doped YBa 2 Cu 3 O 7-x -coated superconductor obtained using a scanning transmission electron microscope, various image-processing techniques were applied. These can be classified as edge detection, contrast-enhancing methods for non-uniform thickness and image sharpening. Although the processing methods violate the projection criterion for tomographic reconstruction, they were found, at least in this case, to enhance contrast and define the correct shape and size of structural features with minimal artifacts. Enhancing the visibility of structural features in this way allows the spatial distribution of the nanoparticles, their size, number density and location relative to each other and grain boundaries to be determined, which are essential to understand the flux-pinning characteristics of these materials.

  12. Bioengineering of cultured epidermis from adult epidermal stem cells using Mebio gel sutable as autologous graft material

    Directory of Open Access Journals (Sweden)

    Lakshmana K Yerneni

    2007-01-01

    Full Text Available Closure of burn wound is the primary requirement in order to reduce morbidity and mortality that are otherwise very high due to non-availability of permanent wound covering materials. Sheets of cultured epidermis grown from autologous epidermal keratinocyte stem cells are accepted world over as one of the best wound covering materials. In a largely populated country like ours where burn casualties occur more frequently due to inadequate safety practices, there is a need for indigenous research inputs to develop such methodologies. The technique to culturing epidermal sheets in vitro involves the basic Reheinwald-Green method with our own beneficial inputs. The technique employs attenuated 3T3 cells as feeders for propagating keratinocyte stem cells that are isolated from the epidermis of an initial skin biopsy of about 5 cm2 from the patient. The cultures are then maintained in Dulbecco's modified Eagle's medium strengthened with Ham's F12 formula, bovine fetal serum and various specific growth-promoting agents and factors in culture flasks under standard culture conditions. The primary cultures thus established would be serially passaged to achieve the required expansion. Our major inputs are into the establishment of (1 an efficient differential trypsinization protocol to isolate large number epidermal keratinocytes from the skin biopsy, (2 a highly specific, unique and foolproof attenuation protocol for 3T3 cells and (3 a specialized and significant decontamination protocol. The fully formed epidermal sheet as verified by immuno-histochemical and light & electron microscopic studies, is lifted on to paraffin gauze by incubating in a neutral protease. The graft is then ready to be transported to the operating theatre for autologous application. We have a capability of growing cultured epidermal sheets sufficient enough to cover 40 per cent burn wound in 28 days. The preliminary small area clinical applications undertaken so far revealed

  13. Application of stem-cell media to explant culture of human periosteum: An optimal approach for preparing osteogenic cell material.

    Science.gov (United States)

    Uematsu, Kohya; Nagata, Masaki; Kawase, Tomoyuki; Suzuki, Kenji; Takagi, Ritsuo

    2013-01-01

    As part of our clinical tests on bone regeneration using cultured periosteal sheets, here, we prepared cultured periosteal sheets in two types of stem-cell culture media, STK1 and STK3. Human periosteum was expanded either in 1% human serum-supplemented STK1 for 28 days, in 1% human serum-supplemented STK1 for 14 days followed by 1% human serum-supplemented STK3 for 14 days (1% human serum-supplemented STK1+3), or in 10% fetal bovine serum-supplemented Medium 199 for 28 days (control). Cultured periosteal sheet diameter and DNA content were significantly higher, and the multilayer structure was prominent in 1% human serum-supplemented STK1 and 1% human serum-supplemented STK1+3. The messenger RNA of osteoblastic markers was significantly upregulated in 1% human serum-supplemented STK1+3. Osteopontin-immunopositive staining and mineralization were evident across a wide area of the cultured periosteal sheet in 1% human serum-supplemented STK1+3. Subcutaneous implantation in nude mice following expansion in 1% human serum-supplemented STK1+3 produced the highest cultured periosteal sheet osteogenic activity. Expansion in 1% human serum-supplemented STK1+3 successfully induced cultured periosteal sheet growth while retaining osteogenic potential, and subsequent osteoblastic induction promoted the production of homogeneous cell material.

  14. The Biomineralization of a Bioactive Glass-Incorporated Light-Curable Pulp Capping Material Using Human Dental Pulp Stem Cells

    Directory of Open Access Journals (Sweden)

    Soo-Kyung Jun

    2017-01-01

    Full Text Available The aim of this study was to investigate the biomineralization of a newly introduced bioactive glass-incorporated light-curable pulp capping material using human dental pulp stem cells (hDPSCs. The product (Bioactive® [BA] was compared with a conventional calcium hydroxide-incorporated (Dycal [DC] and a light-curable (Theracal® [TC] counterpart. Eluates from set specimens were used for investigating the cytotoxicity and biomineralization ability, determined by alkaline phosphatase (ALP activity and alizarin red staining (ARS. Cations and hydroxide ions in the extracts were measured. An hDPSC viability of less than 70% was observed with 50% diluted extract in all groups and with 25% diluted extract in the DC. Culturing with 12.5% diluted BA extract statistically lowered ALP activity and biomineralization compared to DC (p0.05. Ca (~110 ppm and hydroxide ions (pH 11 were only detected in DC and TC. Ionic supplement-added BA, which contained similar ion concentrations as TC, showed similar ARS mineralization compared to TC. In conclusion, the BA was similar to, yet more cytotoxic to hDPSCs than, its DC and TC. The BA was considered to stimulate biomineralization similar to DC and TC only when it released a similar amount of Ca and hydroxide ions.

  15. Stem Cells

    Science.gov (United States)

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  16. Effect of raw material particle-size distribution on combustion characteristics of stem wood pellets; Paaverkan av partikelfraktionsfoerdelningen paa utbraenningshastigheten hos traepellets vid nyttjande av olika soenderdelningsmetoder

    Energy Technology Data Exchange (ETDEWEB)

    Israelsson, Samuel; Henriksson, Gunnar; Boman, Christoffer; Oehman, Marcus

    2007-01-15

    The objective of the project was to determine the effect of raw material particle-size distribution on combustion characteristics of stem wood pellets. Several well defined pellet qualities were produced from raw materials (stem wood of pine and spruce) which had both different particle-size distributions and were produced with different milling equipments (hammer mill/refiner). The pellets were produced in a traditional (bench-scale) pellet mill and in a laboratory pellet mill/press. The combustion characteristics of the individual pellets were determined in a laboratory scale oven. Char yield, -shrinkage, -density and the micro pore volume of the produced char were also determined. Differences in total conversion times of approximately 5 % at experimental condition relevant for typical pellets equipment were determined for the different pellet qualities. The underlying reasons for the obtained differences in the combustion characteristics between the different pellet qualities are discussed in the report

  17. Gelatin-Derived Graphene–Silicate Hybrid Materials Are Biocompatible and Synergistically Promote BMP9-Induced Osteogenic Differentiation of Mesenchymal Stem Cells

    Energy Technology Data Exchange (ETDEWEB)

    Zou, Yulong [Department of Orthopaedic; Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Qazvini, Nader Taheri [Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States; Argonne National Laboratory, Argonne, Illinois 60439, United States; Zane, Kylie [Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States; Sadati, Monirosadat [Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States; Argonne National Laboratory, Argonne, Illinois 60439, United States; Wei, Qiang [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Liao, Junyi [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Fan, Jiaming [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Song, Dongzhe [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Department of Conservative Dentistry and Endodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China; Liu, Jianxiang [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Department; amp, Technology, Wuhan 430022, China; Ma, Chao [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Departments of Neurosurgery and Otolaryngology-Head; amp, Neck Surgery, The Affiliated Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Qu, Xiangyang [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Chen, Liqun [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Yu, Xinyi [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Zhang, Zhicai [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Department; amp, Technology, Wuhan 430022, China; Zhao, Chen [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Zeng, Zongyue [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Zhang, Ruyi [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Yan, Shujuan [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Wu, Tingting [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Departments of Neurosurgery and Otolaryngology-Head; amp, Neck Surgery, The Affiliated Zhongnan Hospital of Wuhan University, Wuhan 430071, China; Wu, Xingye [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Shu, Yi [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Li, Yasha [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; Zhang, Wenwen [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Department; Reid, Russell R. [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Department of Surgery, Section of Plastic; Lee, Michael J. [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Wolf, Jennifer Moritis [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Tirrell, Matthew [Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States; Argonne National Laboratory, Argonne, Illinois 60439, United States; He, Tong-Chuan [Molecular Oncology Laboratory, Department of Orthopaedic Surgery and Rehabilitation Medicine, The University of Chicago Medical Center, Chicago, Illinois 60637, United States; Ministry of Education Key Laboratory of; de Pablo, Juan J. [Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, United States; Argonne National Laboratory, Argonne, Illinois 60439, United States; Deng, Zhong-Liang [Department of Orthopaedic

    2017-05-04

    Graphene-based materials are used in many fields but have found only limited applications in biomedicine, including bone tissue engineering. Here, we demonstrate that novel hybrid materials consisting of gelatin-derived graphene and silicate nanosheets of Laponite (GL) are biocompatible and promote osteogenic differentiation of mesenchymal stem cells (MSCs). Homogeneous cell attachment, long-term proliferation, and osteogenic differentiation of MSCs on a GL-scaffold were confirmed using optical microscopy and scanning electron microscopy. GL-powders made by pulverizing the GL-scaffold were shown to promote bone morphogenetic protein (BMP9)-induced osteogenic differentiation. GL-powders increased the alkaline phosphatase (ALP) activity in immortalized mouse embryonic fibroblasts but decreased the ALP activity in more-differentiated immortalized mouse adipose-derived cells. Note, however, that GL-powders promoted BMP9-induced calcium mineral deposits in both MSC lines, as assessed using qualitative and quantitative alizarin red assays. Furthermore, the expression of chondro-osteogenic regulator markers such as Runx2, Sox9, osteopontin, and osteocalcin was upregulated by the GL-powder, independent of BMP9 stimulation; although the powder synergistically upregulated the BMP9-induced Osterix expression, the adipogenic marker PPAR gamma was unaffected. Furthermore, in vivo stem cell implantation experiments demonstrated that GL-powder could significantly enhance the BMP9-induced ectopic bone formation from MSCs. Collectively, our results strongly suggest that the GL hybrid materials promote BMP9-induced osteogenic differentiation of MSCs and hold promise for the development of bone tissue engineering platforms.

  18. Development and Analysis of New 3D Tactile Materials for the Enhancement of STEM Education for the Blind and Visually Impaired

    Science.gov (United States)

    Gonzales, Ashleigh

    Blind and visually impaired individuals have historically demonstrated a low participation in the fields of science, engineering, mathematics, and technology (STEM). This low participation is reflected in both their education and career choices. Despite the establishment of the Americans with Disabilities Act (ADA) and the Individuals with Disabilities Education Act (IDEA), blind and visually impaired (BVI) students continue to academically fall below the level of their sighted peers in the areas of science and math. Although this deficit is created by many factors, this study focuses on the lack of adequate accessible image based materials. Traditional methods for creating accessible image materials for the vision impaired have included detailed verbal descriptions accompanying an image or conversion into a simplified tactile graphic. It is very common that no substitute materials will be provided to students within STEM courses because they are image rich disciplines and often include a large number images, diagrams and charts. Additionally, images that are translated into text or simplified into basic line drawings are frequently inadequate because they rely on the interpretations of resource personnel who do not have expertise in STEM. Within this study, a method to create a new type of tactile 3D image was developed using High Density Polyethylene (HDPE) and Computer Numeric Control (CNC) milling. These tactile image boards preserve high levels of detail when compared to the original print image. To determine the discernibility and effectiveness of tactile images, these customizable boards were tested in various university classrooms as well as in participation studies which included BVI and sighted students. Results from these studies indicate that tactile images are discernable and were found to improve performance in lab exercises as much as 60% for those with visual impairment. Incorporating tactile HDPE 3D images into a classroom setting was shown to

  19. [Humans or material? Three levels of the discourse about the stem cell research from theological-ethical view].

    Science.gov (United States)

    Ernst, Stephan

    2004-01-01

    In the debate on the ethical evaluation of the stem cell research three levels can be differentiated. The first level of argumentation is that of weighing up goods: The possible therapeutical success for thousands of humans seems to justify the consumption of a few embryos. It is show, that this, however, already presupposes - on a second argumentation level - a judgement on the moral status of the embryo. Different moments of time, when human dignity and life protection are ascribe to the embryo, have already been discussed, but in spite of all rationality of the arguments a consensus has not been reached. On this third level of argumentation two fundamental meanings of reality can be differentiated. The empirical-observing and the communicative-participating view. These lead to a different moral evaluation of the embryo. This contribution votes for the priority of the communicative-participating view. It receives addition support by theology and Christian faith.

  20. Repairing rabbit radial defects by combining bone marrow stroma stem cells with bone scaffold material comprising a core-cladding structure.

    Science.gov (United States)

    Wu, H; Liu, G H; Wu, Q; Yu, B

    2015-10-05

    We prepared a bone scaffold material comprising a PLGA/β-TCP core and a Type I collagen cladding, and recombined it with bone marrow stroma stem cells (BMSCs) to evaluate its potential for use in bone tissue engineering by in vivo and in vitro experiments. PLGA/β-TCP without a cladding was used for comparison. The adherence rate of the BMSCs to the scaffold was determined by cell counting. Cell proliferation rate was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. The osteogenic capability was evaluated by alkaline phosphatase activity. The scaffold materials were recombined with the BMSCs and implanted into a large segmental rabbit radial defect model to evaluate defect repair. Osteogenesis was assessed in the scaffold materials by histological and double immunofluorescence labeling, etc. The adherence number, proliferation number, and alkaline phosphatase expression of the cells on the bone scaffold material with core-cladding structure were significantly higher than the corresponding values in the PLGA/β-TCP composite scaffold material (P structure completely degraded at the bone defect site and bone formation was completed. The rabbit large sentimental radial defect was successfully repaired. The degradation and osteogenesis rates matched well. The bone scaffold with core-cladding structure exhibited better osteogenic activity and capacity to repair a large segmental bone defect compared to the PLGA/β-TCP composite scaffold. The bone scaffold with core-cladding structure has excellent physical properties and biocompatibility. It is an ideal scaffold material for bone tissue engineering.

  1. Curcumin-functionalized silk materials for enhancing adipogenic differentiation of bone marrow-derived human mesenchymal stem cells

    Science.gov (United States)

    Li, Chunmei; Luo, Tingting; Zheng, Zhaozhu; Murphy, Amanda R.; Wang, Xiaoqin; Kaplan, David L.

    2014-01-01

    Curcumin, a natural phenolic compound derived from the plant Curcuma longa, was physically entrapped and stabilized in silk hydrogel films and its influence on human bone marrow-derived mesenchymal stem cells (hBMSCs) was assessed related to adipogenic differentiation. The presence of curcumin significantly reduced silk gelation time and changed the porous morphology of gel matrix, but did not change the formation of silk beta-sheet structure. Based on spectrofluorimetric analysis, curcumin likely interacted with hydrophobic residues in silk, interacting with the beta-sheet domains formed in the hydrogels. The antioxidant activity of silk film-associated curcumin remained functional over at least one month in both the dry and hydrated state. Negligible curcumin was released from silk hydrogel films over 48 hours incubation in aqueous solution. For hBMSCs cultured on silk films containing more than 0.25 mg/mL curcumin, cell proliferation was inhibited while adipogenesis was significantly promoted based on transcripts as well as oil red O staining. When hBMSCs were cultured in media containing free curcumin, both proliferation and adipogenesis of hBMSCs were inhibited when curcumin concentrations exceeded 5 μM, which is more than 1,000-times higher than the level of curcumin released from the films in aqueous solution. Thus, silk film-associated curcumin exhibited different effects on hBMSC proliferation and differentiation when compared to curcumin in solution. PMID:25132274

  2. The effect of perfusion culture on proliferation and differentiation of human mesenchymal stem cells on biocorrodible bone replacement material

    International Nuclear Information System (INIS)

    Farack, J.; Wolf-Brandstetter, C.; Glorius, S.; Nies, B.; Standke, G.; Quadbeck, P.; Worch, H.; Scharnweber, D.

    2011-01-01

    Biocorrodible iron foams were coated with different calcium phosphate phases (CPP) to obtain a bioactive surface and controlled degradation. Further adhesion, proliferation and differentiation of SaOs-2 and human mesenchymal stem cells were investigated under both static and dynamic culture conditions. Hydroxyapatite (HA; [Ca 10 (PO 4 ) 6 OH 2 ]) coated foams released 500 μg/g iron per day for Dulbecco's modified eagle medium (DMEM) and 250 μg/g iron per day for McCoys, the unmodified reference 1000 μg/g iron per day for DMEM and 500 μg/g iron per day for McCoys, while no corrosion could be detected on brushite (CaHPO 4 ) coated foams. Using a perfusion culture system with conditions closer to the in vivo situation, cells proliferated and differentiated on iron foams coated with either brushite or HA while in static cell culture cells could proliferate only on Fe-brushite. We conclude that the degradation behaviour of biocorrodible iron foams can be varied by different calcium phosphate coatings, offering opportunities for design of novel bone implants. Further studies will focus on the influence of different modifications of iron foams on the expression of oxidative stress enzymes. Additional information about in vivo reactions and remodelling behaviour are expected from testing in implantation studies.

  3. Artificial Niches for Stromal Stem Cells as a Potential Instrument for the Design of the Surface of Biomimetic Osteogenic Materials

    Science.gov (United States)

    Khlusov, I. A.; Khlusova, M. Yu.; Pichugin, V. F.; Sharkeev, Yu. P.; Legostaeva, E. V.

    2014-02-01

    A relationship between the topography of rough calcium phosphate surfaces having osteogenic niche-reliefs and the electrostatic potential of these surfaces as a possible instrument to control stromal stem cells has been investigated. The in vitro culture of human lung prenatal stromal cells on nanostructured/ultrafine-grained VT1.0 titanium alloy plates with bilateral rough calcium phosphate (CaP) microarc coating was used. It was established that the amplitude of the electret CaP surface potential linearly increased with increasing area of valleys (sockets), and the negative charge is formed on the socket surface. The area of alkaline phosphatase staining (the marker of osteoblast maturation and differentiation) of adherent CD34- CD44+ cells increases linearly with increasing area of artificial microterritory (socket) of the CaP surface occupied with each cell. The negative electret potential in valleys (sockets) of microarc CaP coatings can be the physical mechanism mediating the influence of the surface topography on osteogenic maturation and differentiation of cells in vitro. This mechanism can be called "niche-potential" and can be used as an instrument for biomimetic modification of smooth CaP surfaces to strengthen their integration with the bone tissue.

  4. Types of Stem Cells

    Science.gov (United States)

    ... Stem Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... Learn About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

  5. Experimental analysis of axial and radial stress distribution in soft materials used for petrochemical valve stem sealing package

    Science.gov (United States)

    Ripeanu, R. G.; Ispas, A.; Ispas, D.

    2017-02-01

    Paper presents experimental results obtained by authors regarding pressure values and distribution, by using a special pressure sensitive paper, type FujiFilm and adequate hardware equipment and a soft program FPD810 Win. Was obtained the proper axial force related for different materials in order to respect the valves sealing demands. Were showed that, pressure maps obtained depends of the construction of sealing package, density of the preformed band rings and corrected sealing replacing on location in case of square braided cord used.

  6. Dangers resulting from DNA profiling of biological materials derived from patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT with regard to forensic genetic analysis

    Directory of Open Access Journals (Sweden)

    Renata Jacewicz

    2016-07-01

    Full Text Available The study documents the risk that comes with DNA analysis of materials derived from patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT in forensic genetics. DNA chimerism was studied in 30 patients after allo-HSCT, based on techniques applied in contemporary forensic genetics, i.e. real-time PCR and multiplex PCR-STR with the use of autosomal DNA as well as Y-DNA markers. The results revealed that the DNA profile of the recipient’s blood was identical with the donor’s in the majority of cases. Therefore, blood analysis can lead to false conclusions in personal identification as well as kinship analysis. An investigation of buccal swabs revealed a mixture of DNA in the majority of recipients. Consequently, personal identification on the basis of stain analysis of the same origin may be impossible. The safest (but not ideal material turned out to be the hair root. Its analysis based on autosomal DNA revealed 100% of the recipient’s profile. However, an analysis based on Y-chromosome markers performed in female allo-HSCT recipients with male donors demonstrated the presence of donor DNA in hair cells – similarly to the blood and buccal swabs. In the light of potential risks arising from DNA profiling of biological materials derived from persons after allotransplantation in judicial aspects, certain procedures were proposed to eliminate such dangers. The basic procedures include abandoning the approach based exclusively on blood collection, both for kinship analysis and personal identification; asking persons who are to be tested about their history of allo-HSCT before sample collection and profile entry in the DNA database, and verification of DNA profiling based on hair follicles in uncertain cases.

  7. Materialism.

    Science.gov (United States)

    Melnyk, Andrew

    2012-05-01

    Materialism is nearly universally assumed by cognitive scientists. Intuitively, materialism says that a person's mental states are nothing over and above his or her material states, while dualism denies this. Philosophers have introduced concepts (e.g., realization and supervenience) to assist in formulating the theses of materialism and dualism with more precision, and distinguished among importantly different versions of each view (e.g., eliminative materialism, substance dualism, and emergentism). They have also clarified the logic of arguments that use empirical findings to support materialism. Finally, they have devised various objections to materialism, objections that therefore serve also as arguments for dualism. These objections typically center around two features of mental states that materialism has had trouble in accommodating. The first feature is intentionality, the property of representing, or being about, objects, properties, and states of affairs external to the mental states. The second feature is phenomenal consciousness, the property possessed by many mental states of there being something it is like for the subject of the mental state to be in that mental state. WIREs Cogn Sci 2012, 3:281-292. doi: 10.1002/wcs.1174 For further resources related to this article, please visit the WIREs website. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Stem cells

    NARCIS (Netherlands)

    Jukes, Jojanneke; Both, Sanne; Post, Janine; van Blitterswijk, Clemens; Karperien, Marcel; de Boer, Jan; van Blitterswijk, Clemens A.

    2008-01-01

    This chapter defines stem cells and their properties. It identifies the major differences between embryonic and adult stem cells. Stem cells can be defined by two properties: the ability to make identical copies of themselves and the ability to form other cell types of the body. These properties are

  9. Assessment of cellular materials generated by co-cultured ‘inflamed’ and healthy periodontal ligament stem cells from patient-matched groups

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Hao-Ning [State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi' an (China); Department of Stomatology, The First Affiliated Hospital of the Chinese PLA General Hospital, Beijing 100048 (China); Xia, Yu [State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi' an (China); Department of Stomatology, The 309th Hospital of Chinese People' s Liberation Army, Beijing 100091 (China); Xu, Jie; Tian, Bei-Min; Zhang, Xi-Yu [State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi' an (China); Chen, Fa-Ming, E-mail: cfmsunhh@fmmu.edu.cn [State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Periodontology, School of Stomatology, Fourth Military Medical University, Xi' an (China)

    2016-08-01

    Recently, stem cells derived from the'inflamed’ periodontal ligament (PDL) tissue of periodontally diseased teeth (I-PDLSCs) have been increasingly suggested as a more readily accessible source of cells for regenerative therapies than those derived from healthy PDL tissue (H-PDLSCs). However, substantial evidence indicates that I-PDLSCs exhibit impaired functionalities compared with H-PDLSCs. In this study, patient-matched I-PDLSCs and H-PDLSCs were co-cultured at various ratios. Cellular materials derived from these cultures were investigated regarding their osteogenic potential in vitro and capacity to form new bone following in vivo transplantation. While patient-matched I-PDLSCs and H-PDLSCs could co-exist in co-culture systems, the proportion of I-PDLSCs tended to increase during in vitro incubation. Compared with H-PDLSC monoculture, the presence of I-PDLSCs in the co-cultures appeared to enhance the overall cell proliferation. Although not completely rescued, the osteogenic and regenerative potentials of the cellular materials generated by co-cultured I-PDLSCs and H-PDLSCs were significantly improved compared with those derived from I-PDLSC monocultures. Notably, cells in co-cultures containing either 50% I-PDLSCs plus 50% H-PDLSCs or 25% I-PDLSCs plus 75% H-PDLSCs expressed osteogenesis-related proteins and genes at levels similar to those expressed in H-PDLSC monocultures (P>0.05). Irrespective of the percentage of I-PDLSCs, robust cellular materials were obtained from co-cultures with 50% or more H-PDLSCs, which exhibited equivalent potential to form new bone in vivo compared with sheets generated by H-PDLSC monocultures. These data suggest that the co-culture of I-PDLSCs with patient-matched H-PDLSCs is a practical and effective method for increasing the overall osteogenic and regenerative potentials of resultant cellular materials. - Highlights: • Co-culturing H-PDLSCs with I-PDLSCs led to rapid cell expansion. • H-PDLSCs and I-PDLSCs co

  10. Assessment of cellular materials generated by co-cultured ‘inflamed’ and healthy periodontal ligament stem cells from patient-matched groups

    International Nuclear Information System (INIS)

    Tang, Hao-Ning; Xia, Yu; Xu, Jie; Tian, Bei-Min; Zhang, Xi-Yu; Chen, Fa-Ming

    2016-01-01

    Recently, stem cells derived from the'inflamed’ periodontal ligament (PDL) tissue of periodontally diseased teeth (I-PDLSCs) have been increasingly suggested as a more readily accessible source of cells for regenerative therapies than those derived from healthy PDL tissue (H-PDLSCs). However, substantial evidence indicates that I-PDLSCs exhibit impaired functionalities compared with H-PDLSCs. In this study, patient-matched I-PDLSCs and H-PDLSCs were co-cultured at various ratios. Cellular materials derived from these cultures were investigated regarding their osteogenic potential in vitro and capacity to form new bone following in vivo transplantation. While patient-matched I-PDLSCs and H-PDLSCs could co-exist in co-culture systems, the proportion of I-PDLSCs tended to increase during in vitro incubation. Compared with H-PDLSC monoculture, the presence of I-PDLSCs in the co-cultures appeared to enhance the overall cell proliferation. Although not completely rescued, the osteogenic and regenerative potentials of the cellular materials generated by co-cultured I-PDLSCs and H-PDLSCs were significantly improved compared with those derived from I-PDLSC monocultures. Notably, cells in co-cultures containing either 50% I-PDLSCs plus 50% H-PDLSCs or 25% I-PDLSCs plus 75% H-PDLSCs expressed osteogenesis-related proteins and genes at levels similar to those expressed in H-PDLSC monocultures (P>0.05). Irrespective of the percentage of I-PDLSCs, robust cellular materials were obtained from co-cultures with 50% or more H-PDLSCs, which exhibited equivalent potential to form new bone in vivo compared with sheets generated by H-PDLSC monocultures. These data suggest that the co-culture of I-PDLSCs with patient-matched H-PDLSCs is a practical and effective method for increasing the overall osteogenic and regenerative potentials of resultant cellular materials. - Highlights: • Co-culturing H-PDLSCs with I-PDLSCs led to rapid cell expansion. • H-PDLSCs and I-PDLSCs co

  11. Hierarchically porous carbon nanosheets derived from Moringa oleifera stems as electrode material for high-performance electric double-layer capacitors

    Science.gov (United States)

    Cai, Yijin; Luo, Ying; Dong, Hanwu; Zhao, Xiao; Xiao, Yong; Liang, Yeru; Hu, Hang; Liu, Yingliang; Zheng, Mingtao

    2017-06-01

    A facile one-step pyrolysis route for the synthesis of hierarchically porous carbon nanosheets (PCNSs) derived from Moringa oleifera stems (MOSs) is reported, in which no post-activation-process in needed. The as-prepared PCNSs possesses unique porous nanosheet morphology with high specific surface area of ca. 2250 m2 g-1, large pore volume of ca. 2.3 cm3 g-1, appropriate porosity as well as heteroatom doping (N and O), endowing outstanding electrochemical properties as electrode material for high-performance supercapacitors. The PCNS-based electrodes are investigated in various aqueous electrolytes including 1.0 M Na2SO4, 1.0 M H2SO4, and 6.0 M KOH. The PCNSs exhibit a maximum specific capacitance of ca. 283 F g-1 (0.5 A g-1), excellent rate capability (ca. 72% of capacitance retention even at an ultrahigh current density of 50 A g-1), and a tremendous long-term cycling stability in the three-electrode system. Moreover, the as-assembled PCNS-based symmetric supercapacitor shows a high energy density of ca. 25.8 Wh kg-1 (in 1.0 M Na2SO4 electrolyte) and remarkable long-term cycling stability (almost no capacitance fade in aqueous electrolytes), indicating the promising of the as-prepared PCNSs for electrochemical energy storage and conversion.

  12. A multifunctional bioactive material that stimulates osteogenesis and promotes the vascularization bone marrow stem cells and their resistance to bacterial infection.

    Directory of Open Access Journals (Sweden)

    Chuang Ma

    Full Text Available The main limitation of tissue engineering lies in the inability to stimulate osteogenesis, angiogenesis of stem cells and broad-spectrum antimicrobial activity. However, the development of multifunctional bioactive materials with these capabilities remains a great challenge. In this study, we prepared mesoporous silica nanoparticles encapsulated with silver nanocrystals (AG-MSN with uniform sphere size and mesopores. Platelet-derived growth factor BB (PDGF-BB was effectively loaded in the AG-MSN mesopores (P-AG-MSN. The silicon ions (Si released by P-AG-MSN stimulate osteogenic differentiation of bone marrow stromal cells (BMSC by activating the alkaline phosphatase (ALP activity of bone-related genes and increasing protein (OCN, RUNX2 and OPN expression. Ag+ ions could be slowly released from the interior of the shell, highlighting their durable antibacterial activity. The sustained release of PDGF-BB from P-AG-MSN stimulated the angiogenic differentiation of BMSC, as indicated by the enhanced secretion of vascular endothelial growth factor (VEGF, HIF-1α, HGF and ANG-1 and protein expression. Our results show that P-AG-MSN can clearly promote BMSC osteostimulation and vascularization. This research serves as a preliminary study of the utilization of this multifunctional mixture to fabricate a new active biological scaffold that integrates BMSC osteostimulation, vascularization and bactericidal effects by 3D printing technology.

  13. Materials

    CSIR Research Space (South Africa)

    Van Wyk, Llewellyn V

    2009-02-01

    Full Text Available . It is generally included as part of a structurally insulated panel (SIP) where the foam is sandwiched between external skins of steel, wood or cement. Cement composites Cement bonded composites are an important class of building materials. These products... for their stone buildings, including the Egyptians, Aztecs and Inca’s. As stone is a very dense material it requires intensive heating to become warm. Rocks were generally stacked dry but mud, and later cement, can be used as a mortar to hold the rocks...

  14. In-vitro interactions of human chondrocytes and mesenchymal stem cells, and of mouse macrophages with phospholipid-covered metallic implant materials

    Directory of Open Access Journals (Sweden)

    R Willumeit

    2007-03-01

    Full Text Available Phospholipid-coatings on metallic implant surfaces were evaluated in terms of adhesion, proliferation and matrix production of skeletal cells, and of macrophage stimulation. The working hypothesis is that mimicking a model biomembrane by phospholipids on surfaces to which cells adhere, the surface recognition by surrounding cells is altered. In this study, 1 mirror-like polished Ti-6Al-7Nb and 2 porous Ti-6Al-4V specimens were covered with the phospholipids POPE (palmitoyl-oleoyl phosphatidyl-ethanolamine and POPC (palmitoyl-oleoyl phosphatidyl-choline, and the interactions of a human articular chondrocytes (HAC, b human mesenchymal stem cells (HMSC, and c mouse macrophages (RAW 264.7 were tested in vitro. On POPE-covered polished surfaces adherence of HAC (42% of seeded cells after 2 hrs and metabolic activity (MTT after 3 days were reduced, while on porous surfaces 99% HAC adhered, and metabolic activity was significantly increased, compared to respective native surfaces. On both POPE-covered surfaces the chondrocyte phenotype was present. After 3 weeks of chondrogenic differentiation, cartilage matrix production (measuring chondroitin sulphate per HAC number was significantly increased by about 30% on both POPE-covered metallic surfaces. On both POPC-covered surfaces nearly no adhering and surviving HAC were found. HMSC grown on POPE-covered porous substrates showed osteogenic differentiation by improved osteopontin and collagen I expression in RT-PCR, and osteocalcin fluorescence and bone nodule formation was only detectable on POPE-covered porous surfaces. In contrast to POPC and other phospholipids used as positive controls, POPE did not stimulate the NO production in mouse macrophage cultures. We therefore conclude that a phospholipid coating by POPE shows potential as surface modification for metallic implant materials.

  15. The use of embryonic stem cell derived bioactive material as a new protein supplement for the in vitro culture of bovine embryos.

    Science.gov (United States)

    Kim, Eun Young; Lee, Jun Beom; Park, Hyo Young; Jeong, Chang Jin; Riu, Key Zung; Park, Se Pill

    2011-06-01

    Embryonic stem (ES) cells are expanded versions of the inner cell mass cells that compose the early mammalian blastocyst. Components derived from ES cells may contain various bioactive materials (BM) helpful for early preimplantation embryo growth. In this study, we examined the effect of human ES cell derived BM (hES-BM) on in vitro culture of bovine embryos. When bovine parthenogenetic day 2 embryos were cultured in 10% hES-BM, a significantly higher embryo development rate (44.3%) and increased cell numbers were observed relative to control medium containing 3 mg/ml BSA (19.5%; Pculture environment to support the growth of bovine embryos in vitro (P<0.05). Little difference was observed between 10% hES-BM and 10% FBS treatment in the examined parthenogenetic or in vitro fertilized embryos, although the hES-BM group developed at a slightly better rate. However, the ICM cell numbers were significantly higher in the hES-BM group in irrespective of embryo origin (P<0.05). In addition, the relative levels of pluripotency (Oct4, × 1.8 fold; Nanog. × 3.3 fold), embryogenesis (Stat3, × 2.8 fold; FGF4, × 18.8 fold; E-cad, × 2.0 fold) and growth (Glut5, × 2.6 fold) genes were significantly higher in the 10% hES-BM group than in the 10% FBS group (P<0.05), while the levels of other genes (Bax, Bcl2, MnSOD and Connexin43) were not different. This is the first report examining the positive effects of hES-BM on bovine embryo development in vitro. Based on our results, we conclude that hES-BM can be used as a new protein supplement for bovine preimplantation embryo development.

  16. STEM Education.

    Science.gov (United States)

    Xie, Yu; Fang, Michael; Shauman, Kimberlee

    2015-08-01

    Improving science, technology, engineering, and mathematics (STEM) education, especially for traditionally disadvantaged groups, is widely recognized as pivotal to the U.S.'s long-term economic growth and security. In this article, we review and discuss current research on STEM education in the U.S., drawing on recent research in sociology and related fields. The reviewed literature shows that different social factors affect the two major components of STEM education attainment: (1) attainment of education in general, and (2) attainment of STEM education relative to non-STEM education conditional on educational attainment. Cognitive and social psychological characteristics matter for both major components, as do structural influences at the neighborhood, school, and broader cultural levels. However, while commonly used measures of socioeconomic status (SES) predict the attainment of general education, social psychological factors are more important influences on participation and achievement in STEM versus non-STEM education. Domestically, disparities by family SES, race, and gender persist in STEM education. Internationally, American students lag behind those in some countries with less economic resources. Explanations for group disparities within the U.S. and the mediocre international ranking of US student performance require more research, a task that is best accomplished through interdisciplinary approaches.

  17. Learn About Stem Cells

    Science.gov (United States)

    ... Patient Handbook Stem Cell Glossary Search Toggle Nav Stem Cell Basics Stem cells are the foundation from which ... original cell’s DNA, cytoplasm and cell membrane. About stem cells Stem cells are the foundation of development in ...

  18. STEM Education

    Science.gov (United States)

    & Development (LDRD) National Security Education Center (NSEC) Office of Science Programs Richard P Databases National Security Education Center (NSEC) Center for Nonlinear Studies Engineering Institute Scholarships STEM Education Programs Teachers (K-12) Students (K-12) Higher Education Regional Education

  19. Bone regeneration and stem cells

    Science.gov (United States)

    Arvidson, K; Abdallah, B M; Applegate, L A; Baldini, N; Cenni, E; Gomez-Barrena, E; Granchi, D; Kassem, M; Konttinen, Y T; Mustafa, K; Pioletti, D P; Sillat, T; Finne-Wistrand, A

    2011-01-01

    Abstract This invited review covers research areas of central importance for orthopaedic and maxillofacial bone tissue repair, including normal fracture healing and healing problems, biomaterial scaffolds for tissue engineering, mesenchymal and foetal stem cells, effects of sex steroids on mesenchymal stem cells, use of platelet-rich plasma for tissue repair, osteogenesis and its molecular markers. A variety of cells in addition to stem cells, as well as advances in materials science to meet specific requirements for bone and soft tissue regeneration by addition of bioactive molecules, are discussed. PMID:21129153

  20. Bone regeneration and stem cells

    DEFF Research Database (Denmark)

    Arvidson, K; Abdallah, B M; Applegate, L A

    2011-01-01

    cells, use of platelet rich plasma for tissue repair, osteogenesis and its molecular markers. A variety of cells in addition to stem cells, as well as advances in materials science to meet specific requirements for bone and soft tissue regeneration by addition of bioactive molecules, are discussed.......This invited review covers research areas of central importance for orthopedic and maxillofacial bone tissue repair, including normal fracture healing and healing problems, biomaterial scaffolds for tissue engineering, mesenchymal and fetal stem cells, effects of sex steroids on mesenchymal stem...

  1. Stem Cell Basics

    Science.gov (United States)

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... Basics » Stem Cell Basics I. Back to top Stem Cell Basics I. Introduction: What are stem cells, and ...

  2. Stem Cells

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2004-01-01

    In his influential essay on markets, An essay on framing and overflowing (1998), Michel Callon writes that `the growing complexity of industrialized societies [is] due in large part to the movements of the technosciences, which are causing connections and interdependencies to proliferate'. This p...... and tantalizing than stem cells, in research, in medicine, or as products.......'. This paper is about tech-noscience, and about the proliferation of connections and interdependencies created by it.More specifically, the paper is about stem cells. Biotechnology in general has the power to capture the imagination. Within the field of biotechnology nothing seems more provocative...

  3. Why STEM?

    Science.gov (United States)

    Mitts, Charles R.

    2016-01-01

    The International Technology and Engineering Educators Association (ITEEA) defines STEM as a new transdisciplinary subject in schools that integrates the disciplines of science, technology, engineering, and mathematics into a single course of study. There are three major problems with this definition: There is no consensus in support of the ITEEA…

  4. Fast Atomic-Scale Elemental Mapping of Crystalline Materials by STEM Energy-Dispersive X-Ray Spectroscopy Achieved with Thin Specimens.

    Science.gov (United States)

    Lu, Ping; Yuan, Renliang; Zuo, Jian Min

    2017-02-01

    Elemental mapping at the atomic-scale by scanning transmission electron microscopy (STEM) using energy-dispersive X-ray spectroscopy (EDS) provides a powerful real-space approach to chemical characterization of crystal structures. However, applications of this powerful technique have been limited by inefficient X-ray emission and collection, which require long acquisition times. Recently, using a lattice-vector translation method, we have shown that rapid atomic-scale elemental mapping using STEM-EDS can be achieved. This method provides atomic-scale elemental maps averaged over crystal areas of ~few 10 nm2 with the acquisition time of ~2 s or less. Here we report the details of this method, and, in particular, investigate the experimental conditions necessary for achieving it. It shows, that in addition to usual conditions required for atomic-scale imaging, a thin specimen is essential for the technique to be successful. Phenomenological modeling shows that the localization of X-ray signals to atomic columns is a key reason. The effect of specimen thickness on the signal delocalization is studied by multislice image simulations. The results show that the X-ray localization can be achieved by choosing a thin specimen, and the thickness of less than about 22 nm is preferred for SrTiO3 in [001] projection for 200 keV electrons.

  5. Stem cell biobanks.

    Science.gov (United States)

    Bardelli, Silvana

    2010-04-01

    Stem cells contribute to innate healing and harbor a promising role for regenerative medicine. Stem cell banking through long-term storage of different stem cell platforms represents a fundamental source to preserve original features of stem cells for patient-specific clinical applications. Stem cell research and clinical translation constitute fundamental and indivisible modules catalyzed through biobanking activity, generating a return of investment.

  6. Stem cell tourism and public education: the missing elements.

    Science.gov (United States)

    Master, Zubin; Robertson, Kelsey; Frederick, Daniel; Rachul, Christen; Caulfield, Timothy

    2014-09-04

    Stem cell tourism describes the Internet-based industry where in patients receive unproven stem cell interventions. To better inform the public, several organizations provide educational material on stem cell therapies and tourism; however, an assessment of the currently available resources reveals a lack of comprehensive information, suggesting that further efforts are needed. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Nurse’s A-Phase Material Enhance Adhesion, Growth and Differentiation of Human Bone Marrow-Derived Stromal Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Ruben Rabadan-Ros

    2017-03-01

    Full Text Available The purpose of this study was to evaluate the bioactivity and cell response of a well-characterized Nurse’s A-phase (7CaO·P2O5·2SiO2 ceramic and its effect compared to a control (tissue culture polystyrene-TCPS on the adhesion, viability, proliferation, and osteogenic differentiation of ahMSCs in vitro. Cell proliferation (Alamar Blue Assay, Alizarin Red-S (AR-s staining, alkaline phosphatase (ALP activity, osteocalcin (OCN, and collagen I (Col I were evaluated. Also, field emission scanning electron microscopy (FESEM images were acquired in order to visualise the cells and the topography of the material. The proliferation of cells growing in a direct contact with the material was slower at early stages of the study because of the new environmental conditions. However, the entire surface was colonized after 28 days of culture in growth medium (GM. Osteoblastic differentiation markers were significantly enhanced in cells growing on Nurse’s A phase ceramic and cultured with osteogenic medium (OM, probably due to the role of silica to stimulate the differentiation of ahMSCs. Moreover, calcium nodules were formed under the influence of ceramic material. Therefore, it is predicted that Nurse’s A-phase ceramic would present high biocompatibility and osteoinductive properties and would be a good candidate to be used as a biomaterial for bone tissue engineering.

  8. Engaging STEM Ethics Education

    Directory of Open Access Journals (Sweden)

    Kelly Ann Joyce

    2018-03-01

    Full Text Available The automation of knowledge via algorithms, code and big data has brought new ethical concerns that computer scientists and engineers are not yet trained to identify or mediate. We present our experience of using original research to develop scenarios to explore how STS scholars can produce materials that facilitate ethics education in computer science, data science, and software engineering. STS scholars are uniquely trained to investigate the societal context of science and technology as well as the meaning STEM researchers attach to their day-to-day work practices. In this project, we use a collaborative, co-constitutive method of doing ethics education that focuses on building an ethical framework based on empirical practices, highlighting two issues in particular: data validity and the relations between data and inequalities. Through data-grounded scenario writing, we demonstrate how STS scholars and other social scientists can apply their expertise to the production of educational materials to spark broad ranging discussions that explore the connections between values, ethics, STEM, politics, and social contexts.

  9. Biomaterial-stem cell interactions and their impact on stem cell response

    NARCIS (Netherlands)

    Oziemlak-Schaap, Aneta M.; Kuhn, Philipp T.; van Kooten, Theo G.; van Rijn, Patrick

    2014-01-01

    In this review, current research in the field of biomaterial properties for directing stem cells are discussed and placed in a critical perspective. Regenerative medicine, in which stem cells play a crucial role, has become an interdisciplinary field between cell biology and materials science. New

  10. Stem cell-based approaches in dentistry

    Directory of Open Access Journals (Sweden)

    TA Mitsiadis

    2011-11-01

    Full Text Available Repair of dental pulp and periodontal lesions remains a major clinical challenge. Classical dental treatments require the use of specialised tissue-adapted materials with still questionable efficacy and durability. Stem cell-based therapeutic approaches could offer an attractive alternative in dentistry since they can promise physiologically improved structural and functional outcomes. These therapies necessitate a sufficient number of specific stem cell populations for implantation. Dental mesenchymal stem cells can be easily isolated and are amenable to in vitro expansion while retaining their stemness. In vivo studies realised in small and large animals have evidenced the potential of dental mesenchymal stem cells to promote pulp and periodontal regeneration, but have also underlined new important challenges. The homogeneity of stem cell populations and their quality control, the delivery method, the quality of the regenerated dental tissues and their integration to the host tissue are some of the key challenges. The use of bioactive scaffolds that can elicit effective tissue repair response, through activation and mobilisation of endogenous stem cell populations, constitutes another emerging therapeutic strategy. Finally, the use of stem cells and induced pluripotent cells for the regeneration of entire teeth represents a novel promising alternative to dental implant treatment after tooth loss. In this mini-review, we present the currently applied techniques in restorative dentistry and the various attempts that are made to bridge gaps in knowledge regarding treatment strategies by translating basic stem cell research into the dental practice.

  11. Potency of Stem Cells

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Potency of Stem Cells. Totipotent Stem Cells (Zygote + first 2 divisions). -Can form placenta, embryo, and any cell of the body. Pluripotent (Embryonic Stem Cells). -Can form any cell of the body but can not form placenta, hence no embryo. Multipotent (Adult stem cells).

  12. What's missing? Discussing stem cell translational research in educational information on stem cell "tourism".

    Science.gov (United States)

    Master, Zubin; Zarzeczny, Amy; Rachul, Christen; Caulfield, Timothy

    2013-01-01

    Stem cell tourism is a growing industry in which patients pursue unproven stem cell therapies for a wide variety of illnesses and conditions. It is a challenging market to regulate due to a number of factors including its international, online, direct-to-consumer approach. Calls to provide education and information to patients, their families, physicians, and the general public about the risks associated with stem cell tourism are mounting. Initial studies examining the perceptions of patients who have pursued stem cell tourism indicate many are highly critical of the research and regulatory systems in their home countries and believe them to be stagnant and unresponsive to patient needs. We suggest that educational material should include an explanation of the translational research process, in addition to other aspects of stem cell tourism, as one means to help promote greater understanding and, ideally, curb patient demand for unproven stem cell interventions. The material provided must stress that strong scientific research is required in order for therapies to be safe and have a greater chance at being effective. Through an analysis of educational material on stem cell tourism and translational stem cell research from patient groups and scientific societies, we describe essential elements that should be conveyed in educational material provided to patients. Although we support the broad dissemination of educational material on stem cell translational research, we also acknowledge that education may simply not be enough to engender patient and public trust in domestic research and regulatory systems. However, promoting patient autonomy by providing good quality information to patients so they can make better informed decisions is valuable in itself, irrespective of whether it serves as an effective deterrent of stem cell tourism. © 2013 American Society of Law, Medicine & Ethics, Inc.

  13. Mesenchymal stem cell-mediated functional tooth regeneration in swine.

    Directory of Open Access Journals (Sweden)

    Wataru Sonoyama

    2006-12-01

    Full Text Available Mesenchymal stem cell-mediated tissue regeneration is a promising approach for regenerative medicine for a wide range of applications. Here we report a new population of stem cells isolated from the root apical papilla of human teeth (SCAP, stem cells from apical papilla. Using a minipig model, we transplanted both human SCAP and periodontal ligament stem cells (PDLSCs to generate a root/periodontal complex capable of supporting a porcelain crown, resulting in normal tooth function. This work integrates a stem cell-mediated tissue regeneration strategy, engineered materials for structure, and current dental crown technologies. This hybridized tissue engineering approach led to recovery of tooth strength and appearance.

  14. Tumourigenicity and radiation resistance of mesenchymal stem cells

    DEFF Research Database (Denmark)

    D'Andrea, Filippo Peder; Horsman, Michael Robert; Kassem, Moustapha

    2012-01-01

    Background. Cancer stem cells are believed to be more radiation resistant than differentiated tumour cells of the same origin. It is not known, however, whether normal nontransformed adult stem cells share the same radioresistance as their cancerous counterpart. Material and methods....... Nontumourigenic (TERT4) and tumourigenic (TRET20) cell lines, from an immortalised mesenchymal stem cell line, were grown in culture prior to irradiation and gene expression analysis. Radiation resistance was measured using a clonogenic assay. Differences in gene expression between the two cell lines, both under...... the intercellular matrix. These results also indicate that cancer stem cells are more radiation resistant than stem cells of the same origin....

  15. Stem Cell Transplant

    Science.gov (United States)

    ... Graft-versus-host disease: A potential risk when stem cells come from donors If you receive a transplant ... medications and blood products into your body. Collecting stem cells for transplant If a transplant using your own ...

  16. Stem Cell Information: Glossary

    Science.gov (United States)

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... here Home » Glossary Back to top Glossary Adult stem cell Astrocyte Blastocoel Blastocyst Bone marrow stromal cells Bone ...

  17. Plant stem cell niches.

    Science.gov (United States)

    Stahl, Yvonne; Simon, Rüdiger

    2005-01-01

    Stem cells are required to support the indeterminate growth style of plants. Meristems are a plants stem cell niches that foster stem cell survival and the production of descendants destined for differentiation. In shoot meristems, stem cell fate is decided at the populational level. The size of the stem cell domain at the meristem tip depends on signals that are exchanged with cells of the organizing centre underneath. In root meristems, individual stem cells are controlled by direct interaction with cells of the quiescent centre that lie in the immediate neighbourhood. Analysis of the interactions and signaling processes in the stem cell niches has delivered some insights into the molecules that are involved and revealed that the two major niches for plant stem cells are more similar than anticipated.

  18. Does Applied STEM Course Taking Link to STEM Outcomes for High School Students With Learning Disabilities?

    Science.gov (United States)

    Gottfried, Michael A; Sublett, Cameron

    Over the most recent two decades, federal policy has urged high schools to embed applied science, technology, engineering, and mathematics (STEM) courses into the curriculum to reinforce concepts learned in traditional math and science classes as well as to motivate students' interests and long-term pursuits in STEM areas. While prior research has examined whether these courses link to STEM persistence for the general student population, no work has examined the role of these courses for students with learning disabilities (LDs). This is a critical lapse, as these courses have been supported as being one path by which STEM material can become more accessible for students with diverse learning needs. Hence, this descriptive study examines the landscape of applied STEM course taking for students with LDs. The findings suggest students with LDs are less likely to take applied STEM courses in high school compared to the general population. Additionally, while the general population does benefit from taking these courses, there is a unique association between applied STEM course taking and advanced math and science course taking or math achievement for students with LDs. Hence, there is no evidence that applied STEM course taking is related to any closure of the STEM achievement gap for students with LDs.

  19. Nano scaffolds and stem cell therapy in liver tissue engineering

    Science.gov (United States)

    Montaser, Laila M.; Fawzy, Sherin M.

    2015-08-01

    Tissue engineering and regenerative medicine have been constantly developing of late due to the major progress in cell and organ transplantation, as well as advances in materials science and engineering. Although stem cells hold great potential for the treatment of many injuries and degenerative diseases, several obstacles must be overcome before their therapeutic application can be realized. These include the development of advanced techniques to understand and control functions of micro environmental signals and novel methods to track and guide transplanted stem cells. A major complication encountered with stem cell therapies has been the failure of injected cells to engraft to target tissues. The application of nanotechnology to stem cell biology would be able to address those challenges. Combinations of stem cell therapy and nanotechnology in tissue engineering and regenerative medicine have achieved significant advances. These combinations allow nanotechnology to engineer scaffolds with various features to control stem cell fate decisions. Fabrication of Nano fiber cell scaffolds onto which stem cells can adhere and spread, forming a niche-like microenvironment which can guide stem cells to proceed to heal damaged tissues. In this paper, current and emergent approach based on stem cells in the field of liver tissue engineering is presented for specific application. The combination of stem cells and tissue engineering opens new perspectives in tissue regeneration for stem cell therapy because of the potential to control stem cell behavior with the physical and chemical characteristics of the engineered scaffold environment.

  20. Creative Teaching in STEM

    Science.gov (United States)

    Pollard, Vikki; Hains-Wesson, Rachael; Young, Karen

    2018-01-01

    If Science, Technology, Engineering and Mathematics (STEM) disciplines in higher education are to retain students, there needs to be a shift towards teaching in more enriching and interesting ways. Creative teaching needs to become more prominent in STEM. This article presents a study that defines creative teaching in the STEM context and…

  1. Engineering Hydrogel Microenvironments to Recapitulate the Stem Cell Niche.

    Science.gov (United States)

    Madl, Christopher M; Heilshorn, Sarah C

    2018-06-04

    Stem cells are a powerful resource for many applications including regenerative medicine, patient-specific disease modeling, and toxicology screening. However, eliciting the desired behavior from stem cells, such as expansion in a naïve state or differentiation into a particular mature lineage, remains challenging. Drawing inspiration from the native stem cell niche, hydrogel platforms have been developed to regulate stem cell fate by controlling microenvironmental parameters including matrix mechanics, degradability, cell-adhesive ligand presentation, local microstructure, and cell-cell interactions. We survey techniques for modulating hydrogel properties and review the effects of microenvironmental parameters on maintaining stemness and controlling differentiation for a variety of stem cell types. Looking forward, we envision future hydrogel designs spanning a spectrum of complexity, ranging from simple, fully defined materials for industrial expansion of stem cells to complex, biomimetic systems for organotypic cell culture models.

  2. Telomere stability and telomerase in mesenchymal stem cells

    DEFF Research Database (Denmark)

    Serakinci, Nedime; Graakjaer, Jesper; Kølvrå, Steen

    2008-01-01

    Telomeres are repetitive genetic material that cap and thereby protect the ends of chromosomes. Each time a cell divides, telomeres get shorter. Telomere length is mainly maintained by telomerase. This enzyme is present in high concentrations in the embryonic stem cells and in fast growing...... embryonic cells, and declines with age. It is still unclear to what extent there is telomerase in adult stem cells, but since these are the founder cells of cells of all the tissues in the body, understanding the telomere dynamics and expression of telomerase in adult stem cells is very important....... In the present communication we focus on telomere expression and telomere length in stem cells, with a special focus on mesenchymal stem cells. We consider different mechanisms by which stem cells can maintain telomeres and also focus on the dynamics of telomere length in mesenchymal stem cells, both the overall...

  3. Plant stem cell niches.

    Science.gov (United States)

    Aichinger, Ernst; Kornet, Noortje; Friedrich, Thomas; Laux, Thomas

    2012-01-01

    Multicellular organisms possess pluripotent stem cells to form new organs, replenish the daily loss of cells, or regenerate organs after injury. Stem cells are maintained in specific environments, the stem cell niches, that provide signals to block differentiation. In plants, stem cell niches are situated in the shoot, root, and vascular meristems-self-perpetuating units of organ formation. Plants' lifelong activity-which, as in the case of trees, can extend over more than a thousand years-requires that a robust regulatory network keep the balance between pluripotent stem cells and differentiating descendants. In this review, we focus on current models in plant stem cell research elaborated during the past two decades, mainly in the model plant Arabidopsis thaliana. We address the roles of mobile signals on transcriptional modules involved in balancing cell fates. In addition, we discuss shared features of and differences between the distinct stem cell niches of Arabidopsis.

  4. Stem Cell Pathology.

    Science.gov (United States)

    Fu, Dah-Jiun; Miller, Andrew D; Southard, Teresa L; Flesken-Nikitin, Andrea; Ellenson, Lora H; Nikitin, Alexander Yu

    2018-01-24

    Rapid advances in stem cell biology and regenerative medicine have opened new opportunities for better understanding disease pathogenesis and the development of new diagnostic, prognostic, and treatment approaches. Many stem cell niches are well defined anatomically, thereby allowing their routine pathological evaluation during disease initiation and progression. Evaluation of the consequences of genetic manipulations in stem cells and investigation of the roles of stem cells in regenerative medicine and pathogenesis of various diseases such as cancer require significant expertise in pathology for accurate interpretation of novel findings. Therefore, there is an urgent need for developing stem cell pathology as a discipline to facilitate stem cell research and regenerative medicine. This review provides examples of anatomically defined niches suitable for evaluation by diagnostic pathologists, describes neoplastic lesions associated with them, and discusses further directions of stem cell pathology.

  5. Sensing radiosensitivity of human epidermal stem cells

    International Nuclear Information System (INIS)

    Rachidi, Walid; Harfourche, Ghida; Lemaitre, Gilles; Amiot, Franck; Vaigot, Pierre; Martin, Michele T.

    2007-01-01

    Purpose: Radiosensitivity of stem cells is a matter of debate. For mouse somatic stem cells, both radiosensitive and radioresistant stem cells have been described. By contrast, the response of human stem cells to radiation has been poorly studied. As epidermis is a radiosensitive tissue, we evaluated in the present work the radiosensitivity of cell populations enriched for epithelial stem cells of human epidermis. Methods and materials: The total keratinocyte population was enzymatically isolated from normal human skin. We used flow cytometry and antibodies against cell surface markers to isolate basal cell populations from human foreskin. Cell survival was measured after a dose of 2 Gy with the XTT assay at 72 h after exposure and with a clonogenic assay at 2 weeks. Transcriptome analysis using oligonucleotide microarrays was performed to assess the genomic cell responses to radiation. Results: Cell sorting based on two membrane proteins, α6 integrin and the transferrin receptor CD71, allowed isolation of keratinocyte populations enriched for the two types of cells found in the basal layer of epidermis: stem cells and progenitors. Both the XTT assay and the clonogenic assay showed that the stem cells were radioresistant whereas the progenitors were radiosensitive. We made the hypothesis that upstream DNA damage signalling might be different in the stem cells and used microarray technology to test this hypothesis. The stem cells exhibited a much more reduced gene response to a dose of 2 Gy than the progenitors, as we found that 6% of the spotted genes were regulated in the stem cells and 20% in the progenitors. Using Ingenuity Pathway Analysis software, we found that radiation exposure induced very specific pathways in the stem cells. The most striking responses were the repression of a network of genes involved in apoptosis and the induction of a network of cytokines and growth factors. Conclusion: These results show for the first time that keratinocyte

  6. Stem cell therapy. Use of differentiated pluripotent stem cells as replacement therapy for treating disease

    DEFF Research Database (Denmark)

    Fox, Ira J; Daley, George Q; Goldman, Steven A

    2014-01-01

    Pluripotent stem cells (PSCs) directed to various cell fates holds promise as source material for treating numerous disorders. The availability of precisely differentiated PSC-derived cells will dramatically affect blood component and hematopoietic stem cell therapies and should facilitate......, and industry is critical for generating new stem cell-based therapies....... treatment of diabetes, some forms of liver disease and neurologic disorders, retinal diseases, and possibly heart disease. Although an unlimited supply of specific cell types is needed, other barriers must be overcome. This review of the state of cell therapies highlights important challenges. Successful...

  7. ¬Mesenchymal Stem Cell Fate: Applying Biomaterials for Control of Stem Cell Behaviour

    Directory of Open Access Journals (Sweden)

    Hilary Jane Anderson

    2016-05-01

    Full Text Available Mesenchymal Stem Cell Fate: Applying Biomaterials for Control of Stem Cell BehaviourHilary J Anderson1, Jugal Kishore Sahoo2, Rein V Ulijn2,3, Matthew J Dalby1*1 Centre for Cell Engineering, University of Glasgow, Glasgow, UK.2 Technology and Innovation centre, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, UK. 3 Advanced Science Research Centre (ASRC and Hunter College, City University of New York, NY 10031, NY, USA. Correspondence:*Hilary Andersonh.anderson.1@research.gla.ac.ukKeywords: mesenchymal stem cells, bioengineering, materials synthesis, nanotopography, stimuli responsive material□AbstractThe materials pipeline for biomaterials and tissue engineering applications is under continuous development. Specifically, there is great interest in the use of designed materials in the stem cell arena as materials can be used to manipulate the cells providing control of behaviour. This is important as the ability to ‘engineer’ complexity and subsequent in vitro growth of tissues and organs is a key objective for tissue engineers. This review will describe the nature of the materials strategies, both static and dynamic, and their influence specifically on mesenchymal stem cell fate.

  8. Global Collaborative STEM Education

    Science.gov (United States)

    Meabh Kelly, Susan; Smith, Walter

    2016-04-01

    Global Collaborative STEM Education, as the name suggests, simultaneously supports two sets of knowledge and skills. The first set is STEM -- science, technology, engineering and math. The other set of content knowledge and skills is that of global collaboration. Successful global partnerships require awareness of one's own culture, the biases embedded within that culture, as well as developing awareness of the collaborators' culture. Workforce skills fostered include open-mindedness, perseverance when faced with obstacles, and resourceful use of technological "bridges" to facilitate and sustain communication. In respect for the 2016 GIFT Workshop focus, Global Collaborative STEM Education projects dedicated to astronomy research will be presented. The projects represent different benchmarks within the Global Collaborative STEM Education continuum, culminating in an astronomy research experience that fully reflects how the global STEM workforce collaborates. To facilitate wider engagement in Global Collaborative STEM Education, project summaries, classroom resources and contact information for established international collaborative astronomy research projects will be disseminated.

  9. Dental pulp stem cells

    DEFF Research Database (Denmark)

    Ashri, N. Y.; Ajlan, S. A.; Aldahmash, Abdullah M.

    2015-01-01

    scaffold, and guided through signaling molecules. Dental pulp stem cells have been used in an increasing number of studies in dental tissue engineering. Those cells show mesenchymal (stromal) stem cell-like properties including self-renewal and multilineage differentiation potentials, aside from...... an updated review on dental pulp stem cells and their applications in periodontal regeneration, in combination with different scaffolds and growth factors....

  10. Integrative STEM Education Defined

    OpenAIRE

    Sanders, Mark E.

    2015-01-01

    “My work with integrative STEM education began in 1990 with the NSF-funded Technology, Science, Mathematics Integration Project… By 2008, I was convinced “STEM Education” was (and always would be) a hopelessly ambiguous phrase, and therefore felt we absolutely needed to rename our “STEM Education” graduate program and develop a tight operational definition of the central idea underlying our program, in hopes of preventing the sort of hopeless ambiguity that ruined the term “STEM education” fr...

  11. Stem Cells and Aging.

    Science.gov (United States)

    Koliakos, George

    2017-02-01

    The article is a presentation at the 4th Conference of ESAAM, which took place on October 30-31, 2015, in Athens, Greece. Its purpose was not to cover all aspects of cellular aging but to share with the audience of the Conference, in a 15-minute presentation, current knowledge about the rejuvenating and repairing somatic stem cells that are distinct from other stem cell types (such as embryonic or induced pluripotent stem cells), emphasize that our body in old age cannot take advantage of these rejuvenating cells, and provide some examples of novel experimental stem cell applications in the field of rejuvenation and antiaging biomedical research.

  12. Science Fiction Exhibits as STEM Gateways

    Science.gov (United States)

    Robie, Samantha

    Women continue to hold less than a quarter of all STEM jobs in the United States, prompting many museums to develop programs and exhibits with the express goal of interesting young girls in scientific fields. At the same time, a number of recent museum exhibits have harnessed the popularity of pop culture and science fiction in order to interest general audiences in STEM subject matter, as well as using the exhibits as springboards to expand or shift mission goals and focus. Because science fiction appears to be successful at raising interest in STEM fields, it may be an effective way to garner the interest of young girls in STEM in particular. This research seeks to describe the ways in which museums are currently using science fiction exhibits to interest young girls in STEM fields and careers. Research focused on four institutions across the country hosting three separate exhibits, and included staff interviews and content analysis of exhibit descriptions, promotional materials, a summative evaluation and supplementary exhibit productions. In some ways, science fiction exhibits do serve young girls, primarily through the inclusion of female role models, staff awareness, and prototype testing to ensure interactives are attractive to girls as well as to boys. However, STEM appears to be underutilized, which may be partly due to a concern within the field that the outcome of targeting a specific gender could be construed as "stereotyping".

  13. The stem factor challenge

    International Nuclear Information System (INIS)

    Russell, M.J.; Steele, R. Jr.; DeWall, K.G.; Watkins, J.C.; Bramwell, D.

    1994-01-01

    One of the most important challenges that still needs to be met in the effort to understand the operation of motor-operated, rising-stem valves is the ability to determine stem factor throughout the valve's load range. The stem factor represents the conversion of operator torque to stem thrust. Determining the stem factor is important because some motor-operated valves (MOVs) cannot be tested in the plant at design basis conditions. The ability of these valves to perform their design basis function (typically, to operate against specified flow and pressure loads) must be ensured by analytical methods or by extrapolating from the results of tests conducted at lower loads. Because the stem factor tends to vary in response to friction and lubrication phenomena that occur during loading and wedging, analytical methods and extrapolation methods have been difficult to develop and implement. Early investigations into variability in the stem factor tended to look only at the tip of the iceberg; they focused on what was happening at torque switch trip, which usually occurs at full wedging. In most stems, the stem factor is better (lower) in the wedging transient than before wedging, so working with torque switch trip data alone led many early researchers to false conclusions about the relationship between stem factor and load. However, research at the Idaho National Engineering Laboratory (INEL) has taken a closer look at what happens during the running portion of the closing stroke along with the wedging portion. This shift in focus is important, because functional failure of a valve typically consists of a failure to isolate flow, not a failure to achieve full wedging. Thus, the stem factor that must be determined for a valve's design basis closing requirements is the one that corresponds with the running load before wedging

  14. Donating Peripheral Blood Stem Cells

    Science.gov (United States)

    ... Print this page My Cart Donating peripheral blood stem cells Peripheral blood stem cell (PBSC) donation is a nonsurgical procedure to collect ... Donating bone marrow Donor experiences videos Peripheral blood stem cell (PBSC) donation is one of two methods of ...

  15. Stem Cell Transplants (For Teens)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Stem Cell Transplants KidsHealth / For Teens / Stem Cell Transplants What's ... Take to Recover? Coping Print What Are Stem Cells? As you probably remember from biology class, every ...

  16. Graphene for enhanced embryonic stem cell photo-transfection efficiency

    CSIR Research Space (South Africa)

    Mthunzi, P

    2013-04-01

    Full Text Available Due to their pluripotency properties, embryonic stem (ES) cells possess great potential in regenerative therapy. Since reported a promising tissue engineering scaffold material, here, graphene is demonstrated to significantly improve the ES cell...

  17. Comparison of chemotherapy and hematopoietic stem cell ...

    African Journals Online (AJOL)

    2013-02-19

    Feb 19, 2013 ... scores before and after hematopoietic stem cell transplantation (HSCT) and chemotherapy. Materials and Methods: Thirty-six patients undergoing HSCT were included in the study. A pre-HSCT dental treatment protocol was implemented that consisted of restoration of all active carious lesions, treatment of ...

  18. SYNERGISTIC ANTIBACTERIAL EFFECT OF STEM BARK ...

    African Journals Online (AJOL)

    userpc

    ABSTRACT. The study was aimed at screening the stem bark extracts of Faidherbia albida and Psidium guajava for synergistic antibacterial effect against methicillin resistant Staphylococcus aureus (MRSA). The powdered plant materials were extracted with methanol using cold maceration technique and the extracts were ...

  19. Solving the problem of valve stem leakage

    International Nuclear Information System (INIS)

    Dixon, D.F.

    1976-01-01

    Engineering solutions to valve stem leakage, in systems carrying expensive heavy water under pressure, have progressed from changing packing brands (failure) to leak collection (partial success) to elimination of small packed valves and an improved valve packing strategy involving stable packing materials, live Belleville spring-loading of packing, and issuance of a detailed stuffing box specification (success). (E.C.B.)

  20. Colorectal cancer stem cells.

    Science.gov (United States)

    Salama, Paul; Platell, Cameron

    2009-10-01

    Somatic stem cells reside at the base of the crypts throughout the colonic mucosa. These cells are essential for the normal regeneration of the colonic epithelium. The stem cells reside within a special 'niche' comprised of intestinal sub-epithelial myofibroblasts that tightly control their function. It has been postulated that mutations within these adult colonic stem cells may induce neoplastic changes. Such cells can then dissociate from the epithelium and travel into the mesenchyme and thus form invasive cancers. This theory is based on the observation that within a colon cancer, less than 1% of the neoplastic cells have the ability to regenerate the tumour. It is this group of cells that exhibits characteristics of colonic stem cells. Although anti-neoplastic agents can induce remissions by inhibiting cell division, the stem cells appear to be remarkably resistant to both standard chemotherapy and radiotherapy. These stem cells may therefore persist after treatment and form the nucleus for cancer recurrence. Hence, future treatment modalities should focus specifically on controlling the cancer stem cells. In this review, we discuss the biology of normal and malignant colonic stem cells.

  1. Aneuploidy in stem cells

    NARCIS (Netherlands)

    Garcia-Martinez, Jorge; Bakker, Bjorn; Schukken, Klaske M; Simon, Judith E; Foijer, Floris

    2016-01-01

    Stem cells hold enormous promise for regenerative medicine as well as for engineering of model systems to study diseases and develop new drugs. The discovery of protocols that allow for generating induced pluripotent stem cells (IPSCs) from somatic cells has brought this promise steps closer to

  2. Dazlin' pluripotent stem cells

    NARCIS (Netherlands)

    Welling, M.A.

    2014-01-01

    Pluripotent embryonic stem cells (ESCs) can be isolated from the inner cell mass (ICM) of blastocyst embryos and differentiate into all three germ layers in vitro. However, despite their similar origin, mouse embryonic stem cells represent a more naïve ICM-like pluripotent state whereas human

  3. Cancer stem cells revisited

    NARCIS (Netherlands)

    Batlle, Eduard; Clevers, Hans

    2017-01-01

    The cancer stem cell (CSC) concept was proposed four decades ago, and states that tumor growth, analogous to the renewal of healthy tissues, is fueled by small numbers of dedicated stem cells. It has gradually become clear that many tumors harbor CSCs in dedicated niches, and yet their

  4. The Hidden STEM Economy

    Science.gov (United States)

    Rothwell, Jonathan

    2013-01-01

    Workers in STEM (science, technology, engineering, and math) fields play a direct role in driving economic growth. Yet, because of how the STEM economy has been defined, policymakers have mainly focused on supporting workers with at least a bachelor's (BA) degree, overlooking a strong potential workforce of those with less than a BA. This report…

  5. Disruptive innovation, labor markets, and Big Valley STEM School: network analysis in STEM education

    Science.gov (United States)

    Ellison, Scott; Allen, Ben

    2018-03-01

    A defining characteristic of contemporary trends in global education policy is the promotion of STEM learning in the primary, secondary, and tertiary sectors of education as a means to generate innovation and prosperity in the economy. Intertwined with common sensical assumptions about future labor markets and the transformative potential of technology in education, STEM has become a hegemonic discourse informing policy formation and educational practice. In Gramscian terms, the struggle over STEM as a discursive practice, between proponents of instrumental learning of marketable economic skills and those of education towards humanistic goals, reveals insights about the ideological characteristics of the push for STEM learning. This article explores the power dynamics behind the push for STEM learning as an ideological discourse propagated by global networks of elite policy actors and enacted by non-elite policy actors at the school level. The findings point toward a disjuncture between the discourse of elite policy actors in the US, the realities of STEM labor markets, and the actualization of this policy discourse into classroom practice. The implications of this study indicate that analyses of vertical power relations in network governance in STEM education should attend to the semiotics, materiality, and mutability of networked spaces.

  6. Propagation of human spermatogonial stem cells in vitro.

    Science.gov (United States)

    Sadri-Ardekani, Hooman; Mizrak, Sefika C; van Daalen, Saskia K M; Korver, Cindy M; Roepers-Gajadien, Hermien L; Koruji, Morteza; Hovingh, Suzanne; de Reijke, Theo M; de la Rosette, Jean J M C H; van der Veen, Fulco; de Rooij, Dirk G; Repping, Sjoerd; van Pelt, Ans M M

    2009-11-18

    Young boys treated with high-dose chemotherapy are often confronted with infertility once they reach adulthood. Cryopreserving testicular tissue before chemotherapy and autotransplantation of spermatogonial stem cells at a later stage could theoretically allow for restoration of fertility. To establish in vitro propagation of human spermatogonial stem cells from small testicular biopsies to obtain an adequate number of cells for successful transplantation. Study performed from April 2007 to July 2009 using testis material donated by 6 adult men who underwent orchidectomy as part of prostate cancer treatment. Testicular cells were isolated and cultured in supplemented StemPro medium; germline stem cell clusters that arose were subcultured on human placental laminin-coated dishes in the same medium. Presence of spermatogonia was determined by reverse transcriptase polymerase chain reaction and immunofluorescence for spermatogonial markers. To test for the presence of functional spermatogonial stem cells in culture, xenotransplantation to testes of immunodeficient mice was performed, and migrated human spermatogonial stem cells after transplantation were detected by COT-1 fluorescence in situ hybridization. The number of colonized spermatogonial stem cells transplanted at early and later points during culture were counted to determine propagation. Propagation of spermatogonial stem cells over time. Testicular cells could be cultured and propagated up to 15 weeks. Germline stem cell clusters arose in the testicular cell cultures from all 6 men and could be subcultured and propagated up to 28 weeks. Expression of spermatogonial markers on both the RNA and protein level was maintained throughout the entire culture period. In 4 of 6 men, xenotransplantation to mice demonstrated the presence of functional spermatogonial stem cells, even after prolonged in vitro culture. Spermatogonial stem cell numbers increased 53-fold within 19 days in the testicular cell culture and

  7. What is a stem cell?

    Science.gov (United States)

    Slack, Jonathan M W

    2018-05-15

    The historical roots of the stem cell concept are traced with respect to its usage in embryology and in hematology. The modern consensus definition of stem cells, comprising both pluripotent stem cells in culture and tissue-specific stem cells in vivo, is explained and explored. Methods for identifying stem cells are discussed with respect to cell surface markers, telomerase, label retention and transplantability, and properties of the stem cell niche are explored. The CreER method for identifying stem cells in vivo is explained, as is evidence in favor of a stochastic rather than an obligate asymmetric form of cell division. In conclusion, it is found that stem cells do not possess any unique and specific molecular markers; and stem cell behavior depends on the environment of the cell as well as the stem cell's intrinsic qualities. Furthermore, the stochastic mode of division implies that stem cell behavior is a property of a cell population not of an individual cell. In this sense, stem cells do not exist in isolation but only as a part of multicellular system. This article is categorized under: Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches Adult Stem Cells, Tissue Renewal, and Regeneration > Methods and Principles Adult Stem Cells, Tissue Renewal, and Regeneration > Environmental Control of Stem Cells. © 2018 Wiley Periodicals, Inc.

  8. Chromatin in embryonic stem cell neuronal differentiation.

    Science.gov (United States)

    Meshorer, E

    2007-03-01

    Chromatin, the basic regulatory unit of the eukaryotic genetic material, is controlled by epigenetic mechanisms including histone modifications, histone variants, DNA methylation and chromatin remodeling. Cellular differentiation involves large changes in gene expression concomitant with alterations in genome organization and chromatin structure. Such changes are particularly evident in self-renewing pluripotent embryonic stem cells, which begin, in terms of cell fate, as a tabula rasa, and through the process of differentiation, acquire distinct identities. Here I describe the changes in chromatin that accompany neuronal differentiation, particularly of embryonic stem cells, and discuss how chromatin serves as the master regulator of cellular destiny.

  9. Allowable stem nut wear and diagnostic monitoring for MOVs

    International Nuclear Information System (INIS)

    Swinburne, P.

    1994-01-01

    After a motor-operated valve (MOV) stem nut failure in 1991 that contributed to a forced plant shutdown, the FitzPatrick Plant staff developed criteria to check for excessive stem nut wear in MOVs. Allowable stem nut wear monitoring uses both direct dimensional measurement and diagnostic test data interpretation. The wear allowance is based on the recommended permitted backlash discussed in the Electric Power Research Institute/Nuclear Maintenance Assistance Center Technical Repair Guideline for the Limitorque SMB-000 Motor Actuator. The diagnostic analysis technique measures the time at zero load and compares this with a precalculated allowable zero force time. Excessive zero force time may be the result of other MOV problems, such as a loose stem nut lock nut or excessive free play in the drive sleeve bearing. Stress levels for new or nominal stem nuts and stem nuts with the full wear allowance were compared. Bending and shear stresses at the thread root increase for the maximum wear condition when compared with a open-quotes newclose quotes stem nut. These stresses are directly related to the thread root thickness. For typical MOV loading and common stem threading (with two diameters of thread engagement), the thread stresses are well within acceptable limits for ASTM B584-C86300 (formerly B147-863) manganese bronze (typical stem nut material)

  10. Leaf and stem morphoanatomy of Petiveria alliacea.

    Science.gov (United States)

    Duarte, M R; Lopes, J F

    2005-12-01

    Petiveria alliacea is a perennial herb native to the Amazonian region and used in traditional medicine for different purposes, such as diuretic, antispasmodic and anti-inflammatory. The morphoanatomical characterization of the leaf and stem was carried out, in order to contribute to the medicinal plant identification. The plant material was fixed, freehand sectioned and stained either with toluidine blue or astra blue and basic fuchsine. Microchemical tests were also applied. The leaf is simple, alternate and elliptic. The blade exhibits paracytic stomata on the abaxial side, non-glandular trichomes and dorsiventral mesophyll. The midrib is biconvex and the petiole is plain-convex, both traversed by collateral vascular bundles adjoined with sclerenchymatic caps. The stem, in incipient secondary growth, presents epidermis, angular collenchyma, starch sheath and collateral vascular organization. Several prisms of calcium oxalate are seen in the leaf and stem.

  11. Stemming options and their effect on containment

    International Nuclear Information System (INIS)

    Day, J.A.

    1976-01-01

    In more than 17 years of studying underground nuclear explosions, LLL has developed containment procedures that include a stemming plan. Stemming plans can be divided into either layered or continuous forms. There are marked differences between standards for these forms. The materials used in the continuous plan must meet more stringent specifications; as a consequence, they are more expensive. Both plans have been successful since the Baneberry Event. Both plans must meet the following requirements: provide a plug sufficient to match the overburden density of earth; contain radioactive gases at the lowest possible depth; minimize the generation of noncondensable gases (such as CO 2 ); minimize gas flow rates during the early post-detonation stages when cavity pressure is high; and be compatible with the experiment and its diagnostics. LLL experience in developing containment procedures is reviewed, and the reasons for the adoption of LLL's continuous stemming plan are reported

  12. On the quantitativeness of EDS STEM

    Energy Technology Data Exchange (ETDEWEB)

    Lugg, N.R. [Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); Kothleitner, G. [Institute for Electron Microscopy and Nanoanalysis, Graz University of Technology, Steyrergasse 17, 8010 Graz (Austria); Centre for Electron Microscopy, Steyrergasse 17, 8010 Graz (Austria); Shibata, N.; Ikuhara, Y. [Institute of Engineering Innovation, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2015-04-15

    Chemical mapping using energy dispersive X-ray spectroscopy (EDS) in scanning transmission electron microscopy (STEM) has recently shown to be a powerful technique in analyzing the elemental identity and location of atomic columns in materials at atomic resolution. However, most applications of EDS STEM have been used only to qualitatively map whether elements are present at specific sites. Obtaining calibrated EDS STEM maps so that they are on an absolute scale is a difficult task and even if one achieves this, extracting quantitative information about the specimen – such as the number or density of atoms under the probe – adds yet another layer of complexity to the analysis due to the multiple elastic and inelastic scattering of the electron probe. Quantitative information may be obtained by comparing calibrated EDS STEM with theoretical simulations, but in this case a model of the structure must be assumed a priori. Here we first theoretically explore how exactly elastic and thermal scattering of the probe confounds the quantitative information one is able to extract about the specimen from an EDS STEM map. We then show using simulation how tilting the specimen (or incident probe) can reduce the effects of scattering and how it can provide quantitative information about the specimen. We then discuss drawbacks of this method – such as the loss of atomic resolution along the tilt direction – but follow this with a possible remedy: precession averaged EDS STEM mapping. - Highlights: • Signal obtained in EDS STEM maps (of STO) compared to non-channelling signal. • Deviation from non-channelling signal occurs in on-axis experiments. • Tilting specimen: signal close to non-channelling case but atomic resolution is lost. • Tilt-precession series: non-channelling signal and atomic-resolution features obtained. • Associated issues are discussed.

  13. Innovation and STEM Schools

    Science.gov (United States)

    Roberts, Julia Link

    2015-01-01

    How do schools with a focus on science, technology, engineering, and mathematics (STEM) fit in with state goals to increase innovation and to boost the economy? This article briefly discusses how educators can encourage creativity and innovation.

  14. [STEM on Station Education

    Science.gov (United States)

    Lundebjerg, Kristen

    2016-01-01

    The STEM on Station team is part of Education which is part of the External Relations organization (ERO). ERO has traditional goals based around BHAG (Big Hairy Audacious Goal). The BHAG model is simplified to a saying: Everything we do stimulates actions by others to advance human space exploration. The STEM on Station education initiate is a project focused on bringing off the earth research and learning into classrooms. Educational resources such as lesson plans, activities to connect with the space station and STEM related contests are available and hosted by the STEM on Station team along with their partners such as Texas Instruments. These educational activities engage teachers and students in the current happenings aboard the international space station, inspiring the next generation of space explorers.

  15. STEM Education Programs

    Science.gov (United States)

    & Development (LDRD) National Security Education Center (NSEC) Office of Science Programs Richard P Databases National Security Education Center (NSEC) Center for Nonlinear Studies Engineering Institute Scholarships STEM Education Programs Teachers (K-12) Students (K-12) Higher Education Regional Education

  16. Human stem cells for craniomaxillofacial reconstruction.

    Science.gov (United States)

    Jalali, Morteza; Kirkpatrick, William Niall Alexander; Cameron, Malcolm Gregor; Pauklin, Siim; Vallier, Ludovic

    2014-07-01

    Human stem cell research represents an exceptional opportunity for regenerative medicine and the surgical reconstruction of the craniomaxillofacial complex. The correct architecture and function of the vastly diverse tissues of this important anatomical region are critical for life supportive processes, the delivery of senses, social interaction, and aesthetics. Craniomaxillofacial tissue loss is commonly associated with inflammatory responses of the surrounding tissue, significant scarring, disfigurement, and psychological sequelae as an inevitable consequence. The in vitro production of fully functional cells for skin, muscle, cartilage, bone, and neurovascular tissue formation from human stem cells, may one day provide novel materials for the reconstructive surgeon operating on patients with both hard and soft tissue deficit due to cancer, congenital disease, or trauma. However, the clinical translation of human stem cell technology, including the application of human pluripotent stem cells (hPSCs) in novel regenerative therapies, faces several hurdles that must be solved to permit safe and effective use in patients. The basic biology of hPSCs remains to be fully elucidated and concerns of tumorigenicity need to be addressed, prior to the development of cell transplantation treatments. Furthermore, functional comparison of in vitro generated tissue to their in vivo counterparts will be necessary for confirmation of maturity and suitability for application in reconstructive surgery. Here, we provide an overview of human stem cells in disease modeling, drug screening, and therapeutics, while also discussing the application of regenerative medicine for craniomaxillofacial tissue deficit and surgical reconstruction.

  17. Myeloproliferative neoplasm stem cells.

    Science.gov (United States)

    Mead, Adam J; Mullally, Ann

    2017-03-23

    Myeloproliferative neoplasms (MPNs) arise in the hematopoietic stem cell (HSC) compartment as a result of the acquisition of somatic mutations in a single HSC that provides a selective advantage to mutant HSC over normal HSC and promotes myeloid differentiation to engender a myeloproliferative phenotype. This population of somatically mutated HSC, which initiates and sustains MPNs, is termed MPN stem cells. In >95% of cases, mutations that drive the development of an MPN phenotype occur in a mutually exclusive manner in 1 of 3 genes: JAK2 , CALR , or MPL The thrombopoietin receptor, MPL, is the key cytokine receptor in MPN development, and these mutations all activate MPL-JAK-STAT signaling in MPN stem cells. Despite common biological features, MPNs display diverse disease phenotypes as a result of both constitutional and acquired factors that influence MPN stem cells, and likely also as a result of heterogeneity in the HSC in which MPN-initiating mutations arise. As the MPN clone expands, it exerts cell-extrinsic effects on components of the bone marrow niche that can favor the survival and expansion of MPN stem cells over normal HSC, further sustaining and driving malignant hematopoiesis. Although developed as targeted therapies for MPNs, current JAK2 inhibitors do not preferentially target MPN stem cells, and as a result, rarely induce molecular remissions in MPN patients. As the understanding of the molecular mechanisms underlying the clonal dominance of MPN stem cells advances, this will help facilitate the development of therapies that preferentially target MPN stem cells over normal HSC. © 2017 by The American Society of Hematology.

  18. Skeletal (stromal) stem cells

    DEFF Research Database (Denmark)

    Abdallah, Basem M; Kermani, Abbas Jafari; Zaher, Walid

    2015-01-01

    Skeletal (marrow stromal) stem cells (BMSCs) are a group of multipotent cells that reside in the bone marrow stroma and can differentiate into osteoblasts, chondrocytes and adipocytes. Studying signaling pathways that regulate BMSC differentiation into osteoblastic cells is a strategy....../preadipocyte factor 1 (Dlk1/Pref-1), the Wnt co-receptor Lrp5 and intracellular kinases. This article is part of a Special Issue entitled: Stem Cells and Bone....

  19. Scientists' perspectives on the ethical issues of stem cell research.

    Science.gov (United States)

    Longstaff, Holly; Schuppli, Catherine A; Preto, Nina; Lafrenière, Darquise; McDonald, Michael

    2009-06-01

    This paper describes findings from an ethics education project funded by the Canadian Stem Cell Network (SCN). The project is part of a larger research initiative entitled "The Stem Cell Research Environment: Drawing the Evidence and Experience Together". The ethics education study began with a series of focus groups with SCN researchers and trainees as part of a "needs assessment" effort. The purpose of these discussions was to identify the main ethical issues associated with stem cell (SC) research from the perspective of the stem cell community. This paper will focus on five prominent themes that emerged from the focus group data including: (1) the source of stem cells; (2) the power of stem cells; (3) working within a charged research environment; (4) the regulatory context; and (5) ethics training for scientists. Additional discussions are planned with others involved in Canadian stem cell research (e.g., research ethics board members, policy makers) to supplement initial findings. These assessment results combined with existing bioethics literature will ultimately inform a web-based ethics education module for the SCN. We believe that our efforts are important for those analyzing the ethical, legal, and social issues (ELSI) in this area because our in depth understanding of stem cell researcher perspectives will enable us to develop more relevant and effective education material, which in turn should help SC researchers address the important ethical challenges in their area.

  20. Advancing Stem Cell Biology toward Stem Cell Therapeutics

    OpenAIRE

    Scadden, David; Srivastava, Alok

    2012-01-01

    Here, the International Society for Stem Cell Research (ISSCR) Clinical Translation Committee introduces a series of articles outlining the current status, opportunities, and challenges surrounding the clinical translation of stem cell therapeutics for specific medical conditions.

  1. Stem cell plasticity.

    Science.gov (United States)

    Lakshmipathy, Uma; Verfaillie, Catherine

    2005-01-01

    The central dogma in stem cell biology has been that cells isolated from a particular tissue can renew and differentiate into lineages of the tissue it resides in. Several studies have challenged this idea by demonstrating that tissue specific cell have considerable plasticity and can cross-lineage restriction boundary and give rise to cell types of other lineages. However, the lack of a clear definition for plasticity has led to confusion with several reports failing to demonstrate that a single cell can indeed differentiate into multiple lineages at significant levels. Further, differences between results obtained in different labs has cast doubt on some results and several studies still await independent confirmation. In this review, we critically evaluate studies that report stem cell plasticity using three rigid criteria to define stem cell plasticity; differentiation of a single cell into multiple cell lineages, functionality of differentiated cells in vitro and in vivo, robust and persistent engraft of transplanted cells.

  2. Mesenchymal Stem Cells

    DEFF Research Database (Denmark)

    Horwood, Nicole J.; Dazzi, Francesco; Zaher, Walid

    2012-01-01

    Mesenchymal stem cells (MSC) are stem cell populations present among the bone marrow stroma and a number of other tissues that are capable of multi-lineage differentiation into mesoderm-type cells such as osteoblasts, adipocytes and chondrocytes. MSC provide supportive stroma for growth...... and differentiation of hematopoietic stem cells (HSC) and hematopoiesis. These cells have been described as important immunoregulators due to their ability to suppress T cells proliferation. MSC can also directly contribute to tissue repair by migrating to sites of injury and providing a source of cells...... for differentiation and/or providing bystander support for resident stromal cells. This chapter discusses the cellular and molecular properties of MSC, the mechanisms by which they can modulate immune responses and the clinical applications of MSC in disorders such as graft-versus-host disease and aplastic anaemia...

  3. Stem Properties of Autobacteria

    Directory of Open Access Journals (Sweden)

    Boris A. Berdichevskyy

    2014-03-01

    Full Text Available This paper discusses the stem properties of the autobacteria as part of the activation syndrome and persistence of the endogenous microflora in the adaptation process of the macroorganism to stress, as well as the ability of the bacteria to stimulate the cells of the macroorganism to manifest stem properties. The essence of this syndrome involves testing the tissue with the autobacteria of their "host" body to identify the foci of cellular insolvency with the subsequent inclusion of the autostrains in the implementation phase of the catabolic and anabolic inflammations. Considering the genetic tropism of the microbes to the organ-specific tissue of the area affected, the existence of the stem properties of the autobacteria is assumed to be realized in the process of reparative regeneration. The great clinical significance of further study of this phenomenon is not excluded.

  4. Mammary gland stem cells

    DEFF Research Database (Denmark)

    Fridriksdottir, Agla J R; Petersen, Ole W; Rønnov-Jessen, Lone

    2011-01-01

    Distinct subsets of cells, including cells with stem cell-like properties, have been proposed to exist in normal human breast epithelium and breast carcinomas. The cellular origins of epithelial cells contributing to gland development, tissue homeostasis and cancer are, however, still poorly...... and differences between mouse and human gland development with particular emphasis on the identity and localization of stem cells, and the influence of the surrounding microenvironment. It is concluded that while recent advances in the field have contributed immense insight into how the normal mammary gland...... develops and is maintained, significant discrepancies exist between the mouse and human gland which should be taken into consideration in current and future models of mammary stem cell biology....

  5. International Society for Stem Cell Research

    Science.gov (United States)

    ... renowned stem cell and regenerative medicine community. More stem cell research Take a closer look Recent Blogs View ... story independent nonprofit organization & the voice of the stem cell research community The International Society for Stem Cell ...

  6. Composition of Mineral Produced by Dental Mesenchymal Stem Cells.

    Science.gov (United States)

    Volponi, A A; Gentleman, E; Fatscher, R; Pang, Y W Y; Gentleman, M M; Sharpe, P T

    2015-11-01

    Mesenchymal stem cells isolated from different dental tissues have been described to have osteogenic/odontogenic-like differentiation capacity, but little attention has been paid to the biochemical composition of the material that each produces. Here, we used Raman spectroscopy to analyze the mineralized materials produced in vitro by different dental cell populations, and we compared them with the biochemical composition of native dental tissues. We show that different dental stem cell populations produce materials that differ in their mineral and matrix composition and that these differ from those of native dental tissues. In vitro, BCMP (bone chip mass population), SCAP (stem cells from apical papilla), and SHED (stem cells from human-exfoliated deciduous teeth) cells produce a more highly mineralized matrix when compared with that produced by PDL (periodontal ligament), DPA (dental pulp adult), and GF (gingival fibroblast) cells. Principal component analyses of Raman spectra further demonstrated that the crystallinity and carbonate substitution environments in the material produced by each cell type varied, with DPA cells, for example, producing a more carbonate-substituted mineral and with SCAP, SHED, and GF cells creating a less crystalline material when compared with other dental stem cells and native tissues. These variations in mineral composition reveal intrinsic differences in the various cell populations, which may in turn affect their specific clinical applications. © International & American Associations for Dental Research 2015.

  7. Human mesenchymal stem cells

    DEFF Research Database (Denmark)

    Abdallah, Basem; Kassem, Moustapha

    2008-01-01

    Mesenchymal stem cells (MSC) are a group of clonogenic cells present among the bone marrow stroma and capable of multilineage differentiation into mesoderm-type cells such as osteoblasts, adipocytes and chondrocytes. Due to their ease of isolation and their differentiation potential, MSC are being...... introduced into clinical medicine in variety of applications and through different ways of administration. Here, we discuss approaches for isolation, characterization and directing differentiation of human mesenchymal stem cells (hMSC). An update of the current clinical use of the cells is also provided....

  8. Brain stem cavernous angioma

    International Nuclear Information System (INIS)

    Delcarpio-O'Donovan, R.; Melanson, D.; Tampieri, D.; Ethier, R.

    1988-01-01

    Twenty-two cases of cavernous angioma of the brain stem were definitely diagnosed by means of magnetic resonance (MR) imaging. In many cases, the diagnosis had remained elusive for several years. Clinically, some cases behaved like multiple sclerosis or brain stem tumor. Others, usually associated with bleeding, caused increased intracranial pressure or subarachnoid hemorrhage. The diagnostic limitations of computed tomography in the posterior fossa are well known. Angiography fails to reveal abnormalities, since this malformation has neither a feeding artery nor a draining vein. Diagnosticians' familiarity with the MR appearance of this lesion may save patients from invasive diagnostic studies and potentially risky treatment

  9. Biomechanics of stem cells

    Science.gov (United States)

    Spector, A. A.; Yuan, D.; Somers, S.; Grayson, W. L.

    2018-04-01

    Stem cells play a key role in the healthy development and maintenance of organisms. They are also critically important in medical treatments of various diseases. It has been recently demonstrated that the mechanical factors such as forces, adhesion, stiffness, relaxation, etc. have significant effects on stem cell functions. Under physiological conditions, cells (stem cells) in muscles, heart, and blood vessels are under the action of externally applied strains. We consider the stem cell microenvironment and performance associated with their conversion (differentiation) into skeletal muscle cells. Two problems are studied by using mathematical models whose parameters are then optimized by fitting experiments. First, we present our analysis of the process of stem cell differentiation under the application of cyclic unidirectional strain. This process is interpreted as a transition through several (six) stages where each of them is defined in terms of expression of a set of factors typical to skeletal muscle cells. The stem cell evolution toward muscle cells is described by a system of nonlinear ODEs. The parameters of the model are determined by fitting the experimental data on the time course of expression of the factors under consideration. Second, we analyse the mechanical (relaxation) properties of a scaffold that serves as the microenvironment for stem cells differentiation into skeletal muscle cells. This scaffold (surrounded by a liquid solution) is composed of unidirectional fibers with pores between them. The relaxation properties of the scaffold are studied in an experiment where a long cylindrical specimen is loaded by the application of ramp displacement until the strain reaches a prescribed value. The magnitude of the corresponding load is recorded. The specimen is considered as transversely isotropic poroelastic cylinder whose force relaxation is associated with liquid diffusion through the pores. An analytical solution for the total force applied to

  10. Incorporation of Biomaterials in Multicellular Aggregates Modulates Pluripotent Stem Cell Differentiation

    Science.gov (United States)

    Bratt-Leal, Andrés M.; Carpenedo, Richard L.; Ungrin, Mark; Zandstra, Peter W.; McDevitt, Todd C.

    2010-01-01

    Biomaterials are increasingly being used to engineer the biochemical and biophysical properties of the extracellular stem cell microenvironment in order to tailor niche characteristics and direct cell phenotype. To date, stem cell-biomaterial interactions have largely been studied by introducing stem cells into artificial environments, such as 2D cell culture on biomaterial surfaces, encapsulation of cell suspensions within hydrogel materials, or cell seeding on 3D polymeric scaffolds. In this study, microparticles fabricated from different materials, such as agarose, PLGA and gelatin, were stably integrated, in a dose-dependent manner, within aggregates of pluripotent stem cells (PSCs) prior to differentiation as a means to directly examine stem cell-biomaterial interactions in 3D. Interestingly, the presence of the materials within the stem cell aggregates differentially modulated the gene and protein expression patterns of several differentiation markers without adversely affecting cell viability. Microparticle incorporation within 3D stem cell aggregates can control the spatial presentation of extracellular environmental cues (i.e. soluble factors, extracellular matrix and intercellular adhesion molecules) as a means to direct the differentiation of stem cells for tissue engineering and regenerative medicine applications. In addition, these results suggest that the physical presence of microparticles within stem cell aggregates does not compromise PSC differentiation, but in fact the choice of biomaterials can impact the propensity of stem cells to adopt particular differentiated cell phenotypes. PMID:20864164

  11. [Progress in epidermal stem cells].

    Science.gov (United States)

    Wang, Li-Juan; Wang, You-Liang; Yang, Xiao

    2010-03-01

    Mammalian skin epidermis contains different epidermal stem cell pools which contribute to the homeostasis and repair of skin epithelium. Epidermal stem cells possess two essential features common to all stem cells: self-renewal and differentiation. Disturbing the balance between self-renewal and differentiation of epidermal stem cell often causes tumors or other skin diseases. Epidermal stem cell niches provide a special microenvironment that maintains a balance of stem cell quiescence and activity. This review primarily concentrates on the following points of the epidermal stem cells: the existing evidences, the self-renewal and differentiation, the division pattern, the signal pathways regulating self-renewal and differentiation, and the microenvironment (niche) and macroenvironment maintaining the homeostasis of stem cells.

  12. Stem cell therapy for diabetes

    Directory of Open Access Journals (Sweden)

    K O Lee

    2012-01-01

    Full Text Available Stem cell therapy holds immense promise for the treatment of patients with diabetes mellitus. Research on the ability of human embryonic stem cells to differentiate into islet cells has defined the developmental stages and transcription factors involved in this process. However, the clinical applications of human embryonic stem cells are limited by ethical concerns, as well as the potential for teratoma formation. As a consequence, alternative forms of stem cell therapies, such as induced pluripotent stem cells, umbilical cord stem cells and bone marrow-derived mesenchymal stem cells, have become an area of intense study. Recent advances in stem cell therapy may turn this into a realistic treatment for diabetes in the near future.

  13. Engineering stem cell niches in bioreactors

    OpenAIRE

    Liu, Meimei; Liu, Ning; Zang, Ru; Li, Yan; Yang, Shang-Tian

    2013-01-01

    Stem cells, including embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells and amniotic fluid stem cells have the potential to be expanded and differentiated into various cell types in the body. Efficient differentiation of stem cells with the desired tissue-specific function is critical for stem cell-based cell therapy, tissue engineering, drug discovery and disease modeling. Bioreactors provide a great platform to regulate the stem cell microenvironment, known as “ni...

  14. Receptor control in mesenchymal stem cell engineering

    Science.gov (United States)

    Dalby, Matthew J.; García, Andrés J.; Salmeron-Sanchez, Manuel

    2018-03-01

    Materials science offers a powerful tool to control mesenchymal stem cell (MSC) growth and differentiation into functional phenotypes. A complex interplay between the extracellular matrix and growth factors guides MSC phenotypes in vivo. In this Review, we discuss materials-based bioengineering approaches to direct MSC fate in vitro and in vivo, mimicking cell-matrix-growth factor crosstalk. We first scrutinize MSC-matrix interactions and how the properties of a material can be tailored to support MSC growth and differentiation in vitro, with an emphasis on MSC self-renewal mechanisms. We then highlight important growth factor signalling pathways and investigate various materials-based strategies for growth factor presentation and delivery. Integrin-growth factor crosstalk in the context of MSC engineering is introduced, and bioinspired material designs with the potential to control the MSC niche phenotype are considered. Finally, we summarize important milestones on the road to MSC engineering for regenerative medicine.

  15. Looking into the Future: Toward Advanced 3D Biomaterials for Stem-Cell-Based Regenerative Medicine.

    Science.gov (United States)

    Liu, Zhongmin; Tang, Mingliang; Zhao, Jinping; Chai, Renjie; Kang, Jiuhong

    2018-04-01

    Stem-cell-based therapies have the potential to provide novel solutions for the treatment of a variety of diseases, but the main obstacles to such therapies lie in the uncontrolled differentiation and functional engraftment of implanted tissues. The physicochemical microenvironment controls the self-renewal and differentiation of stem cells, and the key step in mimicking the stem cell microenvironment is to construct a more physiologically relevant 3D culture system. Material-based 3D assemblies of stem cells facilitate the cellular interactions that promote morphogenesis and tissue organization in a similar manner to that which occurs during embryogenesis. Both natural and artificial materials can be used to create 3D scaffolds, and synthetic organic and inorganic porous materials are the two main kinds of artificial materials. Nanotechnology provides new opportunities to design novel advanced materials with special physicochemical properties for 3D stem cell culture and transplantation. Herein, the advances and advantages of 3D scaffold materials, especially with respect to stem-cell-based therapies, are first outlined. Second, the stem cell biology in 3D scaffold materials is reviewed. Third, the progress and basic principles of developing 3D scaffold materials for clinical applications in tissue engineering and regenerative medicine are reviewed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Information on Stem Cell Research

    Science.gov (United States)

    ... Home » Current Research » Focus on Research Focus on Stem Cell Research Stem cells possess the unique ability to differentiate into ... virus infection. To search the complete list of stem cell research projects funded by NIH please go to NIH ...

  17. Stem Cells in Burn Eschar

    NARCIS (Netherlands)

    van der Veen, V. C.; Vlig, M.; van Milligen-Kummer, F.J.; de Vries, S.I.; Middelkoop, E.; Ulrich, M.

    2012-01-01

    This study compares mesenchymal cells isolated from excised burn wound eschar with adipose-derived stem cells (ASCs) and dermal fibroblasts in their ability to conform to the requirements for multipotent mesenchymal stem cells (MSCs). A population of multipotent stem cells in burn eschar could be an

  18. Stem cell organization in Arabidopsis

    NARCIS (Netherlands)

    Wendrich, J.R.

    2016-01-01

    Growth of plant tissues and organs depends on continuous production of new cells, by niches of stem cells. Stem cells typically divide to give rise to one differentiating daughter and one non-differentiating daughter. This constant process of self-renewal ensures that the niches of stem cells or

  19. Fake news portrayals of stem cells and stem cell research.

    Science.gov (United States)

    Marcon, Alessandro R; Murdoch, Blake; Caulfield, Timothy

    2017-10-01

    This study examines how stem cells and stem cell research are portrayed on websites deemed to be purveyors of distorted and dubious information. Content analysis was conducted on 224 articles from 2015 to 2016, compiled by searching with the keywords 'stem cell(s)' on a list of websites flagged for containing either 'fake' or 'junk science' news. Articles contained various exaggerated positive and negative claims about stem cells and stem cell science, health and science related conspiracy theories, and statements promoting fear and mistrust of conventional medicine. Findings demonstrate the existence of organized misinformation networks, which may lead the public away from accurate information and facilitate a polarization of public discourse.

  20. Preliminary pharmacognostic screening of Achyranthes coynei stem

    Directory of Open Access Journals (Sweden)

    Vinayak Upadhya

    2015-01-01

    Full Text Available Achyranthes coynei is a rare, endemic perennial shrub reported from Karnataka and Maharashtra states of India. The plant is used to treat various disorders by folk healers and was proven to have antimicrobial and antioxidant properties. The present study was undertaken to evaluate microscopic and macroscopic characters of A. coynei stem, along with its physicochemical parameters. ProgRes ® CapturePro and Microsoft Excel were used for statistical analysis. Perennial, shrubby nature and woody stem were the distinguishing morphological characters observed. Transverse section (TS illustrated quadrangular outline of the stem and showed the presence of two types of trichomes on the thick-walled epidermis. TS also showed number of rosette calcium oxalates crystals; prismatic and microsphenoid crystals; conjoint, collateral open secondary vascular bundles; and two amphixylic medullary bundles in the pith. Ash and extractive values, micro and macro elements and nutritive factors were estimated in the present study. The presence of alkaloids, saponins and triterpenoids were observed in preliminary phytochemical screening. High-performance thin layer chromatographic analysis yielded different bands and also indicated the presence of oleanolic acid. The studied parameters for A. coynei stem will be useful for identification and authentication of the plant material.

  1. Preliminary pharmacognostic screening of Achyranthes coynei stem.

    Science.gov (United States)

    Upadhya, Vinayak; Ankad, Gireesh M; Pai, Sandeep R; Hegde, Shruti V; Hegde, Harsha V

    2015-01-01

    Achyranthes coynei is a rare, endemic perennial shrub reported from Karnataka and Maharashtra states of India. The plant is used to treat various disorders by folk healers and was proven to have antimicrobial and antioxidant properties. The present study was undertaken to evaluate microscopic and macroscopic characters of A. coynei stem, along with its physicochemical parameters. ProgRes(®) CapturePro and Microsoft Excel were used for statistical analysis. Perennial, shrubby nature and woody stem were the distinguishing morphological characters observed. Transverse section (TS) illustrated quadrangular outline of the stem and showed the presence of two types of trichomes on the thick-walled epidermis. TS also showed number of rosette calcium oxalates crystals; prismatic and microsphenoid crystals; conjoint, collateral open secondary vascular bundles; and two amphixylic medullary bundles in the pith. Ash and extractive values, micro and macro elements and nutritive factors were estimated in the present study. The presence of alkaloids, saponins and triterpenoids were observed in preliminary phytochemical screening. High-performance thin layer chromatographic analysis yielded different bands and also indicated the presence of oleanolic acid. The studied parameters for A. coynei stem will be useful for identification and authentication of the plant material.

  2. STEM learning activity among home-educating families

    Science.gov (United States)

    Bachman, Jennifer

    2011-12-01

    Science, technology, engineering, and mathematics (STEM) learning was studied among families in a group of home-educators in the Pacific Northwest. Ethnographic methods recorded learning activity (video, audio, fieldnotes, and artifacts) which was analyzed using a unique combination of Cultural-Historical Activity Theory (CHAT) and Mediated Action (MA), enabling analysis of activity at multiple levels. Findings indicate that STEM learning activity is family-led, guided by parents' values and goals for learning, and negotiated with children to account for learner interests and differences, and available resources. Families' STEM education practice is dynamic, evolves, and influenced by larger societal STEM learning activity. Parents actively seek support and resources for STEM learning within their home-school community, working individually and collectively to share their funds of knowledge. Home-schoolers also access a wide variety of free-choice learning resources: web-based materials, museums, libraries, and community education opportunities (e.g. afterschool, weekend and summer programs, science clubs and classes, etc.). A lesson-heuristic, grounded in Mediated Action, represents and analyzes home STEM learning activity in terms of tensions between parental goals, roles, and lesson structure. One tension observed was between 'academic' goals or school-like activity and 'lifelong' goals or everyday learning activity. Theoretical and experiential learning was found in both activity, though parents with academic goals tended to focus more on theoretical learning and those with lifelong learning goals tended to be more experiential. Examples of the National Research Council's science learning strands (NRC, 2009) were observed in the STEM practices of all these families. Findings contribute to the small but growing body of empirical CHAT research in science education, specifically to the empirical base of family STEM learning practices at home. It also fills a

  3. "Excellence" in STEM Education

    Science.gov (United States)

    Clark, Aaron C.

    2012-01-01

    So what does it take to achieve excellence in STEM education? That is the title of the author's presentation delivered at International Technology and Engineering Educators Association's (ITEEA's) FTEE "Spirit of Excellence" Breakfast on March 16, 2012, in Long Beach, California. In preparation for this presentation, the author went back and read…

  4. Stem cell heterogeneity revealed

    DEFF Research Database (Denmark)

    Andersen, Marianne S; Jensen, Kim B

    2016-01-01

    The skin forms a protective, water-impermeable barrier consisting of heavily crosslinked epithelial cells. However, the specific role of stem cells in sustaining this barrier remains a contentious issue. A detailed analysis of the interfollicular epidermis now proposes a model for how a composite...... of cells with different properties are involved in its maintenance....

  5. Paraneoplastic brain stem encephalitis.

    Science.gov (United States)

    Blaes, Franz

    2013-04-01

    Paraneoplastic brain stem encephalitis can occur as an isolated clinical syndrome or, more often, may be part of a more widespread encephalitis. Different antineuronal autoantibodies, such as anti-Hu, anti-Ri, and anti-Ma2 can be associated with the syndrome, and the most frequent tumors are lung and testicular cancer. Anti-Hu-associated brain stem encephalitis does not normally respond to immunotherapy; the syndrome may stabilize under tumor treatment. Brain stem encephalitis with anti-Ma2 often improves after immunotherapy and/or tumor therapy, whereas only a minority of anti-Ri positive patients respond to immunosuppressants or tumor treatment. The Opsoclonus-myoclonus syndrome (OMS) in children, almost exclusively associated with neuroblastoma, shows a good response to steroids, ACTH, and rituximab, some patients do respond to intravenous immunoglobulins or cyclophosphamide. In adults, OMS is mainly associated with small cell lung cancer or gynecological tumors and only a small part of the patients show improvement after immunotherapy. Earlier diagnosis and treatment seem to be one major problem to improve the prognosis of both, paraneoplastic brain stem encephalitis, and OMS.

  6. stem bark in rodents

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-02

    May 2, 2008 ... The effect of the extract on the normal intestinal transit in mice was not significant. However, in the ... kunthianum stem bark was therefore investigated in mice and rats' in vivo ..... sons, London, 11: 544. Izzo AA, Nicoletti M, ...

  7. Porcine embryonic stem cells

    DEFF Research Database (Denmark)

    Hall, Vanessa Jane

    2008-01-01

    The development of porcine embryonic stem cell lines (pESC) has received renewed interest given the advances being made in the production of immunocompatible transgenic pigs. However, difficulties are evident in the production of pESCs in-vitro. This may largely be attributable to differences...

  8. Hollow stem in cauliflower

    NARCIS (Netherlands)

    Everaarts, A.P.; Putter, de H.

    2003-01-01

    The occurrence of, sometimes large, cavities in the stem of cauliflower formed a serious quality problem for Dutch cauliflower growers in recent years. The cause of the problem under the local conditions was not clear. In field experiments, the application of boron and variation in the growth rate

  9. Mesenchymal Stem Cells Retain Their Defining Stem Cell Characteristics After Exposure to Ionizing Radiation

    International Nuclear Information System (INIS)

    Nicolay, Nils H.; Sommer, Eva; Lopez, Ramon; Wirkner, Ute; Trinh, Thuy; Sisombath, Sonevisay; Debus, Jürgen; Ho, Anthony D.; Saffrich, Rainer; Huber, Peter E.

    2013-01-01

    Purpose: Mesenchymal stem cells (MSCs) have the ability to migrate to lesion sites and undergo differentiation into functional tissues. Although this function may be important for tissue regeneration after radiation therapy, the influence of ionizing radiation (IR) on cellular survival and the functional aspects of differentiation and stem cell characteristics of MSCs have remained largely unknown. Methods and Materials: Radiation sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells was examined, and cellular morphology, cell cycle effects, apoptosis, and differentiation potential after exposure to IR were assessed. Stem cell gene expression patterns after exposure to IR were studied using gene arrays. Results: MSCs were not more radiosensitive than human primary fibroblasts, whereas there were considerable differences regarding radiation sensitivity within individual MSCs. Cellular morphology, cytoskeletal architecture, and cell motility were not markedly altered by IR. Even after high radiation doses up to 10 Gy, MSCs maintained their differentiation potential. Compared to primary fibroblast cells, MSCs did not show an increase in irradiation-induced apoptosis. Gene expression analyses revealed an upregulation of various genes involved in DNA damage response and DNA repair, but expression of established MSC surface markers appeared only marginally influenced by IR. Conclusions: These data suggest that human MSCs are not more radiosensitive than differentiated primary fibroblasts. In addition, upon photon irradiation, MSCs were able to retain their defining stem cell characteristics both on a functional level and regarding stem cell marker expression

  10. Classification of Hydrogels Based on Their Source: A Review and Application in Stem Cell Regulation

    Science.gov (United States)

    Khansari, Maziyar M.; Sorokina, Lioudmila V.; Mukherjee, Prithviraj; Mukhtar, Farrukh; Shirdar, Mostafa Rezazadeh; Shahidi, Mahnaz; Shokuhfar, Tolou

    2017-08-01

    Stem cells are recognized by their self-renewal ability and can give rise to specialized progeny. Hydrogels are an established class of biomaterials with the ability to control stem cell fate via mechanotransduction. They can mimic various physiological conditions to influence the fate of stem cells and are an ideal platform to support stem cell regulation. This review article provides a summary of recent advances in the application of different classes of hydrogels based on their source (e.g., natural, synthetic, or hybrid). This classification is important because the chemistry of substrate affects stem cell differentiation and proliferation. Natural and synthetic hydrogels have been widely used in stem cell regulation. Nevertheless, they have limitations that necessitate a new class of material. Hybrid hydrogels obtained by manipulation of the natural and synthetic ones can potentially overcome these limitations and shape the future of research in application of hydrogels in stem cell regulation.

  11. Stem cell regenerative potential combined with nanotechnology and tissue engineering for myocardial regeneration.

    Science.gov (United States)

    Calin, Manuela; Stan, Daniela; Simion, Viorel

    2013-07-01

    The stem cell-based therapy for post-infarction myocardial regeneration has been introduced more than a decade ago, but the functional improvement obtained is limited due to the poor retention and short survival rate of transplanted cells into the damaged myocardium. More recently, the emerging nanotechnology concepts for advanced diagnostics and therapy provide promising opportunities of using stem cells for myocardial regeneration. In this paper will be provided an overview of the use of nanotechnology approaches in stem cell research for: 1) cell labeling to track the distribution of stem cells after transplantation, 2) nanoparticle-mediated gene delivery to stem cells to promote their homing, engraftment, survival and differentiation in the ischemic myocardium and 3) obtaining of bio-inspired materials to provide suitable myocardial scaffolds for delivery of stem cells or stem cell-derived factors.

  12. Using laser to measure stem thickness and cut weed stems

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Andreasen, C.

    2002-01-01

    Stem thickness of the weed Solanum nigrum and the crop sugarbeet was determined with a He-Ne laser using a novel non-destructive technique measuring stem shadow. Thereafter, the stems were cut close to the soil surface with a CO2 laser. Treatments were carried out on pot plants, grown....... A binary model was also tested. The non-linear model incorporating stem thickness described the data best, indicating that it would be possible to optimize laser cutting by measuring stem thickness before cutting. The general tendency was that more energy was needed the thicker the stem. Energy uses...... in the greenhouse, at two different growth stages, and plant dry matter was measured 2-5 weeks after treatment. The relationship between plant dry weight and laser energy was analysed using two different non-linear dose-response regression models; one model included stem thickness as a variable, the other did not...

  13. Materialism and food security.

    Science.gov (United States)

    Allen, M W; Wilson, M

    2005-12-01

    The present studies examined if materialists have an elevated concern about food availability, presumably stemming from a general survival security motivation. Study 1 found that materialists set a greater life goal of food security, and reported more food insecurity during their childhood. Materialists reported less present-day food insecurity. Study 2 revealed that materialists stored/hoarded more food at home, and that obese persons endorsed materialism more than low/normal weight persons. Study 3 found that experimentally decreasing participants' feelings of survival security (via a mortality salience manipulation) led to greater endorsement of materialism, food security as goal, and using food for emotional comfort. The results imply that materialists overcame the food insecurity of their childhood by making food security a top life goal, but that materialists' current concerns about food security may not wholly stem from genuine threats to their food supply.

  14. Stem cell migration after irradiation

    International Nuclear Information System (INIS)

    Nothdurft, W.; Fliedner, T.M.

    1979-01-01

    The survival rate of irradiated rodents could be significantly improved by shielding only the small parts of hemopoietic tissues during the course of irradiation. The populations of circulating stem cells in adult organisms are considered to be of some importance for the homeostasis between the many sites of blood cell formation and for the necessary flexibility of hemopoietic response in the face of fluctuating demands. Pluripotent stem cells are migrating through peripheral blood as has been shown for several mammalian species. Under steady state conditions, the exchange of stem cells between the different sites of blood cell formation appears to be restricted. Their presence in blood and the fact that they are in balance with the extravascular stem cell pool may well be of significance for the surveilance of the integrity of local stem cell populations. Any decrease of stem cell population in blood below a critical size results in the rapid immigration of circulating stem cells in order to restore local stem cell pool size. Blood stem cells are involved in the regeneration after whole-body irradiation if the stem cell population in bone marrows is reduced to less than 10% of the normal state. In the animals subjected to partial-body irradiation, the circulating stem cells appear to be the only source for the repopulation of the heavily irradiated, aplastic sites of hemopoietic organs. (Yamashita, S.)

  15. Biochemistry of epidermal stem cells.

    Science.gov (United States)

    Eckert, Richard L; Adhikary, Gautam; Balasubramanian, Sivaprakasam; Rorke, Ellen A; Vemuri, Mohan C; Boucher, Shayne E; Bickenbach, Jackie R; Kerr, Candace

    2013-02-01

    The epidermis is an important protective barrier that is essential for maintenance of life. Maintaining this barrier requires continuous cell proliferation and differentiation. Moreover, these processes must be balanced to produce a normal epidermis. The stem cells of the epidermis reside in specific locations in the basal epidermis, hair follicle and sebaceous glands and these cells are responsible for replenishment of this tissue. A great deal of effort has gone into identifying protein epitopes that mark stem cells, in identifying stem cell niche locations, and in understanding how stem cell populations are related. We discuss these studies as they apply to understanding normal epidermal homeostasis and skin cancer. An assortment of stem cell markers have been identified that permit assignment of stem cells to specific regions of the epidermis, and progress has been made in understanding the role of these cells in normal epidermal homeostasis and in conditions of tissue stress. A key finding is the multiple stem cell populations exist in epidermis that give rise to different structures, and that multiple stem cell types may contribute to repair in damaged epidermis. Understanding epidermal stem cell biology is likely to lead to important therapies for treating skin diseases and cancer, and will also contribute to our understanding of stem cells in other systems. This article is part of a Special Issue entitled Biochemistry of Stem Cells. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Biochemistry of epidermal stem cells☆

    Science.gov (United States)

    Eckert, Richard L.; Adhikary, Gautam; Balasubramanian, Sivaprakasam; Rorke, Ellen A.; Vemuri, Mohan C.; Boucher, Shayne E.; Bickenbach, Jackie R.; Kerr, Candace

    2014-01-01

    Background The epidermis is an important protective barrier that is essential for maintenance of life. Maintaining this barrier requires continuous cell proliferation and differentiation. Moreover, these processes must be balanced to produce a normal epidermis. The stem cells of the epidermis reside in specific locations in the basal epidermis, hair follicle and sebaceous glands and these cells are responsible for replenishment of this tissue. Scope of review A great deal of effort has gone into identifying protein epitopes that mark stem cells, in identifying stem cell niche locations, and in understanding how stem cell populations are related. We discuss these studies as they apply to understanding normal epidermal homeostasis and skin cancer. Major conclusions An assortment of stem cell markers have been identified that permit assignment of stem cells to specific regions of the epidermis, and progress has been made in understanding the role of these cells in normal epidermal homeostasis and in conditions of tissue stress. A key finding is the multiple stem cell populations exist in epidermis that give rise to different structures, and that multiple stem cell types may contribute to repair in damaged epidermis. General significance Understanding epidermal stem cell biology is likely to lead to important therapies for treating skin diseases and cancer, and will also contribute to our understanding of stem cells in other systems. This article is part of a Special Issue entitled Biochemistry of Stem Cells. PMID:22820019

  17. Toward the Development of an Artificial Brain on a Micropatterned and Material-Regulated Biochip by Guiding and Promoting the Differentiation and Neurite Outgrowth of Neural Stem/Progenitor Cells.

    Science.gov (United States)

    Liu, Yung-Chiang; Lee, I-Chi; Lei, Kin Fong

    2018-02-14

    An in vitro model mimicking the in vivo environment of the brain must be developed to study neural communication and regeneration and to obtain an understanding of cellular and molecular responses. In this work, a multilayered neural network was successfully constructed on a biochip by guiding and promoting neural stem/progenitor cell differentiation and network formation. The biochip consisted of 3 × 3 arrays of cultured wells connected with channels. Neurospheroids were cultured on polyelectrolyte multilayer (PEM) films in the culture wells. Neurite outgrowth and neural differentiation were guided and promoted by the micropatterns and the PEM films. After 5 days in culture, a 3 × 3 neural network was constructed on the biochip. The function and the connections of the network were evaluated by immunocytochemistry and impedance measurements. Neurons were generated and produced functional and recyclable synaptic vesicles. Moreover, the electrical connections of the neural network were confirmed by measuring the impedance across the neurospheroids. The current work facilitates the development of an artificial brain on a chip for investigations of electrical stimulations and recordings of multilayered neural communication and regeneration.

  18. [Perinatal sources of stem cells].

    Science.gov (United States)

    Piskorska-Jasiulewicz, Magdalena Maria; Witkowska-Zimny, Małgorzata

    2015-03-08

    Recently, stem cell biology has become an interesting topic. Several varieties of human stem cells have been isolated and identified in vivo and in vitro. Successful application of hematopoietic stem cells in hematology has led to the search for other sources of stem cells and expanding the scale of their application. Perinatal stem cells are a versatile cell population, and they are interesting for both scientific and practical objectives. Stem cells from perinatal tissue may be particularly useful in the clinic for autologous transplantation for fetuses and newborns, and after banking in later stages of life, as well as for in utero transplantation in the case of genetic disorders. In this review paper we focus on the extraction and therapeutic potential of stem cells derived from perinatal tissues such as the placenta, the amnion, amniotic fluid, umbilical cord blood and Wharton's jelly.

  19. Perinatal sources of stem cells

    Directory of Open Access Journals (Sweden)

    Magdalena Maria Piskorska-Jasiulewicz

    2015-03-01

    Full Text Available Recently, stem cell biology has become an interesting topic. Several varieties of human stem cells have been isolated and identified in vivo and in vitro. Successful application of hematopoietic stem cells in hematology has led to the search for other sources of stem cells and expanding the scale of their application. Perinatal stem cells are a versatile cell population, and they are interesting for both scientific and practical objectives. Stem cells from perinatal tissue may be particularly useful in the clinic for autologous transplantation for fetuses and newborns, and after banking in later stages of life, as well as for in utero transplantation in the case of genetic disorders. In this review paper we focus on the extraction and therapeutic potential of stem cells derived from perinatal tissues such as the placenta, the amnion, amniotic fluid, umbilical cord blood and Wharton’s jelly.

  20. Derivation of porcine pluripotent stem cells for biomedical research.

    Science.gov (United States)

    Shiue, Yow-Ling; Yang, Jenn-Rong; Liao, Yu-Jing; Kuo, Ting-Yung; Liao, Chia-Hsin; Kang, Ching-Hsun; Tai, Chein; Anderson, Gary B; Chen, Lih-Ren

    2016-07-01

    Pluripotent stem cells including embryonic stem cells (ESCs), embryonic germ cells (EGCs), and induced pluripotent stem cells (iPSCs) are capable of self-renew and limitlessly proliferating in vitro with undifferentiated characteristics. They are able to differentiate in vitro, spontaneously or responding to suitable signals, into cells of all three primary germ layers. Consequently, these pluripotent stem cells will be valuable sources for cell replacement therapy in numerous disorders. However, the promise of human ESCs and EGCs is cramped by the ethical argument about destroying embryos and fetuses for cell line creation. Moreover, there are still carcinogenic risks existing toward the goal of clinical application for human ESCs, EGCs, and iPSCs. Therefore, a suitable animal model for stem cell research will benefit the further development of human stem cell technology. The pigs, on the basis of their similarity in anatomy, immunology, physiology, and biochemical properties, have been wide used as model animals in the study of various human diseases. The development of porcine pluripotent stem cell lines will hold the opportunity to provide an excellent material for human counterpart to the transplantation in biomedical research and further development of cell-based therapeutic strategy. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Stem cell responses to plasma surface modified electrospun polyurethane scaffolds.

    Science.gov (United States)

    Zandén, Carl; Hellström Erkenstam, Nina; Padel, Thomas; Wittgenstein, Julia; Liu, Johan; Kuhn, H Georg

    2014-07-01

    The topographical effects from functional materials on stem cell behavior are currently of interest in tissue engineering and regenerative medicine. Here we investigate the influence of argon, oxygen, and hydrogen plasma surface modification of electrospun polyurethane fibers on human embryonic stem cell (hESC) and rat postnatal neural stem cell (NSC) responses. The plasma gases were found to induce three combinations of fiber surface functionalities and roughness textures. On randomly oriented fibers, plasma treatments lead to substantially increased hESC attachment and proliferation as compared to native fibers. Argon plasma was found to induce the most optimal combination of surface functionality and roughness for cell expansion. Contact guided migration of cells and alignment of cell processes were observed on aligned fibers. Neuronal differentiation around 5% was found for all samples and was not significantly affected by the induced variations of surface functional group distribution or individual fiber topography. In this study the influence of argon, oxygen, and hydrogen plasma surface modification of electrospun polyurethane fibers on human embryonic stem cell and rat postnatal neural stem cell (NSC) responses is studied with the goal of clarifying the potential effects of functional materials on stem cell behavior, a topic of substantial interest in tissue engineering and regenerative medicine. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Perspectives of stem cell use in reconstructive maxillofacial surgery

    Directory of Open Access Journals (Sweden)

    Mikhail G. Semyonov

    2016-12-01

    Full Text Available The discovery of stem cells is one of the greatest achievements of molecular and cell biology, and associated research has confirmed the possibility of self-renewal and differentiation into specialized tissue stem cells. The use of cellular technologies is an important trend in modern medicine. The aim of this article is to briefly review current findings on the use of stem cells in cardiology, endocrinology, neurology, traumatology, and maxillofacial surgery. All data were retrieved from experimental and clinical studies using various cell technologies. The material is part of ongoing maxillofacial surgery research to investigate the possible use of stem cells in reconstructive maxillofacial surgery for jaw bone pathologies in children. Present tissue engineering methods provide some opportunities for solving difficult clinical problems in oral and maxillofacial surgery. Despite some international achievements of effective application of IC in various diseases, clinical use in reconstructive surgery requires further investigation.

  3. Imaging and 1-day kinetics of intracoronary stem cell transplantation in patients with idiopathic dilated cardiomyopathy

    International Nuclear Information System (INIS)

    Lezaic, Luka; Socan, Aljaz; Peitl, Petra Kolenc; Poglajen, Gregor; Sever, Matjaz; Cukjati, Marko; Cernelc, Peter; Vrtovec, Bojan

    2016-01-01

    Background: Stem cell transplantation is an emerging method of treatment for patients with cardiovascular disease. There are few studies completed or ongoing on stem cell therapy in patients with idiopathic dilated cardiomyopathy (IDCM). Information on stem cell homing and distribution in the myocardium after transplantation might provide important insight into effectiveness of transplantation procedure. Aim: To assess early engraftment, retention and migration of intracoronarily transplanted stem cells in the myocardium of patients with advanced dilated cardiomyopathy of non-ischaemic origin using stem cell labeling with 99m Tc-exametazime (HMPAO). Materials, methods: Thirty-five patients with IDCM and advanced heart failure were included in the study. Autologous hematopoietic (CD34 +) stem cells were harvested by peripheral blood apheresis after bone marrow stimulation, labeled with 99m Tc-HMPAO, tested for viability and injected into coronary vessel supplying areas of myocardium selected by myocardial perfusion scintigraphy as dysfunctional yet viable. Imaging was performed 1 h and 18 h after transplantation. Results: Myocardial stem cell retention ranged from 0 to 1.44% on early and 0–0.97% on delayed imaging. Significant efflux of stem cells occurred from site of delivery in this time period (p < 0.001). Stem cell viability was not affected by labeling. Conclusion: Stem cell labeling with 99m Tc-HMPAO is a feasible method for stem cell tracking after transplantation in patients with IDCM.

  4. The Problem about Technology in STEM Education: Some Findings from Action Research on the Professional Development & Integrated STEM Lessons in Informal Fields

    Directory of Open Access Journals (Sweden)

    Tomoki Saito

    2015-04-01

    Full Text Available Since 2013, the authors’ Japanese team in the Department of Science Education at Shizuoka University has held trials of STEM Education in informal fields as participatory action research (e.g., Science museum in Shizuoka, Lifelong Learning Center in Fujieda City, and STEM Summer camp for the preparation for implementing STEM education in public schools and for proposing science education reform in a Japanese context. Problems in preparing STEM lessons include numerous new instructional materials and programs and emerging specialized schools. In addition, while most of these initiatives address one or more of the STEM subjects separately, there are increasing calls for emphasizing connections between and among the subjects (Honey, Pearson and Schweingruber, 2014. Unfamiliar problems for Japanese teachers are, What is Engineering? What is Design? and How can they be implemented in lessons? While gathering STEM learning materials to implement in their STEM Summer Camp, the authors noticed a pattern with which to develop a STEM lesson and developed a template “T-SM-E” in reference to prior STEM studies. After the STEM Summer Camp, the authors introduced the model in the pre-service teacher preparation program. As a result, the authors received suggestions about how teachers can develop integrated STEM lessons, how undergraduate (UG teachers can implement it in their lessons, and how teachers can assess student learning in their STEM lessons. From standard based student assessments and reflections written by the UG teachers, the authors found that it was difficult for the UG teachers to include technology in their lessons, and their assessment also indicated that the students did not show performance proficiency in technology. The authors discuss this existing problem in the Japanese education system.

  5. Stem cells in psoriasis.

    Science.gov (United States)

    Hou, Ruixia; Li, Junqin; Niu, Xuping; Liu, Ruifeng; Chang, Wenjuan; Zhao, Xincheng; Wang, Qiang; Li, Xinhua; Yin, Guohua; Zhang, Kaiming

    2017-06-01

    Psoriasis is a complex chronic relapsing inflammatory disease. Although the exact mechanism remains unknown, it is commonly accepted that the development of psoriasis is a result of multi-system interactions among the epidermis, dermis, blood vessels, immune system, neuroendocrine system, metabolic system, and hematopoietic system. Many cell types have been confirmed to participate in the pathogenesis of psoriasis. Here, we review the stem cell abnormalities related to psoriasis that have been investigated recently. Copyright © 2016. Published by Elsevier B.V.

  6. Engaging learners in STEM education

    Directory of Open Access Journals (Sweden)

    Joseph Krajcik

    2017-04-01

    Full Text Available In this manuscript we focus on how to develop STEM learning environments, and how STEM can be implemented in K-12 schools. We focus on the following question: “How can we support students in building a deep, integrated knowledge of STEM so that they have the practical knowledge and problem solving skills necessary to live in and improve the world?” We also discuss criteria for evaluating STEM learning environments and the challenges teachers face in implementing STEM. We define STEM as the integration of science, engineering, technology, and mathematics to focus on solving pressing individual and societal problems. Engaging students in STEM also means engaging learners in the design process. Design is integral to student thinking in the STEM world. The design process is very non-linear and iterative in its nature but requires clearly articulating and identifying the design problem, researching what is known about the problem, generating potential solutions, developing prototype designs (artifacts that demonstrate solutions, and sharing and receiving feedback. With the integration of design, STEM education has the potential to support students in learning big ideas in science and engineering, as well as important scientific and engineering practices, and support students in developing important motivational outcomes such as ownership, agency and efficacy. Moreover, students who engage in STEM learning environments will also develop 21st century capabilities such as problem solving, communication, and collaboration skills.

  7. Gastric stem cells and gastric cancer stem cells

    OpenAIRE

    Han, Myoung-Eun; Oh, Sae-Ock

    2013-01-01

    The gastric epithelium is continuously regenerated by gastric stem cells, which give rise to various kinds of daughter cells, including parietal cells, chief cells, surface mucous cells, mucous neck cells, and enteroendocrine cells. The self-renewal and differentiation of gastric stem cells need delicate regulation to maintain the normal physiology of the stomach. Recently, it was hypothesized that cancer stem cells drive the cancer growth and metastasis. In contrast to conventional clonal ev...

  8. Concise Review: Bioprinting of Stem Cells for Transplantable Tissue Fabrication.

    Science.gov (United States)

    Leberfinger, Ashley N; Ravnic, Dino J; Dhawan, Aman; Ozbolat, Ibrahim T

    2017-10-01

    Bioprinting is a quickly progressing technology, which holds the potential to generate replacement tissues and organs. Stem cells offer several advantages over differentiated cells for use as starting materials, including the potential for autologous tissue and differentiation into multiple cell lines. The three most commonly used stem cells are embryonic, induced pluripotent, and adult stem cells. Cells are combined with various natural and synthetic materials to form bioinks, which are used to fabricate scaffold-based or scaffold-free constructs. Computer aided design technology is combined with various bioprinting modalities including droplet-, extrusion-, or laser-based bioprinting to create tissue constructs. Each bioink and modality has its own advantages and disadvantages. Various materials and techniques are combined to maximize the benefits. Researchers have been successful in bioprinting cartilage, bone, cardiac, nervous, liver, and vascular tissues. However, a major limitation to clinical translation is building large-scale vascularized constructs. Many challenges must be overcome before this technology is used routinely in a clinical setting. Stem Cells Translational Medicine 2017;6:1940-1948. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  9. Immobilization of heparan sulfate on electrospun meshes to support embryonic stem cell culture and differentiation

    NARCIS (Netherlands)

    Meade, K.A.; White, K.J.; Pickford, C.E.; Holley, R.J.; Marson, A.; Tillotson, D.; Kuppevelt, A.H.M.S.M. van; Whittle, J.D.; Day, A.J.; Merry, C.L.

    2013-01-01

    As our understanding of what guides the behavior of multi- and pluripotent stem cells deepens, so too does our ability to utilize certain cues to manipulate their behavior and maximize their therapeutic potential. Engineered, biologically functionalized materials have the capacity to influence stem

  10. Stem cells in dentistry--part I: stem cell sources.

    Science.gov (United States)

    Egusa, Hiroshi; Sonoyama, Wataru; Nishimura, Masahiro; Atsuta, Ikiru; Akiyama, Kentaro

    2012-07-01

    Stem cells can self-renew and produce different cell types, thus providing new strategies to regenerate missing tissues and treat diseases. In the field of dentistry, adult mesenchymal stem/stromal cells (MSCs) have been identified in several oral and maxillofacial tissues, which suggests that the oral tissues are a rich source of stem cells, and oral stem and mucosal cells are expected to provide an ideal source for genetically reprogrammed cells such as induced pluripotent stem (iPS) cells. Furthermore, oral tissues are expected to be not only a source but also a therapeutic target for stem cells, as stem cell and tissue engineering therapies in dentistry continue to attract increasing clinical interest. Part I of this review outlines various types of intra- and extra-oral tissue-derived stem cells with regard to clinical availability and applications in dentistry. Additionally, appropriate sources of stem cells for regenerative dentistry are discussed with regard to differentiation capacity, accessibility and possible immunomodulatory properties. Copyright © 2012 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  11. Stem Cell Transplantation from Bench to Bedside

    Indian Academy of Sciences (India)

    Table of contents. Stem Cell Transplantation from Bench to Bedside · Slide 2 · Slide 3 · Slide 4 · Principles of an allogeneic stem cell transplant · Principle of an allogeneic stem cell transplant · Principle of an autologous Stem Cell Transplant · Slide 8 · Conditioning · Slide 10 · Slide 11 · Stem Cell Transplantation · Slide 13.

  12. Stem cells: basic research on health, from ethics to panacea

    Directory of Open Access Journals (Sweden)

    Naara Luna

    2007-01-01

    Full Text Available Even though stem cell therapies are still under experimentation, the media has represented them as a panacea that would cure all diseases. This fact secured the authorization for using human embryos as research material. Therapies include manipulation of human material in tissue bioengineering, suggesting a representation of the body as a factory. This article describes stem cell research projects being carried out in the health sciences center of a higher education institution, focusing on field organization and on the system of values underlying scientific activity. Researchers at different levels were interviewed about perspectives on, and implications of, their research in order to analyze the discourse of the projects' participants. Experiments with adult stem cells enjoyed wide support, while the use of human embryos was disputed. The foundations of those arguments were sought in their relation both to the structure of the scientific field and to the researchers' religious background.

  13. Limbal Stem Cell Deficiency and Treatment with Stem Cell Transplantation.

    Science.gov (United States)

    Barut Selver, Özlem; Yağcı, Ayşe; Eğrilmez, Sait; Gürdal, Mehmet; Palamar, Melis; Çavuşoğlu, Türker; Ateş, Utku; Veral, Ali; Güven, Çağrı; Wolosin, Jose Mario

    2017-10-01

    The cornea is the outermost tissue of the eye and it must be transparent for the maintenance of good visual function. The superficial epithelium of the cornea, which is renewed continuously by corneal stem cells, plays a critical role in the permanence of this transparency. These stem cells are localized at the cornea-conjunctival transition zone, referred to as the limbus. When this zone is affected/destroyed, limbal stem cell deficiency ensues. Loss of limbal stem cell function allows colonization of the corneal surface by conjunctival epithelium. Over 6 million people worldwide are affected by corneal blindness, and limbal stem cell deficiency is one of the main causes. Fortunately, it is becoming possible to recover vision by autologous transplantation of limbal cells obtained from the contralateral eye in unilateral cases. Due to the potential risks to the donor eye, only a small amount of tissue can be obtained, in which only 1-2% of the limbal epithelial cells are actually limbal stem cells. Vigorous attempts are being made to expand limbal stem cells in culture to preserve or even enrich the stem cell population. Ex vivo expanded limbal stem cell treatment in limbal stem cell deficiency was first reported in 1997. In the 20 years since, various protocols have been developed for the cultivation of limbal epithelial cells. It is still not clear which method promotes effective stem cell viability and this remains a subject of ongoing research. The most preferred technique for limbal cell culture is the explant culture model. In this approach, a small donor eye limbal biopsy is placed as an explant onto a biocompatible substrate (preferably human amniotic membrane) for expansion. The outgrowth (cultivated limbal epithelial cells) is then surgically transferred to the recipient eye. Due to changing regulations concerning cell-based therapy, the implementation of cultivated limbal epithelial transplantation in accordance with Good Laboratory Practice using

  14. Traumatic primary brain stem haemorrhage

    International Nuclear Information System (INIS)

    Andrioli, G.C.; Zuccarello, M.; Trincia, G.; Fiore, D.L.; De Caro, R.

    1983-01-01

    We report 36 cases of post-traumatic 'primary brain stem haemorrhage' visualized by the CT scan and confirmed at autopsy. Clinical experience shows that many technical factors influence the inability to visualize brain stem haemorrhages. Experimental injection of fresh blood into the pons and midbrain of cadavers shows that lesions as small as 0.25 ml in volume may be visualized. The volume and the anatomical configuration of traumatic lesions of the brain stem extended over a rostro-caudal direction, and their proximity to bony structures at the base of the skull are obstacles to the visualization of brain stem haemorrhages. (Author)

  15. STEm Minority Graduate Program

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas, Kaen E

    2012-09-20

    ABSTRACT The state of science, technology, engineering and math (STEM) education in the United States has seen some unfavorable assessments over the past decade. In early February, 2010 the House of Representatives heard testimony on undergraduate and graduate education. The message from the panel, which included experts from academia, STEM-based industries, and the National Science Foundation (NSF) was dire and required an urgent response. The experts along with the committee's chairperson, U. S. Representative Daniel Lipinski (D-IL) cited that the complexity of Science, Technology, Engineering, and Mathematics applications and coursework and the methodology utilized to teach these subjects are forcing students out of these disciplines. As the National Academies described in its 2007 report Rising Above the Gathering Storm, successful STEM education is not just an academic pursuit it's a necessity for competing in the knowledge-based economy that the United States had a key role in creating. The potential for action is being made available again as the America COMPETES Act of 2007 is up for reauthorization. Its initial focus was on STEM education at the K-12 levels, but efforts at the undergraduate and graduate levels are needed to retain students to fill the jobs left vacant as baby boomers retire. The Educational Advancement Alliance, Inc. (EAA) has for two decades created programs that have not only addressed the issues of ensuring that students are aptly prepared for college but have focused its efforts over the past decade on increasing the number of students who pursue degrees in STEM disciplines. For the EAA, the introduction of the wonders of science begins at the elementary and middle school level via the Learning Lab, a state-of-the-art mobile science laboratory that visits students in grades 4-6 at the various schools throughout Philadelphia and The Math/Tech Academy which meets on Saturdays for students in grades 5-7. For the past two years

  16. The effect of cement on hip stem fixation: a biomechanical study.

    Science.gov (United States)

    Çelik, Talip; Mutlu, İbrahim; Özkan, Arif; Kişioğlu, Yasin

    2017-06-01

    This study presents the numerical analysis of stem fixation in hip surgery using with/without cement methods since the use of cement is still controversial based on the clinical studies in the literature. Many different factors such as stress shielding, aseptic loosening, material properties of the stem, surgeon experiences etc. play an important role in the failure of the stem fixations. The stem fixation methods, cemented and uncemented, were evaluated in terms of mechanical failure aspects using computerized finite element method. For the modeling processes, three dimensional (3D) femur model was generated from computerized tomography (CT) images taken from a patient using the MIMICS Software. The design of the stem was also generated as 3D CAD model using the design parameters taken from the manufacturer catalogue. These 3D CAD models were generated and combined with/without cement considering the surgical procedure using SolidWorks program and then imported into ANSYS Workbench Software. Two different material properties, CoCrMo and Ti6Al4V, for the stem model and Poly Methyl Methacrylate (PMMA) for the cement were assigned. The material properties of the femur were described according to a density calculated from the CT images. Body weight and muscle forces were applied on the femur and the distal femur was fixed for the boundary conditions. The calculations of the stress distributions of the models including cement and relative movements of the contacts examined to evaluate the effects of the cement and different stem material usage on the failure of stem fixation. According to the results, the use of cement for the stem fixation reduces the stress shielding but increases the aseptic loosening depending on the cement crack formations. Additionally, using the stiffer material for the stem reduces the cement stress but increases the stress shielding. Based on the results obtained in the study, even when taking the disadvantages into account, the cement usage

  17. Fragmentation, Cost and Environmental Effects of Plaster Stemming Method for Blasting at A Basalt Quarry

    Science.gov (United States)

    Cevizci, Halim

    2014-10-01

    In this study, the plaster stemming application for blasting at a basalt quarry is studied. Drill cuttings are generally used in open pits and quarries as the most common stemming material since these are most readily available at blast sites. However, dry drill cuttings eject very easily from blastholes without offering much resistance to blast energy. The plaster stemming method has been found to be better than the drill cuttings stemming method due to increased confinement inside the hole and better utilization of blast explosive energy in the rock. The main advantage of the new stemming method is the reduction in the cost of blasting. At a basalt quarry, blasting costs per unit volume of rock were reduced to 15% by increasing burden and spacing distances. In addition, better fragmentation was obtained by using the plaster stemming method. Blast trials showed that plaster stemming produced finer material. In the same blast tests, +30 cm size fragments were reduced to 47.3% of the total, compared to 32.6% in the conventional method of drill cuttings stemming. With this method of stemming, vibration and air shock values increased slightly due to more blast energy being available for rock breakage but generally these increased values were small and stayed under the permitted limit for blast damage criteria unless measuring distance is too close.

  18. Learning for STEM Literacy: STEM Literacy for Learning

    Science.gov (United States)

    Zollman, Alan

    2012-01-01

    We are in the STEM generation whose comprehensive purpose is to resolve (1) societal needs for new technological and scientific advances; (2) economic needs for national security; and (3) personal needs to become a fulfilled, productive, knowledgeable citizen. STEM specifically refers to science, technology, engineering, and mathematics, but now…

  19. Aging, metabolism and stem cells: Spotlight on muscle stem cells.

    Science.gov (United States)

    García-Prat, Laura; Muñoz-Cánoves, Pura

    2017-04-15

    All tissues and organs undergo a progressive regenerative decline as they age. This decline has been mainly attributed to loss of stem cell number and/or function, and both stem cell-intrinsic changes and alterations in local niches and/or systemic environment over time are known to contribute to the stem cell aging phenotype. Advancing in the molecular understanding of the deterioration of stem cell cells with aging is key for targeting the specific causes of tissue regenerative dysfunction at advanced stages of life. Here, we revise exciting recent findings on why stem cells age and the consequences on tissue regeneration, with a special focus on regeneration of skeletal muscle. We also highlight newly identified common molecular pathways affecting diverse types of aging stem cells, such as altered proteostasis, metabolism, or senescence entry, and discuss the questions raised by these findings. Finally, we comment on emerging stem cell rejuvenation strategies, principally emanating from studies on muscle stem cells, which will surely burst tissue regeneration research for future benefit of the increasing human aging population. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. STEM CELLS IN THE TREATMENT OF URINARY STRESS INCONTINENCE – A VISION OF FUTURE?

    Directory of Open Access Journals (Sweden)

    Adolf Lukanović

    2018-02-01

    Full Text Available Background. For one third of all women urinary incontinence is a health problem. Different strategies of treatment have been used, namely surgical, medical and physiotherapy. To this armamentarium a new method – adult stem cells therapy – has been added. Methods. The source of adult autologues multipotent stem cells consists of muscle-derived stem cells, adipose-derived stem cells and mesenchymed bone marrow cells. In facilities for stem cells with processing and in the presence of specific inducing factors, muscle derived stem cells can be differentiated to striated or smooth muscles. Clinical work is based on animal models that with immunohistochemical analysis demonstrated new skeletal-muscle fiber formation at the site of injection of stem cells. In stress urinary incontinence (SUI autologues bioptic material is obtained by using a musle needle biopsy device. From the biopsy speciment with dissociation muscle-derived stem cells are isolated and injected under local anaesthesia in the middle urethra and/or external urethral sphincter. Initial results of SUI treatment with adult muscle-derived stem cells suggest that perspectives of this method are encouraging. Conclusions. Stem cell therapy is promising to become minimally invasive method for reconstruction of the muscles and connective tissue of urethra and external urethral sphincter.

  1. Directional differentiation of chicken embryonic stem cells into ...

    African Journals Online (AJOL)

    Chicken embryonic stem (ES) cells are useful for producing transgenic chickens and preserving genetic material in avian species. In this study, the differentiation potential of chicken ES cells was investigated in vitro. Chicken ES cells were differentiated into osteoblasts cultured for 15 to 21 days in the induction media ...

  2. Biomaterials Influence Macrophage-Mesenchymal Stem Cell Interaction In Vitro

    NARCIS (Netherlands)

    N. Grotenhuis (Nienke); S.F. De Witte (Samantha Fh); G.J.V.M. van Osch (Gerjo); Y. Bayon (Yves); J.F. Lange (Johan); Y.M. Bastiaansen-Jenniskens (Yvonne)

    2016-01-01

    textabstractBackground: Macrophages and mesenchymal stem cells (MSCs) are important cells in wound healing. We hypothesized that the cross-talk between macrophages and adipose tissue-derived MSCs (ASCs) is biomaterial dependent, thereby influencing processes involved in wound healing. Materials and

  3. Emplacement and stemming of nuclear explosives for Plowshare applications

    International Nuclear Information System (INIS)

    Cramer, J.L.

    1970-01-01

    This paper will discuss the various methods used for emplacement and design considerations that must be taken into account when the emplacement and stemming method is selected. The step-by-step field procedure will not be discussed in this paper. The task of emplacing and stemming the nuclear explosive is common to all Plowshare experiments today. All present-day applications of a nuclear explosive for Plowshare experiments require that the detonation take place some distance below the surface of the ground. This is normally done by lowering the explosive into an emplacement hole to a desired depth and then backfilling the hole with a suitable stemming material. At first glance it scenes like a very straightforward, simple task to perform. It would appear to be a task that could become a standard procedure for all experiments; however, this is not the case. In actuality, the emplacement and stemming of a nuclear explosive must almost be a custom design. It varies with the application of the experiment, i.e., cratering or underground engineering. It also varies with the condition of the hole, the available equipment to do the job, the actual purpose of the stemming, possible postshot reentry, hydrology, geology, and future production. A very important item that must always be considered is the protection of the firing and signal cables during the downhole and stemming operation. Each of these things must be considered; ignoring any one of them could jeopardize one of the objectives of the experiment or perhaps even the experiment itself. It should be emphasized that for a multiple-shot program such as would be used to develop a gas field where the geology, depths of burial etc. are the same, the emplacement and stemming operation would be standardized, as would all other parts of the program. However, for individual experiments in totally different areas, complete standardization of the emplacement and stemming is impossible

  4. Emplacement and stemming of nuclear explosives for Plowshare applications

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, J L [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-15

    This paper will discuss the various methods used for emplacement and design considerations that must be taken into account when the emplacement and stemming method is selected. The step-by-step field procedure will not be discussed in this paper. The task of emplacing and stemming the nuclear explosive is common to all Plowshare experiments today. All present-day applications of a nuclear explosive for Plowshare experiments require that the detonation take place some distance below the surface of the ground. This is normally done by lowering the explosive into an emplacement hole to a desired depth and then backfilling the hole with a suitable stemming material. At first glance it scenes like a very straightforward, simple task to perform. It would appear to be a task that could become a standard procedure for all experiments; however, this is not the case. In actuality, the emplacement and stemming of a nuclear explosive must almost be a custom design. It varies with the application of the experiment, i.e., cratering or underground engineering. It also varies with the condition of the hole, the available equipment to do the job, the actual purpose of the stemming, possible postshot reentry, hydrology, geology, and future production. A very important item that must always be considered is the protection of the firing and signal cables during the downhole and stemming operation. Each of these things must be considered; ignoring any one of them could jeopardize one of the objectives of the experiment or perhaps even the experiment itself. It should be emphasized that for a multiple-shot program such as would be used to develop a gas field where the geology, depths of burial etc. are the same, the emplacement and stemming operation would be standardized, as would all other parts of the program. However, for individual experiments in totally different areas, complete standardization of the emplacement and stemming is impossible.

  5. University Festival Promotes STEM Education

    Science.gov (United States)

    Quagliata, Andrew B.

    2015-01-01

    STEM education is argued as an essential ingredient in preparing our children for careers of the future. This study describes a university festival that includes the promotion of STEM-related career interests in young people among its goals. A total of 203 participants between the age of 7 and 17 completed both pre-event and post-event surveys. In…

  6. Counting stem cells : methodological constraints

    NARCIS (Netherlands)

    Bystrykh, Leonid V.; Verovskaya, Evgenia; Zwart, Erik; Broekhuis, Mathilde; de Haan, Gerald

    The number of stem cells contributing to hematopoiesis has been a matter of debate. Many studies use retroviral tagging of stem cells to measure clonal contribution. Here we argue that methodological factors can impact such clonal analyses. Whereas early studies had low resolution, leading to

  7. Stem cell function and maintenance

    Indian Academy of Sciences (India)

    Stem cell research holds a promise to treat and prevent age-related degenerative changes in humans. Literature is replete with studies showing that stem cell function declines with aging, especially in highly proliferative tissues/organs. Among others, telomerase and telomere damage is one of the intrinsic physical ...

  8. Lasers, stem cells, and COPD

    Directory of Open Access Journals (Sweden)

    De Necochea-Campion Rosalia

    2010-02-01

    Full Text Available Abstract The medical use of low level laser (LLL irradiation has been occurring for decades, primarily in the area of tissue healing and inflammatory conditions. Despite little mechanistic knowledge, the concept of a non-invasive, non-thermal intervention that has the potential to modulate regenerative processes is worthy of attention when searching for novel methods of augmenting stem cell-based therapies. Here we discuss the use of LLL irradiation as a "photoceutical" for enhancing production of stem cell growth/chemoattractant factors, stimulation of angiogenesis, and directly augmenting proliferation of stem cells. The combination of LLL together with allogeneic and autologous stem cells, as well as post-mobilization directing of stem cells will be discussed.

  9. Bioprinting for stem cell research

    Science.gov (United States)

    Tasoglu, Savas; Demirci, Utkan

    2012-01-01

    Recently, there has been a growing interest to apply bioprinting techniques to stem cell research. Several bioprinting methods have been developed utilizing acoustics, piezoelectricity, and lasers to deposit living cells onto receiving substrates. Using these technologies, spatially defined gradients of immobilized proteins can be engineered to direct stem cell differentiation into multiple subpopulations of different lineages. Stem cells can also be patterned in a high-throughput manner onto flexible implementation patches for tissue regeneration or onto substrates with the goal of accessing encapsulated stem cell of interest for genomic analysis. Here, we review recent achievements with bioprinting technologies in stem cell research, and identify future challenges and potential applications including tissue engineering and regenerative medicine, wound healing, and genomics. PMID:23260439

  10. Exploring Earth Systems Through STEM

    Science.gov (United States)

    Chen, Loris; Salmon, Jennifer; Burns, Courtney

    2015-04-01

    During the 2010 school year, grade 8 science teachers at Dwight D. Eisenhower Middle School in Wyckoff, New Jersey, began using the draft of A Framework for K-12 Science Education to transition to the Next Generation Science Standards. In an evolutionary process of testing and revising, teachers work collaboratively to develop problem-based science, technology, engineering, and mathematics (STEM) units that integrate earth science, physical science, and life science topics. Students explore the interconnections of Earth's atmosphere, lithosphere, hydrosphere, and biosphere through problem-based learning. Problem-based learning engages students in (1) direct observations in the field and classroom, (2) collection and analysis of data from remote sensors and hand-held sensors, and (3) analysis of physical, mathematical, and virtual models. Students use a variety of technologies and applications in their investigations, for example iPad apps, Google Classroom, and Vernier sensors. Data from NASA, NOAA, non-government organizations, and scientific research papers inspire student questions and spark investigations. Teachers create materials and websites to support student learning. Teachers curate reading, video, simulations, and other Internet resources for students. Because curriculum is standards-based as opposed to textbook-based, teacher participation in workshops and institutes frequently translates into new or improved study units. Recent programs include Toyota International Teacher Program to Costa Rica, Japan Society Going Global, Siemens STEM Academy, U.S. Naval Academy SET Sail, and NJSTA Maitland P. Simmons Memorial Award Summer Institute. Unit themes include weather and climate, introduction to general chemistry and biochemistry, and cells and heredity. Each if the three 12-week units has embedded engineering challenges inspired by current events, community needs, and/or the work of scientists. The unit segments begin with a problem, progress to

  11. Dictionary materials engineering, materials testing

    International Nuclear Information System (INIS)

    1994-01-01

    This dictionary contains about 9,500 entries in each part of the following fields: 1) Materials using and selection; 2) Mechanical engineering materials -Metallic materials - Non-metallic inorganic materials - Plastics - Composites -Materials damage and protection; 3) Electrical and electronics materials -Conductor materials - Semiconductors - magnetic materials - Dielectric materials - non-conducting materials; 4) Materials testing - Mechanical methods - Analytical methods - Structure investigation - Complex methods - Measurement of physical properties - Non-destructive testing. (orig.) [de

  12. Tumorigenic hybrids between mesenchymal stem cells and gastric cancer cells enhanced cancer proliferation, migration and stemness

    International Nuclear Information System (INIS)

    Xue, Jianguo; Zhu, Yuan; Sun, Zixuan; Ji, Runbi; Zhang, Xu; Xu, Wenrong; Yuan, Xiao; Zhang, Bin; Yan, Yongmin; Yin, Lei; Xu, Huijuan; Zhang, Leilei; Zhu, Wei; Qian, Hui

    2015-01-01

    Emerging evidence indicates that inappropriate cell-cell fusion might contribute to cancer progression. Similarly, mesenchymal stem cells (MSCs) can also fuse with other cells spontaneously and capable of adopting the phenotype of other cells. The aim of our study was to investigate the role of MSCs participated cell fusion in the tumorigenesis of gastric cancer. We fused human umbilical cord mesenchymal stem cells (hucMSCs) with gastric cancer cells in vitro by polyethylene glycol (PEG), the hybrid cells were sorted by flow cytometer. The growth and migration of hybrids were assessed by cell counting, cell colony formation and transwell assays. The proteins and genes related to epithelial-mesenchymal transition and stemness were tested by western blot, immunocytochemistry and real-time RT-PCR. The expression of CD44 and CD133 was examined by immunocytochemistry and flow cytometry. The xenograft assay was used to evaluation the tumorigenesis of the hybrids. The obtained hybrids exhibited epithelial- mesenchymal transition (EMT) change with down-regulation of E-cadherin and up-regulation of Vimentin, N-cadherin, α-smooth muscle actin (α-SMA), and fibroblast activation protein (FAP). The hybrids also increased expression of stemness factors Oct4, Nanog, Sox2 and Lin28. The expression of CD44 and CD133 on hybrid cells was stronger than parental gastric cancer cells. Moreover, the migration and proliferation of heterotypic hybrids were enhanced. In addition, the heterotypic hybrids promoted the growth abilities of gastric xenograft tumor in vivo. Taken together, our results suggest that cell fusion between hucMSCs and gastric cancer cells could contribute to tumorigenic hybrids with EMT and stem cell-like properties, which may provide a flexible tool for investigating the roles of MSCs in gastric cancer. The online version of this article (doi:10.1186/s12885-015-1780-1) contains supplementary material, which is available to authorized users

  13. Haematopoietic stem and progenitor cells from human pluripotent stem cells

    Science.gov (United States)

    Sugimura, Ryohichi; Jha, Deepak Kumar; Han, Areum; Soria-Valles, Clara; da Rocha, Edroaldo Lummertz; Lu, Yi-Fen; Goettel, Jeremy A.; Serrao, Erik; Rowe, R. Grant; Malleshaiah, Mohan; Wong, Irene; Sousa, Patricia; Zhu, Ted N.; Ditadi, Andrea; Keller, Gordon; Engelman, Alan N.; Snapper, Scott B.; Doulatov, Sergei; Daley, George Q.

    2018-01-01

    A variety of tissue lineages can be differentiated from pluripotent stem cells by mimicking embryonic development through stepwise exposure to morphogens, or by conversion of one differentiated cell type into another by enforced expression of master transcription factors. Here, to yield functional human haematopoietic stem cells, we perform morphogen-directed differentiation of human pluripotent stem cells into haemogenic endothelium followed by screening of 26 candidate haematopoietic stem-cell-specifying transcription factors for their capacity to promote multi-lineage haematopoietic engraftment in mouse hosts. We recover seven transcription factors (ERG, HOXA5, HOXA9, HOXA10, LCOR, RUNX1 and SPI1) that are sufficient to convert haemogenic endothelium into haematopoietic stem and progenitor cells that engraft myeloid, B and T cells in primary and secondary mouse recipients. Our combined approach of morphogen-driven differentiation and transcription-factor-mediated cell fate conversion produces haematopoietic stem and progenitor cells from pluripotent stem cells and holds promise for modelling haematopoietic disease in humanized mice and for therapeutic strategies in genetic blood disorders. PMID:28514439

  14. Guiding osteogenesis of mesenchymal stem cells using carbon-based nanomaterials

    Science.gov (United States)

    Kang, Ee-Seul; Kim, Da-Seul; Suhito, Intan Rosalina; Choo, Sung-Sik; Kim, Seung-Jae; Song, Inbeom; Kim, Tae-Hyung

    2017-01-01

    In the field of regenerative medicine, stem cells are highly promising due to their innate ability to generate multiple types of cells that could replace/repair damaged parts of human organs and tissues. It has been reported that both in vitro and in vivo function/survival of stem cells could significantly be improved by utilizing functional materials such as biodegradable polymers, metal composites, nanopatterns and nanohybrid particles. Of various biocompatible materials available for use in stem cell-based therapy and research, carbon-based materials—including fullerenes graphene/graphene oxide and carbon nanotubes—have been found to possess unique physicochemical characteristics that contribute to the effective guidance of stem cell differentiation into specific lineages. In this review, we discuss a number of previous reports that investigated the use of carbon-based materials to control stem cell behavior, with a particular focus on their immense potential to guide the osteogenesis of mesenchymal stem cells (MSCs). We hope that this review will provide information on the full potential of using various carbon-based materials in stem cell-mediated regenerative therapy, particularly for bone regeneration and repair.

  15. STEM crisis or STEM surplus? Yes and yes.

    Science.gov (United States)

    Xue, Yi; Larson, Richard C

    2015-05-01

    The last decade has seen considerable concern regarding a shortage of science, technology, engineering, and mathematics (STEM) workers to meet the demands of the labor market. At the same time, many experts have presented evidence of a STEM worker surplus. A comprehensive literature review, in conjunction with employment statistics, newspaper articles, and our own interviews with company recruiters, reveals a significant heterogeneity in the STEM labor market: the academic sector is generally oversupplied, while the government sector and private industry have shortages in specific areas.

  16. Stem cells for tooth engineering

    Directory of Open Access Journals (Sweden)

    G Bluteau

    2008-07-01

    Full Text Available Tooth development results from sequential and reciprocal interactions between the oral epithelium and the underlying neural crest-derived mesenchyme. The generation of dental structures and/or entire teeth in the laboratory depends upon the manipulation of stem cells and requires a synergy of all cellular and molecular events that finally lead to the formation of tooth-specific hard tissues, dentin and enamel. Although mesenchymal stem cells from different origins have been extensively studied in their capacity to form dentin in vitro, information is not yet available concerning the use of epithelial stem cells. The odontogenic potential resides in the oral epithelium and thus epithelial stem cells are necessary for both the initiation of tooth formation and enamel matrix production. This review focuses on the different sources of stem cells that have been used for making teeth in vitro and their relative efficiency. Embryonic, post-natal or even adult stem cells were assessed and proved to possess an enormous regenerative potential, but their application in dental practice is still problematic and limited due to various parameters that are not yet under control such as the high risk of rejection, cell behaviour, long tooth eruption period, appropriate crown morphology and suitable colour. Nevertheless, the development of biological approaches for dental reconstruction using stem cells is promising and remains one of the greatest challenges in the dental field for the years to come.

  17. AVOCADO SEEDLINGS MULTIPLE STEMS PRODUCTION

    Directory of Open Access Journals (Sweden)

    MARCUS VINICIUS SANDOVAL PAIXÃO

    2016-01-01

    Full Text Available ABSTRACT This study aimed to evaluate the potential of multi-stems in avocado seeds according to their mass as well as the adventitious rooting of multi-stem budding with or without the use of auxin. The research was carried out at the Vegetation House of Federal Institute of Espírito Santo, Campus Santa Teresa -ES, with seeds of different masses: 100 g, in which each experimental unit was made of five seeds, distributed within five repetitions, under a completely randomized design. The seeds were put to germinate and the percentage number of emergence and multiple stems were evaluated. After 150 days, the following evaluations were carried out: survival of rooted cuttings; number of leaves; stem diameter; root length; root volume; root and shoot fresh mass; root and shoot dry mass; shoot height; absolute growth and shoot growth rate; shoot dry weight/root dry mass ratio; shoot height/stem diameter ratio; shoot height/root length and Dickson's quality index ratio. Avocado seeds with mass over 100 g and between 81-100 g presented higher percentage of multiple stems. Rods over 20 cm that were not treated with IBA (indole-3-butyric acid resulted on avocado plants of better quality. The use of IBA (2000 mg L-1 does not affect the rooting and growth of avocado's multi-stem plants.

  18. STEM Education Efforts in the Ares Projects

    Science.gov (United States)

    Doreswamy, Rajiv; Armstrong, Robert C.

    2010-01-01

    According to the National Science Foundation, of the more than 4 million first university degrees awarded in science and engineering in 2006, students in China earned about 21%, those in the European Union earned about 19%, and those in the United States earned about 11%. Statistics like these are of great interest to NASA's Ares Projects, which are responsible for building the rockets for the U.S. Constellation Program to send humans beyond low-Earth orbit. Science, technology, engineering, and mathematics students are essential for the long-term sustainability of any space program. Since the Projects creation, the Ares Outreach Team has used a variety of STEM-related media, methods, and materials to engage students, educators, and the general public in Constellation's mission. Like Project Apollo, the nation s exploration destinations and the vehicles used to get there can inspire students to learn more about STEM. Ares has been particularly active in public outreach to schools in Northern Alabama; on the Internet via outreach and grade-specific educational materials; and in more informal social media settings such as YouTube and Facebook. These combined efforts remain integral to America s space program, regardless of its future direction.

  19. Material Science

    Energy Technology Data Exchange (ETDEWEB)

    Won, Dong Yeon; Kim, Heung

    1987-08-15

    This book introduces material science, which includes key of a high-tech industry, new materials of dream like new metal material and semiconductor, classification of materials, microstructure of materials and characteristic. It mentions magic new materials such as shape memory alloy, fine ceramics, engineering fine ceramics, electronic ceramics, engineering plastic, glass, silicone conductor, optical fiber mixed materials and integrated circuit, challenge for new material and development of new materials.

  20. Material Science

    International Nuclear Information System (INIS)

    Won, Dong Yeon; Kim, Heung

    1987-08-01

    This book introduces material science, which includes key of a high-tech industry, new materials of dream like new metal material and semiconductor, classification of materials, microstructure of materials and characteristic. It mentions magic new materials such as shape memory alloy, fine ceramics, engineering fine ceramics, electronic ceramics, engineering plastic, glass, silicone conductor, optical fiber mixed materials and integrated circuit, challenge for new material and development of new materials.

  1. Stem cells in pharmaceutical biotechnology.

    Science.gov (United States)

    Zuba-Surma, Ewa K; Józkowicz, Alicja; Dulak, Józef

    2011-11-01

    Multiple populations of stem cells have been indicated to potentially participate in regeneration of injured organs. Especially, embryonic stem cells (ESC) and recently inducible pluripotent stem cells (iPS) receive a marked attention from scientists and clinicians for regenerative medicine because of their high proliferative and differentiation capacities. Despite that ESC and iPS cells are expected to give rise into multiple regenerative applications when their side effects are overcame during appropriate preparation procedures, in fact their most recent application of human ESC may, however, reside in their use as a tool in drug development and disease modeling. This review focuses on the applications of stem cells in pharmaceutical biotechnology. We discuss possible relevance of pluripotent cell stem populations in developing physiological models for any human tissue cell type useful for pharmacological, metabolic and toxicity evaluation necessary in the earliest steps of drug development. The present models applied for preclinical drug testing consist of primary cells or immortalized cell lines that show limitations in terms of accessibility or relevance to their in vivo counterparts. The availability of renewable human cells with functional similarities to their in vivo counterparts is the first landmark for a new generation of cell-based assays. We discuss the approaches for using stem cells as valuable physiological targets of drug activity which may increase the strength of target validation and efficacy potentially resulting in introducing new safer remedies into clinical trials and the marketplace. Moreover, we discuss the possible applications of stem cells for elucidating mechanisms of disease pathogenesis. The knowledge about the mechanisms governing the development and progression of multitude disorders which would come from the cellular models established based on stem cells, may give rise to new therapeutical strategies for such diseases. All

  2. Materials and material testing

    International Nuclear Information System (INIS)

    Joergens, H.

    1978-01-01

    A review based on 105 literature quotations is given on the latest state of development in the steel sector and in the field of non-ferrous metals and plastics. The works quoted also include, preparation, working, welding including simulation methods, improvement of weldability, material mechanics (explanation of defects mechanisms by means of fracture mechanics), defect causes (corrosion, erosion, hydrogen influence), mechanical-technological and non-destructive material testing. Examples from the field of reactor building are also given within there topics. (IHOE) [de

  3. Stem cells in endodontic therapy

    Directory of Open Access Journals (Sweden)

    Sita Rama Kumar M, Madhu Varma K, Kalyan Satish R, Manikya kumar Nanduri.R, Murali Krishnam Raju S, Mohan rao

    2014-11-01

    Full Text Available Stem cells have the remarkable potential to develop into many different cell types in the body. Serving as a sort of repair system for the body, they can theoretically divide without limit to replenish other cells as long as the person or animal is still alive. However, progress in stem cell biology and tissue engineering may present new options for replacing heavily damaged or lost teeth, or even individual tooth structures. The goal of this review is to discuss the potential impact of dental pulp stem cells on regenerative endodontics.

  4. Human stromal (mesenchymal) stem cells

    DEFF Research Database (Denmark)

    Aldahmash, Abdullah; Zaher, Walid; Al-Nbaheen, May

    2012-01-01

    Human stromal (mesenchymal) stem cells (hMSC) represent a group of non-hematopoietic stem cells present in the bone marrow stroma and the stroma of other organs including subcutaneous adipose tissue, placenta, and muscles. They exhibit the characteristics of somatic stem cells of self......-renewal and multi-lineage differentiation into mesoderm-type of cells, e.g., to osteoblasts, adipocytes, chondrocytes and possibly other cell types including hepatocytes and astrocytes. Due to their ease of culture and multipotentiality, hMSC are increasingly employed as a source for cells suitable for a number...

  5. Stem cells and respiratory diseases

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, Soraia Carvalho; Maron-Gutierrez, Tatiana; Garcia, Cristiane Sousa Nascimento Baez; Morales, Marcelo Marcos; Rocco, Patricia Rieken Macedo [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Biofisica Carlos Chagas Filho. Lab. de Investigacao]. E-mail: prmrocco@biof.ufrj.br

    2008-12-15

    Stem cells have a multitude of clinical implications in the lung. This article is a critical review that includes clinical and experimental studies of MedLine and SciElo database in the last 10 years, where we highlight the effects of stem cell therapy in acute respiratory distress syndrome or more chronic disorders such as lung fibrosis and emphysema. Although, many studies have shown the beneficial effects of stem cells in lung development, repair and remodeling; some important questions need to be answered to better understand the mechanisms that control cell division and differentiation, therefore enabling the use of cell therapy in human respiratory diseases. (author)

  6. Stem cells and respiratory diseases

    International Nuclear Information System (INIS)

    Abreu, Soraia Carvalho; Maron-Gutierrez, Tatiana; Garcia, Cristiane Sousa Nascimento Baez; Morales, Marcelo Marcos; Rocco, Patricia Rieken Macedo

    2008-01-01

    Stem cells have a multitude of clinical implications in the lung. This article is a critical review that includes clinical and experimental studies of MedLine and SciElo database in the last 10 years, where we highlight the effects of stem cell therapy in acute respiratory distress syndrome or more chronic disorders such as lung fibrosis and emphysema. Although, many studies have shown the beneficial effects of stem cells in lung development, repair and remodeling; some important questions need to be answered to better understand the mechanisms that control cell division and differentiation, therefore enabling the use of cell therapy in human respiratory diseases. (author)

  7. The Current Status of STEM Education Research

    Science.gov (United States)

    Brown, Josh

    2012-01-01

    This paper explores the current Science, Technology, Engineering and Mathematics (STEM) education research base through an analysis of articles from eight journals focused on the STEM disciplines. Analyzed are both practitioner and research publications to determine the current scope of STEM education research, where current STEM education…

  8. Integrating independent research into science curricula to foster STEM leadership

    Science.gov (United States)

    Queenan, Craig; Calabro, Alyssa; Becker, David

    2013-05-01

    Preparing students for college and future careers is one of the main goals of K-12 education, but current STEM teaching methods do not do enough to interest students and leave them prepared to enter into and succeed in STEM careers. While measures to implement unifying standards for science education across the country are aimed at ensuring that all students are taught the same material at each grade level, a shift in the way science is taught to is needed to complete the redesign of science education. The independent research model described here aligns with the new content standards and focuses on developing the principles of perspective, purpose, resources, collaboration, analysis, and presentation. These principles not only engage students in the classroom, but also leave students prepared to enter into science programs in college and succeed in leadership roles in the STEM workforce.

  9. Biobanking human embryonic stem cell lines: policy, ethics and efficiency.

    Science.gov (United States)

    Holm, Søren

    2015-12-01

    Stem cell banks curating and distributing human embryonic stem cells have been established in a number of countries and by a number of private institutions. This paper identifies and critically discusses a number of arguments that are used to justify the importance of such banks in policy discussions relating to their establishment or maintenance. It is argued (1) that 'ethical arguments' are often more important in the establishment phase and 'efficiency arguments' more important in the maintenance phase, and (2) that arguments relating to the interests of embryo and gamete donors are curiously absent from the particular stem cell banking policy discourse. This to some extent artificially isolates this discourse from the broader discussions about the flows of reproductive materials and tissues in modern society, and such isolation may lead to the interests of important actors being ignored in the policy making process.

  10. Stem cell dynamics in the hair follicle niche

    Science.gov (United States)

    Rompolas, Panteleimon; Greco, Valentina

    2014-01-01

    Hair follicles are skin appendages of the mammalian skin that have the ability to periodically and stereotypically regenerate in order to continuously produce new hair over our lifetime. The ability of the hair follicle to regenerate is due to the presence of stem cells that along with other cell populations and non-cellular components, including molecular signals and extracellular material, make up a niche microenvironment. Mounting evidence suggests that the niche is critical for regulating stem cell behavior and thus the process of regeneration. Here we review the literature concerning past and current studies that have utilized mouse genetic models, combined with other approaches to dissect the molecular and cellular composition of the hair follicle niche. We also discuss our current understanding of how stem cells operate within the niche during the process of tissue regeneration and the factors that regulate their behavior. PMID:24361866

  11. Expanding STEM opportunities through inclusive STEM-focused high schools.

    Science.gov (United States)

    Means, Barbara; Wang, Haiwen; Wei, Xin; Lynch, Sharon; Peters, Vanessa; Young, Viki; Allen, Carrie

    2017-09-01

    Inclusive STEM high schools (ISHSs) (where STEM is science, technology, engineering, and mathematics) admit students on the basis of interest rather than competitive examination. This study examines the central assumption behind these schools-that they provide students from subgroups underrepresented in STEM with experiences that equip them academically and attitudinally to enter and stay in the STEM pipeline. Hierarchical modeling was applied to data from student surveys and state longitudinal data records for 5113 students graduating from 39 ISHSs and 22 comprehensive high schools in North Carolina and Texas. Compared to peers from the same demographic group with similar Grade 8 achievement levels, underrepresented minority and female ISHS students in both states were more likely to undertake advanced STEM coursework. Hispanics in Texas and females in both states expressed more STEM career interest in Grade 12 if they attended an ISHS. Positive relationships between ISHS attendance and grade point average were found in the total sample and each subgroup in North Carolina. Positive ISHS advantages in terms of test scores for the total student sample were found for science in both states and for mathematics in Texas. For the various student subgroups, test score differences favored the ISHS samples but attained statistical significance only for African Americans' science achievement scores in the Texas study.

  12. A modified efficient method for dental pulp stem cell isolation

    Directory of Open Access Journals (Sweden)

    Maryam Raoof

    2014-01-01

    Full Text Available Background: Dental pulp stem cells can be used in regenerative endodontic therapy. The aim of this study was to introduce an efficient method for dental pulp stem cells isolation. Materials and Methods: In this in-vitro study, 60 extracted human third molars were split and pulp tissue was extracted. Dental pulp stem cells were isolated by the following three different methods: (1 digestion of pulp by collagenase/dispase enzyme and culture of the released cells; (2 outgrowth of the cells by culture of undigested pulp pieces; (3 digestion of pulp tissue pieces and fixing them. The cells were cultured in minimum essential medium alpha modification (αMEM medium supplemented with 20% fetal bovine serum(FBS in humid 37°C incubator with 5% CO 2 . The markers of stem cells were studied by reverse transcriptase polymerase chain reaction (PCR. The student t-test was used for comparing the means of independent groups. P <0.05 was considered as significant. Results: The results indicated that by the first method a few cell colonies with homogenous morphology were detectable after 4 days, while in the outgrowth method more time was needed (10-12 days to allow sufficient numbers of heterogeneous phenotype stem cells to migrate out of tissue. Interestingly, with the improved third method, we obtained stem cells successfully with about 60% efficiency after 2 days. The results of RT-PCR suggested the expression of Nanog, Oct-4, and Nucleostemin markers in the isolated cells from dental pulps. Conclusion: This study proposes a new method with high efficacy to obtain dental pulp stem cells in a short time.

  13. [Progress in stem cells and regenerative medicine].

    Science.gov (United States)

    Wang, Libin; Zhu, He; Hao, Jie; Zhou, Qi

    2015-06-01

    Stem cells have the ability to differentiate into all types of cells in the body and therefore have great application potential in regenerative medicine, in vitro disease modelling and drug screening. In recent years, stem cell technology has made great progress, and induced pluripotent stem cell technology revolutionizes the whole stem cell field. At the same time, stem cell research in our country has also achieved great progress and becomes an indispensable power in the worldwide stem cell research field. This review mainly focuses on the research progress in stem cells and regenerative medicine in our country since the advent of induced pluripotent stem cell technology, including induced pluripotent stem cells, transdifferentiation, haploid stem cells, and new gene editing tools.

  14. Stem cells: Concepts and prospects

    Indian Academy of Sciences (India)

    development exemplified by murine experiments motivated the ... from specific regions of the brain, cardiac stem cells from atrial ..... have also been shown to integrate and differentiate .... to vascular network structures in three dimensional.

  15. Stem Cells and Tissue Engineering

    CERN Document Server

    Pavlovic, Mirjana

    2013-01-01

    Stem cells are the building blocks for all other cells in an organism. The human body has about 200 different types of cells and any of those cells can be produced by a stem cell. This fact emphasizes the significance of stem cells in transplantational medicine, regenerative therapy and bioengineering. Whether embryonic or adult, these cells can be used for the successful treatment of a wide range of diseases that were not treatable before, such as osteogenesis imperfecta in children, different forms of leukemias, acute myocardial infarction, some neural damages and diseases, etc. Bioengineering, e.g. successful manipulation of these cells with multipotential capacity of differentiation toward appropriate patterns and precise quantity, are the prerequisites for successful outcome and treatment. By combining in vivo and in vitro techniques, it is now possible to manage the wide spectrum of tissue damages and organ diseases. Although the stem-cell therapy is not a response to all the questions, it provides more...

  16. Stem Cell Transplants (For Parents)

    Science.gov (United States)

    ... of Transplants Transplantation Recovery Coping Print en español Trasplantes de células madre Stem cells are cells in ... finding a match is called tissue typing (or HLA [human leukocyte antigen] typing). HLA is a protein ...

  17. Stem Cells in Regenerative Medicine

    OpenAIRE

    Sykova, Eva; Forostyak, Serhiy

    2013-01-01

    Background: A number of cardiovascular, neurological, musculoskeletal and other diseases have a limited capacity for repair and only a modest progress has been made in treatment of brain diseases. The discovery of stem cells has opened new possibilities for the treatment of these maladies, and cell therapy now stands at the cutting-edge of modern regenerative medicine and tissue engineering. Experimental data and the first clinical trials employing stem cells have shown their broad therapeuti...

  18. The Longitudinal STEM Identity Trajectories of Middle School Girls who Participated in a Single-Sex Informal STEM Education Program

    Science.gov (United States)

    Hughes, Roxanne

    2014-03-01

    This study examined the longitudinal effects of participation in an all-girls STEM summer camp on young women's interest in STEM fields and motivation to pursue these fields. The SciGirls camp has been in existence since 2006, with its goal of providing a safe space for young women to explore STEM careers and strengthen their interest in these careers. Over 166 middle school age girls have participated in the program since it began in 2006. Of those participants, 60 responded to at least one of the follow up surveys that are sent every three years - 2009 and 2012. The surveys attempt to determine participants' level of interest in STEM. The survey was qualitative in nature and asked open ended questions. Results indicated that the camp had a positive effect on participants' perceptions of scientists and their work. This study adds to the literature that looks at the longitudinal impacts of informal STEM educational programs that expose young women to female scientist role models and mentors. This study supports the research that claims that exposing young women at an early age to science role models can positively alter their perception of science careers which can eventually increase the number of women who pursue these careers. This increase is important at a time when men still outnumber women in many science and engineering fields. This study was funded in part by the National Science Foundation Division of Materials Research through DMR 0654118.

  19. Dental Stem Cell in Tooth Development and Advances of Adult Dental Stem Cell in Regenerative Therapies.

    Science.gov (United States)

    Tan, Jiali; Xu, Xin; Lin, Jiong; Fan, Li; Zheng, Yuting; Kuang, Wei

    2015-01-01

    Stem cell-based therapies are considered as a promising treatment for many clinical usage such as tooth regeneration, bone repairation, spinal cord injury, and so on. However, the ideal stem cell for stem cell-based therapy still remains to be elucidated. In the past decades, several types of stem cells have been isolated from teeth, including dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHED), periodontal ligament stem cells (PDLSCs), dental follicle progenitor stem cells (DFPCs) and stem cells from apical papilla (SCAP), which may be a good source for stem cell-based therapy in certain disease, especially when they origin from neural crest is considered. In this review, the specific characteristics and advantages of the adult dental stem cell population will be summarized and the molecular mechanisms of the differentiation of dental stem cell during tooth development will be also discussed.

  20. Influence of mechanical environment on the engineering of mineralized tissues using human dental pulp stem cells and silk fibroin scaffolds

    NARCIS (Netherlands)

    Woloszyk, A.; Holsten Dircksen, S.; Bostanci, N.; Müller, R.; Hofmann, S.; Mitsiadis, T.A.

    2015-01-01

    Teeth constitute a promising source of stem cells that can be used for tissue engineering and regenerative medicine purposes. Bone loss in the craniofacial complex due to pathological conditions and severe injuries could be treated with new materials combined with human dental pulp stem cells

  1. In vitro generation of motor neuron precursors from mouse embryonic stem cells using mesoporous nanoparticles

    DEFF Research Database (Denmark)

    Garcia-Bennett, Alfonso E; König, Niclas; Abrahamsson, Ninnie

    2014-01-01

    nanoparticles could be effective for stem cell differentiation in vitro. Materials & methods: We used a mouse embryonic stem cell line expressing green fluorescent protein under the promoter for the MN-specific gene Hb9 to visualize the level of MN differentiation. The differentiation of stem cells......Aim: Stem cell-derived motor neurons (MNs) are utilized to develop replacement strategies for spinal cord disorders. Differentiation of embryonic stem cells into MN precursors involves factors and their repeated administration. We investigated if delivery of factors loaded into mesoporous...... was evaluated by expression of MN-specific transcription factors monitored by quantitative real-time PCR reactions and immunocytochemistry. Results: Mesoporous nanoparticles have strong affiliation to the embryoid bodies, penetrate inside the embryoid bodies and come in contact with differentiating cells...

  2. Toward reliable and repeatable automated STEM-EDS metrology with high throughput

    Science.gov (United States)

    Zhong, Zhenxin; Donald, Jason; Dutrow, Gavin; Roller, Justin; Ugurlu, Ozan; Verheijen, Martin; Bidiuk, Oleksii

    2018-03-01

    New materials and designs in complex 3D architectures in logic and memory devices have raised complexity in S/TEM metrology. In this paper, we report about a newly developed, automated, scanning transmission electron microscopy (STEM) based, energy dispersive X-ray spectroscopy (STEM-EDS) metrology method that addresses these challenges. Different methodologies toward repeatable and efficient, automated STEM-EDS metrology with high throughput are presented: we introduce the best known auto-EDS acquisition and quantification methods for robust and reliable metrology and present how electron exposure dose impacts the EDS metrology reproducibility, either due to poor signalto-noise ratio (SNR) at low dose or due to sample modifications at high dose conditions. Finally, we discuss the limitations of the STEM-EDS metrology technique and propose strategies to optimize the process both in terms of throughput and metrology reliability.

  3. Matrix elasticity of void-forming hydrogels controls transplanted-stem-cell-mediated bone formation

    Science.gov (United States)

    Huebsch, Nathaniel; Lippens, Evi; Lee, Kangwon; Mehta, Manav; Koshy, Sandeep T.; Darnell, Max C.; Desai, Rajiv M.; Madl, Christopher M.; Xu, Maria; Zhao, Xuanhe; Chaudhuri, Ovijit; Verbeke, Catia; Kim, Woo Seob; Alim, Karen; Mammoto, Akiko; Ingber, Donald E.; Duda, Georg N.; Mooney, David J.

    2015-12-01

    The effectiveness of stem cell therapies has been hampered by cell death and limited control over fate. These problems can be partially circumvented by using macroporous biomaterials that improve the survival of transplanted stem cells and provide molecular cues to direct cell phenotype. Stem cell behaviour can also be controlled in vitro by manipulating the elasticity of both porous and non-porous materials, yet translation to therapeutic processes in vivo remains elusive. Here, by developing injectable, void-forming hydrogels that decouple pore formation from elasticity, we show that mesenchymal stem cell (MSC) osteogenesis in vitro, and cell deployment in vitro and in vivo, can be controlled by modifying, respectively, the hydrogel’s elastic modulus or its chemistry. When the hydrogels were used to transplant MSCs, the hydrogel’s elasticity regulated bone regeneration, with optimal bone formation at 60 kPa. Our findings show that biophysical cues can be harnessed to direct therapeutic stem cell behaviours in situ.

  4. Road for understanding cancer stem cells

    DEFF Research Database (Denmark)

    Serakinci, Nedime; Erzik, Can

    2007-01-01

    There is increasing evidence suggesting that stem cells are susceptive to carcinogenesis and, consequently, can be the origin of many cancers. Recently, the neoplastic potential of stem cells has been supported by many groups showing the existence of subpopulations with stem cell characteristics...... in tumor biopsies such as brain and breast. Evidence supporting the cancer stem cell hypothesis has gained impact due to progress in stem cell biology and development of new models to validate the self-renewal potential of stem cells. Recent evidence on the possible identification of cancer stem cells may...... offer an opportunity to use these cells as future therapeutic targets. Therefore, model systems in this field have become very important and useful. This review will focus on the state of knowledge on cancer stem cell research, including cell line models for cancer stem cells. The latter will, as models...

  5. STEM Summer Academy on the Navajo Reservation

    Science.gov (United States)

    Alexander, C. J.

    2012-12-01

    The US Rosetta Project is the NASA contribution to the International Rosetta Mission, an ESA cornerstone mission to comet Churyumov-Gerasimenko. While the project's outreach efforts span multi-media, and a variety of age and ethnic groups, a special emphasis has been made to find a way to provide meaningful outreach to the reservation communities. Because language preservation is an issue of urgent concern to the reservation communities, and because Rosetta, uniquely among NASA missions, has been named after the notion that keys to missing understanding of elements of the ancient past were found in the language on the original Rosetta stone, the US Rosetta Project has embarked upon outreach with a focus on STEM vocabulary in ancient US languages of the Navajo, Hopi, Ojibwe, and other tribal communities as the project expands. NASA image and science are used and described in the native language, alongside lay English and scientific English curriculum elements. Additionally, science (geology/chemistry/botany/physics) elements drawn from the reservation environment, including geomorphology, geochemistry, soil physics, are included and discussed in the native language as much as possible — with their analogs in other planetary environments (such as Mars). In this paper we will report on the most recent Summer Science Academy [2012], a four week summer course for middle school children, created in collaboration with teachers and administrators in the Chinle Unified School District. The concept of the Academy was initiated in 2011, and the first Academy was conducted shortly thereafter, in June 2011 with 14 children, 3 instructors, and a NASA teacher workshop. The community requested three topics: geology, astronomy, and botany. The 2012 Academy built on the curriculum already developed with more robust field trips, addressed to specific science topics, additional quantitative measurements and activities, with more written material for the cultural components from

  6. Turnover of circulating hematopoietic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Dorie, M J; Maloney, M A; Patt, H M

    1979-10-01

    Short-term parabiosis of male and female CBA/CaJ mice was used to investigate the turnover of circulating hematopoietic stem cells. The change and subsequent disappearance of donor stem cells were monitored by spleen colony assay and chromosome analysis of individual colonies. The results revealed an exponential disappearance of pluripotent stem cells from blood with a characteristic half time of 1.7 h. Blood-borne stem cells were shown to be equilibrated with a subpopulation of marrow stem cells exhibiting a disappearance half time of 9.5 h. Splenectomy did not change the apparent rate of stem cell removal from the blood.

  7. Images of women in STEM fields

    Directory of Open Access Journals (Sweden)

    S. Cho

    2009-09-01

    Full Text Available This study investigated how eighth-grade students perceived images of women in STEM and non-STEM careers. Thirty-six images were posted on-line; we measured five characteristics of each image. Forty students participated in the study. We found that there were significant differences in attractiveness, creativity, and intelligence between STEM and non-STEM images. There were no significant differences for good at her job and organization. In addition, there were no significant differences among STEM and non-STEM images of women of the same race.

  8. Stem cells: sources and therapies

    Directory of Open Access Journals (Sweden)

    Manuela Monti

    2012-01-01

    Full Text Available The historical, lexical and conceptual issues embedded in stem cell biology are reviewed from technical, ethical, philosophical, judicial, clinical, economic and biopolitical perspectives. The mechanisms assigning the simultaneous capacity to self-renew and to differentiate to stem cells (immortal template DNA and asymmetric division are evaluated in the light of the niche hypothesis for the stemness state. The induction of cell pluripotency and the different stem cells sources are presented (embryonic, adult and cord blood. We highlight the embryonic and adult stem cell properties and possible therapies while we emphasize the particular scientific and social values of cord blood donation to set up cord blood banks. The current scientific and legal frameworks of cord blood banks are reviewed at an international level as well as allogenic, dedicated and autologous donations. The expectations and the challenges in relation to present-day targeted diseases like diabetes mellitus type I, Parkinson's disease and myocardial infarction are evaluated in the light of the cellular therapies for regenerative medicine.

  9. Stem cells therapy for ALS.

    Science.gov (United States)

    Mazzini, Letizia; Vescovi, Angelo; Cantello, Roberto; Gelati, Maurizio; Vercelli, Alessandro

    2016-01-01

    Despite knowledge on the molecular basis of amyotrophic lateral sclerosis (ALS) having quickly progressed over the last few years, such discoveries have not yet translated into new therapeutics. With the advancement of stem cell technologies there is hope for stem cell therapeutics as novel treatments for ALS. We discuss in detail the therapeutic potential of different types of stem cells in preclinical and clinical works. Moreover, we address many open questions in clinical translation. SC therapy is a potentially promising new treatment for ALS and the need to better understand how to develop cell-based experimental treatments, and how to implement them in clinical trials, becomes more pressing. Mesenchymal stem cells and neural fetal stem cells have emerged as safe and potentially effective cell types, but there is a need to carry out appropriately designed experimental studies to verify their long-term safety and possibly efficacy. Moreover, the cost-benefit analysis of the results must take into account the quality of life of the patients as a major end point. It is our opinion that a multicenter international clinical program aime d at fine-tuning and coordinating transplantation procedures and protocols is mandatory.

  10. Optical materials

    International Nuclear Information System (INIS)

    Poker, D.B.; Ortiz, C.

    1989-01-01

    This book reports on: Diamond films, Synthesis of optical materials, Structure related optical properties, Radiation effects in optical materials, Characterization of optical materials, Deposition of optical thin films, and Optical fibers and waveguides

  11. Influence of students' STEM self-efficacy on STEM and physics career choice

    Science.gov (United States)

    Halim, Lilia; Rahman, Norshariani Abd; Ramli, Nor Aidillina Mohd; Mohtar, Lilia Ellany

    2018-01-01

    Interest towards STEM and STEM careers is declining worldwide. Among the STEM related careers, the physics discipline has been the most affected in terms of numbers and imbalance of gender. This study investigates the role of self-efficacy in STEM towards STEM careers and Physics career based on gender and types of school. Findings showed that there is a positive and significant correlation between students' STEM self-efficacy and interest towards all disciplines in STEM and Physics career. Boys showed high level of self-efficacy in engineering discipline while the girls' associate more with science. Students from boarding schools showed higher self-efficacy and interest towards STEM careers compared to students from public schools. An implication of the study is that self-efficacy and interest in STEM careers are enhanced through engagement with STEM activities in and outside of school. Emphasis should be given to the role of counselors in making STEM careers relevant to students.

  12. Adipogenic placenta-derived mesenchymal stem cells are not lineage restricted by withdrawing extrinsic factors: developing a novel visual angle in stem cell biology.

    Science.gov (United States)

    Hu, C; Cao, H; Pan, X; Li, J; He, J; Pan, Q; Xin, J; Yu, X; Li, J; Wang, Y; Zhu, D; Li, L

    2016-03-17

    Current evidence implies that differentiated bone marrow mesenchymal stem cells (BMMSCs) can act as progenitor cells and transdifferentiate across lineage boundaries. However, whether this unrestricted lineage has specificities depending on the stem cell type is unknown. Placental-derived mesenchymal stem cells (PDMSCs), an easily accessible and less invasive source, are extremely useful materials in current stem cell therapies. No studies have comprehensively analyzed the transition in morphology, surface antigens, metabolism and multilineage potency of differentiated PDMSCs after their dedifferentiation. In this study, we showed that after withdrawing extrinsic factors, adipogenic PDMSCs reverted to a primitive cell population and retained stem cell characteristics. The mitochondrial network during differentiation and dedifferentiation may serve as a marker of absent or acquired pluripotency in various stem cell models. The new population proliferated faster than unmanipulated PDMSCs and could be differentiated into adipocytes, osteocytes and hepatocytes. The cell adhesion molecules (CAMs) signaling pathway and extracellular matrix (ECM) components modulate cell behavior and enable the cells to proliferate or differentiate during the differentiation, dedifferentiation and redifferentiation processes in our study. These observations indicate that the dedifferentiated PDMSCs are distinguishable from the original PDMSCs and may serve as a novel source in stem cell biology and cell-based therapeutic strategies. Furthermore, whether PDMSCs differentiated into other lineages can be dedifferentiated to a primitive cell population needs to be investigated.

  13. Strategic Materials

    National Research Council Canada - National Science Library

    Buhler, Carl; Burke, Adrian; Davis, Kirk; Gerhard, Michelle; Heil, Valerie; Hulse, Richard; Kwong, Ralph; Mahoney, Michael; Moran, Scott; Peek, Michael

    2006-01-01

    Some materials possess greater value than others. Materials that provide essential support for the nation's economic viability or enable critical military capabilities warrant special attention in security studies...

  14. Report of the International Stem Cell Banking Initiative Workshop Activity: Current Hurdles and Progress in Seed-Stock Banking of Human Pluripotent Stem Cells.

    Science.gov (United States)

    Kim, Jung-Hyun; Kurtz, Andreas; Yuan, Bao-Zhu; Zeng, Fanyi; Lomax, Geoff; Loring, Jeanne F; Crook, Jeremy; Ju, Ji Hyeon; Clarke, Laura; Inamdar, Maneesha S; Pera, Martin; Firpo, Meri T; Sheldon, Michael; Rahman, Nafees; O'Shea, Orla; Pranke, Patricia; Zhou, Qi; Isasi, Rosario; Rungsiwiwut, Ruttachuk; Kawamata, Shin; Oh, Steve; Ludwig, Tenneille; Masui, Tohru; Novak, Thomas J; Takahashi, Tsuneo; Fujibuchi, Wataru; Koo, Soo Kyung; Stacey, Glyn N

    2017-11-01

    This article summarizes the recent activity of the International Stem Cell Banking Initiative (ISCBI) held at the California Institute for Regenerative Medicine (CIRM) in California (June 26, 2016) and the Korean National Institutes for Health in Korea (October 19-20, 2016). Through the workshops, ISCBI is endeavoring to support a new paradigm for human medicine using pluripotent stem cells (hPSC) for cell therapies. Priority considerations for ISCBI include ensuring the safety and efficacy of a final cell therapy product and quality assured source materials, such as stem cells and primary donor cells. To these ends, ISCBI aims to promote global harmonization on quality and safety control of stem cells for research and the development of starting materials for cell therapies, with regular workshops involving hPSC banking centers, biologists, and regulatory bodies. Here, we provide a brief overview of two such recent activities, with summaries of key issues raised. Stem Cells Translational Medicine 2017;6:1956-1962. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  15. TIBIAL PERIPROSTHETIC FRACTURE COMBINED WITH TIBIAL STEM STRESS FRACTURE FROM TOTAL KNEE ARTHROPLASTY

    OpenAIRE

    Fonseca, Fernando; Rebelo, Edgar; Completo, Antonio

    2011-01-01

    Total knee arthroplasty complications related to the prosthetic material are very rare, except for polyethylene wear. We report the case of a 58-year-old woman who came to the emergency service of our hospital with a periprosthetic tibial fracture (Mayo Clinic type I). Careful examination showed that this fracture was concomitantly associated with a tibial stem fatigue fracture. The prosthesis and the stem were sent to an independent biomechanics laboratory for evaluation. A finite-element CA...

  16. Human embryonic stem cells handbook

    Directory of Open Access Journals (Sweden)

    Carlo Alberto Redi

    2013-03-01

    Full Text Available After the Nobel prize in physiology or medicine was awarded jointly to Sir John Gurdon and Shinya Yamanaka for the discovery that mature cells can be reprogrammed to become pluripotent it became imperative to write down the review for a book entirely devoted to human embryonic stem cells (hES, those cells that are a urgent need for researchers, those cells that rekindle the ethical debates and finally, last but not least, those cells whose study paved the way to obtain induced pluripotent stem cells by the OSKC’s Yamanaka method (the OSKC acronim refers, for those not familiar with the topic, to the four stemness genes used to transfect somatic fibroblasts: Oct4, Sox2, Klf4 and c-Myc....

  17. Epigenetics in cancer stem cells.

    Science.gov (United States)

    Toh, Tan Boon; Lim, Jhin Jieh; Chow, Edward Kai-Hua

    2017-02-01

    Compelling evidence have demonstrated that bulk tumors can arise from a unique subset of cells commonly termed "cancer stem cells" that has been proposed to be a strong driving force of tumorigenesis and a key mechanism of therapeutic resistance. Recent advances in epigenomics have illuminated key mechanisms by which epigenetic regulation contribute to cancer progression. In this review, we present a discussion of how deregulation of various epigenetic pathways can contribute to cancer initiation and tumorigenesis, particularly with respect to maintenance and survival of cancer stem cells. This information, together with several promising clinical and preclinical trials of epigenetic modulating drugs, offer new possibilities for targeting cancer stem cells as well as improving cancer therapy overall.

  18. Generation of Induced Pluripotent Stem Cells from Mammalian Endangered Species.

    Science.gov (United States)

    Ben-Nun, Inbar Friedrich; Montague, Susanne C; Houck, Marlys L; Ryder, Oliver; Loring, Jeanne F

    2015-01-01

    For some highly endangered species there are too few reproductively capable animals to maintain adequate genetic diversity, and extraordinary measures are necessary to prevent their extinction. Cellular reprogramming is a means to capture the genomes of individual animals as induced pluripotent stem cells (iPSCs), which may eventually facilitate reintroduction of genetic material into breeding populations. Here, we describe a method for generating iPSCs from fibroblasts of mammalian endangered species.

  19. Nine Things to Know About Stem Cell Treatments

    Science.gov (United States)

    ... Search Toggle Nav Nine Things To Know About Stem Cell Treatments Home > Stem Cells and Medicine > Nine Things ... Know About Stem Cell Treatments Many clinics offering stem cell treatments make claims that are not supported by ...

  20. Legal implications of translational promises of unproven stem cell ...

    African Journals Online (AJOL)

    2015-08-02

    Aug 2, 2015 ... multipotent stem cells are haematopoietic stem cells (HSCs), which give rise ... include diseases such as arthritis, heart attacks, multiple sclerosis, diabetes ... regard to autologous stem cell therapy, where a patient's own stem.

  1. STEM Education is Missing This.......

    Science.gov (United States)

    Orr, Laura; Johnson, Milton; Miller, Alexandra; Rebull, Luisa M.

    2017-01-01

    STEM education gets a lot of attention in schools, media, politics, and funding. But while the acronym grows from STEM to STEAM to STREAM, we still see a lack of student participation in real science, using big data and building partnerships with professionals in the field, and real student growth in science achievement. After the NITARP experience, we believe that NITARP is a rich, demanding, and authentic experience for dedicated teachers and students that provides a caliber of learning that is hard, if not impossible, to achieve in the traditional classroom. This poster looks at what STEM still needs to be and become for it to be the driving force behind greater student involvement, interest, and increased academic performance in the sciences. We focus on our own experiences and that of our students; our different teaching backgrounds and school environments; and the effects we see on our students using traditional and new STEM education and participation in the NITARP program. We come from backgrounds and situations that range from urban to rural, middle to high school, wide socioeconomic variety, gender differences, as well as different exposures to STEM opportunities. We propose that traditional and current standards for STEM education are falling short of what is needed for students to truly experience, understand, and gain the skills to accurately apply and advance in science. Incoming and current science teachers at all levels are not provided with quality, realistic, or applicable preparation. NITARP is truly a STEM experience because it actually integrates the 4 fields and provides opportunities for students to experience the overlap of the 4 fields in an authentic way. The deep, long term exposure to authentic research and technology as well as opportunity to talk with working scientists in a variety of fields have a huge impact on the students and teachers alike. Exposure to programs and experiences like NITARP are needed to help drive and support STEM

  2. Stem cells: a plant biology perspective

    NARCIS (Netherlands)

    Scheres, B.J.G.

    2005-01-01

    A recent meeting at the Juan March Foundation in Madrid, Spain brought together plant biologists to discuss the characteristics of plant stem cells that are unique and those that are shared by stem cells from the animal kingdom

  3. FDA Warns About Stem Cell Therapies

    Science.gov (United States)

    ... Home For Consumers Consumer Updates FDA Warns About Stem Cell Therapies Share Tweet Linkedin Pin it More sharing ... see the boxed section below for more advice. Stem Cell Uses and FDA Regulation The FDA has the ...

  4. Multifaceted Interpretation of Colon Cancer Stem Cells.

    Science.gov (United States)

    Hatano, Yuichiro; Fukuda, Shinya; Hisamatsu, Kenji; Hirata, Akihiro; Hara, Akira; Tomita, Hiroyuki

    2017-07-05

    Colon cancer is one of the leading causes of cancer-related deaths worldwide, despite recent advances in clinical oncology. Accumulating evidence sheds light on the existence of cancer stem cells and their role in conferring therapeutic resistance. Cancer stem cells are a minor fraction of cancer cells, which enable tumor heterogeneity and initiate tumor formation. In addition, these cells are resistant to various cytotoxic factors. Therefore, elimination of cancer stem cells is difficult but essential to cure the malignant foci completely. Herein, we review the recent evidence for intestinal stem cells and colon cancer stem cells, methods to detect the tumor-initiating cells, and clinical significance of cancer stem cell markers. We also describe the emerging problems of cancer stem cell theory, including bidirectional conversion and intertumoral heterogeneity of stem cell phenotype.

  5. Stem Cell Transplant Patients and Fungal Infections

    Science.gov (United States)

    ... Foodborne, Waterborne, and Environmental Diseases Mycotic Diseases Branch Stem Cell Transplant Patients and Fungal Infections Recommend on Facebook ... Mold . Top of Page Preventing fungal infections in stem cell transplant patients Fungi are difficult to avoid because ...

  6. Blood-Forming Stem Cell Transplants

    Science.gov (United States)

    ... to Ask about Your Treatment Research Blood-Forming Stem Cell Transplants On This Page What are bone marrow ... Considering becoming a bone marrow or a blood stem cell donor? View this video on YouTube. Follow a ...

  7. Systems Biology and Stem Cell Pluripotency

    DEFF Research Database (Denmark)

    Mashayekhi, Kaveh; Hall, Vanessa Jane; Freude, Kristine

    2016-01-01

    Recent breakthroughs in stem cell biology have accelerated research in the area of regenerative medicine. Over the past years, it has become possible to derive patient-specific stem cells which can be used to generate different cell populations for potential cell therapy. Systems biological...... modeling of stem cell pluripotency and differentiation have largely been based on prior knowledge of signaling pathways, gene regulatory networks, and epigenetic factors. However, there is a great need to extend the complexity of the modeling and to integrate different types of data, which would further...... improve systems biology and its uses in the field. In this chapter, we first give a general background on stem cell biology and regenerative medicine. Stem cell potency is introduced together with the hierarchy of stem cells ranging from pluripotent embryonic stem cells (ESCs) and induced pluripotent stem...

  8. Stem cell therapy for inflammatory bowel disease

    NARCIS (Netherlands)

    Duijvestein, Marjolijn

    2012-01-01

    Hematopoietic stem cell transplantation (HSCT) and mesenchymal stromal (MSC) cell therapy are currently under investigation as novel therapies for inflammatory bowel diseases (IBD). Hematopoietic stem cells are thought to repopulate the immune system and reset the immunological response to luminal

  9. Molecular mechanisms of adult stem cell aging

    National Research Council Canada - National Science Library

    Rudolph, K. Lenhard

    2010-01-01

    "There is growing evidence that adult stem cells age. This process can result in alterations in the number and function of stem cells, leading to distinct phenotypic outcomes in different organ systems...

  10. First Steps Toward Improving DoD STEM Workforce Diversity: Response to the 2012 Department of Defense STEM Diversity Summit

    Science.gov (United States)

    2013-01-01

    higher Education Forum higher Ed STEM Model College Developed model of best practices for higher education retention programs Launch fall 2012... learning materials to students all over the world. Examples include a system called Open Class provided by Pearson, which facilitates open online ...available from www.rand.org as a public service of the RAND Corporation. CHILDREN AND FAMILIES EDUCATION AND THE ARTS ENERGY AND ENVIRONMENT HEALTH AND

  11. College Students' Conceptions of Stem Cells, Stem Cell Research, and Cloning

    Science.gov (United States)

    Concannon, James P.; Siegel, Marcelle A.; Halverson, Kristy; Freyermuth, Sharyn

    2010-01-01

    In this study, we examined 96 undergraduate non-science majors' conceptions of stem cells, stem cell research, and cloning. This study was performed at a large, Midwest, research extensive university. Participants in the study were asked to answer 23 questions relating to stem cells, stem cell research, and cloning in an on-line assessment before…

  12. Characterization and comparison of osteoblasts derived from mouse embryonic stem cells and induced pluripotent stem cells

    NARCIS (Netherlands)

    Ma, Ming San; Kannan, Vishnu; de Vries, Anneriek E; Czepiel, Marcin; Wesseling, Evelyn; Balasubramaniyan, Veerakumar; Kuijer, Roelof; Vissink, Arjan; Copray, Sjef; Raghoebar, Gerry

    New developments in stem cell biology offer alternatives for the reconstruction of critical-sized bone defects. One of these developments is the use of induced pluripotent stem (iPS) cells. These stem cells are similar to embryonic stem (ES) cells, but can be generated from adult somatic cells and

  13. STEM Learning through Engineering Design: Impact on Middle Secondary Students' Interest towards STEM

    Science.gov (United States)

    Shahali, Edy Hafizan Mohd; Halim, Lilia; Rasul, Mohamad Sattar; Osman, Kamisah; Zulkifeli, Mohd Afendi

    2017-01-01

    The purpose of this study was to identify students' changes of (i) interest toward STEM subjects and (ii) interest to pursuing STEM career after participating in non-formal integrated STEM education programme. The programme exposed students with integrated STEM education through project based learning involving the application of five phases…

  14. Culture of Mouse Neural Stem Cell Precursors

    OpenAIRE

    Currle, D. Spencer; Hu, Jia Sheng; Kolski-Andreaco, Aaron; Monuki, Edwin S.

    2007-01-01

    Primary neural stem cell cultures are useful for studying the mechanisms underlying central nervous system development. Stem cell research will increase our understanding of the nervous system and may allow us to develop treatments for currently incurable brain diseases and injuries. In addition, stem cells should be used for stem cell research aimed at the detailed study of mechanisms of neural differentiation and transdifferentiation and the genetic and environmental signals that direct the...

  15. Stem Cell Therapy for Erectile Dysfunction.

    Science.gov (United States)

    Matz, Ethan L; Terlecki, Ryan; Zhang, Yuanyuan; Jackson, John; Atala, Anthony

    2018-04-06

    The prevalence of erectile dysfunction (ED) is substantial and continues to rise. Current therapeutics for ED consist of oral medications, intracavernosal injections, vacuum erection devices, and penile implants. While such options may manage the disease state, none of these modalities, however, restore function. Stem cell therapy has been evaluated for erectile restoration in animal models. These cells have been derived from multiple tissues, have varied potential, and may function via local engraftment or paracrine signaling. Bone marrow-derived stem cells (BMSC) and adipose-derived stem cells (ASC) have both been used in these models with noteworthy effects. Herein, we will review the pathophysiology of ED, animal models, current and novel stem-cell based therapeutics, clinical trials and areas for future research. The relevant literature and contemporary data using keywords, "stem cells and erectile dysfunction" was reviewed. Examination of evidence supporting the association between erectile dysfunction and adipose derived stem cells, bone marrow derived stem cells, placental stem cells, urine stem cells and stem cell therapy respectively. Placental-derived stem cells and urine-derived stem cells possess many similar properties as BMSC and ASC, but the methods of acquisition are favorable. Human clinical trials have already demonstrated successful use of stem cells for improvement of erectile function. The future of stem cell research is constantly being evaluated, although, the evidence suggests a place for stem cells in erectile dysfunction therapeutics. Matz EL, Terlecki R, Zhang Y, et al. Stem Cell Therapy for Erectile Dysfunction. Sex Med Rev 2018;XX:XXX-XXX. Copyright © 2018 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

  16. [Genetic regulation of plant shoot stem cells].

    Science.gov (United States)

    Al'bert, E V; Ezhova, T A

    2013-02-01

    This article describes the main features of plant stem cells and summarizes the results of studies of the genetic control of stem cell maintenance in the apical meristem of the shoot. It is demonstrated that the WUS-CLV gene system plays a key role in the maintenance of shoot apical stem cells and the formation of adventitious buds and somatic embryos. Unconventional concepts of plant stem cells are considered.

  17. Living in a Materials World: Materials Science Engineering Professional Development for K-12 Educators

    Energy Technology Data Exchange (ETDEWEB)

    Anne Seifert; Louis Nadelson

    2011-06-01

    Advances in materials science are fundamental to technological developments and have broad societal impacs. For example, a cellular phone is composed of a polymer case, liquid crystal displays, LEDs, silicon chips, Ni-Cd batteries, resistors, capacitors, speakers, microphones all of which have required advances in materials science to be compacted into a phone which is typically smaller than a deck of cards. Like many technological developments, cellular phones have become a ubiquitous part of society, and yet most people know little about the materials science associated with their manufacture. The probable condition of constrained knowledge of materials science was the motivation for developing and offering a 20 hour fourday course called 'Living in a Materials World.' In addition, materials science provides a connection between our every day experiences and the work of scientists and engineers. The course was offered as part of a larger K-12 teacher professional development project and was a component of a week-long summer institute designed specifically for upper elementary and middle school teachers which included 20 hour content strands, and 12 hours of plenary sessions, planning, and collaborative sharing. The focus of the institute was on enhancing teacher content knowledge in STEM, their capacity for teaching using inquiry, their comfort and positive attitudes toward teaching STEM, their knowledge of how people learn, and strategies for integrating STEM throughout the curriculum. In addition to the summer institute the participating teachers were provided with a kit of about $300 worth of materials and equipment to use to implement the content they learned in their classrooms. As part of this professional development project the participants were required to design and implement 5 lesson plans with their students this fall and report on the results, as part of the continuing education course associated with the project. 'Living in a

  18. Stem cell transplantation for treating Duchenne muscular dystrophy

    Science.gov (United States)

    Yang, Xiaofeng

    2012-01-01

    OBJECTIVE: To identify global research trends in stem cell transplantation for treating Duchenne muscular dystrophy using a bibliometric analysis of Web of Science. DATA RETRIEVAL: We performed a bibliometric analysis of studies on stem cell transplantation for treating Duchenne muscular dystrophy from 2002 to 2011 retrieved from Web of Science. SELECTION CRITERIA: Inclusion criteria: (a) peer-reviewed published articles on stem cell transplantation for treating Duchenne muscular dystrophy indexed in Web of Science; (b) original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material, and news items; and (c) publication between 2002 and 2011. Exclusion criteria: (a) articles that required manual searching or telephone access; (b) documents that were not published in the public domain; and (c) corrected papers. MAIN OUTCOME MEASURES: (1) Annual publication output; (2) distribution according to subject areas; (3) distribution according to journals; (4) distribution according to country; (5) distribution according to institution; (6) distribution according to institution in China; (7) distribution according to institution that cooperated with Chinese institutions; (8) top-cited articles from 2002 to 2006; (9) top-cited articles from 2007 to 2011. RESULTS: A total of 318 publications on stem cell transplantation for treating Duchenne muscular dystrophy were retrieved from Web of Science from 2002 to 2011, of which almost half derived from American authors and institutes. The number of publications has gradually increased over the past 10 years. Most papers appeared in journals with a focus on gene and molecular research, such as Molecular Therapy, Neuromuscular Disorders, and PLoS One. The 10 most-cited papers from 2002 to 2006 were mostly about different kinds of stem cell transplantation for muscle regeneration, while the 10 most-cited papers from 2007 to 2011 were mostly about new techniques of stem cell transplantation

  19. Setting FIRES to Stem Cell Research

    Science.gov (United States)

    Miller, Roxanne Grietz

    2005-01-01

    The goal of this lesson is to present the basic scientific knowledge about stem cells, the promise of stem cell research to medicine, and the ethical considerations and arguments involved. One of the challenges of discussing stem cell research is that the field is constantly evolving and the most current information changes almost daily. Few…

  20. Organizing Organoids: Stem Cells Branch Out.

    Science.gov (United States)

    Davies, Jamie A

    2017-12-07

    In this issue of Cell Stem Cell, Taguchi and Nishinakamura (2017) describe a carefully optimized method for making a branch-competent ureteric bud, a tissue fundamental to kidney development, from mouse embryonic stem cells and human induced pluripotent stem cells. The work illuminates embryology and has important implications for making more realistic kidney organoids. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Advancing STEM Education: A 2020 Vision

    Science.gov (United States)

    Bybee, Rodger W.

    2010-01-01

    STEM (an acronym for science, technology, engineering and mathematics) had its origins in the 1990s at the National Science Foundation (NSF) and has been used as a generic label for any event, policy, program, or practice that involves one or several of the STEM disciplines. However, a recent survey on the "perception of STEM" found that most…

  2. 7 CFR 29.6039 - Stem rot.

    Science.gov (United States)

    2010-01-01

    ... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem resulting from bacterial action. Although stem rot results from bacterial action, it is inactive in cured tobacco...

  3. Enhancing the Psychology STEM Student Journey

    Science.gov (United States)

    Hill, Kimberley M.

    2017-01-01

    Psychology is a valuable Science, Technology, Engineering, and Mathematics (STEM) discipline, but one which could do far more at communicating its value to the wider public. This paper discusses how popular initiatives, such as "The University of Northampton's STEM Champions" programme, enhance psychology's STEM membership, while…

  4. 30 CFR 75.1322 - Stemming boreholes

    Science.gov (United States)

    2010-07-01

    ... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Explosives and Blasting § 75.1322 Stemming boreholes (a... deep shall be stemmed for at least half the depth of the borehole. (f) When blasting off the solid in... water stemming bag shall be within 1/4 of an inch of the diameter of the drill bit used to drill the...

  5. Involvement of plant stem cells or stem cell-like cells in dedifferentiation

    Directory of Open Access Journals (Sweden)

    Fangwei eJiang

    2015-11-01

    Full Text Available Dedifferentiation is the transformation of cells from a given differentiated state to a less differentiated or stem cell-like state. Stem cell-related genes play important roles in dedifferentiation, which exhibits similar histone modification and DNA methylation features to stem cell maintenance. Hence, stem cell-related factors possibly synergistically function to provide a specific niche beneficial to dedifferentiation. During callus formation in Arabidopsis petioles, cells adjacent to procambium cells (stem cell-like cells are dedifferentiated and survive more easily than other cell types. This finding indicates that stem cells or stem cell-like cells may influence the dedifferentiating niche. In this paper, we provide a brief overview of stem cell maintenance and dedifferentiation regulation. We also summarize current knowledge of genetic and epigenetic mechanisms underlying the balance between differentiation and dedifferentiation. Furthermore, we discuss the correlation of stem cells or stem cell-like cells with dedifferentiation.

  6. Anatomy of leaf and stem of Erythrina velutina

    Directory of Open Access Journals (Sweden)

    Márcia M. B. da Silva

    2013-04-01

    Full Text Available Erythrina velutina Willd., Fabaceae, known as "mulungu", is a tree of tropical regions, as northeastern Brazil. Its bark is used in folk medicine as tranquilizer, sedative and insomnia. This study aimed to characterize the stem and leaf anatomy and to provide subsidies to quality control of the plant drug due to its wide use in folk medicine as well as its differentiation from other species with the same popular name. Samples were collected at Cuité, in Paraíba State, Brazil, fixed in FAA50, semipermanent slides were made, following usual procedures in plant anatomy. The stem shows a cylindrical contour, covered by a uniseriate epidermis covered by a thickened cuticle. It shows claviform glandular and branched trichomes with uniseriate stalk. Secretory cavities are into the phloem. The leaf epidermis has branched and glandular trichomes and anisocytic and paracytic stomata, on both sides, with predominance of branched trichomes and stomata on abaxial surface. Secretory cavities in stem and leaf, types of trichomes and stomata, its location and distribution constitute diagnostic characters for this specie. The structural characterization of the stem and leaf allows its distinction from other ones of this genus, ensuring safety for commercial pharmacological uses, allowing certification of the authenticity of raw material.

  7. Anatomy of leaf and stem of Erythrina velutina

    Directory of Open Access Journals (Sweden)

    Márcia M. B. da Silva

    2013-02-01

    Full Text Available Erythrina velutina Willd., Fabaceae, known as "mulungu", is a tree of tropical regions, as northeastern Brazil. Its bark is used in folk medicine as tranquilizer, sedative and insomnia. This study aimed to characterize the stem and leaf anatomy and to provide subsidies to quality control of the plant drug due to its wide use in folk medicine as well as its differentiation from other species with the same popular name. Samples were collected at Cuité, in Paraíba State, Brazil, fixed in FAA50, semipermanent slides were made, following usual procedures in plant anatomy. The stem shows a cylindrical contour, covered by a uniseriate epidermis covered by a thickened cuticle. It shows claviform glandular and branched trichomes with uniseriate stalk. Secretory cavities are into the phloem. The leaf epidermis has branched and glandular trichomes and anisocytic and paracytic stomata, on both sides, with predominance of branched trichomes and stomata on abaxial surface. Secretory cavities in stem and leaf, types of trichomes and stomata, its location and distribution constitute diagnostic characters for this specie. The structural characterization of the stem and leaf allows its distinction from other ones of this genus, ensuring safety for commercial pharmacological uses, allowing certification of the authenticity of raw material.

  8. Periodontal tissue engineering strategies based on nonoral stem cells.

    Science.gov (United States)

    Requicha, João Filipe; Viegas, Carlos Alberto; Muñoz, Fernando; Reis, Rui Luís; Gomes, Manuela Estima

    2014-01-01

    Periodontal disease is an inflammatory disease which constitutes an important health problem in humans due to its enormous prevalence and life threatening implications on systemic health. Routine standard periodontal treatments include gingival flaps, root planning, application of growth/differentiation factors or filler materials and guided tissue regeneration. However, these treatments have come short on achieving regeneration ad integrum of the periodontium, mainly due to the presence of tissues from different embryonic origins and their complex interactions along the regenerative process. Tissue engineering (TE) aims to regenerate damaged tissue by providing the repair site with a suitable scaffold seeded with sufficient undifferentiated cells and, thus, constitutes a valuable alternative to current therapies for the treatment of periodontal defects. Stem cells from oral and dental origin are known to have potential to regenerate these tissues. Nevertheless, harvesting cells from these sites implies a significant local tissue morbidity and low cell yield, as compared to other anatomical sources of adult multipotent stem cells. This manuscript reviews studies describing the use of non-oral stem cells in tissue engineering strategies, highlighting the importance and potential of these alternative stem cells sources in the development of advanced therapies for periodontal regeneration. Copyright © 2013 Wiley Periodicals, Inc.

  9. OCT4 and SOX2 are reliable markers in detecting stem cells in odontogenic lesions

    Directory of Open Access Journals (Sweden)

    Abhishek Banerjee

    2016-01-01

    Full Text Available Context (Background: Stem cells are a unique subpopulation of cells in the human body with a capacity to initiate differentiation into various cell lines. Tumor stem cells (TSCs are a unique subpopulation of cells that possess the ability to initiate a neoplasm and sustain self-renewal. Epithelial stem cell (ESC markers such as octamer-binding transcription factor 4 (OCT4 and sex-determining region Y (SRY-box 2 (SOX2 are capable of identifying these stem cells expressed during the early stages of tooth development. Aims: To detect the expression of the stem cell markers OCT4 and SOX2 in the normal odontogenic tissues and the odontogenic cysts and tumors. Materials and Methods: Paraffin sections of follicular tissue, radicular cyst, dentigerous cyst, odontogenic keratocyst, ameloblastoma, adenomatoid odontogenic tumor, and ameloblastic carcinoma were obtained from the archives. The sections were subjected to immunohistochemical assay by the use of mouse monoclonal antibodies to OCT4 and SOX2. Statistical Analysis: The results were evaluated by descriptive analysis. Results: The results show the presence of stem cells in the normal and lesional tissues with these stem cell identifying markers. SOX2 was found to be more consistent and reliable in the detection of stem cells. Conclusion: The stem cell expressions are maintained in the tumor transformation of tissue and probably suggest that there is no phenotypic change of stem cells in progression from normal embryonic state to its tumor component. The quantification and localization reveals interesting trends that indicate the probable role of the cells in the pathogenesis of the lesions.

  10. Going beyond Fun in STEM

    Science.gov (United States)

    Pittinsky, Todd L.; Diamante, Nicole

    2015-01-01

    The United States education system must improve its ability to produce scientists, engineers, and programmers. Despite numerous national, state, and local efforts to make the study of STEM (science, technology, engineering, and mathematics) subjects more fun in K-12, initial interest in those subjects drops off precipitously in middle and later…

  11. Cyberinfrastructure for Undergraduate STEM Education

    Science.gov (United States)

    Swaid, Samar

    2013-01-01

    Cyberinfrastructure (CI) is a term that usually appears in scientific research, but rarely to be noticed as a scientific education tool. In this paper, I describe a transformative Cyberinfrastructure-based strategy to improve Science, Technology, Engineering and Mathematics (STEM) education at one of the historically black colleges. This strategy…

  12. Stem cells and regenerative medicine

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva

    2005-01-01

    Roč. 3, - (2005), s. 45-46 ISSN 1214-021X. [Cells VI - Biological Days /18./. 24.10.2005-26.10.2005, České Budějovice] R&D Projects: GA MŠk(CZ) 1M0538 Institutional research plan: CEZ:AV0Z5039906 Keywords : stem cells Subject RIV: FH - Neurology

  13. Plasticity of spermatogonial stem cells

    Directory of Open Access Journals (Sweden)

    Paul S Cooke

    2015-06-01

    Full Text Available There have been significant breakthroughs over the past decade in the development and use of pluripotent stem cells as a potential source of cells for applications in regenerative medicine. It is likely that this methodology will begin to play an important role in human clinical medicine in the years to come. This review describes the plasticity of one type of pluripotent cell, spermatogonial stem cells (SSCs, and their potential therapeutic applications in regenerative medicine and male infertility. Normally, SSCs give rise to sperm when in the testis. However, both human and murine SSCs can give rise to cells with embryonic stem (ES cell-like characteristics that can be directed to differentiate into tissues of all three embryonic germ layers when placed in an appropriate inductive microenvironment, which is in contrast to other postnatal stem cells. Previous studies have reported that SSCs expressed an intermediate pluripotent phenotype before differentiating into a specific cell type and that extended culture was necessary for this to occur. However, recent studies from our group using a tissue recombination model demonstrated that SSCs differentiated rapidly into another tissue, in this case, prostatic epithelium, without expression of pluripotent ES cell markers before differentiation. These results suggest that SSCs are capable of directly differentiating into other cell types without going through an intermediate ES cell-like stage. Because SSCs do not require reprogramming to achieve a pluripotent state, they are an attractive source of pluripotent cells for use in regenerative medicine.

  14. STEM Equality and Diversity Toolkit

    Science.gov (United States)

    Collins, Jill

    2011-01-01

    In 2008, the Centre for Science Education at Sheffield Hallam University teamed up with VT Enterprise (now Babcock International) in their submission of a successful bid to deliver the national STEM (Science, Technology, Engineering and Maths) Subject Choice and Careers Project. An integral part of the bid was the promotion of equality and…

  15. Stem Cells in Regenerative Medicine

    Czech Academy of Sciences Publication Activity Database

    Syková, Eva; Forostyak, Serhiy

    2013-01-01

    Roč. 22, č. 2 (2013), s. 87-92 ISSN 0898-5901 R&D Projects: GA ČR(CZ) GAP304/11/0189; GA ČR(CZ) GBP304/12/G069 Institutional research plan: CEZ:AV0Z50390703 Institutional support: RVO:68378041 Keywords : cell therapy * stem cells * clinical study Subject RIV: FH - Neurology

  16. Adipose-Derived Stem Cells

    NARCIS (Netherlands)

    Gathier, WA; Türktas, Z; Duckers, HJ

    2015-01-01

    Until recently bone marrow was perceived to be the only significant reservoir of stem cells in the body. However, it is now recognized that there are other and perhaps even more abundant sources, which include adipose tissue. Subcutaneous fat is readily available in most patients, and can easily be

  17. The spermatogonial stem cell niche

    NARCIS (Netherlands)

    de Rooij, Dirk G.

    2009-01-01

    Spermatogonial stem cells (SSCs; A(s) spermatogonia) and their direct descendants (A(pr) and A(al) spermatogonia) are preferentially located in those areas of the seminiferous tubules that border on the interstitial tissue. Fewer of these cells are present in tubule areas directly bordering on

  18. Bioinspiring an Interest in STEM

    Science.gov (United States)

    Laut, Jeffrey; Bartolini, Tiziana; Porfiri, Maurizio

    2015-01-01

    Attracting K-12 students to pursue careers in science, technology, engineering, and mathematics (STEM) is viewed as a critical element for benefiting both the economy and society. This paper describes an outreach program, conducted in a Brooklyn, New York, USA, public middle school, aimed at educating students in mechatronics, biology, and…

  19. Stem cells in dentistry: A study regarding awareness of stem cells among dental professionals

    OpenAIRE

    Parita K Chitroda; Girish Katti; Nikhat M Attar; Syed Shahbaz; G Sreenivasarao; Ambika Patil

    2017-01-01

    Background: Dental stem cell, a type of adult stem cell, exhibits multipotent differentiation capacity and is drawing worldwide attention because of its numerous applications. The advances in applications of dental stem cells seem to be unsurpassed in the near future, for which specialized skills and knowledge in this arena are of prime significance. Hence, there is a need to acquire more knowledge about dental stem cells to obtain maximum benefits from it in the coming years. Dental stem cel...

  20. Materials Chemistry

    CERN Document Server

    Fahlman, Bradley D

    2011-01-01

    The 2nd edition of Materials Chemistry builds on the strengths that were recognized by a 2008 Textbook Excellence Award from the Text and Academic Authors Association (TAA). Materials Chemistry addresses inorganic-, organic-, and nano-based materials from a structure vs. property treatment, providing a suitable breadth and depth coverage of the rapidly evolving materials field. The 2nd edition continues to offer innovative coverage and practical perspective throughout. After briefly defining materials chemistry and its history, seven chapters discuss solid-state chemistry, metals, semiconducting materials, organic "soft" materials, nanomaterials, and materials characterization. All chapters have been thoroughly updated and expanded with, for example, new sections on ‘soft lithographic’ patterning, ‘click chemistry’ polymerization, nanotoxicity, graphene, as well as many biomaterials applications. The polymer and ‘soft’ materials chapter represents the largest expansion for the 2nd edition. Each ch...

  1. Extinction models for cancer stem cell therapy

    Science.gov (United States)

    Sehl, Mary; Zhou, Hua; Sinsheimer, Janet S.; Lange, Kenneth L.

    2012-01-01

    Cells with stem cell-like properties are now viewed as initiating and sustaining many cancers. This suggests that cancer can be cured by driving these cancer stem cells to extinction. The problem with this strategy is that ordinary stem cells are apt to be killed in the process. This paper sets bounds on the killing differential (difference between death rates of cancer stem cells and normal stem cells) that must exist for the survival of an adequate number of normal stem cells. Our main tools are birth–death Markov chains in continuous time. In this framework, we investigate the extinction times of cancer stem cells and normal stem cells. Application of extreme value theory from mathematical statistics yields an accurate asymptotic distribution and corresponding moments for both extinction times. We compare these distributions for the two cell populations as a function of the killing rates. Perhaps a more telling comparison involves the number of normal stem cells NH at the extinction time of the cancer stem cells. Conditioning on the asymptotic time to extinction of the cancer stem cells allows us to calculate the asymptotic mean and variance of NH. The full distribution of NH can be retrieved by the finite Fourier transform and, in some parameter regimes, by an eigenfunction expansion. Finally, we discuss the impact of quiescence (the resting state) on stem cell dynamics. Quiescence can act as a sanctuary for cancer stem cells and imperils the proposed therapy. We approach the complication of quiescence via multitype branching process models and stochastic simulation. Improvements to the τ-leaping method of stochastic simulation make it a versatile tool in this context. We conclude that the proposed therapy must target quiescent cancer stem cells as well as actively dividing cancer stem cells. The current cancer models demonstrate the virtue of attacking the same quantitative questions from a variety of modeling, mathematical, and computational perspectives

  2. The Effect of STEM Learning through the Project of Designing Boat Model toward Student STEM Literacy

    Science.gov (United States)

    Tati, T.; Firman, H.; Riandi, R.

    2017-09-01

    STEM Learning focusses on development of STEM-literate society, the research about implementation of STEM learning to develope students’ STEM literacy is still limited. This study is aimed to examine the effect of implementation STEM learning through the project of designing boat model on students STEM literacy in energy topic. The method of this study was a quasi-experiment with non-randomized pretest-posttest control group design. There were two classes involved, the experiment class used Project Based Learning with STEM approach and control class used Project-Based Learning without STEM approach. A STEM Literacy test instrument was developed to measure students STEM literacy which consists of science literacy, mathematics literacy, and technology-engineering literacy. The analysis showed that there were significant differences on improvement science literacy, mathematics technology-engineering between experiment class and control class with effect size more than 0.8 (large effect). The difference of improvement of STEM literacy between experiment class and control class is caused by the existence of design engineering activity which required students to apply the knowledge from every field of STEM. The challenge that was faced in STEM learning through design engineering activity was how to give the students practice to integrate STEM field in solving the problems. In additional, most of the students gave positive response toward implementation of STEM learning through design boat model project.

  3. Adipose Stem Cell Coating of Biomimetic β-TCP Macrospheres by Use of Laboratory Centrifuge.

    Science.gov (United States)

    Chou, Joshua; Green, David W; Singh, Krishneel; Hao, Jia; Ben-Nissan, Besim; Milthorpe, Bruce

    2013-02-01

    Biomimetic materials such as coral exoskeletons possess unique architectural structures with a uniform and interconnected porous network that can be beneficial as a scaffold material. In addition, these marine structures can be hydrothermally converted to calcium phosphates, while retaining the original structural properties. The ability of biomaterials to stimulate the local microenvironment is one of the main focuses in tissue engineering, and directly coating the scaffold with stem cells facilitates future potential applications in therapeutics and regenerative medicine. In this article we describe a new and simple method that uses a laboratory centrifuge to coat hydrothermally derived beta-tricalcium phosphate macrospheres from coral exoskeleton with stem cells. In this research the optimal seeding duration and speed were determined to be 1 min and 700 g. Scanning electron micrographs showed complete surface coverage by stem cells within 7 days of seeding. This study constitutes an important step toward achieving functional tissue-engineered implants by increasing our understanding of the influence of dynamic parameters on the efficiency and distribution of stem cell attachment to biomimetic materials and how stem cells interact with biomimetic materials.

  4. New Advanced Technologies in Stem Cell Therapy

    Science.gov (United States)

    2014-11-01

    James, J. N. Zara , M. Corselli et al., “An abundant perivascular source of stem cells for bone tissue engineering,” Stem Cells Translational Medicine...vol. 1, no. 9, pp. 673–684, 2012. [89] A.W. James, J. N. Zara , X. Zhang et al., “Perivascular stem cells: a prospectively purified mesenchymal stem...1, pp. 54–63, 2009. [176] A. Askarinam, A. W. James, J. N. Zara et al., “Human perivas- cular stem cells show enhanced osteogenesis and

  5. Exploring Student Engagement in STEM Education: An Examination of STEM Schools, STEM Programs, and Traditional Schools

    Science.gov (United States)

    Franco, M. Suzanne; Patel, Nimisha H.

    2017-01-01

    High school students' perceptions and experiences regarding student engagement were investigated using 32 focus group sessions across 4 different types of STEM education settings in 2 metropolitan areas in the Midwest. Students' understandings and experiences related to student engagement were reflected via 5 categories: students' thinking of…

  6. Dental pulp stem cells in regenerative dentistry.

    Science.gov (United States)

    Casagrande, Luciano; Cordeiro, Mabel M; Nör, Silvia A; Nör, Jacques E

    2011-01-01

    Stem cells constitute the source of differentiated cells for the generation of tissues during development, and for regeneration of tissues that are diseased or injured postnatally. In recent years, stem cell research has grown exponentially owing to the recognition that stem cell-based therapies have the potential to improve the life of patients with conditions that span from Alzheimer's disease to cardiac ischemia to bone or tooth loss. Growing evidence demonstrates that stem cells are primarily found in niches and that certain tissues contain more stem cells than others. Among these tissues, the dental pulp is considered a rich source of mesenchymal stem cells that are suitable for tissue engineering applications. It is known that dental pulp stem cells have the potential to differentiate into several cell types, including odontoblasts, neural progenitors, osteoblasts, chondrocytes, and adipocytes. The dental pulp stem cells are highly proliferative. This characteristic facilitates ex vivo expansion and enhances the translational potential of these cells. Notably, the dental pulp is arguably the most accessible source of postnatal stem cells. Collectively, the multipotency, high proliferation rates, and accessibility make the dental pulp an attractive source of mesenchymal stem cells for tissue regeneration. This review discusses fundamental concepts of stem cell biology and tissue engineering within the context of regenerative dentistry.

  7. Methods for Stem Cell Production and Therapy

    Science.gov (United States)

    Valluri, Jagan V. (Inventor); Claudio, Pier Paolo (Inventor)

    2015-01-01

    The present invention relates to methods for rapidly expanding a stem cell population with or without culture supplements in simulated microgravity conditions. The present invention relates to methods for rapidly increasing the life span of stem cell populations without culture supplements in simulated microgravity conditions. The present invention also relates to methods for increasing the sensitivity of cancer stem cells to chemotherapeutic agents by culturing the cancer stem cells under microgravity conditions and in the presence of omega-3 fatty acids. The methods of the present invention can also be used to proliferate cancer cells by culturing them in the presence of omega-3 fatty acids. The present invention also relates to methods for testing the sensitivity of cancer cells and cancer stem cells to chemotherapeutic agents by culturing the cancer cells and cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce tissue for use in transplantation by culturing stem cells or cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce cellular factors and growth factors by culturing stem cells or cancer stem cells under microgravity conditions. The methods of the present invention can also be used to produce cellular factors and growth factors to promote differentiation of cancer stem cells under microgravity conditions.

  8. Challenges for heart disease stem cell therapy

    Directory of Open Access Journals (Sweden)

    Hoover-Plow J

    2012-02-01

    Full Text Available Jane Hoover-Plow, Yanqing GongDepartments of Cardiovascular Medicine and Molecular Cardiology, Joseph J Jacobs Center for Thrombosis and Vascular Biology, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USAAbstract: Cardiovascular diseases (CVDs are the leading cause of death worldwide. The use of stem cells to improve recovery of the injured heart after myocardial infarction (MI is an important emerging therapeutic strategy. However, recent reviews of clinical trials of stem cell therapy for MI and ischemic heart disease recovery report that less than half of the trials found only small improvements in cardiac function. In clinical trials, bone marrow, peripheral blood, or umbilical cord blood cells were used as the source of stem cells delivered by intracoronary infusion. Some trials administered only a stem cell mobilizing agent that recruits endogenous sources of stem cells. Important challenges to improve the effectiveness of stem cell therapy for CVD include: (1 improved identification, recruitment, and expansion of autologous stem cells; (2 identification of mobilizing and homing agents that increase recruitment; and (3 development of strategies to improve stem cell survival and engraftment of both endogenous and exogenous sources of stem cells. This review is an overview of stem cell therapy for CVD and discusses the challenges these three areas present for maximum optimization of the efficacy of stem cell therapy for heart disease, and new strategies in progress.Keywords: mobilization, expansion, homing, survival, engraftment

  9. Cancer stem cells and differentiation therapy.

    Science.gov (United States)

    Jin, Xiong; Jin, Xun; Kim, Hyunggee

    2017-10-01

    Cancer stem cells can generate tumors from only a small number of cells, whereas differentiated cancer cells cannot. The prominent feature of cancer stem cells is its ability to self-renew and differentiate into multiple types of cancer cells. Cancer stem cells have several distinct tumorigenic abilities, including stem cell signal transduction, tumorigenicity, metastasis, and resistance to anticancer drugs, which are regulated by genetic or epigenetic changes. Like normal adult stem cells involved in various developmental processes and tissue homeostasis, cancer stem cells maintain their self-renewal capacity by activating multiple stem cell signaling pathways and inhibiting differentiation signaling pathways during cancer initiation and progression. Recently, many studies have focused on targeting cancer stem cells to eradicate malignancies by regulating stem cell signaling pathways, and products of some of these strategies are in preclinical and clinical trials. In this review, we describe the crucial features of cancer stem cells related to tumor relapse and drug resistance, as well as the new therapeutic strategy to target cancer stem cells named "differentiation therapy."

  10. Redox regulation of plant stem cell fate.

    Science.gov (United States)

    Zeng, Jian; Dong, Zhicheng; Wu, Haijun; Tian, Zhaoxia; Zhao, Zhong

    2017-10-02

    Despite the importance of stem cells in plant and animal development, the common mechanisms of stem cell maintenance in both systems have remained elusive. Recently, the importance of hydrogen peroxide (H 2 O 2 ) signaling in priming stem cell differentiation has been extensively studied in animals. Here, we show that different forms of reactive oxygen species (ROS) have antagonistic roles in plant stem cell regulation, which were established by distinct spatiotemporal patterns of ROS-metabolizing enzymes. The superoxide anion (O2·-) is markedly enriched in stem cells to activate WUSCHEL and maintain stemness, whereas H 2 O 2 is more abundant in the differentiating peripheral zone to promote stem cell differentiation. Moreover, H 2 O 2 negatively regulates O2·- biosynthesis in stem cells, and increasing H 2 O 2 levels or scavenging O2·- leads to the termination of stem cells. Our results provide a mechanistic framework for ROS-mediated control of plant stem cell fate and demonstrate that the balance between O2·- and H 2 O 2 is key to stem cell maintenance and differentiation. © 2017 The Authors.

  11. Contrast Materials

    Science.gov (United States)

    ... is mixed with water before administration liquid paste tablet When iodine-based and barium-sulfate contrast materials ... for patients with kidney failure or allergies to MRI and/or computed tomography (CT) contrast material. Microbubble ...

  12. Stem cells and repair of lung injuries

    Directory of Open Access Journals (Sweden)

    Randell Scott H

    2004-07-01

    Full Text Available Abstract Fueled by the promise of regenerative medicine, currently there is unprecedented interest in stem cells. Furthermore, there have been revolutionary, but somewhat controversial, advances in our understanding of stem cell biology. Stem cells likely play key roles in the repair of diverse lung injuries. However, due to very low rates of cellular proliferation in vivo in the normal steady state, cellular and architectural complexity of the respiratory tract, and the lack of an intensive research effort, lung stem cells remain poorly understood compared to those in other major organ systems. In the present review, we concisely explore the conceptual framework of stem cell biology and recent advances pertinent to the lungs. We illustrate lung diseases in which manipulation of stem cells may be physiologically significant and highlight the challenges facing stem cell-related therapy in the lung.

  13. Recent advances in hematopoietic stem cell biology

    DEFF Research Database (Denmark)

    Bonde, Jesper; Hess, David A; Nolta, Jan A

    2004-01-01

    PURPOSE OF REVIEW: Exciting advances have been made in the field of hematopoietic stem cell biology during the past year. This review summarizes recent progress in the identification, culture, and in vivo tracking of hematopoietic stem cells. RECENT FINDINGS: The roles of Wnt and Notch proteins...... in regulating stem cell renewal in the microenvironment, and how these molecules can be exploited in ex vivo stem cell culture, are reviewed. The importance of identification of stem cells using functional as well as phenotypic markers is discussed. The novel field of nanotechnology is then discussed...... in the context of stem cell tracking in vivo. This review concludes with a section on the unexpected potential of bone marrow-derived stem cells to contribute to the repair of damaged tissues. The contribution of cell fusion to explain the latter phenomenon is discussed. SUMMARY: Because of exciting discoveries...

  14. Nuclear Mechanics and Stem Cell Differentiation.

    Science.gov (United States)

    Mao, Xinjian; Gavara, Nuria; Song, Guanbin

    2015-12-01

    Stem cells are characterized by their self-renewal and multi-lineage differentiation potential. Stem cell differentiation is a prerequisite for the application of stem cells in regenerative medicine and clinical therapy. In addition to chemical stimulation, mechanical cues play a significant role in regulating stem cell differentiation. The integrity of mechanical sensors is necessary for the ability of cells to respond to mechanical signals. The nucleus, the largest and stiffest cellular organelle, interacts with the cytoskeleton as a key mediator of cell mechanics. Nuclear mechanics are involved in the complicated interactions of lamins, chromatin and nucleoskeleton-related proteins. Thus, stem cell differentiation is intimately associated with nuclear mechanics due to its indispensable role in mechanotransduction and mechanical response. This paper reviews several main contributions of nuclear mechanics, highlights the hallmarks of the nuclear mechanics of stem cells, and provides insight into the relationship between nuclear mechanics and stem cell differentiation, which may guide clinical applications in the future.

  15. Stem cell facelift: between reality and fiction.

    Science.gov (United States)

    Atiyeh, Bishara S; Ibrahim, Amir E; Saad, Dibo A

    2013-03-01

    Stem cells are "big business" throughout medical technology, and their potential application in cosmetic procedures is no exception. One of the latest nonsurgical facial treatments (and new catchphrases) in plastic surgery is the "stem cell facelift." It is evident from the currently available scientific literature that the use of stem cell therapy for facial rejuvenation is limited to the theoretical induction of skin tightening and can in no way be equated to a facelift. In fact, what is advertised and promoted as a new and original technique of stem cell facelifting is mostly stem cell-enriched lipofilling. Despite encouraging data suggesting that adult stem cells hold promise for future applications, the data from clinical evidence available today do not substantiate the marketing and promotional claims being made to patients. To claim that the "stem cell facelift" is a complete facial rejuvenation procedure surgery is unethical.

  16. Effects of phyllotaxy on biomechanical properties of stems of Cercis occidentalis (Fabaceae).

    Science.gov (United States)

    Caringella, Marissa A; Bergman, Brett A; Stanfield, Ryan C; Ewers, Madeleine M; Bobich, Edward G; Ewers, Frank W

    2014-01-01

    Phyllotaxy, the arrangement of leaves on a stem, may impact the mechanical properties of woody stems several years after the leaves have been shed. We explored mechanical properties of a plant with alternate distichous phyllotaxy, with a row of leaves produced on each side of the stem, to determine whether the nodes behave as spring-like joints. Flexural stiffness of 1 cm diameter woody stems was measured in four directions with an Instron mechanical testing system; the xylem of the stems was then cut into node (former leaf junction) and nonnode segments for measurement of xylem density. Stems had 20% greater flexural stiffness in the plane perpendicular to the original leaf placement than in the parallel plane. The xylem in the node region was more flexible, but it had significantly greater tissue density than adjacent regions, contradicting the usual correlation between wood density and stiffness. Nodes can behave as spring-like joints in woody plants. For plagiotropic shoots, distichous phyllotaxy results in stems that resist up-and-down bending more than lateral back-and-forth movement. Thus, they may more effectively absorb applied loads from fruits, animals, wind, rain, and snow and resist stresses due to gravity without cracking and breaking. Under windy conditions, nodes may improve damping by absorbing vibrational energy and thus reducing oscillation damage. The effect of plant nodes also has biomimetic design implications for architects and material engineers.

  17. Dirac materials

    OpenAIRE

    Wehling, T. O.; Black-Schaffer, A. M.; Balatsky, A. V.

    2014-01-01

    A wide range of materials, like d-wave superconductors, graphene, and topological insulators, share a fundamental similarity: their low-energy fermionic excitations behave as massless Dirac particles rather than fermions obeying the usual Schrodinger Hamiltonian. This emergent behavior of Dirac fermions in condensed matter systems defines the unifying framework for a class of materials we call "Dirac materials''. In order to establish this class of materials, we illustrate how Dirac fermions ...

  18. Magnetic Materials

    Science.gov (United States)

    Spaldin, Nicola A.

    2003-04-01

    Magnetic materials are the foundation of multi-billion dollar industries and the focus of intensive research across many disciplines. This book covers the fundamentals, basic theories and applications of magnetism and conventional magnetic materials. Based on a lecture course given by Nicola Spaldin in the Materials Department at University of California, Santa Barbara, the book is ideal for a one- semester course in magnetic materials. It contains numerous homework problems and solutions.

  19. Mismatch repair deficient hematopoietic stem cells are preleukemic stem cells.

    Directory of Open Access Journals (Sweden)

    Yulan Qing

    Full Text Available Whereas transformation events in hematopoietic malignancies may occur at different developmental stages, the initial mutation originates in hematopoietic stem cells (HSCs, creating a preleukemic stem cell (PLSC. Subsequent mutations at either stem cell or progenitor cell levels transform the PLSC into lymphoma/leukemia initiating cells (LIC. Thymic lymphomas have been thought to develop from developing thymocytes. T cell progenitors are generated from HSCs in the bone marrow (BM, but maturation and proliferation of T cells as well as T-lymphomagenesis depends on both regulatory mechanisms and microenvironment within the thymus. We studied PLSC linked to thymic lymphomas. In this study, we use MSH2-/- mice as a model to investigate the existence of PLSC and the evolution of PLSC to LIC. Following BM transplantation, we found that MSH2-/- BM cells from young mice are able to fully reconstitute multiple hematopoietic lineages of lethally irradiated wild-type recipients. However, all recipients developed thymic lymphomas within three and four months post transplantation. Transplantation of different fractions of BM cells or thymocytes from young health MSH2-/- mice showed that an HSC enriched fraction always reconstituted hematopoiesis followed by lymphoma development. In addition, lymphomas did not occur in thymectomized recipients of MSH2-/- BM. These results suggest that HSCs with DNA repair defects such as MSH2-/- are PLSCs because they retain hematopoietic function, but also carry an obligate lymphomagenic potential within their T-cell progeny that is dependent on the thymic microenvironment.

  20. Symptoms after hospital discharge following hematopoietic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Gamze Oguz

    2014-01-01

    Full Text Available Aims: The purposes of this study were to assess the symptoms of hematopoietic stem cell transplant patients after hospital discharge, and to determine the needs of transplant patients for symptom management. Materials and Methods: The study adopted a descriptive design. The study sample comprised of 66 hematopoietic stem cell transplant patients. The study was conducted in Istanbul. Data were collected using Patient Information Form and Memorial Symptom Assessment Scale (MSAS. Results: The frequency of psychological symptoms in hematopoietic stem cell transplant patients after discharge period (PSYCH subscale score 2.11 (standard deviation (SD = 0.69, range: 0.93-3.80 was higher in hematopoietic stem cell transplant patients than frequency of physical symptoms (PHYS subscale score: 1.59 (SD = 0.49, range: 1.00-3.38. Symptom distress caused by psychological and physical symptoms were at moderate level (Mean = 1.91, SD = 0.60, range: 0.95-3.63 and most distressing symptoms were problems with sexual interest or activity, difficulty sleeping, and diarrhea. Patients who did not have an additional chronic disease obtained higher MSAS scores. University graduates obtained higher Global Distress Index (GDI subscale and total MSAS scores with comparison to primary school graduates. Total MSAS, MSAS-PHYS subscale, and MSAS-PSYCH subscale scores were higher in patients with low level of income (P < 0.05. The patients (98.5% reported to receive education about symptom management after hospital discharge. Conclusions: Hematopoietic stem cell transplant patients continue to experience many distressing physical or psychological symptoms after discharge and need to be supported and educated for the symptom management.

  1. Adipose Derived Mesenchymal Stem Cells In Wound Healing: A Clinical Review

    Directory of Open Access Journals (Sweden)

    Gunalp Uzun

    2014-08-01

    Full Text Available The aim of this article is to review clinical studies on the use of adipose derived mesenchymal stem cells in the treatment of chronic wounds. A search on PubMed was performed on April 30th, 2014 to identify the relevant clinical studies. We reviewed 13 articles that reported the use adipose derived stem cells in the treatment of different types of wounds. Adipose derived stem cells have the potential to be used in the treatment of chronic wounds. However, standard methods for isolation, storage and application of these cells are needed. New materials to transfer these stem cells to injured tissues should be investigated. [Dis Mol Med 2014; 2(4.000: 57-64

  2. Torrefaction of Yacon and Jerusalem Artichoke Stems as a Contribution to the Alternative Production of Inulin

    Science.gov (United States)

    Veselý, V.; Sobek, J.; Hanika, J.; Punčochář, M.

    Recommendable torrefaction conditions were specified on the grounds of GT and DTA curves for the specimen of crushed stems of Yacon and Jerusalem artichoke. The impact of the size of crushed stems particle on the torrefaction process was monitored. The stem crushing process was optimized based on the results. We tested the effect of torrefaction performed on pellets made of raw material and wood chips, of which the pellets were made afterwards. It has been unambiguously proven that it was sensible to pelletize torrefied chips, otherwise the pellets were losing their coherence and crumbled. We calculated the fuel calorific value and its dependence on the residence time in the reactor. The economic benefit of torrefaction is that the power necessary for evaporation and leaching artichoke cuttings in water is obtained by combusting torrefied crushed stems.

  3. Composite materials

    International Nuclear Information System (INIS)

    Sambrook, D.J.

    1976-01-01

    A superconductor composite is described comprising at least one longitudinally extending superconductor filament or bundle of sub-filaments, each filament or bundle of sub-filaments being surrounded by and in good electrical contact with a matrix material, the matrix material comprising a plurality of longitudinally extending cells of a metal of high electrical conductivity surrounded by a material of lower electrical conductivity. The high electrical conductivity material surrounding the superconducting filament or bundle of sub-filaments is interrupted by a radially extending wall of the material of the lower electrical conductivity, the arrangement being such that at least two superconductor filaments or sub-filaments are circumferentially circumscribed by a single annulus of the material of high electrical conductivity. The annulus is electrically interrupted by a radially extending wall of the material of low electrical conductivity

  4. Aerospace materials and material technologies

    CERN Document Server

    Wanhill, R

    2017-01-01

    This book is a comprehensive compilation of chapters on materials (both established and evolving) and material technologies that are important for aerospace systems. It considers aerospace materials in three Parts. Part I covers Metallic Materials (Mg, Al, Al-Li, Ti, aero steels, Ni, intermetallics, bronzes and Nb alloys); Part II deals with Composites (GLARE, PMCs, CMCs and Carbon based CMCs); and Part III considers Special Materials. This compilation has ensured that no important aerospace material system is ignored. Emphasis is laid in each chapter on the underlying scientific principles as well as basic and fundamental mechanisms leading to processing, characterization, property evaluation and applications. A considerable amount of materials data is compiled and presented in appendices at the end of the book. This book will be useful to students, researchers and professionals working in the domain of aerospace materials.

  5. Development of Emu oil-loaded PCL/collagen bioactive nanofibers for proliferation and stemness preservation of human adipose-derived stem cells: possible application in regenerative medicine.

    Science.gov (United States)

    Nejati-Koshki, Kazem; Pilehvar-Soltanahmadi, Younes; Alizadeh, Effat; Ebrahimi-Kalan, Abbas; Mortazavi, Yousef; Zarghami, Nosratollah

    2017-12-01

    Adipose tissue-derived stem cells (ASCs) are promising candidate in stem cell therapies, and maintaining their stemness potential is vital to achieve effective treatment. Natural-based scaffolds have been recently attracted increasing attention in nanomedicine and drug delivery. In the present study, a polymeric nanofibrous scaffold was developed based on the polycaprolactone/Collagen (PCL/Coll) containing Emu oil as a bioactive material to induce the proliferation of ASCs, while simultaneously preserving the stemness property of those cells. Fabrication of the electrospun Emu oil-loaded PCL/Coll nanofibers was confirmed by using FE-SEM, FTIR, and tensile test. ASCs were seeded on two types of nanofibers (PCL/Coll and Emu oil-loaded PCL/Coll) and their proliferation, cell cycle progression, and stemness gene expressions were evaluated using MTT, propidium iodide staining, and qPCR during 14 days, respectively. The results indicated that ASCs displayed improved adhesion capacity with the higher rates of bioactivity and proliferation on the Emu oil-loaded nanofibers than the other groups. The proliferation capacity of ASCs on Emu oil-loaded PCL/Coll nanofibers was further confirmed by the cell cycle progression analysis. It was also found that Emu oil-loaded nanofibers significantly up-regulated the expression of stemness markers including sox-2, nanog, oct4, klf4, and c-Myc. The results demonstrated that the nanofibers containing Emu oil can reinforce the cell adhesion and enhance ASCs proliferation while preserving their stemness; therefore, using scaffolds containing natural products may have a great potential to enhance the in vitro expansion capacity of ASCs in the field of stem cell therapy and regenerative medicine.

  6. Infrequent lesions involving the brain stem: assessment with magnetic resonance

    International Nuclear Information System (INIS)

    Gonzalez, Alejandro P.; Salvatico, Rosana; Romero, Carlos; Lambre, Hector; Trejo, Mariano; Meli, Francisco

    2005-01-01

    Purpose: Report five non frequent cases that involve the brain stem studied with MRI. Material and methods: 115 patients were evaluated retrospectively between January 2002 and March 2004. Five non frequent cases were selected. Their ages were between 3 and 75 years, and all of them were male. A 1.5 magnet was used. The diagnosis was made with the clinical evolution, blood and CSF analysis and in one case by biopsy. Results: The mentioned cases were posterior reversible leucoencephalopathy, rhombencephalitis due to listeria monocytogenes, brain stem infiltrating glioma, Leigh syndrome and pontine myelinolysis. Conclusions: We think that the reported cases have to be considered among the different diagnosis of the brainstem pathology, in spite of their non frequent presentation. (author)

  7. Following basal stem rot in young oil palm plantings.

    Science.gov (United States)

    Panchal, G; Bridge, P D

    2005-01-01

    The PCR primer GanET has previously been shown to be suitable for the specific amplification of DNA from Ganoderma boninense. A DNA extraction and PCR method has been developed that allows for the amplification of the G. boninense DNA from environmental samples of oil palm tissue. The GanET primer reaction was used in conjunction with a palm-sampling programme to investigate the possible infection of young palms through cut frond base surfaces. Ganoderma DNA was detected in frond base material at a greater frequency than would be expected by comparison with current infection levels. Comparisons are made between the height of the frond base infected, the number of frond bases infected, and subsequent development of basal stem rot. The preliminary results suggest that the development of basal stem rot may be more likely to occur when young lower frond bases are infected.

  8. Materials Discovery | Materials Science | NREL

    Science.gov (United States)

    Discovery Materials Discovery Images of red and yellow particles NREL's research in materials characterization of sample by incoming beam and measuring outgoing particles, with data being stored and analyzed Staff Scientist Dr. Zakutayev specializes in design of novel semiconductor materials for energy

  9. Klotho, stem cells, and aging.

    Science.gov (United States)

    Bian, Ao; Neyra, Javier A; Zhan, Ming; Hu, Ming Chang

    2015-01-01

    Aging is an inevitable and progressive biological process involving dysfunction and eventually destruction of every tissue and organ. This process is driven by a tightly regulated and complex interplay between genetic and acquired factors. Klotho is an antiaging gene encoding a single-pass transmembrane protein, klotho, which serves as an aging suppressor through a wide variety of mechanisms, such as antioxidation, antisenescence, antiautophagy, and modulation of many signaling pathways, including insulin-like growth factor and Wnt. Klotho deficiency activates Wnt expression and activity contributing to senescence and depletion of stem cells, which consequently triggers tissue atrophy and fibrosis. In contrast, the klotho protein was shown to suppress Wnt-signaling transduction, and inhibit cell senescence and preserve stem cells. A better understanding of the potential effects of klotho on stem cells could offer novel insights into the cellular and molecular mechanisms of klotho deficiency-related aging and disease. The klotho protein may be a promising therapeutic agent for aging and aging-related disorders.

  10. The pluripotency of hair follicle stem cells.

    Science.gov (United States)

    Hoffman, Robert M

    2006-02-01

    The hair follicle bulge area is an abundant, easily accessible source of actively growing, pluripotent adult stem cells. Nestin, a protein marker for neural stem cells, is also expressed in follicle stem cells as well as their immediate differentiated progeny. The nestin-expressing hair follicle stem cells differentiated into neurons, glial cells, keratinocytes and smooth muscle cells in vitro. Hair-follicle stem cells were implanted into the gap region of a severed sciatic nerve. The hair follicle stem cells greatly enhanced the rate of nerve regeneration and the restoration of nerve function. The follicle stem cells transdifferentiated largely into Schwann cells which are known to support neuron regrowth. Function of the rejoined sciatic nerve was measured by contraction of the gastrocnemius muscle upon electrical stimulation. After severing the tibial nerve and subsequent transplantation of hair-follicle stem cells, the transplanted mice recovered the ability to walk normally. These results suggest that hair-follicle stem cells provide an important accessible, autologous source of adult stem cells for regenerative medicine.

  11. Engineering Stem Cells for Biomedical Applications

    Science.gov (United States)

    Yin, Perry T.; Han, Edward

    2018-01-01

    Stem cells are characterized by a number of useful properties, including their ability to migrate, differentiate, and secrete a variety of therapeutic molecules such as immunomodulatory factors. As such, numerous pre-clinical and clinical studies have utilized stem cell-based therapies and demonstrated their tremendous potential for the treatment of various human diseases and disorders. Recently, efforts have focused on engineering stem cells in order to further enhance their innate abilities as well as to confer them with new functionalities, which can then be used in various biomedical applications. These engineered stem cells can take on a number of forms. For instance, engineered stem cells encompass the genetic modification of stem cells as well as the use of stem cells for gene delivery, nanoparticle loading and delivery, and even small molecule drug delivery. The present Review gives an in-depth account of the current status of engineered stem cells, including potential cell sources, the most common methods used to engineer stem cells, and the utilization of engineered stem cells in various biomedical applications, with a particular focus on tissue regeneration, the treatment of immunodeficiency diseases, and cancer. PMID:25772134

  12. Engineering Stem Cells for Biomedical Applications.

    Science.gov (United States)

    Yin, Perry T; Han, Edward; Lee, Ki-Bum

    2016-01-07

    Stem cells are characterized by a number of useful properties, including their ability to migrate, differentiate, and secrete a variety of therapeutic molecules such as immunomodulatory factors. As such, numerous pre-clinical and clinical studies have utilized stem cell-based therapies and demonstrated their tremendous potential for the treatment of various human diseases and disorders. Recently, efforts have focused on engineering stem cells in order to further enhance their innate abilities as well as to confer them with new functionalities, which can then be used in various biomedical applications. These engineered stem cells can take on a number of forms. For instance, engineered stem cells encompass the genetic modification of stem cells as well as the use of stem cells for gene delivery, nanoparticle loading and delivery, and even small molecule drug delivery. The present Review gives an in-depth account of the current status of engineered stem cells, including potential cell sources, the most common methods used to engineer stem cells, and the utilization of engineered stem cells in various biomedical applications, with a particular focus on tissue regeneration, the treatment of immunodeficiency diseases, and cancer. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Biomimetic Materials and Fabrication Approaches for Bone Tissue Engineering.

    Science.gov (United States)

    Kim, Hwan D; Amirthalingam, Sivashanmugam; Kim, Seunghyun L; Lee, Seunghun S; Rangasamy, Jayakumar; Hwang, Nathaniel S

    2017-12-01

    Various strategies have been explored to overcome critically sized bone defects via bone tissue engineering approaches that incorporate biomimetic scaffolds. Biomimetic scaffolds may provide a novel platform for phenotypically stable tissue formation and stem cell differentiation. In recent years, osteoinductive and inorganic biomimetic scaffold materials have been optimized to offer an osteo-friendly microenvironment for the osteogenic commitment of stem cells. Furthermore, scaffold structures with a microarchitecture design similar to native bone tissue are necessary for successful bone tissue regeneration. For this reason, various methods for fabricating 3D porous structures have been developed. Innovative techniques, such as 3D printing methods, are currently being utilized for optimal host stem cell infiltration, vascularization, nutrient transfer, and stem cell differentiation. In this progress report, biomimetic materials and fabrication approaches that are currently being utilized for biomimetic scaffold design are reviewed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Identification of the Cause of the Stem Neck Fracture in the Hip Joint Endoprosthesis

    Directory of Open Access Journals (Sweden)

    Ryniewicz A.M.

    2018-02-01

    Full Text Available Endoprosthesis stem fractures are among the rarest complications that occur after hip joint arthroplasty. The aim of this paper is to evaluate the causes of the fractures of the Aura II stem neck, which is an element of an endoprosthesis implanted in a patient. In order to achieve it, a radiogram was evaluated, the FEM analysis was carried out for the hip joint replaced using the Aura II prosthesis and scanning tests as well as a chemical analysis were performed for the focus of fatigue. The tests performed indicate that the most probable causes leading to the fatigue fracture of the Aura II stem under examination were material defects in the process of casting and forging (forging the material with delamination and the presence of brittle oxides and carbides that resulted in a significant reduction of strength and resistance to corrosion. In the light of an unprecedented stem neck fracture, this information should be an indication for non-destructive tests of ready-made stems aiming to discover the material and technological defects that may arise in the process of casting and drop forging.

  15. Identification of the Cause of the Stem Neck Fracture in the Hip Joint Endoprosthesis

    Science.gov (United States)

    Ryniewicz, A. M.; Bojko, Ł.; Ryniewicz, A.; Pałka, P.; Ryniewicz, W.

    2018-02-01

    Endoprosthesis stem fractures are among the rarest complications that occur after hip joint arthroplasty. The aim of this paper is to evaluate the causes of the fractures of the Aura II stem neck, which is an element of an endoprosthesis implanted in a patient. In order to achieve it, a radiogram was evaluated, the FEM analysis was carried out for the hip joint replaced using the Aura II prosthesis and scanning tests as well as a chemical analysis were performed for the focus of fatigue. The tests performed indicate that the most probable causes leading to the fatigue fracture of the Aura II stem under examination were material defects in the process of casting and forging (forging the material with delamination and the presence of brittle oxides and carbides) that resulted in a significant reduction of strength and resistance to corrosion. In the light of an unprecedented stem neck fracture, this information should be an indication for non-destructive tests of ready-made stems aiming to discover the material and technological defects that may arise in the process of casting and drop forging.

  16. Achieving effective confinement through utilization of non-Newtonian fluid mixture as stemming structure

    Directory of Open Access Journals (Sweden)

    Luís Felipe Gomes Marinho

    Full Text Available Abstract The economics of a mining operation is directly influenced by blasting outcomes, where blasting aims to comminute the rock mass in order to attain smaller grain sizes to be loaded and hauled at a minimum cost for its first processing stage. In order to promote adequate rock breakage, the stemming structure needs to provide proper confinement for the borehole charged with explosives, reflecting the energy released during the detonation in form of shock waves and gases to act throughout the in situ rock mass, enlarging its failures and fractures, and also creating new ones. To build up a stemming column, literature recommends the usage of dry granular materials instead of elements with plastic behavior. However, a study was performed using Gypsum plaster as stemming; a kind of material that exhibits solid-like behavior when it is dry. Following this theory, this test verified improvements regarding confinement effectiveness and energy propagation throughout the rock mass when a non-Newtonian mixture (NNM was applied as stemming; a material that shows a solid-like behavior when is under shear stress. When the stemming arrangement was composed of NNM, it was able to reduce energy and gas losses to the atmosphere, because of the liquid's property of filling voids into the borehole. The NNM yielded high results due to its better confinement effectiveness, a reduction of air overpressure, and an increase of the strain propagation and ground vibration throughout the rock.

  17. Increasing College Students' Interest and Engagement in STEM: A Comparison of Strategies for Challenging STEM Stereotypes

    Science.gov (United States)

    Shin, Jiyun Elizabeth L.

    Increasing science, technology, engineering, and mathematics (STEM) graduates has become an important part of the education agenda in the U.S. in recent years. Stereotypes about STEM (i.e., belief that STEM abilities are innate, and that European American men are best suited for STEM) have been identified as one of the critical factors that may contribute to low recruitment and retention of STEM students. Drawing from the literatures on biological essentialism and role models, this study compared different strategies for challenging STEM stereotypes among undergraduate students in STEM and non-STEM fields. STEM stereotypes were challenged directly with research articles that provided non-biological explanations for STEM success and interest (a strategy used in the essentialism research) and indirectly with biographies of successful STEM role models who are underrepresented in their field and who succeeded through hard work (a strategy used in the role model research). Contrary to the predictions, exposure to the role model biographies, research articles, or combination of both did not have statistically significant effects on participants' reported STEM interest and academic intentions. Possible explanations for the lack of significant findings as well as suggestions for developing effective interventions to promote STEM engagement among students are discussed.

  18. Nano Materials

    International Nuclear Information System (INIS)

    Jin, In Ju; Lee, Ik Mo; Kwon, Yeung Gu

    2006-02-01

    This book introduces background of nano science such as summary, plenty room at the bottom, access way to nano technique, nanoparticles using bottom-up method which are a marvel of nature, and modern alchemy : chemical synthesis of artificial nano structure, understanding of quantum mechanics, STM/AFM, nano metal powder, ceramic nanoparticles, nano structure film, manufacture of nanoparticles using reverse micelle method, carbon nano tube, sol-gel material, nano energy material, nano catalyst nano bio material technology and spintronics.

  19. Material Systems

    DEFF Research Database (Denmark)

    Jensen, Mads Brath; Mortensen, Henrik Rubæk; Mullins, Michael

    2009-01-01

    This paper describes and reflects upon the results of an investigative project which explores the setting up of a material system - a parametric and generative assembly consisting of and taking into consideration material properties, manufacturing constraints and geometric behavior. The project...... approaches the subject through the construction of a logic-driven system aiming to explore the possibilities of a material system that fulfills spatial, structural and performative requirements concurrently and how these are negotiated in situations where they might be conflicting....

  20. Material focus

    DEFF Research Database (Denmark)

    Sokoler, Tomas; Vallgårda, Anna K. A.

    2009-01-01

    In this paper we build on the notion of computational composites, which hold a material perspective on computational technology. We argue that a focus on the material aspects of the technology could be a fruitful approach to achieve new expressions and to gain a new view on the technology's role...... in design. We study two of the computer's material properties: computed causality and connectability and through developing two computational composites that utilize these properties we begin to explore their potential expressions....

  1. Materializing Ethnography

    OpenAIRE

    Geismar, H.; Horst, H. A.

    2004-01-01

    The articles in this volume were originally presented in a panel entitled ‘Material Methodologies’ at the American Anthropological Association meeting in New Orleans (November 2002). The panel was devised to tie together theoretical advances in the study of the material with the creative possibilities of fieldwork practices. Through detailed ethnographic discussion, we highlighted the ways in which a focus on a specifically material world enabled us to discover new perspecti...

  2. Pharmacobotanic characterization of young stems and stem barks of Rauvolfia sellowii Müll. Arg., Apocynaceae

    Directory of Open Access Journals (Sweden)

    Leopoldo Clemente Baratto

    2010-09-01

    Full Text Available Rauvolfia sellowii Müll. Arg. (Apocynaceae, a Brazilian native tree rich in indole alkaloids, is known as "pau-pra-tudo" and popularly used as hypocholesterolemic, hypoglycemic and antihypertensive. The aim of this work was to study the anatomy of the young stems and stem barks of this medicinal plant, in order to contribute to the identification of the species as a drug. The plant material was fixed and prepared according to standard microtechniques. The young stems have remaining epidermis, but a suberified peridermis is evident. The phellogen is located in the cortical region, forming suber externally. Underneath the phellogen, lies the phelloderm and collenchymatic region. In the cortex, there are numerous laticifers and some fibers. There is an incomplete sclerenchymatic sheath, consisting of several groups of fibers and stone cells. The stem has internal phloem ordered as isolated groups side by side. Numerous laticifers, calcium oxalate crystals, idioblasts and amyloplasts are found in the cortex, phloem, xylem and pith. The stem bark has many layers of suber and cortical parenchyma, a sheath composed of fibers and stone cells totally lignified, and external phloem. These anatomical characteristic, taken together, can be used as quality control parameters for this species.Rauvolfia sellowii Müll. Arg. (Apocynaceae, uma árvore nativa brasileira rica em alcaloides indólicos, é conhecida como "pau-pra-tudo" e utilizada popularmente como hipocolesterolêmica, hipoglicêmica e anti-hipertensiva. O presente trabalho teve como objetivo caracterizar anatomicamente o caule jovem e a casca caulinar dessa planta medicinal, a fim de contribuir para a identificação e autenticidade da droga. O material vegetal foi fixado e submetido às microtécnicas usuais. O caule jovem possui epiderme remanescente, porém uma periderme suberificada é observada. O felogênio instala-se na região cortical, formando súber externamente. Subjacentes ao felog

  3. Materials characterisation

    International Nuclear Information System (INIS)

    Azali Muhammad

    2005-01-01

    Various nuclear techniques have been developed and employed by technologies and scientists worldwide to physically and chemically characterise the material particularly those that have applications in industry. These include small angle neutron scattering (SANS), x-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) for the internal structural study of material, whereas, the x-ray fluorescence (XRF) for the chemical analysis, while the Moessbauer spectroscopy for the study on the magnetic properties and structural identity of material. Basic principle and instrumentations of the techniques are discussed in this chapter. Example of their applications in various disciplines particularly in characterisation of industrial materials also described

  4. Stem and ICT education in intelligent environments

    CERN Document Server

    Kanematsu, Hideyuki

    2016-01-01

    This book combines information communication technology (ICT) with the creative interdisciplinary teaching approach known as STEM (science, technology, engineering, and mathematics). It introduces STEM and Creative Education and shows (through examples and creative activities) the importance and impact that ICT has for STEM and modern education.  The book describes the audio visual classroom, the use of the Internet, Social Networking and STEM, and provides STEM lessons for both the real and virtual worlds. Instructors will find this unique textbook to be very useful with students, of various ages, in creative education and engineering classes. This special book offers something for everyone. It serves as a guide for teachers in charge of science fairs and creative classes, especially those which require STEM education. It also includes activities to help develop creative thinking and problem-solving skills, and prepares students who plan to become teachers and mentors of the future. Readers in general can s...

  5. Proliferative capacity of murine hematopoietic stem cells

    International Nuclear Information System (INIS)

    Hellman, S.; Botnick, L.E.; Hannon, E.C.; Vigneulle, R.M.

    1978-01-01

    The present study demonstrates a decrease in self-renewal capacity with serial transfer of murine hematopoietic stem cells. Production of differentiated cell progeny is maintained longer than stem cell self-renewal. In normal animals the capacity for self-renewal is not decreased with increasing donor age. The stem cell compartment in normal animals, both young and old, appears to be proliferatively quiescent. After apparent recovery from the alkylating agent busulfan, the probability of stem cell self-renewal is decreased, there is a permanent defect in the capacity of the bone marrow for serial transplantation, and the stem cells are proliferatively active. These findings support a model of the hematopoietic stem cell compartment as a continuum of cells with decreasing capacities for self-renewal, increasing likelihood for differentiation, and increasing proliferative activity. Cells progress in the continuum in one direction and such progression is not reversible

  6. Strategies for future histocompatible stem cell therapy

    DEFF Research Database (Denmark)

    Nehlin, Jan; Barington, Torben

    2009-01-01

    Stem cell therapy based on the safe and unlimited self-renewal of human pluripotent stem cells is envisioned for future use in tissue or organ replacement after injury or disease. A gradual decline of regenerative capacity has been documented among the adult stem cell population in some body organs...... during the aging process. Recent progress in human somatic cell nuclear transfer and inducible pluripotent stem cell technologies has shown that patient-derived nuclei or somatic cells can be reprogrammed in vitro to become pluripotent stem cells, from which the three germ layer lineages can be generated......, genetically identical to the recipient. Once differentiation protocols and culture conditions can be defined and optimized, patient-histocompatible pluripotent stem cells could be directed towards virtually every cell type in the human body. Harnessing this capability to enrich for given cells within...

  7. Of Microenvironments and Mammary Stem Cells

    Energy Technology Data Exchange (ETDEWEB)

    LaBarge, Mark A; Petersen, Ole W; Bissell, Mina J

    2007-06-01

    In most adult tissues there reside pools of stem and progenitor cells inside specialized microenvironments referred to as niches. The niche protects the stem cells from inappropriate expansion and directs their critical functions. Thus guided, stem cells are able to maintain tissue homeostasis throughout the ebb and flow of metabolic and physical demands encountered over a lifetime. Indeed, a pool of stem cells maintains mammary gland structure throughout development, and responds to the physiological demands associated with pregnancy. This review discusses how stem cells were identified in both human and mouse mammary glands; each requiring different techniques that were determined by differing biological needs and ethical constraints. These studies together create a robust portrait of mammary gland biology and identify the location of the stem cell niche, elucidate a developmental hierarchy, and suggest how the niche might be manipulated for therapeutic benefit.

  8. Combination stem cell therapy for heart failure

    Directory of Open Access Journals (Sweden)

    Ichim Thomas E

    2010-04-01

    Full Text Available Abstract Patients with congestive heart failure (CHF that are not eligible for transplantation have limited therapeutic options. Stem cell therapy such as autologous bone marrow, mobilized peripheral blood, or purified cells thereof has been used clinically since 2001. To date over 1000 patients have received cellular therapy as part of randomized trials, with the general consensus being that a moderate but statistically significant benefit occurs. Therefore, one of the important next steps in the field is optimization. In this paper we discuss three ways to approach this issue: a increasing stem cell migration to the heart; b augmenting stem cell activity; and c combining existing stem cell therapies to recapitulate a "therapeutic niche". We conclude by describing a case report of a heart failure patient treated with a combination stem cell protocol in an attempt to augment beneficial aspects of cord blood CD34 cells and mesenchymal-like stem cells.

  9. Barriers To Successful Implementation of STEM Education

    Directory of Open Access Journals (Sweden)

    James A. Ejiwale

    2013-05-01

    Full Text Available The implementation of STEM education in schools across the globe is to prepare the future workforce with strong scientific and mathematical backgrounds to enhance skills development across STEM disciplines. However, for STEM education to achieve its goals and objectives, addressing the barriers to STEM education should start by fixing the problems at the elementary, junior and senior high school levels; the grassroots and potential feeders to colleges and universities. Since many nations including the United States of America is in dire need of the workforce with adequate preparation in science and mathematics to help address the nation’s economy that is in shambles, the barriers to its successful implementation should be identified and addressed. In this paper, (a the definition of STEM education and (b some barriers to successful implementation of STEM education are discussed and elaborated.

  10. Stem Cells and Herbal Acupuncture Therapy

    Directory of Open Access Journals (Sweden)

    Ki Rok Kwon

    2005-12-01

    Full Text Available Stem cell therapy implies the birth of regenerative medicine. Regenerative medicine signify treatment through regeneration of cells which was impossible by existing medicine. Stem cell is classified into embryonic stem cell and adult stem cell and they have distinctive benefits and limitations. Researches on stem cell are already under active progression and is expected to be commercially available in the near future. One may not relate the stem cell treatment with Oriental medicine, but can be interpreted as the fundamental treatment action of Oriental medicine is being investigated in more concrete manner. When it comes to difficult to cure diseases, there is no boundary between eastern and western medicine, and one must be ready to face and overcome changes lying ahead.

  11. Cellular Mechanisms of Somatic Stem Cell Aging

    Science.gov (United States)

    Jung, Yunjoon

    2014-01-01

    Tissue homeostasis and regenerative capacity rely on rare populations of somatic stem cells endowed with the potential to self-renew and differentiate. During aging, many tissues show a decline in regenerative potential coupled with a loss of stem cell function. Cells including somatic stem cells have evolved a series of checks and balances to sense and repair cellular damage to maximize tissue function. However, during aging the mechanisms that protect normal cell function begin to fail. In this review, we will discuss how common cellular mechanisms that maintain tissue fidelity and organismal lifespan impact somatic stem cell function. We will highlight context-dependent changes and commonalities that define aging, by focusing on three age-sensitive stem cell compartments: blood, neural, and muscle. Understanding the interaction between extrinsic regulators and intrinsic effectors that operate within different stem cell compartments is likely to have important implications for identifying strategies to improve health span and treat age-related degenerative diseases. PMID:24439814

  12. Therapeutic application of multipotent stem cells

    DEFF Research Database (Denmark)

    Mirzaei, Hamed; Sahebkar, Amirhossein; Sichani, Laleh Shiri

    2018-01-01

    Cell therapy is an emerging fields in the treatment of various diseases such as cardiovascular, pulmonary, hepatic, and neoplastic diseases. Stem cells are an integral tool for cell therapy. Multipotent stem cells are an important class of stem cells which have the ability to self-renew through...... been showed that multipotent stem cells exert their therapeutic effects via inhibition/activation of a sequence of cellular and molecular pathways. Although the advantages of multipotent stem cells are numerous, further investigation is still necessary to clarify the biology and safety of these cells...... before they could be considered as a potential treatment for different types of diseases. This review summarizes different features of multipotent stem cells including isolation, differentiation, and therapeutic applications....

  13. Therapeutic potential of adult stem cells

    DEFF Research Database (Denmark)

    Serakinci, Nedime; Keith, W. Nicol

    2006-01-01

    is the necessity to be able to identify, select, expand and manipulate cells outside the body. Recent advances in adult stem cell technologies and basic biology have accelerated therapeutic opportunities aimed at eventual clinical applications. Adult stem cells with the ability to differentiate down multiple...... lineages are an attractive alternative to human embryonic stem cells (hES) in regenerative medicine. In many countries, present legislation surrounding hES cells makes their use problematic, and indeed the origin of hES cells may represent a controversial issue for many communities. However, adult stem...... cells are not subject to these issues. This review will therefore focus on adult stem cells. Based on their extensive differentiation potential and, in some cases, the relative ease of their isolation, adult stem cells are appropriate for clinical development. Recently, several observations suggest...

  14. Autophagy regulates the stemness of cervical cancer stem cells

    Directory of Open Access Journals (Sweden)

    Yang Y

    2017-06-01

    Full Text Available Yi Yang,1,2 Li Yu,1 Jin Li,1 Ya Hong Yuan,1 Xiao Li Wang,1 Shi Rong Yan,1 Dong Sheng Li,1 Yan Ding1 1Hubei Key Laboratory of Embryonic Stem Cell Research, 2Reproductive Center, Taihe Hospital, Hubei University of Medicine, Shiyan, People’s Republic of China Abstract: Cancer stem cells (CSCs are a rare population of multipotent cells with the capacity to self-renew. It has been reported that there are CSCs in cervical cancer cells. Pluripotency-associated (PA transcription factors such as Oct4, Sox2, Nanog and CD44 have been used to isolate CSCs subpopulations. In this study, we showed that autophagy plays an important role in the biological behavior of cervical cancer cells. The expression of the autophagy protein Beclin 1 and LC3B was higher in tumorspheres established from human cervical cancers cell lines (and CaSki than in the parental adherent cells. It was also observed that the basal and starvation-induced autophagy flux was higher in tumorspheres than in the bulk population. Autophagy could regulate the expression level of PA proteins in cervical CSCs. In addition, CRISPR/Cas 9-mediated Beclin 1 knockout enhanced the malignancy of HeLa cells, leading to accumulation of PA proteins and promoted tumorsphere formation. Our findings suggest that autophagy modulates homeostasis of PA proteins, and Beclin 1 is critical for CSC maintenance and tumor development in nude mice. This demonstrates that a prosurvival autophagic pathway is critical for CSC maintenance. Keywords: cervical cancer, autophagy, cancer stem cell, LC3, Oct4

  15. Northeast Tennessee Educators' Perception of STEM Education Implementation

    Science.gov (United States)

    Turner, Kristin Beard

    2013-01-01

    A quantitative nonexperimental survey study was developed to investigate Northeast Tennessee K-8 educators' perceptions of STEM education. This study was an examination of current perceptions of STEM education. Perceived need, current implementation practices, access to STEM resources, definition of STEM, and the current condition of STEM in…

  16. Update on small intestinal stem cells

    OpenAIRE

    Tesori, Valentina; Puglisi, Maria Ausiliatrice; Lattanzi, Wanda; Gasbarrini, Giovanni Battista; Gasbarrini, Antonio

    2013-01-01

    Among somatic stem cells, those residing in the intestine represent a fascinating and poorly explored research field. Particularly, somatic stem cells reside in the small intestine at the level of the crypt base, in a constant balance between self-renewal and differentiation. Aim of the present review is to delve into the mechanisms that regulate the delicate equilibrium through which intestinal stem cells orchestrate intestinal architecture. To this aim, special focus will be addressed to id...

  17. Ethical Issues in Stem Cell Research

    OpenAIRE

    Lo, Bernard; Parham, Lindsay

    2009-01-01

    Stem cell research offers great promise for understanding basic mechanisms of human development and differentiation, as well as the hope for new treatments for diseases such as diabetes, spinal cord injury, Parkinson’s disease, and myocardial infarction. However, human stem cell (hSC) research also raises sharp ethical and political controversies. The derivation of pluripotent stem cell lines from oocytes and embryos is fraught with disputes about the onset of human personhood. The reprogramm...

  18. Stem cell aging: Survival of the laziest?

    OpenAIRE

    Muller-Sieburg, Christa; Sieburg, Hans B.

    2008-01-01

    The question whether stem cells age remains an enigma. Traditionally, aging was thought to change the properties of hematopoietic stem cells (HSC). We discuss here a new model of stem cell aging that challenges this view. It is now well-established that the HSC compartment is heterogeneous, consisting of epigenetically fixed subpopulations of HSC that differ in self-renewal and differentiation capacity. New data show that the representation of these HSC subsets changes during aging. HSC that ...

  19. Stem Cell Therapies in Orthopaedic Trauma

    OpenAIRE

    Marcucio, Ralph S.; Nauth, Aaron; Giannoudis, Peter V.; Bahney, Chelsea; Piuzzi, Nicolas S.; Muschler, George; Miclau, Theodore

    2015-01-01

    Stem cells offer great promise to help understand the normal mechanisms of tissue renewal, regeneration, and repair, and also for development of cell-based therapies to treat patients after tissue injury. Most adult tissues contain stem cells and progenitor cells that contribute to homeostasis, remodeling and repair. Multiple stem and progenitor cell populations in bone are found in the marrow, the endosteum, and the periosteum. They contribute to the fracture healing process after injury and...

  20. Pluripotent stem cell-derived neural stem cells: From basic research to applications

    OpenAIRE

    Otsu, Masahiro; Nakayama, Takashi; Inoue, Nobuo

    2014-01-01

    Basic research on pluripotent stem cells is designed to enhance understanding of embryogenesis, whereas applied research is designed to develop novel therapies and prevent diseases. Attainment of these goals has been enhanced by the establishment of embryonic stem cell lines, the technological development of genomic reprogramming to generate induced-pluripotent stem cells, and improvements in vitro techniques to manipulate stem cells. This review summarizes the techniques required to generate...

  1. New materials

    International Nuclear Information System (INIS)

    Joshi, S.K.; Rao, C.N.R.; Tsuruta, T.

    1992-01-01

    The book contains the state-of-the art lectures delivered at the discussion meeting on new materials, a field in which rapid advances are taking place. The main objective of the meeting was to bring active scientists in this area from Japan and India together. The topics covered diverse aspects of modern materials including high temperature superconducting compounds. (M.G.B.)

  2. Materials science

    International Nuclear Information System (INIS)

    2002-01-01

    the document is a collection of papers on different aspects of materials science. It discusses many items such as semiconductors, surface properties and interfaces, construction and civil engineering, metallic materials, polymers and composites, biology and biomaterials, metallurgy etc.. - 1 - Document1 Document1

  3. Stem cell biology meets systems biology

    OpenAIRE

    Roeder, I.; Radtke, F.

    2009-01-01

    Stem cells and their descendents are the building blocks of life. How stem cell populations guarantee their maintenance and/or self-renewal, and how individual stem cells decide to transit from one cell stage to another to generate different cell types are long-standing and fascinating questions in the field. Here, we review the discussions that took place at a recent EMBO conference in Cambridge, UK, in which these questions were placed in the context of the latest advances in stem cell biol...

  4. Stem cells: limitations and opportunities in Peru

    OpenAIRE

    Amiel-Pérez, José; Laboratorio de Cultivos Celulares, Universidad Científica del Sur. Lima, Perú.; Casado, Fanny; Stem Cell and Cancer Research Institute, McMaster University. Hamilton, Canadá.

    2015-01-01

    Stem cells are defined as rare cells that are characterized by asymmetric division, a process known as self-renewal, and the potential to differentiate into more than one type of terminally differentiated cell. There is a diversity of stem cells including embryonic stem cells, which exist only during the first stages of human development, and many adult stem cells depending on the specific tissues from where they derive or the ones derived from mesenchymal or stromal tissues. On the other han...

  5. Mesenchymal dental stem cells in regenerative dentistry.

    Science.gov (United States)

    Rodríguez-Lozano, Francisco-Javier; Insausti, Carmen-Luisa; Iniesta, Francisca; Blanquer, Miguel; Ramírez, María-del-Carmen; Meseguer, Luis; Meseguer-Henarejos, Ana-Belén; Marín, Noemí; Martínez, Salvador; Moraleda, José-María

    2012-11-01

    In the last decade, tissue engineering is a field that has been suffering an enormous expansion in the regenerative medicine and dentistry. The use of cells as mesenchymal dental stem cells of easy access for dentist and oral surgeon, immunosuppressive properties, high proliferation and capacity to differentiate into odontoblasts, cementoblasts, osteoblasts and other cells implicated in the teeth, suppose a good perspective of future in the clinical dentistry. However, is necessary advance in the known of growth factors and signalling molecules implicated in tooth development and regeneration of different structures of teeth. Furthermore, these cells need a fabulous scaffold that facility their integration, differentiation, matrix synthesis and promote multiple specific interactions between cells. In this review, we give a brief description of tooth development and anatomy, definition and classification of stem cells, with special attention of mesenchymal stem cells, commonly used in the cellular therapy for their trasdifferentiation ability, non ethical problems and acceptable results in preliminary clinical trials. In terms of tissue engineering, we provide an overview of different types of mesenchymal stem cells that have been isolated from teeth, including dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHEDs), periodontal ligament stem cells (PDLSCs), dental follicle progenitor stem cells (DFPCs), and stem cells from apical papilla (SCAPs), growth factors implicated in regeneration teeth and types of scaffolds for dental tissue regeneration.

  6. Stem cell therapy to treat heart ischaemia

    DEFF Research Database (Denmark)

    Ali Qayyum, Abbas; Mathiasen, Anders Bruun; Kastrup, Jens

    2014-01-01

    (CABG), morbidity and mortality is still high in patients with CAD. Along with PCI and CABG or in patients without options for revascularization, stem cell regenerative therapy in controlled trials is a possibility. Stem cells are believed to exert their actions by angiogenesis and regeneration...... of cardiomyocytes. Recently published clinical trials and meta-analysis of stem cell studies have shown encouraging results with increased left ventricle ejection fraction and reduced symptoms in patients with CAD and heart failure. There is some evidence of mesenchymal stem cell being more effective compared...... to other cell types and cell therapy may be more effective in patients with known diabetes mellitus. However, further investigations are warranted....

  7. Hardwiring Stem Cell Communication through Tissue Structure.

    Science.gov (United States)

    Xin, Tianchi; Greco, Valentina; Myung, Peggy

    2016-03-10

    Adult stem cells across diverse organs self-renew and differentiate to maintain tissue homeostasis. How stem cells receive input to preserve tissue structure and function largely relies on their communication with surrounding cellular and non-cellular elements. As such, how tissues are organized and patterned not only reflects organ function, but also inherently hardwires networks of communication between stem cells and their environment to direct tissue homeostasis and injury repair. This review highlights how different methods of stem cell communication reflect the unique organization and function of diverse tissues. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Nanomaterials for Engineering Stem Cell Responses.

    Science.gov (United States)

    Kerativitayanan, Punyavee; Carrow, James K; Gaharwar, Akhilesh K

    2015-08-05

    Recent progress in nanotechnology has stimulated the development of multifunctional biomaterials for tissue engineering applications. Synergistic interactions between nanomaterials and stem cell engineering offer numerous possibilities to address some of the daunting challenges in regenerative medicine, such as controlling trigger differentiation, immune reactions, limited supply of stem cells, and engineering complex tissue structures. Specifically, the interactions between stem cells and their microenvironment play key roles in controlling stem cell fate, which underlines therapeutic success. However, the interactions between nanomaterials and stem cells are not well understood, and the effects of the nanomaterials shape, surface morphology, and chemical functionality on cellular processes need critical evaluation. In this Review, focus is put on recent development in nanomaterial-stem cell interactions, with specific emphasis on their application in regenerative medicine. Further, the emerging technologies based on nanomaterials developed over the past decade for stem cell engineering are reviewed, as well as the potential applications of these nanomaterials in tissue regeneration, stem cell isolation, and drug/gene delivery. It is anticipated that the enhanced understanding of nanomaterial-stem cell interactions will facilitate improved biomaterial design for a range of biomedical and biotechnological applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. [Bioethical challenges of stem cell tourism].

    Science.gov (United States)

    Ventura-Juncá, Patricio; Erices, Alejandro; Santos, Manuel J

    2013-08-01

    Stem cells have drawn extraordinary attention from scientists and the general public due to their potential to generate effective therapies for incurable diseases. At the same time, the production of embryonic stem cells involves a serious ethical issue concerning the destruction of human embryos. Although adult stem cells and induced pluripotential cells do not pose this ethical objection, there are other bioethical challenges common to all types of stem cells related particularly to the clinical use of stem cells. Their clinical use should be based on clinical trials, and in special situations, medical innovation, both of which have particular ethical dimensions. The media has raised unfounded expectations in patients and the public about the real clinical benefits of stem cells. At the same time, the number of unregulated clinics is increasing around the world, making direct offers through Internet of unproven stem cell therapies that attract desperate patients that have not found solutions in standard medicine. This is what is called stem cells tourism. This article reviews this situation, its consequences and the need for international cooperation to establish effective regulations to prevent the exploitation of patients and to endanger the prestige of legitimate stem cell research.

  10. Stem secondary growth of tundra shrubs

    DEFF Research Database (Denmark)

    Campioli, Matteo; Leblans, Niki; Michelsen, Anders

    2012-01-01

    Our knowledge of stem secondary growth of arctic shrubs (a key component of tundra net primary production, NPP) is very limited. Here, we investigated the impact of the physical elements of the environment on shrub secondary growth by comparing annual growth rates of model species from similar...... growth (stem apical growth, stem length, and apical growth of stem plus leaves), in some cases even with opposite responses. Thus caution should be taken when estimating the impact of the environment on shrub growth from apical growth only. Integration of our data set with the (very limited) previously...

  11. The Patentability of Stem Cells in Australia.

    Science.gov (United States)

    Petering, Jenny; Cowin, Prue

    2015-07-01

    The potential therapeutic applications of stem cells are unlimited. However, the ongoing political and social debate surrounding the intellectual property and patenting considerations of stem cell research has led to the implementation of strict legislative regulations. In Australia the patent landscape surrounding stem cells has evolved considerably over the past 20 years. The Australian Patents Act 1990 includes a specific exclusion to the patentability of human beings and of biological processes for their generation. However, this exclusion has received no judicial consideration to date, and so its scope and potential impact on stem cell patents is unclear. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  12. Hardwiring stem cell communication through tissue structure

    Science.gov (United States)

    Xin, Tianchi; Greco, Valentina; Myung, Peggy

    2016-01-01

    Adult stem cells across diverse organs self-renew and differentiate to maintain tissue homeostasis. How stem cells receive input to preserve tissue structure and function largely relies on their communication with surrounding cellular and non-cellular elements. As such, how tissues are organized and patterned not only reflects organ function but also inherently hardwires networks of communication between stem cells and their environment to direct tissue homeostasis and injury repair. This review highlights how different methods of stem cell communication reflect the unique organization and function of diverse tissues. PMID:26967287

  13. Stem Cell Therapy: An emerging science

    International Nuclear Information System (INIS)

    Khan, Muhammad M.

    2007-01-01

    The research on stem cells is advancing knowledge about the development of an organism from a single cell and to how healthy cells replace damaged cells in adult organisms. Stem cell therapy is emerging rapidly nowadays as a technical tool for tissue repair and replacement. The purpose of this review to provide a framework of understanding for the challenges behind translating fundamental stem cell biology and its potential use into clinical therapies, also to give an overview on stem cell research to the scientists of Saudi Arabia in general. English language MEDLINE publications from 1980 through January 2007 for experimental, observational and clinical studies having relation with stem cells with different diseases were reviewed. Approximately 85 publications were reviewed based on the relevance, strength and quality of design and methods, 36 publications were selected for inclusion. Stem cells reside in a specific area of each tissue where they may remain undivided for several years until they are activated by disease or tissue injury. The embryonic stem cells are typically derived from four or five days old embryos and they are pluripotent. The adult tissues reported to contain stem cells brain, bone marrow, peripheral blood, blood vessels, skeletal muscle, skin and liver. The promise of stem cell therapies is an exciting one, but significant technical hurdles remain that will only be overcome through years of intensive research. (author)

  14. Extensively coated revision stems in proximally deficient femur: Early results in 15 patients

    Directory of Open Access Journals (Sweden)

    Marya SKS

    2008-01-01

    Full Text Available Background: Hip replacement following failed internal fixation (dynamic hip screw for intertrochanteric fractures or previous hip arthroplasty presents a major surgical challenge. Proximal fitting revision stems do not achieve adequate fixation. Distal fixation with long-stemmed extensively coated cementless implants (like the Solution™ system affords a suitable solution. We present our early results of 15 patients treated with extensively coated cementless revision stems. Materials and Methods: Fifteen patients with severely compromised proximal femora following either failed hip arthroplasty or failed internal fixation (dynamic hip screw fixation for intertrochanteric fractures were operated by the senior author over a two-year period. Eight patients had aseptic loosening of their femoral stems following cemented hip replacements, with severe thinning of their proximal cortices and impending stress fractures. Seven had secondary hip arthritis following failure of long implants for comminuted intertrochanteric or subtrochanteric femoral fractures. All patients were treated by removal of implant (cemented stems/DHS implants and insertion of long-stemmed extensively coated cementless revision (′ Solution™; DePuy, Warsaw (IN, US′ stems along with press-fit acetabular component (Duraloc Cup, DePuy, Warsaw (IN, US. All eight hip revisions needed extended trochanteric osteotomies. Results: All patients were primarily kept in bed on physiotherapy for six weeks and then gradually progressed to weight-bearing walking over the next six to eight weeks. The Harris Hip Scores and patient satisfaction were used for final evaluation. We achieved good results in the short term studied. In our first three patients (all following failed cemented total hip replacements, we resorted to cerclage wiring to hold osteotomised segments (done to facilitate stem removal. The subsequent 12 proceeded without the need for cerclage wiring. One patient had a

  15. Material Programming

    DEFF Research Database (Denmark)

    Vallgårda, Anna; Boer, Laurens; Tsaknaki, Vasiliki

    2017-01-01

    . Consequently we ask what the practice of programming and giving form to such materials would be like? How would we be able to familiarize ourselves with the dynamics of these materials and their different combinations of cause and effect? Which tools would we need and what would they look like? Will we program......, and color, but additionally being capable of sensing, actuating, and computing. Indeed, computers will not be things in and by themselves, but embedded into the materials that make up our surroundings. This also means that the way we interact with computers and the way we program them, will change...... these computational composites through external computers and then transfer the code them, or will the programming happen closer to the materials? In this feature we outline a new research program that floats between imagined futures and the development of a material programming practice....

  16. Composite material

    Science.gov (United States)

    Hutchens, Stacy A [Knoxville, TN; Woodward, Jonathan [Solihull, GB; Evans, Barbara R [Oak Ridge, TN; O'Neill, Hugh M [Knoxville, TN

    2012-02-07

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  17. Materials science

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The Materials Science Division is engaged in research on physical properties of materials and the effects of radiation upon them. This involves solid state materials undergoing phase transitions, energy storing materials, and biomaterials. The Division also offers research facilities for M.S. and Ph.D. thesis work in the fields of physics, chemistry, materials, and radiation sciences in cooperation with the various colleges and departments of the UPR Mayaguez Campus. It is anticipated that it will serve as a catalyst in starting energy-related research programs in cooperation with UPR faculty, especially programs involving solar energy. To encourage and promote cooperative efforts, contact is maintained with former graduate students and with visiting scientists from Latin American research institutions

  18. Touching Materiality

    DEFF Research Database (Denmark)

    Rasmussen, Lisa Rosén

    2012-01-01

    Dripping ink pens, colourful paint on skin, vegetables pots on a school roof. In interviews with three generations of former school pupils, memories of material objects bore a relation to everyday school life in the past. Interwoven, these objects entered the memorising processes, taking...... the interviewer and interviewee beyond an exclusively linguistic understanding of memory. This article analyses how the shifting objects of materiality in personal and generational school memories connects to material as well as sensuous experiences of everyday school life and its complex processes of learning....... Drawing on anthropological writings, the article argues that the objects of materiality are part of important but non-verbalised memories of schooling. The Dutch philosopher Eelco Runia’s notions of presence and metonymy are incorporated as tools for approaching objects of materiality in memory studies....

  19. Confronting Color-Blind STEM Talent Development: Toward a Contextual Model for Black Student STEM Identity

    Science.gov (United States)

    Collins, Kristina Henry

    2018-01-01

    What is Black student's science, technology, engineering, and mathematics (STEM) identity? The author addresses this question through a synthesis of the literature that includes studies that explore Black student identity. Background information regarding STEM achievement and persistence followed by empirical studies that explore STEM attitudes…

  20. Promoting Strategic STEM Education Outreach Programming Using a Systems-Based STEM-EO Model

    Science.gov (United States)

    Ward, Annmarie R.

    2015-01-01

    In this paper a STEM Education Outreach (STEM-EO) Model for promoting strategic university outreach programming at Penn State University to the benefit of university, school district and community stakeholders is described. The model considers STEM-EO as a complex system involving overarching learning goals addressed within four outreach domains…

  1. Embryonic stem cells require Wnt proteins to prevent differentiation to epiblast stem cells

    NARCIS (Netherlands)

    D. ten Berge (Derk); D. Kurek (Dorota); T. Blauwkamp (Tim); W. Koole (Wouter); A. Maas (Alex); E. Eroglu (Elif); R.K. Siu (Ronald); R. Nusse (Roel)

    2011-01-01

    textabstractPluripotent stem cells exist in naive and primed states, epitomized by mouse embryonic stem cells (ESCs) and the developmentally more advanced epiblast stem cells (EpiSCs; ref.). In the naive state of ESCs, the genome has an unusual open conformation and possesses a minimum of repressive

  2. An Examination of Middle School Students' STEM Self-Efficacy with Relation to Interest and Perceptions of STEM

    Science.gov (United States)

    Brown, Patrick L.; Concannon, James P.; Marx, Donna; Donaldson, Christopher W.; Black, Alicia

    2016-01-01

    The purpose of this teacher research study is to ascertain students' interest in STEM and beliefs about STEM before and after STEM specific instruction, explore possible differences in STEM self-efficacy by gender, and explore differences in STEM self-efficacy by group role. Our primary data sources include a modified attitudinal survey and…

  3. Pollution! Find a STEM solution!

    Science.gov (United States)

    Takač, Danijela; Moćan, Marina

    2016-04-01

    Primary and secondary school Pantovčak is an innovative school in downtown Zagreb, Croatia. The school is involved in many projects concerning STEM education. Pollution! Find a STEM solution! is a two year long cross-curricular project that grew out of identified need to develop STEM and ICT skills more. Pisa results make evident that students' knowledge is poor and motivation for math and similar subjects is low. Implying priorities of European Commission, like e-learning, raises motivation and also develops basic skills and improves knowledge in science, math, physic, ICT. Main objectives are to increase students' interest in STEM education and careers and introduce them to all available new trends in technology, engineering and science in their region by visiting clean technology industries and strengthening links with them, to introduce some future digital jobs and prepare students for rapid technological changes by integrating ICT into classroom practice more, to highlight the importance of global environmental issues and improve the knowledge in the areas of sustainable development and renewable energy, to develop collaborative partnership between schools and the wider community in formal, non-formal and informal learning, to support multilingualism by publishing Open Educational Resources in 8 different languages and to strengthen the professional profile of the teaching profession. The project brings together 231 teachers and 2729 students from five different European countries in learning to think globally and work on activities that contribute to the community's well-being. There are altogether 33 activities, divided in 4 categories. STEM activities are focused on students building the devices for measuring air, light and noise pollution in their school and homes. They use the scientific method to analyze the data and compare the results with their peers to find a solution. Eskills, digital literacy and digital jobs are focused on introducing career

  4. Thermoacoustic design using stem of goose down stack

    Science.gov (United States)

    Farikhah, Irna; Ristanto, Sigit; Idrus, Hadiyati; Kaltsum, Ummi; Faisal, Affandi; Setiawan, Ihsan; Setio Utomo, Agung Bambang

    2012-09-01

    Many refrigerators using CFC as a refrigerant are seen as the cause of the depletion of ozone. Hence, thermoacoustic was chosen as an alternative refrigerator that safe for environment. There are many variable that influenced the optimization of thermoacoustic design. One of them is thermal conductivity of material of stack. The Stack material must have a low thermal conductivity. In this research we used organic stack made of stem of goose down. It has superior thermal insulating. It means that they have the lowest thermal conductivity. The system uses no refrigerant or compressor, and the only mechanical moving part is the loudspeaker connected to a signal generator that produces the acoustic. The working fluid is air and the material of resonator is stainless steel. A series test on the laboratory found that there is a decrease of 5°C in temperature for about 2 minutes.

  5. Effect of nanodiamond modification of siloxane surfaces on stem cell behaviour

    International Nuclear Information System (INIS)

    Keremidarska, M; Krasteva, N; Hikov, T; Radeva, E; Pramatarova, L

    2014-01-01

    Mesenchymal stem cells (MSCs) hold a great promise for use in many cell therapies and tissue engineering due to their remarkable potential to replicate indefinitely and differentiate into various cell types. Many efforts have been put to study the factors controlling stem cell differentiation. However, still little knowledge has been gained to what extent biomaterials properties influence stem cell adhesion, growth and differentiation. Research utilizing bone marrow-derived MSCs has concentrated on development of specific materials which can enhance specific differentiation of stem cells e.g. osteogenic and chondrogenic. In the present work we have modified an organosilane, hexamethyldisiloxane (HMDS) with detonation nanodiamond (DND) particles aiming to improve adhesion, growth and osteodifferentiation of rat mesenchymal stem cells. HMDS/DND films were deposited on cover glass using two approaches: premixing of both compounds, followed by plasma polymerization (PP) and PP of HMDS followed by plasma deposition of DND particles. We did not observe however an increase in rMSCs adhesion and growth on DND-modified PPHMDS surfaces compared to unmodified PPHMDS. When we studied alkaline phosphatase (ALP) activity, which is a major sign for early osteodifferentiation, we found the highest ALP activity on the PPHMDS/DND material, prepared by consequent deposition while on the other composite material ALP activity was the lowest. These results suggested that DND-modified materials were able to control osteodifferention in MSCs depending on the deposition approach. Modification of HMDS with DND particles by consequent plasma deposition seems to be a promising approach to produce biomaterials capable to guide stem cell differentiation toward osteoblasts and thus to be used in bone tissue engineering

  6. Effect of nanodiamond modification of siloxane surfaces on stem cell behaviour

    Science.gov (United States)

    Keremidarska, M.; Hikov, T.; Radeva, E.; Pramatarova, L.; Krasteva, N.

    2014-12-01

    Mesenchymal stem cells (MSCs) hold a great promise for use in many cell therapies and tissue engineering due to their remarkable potential to replicate indefinitely and differentiate into various cell types. Many efforts have been put to study the factors controlling stem cell differentiation. However, still little knowledge has been gained to what extent biomaterials properties influence stem cell adhesion, growth and differentiation. Research utilizing bone marrow-derived MSCs has concentrated on development of specific materials which can enhance specific differentiation of stem cells e.g. osteogenic and chondrogenic. In the present work we have modified an organosilane, hexamethyldisiloxane (HMDS) with detonation nanodiamond (DND) particles aiming to improve adhesion, growth and osteodifferentiation of rat mesenchymal stem cells. HMDS/DND films were deposited on cover glass using two approaches: premixing of both compounds, followed by plasma polymerization (PP) and PP of HMDS followed by plasma deposition of DND particles. We did not observe however an increase in rMSCs adhesion and growth on DND-modified PPHMDS surfaces compared to unmodified PPHMDS. When we studied alkaline phosphatase (ALP) activity, which is a major sign for early osteodifferentiation, we found the highest ALP activity on the PPHMDS/DND material, prepared by consequent deposition while on the other composite material ALP activity was the lowest. These results suggested that DND-modified materials were able to control osteodifferention in MSCs depending on the deposition approach. Modification of HMDS with DND particles by consequent plasma deposition seems to be a promising approach to produce biomaterials capable to guide stem cell differentiation toward osteoblasts and thus to be used in bone tissue engineering.

  7. Stepwise development of hematopoietic stem cells from embryonic stem cells.

    Directory of Open Access Journals (Sweden)

    Kenji Matsumoto

    Full Text Available The cellular ontogeny of hematopoietic stem cells (HSCs remains poorly understood because their isolation from and their identification in early developing small embryos are difficult. We attempted to dissect early developmental stages of HSCs using an in vitro mouse embryonic stem cell (ESC differentiation system combined with inducible HOXB4 expression. Here we report the identification of pre-HSCs and an embryonic type of HSCs (embryonic HSCs as intermediate cells between ESCs and HSCs. Both pre-HSCs and embryonic HSCs were isolated by their c-Kit(+CD41(+CD45(- phenotype. Pre-HSCs did not engraft in irradiated adult mice. After co-culture with OP9 stromal cells and conditional expression of HOXB4, pre-HSCs gave rise to embryonic HSCs capable of engraftment and long-term reconstitution in irradiated adult mice. Blast colony assays revealed that most hemangioblast activity was detected apart from the pre-HSC population, implying the early divergence of pre-HSCs from hemangioblasts. Gene expression profiling suggests that a particular set of transcripts closely associated with adult HSCs is involved in the transition of pre-HSC to embryonic HSCs. We propose an HSC developmental model in which pre-HSCs and embryonic HSCs sequentially give rise to adult types of HSCs in a stepwise manner.

  8. Stem cells and respiratory diseases

    Directory of Open Access Journals (Sweden)

    Soraia Carvalho Abreu

    2008-12-01

    Full Text Available Stem cells have a multitude of clinical implications in the lung. This article is a critical review that includes clinical and experimental studies of MedLine and SciElo database in the last 10 years, where we highlight the effects of stem cell therapy in acute respiratory distress syndrome or more chronic disorders such as lung fibrosis and emphysema. Although, many studies have shown the beneficial effects of stem cells in lung development, repair and remodeling; some important questions need to be answered to better understand the mechanisms that control cell division and differentiation, therefore enabling the use of cell therapy in human respiratory diseases.As células-tronco têm uma infinidade de implicações clínicas no pulmão. Este artigo é uma revisão crítica que inclui estudos clínicos e experimentais advindos do banco de dados do MEDLINE e SciElo nos últimos 10 anos, onde foram destacados os efeitos da terapia celular na síndrome do desconforto respiratório agudo ou doenças mais crônicas, como fibrose pulmonar e enfisema. Apesar de muitos estudos demonstrarem os efeitos benéficos das células-tronco no desenvolvimento, reparo e remodelamento pulmonar; algumas questões ainda precisam ser respondidas para um melhor entendimento dos mecanismos que controlam a divisão celular e diferenciação, permitindo o uso da terapia celular nas doenças respiratórias.

  9. Declaration on embryonic stem cells

    OpenAIRE

    Casado, María; Egozcue, Josep, 1940-2006

    2001-01-01

    El grupo ha analizado las cuestiones referentes a la obtención y utilización de células embrionarias, llamadas células stem, células madre o células troncales, tema de extraordinaria importancia científica en el momento actual, que suscita reacciones encontradas, de gran carga ideológica, y ante el cual se requiere un debate social informado, que permita establecer el suficiente consenso para que se pueda dar lugar a la correspondiente normativa jurídica.

  10. Regenerative medicine in dental and oral tissues: Dental pulp mesenchymal stem cell

    Directory of Open Access Journals (Sweden)

    Janti Sudiono

    2017-08-01

    Full Text Available Background. Regenerative medicine is a new therapeutic modality using cell, stem cell and tissue engineering technologies. Purpose. To describe the regenerative capacity of dental pulp mesenchymal stem cell. Review. In dentistry, stem cell and tissue engineering technologies develop incredibly and attract great interest, due to the capacity to facilitate innovation in dental material and regeneration of dental and oral tissues. Mesenchymal stem cells derived from dental pulp, periodontal ligament and dental follicle, can be isolated, cultured and differentiated into various cells, so that can be useful for regeneration of dental, nerves, periodontal and bone tissues. Tissue engineering is a technology in reconstructive biology, which utilizes mechanical, cellular, or biological mediators to facilitate regeneration or reconstruction of a particular tissue. The multipotency, high proliferation rates and accessibility, make dental pulp as an attractive source of mesenchymal stem cells for tissue regeneration. Revitalized dental pulp and continued root development is the focus of regenerative endodontic while biological techniques that can restore lost alveolar bone, periodontal ligament, and root cementum is the focus of regenerative periodontic. Conclucion. Dentin-derived morphogens such as BMP are known to be involved in the regulation of odontogenesis. The multipotency and angiogenic capacity of DPSCs as the regenerative capacity of human dentin / pulp complex indicated that dental pulp may contain progenitors that are responsible for dentin repair. The human periodontal ligament is a viable alternative source for possible primitive precursors to be used in stem cell therapy.

  11. Assessment of Surface Markers Derived from Human Periodontal Ligament Stem Cells: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Zainab Kadkhoda

    2016-12-01

    Full Text Available Objectives: Periodontal tissue regeneration for treatment of periodontal disease has not yet been mastered in tissue engineering. Stem cells, scaffold, and growth factors are the three main basic components of tissue engineering. Periodontal ligament (PDL contains stem cells; however, the number, potency and features of these cells have not yet been understood. This study aimed to isolate and characterize the properties of PDL stem cells. Materials and Methods: In this experimental study, samples were isolated from the PDL of extracted teeth of five patients and then stained immunohistochemically for detection of cell surface markers. Cells were then examined by immuno-flow cytometry for mesenchymal markers as well as for osteogenic and adipogenic differentiation.Results: The isolated cell population had fibroblast-like morphology and flow cytometry revealed that the mesenchymal surface markers were (means: CD90 (84.55, CD31 (39.97, CD166 (33.77, CD105 (31.19, CD45 (32/44, CD44 (462.11, CD34 (227.33, CD38 (86.94, CD13 (34.52 and CD73 (50.39. The PDL stem cells also differentiated into osteoblasts and adipocytes in osteogenic and adipogenic media, respectively.Conclusions: PDL stem cells expressed mesenchymal stem cell (MSC markers and differentiated into osteoblasts and adipocytes in osteogenic and adipogenic media, respectively.Keywords: Adipocytes; Antigens; Mesenchymal Stromal Cells; Osteoblasts; Periodontal Ligament

  12. Neural stem cell isolation and culture from C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    S Koirala

    2015-07-01

    Full Text Available INTRODUCTION A widely used in vitro culture, the neurosphere assay (NSA has provided a means to retrospectively identify neural progenitor cells as well as to determine both their selfrenewal capacity. Objective of study was to isolate and compare growth of the embryonic neuronal stem cell and adult neuronal stem cells in presence of Epidermal Growth Factor (EGF and Fibroblastic Growth Factor (FGF2. MATERIALS AND METHODS Embryonic neuronal stem cell were collected from cortical plate of dorsal telencephalon of fifteen C57BL/6 transgenic mice using stereoscopic microscope on 11th gestational day (GD. Adult mammalian neuronal stem cells taken from subventricular zone (SVZ of the lateral ventricles and subgranular layer of the dentate gyrus of the hippocampus were cultured. The growth for the neurosphere was then observed in interval of 24 and 72 hours. RESULT The adult stem cell culture showed few intact cells with high amount of debris and 9% heterogeneous sphere after 24 hours while only 20 % was observed at the end of 72 hours. Higher proliferation rate was observed in embryonic neurospheres than the adult stem cell culture. CONCLUSION Presence of EGF and basic FGF2 is essential for culture of neurospheres.DOI: http://dx.doi.org/10.3126/jcmsn.v10i2.12946 Journal of College of Medical Sciences-Nepal, 2014, Vol.10(2; 1-3

  13. Characterization and ethanol potential from giant cassava (Manihot esculenta) stem waste biomass

    Science.gov (United States)

    Septia, E.; Supriadi; Suwinarti, W.; Amirta, R.

    2018-04-01

    Manihot esculenta stem waste biomass is promising material for ethanol production since it is unutilized substance from cassava production. Nowadays, cassava is the most common food in Indonesian society. The aims of this study were to identify availability and characteristic of giant cassava (M. esculenta) stem waste biomass for ethanol feedstock. In term of that, four plots with the size of 5m x 5m were made to calculate the total stem biomass obtained after harvesting process. In this study, various concentrations of alkaline were used to degrade lignin from the substrate. The effects of alkaline pretreatment were investigated using TAPPI method and the ethanol yield was estimated using modified NREL protocol. The results showed that the potential dry stem waste biomass from harvesting of M. esculenta was approximately 10.5 ton/ha. Further, alkaline pretreatment of stem waste biomass with 2% of NaOH coupled with the enzymatic saccharification process using meicelase was showed the highest production of sugar to reach of 38.49 % of total reduction sugar and estimated potentially converted to 2,62 L/ha of ethanol. We suggested M. esculenta stem waste biomass could be used as sustainable feedstock for ethanol production in Indonesia.

  14. Maintenance of neural progenitor cell stemness in 3D hydrogels requires matrix remodelling

    Science.gov (United States)

    Madl, Christopher M.; Lesavage, Bauer L.; Dewi, Ruby E.; Dinh, Cong B.; Stowers, Ryan S.; Khariton, Margarita; Lampe, Kyle J.; Nguyen, Duong; Chaudhuri, Ovijit; Enejder, Annika; Heilshorn, Sarah C.

    2017-12-01

    Neural progenitor cell (NPC) culture within three-dimensional (3D) hydrogels is an attractive strategy for expanding a therapeutically relevant number of stem cells. However, relatively little is known about how 3D material properties such as stiffness and degradability affect the maintenance of NPC stemness in the absence of differentiation factors. Over a physiologically relevant range of stiffness from ~0.5 to 50 kPa, stemness maintenance did not correlate with initial hydrogel stiffness. In contrast, hydrogel degradation was both correlated with, and necessary for, maintenance of NPC stemness. This requirement for degradation was independent of cytoskeletal tension generation and presentation of engineered adhesive ligands, instead relying on matrix remodelling to facilitate cadherin-mediated cell-cell contact and promote β-catenin signalling. In two additional hydrogel systems, permitting NPC-mediated matrix remodelling proved to be a generalizable strategy for stemness maintenance in 3D. Our findings have identified matrix remodelling, in the absence of cytoskeletal tension generation, as a previously unknown strategy to maintain stemness in 3D.

  15. Stem and leaf anatomy of Plectranthus neochilus Schltr., Lamiaceae

    Directory of Open Access Journals (Sweden)

    Márcia do Rocio Duarte

    Full Text Available Plectranthus neochilus Schltr. is an aromatic herb named " boldo" or " boldo-gambá" and employed for treating hepatic insufficiency and dyspepsia in folk medicine. This paper has investigated its stem and leaf anatomy, in order to contribute for the medicinal plant identification. The botanical material was prepared according to standard microtechniques. The stem has quadrangular transection and, in secondary growth at the level analyzed, shows uniseriate epidermis and numerous trichomes. The glandular ones are capitate and peltate. The former has short unicellular or long multicellular stalk and uni- or bicellular head. The latter presents short stalk and eight-celled ovoid head. The non-glandular trichomes are multicellular, uniseriate and coated with granular cuticle. It is observed angular collenchyma, cambia forming phloem outward and xylem inward, and perivascular fiber caps next to the phloem. The blade has uniseriate epidermis coated with striate cuticle, diacytic stomata on both surfaces, numerous trichomes similar to the stem ones, and homogeneous mesophyll. The midrib shows one or two collateral bundles and the petiole has many of them distributed as an open arc.

  16. Induced pluripotent stem cells and their implication for regenerative medicine.

    Science.gov (United States)

    Csobonyeiova, Maria; Polak, Stefan; Koller, Jan; Danisovic, Lubos

    2015-06-01

    In 2006 Yamanaka's group showed that stem cells with properties similar to embryonic stem cells could be generated from mouse fibroblasts by introducing four genes. These cells were termed induced pluripotent stem cells (iPSCs). Because iPSCs avoid many of ethical concerns associated with the use of embryonic material, they have great potential in cell-based regenerative medicine. They are suitable also for other various purposes, including disease modelling, personalized cell therapy, drug or toxicity screening and basic research. Moreover, in the future, there might become possible to generate organs for human transplantation. Despite these progresses, several studies have raised the concern for genetic and epigenetic abnormalities of iPSCs that could contribute to immunogenicity of some cells differentiated from iPSCs. Recent methodological improvements are increasing the ease and efficacy of reprogramming, and reducing the genomic modification. However, to minimize or eliminate genetic alternations in the derived iPSC line creation, factor-free human iPSCs are necessary. In this review we discuss recent possibilities of using iPSCs for clinical applications and new advances in field of their reprogramming methods. The main goal of present article was to review the current knowledge about iPSCs and to discuss their potential for regenerative medicine.

  17. Endogenous Cartilage Repair by Recruitment of Stem Cells.

    Science.gov (United States)

    Im, Gun-Il

    2016-04-01

    Articular cartilage has a very limited capacity for repair after injury. The adult body has a pool of stem cells that are mobilized during injury or disease. These cells exist inside niches in bone marrow, muscle, adipose tissue, synovium, and other connective tissues. A method that mobilizes this endogenous pool of stem cells will provide a less costly and less invasive alternative if these cells successfully regenerate defective cartilage. Traditional microfracture procedures employ the concept of bone marrow stimulation to regenerate cartilage. However, the regenerated tissue usually is fibrous cartilage, which has very poor mechanical properties compared to those of normal hyaline cartilage. A method that directs the migration of a large number of autologous mesenchymal stem cells toward injury sites, retains these cells around the defects, and induces chondrogenic differentiation that would enhance success of endogenous cartilage repair. This review briefly summarizes chemokines and growth factors that induce recruitment, proliferation, and differentiation of endogenous progenitor cells, endogenous cell sources for regenerating cartilage, scaffolds for delivery of bioactive factors, and bioadhesive materials that are necessary to bring about endogenous cartilage repair.

  18. Guidance of mesenchymal stem cells on fibronectin structured hydrogel films.

    Directory of Open Access Journals (Sweden)

    Annika Kasten

    Full Text Available Designing of implant surfaces using a suitable ligand for cell adhesion to stimulate specific biological responses of stem cells will boost the application of regenerative implants. For example, materials that facilitate rapid and guided migration of stem cells would promote tissue regeneration. When seeded on fibronectin (FN that was homogeneously immmobilized to NCO-sP(EO-stat-PO, which otherwise prevents protein binding and cell adhesion, human mesenchymal stem cells (MSC revealed a faster migration, increased spreading and a more rapid organization of different cellular components for cell adhesion on fibronectin than on a glass surface. To further explore, how a structural organization of FN controls the behavior of MSC, adhesive lines of FN with varying width between 10 µm and 80 µm and spacings between 5 µm and 20 µm that did not allow cell adhesion were generated. In dependance on both line width and gaps, cells formed adjacent cell contacts, were individually organized in lines, or bridged the lines. With decreasing sizes of FN lines, speed and directionality of cell migration increased, which correlated with organization of the actin cytoskeleton, size and shape of the nuclei as well as of focal adhesions. Together, defined FN lines and gaps enabled a fine tuning of the structural organization of cellular components and migration. Microstructured adhesive substrates can mimic the extracellular matrix in vivo and stimulate cellular mechanisms which play a role in tissue regeneration.

  19. Stem cell biology and cell transplantation therapy in the retina.

    Science.gov (United States)

    Osakada, Fumitaka; Hirami, Yasuhiko; Takahashi, Masayo

    2010-01-01

    Embryonic stem (ES) cells, which are derived from the inner cell mass of mammalian blastocyst stage embryos, have the ability to differentiate into any cell type in the body and to grow indefinitely while maintaining pluripotency. During development, cells undergo progressive and irreversible differentiation into specialized adult cell types. Remarkably, in spite of this restriction in potential, adult somatic cells can be reprogrammed and returned to the naive state of pluripotency found in the early embryo simply by forcing expression of a defined set of transcription factors. These induced pluripotent stem (iPS) cells are molecularly and functionally equivalent to ES cells and provide powerful in vitro models for development, disease, and drug screening, as well as material for cell replacement therapy. Since functional impairment results from cell loss in most central nervous system (CNS) diseases, recovery of lost cells is an important treatment strategy. Although adult neurogenesis occurs in restricted regions, the CNS has poor potential for regeneration to compensate for cell loss. Thus, cell transplantation into damaged or diseased CNS tissues is a promising approach to treating various neurodegenerative disorders. Transplantation of photoreceptors or retinal pigment epithelium cells derived from human ES cells can restore some visual function. Patient-specific iPS cells may lead to customized cell therapy. However, regeneration of retinal function will require a detailed understanding of eye development, visual system circuitry, and retinal degeneration pathology. Here, we review the current progress in retinal regeneration, focusing on the therapeutic potential of pluripotent stem cells.

  20. Molecular Investigation of the Stem Snap Point in Textile Hemp

    Directory of Open Access Journals (Sweden)

    Marc Behr

    2017-12-01

    Full Text Available Fibre crops are important natural resources, as they sustainably provide bast fibres, an economically-valuable raw material used in the textile and biocomposite sectors. Among fibre crops, textile hemp (Cannabis sativa L. is appreciated for its long and strong gelatinous bast fibres. The stem of fibre crops is a useful system for cell wall-oriented studies, because it shows a strong tissue polarity with a lignified inner core and a cellulosic hypolignified cortex, as well as a basipetal lignification gradient. Along the stem axis of fibre crops, a specific region, denoted snap point, marks the transition from elongation (above it to fibre thickening (below it. After empirically determining the snap point by tilting the plant, we divided the stem segment containing it into three non-overlapping consecutive regions measuring 1 cm each, and carried out targeted RT-qPCR on cell wall-related genes separately, in outer and inner tissues. Different gene clusters can be observed, two of which are the major gene groups, i.e., one group with members expressed at higher levels in the inner tissues, and one group whose genes are more expressed in the cortex. The present results provide a molecular validation that the snap point is characterised by a gradient of events associated with the shift from fibre elongation to thickening.

  1. Stem cells and cancer: A review

    Directory of Open Access Journals (Sweden)

    Najeeb Ullah

    2016-05-01

    Full Text Available Stem cells are the small units of multicellular creature. Regeneration and self-renewal are the ability of the stem cells. Each tissue is having particular stem cells, specific to it. These normal stem cells are converted into cancer stem cells through mutations in it. Although the expression of oncogenes is enhanced a lot, the tumor-supressing gene is lessened. Cancer stem cells are isolated and visualized through different techniques like immunocytochemical staining, spectral karyotyping, immunohistochemistry, induction method and dissection measures, then are performed histological procedures which include fascination, immunohistochemistry, dispensation, in situ hybridization and also quantitative examination of tissue flow cytometric analysis. For the analysis of quantization, statistical tests are also performed as two-sample t-test, Chi-square test, SD and arithmetic mean. Tumor cells generate glioma spheres. These are used in cancer study. Axin 1 is the gene suppressing cancer. Its removal causes the generation of liver cancer. Curcumin is the most effective for suppressing cancer as it increases the normal stem cell function and decreases the cancer stem cell function. Brahma-related gene 1 is crucial for the safeguarding of the stem cell residents in tissue-specific comportment. Different types of cancers originate through genetic mutation, tissue disorganization and cell proliferation. Tumor configuration is produced by the alteration in original cell culture having stem cells and progenitor cell populations. The developmental facets about cancer cells and cancer stem cells as well as their personal natal functions sustain an intricate steadiness to settle on their personal donations to the efficacy or harmfulness of the biological organization.

  2. Zingiber zerumbet flower stem postharvest characterization

    Directory of Open Access Journals (Sweden)

    Charleston Gonçalves

    2017-05-01

    Full Text Available About the Zingiber zerumbet little is known about its cut flower postharvest and market, despite its high ornamental potential. The inflorescences, which resemble a compact cone, emerge from the base of the plants and start with green color changing to red with the age. This study objective was to characterize floral stem of ornamental ginger in two cultivate conditions and to evaluate the longevity of those submitted to post-harvest treatments. Flower stems were harvest from clumps cultivated under full sun and partial shade area, and were submitted to the postharvest treatments: complete flower immersion in tap water (CFI or only the base stem immersion (BSI. The flower stems harvested from clumps at partial shade presented higher fresh weight, length and diameter of the inflorescences compared to flower stems harvested from clumps at full sun area. The flower stem bracts cultivated in full sun area changed the color from green to red 10.69 and 11.94 days after BSI and CFI postharvest treatments, and the vase life were 22.94 and 28.19 days, respectively. Flower stem harvest in partial shade area change the color only after 18.94 and 18.43 days and the vase life durability was 27.56 and 31.81, respectively. The complete immersion of the flower stem increase the vase life durability in 5.25 and 4.25 days compared to flowers kept with the stem base immersed only, in flower stems harvested from clumps cultivated in full sun area and partial shade area, respectively. Flower stems harvested from clumps cultivated in partial shade area and completely immerse in tap water during 3 hours increase the vase life durability in 8.87 days compared to flowers harvested from clumps cultivated in full sun area and base immersed only.

  3. Stem Cells for Skeletal Muscle Tissue Engineering.

    Science.gov (United States)

    Pantelic, Molly N; Larkin, Lisa M

    2018-04-19

    Volumetric muscle loss (VML) is a debilitating condition wherein muscle loss overwhelms the body's normal physiological repair mechanism. VML is particularly common among military service members who have sustained war injuries. Because of the high social and medical cost associated with VML and suboptimal current surgical treatments, there is great interest in developing better VML therapies. Skeletal muscle tissue engineering (SMTE) is a promising alternative to traditional VML surgical treatments that use autogenic tissue grafts, and rather uses isolated stem cells with myogenic potential to generate de novo skeletal muscle tissues to treat VML. Satellite cells are the native precursors to skeletal muscle tissue, and are thus the most commonly studied starting source for SMTE. However, satellite cells are difficult to isolate and purify, and it is presently unknown whether they would be a practical source in clinical SMTE applications. Alternative myogenic stem cells, including adipose-derived stem cells, bone marrow-derived mesenchymal stem cells, perivascular stem cells, umbilical cord mesenchymal stem cells, induced pluripotent stem cells, and embryonic stem cells, each have myogenic potential and have been identified as possible starting sources for SMTE, although they have yet to be studied in detail for this purpose. These alternative stem cell varieties offer unique advantages and disadvantages that are worth exploring further to advance the SMTE field toward highly functional, safe, and practical VML treatments. The following review summarizes the current state of satellite cell-based SMTE, details the properties and practical advantages of alternative myogenic stem cells, and offers guidance to tissue engineers on how alternative myogenic stem cells can be incorporated into SMTE research.

  4. Hypoxic Preconditioning Promotes the Bioactivities of Mesenchymal Stem Cells via the HIF-1?-GRP78-Akt Axis

    OpenAIRE

    Lee, Jun Hee; Yoon, Yeo Min; Lee, Sang Hun

    2017-01-01

    Mesenchymal stem cells (MSC) are ideal materials for stem cell-based therapy. As MSCs reside in hypoxic microenvironments (low oxygen tension of 1% to 7%), several studies have focused on the beneficial effects of hypoxic preconditioning on MSC survival; however, the mechanisms underlying such effects remain unclear. This study aimed to uncover the potential mechanism involving 78-kDa glucose-regulated protein (GRP78) to explain the enhanced MSC bioactivity and survival in hindlimb ischemia. ...

  5. Stem Cells: What They Are and What They Do

    Science.gov (United States)

    Stem cells: What they are and what they do Stem cells and derived products offer great promise for new medical treatments. Learn about stem cell types, current and possible uses, ethical issues, and ...

  6. Stem Cell Research: Unlocking the Mystery of Disease

    Science.gov (United States)

    ... Home Current Issue Past Issues From the Director: Stem Cell Research: Unlocking the Mystery of Disease Past Issues / ... Zerhouni, NIH Director, described the need for expanding stem cell research. Recently, he spoke about stem cell research ...

  7. Amniotic fluid-derived mesenchymal stem cells as a novel ...

    African Journals Online (AJOL)

    CLEMENTINA

    2012-06-28

    Jun 28, 2012 ... stem cells (AFMSCs) have many advantages over other stem cells: avoiding much ethical controversy ... showed that induced pluripotent stem cells (iPSCs) have ... disadvantages of ESCs, BM-MSCs and iPSCs have.

  8. Efficient cryopreservation of human pluripotent stem cells by surface-based vitrification

    NARCIS (Netherlands)

    Neubauer, Julia C; Beier, Axel F; Geijsen, Niels; Zimmermann, Heiko

    2015-01-01

    Efficient cryopreservation of human stem cells is crucial for guaranteeing a permanent supply of high-quality cell material for drug discovery or regenerative medicine. Conventionally used protocols usually employing slow freezing rates, however, result in low recovery rates for human pluripotent

  9. AEM/STEM analysis of vapor-deposited multilayered laser targets

    International Nuclear Information System (INIS)

    Johnson, K.A.; Staudhammer, K.P.; Reeves, G.A.; Vesser, L.R.

    1983-01-01

    S(TEM) examinations were made to augment other types of measurements of absolute density. The structure of the 5 μm thick layers of aluminum and gold on aluminum laminate gold substrate was examined to establish film integrity, to characterize the microstructure, as well as to estimate the surface roughness of this multilayer material

  10. Cloning, Stem Cells, and the Current National Debate: Incorporating Ethics into a Large Introductory Biology Course

    Science.gov (United States)

    Fink, Rachel D.

    2002-01-01

    Discussing the ethical issues involved in topics such as cloning and stem cell research in a large introductory biology course is often difficult. Teachers may be wary of presenting material biased by personal beliefs, and students often feel inhibited speaking about moral issues in a large group. Yet, to ignore what is happening "out there"…

  11. Finite element analysis of stemming loads on pipes

    International Nuclear Information System (INIS)

    Maiden, D.E.

    1979-08-01

    A computational model has been developed for calculating the loads and displacements on a pipe placed in a hole which is subsequently filled with soil. A composite soil-pipe finite element model which employs fundamental material constants in its formalism is derived. The shear modulus of the soil, and the coefficient of friction at the pipe are the important constants to be specified. The calculated loads on the pipe are in agreement with experimental data for layered and unlayered stemming designs. As a result more economical designs of the pipe string can be realized

  12. Using Recreational Drones to Promote STEM Learning

    Science.gov (United States)

    Olds, S. E.; Dahlman, L. E.; Mooney, M. E.; Russell, R. M.

    2017-12-01

    The popularity of unmanned aerial vehicles (UAVs or drones) as a fun, inexpensive (website (SciEd.ucar.edu/engineering-activities), the activities encompass skills to measure drone payload, flight height, and velocity. Investigations also encourage the use of repeat photography, comparing images from drones and satellites, and creating 3D structure from motion (SfM) models from overlapping photographs. The site also offers general guidance to develop science projects or science fair investigations using Next Generation Science Standards science and engineering practices. To encourage the use of drones in STEM, UNAVCO and NOAA staff, sponsored by ESIP, led two hands-on workshops this summer; a three half-day workshop at the Earth Educator Rendezvous (EER) and a half-day session during the ESIP Educator Workshop. Participants practiced UAV flying skills, experimented with lightweight sensors, and learned about current drone-enhanced research projects. In small groups, they tested existing activities and designed student-focused investigations. Examples of projects include measuring aeromagnetics, developing 3D topographic models, creating vertical profiles over various land-surfaces at different temporal intervals, and developing a multi-semester drone-focused curriculum. This presentation will elaborate upon the workshops, learning materials, and insights.

  13. Nuclear materials

    International Nuclear Information System (INIS)

    1996-01-01

    In 1998, Nuclear Regulatory Authority of the Slovak Republic (NRA SR) performed 38 inspections, 25 of them were performed in co-operation with IAEA inspectors. There is no fresh nuclear fuel at Bohunice A-1 NPP at present. Fresh fuel of Bohunice V-1 and V-2 NPPs is inspected in the fresh fuel storage.There are 327 fresh fuel assemblies in Mochovce NPP fresh fuel storage. In addition to that, are also 71 small users of nuclear materials in Slovakia. In most cases they use: covers made of depleted uranium for non-destructive works, detection of level in production plants, covers for therapeutical sources at medical facilities. In. 1995, NRA SR issued 4 new licences for nuclear material withdrawal. In the next part manipulation with nuclear materials, spent fuel stores and illegal trafficking in nuclear materials are reported

  14. Composite Materials

    DEFF Research Database (Denmark)

    Nielsen, Lauge Fuglsang

    This book deals with the mechanical and physical behavior of composites as influenced by composite geometry. "Composite Materials" provides a comprehensive introduction for researchers and students to modern composite materials research with a special emphasis on the significance of phase geometry......, viscoelastic behavior, and internal stress states. Other physical properties considered are thermal and electrical conductivities, diffusion coefficients, dielectric constants and magnetic permeability. Special attention is given to the effect of pore shape on the mechanical and physical behavior of porous....... The book enables the reader to a better understanding of the behavior of natural composites, improvement of such materials, and design of new materials with prescribed properties. A number of examples are presented: Special composite properties considered are stiffness, shrinkage, hygro-thermal behavior...

  15. Hazardous materials

    Science.gov (United States)

    ... substances that could harm human health or the environment. Hazardous means dangerous, so these materials must be ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  16. Utopian Materialities

    DEFF Research Database (Denmark)

    Elgaard-Jensen, Torben

    2004-01-01

    In various ways, this paper makes the counter-intuitive claim that the utopian and the material are thoroughlyinterdependent, rather than worlds apart. First, through a reading of Thomas More's Utopia, it is argued thatUtopia is the product of particular kinds of relations, rather than merely...... a detachment from the known world.Second, the utopianism of a new economy firm is examined. It is argued that the physical set-up of the firm -in particular the distribution of tables and chairs - evoke a number of alternatives to ordinary work practice.In this way the materialities of the firm are crucial...... to its persuasive image of being the office of the future.The notion that utopia is achieved through material arrangements is finally related to the analysis of facts andfictions in ANT. It is argued, that even though Utopias are neither fact nor fiction, they are both material andeffective...

  17. Stem cell therapy for intervertebral disc regeneration: review article

    Directory of Open Access Journals (Sweden)

    Mohsen Sheykhhasan

    2017-02-01

    Full Text Available Intervertebral disks (IVD acts as shock absorber between each of the vertebrae in the spinal column by keeping the vertebrae separated when the shock caused by the action. They also serve to protect the nerves that run down the middle of the spine and intervertebral disks. The disks are made of fibrocartilaginous material. The outside of the disk is made of a strong material called the annulus fibrosus. Inside this protective covering is a jelly-like substance known as mucoprotein gel. This interior is known as the nucleus pulposus. The nucleus pulposus consists of large vacuolated notochord cells, small chondrocyte-like cells, collagen fibrils, and aggrecan, a proteoglycan that aggregates by binding to hyaluronan. Attached to each aggrecan molecule are glycosaminoglycan (GAG chains of chondroitin sulfate and keratan sulfate. Intervertebral disks degeneration is frequently associated with low back and neck pain, which accounts as a disability. Despite the known outcomes of the Intervertebral disks degeneration cascade, the treatment of IVD degeneration is limited in that available conservative and surgical treatments do not reverse the pathology or restore the IVD tissue. Regenerative medicine for IVD degeneration, by injection of Intervertebral disks cells, chondrocytes or stem cells, has been extensively studied in the past decade in various animal models of induced IVD degeneration, and has progressed to clinical trials in the treatment of various spinal disease. Despite preliminary results showing positive effects of cell-injection strategies for IVD regeneration, detailed basic research on Intervertebral disks cells and their niche demonstrates that transplanted cells are unable to survive and adapt in the avascular niche of the IVD. For this therapeutic strategy to succeed, the indications for its use and the patients who would benefit need to be better defined. To surmount these obstacles, the solution will be identified only by focused

  18. Mesenchymal Stem Cells in Cardiology

    Science.gov (United States)

    White, Ian A.; Sanina, Cristina; Balkan, Wayne; Hare, Joshua M.

    2017-01-01

    Cardiovascular disease (CVD) accounts for more deaths globally than any other single disease. There are on average 1.5 million episodes of myocardial infarction (heart attack) each year in the United States alone with roughly one third resulting in death. There is therefore a major need for developing new and effective strategies to promote cardiac repair. Intramyocardial transplantation of mesenchymal stem cells (MSCs) has emerged as a leading contender in the pursuit of clinical intervention and therapy. MSCs are potent mediators of cardiac repair and are therefore an attractive tool in the development of pre-clinical and clinical trials. MSCs are capable of secreting a large array of soluble factors, which have had demonstrated effects on pathogenic cardiac remolding, fibrosis, immune activation and cardiac stem cell proliferation within the damaged heart. MSCs are also capable of differentiation into cardiomyocytes, endothelial cells and vascular smooth muscle cells, although the relative contribution of trilineage differentiation and paracrine effectors on cardiac repair remains the subject of active investigation. PMID:27236666

  19. Propulsion materials

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Edward J. [U.S. Dept. of Energy, Washington, D.C. (United States); Sullivan, Rogelio A. [U.S. Dept. of Energy, Washington, D.C. (United States); Gibbs, Jerry L. [U.S. Dept. of Energy, Washington, D.C. (United States)

    2008-01-01

    The Department of Energy’s (DOE’s) Office of Vehicle Technologies (OVT) is pleased to introduce the FY 2007 Annual Progress Report for the Propulsion Materials Research and Development Program. Together with DOE national laboratories and in partnership with private industry and universities across the United States, the program continues to engage in research and development (R&D) that provides enabling materials technology for fuel-efficient and environmentally friendly commercial and passenger vehicles.

  20. Encountering Materiality

    DEFF Research Database (Denmark)

    Svabo, Connie

    2016-01-01

    DHT researcher Connie Svabo and artist Charlotte Grum did a joint performance presentation titled Becoming Sheep, Becoming Animal at the international conference Encountering Materiality – Transdisciplinary Conversations, held in Geneve, Schwitzerland, June 23-25 2016.......DHT researcher Connie Svabo and artist Charlotte Grum did a joint performance presentation titled Becoming Sheep, Becoming Animal at the international conference Encountering Materiality – Transdisciplinary Conversations, held in Geneve, Schwitzerland, June 23-25 2016....

  1. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  2. Engineered Biomaterials to Enhance Stem Cell-Based Cardiac Tissue Engineering and Therapy.

    Science.gov (United States)

    Hasan, Anwarul; Waters, Renae; Roula, Boustany; Dana, Rahbani; Yara, Seif; Alexandre, Toubia; Paul, Arghya

    2016-07-01

    Cardiovascular disease is a leading cause of death worldwide. Since adult cardiac cells are limited in their proliferation, cardiac tissue with dead or damaged cardiac cells downstream of the occluded vessel does not regenerate after myocardial infarction. The cardiac tissue is then replaced with nonfunctional fibrotic scar tissue rather than new cardiac cells, which leaves the heart weak. The limited proliferation ability of host cardiac cells has motivated investigators to research the potential cardiac regenerative ability of stem cells. Considerable progress has been made in this endeavor. However, the optimum type of stem cells along with the most suitable matrix-material and cellular microenvironmental cues are yet to be identified or agreed upon. This review presents an overview of various types of biofunctional materials and biomaterial matrices, which in combination with stem cells, have shown promises for cardiac tissue replacement and reinforcement. Engineered biomaterials also have applications in cardiac tissue engineering, in which tissue constructs are developed in vitro by combining stem cells and biomaterial scaffolds for drug screening or eventual implantation. This review highlights the benefits of using biomaterials in conjunction with stem cells to repair damaged myocardium and give a brief description of the properties of these biomaterials that make them such valuable tools to the field. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Мodification of Mechanical Limbal Stem Cell Deficiency Model

    Directory of Open Access Journals (Sweden)

    A. V. Bezushko

    2018-01-01

    Full Text Available Introduction. Ocular surface diseases related with limbal epithelial stem cells dysfunction were united in term “limbal stem cell  deficiency” (LSCD. For experimental study of the regenerative processes and evaluation of the success of new LSCD treatingmethods LSCD model is required. Various LSCD models were proposed in the experiment to study: mechanical, thermal, chemical,medicamental. The main lack of these models were the relative high cost and complexity of execution. The mechanical model allows forthe guaranteed removal of tissues containing LESCs, and therefore seems to be the most acceptable. We offered a modification of themechanical LSCD model in rabbits. Purpose to create a standardized modification of the mechanical limbal stem cell deficiency modelin the experiment. Material and methods. The experimental study was performed in 10 mature Chinchilla rabbits (20 eyes with anaverage weight 2.5–3.5 kg. With the local anesthesia, after a 40-second application of the filter paper impregnated with 20% ethanol,the corneal epithelium was removed. With microsurgical diamond blade we metered limb portion of 4 mm width, 0.2 mm deep, andit was removed along the 360° rim. Results. On the 30th day we discovered corneal opacity and neovascularization with conjunctivalpannus extending to the optical zone of the cornea. Histological examination revealed tissue edema, inflammatory infiltration, andnewly formed vessels. In some places, thinning of epithelium to one row of flattened cells was observed. The Bowman membrane wasdeformed and practically not detected. Histological examination and impression cytology confirmed the presence of goblet cells in thecorneal epithelium. Conclusions. Our modification of the mechanical limbal stem cell deficiency model is devoid of the main lacks ofprevious models, such as the high cost and complexity of execution, provides intraoperative limbal tissue resection depth control andexcludes the possibility of the

  4. Measured air overpressures, soil-particle pressures, and slumps during the pre-ASIAGO U2Ar stemming experiment

    Energy Technology Data Exchange (ETDEWEB)

    Freynik, H.S. Jr.; Roach, D.R.; Dittbenner, G.R.

    1978-01-04

    On November 15, 1976, Lawrence Livermore Laboratory completed its first comprehensive stemming experiment for measuring downhole parameters while varying fill material and rate. Stemming can be defined as backfilling a hole in which a device has been placed to prevent leakage of radioactive materials or gases to the surface. A computer code is being developed for stemming operations, and this experiment was designed to measure parameters under different stemming conditions so the code could be verified and modified. The experiment was conducted in the lower half of a steel-cased, 4-ft-diam, 2000-ft-deep hole at Nevada Test Site. The two stemming materials used in the experiment, Overton sand and LLL II mix, were tested at three fill rates. Significant results of this experiment included successful measurement of downhole air overpressures, vertical and horizontal soil-particle pressures, and temperature. Vertical soil-particle pressures were higher than expected. All surface measurements were valid. The slump-displacement measurements system provided a timing mark to indicate the occurrence of a slump. A major slump occurred on the third day of stemming; a minor slump occurred on the fourth day.

  5. Measured air overpressures, soil-particle pressures, and slumps during the pre-ASIAGO U2Ar stemming experiment

    International Nuclear Information System (INIS)

    Freynik, H.S. Jr.; Roach, D.R.; Dittbenner, G.R.

    1978-01-01

    On November 15, 1976, Lawrence Livermore Laboratory completed its first comprehensive stemming experiment for measuring downhole parameters while varying fill material and rate. Stemming can be defined as backfilling a hole in which a device has been placed to prevent leakage of radioactive materials or gases to the surface. A computer code is being developed for stemming operations, and this experiment was designed to measure parameters under different stemming conditions so the code could be verified and modified. The experiment was conducted in the lower half of a steel-cased, 4-ft-diam, 2000-ft-deep hole at Nevada Test Site. The two stemming materials used in the experiment, Overton sand and LLL II mix, were tested at three fill rates. Significant results of this experiment included successful measurement of downhole air overpressures, vertical and horizontal soil-particle pressures, and temperature. Vertical soil-particle pressures were higher than expected. All surface measurements were valid. The slump-displacement measurements system provided a timing mark to indicate the occurrence of a slump. A major slump occurred on the third day of stemming; a minor slump occurred on the fourth day

  6. Generation of hematopoietic stem cells from human embryonic stem cells using a defined, stepwise, serum-free, and serum replacement-free monolayer culture method.

    Science.gov (United States)

    Kim, So-Jung; Jung, Ji-Won; Ha, Hye-Yeong; Koo, Soo Kyung; Kim, Eung-Gook; Kim, Jung-Hyun

    2017-03-01

    Embryonic stem cells (ESCs) can be expanded infinitely in vitro and have the potential to differentiate into hematopoietic stem cells (HSCs); thus, they are considered a useful source of cells for HSC production. Although several technical in vitro methods for engineering HSCs from pluripotent stem cells have been developed, clinical application of HSCs engineered from pluripotent stem cells is restricted because of the possibility of xenogeneic contamination resulting from the use of murine materials. Human ESCs (CHA-hES15) were cultured on growth factor-reduced Matrigel-coated dishes in the mTeSR1 serum-free medium. When the cells were 70% confluent, we initiated HSC differentiation by three methods involving (1) knockout serum replacement (KSR), cytokines, TGFb1, EPO, and FLT3L; (2) KSR, cytokines, and bFGF; or (3) cytokines and bFGF. Among the three differentiation methods, the minimal number of cytokines without KSR resulted in the greatest production of HSCs. The optimized method resulted in a higher proportion of CD34 + CD43 + hematopoietic progenitor cells (HPCs) and CD34 + CD45 + HPCs compared to the other methods. In addition, the HSCs showed the potential to differentiate into multiple lineages of hematopoietic cells in vitro . In this study, we optimized a two-step, serum-free, animal protein-free, KSR-free, feeder-free, chemically defined monolayer culture method for generation of HSCs and hematopoietic stem and progenitor cells (HSPCs) from human ESCs.

  7. In vitro evaluation of isolation possibility of stem cells from intra oral soft tissue and comparison of them with bone mar-row stem cells

    Directory of Open Access Journals (Sweden)

    P. Torkzaban

    2012-01-01

    Full Text Available Objective: Stem cells are of great interest for regenerating disturbed tissues and organs. These cells are commonly isolated from the bone marrow, but there has been interest in other tissues in the recent years. In this study, we evaluated the possibility of isolation of stem cells from oral connective tissue and investigated their characteristics.Materials and Methods: In this experimental study, sampling from the bone marrow and oral connective tissue of a beagle dog was performed under general anesthesia. Bone marrow stem cell isolation was performed according to the established protocols. The samples obtained from oral soft tissue were broken to small pieces and after adding collagenase I, the samples were incubated for 45 minutes in 37°C. Other processes were similar to the processes which were carried out on bone marrow cells. Then cell properties were compared to evaluate if the cells from the connective tissue were stem cells.Results: The cells from the bone marrow and connective tissue had the same morphology. The result of colony forming unit assay was relatively similar. Population doubling time was similar too. In addition, both cell groups differentiated to osteoblasts in osteogenic media.Conclusion: The cells isolated from the oral connective tissue had the characteristics of stem cells, including fibroblastoid morphology, self renewal properties, high proliferation rate and differentiation potential.

  8. Mathematical Modeling: A Bridge to STEM Education

    Science.gov (United States)

    Kertil, Mahmut; Gurel, Cem

    2016-01-01

    The purpose of this study is making a theoretical discussion on the relationship between mathematical modeling and integrated STEM education. First of all, STEM education perspective and the construct of mathematical modeling in mathematics education is introduced. A review of literature is provided on how mathematical modeling literature may…

  9. Stem cell treatment of degenerative eye disease

    Directory of Open Access Journals (Sweden)

    Ben Mead

    2015-05-01

    Full Text Available Stem cell therapies are being explored extensively as treatments for degenerative eye disease, either for replacing lost neurons, restoring neural circuits or, based on more recent evidence, as paracrine-mediated therapies in which stem cell-derived trophic factors protect compromised endogenous retinal neurons from death and induce the growth of new connections. Retinal progenitor phenotypes induced from embryonic stem cells/induced pluripotent stem cells (ESCs/iPSCs and endogenous retinal stem cells may replace lost photoreceptors and retinal pigment epithelial (RPE cells and restore vision in the diseased eye, whereas treatment of injured retinal ganglion cells (RGCs has so far been reliant on mesenchymal stem cells (MSC. Here, we review the properties of non-retinal-derived adult stem cells, in particular neural stem cells (NSCs, MSC derived from bone marrow (BMSC, adipose tissues (ADSC and dental pulp (DPSC, together with ESC/iPSC and discuss and compare their potential advantages as therapies designed to provide trophic support, repair and replacement of retinal neurons, RPE and glia in degenerative retinal diseases. We conclude that ESCs/iPSCs have the potential to replace lost retinal cells, whereas MSC may be a useful source of paracrine factors that protect RGC and stimulate regeneration of their axons in the optic nerve in degenerate eye disease. NSC may have potential as both a source of replacement cells and also as mediators of paracrine treatment.

  10. Service Learning and STEM Education Design

    Directory of Open Access Journals (Sweden)

    Parichart Prasertsang

    2017-06-01

    Full Text Available Community service allowed learners to meet their real Competency in leadership classroom. Thinking and doing by problem Solving togethers among learners, teacher, and Community seem to be STEM education. It aimed to create and innovate thing for supporting Community. STEM education as a final stage that meet service learning and community based knowledge.

  11. Students' Attitude towards STEM Education

    Science.gov (United States)

    Popa, Roxana-Alexandra; Ciascai, Liliana

    2017-01-01

    STEM is the acronym of Science, Technology, Engineering, and Mathematics fields. STEM education refers both to teaching and learning in the above-mentioned disciplines, but especially to teaching and learning a new discipline based on the integration of Science, Technology, Engineering, and Mathematics. The present survey aims to investigate the…

  12. Preparation Matters Most in STEM. Issue Brief

    Science.gov (United States)

    Hayes, Shannon

    2017-01-01

    Serious attention has been directed in recent years towards the need for increasing the number of high school graduates in the United States who are prepared for postsecondary education, training and careers in the fields of science, technology, engineering, and mathematics (STEM). The number of jobs in U.S. STEM occupations grew by 10.5 percent…

  13. Universities Conducting STEM Outreach: A Conceptual Framework

    Science.gov (United States)

    Eilam, Efrat; Bigger, Stephen W.; Sadler, Kirsten; Barry, Fiachra; Bielik, Tom

    2016-01-01

    This paper addresses the positioning of science, technology, engineering and mathematics (STEM) outreach programmes within universities' operations. Though universities in many respects form a rather homogenous international community, there is wide diversity in regard to the provision of STEM outreach by different institutions. To explain this…

  14. STEM Education for Girls of Color

    Science.gov (United States)

    Yee, Kam H.

    Science, technology, engineering, and math (STEM) fields struggle to increase recruitment and retention of girls of color. The dominant framework in STEM education is the pipeline which assumes girls in general lack motivation and interest to persist in STEM fields. Recent public discourse shifts to address institutionalized discrimination and systemic barriers in STEM culture that filter out underrepresented populations. Informal education or complementary learning STEM programs offer alternative opportunities for students to explore outside of rigid school academic and social systems. Few articles look specifically at STEM complementary learning programs, and even fewer focus on the effects on girls of color. This research is a quantitative study to categorize existing mission statements and training behind organizations that provide STEM programs. The results will provide a better understanding of the relationship between practices of STEM education organizations and the programs they create. Diversity training and inclusive language in mission statements had weak correlations with increased cultural responsiveness in the program offerings. The results suggest organizations must be more intentional and explicit when implementing diversity goals.

  15. Physiology of stem cell-derived cardiomyocytes

    NARCIS (Netherlands)

    Boer, T.P. de

    2007-01-01

    All chapters in this thesis revolve around the general theme, stem cells and their electrophysiological characteristics and capacity to induce pro-arrhythmia. The first part of this thesis focusses on key aspects that are relevant to possible pro-arrhythmic effects of stem cell transplantation. An

  16. Stem Cell Research and Health Education

    Science.gov (United States)

    Eve, David J.; Marty, Phillip J.; McDermott, Robert J.; Klasko, Stephen K.; Sanberg, Paul R.

    2008-01-01

    Stem cells are being touted as the greatest discovery for the potential treatment of a myriad of diseases in the new millennium, but there is still much research to be done before it will be known whether they can live up to this description. There is also an ethical debate over the production of one of the most valuable types of stem cell: the…

  17. Cerebral toxoplasmosis after haematopoietic stem cell transplantation

    Directory of Open Access Journals (Sweden)

    Agnieszka Zaucha-Prażmo

    2017-05-01

    Full Text Available Toxoplasmosis is an opportunistic infection caused by the parasite Toxoplasma gondii. The infection is severe and difficult to diagnose in patients receiving allogeneic haematopoietic stem cell transplantation (HSCT. It frequently involves the central nervous system. The case is presented of cerebral toxoplasmosis in a 17-year-old youth with Fanconi anaemia treated with haematopoietic stem cell transplantation (HSCT

  18. Symposium Promotes Technological Literacy through STEM

    Science.gov (United States)

    Havice, Bill; Marshall, Jerry

    2009-01-01

    This article describes a symposium which promotes technological literacy through science, technology, engineering, and mathematics (STEM). The three-day symposium titled, "The Anderson, Oconee, Pickens Symposium on Teaching and Learning STEM Standards for the 21st Century," was held August 4-6, 2008 at the Tri-County Technical College…

  19. Determination of the pipe stemming load

    International Nuclear Information System (INIS)

    Cowin, S.C.

    1979-01-01

    A mechanical model for the emplacement pipe system is developed. The model is then employed to determine the force applied to the surface collar of the emplacement pipe, the pipe-stemming load, and the stress along the emplacement pipe as a function of stemming height. These results are presented as integrals and a method for their numerical integration is given

  20. Pathological modifications of plant stem cell destiny

    Science.gov (United States)

    In higher plants, the shoot apex contains undifferentiated stem cells that give rise to various tissues and organs. The fate of these stem cells determines the pattern of plant growth as well as reproduction; and such fate is genetically preprogrammed. We found that a bacterial infection can derai...

  1. Stem Cells, Science, and Public Reasoning

    Science.gov (United States)

    Hurlbut, J. Benjamin; Robert, Jason Scott

    2012-01-01

    These are interesting days in the scientific, social, and political debates about human embryonic stem cell research. Pluripotent stem cells--cells that can, in principle, give rise to the body's full range of cell types--were previously derivable only from human embryos that were destroyed in the process. Now, a variety of somatic cell types can…

  2. STEM Leadership Qualification: Tomorrow's Leaders Today

    Science.gov (United States)

    Williams, Chris

    2009-01-01

    This article features the Science, Technology, Engineering and Mathematics (STEM) Leadership Qualification programme, developed by the Centre for Science Education (CSE) at Sheffield Hallam University in collaboration with Edexcel, which sets out to develop leadership skills and capabilities through contexts in STEM. With six units to complete…

  3. Stem Cell Transplants in Cancer Treatment

    Science.gov (United States)

    Stem cell transplants are procedures that restore blood-forming stem cells in cancer patients who have had theirs destroyed by very high doses of chemotherapy or radiation therapy. Learn about the types of transplants and side effects that may occur.

  4. Representations of stem cell clinics on Twitter.

    Science.gov (United States)

    Kamenova, Kalina; Reshef, Amir; Caulfield, Timothy

    2014-12-01

    The practice of travelling abroad to receive unproven and unregulated stem cell treatments has become an increasingly problematic global phenomenon known as 'stem cell tourism'. In this paper, we examine representations of nine major clinics and providers of such treatments on the microblogging network Twitter. We collected and conducted a content analysis of Twitter posts (n = 363) by these establishments and by other users mentioning them, focusing specifically on marketing claims about treatment procedures and outcomes, discussions of safety and efficacy of stem cell transplants, and specific representations of patients' experiences. Our analysis has shown that there were explicit claims or suggestions of benefits associated with unproven stem cell treatments in approximately one third of the tweets and that patients' experiences, whenever referenced, were presented as invariably positive and as testimonials about the efficacy of stem cell transplants. Furthermore, the results indicated that the tone of most tweets (60.2 %) was overwhelmingly positive and there were rarely critical discussions about significant health risks associated with unproven stem cell therapies. When placed in the context of past research on the problems associated with the marketing of unproven stem cell therapies, this analysis of representations on Twitter suggests that discussions in social media have also remained largely uncritical of the stem cell tourism phenomenon, with inaccurate representations of risks and benefits for patients.

  5. Stem cells in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Seong, Jeong Min [Department of Preventive and Social Dentistry and Institute of Oral Biology, College of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Kim, Byung-Chul; Park, Jae-Hong; Kwon, Il Keun; Hwang, Yu-Shik [Department of Maxillofacial Biomedical Engineering and Institute of Oral Biology, College of Dentistry, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Mantalaris, Anathathios, E-mail: yshwang@khu.ac.k [Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom)

    2010-12-15

    Bone tissue engineering has been one of the most promising areas of research, providing a potential clinical application to cure bone defects. Recently, various stem cells including embryonic stem cells (ESCs), bone marrow-derived mesenchymal stem cells (BM-MSCs), umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), adipose tissue-derived stem cells (ADSCs), muscle-derived stem cells (MDSCs) and dental pulp stem cells (DPSCs) have received extensive attention in the field of bone tissue engineering due to their distinct biological capability to differentiate into osteogenic lineages. The application of these stem cells to bone tissue engineering requires inducing in vitro differentiation of these cells into bone forming cells, osteoblasts. For this purpose, efficient in vitro differentiation towards osteogenic lineage requires the development of well-defined and proficient protocols. This would reduce the likelihood of spontaneous differentiation into divergent lineages and increase the available cell source for application to bone tissue engineering therapies. This review provides a critical examination of the various experimental strategies that could be used to direct the differentiation of ESC, BM-MSC, UCB-MSC, ADSC, MDSC and DPSC towards osteogenic lineages and their potential applications in tissue engineering, particularly in the regeneration of bone. (topical review)

  6. STEM Education in Canada: A Knowledge Synthesis

    Science.gov (United States)

    DeCoito, Isha

    2016-01-01

    Across Canada many initiatives have been initiated to generate more interest in science, technology, engineering, and mathematics (STEM) education; however, no single or comprehensive overview has been conducted that takes into account the impact of these STEM initiatives on teaching/learning outcomes in K-12 education. This knowledge synthesis of…

  7. Psychosocial Factors Impacting STEM Career Selection

    Science.gov (United States)

    Lamb, Richard; Annetta, Leonard; Vallett, David; Firestone, Jonah; Schmitter-Edgecombe, Maureen; Walker, Heather; Deviller, Nicole; Hoston, Douglas

    2018-01-01

    Attention on P-20 science, technology, engineering, and mathematics (STEM) education has increased tremendously in recent years. Many efforts are underway to promote STEM major and career selection across the nation; specifically, in engineering and computer science. The authors' purpose was to examine an underlying profile combinations of latent…

  8. Stem cells in bone tissue engineering

    International Nuclear Information System (INIS)

    Seong, Jeong Min; Kim, Byung-Chul; Park, Jae-Hong; Kwon, Il Keun; Hwang, Yu-Shik; Mantalaris, Anathathios

    2010-01-01

    Bone tissue engineering has been one of the most promising areas of research, providing a potential clinical application to cure bone defects. Recently, various stem cells including embryonic stem cells (ESCs), bone marrow-derived mesenchymal stem cells (BM-MSCs), umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs), adipose tissue-derived stem cells (ADSCs), muscle-derived stem cells (MDSCs) and dental pulp stem cells (DPSCs) have received extensive attention in the field of bone tissue engineering due to their distinct biological capability to differentiate into osteogenic lineages. The application of these stem cells to bone tissue engineering requires inducing in vitro differentiation of these cells into bone forming cells, osteoblasts. For this purpose, efficient in vitro differentiation towards osteogenic lineage requires the development of well-defined and proficient protocols. This would reduce the likelihood of spontaneous differentiation into divergent lineages and increase the available cell source for application to bone tissue engineering therapies. This review provides a critical examination of the various experimental strategies that could be used to direct the differentiation of ESC, BM-MSC, UCB-MSC, ADSC, MDSC and DPSC towards osteogenic lineages and their potential applications in tissue engineering, particularly in the regeneration of bone. (topical review)

  9. Hematopoietic stem cell expansion : challenges and opportunities

    NARCIS (Netherlands)

    Walasek, Marta A.; van Os, Ronald; de Haan, Gerald; Kanz, L; Fibbe, WE; Lengerke, C; Dick, JE

    2012-01-01

    Attempts to improve hematopoietic reconstitution and engraftment potential of ex vivo-expanded hematopoietic stem and progenitor cells (HSPCs) have been largely unsuccessful due to the inability to generate sufficient stem cell numbers and to excessive differentiation of the starting cell

  10. Molecular regulation of human hematopoietic stem cells

    NARCIS (Netherlands)

    van Galen, P.L.J.

    2014-01-01

    Peter van Galen focuses on understanding the determinants that maintain the stem cell state. Using human hematopoietic stem cells (HSCs) as a model, processes that govern self-renewal and tissue regeneration were investigated. Specifically, a role for microRNAs in balancing the human HSC

  11. A MODEL FOR POSTRADIATION STEM CELL KINETICS,

    Science.gov (United States)

    In polycythemic rats observed for 17 days postradiation (300 R, 250 KVP X-rays) it was noted that stem cell release diminished to 8 percent of the...correlate these findings with a kinetic model of erythropoiesis. It was suggested that the initial depression in stem cell release might be due to cellular

  12. Mesenchymal stem cells in oral reconstructive surgery

    DEFF Research Database (Denmark)

    Jakobsen, C; Sørensen, J A; Kassem, M

    2013-01-01

    This study evaluated clinical outcomes following intraoperative use of adult mesenchymal stem cells (MSCs) in various oral reconstructive procedures. PubMed was searched without language restrictions from 2000 to 2011 using the search words stem cell, oral surgery, tissue engineering, sinus lift...

  13. Skeletal stem cells in space and time

    DEFF Research Database (Denmark)

    Kassem, Moustapha; Bianco, Paolo

    2015-01-01

    The nature, biological characteristics, and contribution to organ physiology of skeletal stem cells are not completely determined. Chan et al. and Worthley et al. demonstrate that a stem cell for skeletal tissues, and a system of more restricted, downstream progenitors, can be identified in mice...

  14. Stem cell treatment of degenerative eye disease.

    Science.gov (United States)

    Mead, Ben; Berry, Martin; Logan, Ann; Scott, Robert A H; Leadbeater, Wendy; Scheven, Ben A

    2015-05-01

    Stem cell therapies are being explored extensively as treatments for degenerative eye disease, either for replacing lost neurons, restoring neural circuits or, based on more recent evidence, as paracrine-mediated therapies in which stem cell-derived trophic factors protect compromised endogenous retinal neurons from death and induce the growth of new connections. Retinal progenitor phenotypes induced from embryonic stem cells/induced pluripotent stem cells (ESCs/iPSCs) and endogenous retinal stem cells may replace lost photoreceptors and retinal pigment epithelial (RPE) cells and restore vision in the diseased eye, whereas treatment of injured retinal ganglion cells (RGCs) has so far been reliant on mesenchymal stem cells (MSC). Here, we review the properties of non-retinal-derived adult stem cells, in particular neural stem cells (NSCs), MSC derived from bone marrow (BMSC), adipose tissues (ADSC) and dental pulp (DPSC), together with ESC/iPSC and discuss and compare their potential advantages as therapies designed to provide trophic support, repair and replacement of retinal neurons, RPE and glia in degenerative retinal diseases. We conclude that ESCs/iPSCs have the potential to replace lost retinal cells, whereas MSC may be a useful source of paracrine factors that protect RGC and stimulate regeneration of their axons in the optic nerve in degenerate eye disease. NSC may have potential as both a source of replacement cells and also as mediators of paracrine treatment. Copyright © 2015. Published by Elsevier B.V.

  15. STEM Studio: Where Innovation Generates Innovation

    Science.gov (United States)

    Plonczak, Irene; Brooks, Jacqueline Grennon; Wilson, Gloria Lodato; Elijah, Rosebud; Caliendo, Julia

    2014-01-01

    STEM Studio at Hofstra University is a clinical practice site that brings together public school pupils and preservice teachers in settings with three features that lead to enhanced learning of all participants: classroom structures using multidisciplinary STEM tasks as platforms for learning; design challenge templates for diverse student…

  16. Pressurizing the STEM Pipeline: an Expectancy-Value Theory Analysis of Youths' STEM Attitudes

    Science.gov (United States)

    Ball, Christopher; Huang, Kuo-Ting; Cotten, Shelia R.; Rikard, R. V.

    2017-08-01

    Over the past decade, there has been a strong national push to increase minority students' positive attitudes towards STEM-related careers. However, despite this focus, minority students have remained underrepresented in these fields. Some researchers have directed their attention towards improving the STEM pipeline which carries students through our educational system and into STEM careers. Previous research has shown that expectancy-value theory (EVT) is useful for examining the short-term as well as long-term academic motivations and intentions of elementary age minority students. These findings provide insights into ways we may be able to potentially "patch" particular STEM pipeline leaks. In the current study, we advance this research by using EVT as a framework to examine the STEM attitudes of young students directly. We hypothesize that students' academic-related expectancies for success and subjective task values will be associated with an increase in STEM attitudes. Data for this study was gathered over the course of a large-scale computing intervention which sought to increase students' STEM interest. This computing intervention took place in an urban elementary school district located within the southeastern USA. Results from this study indicate that both intrinsic values and utility values predict students' STEM attitudes but they influence attitudes related to the various dimensions of STEM differently. These findings demonstrate that EVT provides a useful framework, which can be integrated into future computing interventions, to help encourage positive STEM attitudes in young children, thus increasing the internal pressure (or flow) within the STEM pipeline.

  17. Place Based STEM: Leveraging Local Resources to Engage K-12 Teachers in Teaching Integrated STEM and for Addressing the Local STEM Pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Louis Nadelson; Anne Louise Seifert; Meagan McKinney

    2014-06-01

    Business, industry, parks, nature settings, government infrastructure, and people, can be invaluable resources for connecting STEM curriculum within context which results in conditions ideal for promoting purposeful learning of authentic STEM content. Thus, community-based STEM resources offer ideal context for teaching STEM content. A benefit of focusing teacher attention on these contextual, content aligned resources is that they are in every community; making place-based STEM education a possibility, regardless of the location of STEM teaching and learning. Further, associating STEM teaching and learning with local resources addresses workforce development and the STEM pipeline by exposing students to STEM careers and applications in their local communities. The desire to align STEM teaching and learning with local STEM related resources guided the design of our week-long integrated STEM K-12 teacher professional development (PD) program, i-STEM. We have completed four years of our i-STEM PD program and have made place-based STEM a major emphasis of our curriculum. This report focuses on the data collected in the fourth year of our program. Our week-long i-STEM PD served over 425 educators last summer (2013), providing them with in depth theme-based integrated STEM short courses which were limited to an average of 15 participants and whole group plenary sessions focused around placed based integrated STEM, inquiry, engineering design, standards and practices of Common Core and 21st Century skills. This state wide PD was distributed in five Idaho community colleges and took place over two weeks. The STEM short courses included topics on engineering for sustainability, using engineering to spark interest in STEM, municipal water systems, health, agriculture, food safety, mining, forestry, energy, and others. Integral to these short courses were field trips designed to connect the K-12 educators to the resources in their local communities that could be leveraged

  18. Strategies to improve homing of mesenchymal stem cells for greater efficacy in stem cell therapy.

    Science.gov (United States)

    Naderi-Meshkin, Hojjat; Bahrami, Ahmad Reza; Bidkhori, Hamid Reza; Mirahmadi, Mahdi; Ahmadiankia, Naghmeh

    2015-01-01

    Stem/progenitor cell-based therapeutic approach in clinical practice has been an elusive dream in medical sciences, and improvement of stem cell homing is one of major challenges in cell therapy programs. Stem/progenitor cells have a homing response to injured tissues/organs, mediated by interactions of chemokine receptors expressed on the cells and chemokines secreted by the injured tissue. For improvement of directed homing of the cells, many techniques have been developed either to engineer stem/progenitor cells with higher amount of chemokine receptors (stem cell-based strategies) or to modulate the target tissues to release higher level of the corresponding chemokines (target tissue-based strategies). This review discusses both of these strategies involved in the improvement of stem cell homing focusing on mesenchymal stem cells as most frequent studied model in cellular therapies. © 2014 International Federation for Cell Biology.

  19. The potential application of stem cell in dentistry

    Directory of Open Access Journals (Sweden)

    Ketut Suardita

    2006-12-01

    Full Text Available Stem cells are generally defined as cells that have the capacity to self-renewal and differentiate to specialize cell. There are two kinds of stem cell, embryonic stem cell and adult stem cells. Stem cell therapy has been used to treat diseases including Parkinson’s and Alzheimer’s diseases, spinal cord injury, stroke, burns, heart diseases, diabetes, osteoarthritis, and rheumatoid arthritis. Stem cells were found in dental pulp, periodontal ligament, and alveolar bone marrow. Because of their potential in medical therapy, stem cells were used to regenerate lost or damage teeth and periodontal structures. This article discusses the potential application of stem cells for dental field.

  20. Clinical trials for stem cell transplantation: when are they needed?

    Science.gov (United States)

    Van Pham, Phuc

    2016-04-27

    In recent years, both stem cell research and the clinical application of these promising cells have increased rapidly. About 1000 clinical trials using stem cells have to date been performed globally. More importantly, more than 10 stem cell-based products have been approved in some countries. With the rapid growth of stem cell applications, some countries have used clinical trials as a tool to diminish the rate of clinical stem cell applications. However, the point at which stem cell clinical trials are essential remains unclear. This commentary discusses when stem cell clinical trials are essential for stem cell transplantation therapies.

  1. Persistence of undergraduate women in STEM fields

    Science.gov (United States)

    Pedone, Maggie Helene

    The underrepresentation of women in science, technology, engineering, and mathematics (STEM) is a complex problem that continues to persist at the postsecondary level, particularly in computer science and engineering fields. This dissertation explored the pre-college and college level factors that influenced undergraduate women's persistence in STEM. This study also examined and compared the characteristics of undergraduate women who entered STEM fields and non-STEM fields in 2003-2004. The nationally representative Beginning Postsecondary Students Longitudinal Study (BPS:04/09) data set was used for analysis. BPS:04/09 study respondents were surveyed three times (NPSAS:04, BPS:04/06, BPS:04/09) over a six-year period, which enabled me to explore factors related to long-term persistence. Astin's Input-Environment-Output (I-E-O) model was used as the framework to examine student inputs and college environmental factors that predict female student persistence (output) in STEM. Chi-square tests revealed significant differences between undergraduate women who entered STEM and non-STEM fields in 2003-2004. Differences in student demographics, prior academic achievement, high school course-taking patterns, and student involvement in college such as participation in study groups and school clubs were found. Notably, inferential statistics showed that a significantly higher proportion of female minority students entered STEM fields than non-STEM fields. These findings challenge the myth that underrepresented female minorities are less inclined to enter STEM fields. Logistic regression analyses revealed thirteen significant predictors of persistence for undergraduate women in STEM. Findings showed that undergraduate women who were younger, more academically prepared, and academically and socially involved in college (e.g., lived on campus, interacted with faculty, participated in study groups, fine arts activities, and school sports) were more likely to persist in STEM

  2. Improved cytotoxicity testing of magnesium materials

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Janine [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Department for Structural Research on Macromolecules, Max-Planck Str. 1, D - 21502 Geesthacht (Germany); Proefrock, Daniel [Helmholtz-Zentrum Geesthacht, Institute for Coastal Research, Department for Marine Bioanalytical Chemistry, Max-Planck Str. 1, D - 21502 Geesthacht (Germany); Hort, Norbert [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Department for Magnesium Processing, Max-Planck Str. 1, D - 21502 Geesthacht (Germany); Willumeit, Regine; Feyerabend, Frank [Helmholtz-Zentrum Geesthacht, Institute of Materials Research, Department for Structural Research on Macromolecules, Max-Planck Str. 1, D - 21502 Geesthacht (Germany)

    2011-06-25

    Metallic magnesium (Mg) and its alloys are highly suitable for medical applications as biocompatible and biodegradable implant materials. Magnesium has mechanical properties similar to bone, stimulates bone regeneration, is an essential non-toxic element for the human body and degrades completely within the body environment. In consequence, magnesium is a promising candidate as implant material for orthopaedic applications. Protocols using the guideline of current ISO standards should be carefully evaluated when applying them for the characterization of the cytotoxic potential of degradable magnesium materials. For as-cast material we recommend using 10 times more extraction medium than recommended by the ISO standards to obtain reasonable results for reliable cytotoxicity rankings of degradable materials in vitro. In addition primary isolated human osteoblasts or mesenchymal stem cells should be used to test magnesium materials.

  3. Improved cytotoxicity testing of magnesium materials

    International Nuclear Information System (INIS)

    Fischer, Janine; Proefrock, Daniel; Hort, Norbert; Willumeit, Regine; Feyerabend, Frank

    2011-01-01

    Metallic magnesium (Mg) and its alloys are highly suitable for medical applications as biocompatible and biodegradable implant materials. Magnesium has mechanical properties similar to bone, stimulates bone regeneration, is an essential non-toxic element for the human body and degrades completely within the body environment. In consequence, magnesium is a promising candidate as implant material for orthopaedic applications. Protocols using the guideline of current ISO standards should be carefully evaluated when applying them for the characterization of the cytotoxic potential of degradable magnesium materials. For as-cast material we recommend using 10 times more extraction medium than recommended by the ISO standards to obtain reasonable results for reliable cytotoxicity rankings of degradable materials in vitro. In addition primary isolated human osteoblasts or mesenchymal stem cells should be used to test magnesium materials.

  4. Nonclinical safety strategies for stem cell therapies

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, Michaela E., E-mail: michaela_sharpe@yahoo.com [Investigative Toxicology, Drug Safety Research and Development, Pfizer Ltd, Ramsgate Road, Sandwich, CT13 9NJ (United Kingdom); Morton, Daniel [Exploratory Drug Safety, Drug Safety Research and Development, Pfizer Inc, Cambridge, 02140 (United States); Rossi, Annamaria [Investigative Toxicology, Drug Safety Research and Development, Pfizer Ltd, Ramsgate Road, Sandwich, CT13 9NJ (United Kingdom)

    2012-08-01

    Recent breakthroughs in stem cell biology, especially the development of the induced pluripotent stem cell techniques, have generated tremendous enthusiasm and efforts to explore the therapeutic potential of stem cells in regenerative medicine. Stem cell therapies are being considered for the treatment of degenerative diseases, inflammatory conditions, cancer and repair of damaged tissue. The safety of a stem cell therapy depends on many factors including the type of cell therapy, the differentiation status and proliferation capacity of the cells, the route of administration, the intended clinical location, long term survival of the product and/or engraftment, the need for repeated administration, the disease to be treated and the age of the population. Understanding the product profile of the intended therapy is crucial to the development of the nonclinical safety study design.

  5. Nanotopographical Control of Stem Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Laura E. McNamara

    2010-01-01

    Full Text Available Stem cells have the capacity to differentiate into various lineages, and the ability to reliably direct stem cell fate determination would have tremendous potential for basic research and clinical therapy. Nanotopography provides a useful tool for guiding differentiation, as the features are more durable than surface chemistry and can be modified in size and shape to suit the desired application. In this paper, nanotopography is examined as a means to guide differentiation, and its application is described in the context of different subsets of stem cells, with a particular focus on skeletal (mesenchymal stem cells. To address the mechanistic basis underlying the topographical effects on stem cells, the likely contributions of indirect (biochemical signal-mediated and direct (force-mediated mechanotransduction are discussed. Data from proteomic research is also outlined in relation to topography-mediated fate determination, as this approach provides insight into the global molecular changes at the level of the functional effectors.

  6. Overcoming Multidrug Resistance in Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Karobi Moitra

    2015-01-01

    Full Text Available The principle mechanism of protection of stem cells is through the expression of ATP-binding cassette (ABC transporters. These transporters serve as the guardians of the stem cell population in the body. Unfortunately these very same ABC efflux pumps afford protection to cancer stem cells in tumors, shielding them from the adverse effects of chemotherapy. A number of strategies to circumvent the function of these transporters in cancer stem cells are currently under investigation. These strategies include the development of competitive and allosteric modulators, nanoparticle mediated delivery of inhibitors, targeted transcriptional regulation of ABC transporters, miRNA mediated inhibition, and targeting of signaling pathways that modulate ABC transporters. The role of ABC transporters in cancer stem cells will be explored in this paper and strategies aimed at overcoming drug resistance caused by these particular transporters will also be discussed.

  7. Cancer stem cells of the digestive system.

    Science.gov (United States)

    Colvin, Hugh S; Nishida, Naohiro; Koseki, Jun; Konno, Masamitsu; Kawamoto, Koichi; Tsunekuni, Kenta; Doki, Yuichiro; Mori, Masaki; Ishii, Hideshi

    2014-12-01

    Stem cells of the digestive system are ideal in many ways for research, given they are abundant, highly proliferative and have a uniform structural arrangement. This in turn has enormously aided the research of cancer stem cells of the digestive system, which is now shaping our understanding of cancer stem cells. In this review, the recent advances in the understanding of cancer stem cells of the digestive system have been summarized, including aspects such as their identification, origin, cell-cycle dormancy, relationship with epithelial-mesenchymal transition, cellular metabolism and the underlying molecular mechanisms. Newly acquired knowledge concerning cancer stem cells have led to the development of novel cancer therapeutics with provisional yet encouraging results. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Skin Stem Cells in Skin Cell Therapy

    Directory of Open Access Journals (Sweden)

    Mollapour Sisakht

    2015-12-01

    Full Text Available Context Preclinical and clinical research has shown that stem cell therapy is a promising therapeutic option for many diseases. This article describes skin stem cells sources and their therapeutic applications. Evidence Acquisition Compared with conventional methods, cell therapy reduces the surgical burden for patients because it is simple and less time-consuming. Skin cell therapy has been developed for variety of diseases. By isolation of the skin stem cell from the niche, in vitro expansion and transplantation of cells offers a surprising healing capacity profile. Results Stem cells located in skin cells have shown interesting properties such as plasticity, transdifferentiation, and specificity. Mesenchymal cells of the dermis, hypodermis, and other sources are currently being investigated to promote regeneration. Conclusions Because skin stem cells are highly accessible from autologous sources and their immunological profile is unique, they are ideal for therapeutic approaches. Optimization of administrative routes requires more investigation own to the lack of a standard protocol.

  9. Nonclinical safety strategies for stem cell therapies

    International Nuclear Information System (INIS)

    Sharpe, Michaela E.; Morton, Daniel; Rossi, Annamaria

    2012-01-01

    Recent breakthroughs in stem cell biology, especially the development of the induced pluripotent stem cell techniques, have generated tremendous enthusiasm and efforts to explore the therapeutic potential of stem cells in regenerative medicine. Stem cell therapies are being considered for the treatment of degenerative diseases, inflammatory conditions, cancer and repair of damaged tissue. The safety of a stem cell therapy depends on many factors including the type of cell therapy, the differentiation status and proliferation capacity of the cells, the route of administration, the intended clinical location, long term survival of the product and/or engraftment, the need for repeated administration, the disease to be treated and the age of the population. Understanding the product profile of the intended therapy is crucial to the development of the nonclinical safety study design.

  10. Biophysical regulation of stem cell differentiation.

    Science.gov (United States)

    Govey, Peter M; Loiselle, Alayna E; Donahue, Henry J

    2013-06-01

    Bone adaptation to its mechanical environment, from embryonic through adult life, is thought to be the product of increased osteoblastic differentiation from mesenchymal stem cells. In parallel with tissue-scale loading, these heterogeneous populations of multipotent stem cells are subject to a variety of biophysical cues within their native microenvironments. Bone marrow-derived mesenchymal stem cells-the most broadly studied source of osteoblastic progenitors-undergo osteoblastic differentiation in vitro in response to biophysical signals, including hydrostatic pressure, fluid flow and accompanying shear stress, substrate strain and stiffness, substrate topography, and electromagnetic fields. Furthermore, stem cells may be subject to indirect regulation by mechano-sensing osteocytes positioned to more readily detect these same loading-induced signals within the bone matrix. Such paracrine and juxtacrine regulation of differentiation by osteocytes occurs in vitro. Further studies are needed to confirm both direct and indirect mechanisms of biophysical regulation within the in vivo stem cell niche.

  11. Cytokine signalling in embryonic stem cells

    DEFF Research Database (Denmark)

    Kristensen, David Møbjerg; Kalisz, Mark; Nielsen, Jens Høiriis

    2006-01-01

    Cytokines play a central role in maintaining self-renewal in mouse embryonic stem (ES) cells through a member of the interleukin-6 type cytokine family termed leukemia inhibitory factor (LIF). LIF activates the JAK-STAT3 pathway through the class I cytokine receptor gp130, which forms a trimeric...... pathways seem to converge on c-myc as a common target to promote self-renewal. Whereas LIF does not seem to stimulate self-renewal in human embryonic stem cells it cannot be excluded that other cytokines are involved. The pleiotropic actions of the increasing number of cytokines and receptors signalling...... via JAKs, STATs and SOCS exhibit considerable redundancy, compensation and plasticity in stem cells in accordance with the view that stem cells are governed by quantitative variations in strength and duration of signalling events known from other cell types rather than qualitatively different stem...

  12. Eckol suppresses maintenance of stemness and malignancies in glioma stem-like cells

    International Nuclear Information System (INIS)

    Hyun, Kyung-Hwan; Yoon, Chang-Hwan; Kim, Rae-Kwon; Lim, Eun-Jung; An, Sungkwan; Park, Myung-Jin; Hyun, Jin-Won; Suh, Yongjoon; Kim, Min-Jung; Lee, Su-Jae

    2011-01-01

    A subpopulation of cancer cells with stem cell properties is responsible for tumor maintenance and progression, and may contribute to resistance to anticancer treatments. Thus, compounds that target cancer stem-like cells could be usefully applied to destroy cancer. In this study, we investigated the effect of Eckol, a phlorotannin compound, on stemness and malignancies in glioma stem-like cells. To determine whether Eckol targets glioma stem-like cells, we examined whether Eckol treatment could change the expression levels of glioma stem-like cell markers and self-renewal-related proteins as well as the sphere forming ability, and the sensitivity to anticancer treatments. Alterations in the malignant properties of sphere-derived cells by Eckol were also investigated by soft-agar colony forming assay, by xenograft assay in nude mice, and by cell invasion assay. Treatment of sphere-forming glioma cells with Eckol effectively decreased the sphere formation as well as the CD133 + cell population. Eckol treatment suppressed expression of the glioma stem-like cell markers and the self-renewal-related proteins without cell death. Moreover, treatment of glioma stem-like cells with Eckol significantly attenuated anchorage-independent growth on soft agar and tumor formation in xenograft mice. Importantly, Eckol treatment effectively reduced the resistance of glioma stem-like cells to ionizing radiation and temozolomide. Treatment of glioma stem-like cells with Eckol markedly blocked both phosphoinositide 3-kinase-Akt and Ras-Raf-1-Erk signaling pathways. These results indicate that the natural phlorotannin Eckol suppresses stemness and malignancies in glioma stem-like cells, and thereby makes glioma stem-like cells more sensitive to anticancer treatments, providing novel therapeutic strategies targeting specifically cancer stem-like cells.

  13. Stem cell factor supports migration in canine mesenchymal stem cells.

    Science.gov (United States)

    Enciso, Nathaly; Ostronoff, Luciana L K; Mejías, Guillermo; León, Leticia G; Fermín, María Luisa; Merino, Elena; Fragio, Cristina; Avedillo, Luis; Tejero, Concepción

    2018-03-01

    Adult Mesenchymal Stem Cells (MSC) are cells that can be defined as multipotent cells able to differentiate into diverse lineages, under appropriate conditions. These cells have been widely used in regenerative medicine, both in preclinical and clinical settings. Initially discovered in bone marrow, MSC can now be isolated from a wide spectrum of adult and foetal tissues. Studies to evaluate the therapeutic potential of these cells are based on their ability to arrive to damaged tissues. In this paper we have done a comparative study analyzing proliferation, surface markers and OCT4, SOX9, RUNX2, PPARG genes expression in MSC cells from Bone marrow (BMMSC) and Adipose tissue (ASC). We also analyzed the role of Stem Cell Factor (SCF) on MSC proliferation and on ASCs metalloproteinases MMP-2, MMP-9 secretion. Healthy dogs were used as BMMSC donors, and ASC were collected from omentum during elective ovariohysterectomy surgery. Both cell types were cultured in IMDM medium with or without SCF, 10% Dog Serum (DS), and incubated at 38 °C with 5% CO2. Growth of BMMSCs and ASCs was exponential until 25-30 days. Flow citometry of MSCs revealed positive results for CD90 and negative for CD34, CD45 and MCH-II. Genes were evaluated by RT-PCR and metalloproteinases by zymografy. Our findings indicate morphological and immunological similarities as well as expression of genes from both origins on analyzed cells. Furthermore, SCF did not affect proliferation of MSCs, however it up-regulated MMP-2 and MMP-9 secretion in ASCs. These results suggest that metalloproteinases are possibly essential molecules pivoting migration.

  14. Curbing stem cell tourism in South Africa.

    Science.gov (United States)

    Meissner-Roloff, Madelein; Pepper, Michael S

    2013-12-01

    Stem cells have received much attention globally due in part to the immense therapeutic potential they harbor. Unfortunately, malpractice and exploitation (financial and emotional) of vulnerable patients have also drawn attention to this field as a result of the detrimental consequences experienced by some individuals that have undergone unproven stem cell therapies. South Africa has had limited exposure to stem cells and their applications and, while any exploitation is detrimental to the field of stem cells, South Africa is particularly vulnerable in this regard. The current absence of adequate legislation and the inability to enforce existing legislation, coupled to the sea of misinformation available on the Internet could lead to an increase in illegitimate stem cell practices in South Africa. Circumstances are already precarious because of a lack of understanding of concepts involved in stem cell applications. What is more, credible and easily accessible information is not available to the public. This in turn cultivates fears born out of existing superstitions, cultural beliefs, rituals and practices. Certain cultural or religious concerns could potentially hinder the effective application of stem cell therapies in South Africa and novel ways of addressing these concerns are necessary. Understanding how scientific progress and its implementation will affect each individual and, consequently, the community, will be of cardinal importance to the success of the fields of stem cell therapy and regenerative medicine in South Africa. A failure to understand the ethical, cultural or moral ramifications when new scientific concepts are introduced could hinder the efficacy and speed of bringing discoveries to the patient. Neglecting proper procedure for establishing the field would lead to long delays in gaining public support in South Africa. Understanding the dangers of stem cell tourism - where vulnerable patients are subjected to unproven stem cell therapies that

  15. Layered materials

    Science.gov (United States)

    Johnson, David; Clarke, Simon; Wiley, John; Koumoto, Kunihito

    2014-06-01

    Layered compounds, materials with a large anisotropy to their bonding, electrical and/or magnetic properties, have been important in the development of solid state chemistry, physics and engineering applications. Layered materials were the initial test bed where chemists developed intercalation chemistry that evolved into the field of topochemical reactions where researchers are able to perform sequential steps to arrive at kinetically stable products that cannot be directly prepared by other approaches. Physicists have used layered compounds to discover and understand novel phenomena made more apparent through reduced dimensionality. The discovery of charge and spin density waves and more recently the remarkable discovery in condensed matter physics of the two-dimensional topological insulating state were discovered in two-dimensional materials. The understanding developed in two-dimensional materials enabled subsequent extension of these and other phenomena into three-dimensional materials. Layered compounds have also been used in many technologies as engineers and scientists used their unique properties to solve challenging technical problems (low temperature ion conduction for batteries, easy shear planes for lubrication in vacuum, edge decorated catalyst sites for catalytic removal of sulfur from oil, etc). The articles that are published in this issue provide an excellent overview of the spectrum of activities that are being pursued, as well as an introduction to some of the most established achievements in the field. Clusters of papers discussing thermoelectric properties, electronic structure and transport properties, growth of single two-dimensional layers, intercalation and more extensive topochemical reactions and the interleaving of two structures to form new materials highlight the breadth of current research in this area. These papers will hopefully serve as a useful guideline for the interested reader to different important aspects in this field and

  16. Electronic materials

    CERN Document Server

    Kwok, H L

    2010-01-01

    The electronic properties of solids have become of increasing importance in the age of information technology. The study of solids and materials, while having originated from the disciplines of physics and chemistry, has evolved independently over the past few decades. The classical treatment of solid-state physics, which emphasized classifications, theories and fundamental physical principles, is no longer able to bridge the gap between materials advances and applications. In particular, the more recent developments in device physics and technology have not necessarily been driven by new conc

  17. Glucocorticoids and hemopoietic stem cells

    International Nuclear Information System (INIS)

    Romashko, O.O.; Berin, G.I.

    1978-01-01

    Analyzing the data of home and foreign investigators the problems of the glucocorticoid effect on blood and bone marrow of experimental (including irradiated ones) animals are discussed. Considered are a character and mechanism of the adrenal cortex hormones effect on blood formation, as well as the effect of pharmacological doses of corticosteroids on CFU, their erythropoietic effect in physiological doses on a morphological picture of bone marrow after irradiation and subsequent introduction of hormones and the hormone effect on intensity of erythropoiesis recovery in irradiated mice. Presented are the experimental data on studying the effect of endogenic hypercorticoidism and a reduced level of endogenic corticosteroids on blood-forming stem cells in the irradiated mice and the data on the ACTH injection effect on CFU migration after irradiation. Evaluated are already available data and further investigations to ground advisability and conditions of using corticosteroids as well as determining rational therapeutic effects on secretion of endogenic glucocorticoids when treating blood system diseases

  18. [Embryonic stem cells. Future perspectives].

    Science.gov (United States)

    Groebner, M; David, R; Franz, W M

    2006-05-01

    Embryonic stem cells (ES cells) are able to differentiate into any cell type, and therefore represent an excellent source for cellular replacement therapies in the case of widespread diseases, for example heart failure, diabetes, Parkinson's disease and spinal cord injury. A major prerequisite for their efficient and safe clinical application is the availability of pure populations for direct cell transplantation or tissue engineering as well as the immunological compatibility of the transplanted cells. The expression of human surface markers under the control of cell type specific promoters represents a promising approach for the selection of cardiomyocytes and other cell types for therapeutic applications. The first human clinical trial using ES cells will start in the United States this year.

  19. Ethnic variation in gender-STEM stereotypes and STEM participation: an intersectional approach.

    Science.gov (United States)

    O'Brien, Laurie T; Blodorn, Alison; Adams, Glenn; Garcia, Donna M; Hammer, Elliott

    2015-04-01

    Stereotypes associating men and masculine traits with science, technology, engineering, and mathematics (STEM) fields are ubiquitous, but the relative strength of these stereotypes varies considerably across cultures. The present research applies an intersectional approach to understanding ethnic variation in gender-STEM stereotypes and STEM participation within an American university context. African American college women participated in STEM majors at higher rates than European American college women (Study 1, Study 2, and Study 4). Furthermore, African American women had weaker implicit gender-STEM stereotypes than European American women (Studies 2-4), and ethnic differences in implicit gender-STEM stereotypes partially mediated ethnic differences in STEM participation (Study 2 and Study 4). Although African American men had weaker implicit gender-STEM stereotypes than European American men (Study 4), ethnic differences between men in STEM participation were generally small (Study 1) or nonsignificant (Study 4). We discuss the implications of an intersectional approach for understanding the relationship between gender and STEM participation. (c) 2015 APA, all rights reserved).

  20. A Continuum Diffusion Model for Viscoelastic Materials

    Science.gov (United States)

    1988-11-01

    ZIP Code) 7b. ADDRESS (CJI. Slow, and ZIP Code) Mechanics Div isi on Office of Naval Research; Code 432 Collge Satio, T as 7843800 Quincy Ave. Collge ...these studies, which involved experimental, analytical, and materials science aspects, were conducted by researchers in the fields of physical and...thermodynamics, with irreversibility stemming from the foregoing variables yr through "growth laws" that correspond to viscous resistance. The physical ageing of

  1. Harvesting, processing and inventory management of peripheral blood stem cells

    Directory of Open Access Journals (Sweden)

    Mijovic Aleksandar

    2007-01-01

    correlate with the apheresis yields. These are, in turn, predictive of the speed of haemopoietic recovery after transplantation, which has helped establish the adequate cell dose for transplantation. Following collection, PBSC may be transfused unmanipulated, processed to select specific cell subtypes, or stored for future use. Cryopreservation techniques allow long term storage of stem cells without significant loss of viability. Increasingly demanding calls for safety led to introduction of vapour phase storage, separate storage of infected material, and mandatory quality control measures at all stages of the cryopreservation process and subsequent thawing and transfusion. At the same time, safety of the personnel working in stem cell processing and storage laboratories is safeguarded by a set of regulations devised to minimize the risk of infection, injury or hypoxia. Requirements for quality and safety have been shaped into a number of documents and directives in Europe and USA, emphasising the importance of product traceability, reporting of adverse reactions, quality management systems (standard operating procedures, guidelines, training records, reporting mechanisms and records, requirements for cell reception, quarantine, process control, validation and storage. Establishments that collect, process and store stem cells must be accredited or licensed by appropriate national or international authorities on a regular basis. These regulatory measures have recently become law across the European Union.

  2. Mesenchymal stem cell adhesion but not plasticity is affected by high substrate stiffness

    Directory of Open Access Journals (Sweden)

    Janice Kal Van Tam, Koichiro Uto, Mitsuhiro Ebara, Stefania Pagliari, Giancarlo Forte and Takao Aoyagi

    2012-01-01

    Full Text Available The acknowledged ability of synthetic materials to induce cell-specific responses regardless of biological supplies provides tissue engineers with the opportunity to find the appropriate materials and conditions to prepare tissue-targeted scaffolds. Stem and mature cells have been shown to acquire distinct morphologies in vitro and to modify their phenotype when grown on synthetic materials with tunable mechanical properties. The stiffness of the substrate used for cell culture is likely to provide cells with mechanical cues mimicking given physiological or pathological conditions, thus affecting the biological properties of cells. The sensitivity of cells to substrate composition and mechanical properties resides in multiprotein complexes called focal adhesions, whose dynamic modification leads to cytoskeleton remodeling and changes in gene expression. In this study, the remodeling of focal adhesions in human mesenchymal stem cells in response to substrate stiffness was followed in the first phases of cell–matrix interaction, using poly-ε-caprolactone planar films with similar chemical composition and different elasticity. As compared to mature dermal fibroblasts, mesenchymal stem cells showed a specific response to substrate stiffness, in terms of adhesion, as a result of differential focal adhesion assembly, while their multipotency as a bulk was not significantly affected by matrix compliance. Given the sensitivity of stem cells to matrix mechanics, the mechanobiology of such cells requires further investigations before preparing tissue-specific scaffolds.

  3. The Stem Cell Hypothesis of Aging

    Directory of Open Access Journals (Sweden)

    Anna Meiliana

    2010-04-01

    Full Text Available BACKGROUND: There is probably no single way to age. Indeed, so far there is no single accepted explanation or mechanisms of aging (although more than 300 theories have been proposed. There is an overall decline in tissue regenerative potential with age, and the question arises as to whether this is due to the intrinsic aging of stem cells or rather to the impairment of stem cell function in the aged tissue environment. CONTENT: Recent data suggest that we age, in part, because our self-renewing stem cells grow old as a result of heritable intrinsic events, such as DNA damage, as well as extrinsic forces, such as changes in their supporting niches. Mechanisms that suppress the development of cancer, such as senescence and apoptosis, which rely on telomere shortening and the activities of p53 and p16INK4a may also induce an unwanted consequence: a decline in the replicative function of certain stem cells types with advancing age. This decrease regenerative capacity appears to pointing to the stem cell hypothesis of aging. SUMMARY: Recent evidence suggested that we grow old partly because of our stem cells grow old as a result of mechanisms that suppress the development of cancer over a lifetime. We believe that a further, more precise mechanistic understanding of this process will be required before this knowledge can be translated into human anti-aging therapies. KEYWORDS: stem cells, senescence, telomere, DNA damage, epigenetic, aging.

  4. Technology advancement for integrative stem cell analyses.

    Science.gov (United States)

    Jeong, Yoon; Choi, Jonghoon; Lee, Kwan Hyi

    2014-12-01

    Scientists have endeavored to use stem cells for a variety of applications ranging from basic science research to translational medicine. Population-based characterization of such stem cells, while providing an important foundation to further development, often disregard the heterogeneity inherent among individual constituents within a given population. The population-based analysis and characterization of stem cells and the problems associated with such a blanket approach only underscore the need for the development of new analytical technology. In this article, we review current stem cell analytical technologies, along with the advantages and disadvantages of each, followed by applications of these technologies in the field of stem cells. Furthermore, while recent advances in micro/nano technology have led to a growth in the stem cell analytical field, underlying architectural concepts allow only for a vertical analytical approach, in which different desirable parameters are obtained from multiple individual experiments and there are many technical challenges that limit vertically integrated analytical tools. Therefore, we propose--by introducing a concept of vertical and horizontal approach--that there is the need of adequate methods to the integration of information, such that multiple descriptive parameters from a stem cell can be obtained from a single experiment.

  5. Time to Reconsider Stem Cell Induction Strategies

    Directory of Open Access Journals (Sweden)

    Hans-Werner Denker

    2012-12-01

    Full Text Available Recent developments in stem cell research suggest that it may be time to reconsider the current focus of stem cell induction strategies. During the previous five years, approximately, the induction of pluripotency in somatic cells, i.e., the generation of so-called ‘induced pluripotent stem cells’ (iPSCs, has become the focus of ongoing research in many stem cell laboratories, because this technology promises to overcome limitations (both technical and ethical seen in the production and use of embryonic stem cells (ESCs. A rapidly increasing number of publications suggest, however, that it is now possible to choose instead other, alternative ways of generating stem and progenitor cells bypassing pluripotency. These new strategies may offer important advantages with respect to ethics, as well as to safety considerations. The present communication discusses why these strategies may provide possibilities for an escape from the dilemma presented by pluripotent stem cells (self-organization potential, cloning by tetraploid complementation, patenting problems and tumor formation risk.

  6. Fundamental Principles of Stem Cell Banking.

    Science.gov (United States)

    Sun, Changbin; Yue, Jianhui; He, Na; Liu, Yaqiong; Zhang, Xi; Zhang, Yong

    2016-01-01

    Stem cells are highly promising resources for application in cell therapy, regenerative medicine, drug discovery, toxicology and developmental biology research. Stem cell banks have been increasingly established all over the world in order to preserve their cellular characteristics, prevent contamination and deterioration, and facilitate their effective use in basic and translational research, as well as current and future clinical application. Standardization and quality control during banking procedures are essential to allow researchers from different labs to compare their results and to develop safe and effective new therapies. Furthermore, many stem cells come from once-in-a-life time tissues. Cord blood for example, thrown away in the past, can be used to treat many diseases such as blood cancers nowadays. Meanwhile, these cells stored and often banked for long periods can be immediately available for treatment when needed and early treatment can minimize disease progression. This paper provides an overview of the fundamental principles of stem cell banking, including: (i) a general introduction of the construction and architecture commonly used for stem cell banks; (ii) a detailed section on current quality management practices; (iii) a summary of questions we should consider for long-term storage, such as how long stem cells can be stored stably, how to prevent contamination during long term storage, etc.; (iv) the prospects for stem cell banking.

  7. Adult Stem Cells and Diseases of Aging

    Directory of Open Access Journals (Sweden)

    Lisa B. Boyette

    2014-01-01

    Full Text Available Preservation of adult stem cells pools is critical for maintaining tissue homeostasis into old age. Exhaustion of adult stem cell pools as a result of deranged metabolic signaling, premature senescence as a response to oncogenic insults to the somatic genome, and other causes contribute to tissue degeneration with age. Both progeria, an extreme example of early-onset aging, and heritable longevity have provided avenues to study regulation of the aging program and its impact on adult stem cell compartments. In this review, we discuss recent findings concerning the effects of aging on stem cells, contributions of stem cells to age-related pathologies, examples of signaling pathways at work in these processes, and lessons about cellular aging gleaned from the development and refinement of cellular reprogramming technologies. We highlight emerging therapeutic approaches to manipulation of key signaling pathways corrupting or exhausting adult stem cells, as well as other approaches targeted at maintaining robust stem cell pools to extend not only lifespan but healthspan.

  8. Stem Cell Lineages: Between Cell and Organism

    Directory of Open Access Journals (Sweden)

    Melinda Bonnie Fagan

    2017-01-01

    Full Text Available Ontologies of living things are increasingly grounded on the concepts and practices of current life science. Biological development is a process, undergone by living things, which begins with a single cell and (in an important class of cases ends with formation of a multicellular organism. The process of development is thus prima facie central for ideas about biological individuality and organismality. However, recent accounts of these concepts do not engage developmental biology. This paper aims to fill the gap, proposing the lineage view of stem cells as an ontological framework for conceptualizing organismal development. This account is grounded on experimental practices of stem cell research, with emphasis on new techniques for generating biological organization in vitro. On the lineage view, a stem cell is the starting point of a cell lineage with a specific organismal source, time-interval of existence, and ‘tree topology’ of branch-points linking the stem to developmental termini. The concept of ‘enkapsis’ accommodates the cell-organism relation within the lineage view; this hierarchical notion is further explicated by considering the methods and results of stem cell experiments. Results of this examination include a (partial characterization of stem cells’ developmental versatility, and the context-dependence of developmental processes involving stem cells.

  9. Stem cell bioprocessing: fundamentals and principles.

    Science.gov (United States)

    Placzek, Mark R; Chung, I-Ming; Macedo, Hugo M; Ismail, Siti; Mortera Blanco, Teresa; Lim, Mayasari; Cha, Jae Min; Fauzi, Iliana; Kang, Yunyi; Yeo, David C L; Ma, Chi Yip Joan; Polak, Julia M; Panoskaltsis, Nicki; Mantalaris, Athanasios

    2009-03-06

    In recent years, the potential of stem cell research for tissue engineering-based therapies and regenerative medicine clinical applications has become well established. In 2006, Chung pioneered the first entire organ transplant using adult stem cells and a scaffold for clinical evaluation. With this a new milestone was achieved, with seven patients with myelomeningocele receiving stem cell-derived bladder transplants resulting in substantial improvements in their quality of life. While a bladder is a relatively simple organ, the breakthrough highlights the incredible benefits that can be gained from the cross-disciplinary nature of tissue engineering and regenerative medicine (TERM) that encompasses stem cell research and stem cell bioprocessing. Unquestionably, the development of bioprocess technologies for the transfer of the current laboratory-based practice of stem cell tissue culture to the clinic as therapeutics necessitates the application of engineering principles and practices to achieve control, reproducibility, automation, validation and safety of the process and the product. The successful translation will require contributions from fundamental research (from developmental biology to the 'omics' technologies and advances in immunology) and from existing industrial practice (biologics), especially on automation, quality assurance and regulation. The timely development, integration and execution of various components will be critical-failures of the past (such as in the commercialization of skin equivalents) on marketing, pricing, production and advertising should not be repeated. This review aims to address the principles required for successful stem cell bioprocessing so that they can be applied deftly to clinical applications.

  10. Stem cell applications in military medicine.

    Science.gov (United States)

    Christopherson, Gregory T; Nesti, Leon J

    2011-10-19

    There are many similarities between health issues affecting military and civilian patient populations, with the exception of the relatively small but vital segment of active soldiers who experience high-energy blast injuries during combat. A rising incidence of major injuries from explosive devices in recent campaigns has further complicated treatment and recovery, highlighting the need for tissue regenerative options and intensifying interest in the possible role of stem cells for military medicine. In this review we outline the array of tissue-specific injuries typically seen in modern combat - as well as address a few complications unique to soldiers--and discuss the state of current stem cell research in addressing each area. Embryonic, induced-pluripotent and adult stem cell sources are defined, along with advantages and disadvantages unique to each cell type. More detailed stem cell sources are described in the context of each tissue of interest, including neural, cardiopulmonary, musculoskeletal and sensory tissues, with brief discussion of their potential role in regenerative medicine moving forward. Additional commentary is given to military stem cell applications aside from regenerative medicine, such as blood pharming, immunomodulation and drug screening, with an overview of stem cell banking and the unique opportunity provided by the military and civilian overlap of stem cell research.

  11. Adolescent Girls’ STEM Identity Formation and Media Images of STEM Professionals: Considering the Influence of Contextual Cues

    Science.gov (United States)

    Steinke, Jocelyn

    2017-01-01

    Popular media have played a crucial role in the construction, representation, reproduction, and transmission of stereotypes of science, technology, engineering, and mathematics (STEM) professionals, yet little is known about how these stereotypes influence STEM identity formation. Media images of STEM professionals may be important sources of information about STEM and may be particularly salient and relevant for girls during adolescence as they actively consider future personal and professional identities. This article describes gender-stereotyped media images of STEM professionals and examines theories to identify variables that explain the potential influence of these images on STEM identity formation. Understanding these variables is important for expanding current conceptual frameworks of science/STEM identity to better determine how and when cues in the broader sociocultural context may affect adolescent girls’ STEM identity. This article emphasizes the importance of focusing on STEM identity relevant variables and STEM identity status to explain individual differences in STEM identity formation. PMID:28603505

  12. Adolescent Girls' STEM Identity Formation and Media Images of STEM Professionals: Considering the Influence of Contextual Cues.

    Science.gov (United States)

    Steinke, Jocelyn

    2017-01-01

    Popular media have played a crucial role in the construction, representation, reproduction, and transmission of stereotypes of science, technology, engineering, and mathematics (STEM) professionals, yet little is known about how these stereotypes influence STEM identity formation. Media images of STEM professionals may be important sources of information about STEM and may be particularly salient and relevant for girls during adolescence as they actively consider future personal and professional identities. This article describes gender-stereotyped media images of STEM professionals and examines theories to identify variables that explain the potential influence of these images on STEM identity formation. Understanding these variables is important for expanding current conceptual frameworks of science/STEM identity to better determine how and when cues in the broader sociocultural context may affect adolescent girls' STEM identity. This article emphasizes the importance of focusing on STEM identity relevant variables and STEM identity status to explain individual differences in STEM identity formation.

  13. Supplementary Material

    Indian Academy of Sciences (India)

    mraga

    1. Supplementary Material. A soluble-lead Redox Flow Battery with corrugated graphite sheet and reticulated vitreous carbon as positive and negative current collectors by A Banerjee et al (pp 163-. 170). Figure S1. SEM images for bare substrates: (a) graphite sheet, (b) 20 ppi RVC, (c) 30 ppi. RVC and (d) 45 ppi RVC.

  14. Emerging Materiality

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege; Breinbjerg, Morten; Pold, Søren

    2009-01-01

    The authors examine how materiality emerges from complex chains of mediation in creative software use. The primarily theoretical argument is inspired and illustrated by interviews with two composers of electronic music. The authors argue that computer mediated activity should not primarily be und...

  15. Atmospheric materiality

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2016-01-01

    experience and, consequently, to the conceptual and methodological shifts in the production of space, and hence in the way we think about materiality. In this context, architectural space is understood as a contingent construction – a space of engagement that appears to us as a result of continuous...

  16. Absorbant materials

    International Nuclear Information System (INIS)

    Quetier, Monique.

    1978-11-01

    Absorbants play a very important part in the nuclear industry. They serve for the control, shut-down and neutron shielding of reactors and increase the capacity of spent fuel storage pools and of special transport containers. This paper surveys the usual absorbant materials, means of obtainment, their essential characteristics relating to their use and their behaviour under neutron irradiation [fr

  17. Does oolong tea (Camellia sinensis) made from a combination of leaf and stem smell more aromatic than leaf-only tea? Contribution of the stem to oolong tea aroma.

    Science.gov (United States)

    Zeng, Lanting; Zhou, Ying; Fu, Xiumin; Mei, Xin; Cheng, Sihua; Gui, Jiadong; Dong, Fang; Tang, Jinchi; Ma, Shengzhou; Yang, Ziyin

    2017-12-15

    The raw materials used to make oolong tea (Camellia sinensis) are a combination of leaf and stem. Oolong tea made from leaf and stem is thought to have a more aromatic smell than leaf-only tea. However, there is no available evidence to support the viewpoint. In this study, sensory evaluation and detailed characterization of emitted and internal volatiles (not readily emitted, but stored in samples) of dry oolong teas and infusions indicated that the presence of stem did not significantly improve the total aroma characteristics. During the enzyme-active processes, volatile monoterpenes and theanine were accumulated more abundantly in stem than in leaf, while jasmine lactone, indole, and trans-nerolidol were lower in stem than in leaf. Tissue-specific aroma-related gene expression and availability of precursors of aroma compounds resulted in different aroma distributions in leaf and stem. This study presents the first determination of the contribution of stem to oolong tea aroma. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Adhesion of mesenchymal stem cells to biomimetic polymers: A review

    Energy Technology Data Exchange (ETDEWEB)

    Shotorbani, Behnaz Banimohamad [Research Institute for Fundamental Sciences (RIFS), University of Tabriz, Tabriz (Iran, Islamic Republic of); Alizadeh, Effat, E-mail: Alizadehe@tbzmed.ac.ir [Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Drug Applied Research Center and Faculty of advanced Medical Science, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); The Umbilical Cord Stem Cell Research Center (UCSRC), Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Salehi, Roya [Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Drug Applied Research Center and Faculty of advanced Medical Science, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); The Umbilical Cord Stem Cell Research Center (UCSRC), Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Barzegar, Abolfazl [Research Institute for Fundamental Sciences (RIFS), University of Tabriz, Tabriz (Iran, Islamic Republic of); Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of)

    2017-02-01

    The mesenchymal stem cells (MSCs) are promising candidates for cell therapy due to the self-renewal, multi-potency, ethically approved state and suitability for autologous transplantation. However, key issue for isolation and manipulation of MSCs is adhesion in ex-vivo culture systems. Biomaterials engineered for mimicking natural extracellular matrix (ECM) conditions which support stem cell adhesion, proliferation and differentiation represent a main area of research in tissue engineering. Some of them successfully enhanced cells adhesion and proliferation because of their biocompatibility, biomimetic texture, and chemistry. However, it is still in its infancy, therefore intensification and optimization of in vitro, in vivo, and preclinical studies is needed to clarify efficacies as well as applicability of those bioengineered constructs. The aim of this review is to discuss mechanisms related to the in-vitro adhesion of MSCs, surfaces biochemical, biophysical, and other factors (of cell's natural and artificial micro-environment) which could affect it and a review of previous research attempting for its bio-chemo-optimization. - Highlights: • The main materials utilized for fabrication of biomimetic polymers are presented. • MSCs cell-material adhesion mechanism and involved molecules are reviewed. • Surface modifications of polymers in terms of MSC adhesion improving are discussed.

  19. Adhesion of mesenchymal stem cells to biomimetic polymers: A review

    International Nuclear Information System (INIS)

    Shotorbani, Behnaz Banimohamad; Alizadeh, Effat; Salehi, Roya; Barzegar, Abolfazl

    2017-01-01

    The mesenchymal stem cells (MSCs) are promising candidates for cell therapy due to the self-renewal, multi-potency, ethically approved state and suitability for autologous transplantation. However, key issue for isolation and manipulation of MSCs is adhesion in ex-vivo culture systems. Biomaterials engineered for mimicking natural extracellular matrix (ECM) conditions which support stem cell adhesion, proliferation and differentiation represent a main area of research in tissue engineering. Some of them successfully enhanced cells adhesion and proliferation because of their biocompatibility, biomimetic texture, and chemistry. However, it is still in its infancy, therefore intensification and optimization of in vitro, in vivo, and preclinical studies is needed to clarify efficacies as well as applicability of those bioengineered constructs. The aim of this review is to discuss mechanisms related to the in-vitro adhesion of MSCs, surfaces biochemical, biophysical, and other factors (of cell's natural and artificial micro-environment) which could affect it and a review of previous research attempting for its bio-chemo-optimization. - Highlights: • The main materials utilized for fabrication of biomimetic polymers are presented. • MSCs cell-material adhesion mechanism and involved molecules are reviewed. • Surface modifications of polymers in terms of MSC adhesion improving are discussed.

  20. Friction Material Composites Materials Perspective

    CERN Document Server

    Sundarkrishnaa, K L

    2012-01-01

    Friction Material Composites is the first of the five volumes which strongly educates and updates engineers and other professionals in braking industries, research and test labs. It explains besides the formulation of design processes and its complete manufacturing input. This book gives an idea of mechanisms of friction and how to control them by designing .The book is  useful for designers  of automotive, rail and aero industries for designing the brake systems effectively with the integration of friction material composite design which is critical. It clearly  emphasizes the driving  safety and how serious designers should  select the design input. The significance of friction material component like brake pad or a liner as an integral part of the brake system of vehicles is explained. AFM pictures at nanolevel illustrate broadly the explanations given.

  1. Analyzing the attributes of Indiana's STEM schools

    Science.gov (United States)

    Eltz, Jeremy

    "Primary and secondary schools do not seem able to produce enough students with the interest, motivation, knowledge, and skills they will need to compete and prosper in the emerging world" (National Academy of Sciences [NAS], 2007a, p. 94). This quote indicated that there are changing expectations for today's students which have ultimately led to new models of education, such as charters, online and blended programs, career and technical centers, and for the purposes of this research, STEM schools. STEM education as defined in this study is a non-traditional model of teaching and learning intended to "equip them [students] with critical thinking, problem solving, creative and collaborative skills, and ultimately establishes connections between the school, work place, community and the global economy" (Science Foundation Arizona, 2014, p. 1). Focusing on science, technology, engineering, and math (STEM) education is believed by many educational stakeholders to be the solution for the deficits many students hold as they move on to college and careers. The National Governors Association (NGA; 2011) believes that building STEM skills in the nation's students will lead to the ability to compete globally with a new workforce that has the capacity to innovate and will in turn spur economic growth. In order to accomplish the STEM model of education, a group of educators and business leaders from Indiana developed a comprehensive plan for STEM education as an option for schools to use in order to close this gap. This plan has been promoted by the Indiana Department of Education (IDOE, 2014a) with the goal of increasing STEM schools throughout Indiana. To determine what Indiana's elementary STEM schools are doing, this study analyzed two of the elementary schools that were certified STEM by the IDOE. This qualitative case study described the findings and themes from two elementary STEM schools. Specifically, the research looked at the vital components to accomplish STEM

  2. Update on small intestinal stem cells.

    Science.gov (United States)

    Tesori, Valentina; Puglisi, Maria Ausiliatrice; Lattanzi, Wanda; Gasbarrini, Giovanni Battista; Gasbarrini, Antonio

    2013-08-07

    Among somatic stem cells, those residing in the intestine represent a fascinating and poorly explored research field. Particularly, somatic stem cells reside in the small intestine at the level of the crypt base, in a constant balance between self-renewal and differentiation. Aim of the present review is to delve into the mechanisms that regulate the delicate equilibrium through which intestinal stem cells orchestrate intestinal architecture. To this aim, special focus will be addressed to identify the integrating signals from the surrounding niche, supporting a model whereby distinct cell populations facilitate homeostatic vs injury-induced regeneration.

  3. Stem cell migration - Methods and protocols

    Directory of Open Access Journals (Sweden)

    Carlo Alberto Redi

    2012-03-01

    Full Text Available The trafficking of stem cells is something unconsciously clear to any biologists (e.g., developmental biologists and physicians (e.g., all those taking care of hematopoietic and bone diseases and traumas; neverthless it is a phenomenon coming out as a hot topic just in these last years. Likely, the difficulties to track stem cells migration in vivo and the understanding of the elusive homing signals matching the circulating stem cells properties that makes these cells to stop and to start multiplication and differentiation....

  4. Bioreactor engineering of stem cell environments.

    Science.gov (United States)

    Tandon, Nina; Marolt, Darja; Cimetta, Elisa; Vunjak-Novakovic, Gordana

    2013-11-15

    Stem cells hold promise to revolutionize modern medicine by the development of new therapies, disease models and drug screening systems. Standard cell culture systems have limited biological relevance because they do not recapitulate the complex 3-dimensional interactions and biophysical cues that characterize the in vivo environment. In this review, we discuss the current advances in engineering stem cell environments using novel biomaterials and bioreactor technologies. We also reflect on the challenges the field is currently facing with regard to the translation of stem cell based therapies into the clinic. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Encouraging Creativity in a STEM Classroom

    Directory of Open Access Journals (Sweden)

    David L. Byrum

    2015-01-01

    Full Text Available The Thailand Ministry of Education’s “Institute for the Promotion of Teaching Science and Technology” (IPST uses the following as its working definition of STEM: “STEM education integrates science, engineering, technology and mathematics focusing on the application of knowledge to real-life problem solving and development of new products or procedures benefiting daily living and livelihood. STEM education infuses the engineering process into the existing science, mathematics and technology curricula to enable utilization of the knowledge to solve actual problems and aid future occupational undertakings.”

  6. Hematopoietic Stem Cell Transplantation and History

    Directory of Open Access Journals (Sweden)

    Atila Tanyeli

    2014-02-01

    Full Text Available Attemps to employ marrow stem cell for therapeutic purpose began in 1940’s. Marrow transplantation might be of use not only in irradiation protection, but also with therapeutic aim to marrow aplasia, leukemia and other diseases. The use and defining tissue antigens in humans were crucial to the improving of transplantation. The administration of methotrexate for GVHD improved the long term survival. Conditioning regimens for myeloablation designed according to diseases. Cord blood and peripheral blood stem cells were used for transplantion after 1980’s. Cord blood and bone marrow stem cell banks established to find HLA matched donor.

  7. Stemness-related markers in cancer

    Directory of Open Access Journals (Sweden)

    Wenxiu Zhao

    2017-01-01

    Full Text Available Cancer stem cells (CSCs, with their self-renewal ability and multilineage differentiation potential, are a critical subpopulation of tumor cells that can drive tumor initiation, growth, and resistance to therapy. Like embryonic and adult stem cells, CSCs express markers that are not expressed in normal somatic cells and are thus thought to contribute toward a “stemness” phenotype. This review summarizes the current knowledge of stemness-related markers in human cancers, with a particular focus on important transcription factors, protein surface markers, and signaling pathways.

  8. Concise Review: Quiescence in Adult Stem Cells

    DEFF Research Database (Denmark)

    Rumman, M; Dhawan, J; Kassem, Moustapha

    2015-01-01

    Adult stem cells (ASCs) are tissue resident stem cells responsible for tissue homeostasis and regeneration following injury. In uninjured tissues, ASCs exist in a nonproliferating, reversibly cell cycle-arrested state known as quiescence or G0. A key function of the quiescent state is to preserve...... stemness in ASCs by preventing precocious differentiation, and thus maintaining a pool of undifferentiated ASCs. Recent evidences suggest that quiescence is an actively maintained state and that excessive or defective quiescence may lead to compromised tissue regeneration or tumorigenesis. The aim...

  9. Characterisation of the surface topography, tomography and chemistry of fretting corrosion product found on retrieved polished femoral stems.

    Science.gov (United States)

    Bryant, M; Ward, M; Farrar, R; Freeman, R; Brummitt, K; Nolan, J; Neville, A

    2014-04-01

    This study presents the characterisation of the surface topography, tomography and chemistry of fretting corrosion product found on retrieved polished femoral stems. Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and Fourier Transform Infrared Spectroscopy (FI-IR) were utilised in order to assess the surface morphology of retrieved Metal-on-Metal Total Hip Replacements and surface chemistry of the films found on the surface. Gross slip, plastic deformation and directionality of the surface were extensively seen on the proximal surfaces of the retrievals. A more corrosive phenomenon was observed in the distal regions of the stem, demonstrating a seemingly intergranular attack. Tribochemical reactions were seen to occur within the stem-cement interfaces with tribofilms being observed on the femoral stem and counterpart PMMA bone cement. XPS, TEM-EDX and FT-IR analyses demonstrated that the films present in the stem surfaces were a complex mixture of chromium oxide and amorphous organic material. A comparison between current experimental and clinical literature has been conducted and findings from this study demonstrate that the formation and chemistry of films are drastically influenced by the type of wear or degradation mechanism. Films formed in the stem-cement interface are thought to further influence the biological environment outside the stem-cement interface due to the formation of Cr and O rich films within the interface whilst Co is free to migrate away. © 2013 Elsevier Ltd. All rights reserved.

  10. Stem cell clinics online: the direct-to-consumer portrayal of stem cell medicine.

    Science.gov (United States)

    Lau, Darren; Ogbogu, Ubaka; Taylor, Benjamin; Stafinski, Tania; Menon, Devidas; Caulfield, Timothy

    2008-12-04

    Despite the immature state of stem cell medicine, patients are seeking and accessing putative stem cell therapies in an "early market" in which direct-to-consumer advertising via the internet likely plays an important role. We analyzed stem cell clinic websites and appraised the relevant published clinical evidence of stem cell therapies to address three questions about the direct-to-consumer portrayal of stem cell medicine in this early market: What sorts of therapies are being offered? How are they portrayed? Is there clinical evidence to support the use of these therapies? We found that the portrayal of stem cell medicine on provider websites is optimistic and unsubstantiated by peer-reviewed literature.

  11. Muscle Stem Cells: A Model System for Adult Stem Cell Biology.

    Science.gov (United States)

    Cornelison, Ddw; Perdiguero, Eusebio

    2017-01-01

    Skeletal muscle stem cells, originally termed satellite cells for their position adjacent to differentiated muscle fibers, are absolutely required for the process of skeletal muscle repair and regeneration. In the last decade, satellite cells have become one of the most studied adult stem cell systems and have emerged as a standard model not only in the field of stem cell-driven tissue regeneration but also in stem cell dysfunction and aging. Here, we provide background in the field and discuss recent advances in our understanding of muscle stem cell function and dysfunction, particularly in the case of aging, and the potential involvement of muscle stem cells in genetic diseases such as the muscular dystrophies.

  12. A functional model for adult stem cells in epithelial tissues.

    NARCIS (Netherlands)

    Verstappen, J.; Katsaros, C.; Torensma, R.; Hoff, J.W. Von den

    2009-01-01

    Tissue turnover, regeneration, and repair take place throughout life. Stem cells are key players in these processes. The characteristics and niches of the stem cell populations in different tissues, and even in related tissues, vary extensively. In this review, stem cell differentiation and stem

  13. Inclusive STEM High Schools Increase Opportunities for Underrepresented Students

    Science.gov (United States)

    Spillane, Nancy K.; Lynch, Sharon J.; Ford, Michael R.

    2016-01-01

    The authors report on a study of eight inclusive STEM high schools that are designed to increase the numbers of students in demographic groups underrepresented in STEM. As STEM schools, they have had broader and deeper STEM coursework (taken by all students) than required by their respective states and school districts; they also had outcome…

  14. Stem Cell: Past, Present and Future- A Review Article | Avasthi ...

    African Journals Online (AJOL)

    Stem cells are basic cells of all multicellular organisms having the potency to differentiate into wide range of adult cells. Self renewal and totipotency are characteristic of stem cells. Though totipotency is shown by very early embryonic stem cells, the adult stem cells possess multipotency and differential plasticity which can ...

  15. 3 CFR - Guidelines for Human Stem Cell Research

    Science.gov (United States)

    2010-01-01

    ... 3 The President 1 2010-01-01 2010-01-01 false Guidelines for Human Stem Cell Research Presidential Documents Other Presidential Documents Memorandum of July 30, 2009 Guidelines for Human Stem Cell Research..., scientifically worthy human stem cell research, including human embryonic stem cell research, to the extent...

  16. Stem infection by dwarf mistletoe in California firs

    Science.gov (United States)

    John R. Parmeter; Robert F. Scharpf

    1982-01-01

    In fir stands infested with dwarf mistletoe (Arceuthobium abietinum Engelm. ex Munz.), the majority of susceptible understory trees had one or more stem infections. Most stem infections entered through infected branches and grew slowly around the stem, resulting in small amounts of decay or stem killing. Decay was not found in trees less than 50...

  17. Stem biomass and volume models of selected tropical tree species ...

    African Journals Online (AJOL)

    Stem biomass and stem volume were modelled as a function of diameter (at breast height; Dbh) and stem height (height to the crown base). Logarithmic models are presented that utilise Dbh and height data to predict tree component biomass and stem volumes. Alternative models are given that afford prediction based on ...

  18. Combined sequencing of mRNA and DNA from human embryonic stem cells

    Directory of Open Access Journals (Sweden)

    Florian Mertes

    2016-06-01

    Full Text Available Combined transcriptome and whole genome sequencing of the same ultra-low input sample down to single cells is a rapidly evolving approach for the analysis of rare cells. Besides stem cells, rare cells originating from tissues like tumor or biopsies, circulating tumor cells and cells from early embryonic development are under investigation. Herein we describe a universal method applicable for the analysis of minute amounts of sample material (150 to 200 cells derived from sub-colony structures from human embryonic stem cells. The protocol comprises the combined isolation and separate amplification of poly(A mRNA and whole genome DNA followed by next generation sequencing. Here we present a detailed description of the method developed and an overview of the results obtained for RNA and whole genome sequencing of human embryonic stem cells, sequencing data is available in the Gene Expression Omnibus (GEO database under accession number GSE69471.

  19. Diversity in the Stem Anatomy and Tissues of Several Species of Annona (Annonaceae in Nigeria

    Directory of Open Access Journals (Sweden)

    Abayomi Ezekiel FOLORUNSO

    2011-08-01

    Full Text Available Comparative study of the stem anatomy of Annona trees was carried out to facilitate identification of taxa when their reproductive parts are not available. Stem specimens of four out of the five species categorized as important under-utilized species were collected and subjected to anatomical studies. Macerated materials followed Schutze�s method of maceration and the transverse sections of the stem were cut using Reichert Sledge Microtome. Intrageneric characters observed are: epidermal layer uniseriate with round, oval to polygonal collenchyma cells. Wood is diffuse-porous, vessel elements are diffuse, vessels are of two types, that is, short/wide with simple pits and long/narrow with bordered pits. Diagnostic characters for the identification of each of the species are also reported.

  20. Diversity in the Stem Anatomy and Tissues of Several Species of Annona (Annonaceae in Nigeria

    Directory of Open Access Journals (Sweden)

    Abayomi Ezekiel FOLORUNSO

    2011-08-01

    Full Text Available Comparative study of the stem anatomy of Annona trees was carried out to facilitate identification of taxa when their reproductive parts are not available. Stem specimens of four out of the five species categorized as important under-utilized species were collected and subjected to anatomical studies. Macerated materials followed Schutzes method of maceration and the transverse sections of the stem were cut using Reichert Sledge Microtome. Intrageneric characters observed are: epidermal layer uniseriate with round, oval to polygonal collenchyma cells. Wood is diffuse-porous, vessel elements are diffuse, vessels are of two types, that is, short/wide with simple pits and long/narrow with bordered pits. Diagnostic characters for the identification of each of the species are also reported.