Engineering molecular chains in carbon nanotubes

A range of mono- and bis-functionalised fullerenes have been synthesised and inserted into single-walled carbon nanotubes. The effect of the size and shape of the functional groups of the fullerenes on the resultant 1D arrays formed within the nanotubes was investigated by high resolution transmission electron microscopy and X-ray diffraction. The addition of non-planar, sterically bulky chains to the fullerene cage results in highly ordered 1D structures in which the fullerenes are evenly spaced along the internal nanotube cavity. Theoretical calculations reveal that the functional groups interact with neighbouring fullerene cages to space the fullerenes evenly within the confines of the nanotube. The addition of two functional groups to opposite sides of the fullerene cages results in a further increase in the separation of the fullerene cages within the nanotubes at the cost of lower nanotube filling rates.This work was financially supported by FWF project I83-N20 (ESF IMPrESS), the Royal Society, the European Research Council (ERC), "Fundacao para a Ciencia ea Tecnologia" through the program Ciencia 2008, the project SeARCH (Services and Advanced Research Computing with HTC/HPC clusters) and Nottingham Nanoscience and Nanotechnology Centre (NNNC)

Electrospun nanofibrous meshes cultured with Wharton’s Jelly Stem Cell: an alternative for cartilage regeneration, without the need of growth factors

Many efforts are being directed worldwide to the treatment of OA-focal lesions. The majority of those efforts comprise either the refinement of surgical techniques or combinations of biomaterials with various autologous cells. Herein, we tested electrospun polycaprolactone (PCL) nanofibrous meshes for cartilage tissue engineering. For that, articular chondrocytes (hACs) isolated from human osteoarthritic joints and Whartonâ s Jelly Stem Cells (hWJSCs) are cultured on electrospun nanofiber meshes, without adding external growth factors. We observed higher glycosaminoglycans production and higher overexpression of cartilage-related genes from hWJSCs cultured with basal medium, when compared to hACs isolated from osteoarthritic joints. Moreover, the presence of sulfated proteoglycans and collagen type II is observed on both types of cell cultures. We believe that this effect is due to either the electrospun nanofibers topography or the intrinsic chondrogenic differentiation potential of hWJSCs. Therefore, we propose the electrospun nanofibrous scaffolds in combination with hWJSCs as a viable alternative to the commercial membranes used in autologous chondrogenic regeneration approaches.The authors thank the Portuguese Foundation for Science and Technology for the Post-Doc grant of Marta Alves da Silva (SFRH/BPD/73322/2010, financed by POPH QREN Tipologia 4.1 – Advanced Formation, co-financed by Fundo Social Europeu and MEC national funds). This work was supported by the project SPARTAN (PTDC/CTM-BIO/4388/2014) FCT/MEC with PIDDAC funds. It was also partly supported by the POLARIS (FP7-REGPOT-2012-2013-1) and the Project “New methodologies for the isolation and control of stem cells differentiation using advanced culturing conditions and/or nanomaterials” (RL2 SCN NORTE-01-0124-FEDER-000018), co-financed by North Portugal Regional Operational Programme (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio

Emerging Infectious Disease leads to Rapid Population Decline of Common British Birds

Emerging infectious diseases are increasingly cited as threats to wildlife, livestock and humans alike. They can threaten geographically isolated or critically endangered wildlife populations; however, relatively few studies have clearly demonstrated the extent to which emerging diseases can impact populations of common wildlife species. Here, we report the impact of an emerging protozoal disease on British populations of greenfinch Carduelis chloris and chaffinch Fringilla coelebs, two of the most common birds in Britain. Morphological and molecular analyses showed this to be due to Trichomonas gallinae. Trichomonosis emerged as a novel fatal disease of finches in Britain in 2005 and rapidly became epidemic within greenfinch, and to a lesser extent chaffinch, populations in 2006. By 2007, breeding populations of greenfinches and chaffinches in the geographic region of highest disease incidence had decreased by 35% and 21% respectively, representing mortality in excess of half a million birds. In contrast, declines were less pronounced or absent in these species in regions where the disease was found in intermediate or low incidence. Also, populations of dunnock Prunella modularis, which similarly feeds in gardens, but in which T. gallinae was rarely recorded, did not decline. This is the first trichomonosis epidemic reported in the scientific literature to negatively impact populations of free-ranging non-columbiform species, and such levels of mortality and decline due to an emerging infectious disease are unprecedented in British wild bird populations. This disease emergence event demonstrates the potential for a protozoan parasite to jump avian host taxonomic groups with dramatic effect over a short time period

Application of crystallising hydrophobic mineral and curing agent to fresh concrete

Whilst the use of curing agents is common practice in the production of reinforced concrete, it is not normal to apply protective treatments to freshly cast concrete. Such treatments, which are generally hydrophobic in nature, are commonly applied to matured concrete, as protection against chloride and water absorption and associated cyclic freeze thaw attack. One gateway issue in respect to the application of such surface treatments to fresh concrete, is its unavoidably high moisture content, which is known to substantially downgrade the effectiveness of silane and siloxane hydrophobic treatments. The possibility of protectively treating fresh concrete is interesting from the logistic and economic standpoints, in the matter of early completion of on-site works. Towards this advantageous position, it is interesting to observe that early surface treatment with a crystallising hydrophobic mineral solution, immediately followed by a curing agent application, safeguards the 28 day strength of concrete in an extremely adverse curing environment. Added to this, the treated concrete sorptivity values with protected curing and the adverse curing regime, are similar, indicating that concrete durability may also be protected by the combined surface treatment, applied as early as 3 hours following casting

Attitude toward contraception and abortion among Curaçao women. Ineffective contraception due to limited sexual education?

Background In Curaçao is a high incidence of unintended pregnancies and induced abortions. Most of the induced abortions in Curaçao are on request of the woman and performed by general practitioners. In Curaçao, induced abortion is strictly prohibited, but since 1999 there has been a policy of connivance. We present data on the relevance of economic and socio-cultural factors for the high abortion-rates and the ineffective use of contraception. Methods Structured interviews to investigate knowledge and attitudes toward sexuality, contraception and abortion and reasons for ineffective use of contraceptives among women, visiting general practitioners. Results Of 158 women, 146 (92%) participated and 82% reported that their education on sexuality and about contraception was of good quality. However 'knowledge of reliable contraceptive methods' appeared to be - in almost 50% of the cases - false information, misjudgements or erroneous views on the chance of getting pregnant using coitus interruptus and about the reliability and health effects of oral contraceptive pills. Almost half of the interviewed women had incorrect or no knowledge about reliability of condom use and IUD. 42% of the respondents risked by their behavior an unplanned pregnancy. Most respondents considered abortion as an emergency procedure, not as contraception. Almost two third experienced emotional, physical or social problems after the abortion. Conclusions Respondents had a negative attitude toward reliable contraceptives due to socio-cultural determined ideas about health consequences and limited sexual education. Main economic factors were costs of contraceptive methods, because most health insurances in Curaçao do not cover contraceptives. To improve the effective use of reliable contraceptives, more adequate information should be given, targeting the wrong beliefs and false information. The government should encourage health insurance companies to reimburse contraceptives. Furthermore, improvement of counseling during the abortion procedure is important

Response characteristics in the apex of the gerbil cochlea studied through auditory nerve recordings

In this study, we analyze the processing of low-frequency sounds in the cochlear apex through responses of auditory nerve fibers (ANFs) that innervate the apex. Single tones and irregularly spaced tone complexes were used to evoke ANF responses in Mongolian gerbil. The spike arrival times were analyzed in terms of phase locking, peripheral frequency selectivity, group delays, and the nonlinear effects of sound pressure level (SPL). Phase locking to single tones was similar to that in cat. Vector strength was maximal for stimulus frequencies around 500 Hz, decreased above 1 kHz, and became insignificant above 4 to 5 kHz. We used the responses to tone complexes to determine amplitude and phase curves of ANFs having a characteristic frequency (CF) below 5 kHz. With increasing CF, amplitude curves gradually changed from broadly tuned and asymmetric with a steep low-frequency flank to more sharply tuned and asymmetric with a steep high-frequency flank. Over the same CF range, phase curves gradually changed from a concave-upward shape to a concave-downward shape. Phase curves consisted of two or three approximately straight segments. Group delay was analyzed separately for these segments. Generally, the largest group delay was observed near CF. With increasing SPL, most amplitude curves broadened, sometimes accompanied by a downward shift of best frequency, and group delay changed along the entire range of stimulus frequencies. We observed considerable across-ANF variation in the effects of SPL on both amplitude and phase. Overall, our data suggest that mechanical responses in the apex of the cochlea are considerably nonlinear and that these nonlinearities are of a different character than those known from the base of the cochlea

The expression of creativity in learning how to read and write : a case study

O presente artigo tem por objetivo destacar as formas em que a criatividade se expressa na aprendizagem da leitura e da escrita da criança. Assume-se como referencial teórico a concepção de aprendizagem criativa desenvolvida por Mitjáns Martínez. Segundo essa concepção, os processos criativos emergem nos contextos de ação do sujeito, mediante recursos subjetivos constituídos historicamente e que se organizam no momento da ação concreta. A expressão desse tipo de aprendizagem tem se configurado pela personalização da informação, confrontação com o dado e pela geração, produção de ideias novas que vão além do que está posto. Adota-se como eixo norteador a pesquisa qualitativa, apoiada nos princípios da epistemologia qualitativa desenvolvida por González Rey, com opção pelo estudo de caso utilizando instrumentos abertos e semiabertos, tais como: dinâmicas conversacionais, observações, entrevistas como processo e diário de ideias. A investigação foi desenvolvida em uma escola da rede pública, com alunos dos primeiros e segundos anos do ensino fundamental, na qual acompanhamos os aprendizes por dois anos consecutivos. Como conclusão, considera-se que a expressão da criatividade na aprendizagem da leitura e da escrita foi significativamente apresentada pelas características destacadas por Mitjáns Martínez, bem como pela relação lúdica da criança com sua aprendizagem.This paper has the purpose of highlighting the ways through which creativity is expressed in the child´s learning of how to read and write. The theoretical assumption taken is the concept of creative learning developed by Mitjáns Martínez. According to such conception, the creative processes emerge in the context of the individual´s action, through subjective resources that are historically constructed and are organized in the moment of concrete action. The expression of this type of learning has been configured by the personalization of information, confrontation with the data, and by the generation and production of new ideas that go beyond what is taken for granted. The guiding axis adopted is qualitative research, supported by the principles of thequalitative epistemology developed by González Rey, with the option of conducting a case study utilizing open and semi-open tools, such as: conversational dynamics, observations, interviews as a process and a diary of ideas. The investigation took place in a public school, among 1st and 2nd graders, in which we monitored the learners for two years in a row. As a conclusion, we consider that the expression of creativity in learning how to read and write was significantly presented by the characteristics emphasized by the author mentioned above, as well as by the playful relationship of the child with his/her learning

Systemic AAV vectors for widespread and targeted gene delivery in rodents

We recently developed adeno-associated virus (AAV) capsids to facilitate efficient and noninvasive gene transfer to the central and peripheral nervous systems. However, a detailed protocol for generating and systemically delivering novel AAV variants was not previously available. In this protocol, we describe how to produce and intravenously administer AAVs to adult mice to specifically label and/or genetically manipulate cells in the nervous system and organs, including the heart. The procedure comprises three separate stages: AAV production, intravenous delivery, and evaluation of transgene expression. The protocol spans 8 d, excluding the time required to assess gene expression, and can be readily adopted by researchers with basic molecular biology, cell culture, and animal work experience. We provide guidelines for experimental design and choice of the capsid, cargo, and viral dose appropriate for the experimental aims. The procedures outlined here are adaptable to diverse biomedical applications, from anatomical and functional mapping to gene expression, silencing, and editing

Optimum mix design for internally integrated concrete with crystallising protective material

In this research, a silica-based crystallizing protective material was integrated into a fresh concrete mix to evaluate its efficacy in reducing water absorption while preserving the compressive strength level of the mixture. An optimum concrete mix design was determined, by producing several concrete mixes with different water-to-cement ratios (w/c) of 0.32, 0.37, 0.40, and 0.46, and treated with 2% and 4% of the crystallizing admixture. Water absorption and the mechanical properties of the treated and control mixes were measured, using the initial surface absorption test (ISAT) and the compressive strength and the flexural strength tests, respectively. Results showed that it is possible to obtain a water-resistant concrete without compromising its compressive strength if the right w/c ratio was used and the proper dosage of the crystallizing material was added. In addition, results revealed that treatment is beneficial only in the case of producing concrete with low w/c ratios of 0.32 and 0.37 and treated with crystallizing material. The compressive strength can increase up to 42% and with a significant drop in water absorption reaches 65%. Treated concrete was analyzed thoroughly under the scanning electron microscope (SEM) and X-ray diffraction (XRD) instrument to show the development of crystals with time and their interaction with the concrete mix

Towards the design of 3D multiscale instructive tissue engineering constructs: Current approaches and trends

The design of 3D constructs with adequate properties to instruct and guide cells both in vitro and in vivo is one of the major focuses of tissue engineering. Successful tissue regeneration depends on the favorable crosstalk between the supporting structure, the cells and the host tissue so that a balanced matrix production and degradation is achieved. Herein, the major occurring events and players in normal and regenerative tissue are overviewed. These have been inspiring the selection or synthesis of instructive cues to include into the 3D constructs. We further highlight the importance of a multiscale perception of the range of features that can be included on the biomimetic structures. Lastly, we focus on the current and developing tissue-engineering approaches for the preparation of such 3D constructs: top-down, bottom-up and integrative. Bottom-up and integrative approaches present a higher potential for the design of tissue engineering devices with multiscale features and higher biochemichal control than top-down strategies, and are the main focus of this review.The research leading to these results has received funding from the European Research Council grant agreement ERC-2012-ADG-20120216-321266 for the project ComplexiTE. Portuguese Foundation for Science and Technology is gratefully acknowledged for the fellowship of Sara M. Oliveira (SFRH/BD/70107/2010)