245 research outputs found
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Leaf-inspired microcontact printing vascular patterns.
The vascularization of tissue grafts is critical for maintaining viability of the cells within a transplanted graft. A number of strategies are currently being investigated including very promising microfluidics systems. Here, we explored the potential for generating a vasculature-patterned endothelial cells that could be integrated into distinct layers between sheets of primary cells. Bioinspired from the leaf veins, we generated a reverse mold with a fractal vascular-branching pattern that models the unique spatial arrangement over multiple length scales that precisely mimic branching vasculature. By coating the reverse mold with 50 μg ml-1 of fibronectin and stamping enabled selective adhesion of the human umbilical vein endothelial cells (HUVECs) to the patterned adhesive matrix, we show that a vascular-branching pattern can be transferred by microcontact printing. Moreover, this pattern can be maintained and transferred to a 3D hydrogel matrix and remains stable for up to 4 d. After 4 d, HUVECs can be observed migrating and sprouting into Matrigel. These printed vascular branching patterns, especially after transfer to 3D hydrogels, provide a viable alternative strategy to the prevascularization of complex tissues
The Human-Animal Bond, Human Social Support and Resilience: Understanding Relationships that Aid Through Adversity
The Human-Animal Bond (HAB) has been shown to provide a buffering effect for
stress and adversity. Based on gaps within the literature, this thesis takes a strengths-based
approach to investigating the HAB, human social support and resilience, a construct not
previously explored within the HAB field of research. This thesis builds upon previous
findings that social support is a protective factor for resilience by investigating whether the
HAB may be comparable with human social support. Given research into the HAB reported
on the complexities of the HAB and associated methodological limitations, this thesis aims to
produce outcomes based on methodological rigour and a theoretical framework that
emphasises the strength of the bond as having an impact on mental health outcomes.
Utilising a mixed methods research design, the thesis is comprised of two quantitative
studies and one qualitative study. A two-way approach with follow-up exploratory design
enhances the credibility and validity of the outcomes and improves upon the research
methodologies used within the HAB field of research. The first study of this thesis examines
a large sample (N = 538) of companion animal owners and non-owners to determine whether
the HAB would moderate the relationship between human social support and resilience, and
whether the relationship between the HAB and human social support may be curvilinear.
That was followed by a descriptive study to establish what subpopulation most likely had low
to moderate levels of human social support and strong HAB, and was therefore potentially at
risk of lower levels of resilience. Finally, a subpopulation of women was explored to
understand the comparability of their animal companion and human relationships, as well as
whether their companion animals aided through adversity.
Study One was a rigorous cross-sectional study that found the HAB was not a
significant moderator between levels of human social support and resilience for companion animal owners. However, there was a significant curvilinear relationship between the HAB
and perceived human social support, suggesting extremely weak or strong HABs may be
correlated with a reduced capacity to build resilience and process adversity. The dataset from
Study One was further explored for Study Two and found single women were more likely to
have low to moderate human social support and strong bonds with their companion animals.
Study Three was a qualitative study that explored women who recorded scores of low
to moderate levels of human social support and strong HAB. Semi-structured interviews were
conducted with seven women and thematically analysed, finding that women preferred their
companion animals over their human social supports, that companion animals provided
strong emotional support and were considered a strong protective factor in supporting women
through adversity and against suicide.
Despite some methodological limitations in this thesis, it contributes knowledge to the
HAB literature base, including alternative explanations as to how outcome measures are
interpreted, such as finding a curvilinear relationship between the HAB and human social
support (Hill et al, 2020), as well as understanding women companion animal owners’
relationships. The mixed methodological approach utilised in this thesis has implication for
the HAB field of research to consider similar research design and improve upon reported
methodological weaknesses. The implications for mental health clinicians providing
therapeutic care to individuals experiencing adversity, particularly suicidality, are significant.Thesis (Ph.D.) -- University of Adelaide, School of Psychology, 202
The impact of growing season and cultivation systems on the dissipation of profenofos and λ‑ cyhalothrin on Brassica juncea:a comparative study
This study was conducted to contour dissipation patterns of two pesticides (profenofos and λ-cyhalothrin) on B. juncea
(green mustard) grown under green house (G.H.) and open field (O.F.) during dry and wet season. The dissipation data
of studied pesticides were fitted into the first order kinetic equation. Based on the dissipation rate constant, k obtained, profenofos dissipates faster than λ-cyhalothrin regardless of growing system and season. The dissipation of both pesticides were found to be more rapid during dry season compare to wet season. Growing system however displayed a rather contradictory results for profenofos where during dry season, faster dissipation took place in O.F., while during wet season rapid dissipation took place in G.H. λ-Cyhalothrin on the other hand exhibits faster dissipation in G.H. during both seasons. The half-lives obtained for profenofos and λ-cyhalothrin in B. juncea were 0.66–1.8 days and 1.18–3.7 days, respectively. Based on this experiment, terminal residue obtained for profenofos and λ-cyhalothrin for B. juncea were lower than the stipulated MRL. This work was momentous to guide appropriate applications and establishment of accurate PHI of pesticides in B. juncea that will benefit farmers in a country with humid tropical climate
The genome of the largest bony fish, ocean sunfish (<i>Mola mola</i>), provides insights into its fast growth rate
BACKGROUND: The ocean sunfish (Mola mola), which can grow up to a length of 2.7 m and weigh 2.3 tons, is the world’s largest bony fish. It has an extremely fast growth rate and its endoskeleton is mainly composed of cartilage. Another unique feature of the sunfish is its lack of a caudal fin, which is replaced by a broad and stiff lobe that results in the characteristic truncated appearance of the fish. RESULTS: To gain insights into the genomic basis of these phenotypic traits, we sequenced the sunfish genome and performed a comparative analysis with other teleost genomes. Several sunfish genes involved in the growth hormone and insulin-like growth factor 1 (GH/IGF1) axis signalling pathway were found to be under positive selection or accelerated evolution, which might explain its fast growth rate and large body size. A number of genes associated with the extracellular matrix, some of which are involved in the regulation of bone and cartilage development, have also undergone positive selection or accelerated evolution. A comparison of the sunfish genome with that of the pufferfish (fugu), which has a caudal fin, revealed that the sunfish contains more homeobox (Hox) genes although both genomes contain seven Hox clusters. Thus, caudal fin loss in sunfish is not associated with the loss of a specific Hox gene. CONCLUSIONS: Our analyses provide insights into the molecular basis of the fast growth rate and large size of the ocean sunfish. The high-quality genome assembly generated in this study should facilitate further studies of this ‘natural mutant’. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13742-016-0144-3) contains supplementary material, which is available to authorized users
Graphene-Based Electromechanical Thermal Switches
Thermal management is an important challenge in modern electronics, avionics,
automotive, and energy storage systems. While passive thermal solutions (like
heat sinks or heat spreaders) are often used, actively modulating heat flow
(e.g. via thermal switches or diodes) would offer additional degrees of control
over the management of thermal transients and system reliability. Here we
report the first thermal switch based on a flexible, collapsible graphene
membrane, with low operating voltage, < 2 V. We also employ active-mode
scanning thermal microscopy (SThM) to measure the device behavior and switching
in real time. A compact analytical thermal model is developed for the general
case of a thermal switch based on a double-clamped suspended membrane,
highlighting the thermal and electrical design challenges. System-level
modeling demonstrates the thermal trade-offs between modulating temperature
swing and average temperature as a function of switching ratio. These
graphene-based thermal switches present new opportunities for active control of
fast (even nanosecond) thermal transients in densely integrated systems
CK2 inhibitor CX-4945 destabilizes NOTCH1 and synergizes with JQ1 against human T-acute lymphoblastic leukemic cells
Here we show that CK2 inhibition by CX-4945 destabilizes NOTCH1 and synergizes with JQ1 to induce apoptosis in human T-ALL cells, implicating an alternative strategy to target NOTCH1 signaling in refractory/relapsed T-ALL
Development of a single-chain fragment variable fused-mutant HALT-1 recombinant immunotoxin against G12V mutated KRAS colorectal cancer cells
Background: KRAS oncogenes harboring codon G12 and G13 substitutions are considered gatekeeper mutations which drive oncogenesis in many cancers. To date, there are still no target-specific vaccines or drugs available against this genotype, thus reinforcing the need towards the development of targeted therapies such as immunotoxins. Methods: This study aims to develop a recombinant anti-mKRAS scFv-fused mutant Hydra actinoporin-like-toxin-1 (mHALT-1) immunotoxin that is capable of recognizing and eradicating codon-12 mutated k-ras antigen abnormal cells. One G13D peptide mimotope (164-D) and one G12V peptide mimotope (68-V) were designed to elicit antigen specific IgG titres against mutated K-ras antigens in immunised Balb/c mice. The RNA was extracted from splenocytes following ELISA confirmation on post-immunized mice sera and was reverse transcribed into cDNA. The scFv combinatorial library was constructed from cDNA repertoire of variable regions of heavy chain (VH) and light chain (VL) fusions connected by a flexible glycine-serine linker, using splicing by overlap extension PCR (SOE-PCR). Anti-mKRAS G12V and G13D scFvs were cloned in pCANTAB5E phagemid and superinfected with helper phage. After few rounds of bio-panning, a specific mKRAS G12V and G13D scFv antibody against G12V and G13D control mimotope was identified and confirmed using ELISA without any cross-reactivity with other mimotopes or controls. Subsequently, the anti-mKRAS scFv was fused to mHALT-1 using SOE-PCR and cloned in pET22b vector. Expressed recombinant immunotoxins were analyzed for their effects on cell proliferation by the MTT assay and targeted specificity by cell-based ELISA on KRAS-positive and KRAS-negative cancer cells. Results: The VH and VL genes from spleen RNA of mice immunized with 164-D and 68-V were amplified and randomly linked together, using SOE-PCR producing band sizes about 750 bp. Anti-mKRAS G12V and G13D scFvs were constructed in phagemid pCANTAB5E vectors with a library containing 3.4 × 106 and 2.9 × 106 individual clones, respectively. After three rounds of bio-panning, the anti-mKRAS G12V-34 scFv antibody against G12V control mimotope was identified and confirmed without any cross-reactivity with other controls using ELISA. Anti-mKRAS G12V-34 scFv fragment was fused to mHALT-1 toxin and cloned in pET22b vector with expression as inclusion bodies in E. coli BL21(DE3) (molecular weight of ~46.8 kDa). After successful solubilization and refolding, the mHALT-1-scFv immunotoxin exhibited cytotoxic effects on SW-480 colorectal cancer cells with IC50 of 25.39 μg/mL, with minimal cytotoxicity effect on NHDF cells. Discussion: These results suggested that the development of such immunotoxins is potentially useful as an immunotherapeutic application against KRAS-positive malignancies
Valorisation of crustacean and bivalve processing side streams for industrial fast time-to-market products: A review from the European Union regulation perspective
A massive amount of crustaceans and bivalves are consumed each year, leading to millions of tons of processing side streams from the seafood industry. Considering the current trend of (bio)circular and zero-waste food production, crustacean and bivalve processing side streams (CBPS) seem a promising and emerging resource for producing high-value-added products. This paper highlights the general composition of CBPS with high commercial values, namely, protein, lipids, carotenoids, minerals and chitins. The extraction strategies of these fractions, including conventional chemical and environmentally friendly methods, are also discussed. This review presents and summarises CBPS as raw materials for developing fast time-to-market products complying with specific EU regulations, including animal feeds, bio-pesticide/stimulants, and cosmetic ingredients. This paper also provides insights into challenges of applying CBPS as raw materials to generate products for human consumption
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