656 research outputs found
Hybrid CFRP-based strengthening technique to increase the flexural resistance and concrete confinement of RC columns submitted to axial and cyclic lateral loading
A strengthening technique that combines carbon fibre reinforced polymer (CFRP)
laminates and strips of wet lay-up CFRP sheet was used to increase the flexural resistance and the
energy dissipation capacity of square cross-section columns of very low concrete strength submitted
to constant axial compressive force and cyclic lateral loading. The laminates, applied according to the
Near Surface Mounted (NSM) technique, have the purpose of increasing the flexural resistance of the
columns, while the CFRP sheet installed as a localized jacket in the plastic hinge has the aim of
increasing the concrete confinement and avoid the buckling and the debonding of the laminates. In
spite of the 8 MPa of average concrete compressive strength used to manufacture the columns, the
hybrid strategy provided an average increase of about 46 % in terms of load carrying capacity, even
when applied in columns that had already been tested and presented intensives damages. The
experimental program is described and the main results are presented and analyzed
Acromion Clavicular Joint Reconstruction with LARS Ligament in Acute Dislocation
Background: The acromion clavicular joint dislocations are common injuries of the shoulder. The severity is dependent upon the degree of ligamentous injury. Surgical treatment is typically performed in higher grade acromioclavicular separation with several static and dynamic operative procedures with or without primary ligament replacement.
Methods: 47 patients with acute Rockwood type III, IV, and V injuries were treated surgically with LARS reconstruction. The success of technique was evaluated by radiographic outcomes for each patient at every follow-up visit (one,three, 12 months), while to assess pain reduction and clinical evaluation Visual Analogue scale score (VAS) and Constant-Murley score (CMA) was performed, respectively. An One Way Analysis of Variance (Kruskal-Wallis test), a multiple comparison Turket test, or a t-test (Mann-Whitney Rank Sum Test) were used when required.
Results: Follow-up radiographs revealed maintenance of anatomical reduction in 41 patients, and no bone erosions has been identified. In short-term joint functional recovery has been observed. Indeed, after 12 months pain on the VAS-scale in all groups decreased significantly (P < 0.05), and the CMS revealed a significant overall improvement (P < 0.05).
Conclusion: These data demonstrate that the use of the LARS allows to provide stability to the joint and especially to ensure its natural elasticity, relieving pain and improving joint function already one month post-surgery.
Level of evidence: II
Looking for Nano- and Microplastics in Meiofauna Using Advanced Methodologies
: Meiofauna (body size within 30ā1000 Āµm) are the community of microscopic invertebrates
that live at the bottom of marine and freshwater ecosystems and play a key role in the food webs
of these environments. Several studies have addressed the adverse effects of anthropic stressors on
meiofauna; however, data on the presence and impact of plastic debris in wild meiofaunal organisms
are scant. Since the amount of microplastic waste in sediments may surge rapidly, ascertaining the
ingestion of these xenobiotics by the abundant micrometazoan community is necessary to understand
their potential accumulation in aquatic food webs and their hazard to the health of the ecosystem.
The absence of documentation in this regard may be due to the difficulty in detecting the small size of
the plastic fragments meiofauna may potentially ingest. To overcome this difficulty, we developed an
integrated approach based on different microscopic/spectroscopic techniques suitable for detecting
plastic particles of sizes down to 200 nm.Meiofauna (body size within 30ā1000 m) are the community of microscopic invertebrates
that live at the bottom of marine and freshwater ecosystems and play a key role in the food webs
of these environments. Several studies have addressed the adverse effects of anthropic stressors on
meiofauna; however, data on the presence and impact of plastic debris in wild meiofaunal organisms
are scant. Since the amount of microplastic waste in sediments may surge rapidly, ascertaining the
ingestion of these xenobiotics by the abundant micrometazoan community is necessary to understand
their potential accumulation in aquatic food webs and their hazard to the health of the ecosystem.
The absence of documentation in this regard may be due to the difficulty in detecting the small size of
the plastic fragments meiofauna may potentially ingest. To overcome this difficulty, we developed an
integrated approach based on different microscopic/spectroscopic techniques suitable for detecting
plastic particles of sizes down to 200 nm
Regulation of Lipoprotein Lipase by Protein Kinase CĪ± in 3T3-F442A Adipocytes
Lipoprotein lipase (LPL) is an important enzyme in adipocyte and lipid metabolism with complex cellular regulation. Previous studies demonstrated an inhibition of LPL activity and synthesis following depletion of protein kinase C (PKC) isoforms with long term treatment of 3T3-F442A adipocytes with 12-O-tetradecanoylphorbol-13-acetate. To identify the specific PKC isoforms involved, we treated cells with antisense oligonucleotides that block expression of specific PKC isoforms. An antisense oligonucleotide to PKCĪ± inhibited LPL activity by 78 Ā± 8%, whereas antisense oligonucleotides directed against PKCĪ“ or PKCĪµ had no effect on LPL activity. The change in LPL activity was maximal at 72 h and was accompanied by a decrease in LPL protein and LPL synthetic rate but no change in LPL mRNA, suggesting regulation at the level of translation. However, PKC depletion resulted in no change in the polysome profile, indicating that translation initiation was not affected. However, the addition of cytoplasmic extracts from adipocytes treated with 12-O-tetradecanoylphorbol-13-acetate or PKCĪ± antisense oligomers inhibited LPL translation in vitro. This inhibition of LPL translation in vitro was lost when the LPL mRNA transcript did not contain nucleotides 1599-3200, thus implicating the 3ā²-untranslated region of LPL in the regulation of translation by PKC depletion. Both LPL activity and Raf1 activity were decreased in parallel following depletion of either total PKC or specific inhibition of PKCĪ±. An antisense oligonucleotide to RAF1, which inhibited RAF1 activity, also inhibited LPL activity by 48 Ā± 10%, and this decrease in LPL activity was not accompanied by a change in LPL mRNA. Cells were treated with U0126, a specific inhibitor of the ERK-activating kinases MEK1 and MEK2. Although U0126 inhibited ERK1 and ERK2 phosphorylation, U0126 had no effect on LPL activity, indicating that MEK/ERK pathways were not involved in this mechanism of LPL regulation. Together, these data indicate that PKCĪ± and RAF1 are important in the translational regulation of LPL in adipocytes and that the mechanism of regulation is probably through an ERK-independent pathway
Structural Characterization of Surfactant-Coated Bimetallic Cobalt/Nickel Nanoclusters by XPS, EXAFS, WAXS, and SAXS
Cobalt nickel bimetallic nanoparticles were synthesized by changing the sequence of the chemical reduction of Co(II) and Ni(II) ions confined in the core of bis(2-ethylhexyl)phosphate (2)., and Ni(DEHP)(2). The reduction was carried out by mixing, sequentially or contemporaneously, fixed amounts of n-heptane solution of Co(DEHP)2 and Ni(DEHP)2 micelles with a solution of sodium borohydride in ethanol at a fixed (reductant)/(total metal) molar ratio. This procedure involves the rapid formation of surfactant-coated nanoparticles, indicated as Co/Ni (Co after Ni), Ni/Co (Ni after Co), and Co + Ni (simultaneous), followed by their slow separation as nanostructures embedded in a sodium bis(2-ethylhexyl)phosphate matrix. The resulting composites, together with those obtained by reducing the n-heptane solutions of pure Co(DEHP)(2) or Ni(DEHP)(2), were characterized by XPS, EXAFS, WAXS, and SAXS. The data analysis confirms the presence of nanometer-sized surfactant-coated cobalt, nickel, and cobalt/nickel particles. As expected, the composition and internal structure of cobalt/nickel bimetallic nanoparticles are influenced by the preparation sequence as well as by the "chemical affinity" between the surfactant and the metal. However, some atomic-scale physicochemical processes play a subtle role in determining the structural features of bimetallic nanoparticles. Further effects due to the competition between nanoparticle growing process and surfactant adsorption at the nanoparticle surface were observed
Overcoming fears: a pathway to publishing for early career researchers
Purpose ā The purpose of this paper is to present reflections of five early career researchers on the
challenges of journal publishing and how to tackle them.
Design/methodology/approach ā The authors attended a participatory workshop on demystifying
academic publications. Working individually and in groups the authors shared, discussed, analysed,
visualised and ranked perceived challenges and opportunities concerning academic publishing. The authors
then delved into the existing literature on the subject. Following their enhanced understanding of the area, the
authors reflected on the experience and learnings.
Findings ā Personal confidence relating to the development of a scholarly identity was found to be a critical
factor in the attitude towards journal publishing. Supervisory and peer support, accessibility to journal editors,
as well as opportunities to reflect on the writing, publishing and peer review processes through participatory
workshops and writing groups, were deemed more effective than formal and conventional guidance schemes.
Research limitations/implications ā This work adds to the available literature regarding the issue of
academic publishing for PhD students and early career researchers.
Originality/value ā The paper contributes to a deeper understanding of issues surrounding publishing
apprehension, by laying out thoughts that are seldom expressed
U1 adaptors result in reduction of multiple pre-mRNA species principally by sequestering U1snRNP
U1 Adaptors are a recently reported novel approach for targeted reduction of mRNA transcripts. A U1 adaptor oligonucleotide comprising of a target-complimentary hybridization domain and a U1 recruitment domain, directs the U1 snRNP complex to the terminal exon of a targeted gene, subsequently inhibiting poly(A) tail addition and leading to degradation of that RNA species within the nucleus. Here, we present data demonstrating U1 adapter-mediated gene silencing can result in significant āoff-targetā silencing effects as demonstrated by the reduction of multiple mRNA species that were not intended to be targeted. Our data suggest that a substantial portion of this U1 adaptor-mediated off-target mRNA reduction is the result of sequestration U1 snRNP at levels sufficient to affect splicing and processing of non-target transcripts
- ā¦