208 research outputs found
Optimisation of different concrete mix designs for 3D Printing by utilising 6DOF industrial robot
Additive Manufacturing (AM) technologies are becoming increasingly viable for commercial and research implementation into various applications. AM refers to the process of forming structures layer upon layer and finds application in prototyping and manufacturing for building construction. It has recently begun to be considered as a viable and attractive alternative in certain circumstances in the construction industry. This paper focuses on the utilisation of different concrete mixtures paired with extrusion techniques facilitated by a six Degree of Freedom (DOF) industrial robot. Using methods of Damp Least Squares (DLS) in conjunction with Resolved Motion Rate Control (RMRC), it is possible to plan stable transitions between several waypoints representing the various print cross-sections. Calculated paths are projected via 'spline' interpolation into the manipulator controlled by custom software. This article demonstrates the properties of different concrete mixture designs, showing their performance when used as a filament in 3D Printing and representing a comparison of the results that were found. In this study, the prepared materials consist of ordinary Portland cement, fine sand between (425-450) micron, coarse aggregate ranges (3) mm and chemical admixtures which have been used to accelerate setting times and reduce water content. Numerous tests were performed to check the buildability, flowability, extrudability and moldability of the concrete mixtures. The horizontal test was used to determine the flowability and consistency, while the vertical and squeeze-flow tests were used to determine the buildability of the layers. The extrudability and moldability of the concrete mixtures were controlled by the robot and associated extruder speeds
Nuclear antisense effects in cyclophilin A pre‐mRNA splicing by oligonucleotides: a comparison of tricyclo‐DNA with LNA
The nuclear antisense properties of a series of tricyclo (tc)‐DNA oligonucleotide 9-15mers, targeted against the 3′ and 5′ splice sites of exon 4 of cyclophilin A (CyPA) pre‐mRNA, were evaluated in HeLa cells and compared with those of corresponding LNA‐oligonucleotides. While the 9mers showed no significant antisense effect, the 11-15mers induced exon 4 skipping and exon 3+4 double skipping to about an equal extent upon lipofectamine mediated transfection in a sequence‐ and dose‐dependent manner, as revealed by a RT-PCR assay. The antisense efficacy of the tc‐oligonucleotides was found to be superior to that of the LNA‐oligonucleotides in all cases by a factor of at least 4-5. A tc‐oligonucleotide 15mer completely abolished CyPA mRNA production at 0.2 µM concentration. The antisense effect was confirmed by western blot analysis which revealed a reduction in CyPA protein to 13% of its normal level. Fluorescence microscopic investigations with a fluorescein labeled tc‐15mer revealed a strong propensity for homogeneous nuclear localization of this backbone type after lipofectamine mediated transfection, while the corresponding lna 15mer showed a less clear cellular distribution pattern. Transfection without lipid carrier showed no significant internalization of both tc‐ and LNA‐ oligonucleotides. The obtained results confirm the power of tc‐DNA for nuclear antisense applications. Moreover, CyPA may become an interesting therapeutic target due to its important role in the early steps of the viral replication of HIV‐
an experimental approach with a trauma film paradigm
Background Intrusive memories of traumatic events are a core feature of post-
traumatic stress disorder but little is known about the neurobiological
formation of intrusions. The aim of this study was to determine whether the
activity of the noradrenergic system during an intrusion-inducing stressor
would influence subsequent intrusive memories. Method We conducted an
experimental, double-blind, placebo-controlled study in 118 healthy women.
Participants received a single dose of either 10 mg yohimbine, stimulating
noradrenergic activity, or 0.15 mg clonidine, inhibiting noradrenergic
activity, or placebo. Subsequently, they watched an established trauma film
which induced intrusions. The number of consecutive intrusions resulting from
the trauma film, the vividness of the intrusions, and the degree of distress
evoked by the intrusions were assessed during the following 4 days. Salivary
cortisol and α-amylase were collected before and after the trauma film.
Results A significant time × treatment interaction for the number of
intrusions and the vividness of intrusions indicated a different time course
of intrusions depending on treatment. Post-hoc tests revealed a delayed
decrease of intrusions and a delayed decrease of intrusion vividness after the
trauma film in the yohimbine group compared with the clonidine and placebo
groups. Furthermore, after yohimbine administration, a significant increase in
salivary cortisol levels was observed during the trauma film. Conclusions Our
findings indicate that pharmacological activation of the noradrenergic system
during an emotionally negative event makes an impact on consecutive intrusive
memories and their vividness in healthy women. The noradrenergic system seems
to be involved in the formation of intrusive memories
Future Challenges in Psychotherapy Research for Personality Disorders.
Individuals with personality disorders are frequently seen in mental health settings. Their symptoms typically reflect a high level of suffering and burden of disease, with potentially harmful societal consequences, including costs related to absenteeism at work, high use of health services, ineffective or harmful parenting, substance use, suicidal and non-suicidal self-harming behavior, and aggressiveness with legal consequences. Psychotherapy is currently the first-line treatment for patients with personality disorders, but the study of psychotherapy in the domain of personality disorders faces specific challenges.
Challenges include knowing what works for whom, identifying which putative mechanisms of change explain therapeutic effects, and including the social interaction context of patients with a personality disorder. By following a dimensional approach, psychotherapy research on personality disorders may serve as a model for the development and study of innovative psychotherapeutic interventions. We recommend developing the following: (a) an evidence base to make treatment decisions based on individual features; (b) a data-driven approach to predictors, moderators, and mechanisms of change in psychotherapy; (c) methods for studying the interaction between social context and psychotherapy
Position-dependent effects on stability in tricyclo-DNA modified oligonucleotide duplexes
A series of oligodeoxyribonucleotides and oligoribonucleotides containing single and multiple tricyclo(tc)-nucleosides in various arrangements were prepared and the thermal and thermodynamic transition profiles of duplexes with complementary DNA and RNA evaluated. Tc-residues aligned in a non-continuous fashion in an RNA strand significantly decrease affinity to complementary RNA and DNA, mostly as a consequence of a loss of pairing enthalpy ΔH. Arranging the tc-residues in a continuous fashion rescues Tm and leads to higher DNA and RNA affinity. Substitution of oligodeoxyribonucleotides in the same way causes much less differences in Tm when paired to complementary DNA and leads to substantial increases in Tm when paired to complementary RNA. CD-spectroscopic investigations in combination with molecular dynamics simulations of duplexes with single modifications show that tc-residues in the RNA backbone distinctly influence the conformation of the neighboring nucleotides forcing them into higher energy conformations, while tc-residues in the DNA backbone seem to have negligible influence on the nearest neighbor conformations. These results rationalize the observed affinity differences and are of relevance for the design of tc-DNA containing oligonucleotides for applications in antisense or RNAi therapy
Molecular detection of thyroglobulin mRNA transcripts in peripheral blood of patients with thyroid disease by RT-PCR
The sensitive detection of circulating tumour cells in patients with differentiated thyroid cancer may precede the detection of relapse by other diagnostic studies – such as serum thyroglobulin – and thus may have important therapeutic and prognostic implications. We performed reverse transcription-polymerase chain reaction (RT-PCR) on blood samples from patients diagnosed with thyroid disease using two different RT-PCR sensitivities. Additionally, tissue specificity of TG mRNA-expression was determined using RNA extracts from 27 different human tissues. The lower limit of detection was 50–100 TG mRNA producing cells/ml blood using a ‘normal’ RT-PCR sensitivity and 10–20 cells/ml blood using a ‘high’ sensitivity. With the normal sensitivity TG mRNA was detected in 9/13 patients with thyroid cancer and metastasis, 63/137 patients with a history of thyroid cancer and no metastasis, 21/85 with non-malignant thyroid disease and 9/50 controls. With the high sensitivity TG mRNA was detected in 11/13 patients with thyroid cancer and metastasis, 111/137 patients with a history of thyroid cancer and no metastasis, 61/85 with non-malignant thyroid disease and 41/50 controls. Interestingly, using the normal RT-PCR sensitivity TG mRNA transcripts are specific for thyroid tissue and detectable in the peripheral blood of controls and patients with thyroid disease, which correlates with a diagnosis of metastasized thyroid cancer. However, with a high RT-PCR sensitivity, TG mRNA expression was found not to be specific for thyroid tissue and was not correlated with a diagnosis of thyroid cancer in patients. As a consequence, to date TG mRNA detected by RT-PCR in the peripheral blood cannot be recommended as a tumour marker superior to TG serum-level. © 2000 Cancer Research Campaig
Expanding the Repertoire of Natural Product-Inspired Ring Pairs for Molecular Recognition of DNA
A furan amino acid, inspired by the recently discovered proximicin natural products, was incorporated into the scaffold of a DNA-binding hairpin polyamide. While unpaired oligomers of 2,4-disubstituted furan amino acids show poor DNA-binding activity, furan (Fn) carboxamides paired with N-methylpyrrole (Py) and N-methylimidazole (Im) rings demonstrate excellent stabilization of duplex DNA as well as discrimination of noncognate sequences, consistent with function as a Py mimic according to the Py/Im polyamide pairing rules
Automated systems in the identification and determination of methicillin resistance among coagulase negative staphylococci
Original article polymorphisms in CTNNBL1 in relation to colorectal cancer with evolutionary implications
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