5,523 research outputs found
Perineuronal chondroitin sulfates and semaphorin 3A regulate postnatal maturation of the vestibular circuit for gravity detection
Conference Theme: The Extracellular Matrix NichePoster Presentation: abstract no. P30Perineuronal chondroitin sulfate proteoglycan networks are implicated in restricting plasticity of the
mature CNS. Less is known of the impact of ligands associated with the perineuronal network (PN) in
the formative period of neural circuits. The emergence of negative geotaxis with postnatal maturation
of the vestibular circuitry for gravity detection offers a behavioral readout in tests for roles of the PN
and associated ligands in vestibular plasticity. Using postnatal rats as model, we found that negative
geotaxis was mature by postnatal day (P) 9, in correlation with ...postprin
Semaphorin3A, associated with perineuronal nets, regulates the development of the maturation of the central vestibular circuitry
Poster Presentation - Theme 5: NeuroscienceDuring the formative period of neural circuits, perineuronal nets (PN) are established to restrict plasticity of the circuit. The role of PN in vestibular plasticity can be tested by studying the emergence of negative geotaxis with postnatal maturation of the vestibular circuitry for gravity detection.
Using rats as model, we observed that negative geotaxis was mature by postnatal day (P) 9, in correlation with consolidation of PN around GABAergic neurons …postprin
The use of enoxaparin in Chinese patients undergoing percutaneous coronary intervention: observations on safety, efficacy, and pharmacokinetics from a pilot study
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Protocol for a systematic review and thematic synthesis of patient experiences of central venous access devices in anti-cancer treatment
Background:
Three types of central venous access devices (CVADs)—peripherally inserted central catheters (PICCs), skin-tunnelled central catheters (Hickman-type devices), and implantable chest wall Ports (Ports)—are routinely used in the intravenous administration of anti-cancer treatment. These devices avoid the need for peripheral cannulation and allow for home delivery of treatment. Assessments of these devices have tended to focus on medical and economic factors, but there is increased interest in the importance of patient experiences and perspectives in this area. The aim of this systematic review is to synthesise existing research regarding patient experiences of these CVADs to help clinicians guide, prepare, and support patients receiving CVADs for the administration of anti-cancer treatment.
Method:
A systematic search of MEDLINE, Embase, and CINAHL research databases will be carried out along with a supplementary reference list search. This review will include quantitative, qualitative, and mixed methods studies published in peer-review journals, reporting some aspect(s) of patient experiences or perspectives regarding the use of PICC, Hickman, or Port CVADs for the administration of anti-cancer drugs. The methodological quality and risk of bias of included papers will be assessed using the Mixed Methods Appraisal Tool (MMAT). Relevant outcome data will be extracted from included studies and analysed using a thematic synthesis approach.
Discussion:
The results section of the review will comprise thematic synthesis of quantitative studies, thematic synthesis of qualitative studies, and the aggregation of the two. Results will aim to offer an account of current understandings of patient experiences and perspective regarding PICC, Hickman-type, and Port devices in the context of anti-cancer treatment. Confidence in cumulative evidence will be assessed using the Confidence in the Evidence from Reviews of Qualitative research (CERQual) approach
Changes in midbrain pain receptor expression, gait and behavioral sensitivity in a rat model of radiculopathy.
Intervertebral disc herniation may contribute to inflammatory processes that associate with radicular pain and motor deficits. Molecular changes at the affected dorsal root ganglion (DRG), spinal cord, and even midbrain, have been documented in rat models of radiculopathy or nerve injury. The objective of this study was to evaluate gait and the expression of key pain receptors in the midbrain in a rodent model of radiculopathy. Radiculopathy was induced by harvesting tail nucleus pulposus (NP) and placing upon the right L5 DRG in rats (NP-treated, n=12). Tail NP was discarded in sham-operated animals (n=12). Mechanical allodynia, weight-bearing, and gait were evaluated in all animals over time. At 1 and 4 weeks after surgery, astrocyte and microglial activation was tested in DRG sections. Midbrain sections were similarly evaluated for immunoreactivity to serotonin (5HT(2B)), mu-opioid (µ-OR), and metabotropic glutamate (mGluR4 and 5) receptor antibodies. NP-treated animals placed less weight on the affected limb 1 week after surgery and experienced mechanical hypersensitivity over the duration of the study. Astroctye activation was observed at DRGs only at 4 weeks after surgery. Findings for pain receptors in the midbrain of NP-treated rats included an increased expression of 5HT(2B) at 1, but not 4 weeks; increased expression of µ-OR and mGluR5 at 1 and 4 weeks (periaqueductal gray region only); and no changes in expression of mGluR4 at any point in this study. These observations provide support for the hypothesis that the midbrain responds to DRG injury with a transient change in receptors regulating pain responses
Gauge fields in (A)dS within the unfolded approach: algebraic aspects
It has recently been shown that generalized connections of the (A)dS space
symmetry algebra provide an effective geometric and algebraic framework for all
types of gauge fields in (A)dS, both for massless and partially-massless. The
equations of motion are equipped with a nilpotent operator called
whose cohomology groups correspond to the dynamically relevant quantities like
differential gauge parameters, dynamical fields, gauge invariant field
equations, Bianchi identities etc. In the paper the -cohomology is
computed for all gauge theories of this type and the field-theoretical
interpretation is discussed. In the simplest cases the -cohomology is
equivalent to the ordinary Lie algebra cohomology.Comment: 59 pages, replaced with revised verio
Ordinary-derivative formulation of conformal totally symmetric arbitrary spin bosonic fields
Conformal totally symmetric arbitrary spin bosonic fields in flat space-time
of even dimension greater than or equal to four are studied. Second-derivative
(ordinary-derivative) formulation for such fields is developed. We obtain gauge
invariant Lagrangian and the corresponding gauge transformations. Gauge
symmetries are realized by involving the Stueckelberg and auxiliary fields.
Realization of global conformal boost symmetries on conformal gauge fields is
obtained. Modified de Donder gauge condition and de Donder-Stueckelberg gauge
condition are introduced. Using the de Donder-Stueckelberg gauge frame,
equivalence of the ordinary-derivative and higher-derivative approaches is
demonstrated. On-shell degrees of freedom of the arbitrary spin conformal field
are analyzed. Ordinary-derivative light-cone gauge Lagrangian of conformal
fields is also presented. Interrelations between the ordinary-derivative gauge
invariant formulation of conformal fields and the gauge invariant formulation
of massive fields are discussed.Comment: 51 pages, v2: Results and conclusions of v1 unchanged. In Sec.3,
brief review of higher-derivative approaches added. In Sec.4, new
representations for Lagrangian, modified de Donder gauge, and de
Donder-Stueckelberg gauge added. In Sec.5, discussion of interrelations
between the ordinary-derivative and higher-derivative approaches added.
Appendices A,B,C,D and references adde
Gene expression drives the evolution of dominance.
Dominance is a fundamental concept in molecular genetics and has implications for understanding patterns of genetic variation, evolution, and complex traits. However, despite its importance, the degree of dominance in natural populations is poorly quantified. Here, we leverage multiple mating systems in natural populations of Arabidopsis to co-estimate the distribution of fitness effects and dominance coefficients of new amino acid changing mutations. We find that more deleterious mutations are more likely to be recessive than less deleterious mutations. Further, this pattern holds across gene categories, but varies with the connectivity and expression patterns of genes. Our work argues that dominance arises as a consequence of the functional importance of genes and their optimal expression levels
Toxicity of ZnO and TiO<font size=-1><sub>2</sub></font> to Escherichia coli cells
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Eye movements and reading in glaucoma: observations on patients with advanced visual field loss
Purpose To investigate the relationship between reading speed and eye movements in patients with advanced glaucomatous visual field (VF) defects and age-similar visually healthy people. Methods Eighteen patients with advanced bilateral VF defects (mean age: 71, standard deviation [SD]: 7 years) and 39
controls (mean age: 67, SD: 8 years) had reading speed measured using short passages of text on a computer set-up incorporating eye tracking. Scanpaths were plotted and analysed from these experiments to derive measures of ‘perceptual span’ (total number of letters read per number of saccades) and ‘text saturation’ (the distance between the first and last fixation on lines of text). Another eye movement measure, termed ‘saccadic frequency’ (total number of saccades made to read a single word), was derived from a separate lexical decision task, where words were presented in isolation. Results Significant linear association was demonstrated between perceptual span and reading speed in patients (R2=0.42) and controls (R2=0.56). Linear association between saccadic frequency during the LDT and reading speed was also found in patients (R2=0.42), but not in controls (R2=0.02). Patients also exhibited greater average text saturation than controls (P=0.004). Conclusion Some, but not all, patients with advanced VF defects read slower than controls using short text passages. Differences in eye movement behaviour may partly account for this variability in patients. These patients were shown to saturate lines of text more during reading, which may explain previously-reported difficulties with sustained reading
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