Precipitation variations in the tropical Indian Ocean region result from changes in the Indian Summer Monsoon (ISM), as well as convective and cyclonic rainfall. The relative roles of such forcing can be elucidated by constructing robust paleoclimate records, which help to better predict future variability in precipitation due to rising greenhouse gases. This study was carried out using a suite of paleoclimate proxies on a combination of marine and terrestrial sediment cores from Sri Lanka.
View Article and Find Full Text PDFThe ductility and exhibition of the multiple, fine, self-controlled cracking of strain-hardening cementitious composites (SHCCs) under tension has made them attractive for enhancing the durability of civil infrastructure. These fine cracks are key to preventing the ingress of water and harmful chemicals into the structure and thereby achieving steel reinforcement. However, several studies have suggested that the short-term fine cracks shown in the laboratory may end up exceeding the acceptable crack widths that are specified in design codes when SHCC members are subjected to sustained constant loads.
View Article and Find Full Text PDFBackground And Purpose: Hemorrhagic transformation (HT) has been reported in up to 50% of acute ischemic stroke (AIS) patients with a large vessel occlusion (LVO) treated with endovascular thrombectomy (EVT). HT may be driven by postrecanalization hyperperfusion injury and is independently associated with worse functional outcomes. Strategies to identify patients at risk for HT may assist in developing preventive therapies.
View Article and Find Full Text PDFPhosphatidylinositol (3,4,5) trisphosphate (PIP3) is a plasma membrane-bound signaling phospholipid involved in many cellular signaling pathways that control crucial cellular processes and behaviors, including cytoskeleton remodeling, metabolism, chemotaxis, and apoptosis. Therefore, defective PIP3 signaling is implicated in various diseases, including cancer, diabetes, obesity, and cardiovascular diseases. Upon activation by G protein-coupled receptors (GPCRs) or receptor tyrosine kinases (RTKs), phosphoinositide-3-kinases (PI3Ks) phosphorylate phosphatidylinositol (4,5) bisphosphate (PIP2), generating PIP3.
View Article and Find Full Text PDFCulture of care in Laboratory Animal Science (LAS) refers to a commitment toward improving animal welfare, scientific quality, staff wellbeing, and transparency for all stakeholders, ensuring that the animals and personnel involved are treated with compassion and respect. A strong culture of care can be established by the proactive implementation of the Three Rs, sharing best practices, caring for and respecting animals and colleagues, empowering staff, taking responsibility for our actions, and having a caring leadership. Culture of care, when established, should be evaluated continuously, in order to foster its progress and persistence.
View Article and Find Full Text PDFOptical coherence tomography (OCT) has become an important tool for measuring the vibratory response of the living cochlea. It stands alone in its capacity to measure the intricate motion of the hearing organ through the surrounding otic capsule bone. Nevertheless, as an extension of phase-sensitive OCT, it is only capable of measuring motion along the optical axis.
View Article and Find Full Text PDFWe describe an optical coherence tomography and vibrometry system designed for portable hand-held usage in the otology clinic on awake patients. The system provides clinically relevant point-of-care morphological imaging with 14-44 µm resolution and functional vibratory measures with sub-nanometer sensitivity. We evaluated various new approaches for extracting functional information including a multi-tone stimulus, a continuous chirp stimulus, and alternating air and bone stimulus.
View Article and Find Full Text PDFBackground And Objective: There exists no standardized curriculum for pediatric residents to develop procedural skills during residency training. Many pediatric residency programs are transitioning to block education sessions; the effectiveness of this format for delivering pediatric emergency medicine (PEM) procedural curriculum has not been evaluated. The objective is to determine if a PEM block education session improved pediatric residents' knowledge and confidence in 4 domains: laceration repair, splinting of extremities, resuscitation/airway management, and point-of-care ultrasound.
View Article and Find Full Text PDFG protein-coupled receptors (GPCRs) transmit information to the cell interior by transducing external signals to heterotrimeric G protein subunits, Gα and Gβγ subunits, localized on the inner leaflet of the plasma membrane. Though the initial focus was mainly on Gα-mediated events, Gβγ subunits were later identified as major contributors to GPCR-G protein signalling. A broad functional array of Gβγ signalling has recently been attributed to Gβ and Gγ subtype diversity, comprising 5 Gβ and 12 Gγ subtypes, respectively.
View Article and Find Full Text PDFMicrocystins are cyclic peptide toxins formed by cyanobacteria. These toxins are recognized for their association with algal blooms, posing a significant threat to ecosystems and drinking water quality. Due to the growing environmental concerns they raise, a comprehensive review on microcystins' genesis, toxicity, and analytical methods for their quantitative determination is outlined.
View Article and Find Full Text PDFThe chemical- and photo- toxicity of chromophore retinal on cells have long been debated. Although we recently showed that retinal and blue light exposure interrupt cellular signaling, a comprehensive study examining molecular underpinnings of this perturbation and its consequences to cellular fate is lacking. Here, we report molecular evidence for blue light excited-retinal induced oxidative damage of polyunsaturated lipid anchors in membrane-interacting signaling molecules and DNA damage in cells using live-cell imaging and in vitro experimentation.
View Article and Find Full Text PDFBackground: There is an increased emphasis on reducing exposure to ionizing radiation in pediatric patients. Guidelines from the Pediatric Emergency Care Applied Research Network help practitioners identify patients at low risk for clinically important traumatic brain injury after head injury.
Objectives: We seek to determine whether the institution of a pediatric track staffed by pediatric emergency medicine physicians (PEMs) within a community emergency department (ED) impacts the overall utilization of head computed tomography (CT) on children younger than 15 years with head injury.
G protein-coupled receptors (GPCRs), G proteins, and their signaling associates are major signal transducers that control the majority of cellular signaling and regulate key biological functions including immune, neurological, cardiovascular, and metabolic processes. These pathways are targeted by over one-third of drugs on the market; however, the current understanding of their function is limited and primarily derived from cell-destructive approaches providing an ensemble of static, multi-cell information about the status and composition of molecules. Spatiotemporal behavior of molecules involved is crucial to understanding in vivo cell behaviors both in health and disease, and the advent of genetically encoded fluorescence proteins and small fluorophore-based biosensors has facilitated the mapping of dynamic signaling in cells with subcellular acuity.
View Article and Find Full Text PDFPhotoreceptor chromophore, 11-cis retinal (11CR) and the photoproduct, all-trans retinal (ATR), are present in the retina at higher concentrations and interact with the visual cells. Non-visual cells in the body are also exposed to retinal that enters the circulation. Although the cornea and the lens of the eye are transparent to the blue light region where retinal can absorb and undergo excitation, the reported phototoxicity in the eye has been assigned to lipophilic non-degradable materials known as lipofuscins, which also includes retinal condensation products.
View Article and Find Full Text PDFBiochem Biophys Res Commun
September 2018
Interactions of cytosolic G protein coupled receptor kinase 2 (GRK2) with activated G protein coupled receptors (GPCRs) induce receptor phosphorylation and desensitization. GRK2 is recruited to active M3-muscarinic receptors (M3R) with the participation of the receptor, Gαq and Gβγ. Since we have shown that signaling efficacy of Gβγ is governed by its Gγ subtype identity, the present study examined whether recruitment of GRK2 to M3R is also Gγ subtype dependent.
View Article and Find Full Text PDFHeterotrimeric guanine nucleotide-binding proteins (G proteins) deliver external signals to the cell interior, upon activation by the external signal stimulated G protein-coupled receptors (GPCRs).While the activated GPCRs control several pathways independently, activated G proteins control the vast majority of cellular and physiological functions, ranging from vision to cardiovascular homeostasis. Activated GPCRs dissociate GαGDPβγ heterotrimer into GαGTP and free Gβγ.
View Article and Find Full Text PDFMelanopsin (Opn4), a ubiquitously expressed photoreceptor in all classes of vertebrates, is crucial for both visual and non-visual signaling. Opn4 supports visual functions of the eye by sensing radiance levels and discriminating contrast and brightness. Non-image-forming functions of Opn4 not only regulate circadian behavior, but also control growth and development processes of the retina.
View Article and Find Full Text PDFBackground In 2014, New Zealand reclassified sildenafil (for erectile dysfunction) to allow supply by specially trained pharmacists under strict criteria. Objective The study aimed to determine pharmacists' experiences and perspectives on the training for, and supply of sildenafil under this model. Setting New Zealand community pharmacy.
View Article and Find Full Text PDFG protein-coupled receptors (GPCRs) are the largest family of cell surface receptors in eukaryotic genomes. They control a variety of cellular and physiological processes such as hormone secretion and heart rate, and therefore are associated with a majority of pathological conditions including cancer and heart diseases. Currently established assays to measure ligand-induced activation of GPCRs and G proteins possess limitations such as being time consuming, indirect, and expensive.
View Article and Find Full Text PDFChemokine-induced directional cell migration is a universal cellular mechanism and plays crucial roles in numerous biological processes, including embryonic development, immune system function, and tissue remodeling and regeneration. During the migration of a stationary cell, the cell polarizes, forms lamellipodia at the leading edge (LE), and triggers the concurrent retraction of the trailing edge (TE). During cell migration governed by inhibitory G protein (G)-coupled receptors (GPCRs), G protein βγ (Gβγ) subunits control the LE signaling.
View Article and Find Full Text PDFThe ethylene/norbornene content within cyclic olefin copolymer (COC) is well known to affect the chemical and physical properties of the copolymer, such as the glass transition temperature (T) and transparency. However, no work has been reported evaluating the effects of the ethylene/norbornene content on the surface properties of COC following UV/O or O plasma activation. Activation with either O plasma or UV/O is often used to assist in thermal assembly of fluidic devices, increasing the wettability of the surfaces, or generating functional scaffolds for the attachment of biological elements.
View Article and Find Full Text PDFCurrent assays to measure the activation of G protein coupled receptors (GPCRs) and G proteins are time-consuming, indirect, and expensive. Therefore, an efficient method which directly measures the ability of a ligand to govern GPCR-G protein interactions can help to understand the molecular underpinnings of the associated signaling. A live cell imaging-based approach is presented here to directly measure ligand-induced GPCR and G protein activity in real time.
View Article and Find Full Text PDFMinor cervical spine injury is a common cause of pediatric emergency department visits. We present a case of a 10-year-old boy with transient paresthesia after minor cervical trauma found to have a rare cervical spine abnormality requiring surgical fusion. We present and discuss the management options for os odontoideum.
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