374 research outputs found
Models of Star-Planet Magnetic Interaction
Magnetic interactions between a planet and its environment are known to lead
to phenomena such as aurorae and shocks in the solar system. The large number
of close-in exoplanets that were discovered triggered a renewed interest in
magnetic interactions in star-planet systems. Multiple other magnetic effects
were then unveiled, such as planet inflation or heating, planet migration,
planetary material escape, and even modification of the host star properties.
We review here the recent efforts in modelling and understanding magnetic
interactions between stars and planets in the context of compact systems. We
first provide simple estimates of the effects of magnetic interactions and then
detail analytical and numerical models for different representative scenarii.
We finally lay out a series of future developments that are needed today to
better understand and constrain these fascinating interactions.Comment: 23 pages, 10 figures, accepted as a chapter in the Handbook of
Exoplanet
Effectiveness of mouthwashes to reduce the SARS-COV-2 load in saliva of adults with diagnosis of COVID-19: systematic review and meta-analysis
COVID-19 still represents a threat to public health. In this sense, antiseptic mouthwashes have been suggested to reduce cross-contamination and community transmission.This systematic review and meta-analysis aimed to synthesize the evidence on the effectiveness of povidone-iodine (PVP-I), cetylpyridinium chloride (CPC) and chlorhexidine (CHX) mouthwashes in reducing SARS-COV-2 viral load in the saliva of adults diagnosed with COVID-19. After the systematic search in five electronic databases, 16 clinical trials published until June 2023 were analyzed. Of these, 6 were included in the meta-analysis.The standardized mean difference (SMD) was reported with its corresponding 95% confidence intervals (95%CI). An overall SMD of 0.51 (95%CI: -0.29 to 1.32; I² = 46.0%; p = 0.047) was found. For CPC, the combined effect found in the studies was not significant (SMD = -0.07; 95%CI: -0.42 to 0.28; I² = 0.0%; p = 0.373); the same occurred for CHX (SMD = 0.50; 95%CI: -43.32 to 44.32; I² = 0.0%; p = 1.000). However, PVP-I showed a more consistent profile with a significant combined effect (SMD = 4.15; 95%CI: 2.11 to 6.18) and negligible heterogeneity (I² = 0.0%; p = 0.908).The findings indicate a non-significant effect of mouthwashes on reducing viral load when all types were evaluated together. Separately, only PVP-I showed a significant reduction in viral load with a low level of certainty of evidence, while for CPC and CHX the reduction was not significant, with a low and very low level of certainty of evidence, respectively
Operating organic light-emitting diodes imaged by super-resolution spectroscopy
Super-resolution stimulated emission depletion (STED) microscopy is adapted here for materials characterization that would not otherwise be possible. With the example of organic light-emitting diodes (OLEDs), spectral imaging with pixel-by-pixel wavelength discrimination allows us to resolve local-chain environment encoded in the spectral response of the semi-conducting polymer, and correlate chain packing with local electroluminescence by using externally applied current as the excitation source. We observe nanoscopic defects that would be unresolvable by traditional microscopy. They are revealed in electroluminescence maps in operating OLEDs with 50 nm spatial resolution. We find that brightest emission comes from regions with more densely packed chains. Conventional microscopy of an operating OLED would lack the resolution needed to discriminate these features, while traditional methods to resolve nanoscale features generally cannot be performed when the device is operating. This points the way towards real-time analysis of materials design principles in devices as they actually operateope
Heavy and light roles: myosin in the morphogenesis of the heart
Myosin is an essential component of cardiac muscle, from the onset of cardiogenesis through to the adult heart. Although traditionally known for its role in energy transduction and force development, recent studies
suggest that both myosin heavy-chain and myosin lightchain
proteins are required for a correctly formed heart.
Myosins are structural proteins that are not only expressed
from early stages of heart development, but when mutated
in humans they may give rise to congenital heart defects.
This review will discuss the roles of myosin, specifically
with regards to the developing heart. The expression of
each myosin protein will be described, and the effects that
altering expression has on the heart in embryogenesis in
different animal models will be discussed. The human
molecular genetics of the myosins will also be reviewed
Is periodontitis a risk factor for ischemic stroke?: systematic review and meta-analysis
Evidence suggests an association between periodontitis and ischemic stroke due to the elevated production of inflammatory markers and damage by infectious agents, which would promote a recurrent prothrombotic state. Therefore, the present systematic review and meta-analysis were carried out to determine whether periodontitis is a risk factor for ischemic stroke.A systematic search was conducted in five databases, including cohort and case-control studies published up to April 2024, in which periodontitis was evaluated as a risk factor for ischemic stroke through relative risk (RR), hazard ratio (HR) and odds ratio (OR). The Newcastle-Ottawa Scale (NOS) was used to assess the risk of bias, and the GRADE system was used to determine the certainty of the evidence.Of the 1121 studies found, 16 were included in the qualitative analysis, and 10 were meta-analyzed. The global synthesis showed that periodontitis was a risk factor for ischemic stroke (OR=2.59, I2=96%), with the same result being found for the case-control subgroup (OR=3.44, I²=73%) and the cohort subgroup (OR=2.05, I²=99%). Individuals with periodontitis were also found to be more likely to develop lacunar infarcts (OR=5.00, I2=0%).Periodontitis is a risk factor for ischemic stroke with very low certainty of evidence and high heterogeneity. Furthermore, individuals with periodontitis were more likely to develop lacunar infarcts, with moderate certainty of evidence and null heterogeneity
Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.
BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112
Impact of well configuration on performance of steam-based gravity drainage processes in naturally fractured reservoirs
Mitochondrial Damage in the Trabecular Meshwork Occurs Only in Primary Open-Angle Glaucoma and in Pseudoexfoliative Glaucoma
Open-angle glaucoma appears to be induced by the malfunction of the trabecular meshwork cells due to injury induced by oxidative damage and mitochondrial impairment. Here, we report that, in fact, we have detected mitochondrial damage only in primary open-angle glaucoma and pseudo-exfoliation glaucoma, among several glaucoma types compared.Mitochondrial damage was evaluated by analyzing the common mitochondrial DNA deletion by real-time PCR in trabecular meshwork specimens collected at surgery from glaucomatous patients and controls. Glaucomatous patients included 38 patients affected by various glaucoma types: primary open-angle, pigmented, juvenile, congenital, pseudoexfoliative, acute, neovascular, and chronic closed-angle glaucoma. As control samples, we used 16 specimens collected from glaucoma-free corneal donors. Only primary open-angle glaucoma (3.0-fold) and pseudoexfoliative glaucoma (6.3-fold) showed significant increases in the amount of mitochondrial DNA deletion. In all other cases, deletion was similar to controls.despite the fact that the trabecular meshwork is the most important tissue in the physiopathology of aqueous humor outflow in all glaucoma types, the present study provides new information regarding basic physiopathology of this tissue: only in primary open-angle and pseudoexfoliative glaucomas oxidative damage arising from mitochondrial failure play a role in the functional decay of trabecular meshwork
Trabecular Meshwork Gene Expression after Selective Laser Trabeculoplasty
BACKGROUND: Trabecular meshwork and Schlemm's canal are the tissues appointed to modulate the aqueous humour outflow from the anterior chamber. The impairment of their functions drives to an intraocular pressure increase. The selective laser trabeculoplasty is a laser therapy of the trabecular meshwork able to decrease intraocular pressure. The exact response mechanism to this treatment has not been clearly delineated yet. The herein presented study is aimed at studying the gene expression changes induced in trabecular meshwork cells by selective laser trabeculoplasty (SLT) in order to better understand the mechanisms subtending its efficacy. METHODOLOGY/PRINCIPAL FINDINGS: Primary human trabecular meshwork cells cultured in fibroblast medium underwent selective laser trabeculoplasty treatment. RNA was extracted from a pool of cells 30 minutes after treatment while the remaining cells were further cultured and RNA was extracted respectively 2 and 6 hours after treatment. Control cells stored in incubator in absence of SLT treatment were used as reference samples. Gene expression was evaluated by hybridization on miRNA-microarray and laser scanner analysis. Scanning electron microscopic examination was performed on 2 Trabecular meshwork samples after SLT at 4(th) and 6(th) hour from treatment. On the whole, selective laser trabeculoplasty modulates in trabecular meshwork the expression of genes involved in cell motility, intercellular connections, extracellular matrix production, protein repair, DNA repair, membrane repair, reactive oxygen species production, glutamate toxicity, antioxidant activities, and inflammation. CONCLUSIONS/SIGNIFICANCE: SLT did not induce any phenotypic alteration in TM samples. TM is a complex tissue possessing a great variety of function pivotal for the active regulation of aqueous humour outflow from the anterior chamber. SLT is able to modulate these functions at the postgenomic molecular level without inducing damage either at molecular or phenotypic levels
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