Procedural Outcomes of Double Vs. Single Fluoroscopy for Fixing Supracondylar Humerus Fractures in Children: A Case-Control Study

Background: Supracondylar humerus fractures (SHFs) are frequently seen in the pediatric population. The aim of this study was to compare single- and double-fluoroscopy methods for the closed reduction and percutaneous pinning (CRPP) of Gartland type 2 and type 3 SHFs. Materials and Methods: Forty patients who underwent surgery between March 2016 and April 2018 were evaluated retrospectively. Twenty-one patients (group 1) who received double fluoroscopy and 19 patients (group 2) who had single fluoroscopy were evaluated. The preparation period, surgical duration, radiation exposure time, fracture types, sex distributions, distribution of sides, radiologic results at the third month, cosmetic and functional results, and the incidence of complications were recorded. Results: The mean age of the patients in group 1 and group 2 was 4.76 and 4.68 years, respectively. The mean preparation time of group 1 was 11.3 min; whereas in group 2, it was 8.7 min (p < 0.01). The mean surgical duration was 31.76 min in group 1, and 40.47 min in group 2 (p < 0.01). The mean radiation exposure time in group 1 and group 2 was 41.19 and 47.36 s, respectively (p = 0.04). There were statistically significant differences between the two groups in terms of the preparation period, surgical duration, and radiation exposure time. Radiation exposure time and surgical duration were significantly shorter in group 1; the preparation period was shorter in group 2. Conclusions: The double-fluoroscopy technique can significantly reduce surgical duration and radiation exposure time during surgery while treating SHFs of children. © 2020, Indian Orthopaedics Association

Two-photon microscopy-guided femtosecond-laser photoablation of avian cardiogenesis: Noninvasive creation of localized heart defects

Yalçın, Hüseyin Çağatay (Dogus Author)Embryonic heart formation is driven by complex feedback between genetic and hemodynamic stimuli. Clinical congenital heart defects (CHD), however, often manifest as localized microtissue malformations with no underlying genetic mutation, suggesting that altered hemodynamics during embryonic development may play a role. An investigation of this relationship has been impaired by a lack of experimental tools that can create locally targeted cardiac perturbations. Here we have developed noninvasive optical techniques that can modulate avian cardiogenesis to dissect relationships between alterations in mechanical signaling and CHD. We used two-photon excited fluorescence microscopy to monitor cushion and ventricular dynamics and femtosecond pulsed laser photoablation to target micrometer-sized volumes inside the beating chick hearts. We selectively photoablated a small (∼100 μm radius) region of the superior atrioventricular (AV) cushion in Hamburger-Hamilton 24 chick embryos. We quantified via ultrasound that the disruption causes AV regurgitation, which resulted in a venous pooling of blood and severe arterial constriction. At 48 h postablation, quantitative X-ray microcomputed tomography imaging demonstrated stunted ventricular growth and pronounced left atrial dilation. A histological analysis demonstrated that the laser ablation produced defects localized to the superior AV cushion: a small quasispherical region of cushion tissue was completely obliterated, and the area adjacent to the myocardial wall was less cellularized. Both cushions and myocardium were significantly smaller than sham-operated controls. Our results highlight that two-photon excited fluorescence coupled with femtosecond pulsed laser photoablation should be considered a powerful tool for studying hemodynamic signaling in cardiac morphogenesis through the creation of localized microscale defects that may mimic clinical CHD

An ex-ovo chicken embryo culture system suitable for imaging and microsurgery applications

Yalçın, Hüseyin Çağatay (Dogus Author)Understanding the relationships between genetic and microenvironmental factors that drive normal and malformed embryonic development is fundamental for discovering new therapeutic strategies. Advancements in imaging technology have enabled quantitative investigation of the organization and maturing of the body plan, but later stage embryonic morphogenesis is less clear. Chicken embryos are an attractive vertebrate animal model system for this application because of its ease of culture and surgical manipulation. Early embryos can be cultured for a short time on filter paper rings, which enables complete optical access for cell patterning and fate studies. Studying advanced developmental processes such as cardiac morphogenesis are traditionally performed through a window of the eggshell, but this technique limits optical access due to window size. We previously developed a simple method to culture whole embryos ex-ovo on hexagonal weigh boats for up to 10 days, which enabled high resolution imaging via ultrasonography. These cultures were difficult to transport, limiting the types of imaging tools available for live experiments. We here present an improved shell-less culture system with a cost-effective, portable environmental chamber. Eggs were cracked onto a hammock created by a polyurethane membrane (cling wrap) affixed circumferentially to a plastic cup partially filled with sterile water. The dimensions of the circumference and depth of the hammock were both critical to maintain surface tension, while the mechanics of the hammock and water beneath helped dampen vibrations induced by transportation. A small footprint circulating water bath was also developed to enable continuous temperature control during experimentation. We demonstrate the ability to culture embryos in this way for at least 14 days without morphogenic defect or delay and employ this system in several microsurgical and imaging applications

Gas seepage and seismogenic structures along the North Anatolian Fault in the eastern Sea of Marmara

We carried out a combined geophysical and gas-geochemical survey on an active fault strand along the North Anatolian Fault (NAF) system in the Gulf of İzmit (eastern Sea of Marmara), providing for the first time in this area data on the distribution of methane (CH4) and other gases dissolved in the bottom seawater, as well as the CH4isotopic composition. Based on high-resolution morphobathymetric data and chirp-sonar seismic reflection profiles we selected three areas with different tectonic features associated to the NAF system, where we performed visual and instrumental seafloor inspections, including in situ measurements of dissolved CH4, and sampling of the bottom water. Starting from background values of 2–10 nM, methane concentration in the bottom seawater increases abruptly up to 20 nM over the main NAF trace. CH4 concentration peaks up to ∼120 nM were detected above mounds related probably to gas and fluids expulsion. Methane is microbial (δ13CCH4: −67.3 and −76‰ versus VPDB), and was found mainly associated with pre-Holocene deposits topped by a 10–20 m thick draping of marine mud. The correlation between tectonic structures and gas-seepages at the seafloor suggests that the NAF in the Gulf of İzmit could represent a key site for long-term combined monitoring of fluid exhalations and seismicity to assess their potential as earthquake precursors

The transition between stochastic and deterministic behavior in an excitable gene circuit

We explore the connection between a stochastic simulation model and an ordinary differential equations (ODEs) model of the dynamics of an excitable gene circuit that exhibits noise-induced oscillations. Near a bifurcation point in the ODE model, the stochastic simulation model yields behavior dramatically different from that predicted by the ODE model. We analyze how that behavior depends on the gene copy number and find very slow convergence to the large number limit near the bifurcation point. The implications for understanding the dynamics of gene circuits and other birth-death dynamical systems with small numbers of constituents are discussed.Comment: PLoS ONE: Research Article, published 11 Apr 201

The environmental setting of Epipalaeolithic aggregation site Kharaneh IV

The archaeological site of Kharaneh IV in Jordan's Azraq Basin, and its relatively near neighbour Jilat 6 show evidence of sustained occupation of substantial size through the Early to Middle Epipalaeolithic (c. 24,000 - 15,000 cal BP). Here we review the geomorphological evidence for the environmental setting in which Kharaneh IV was established. The on-site stratigraphy is clearly differentiated from surrounding sediments, marked visually as well as by higher magnetic susceptibility values. Dating and analysis of off-site sediments show that a significant wetland existed at the site prior to and during early site occupation (~ 23,000 - 19,000 BP). This may explain why such a substantial site existed at this location. This wetland dating to the Last Glacial Maximum also provides important information on the palaeoenvironments and potential palaeoclimatic scenarios for today's eastern Jordanian desert, from where such evidence is scarce

Gas and seismicity within the Istanbul seismic gap

Understanding micro-seismicity is a critical question for earthquake hazard assessment. Since the devastating earthquakes of Izmit and Duzce in 1999, the seismicity along the submerged section of North Anatolian Fault within the Sea of Marmara (comprising the “Istanbul seismic gap”) has been extensively studied in order to infer its mechanical behaviour (creeping vs locked). So far, the seismicity has been interpreted only in terms of being tectonic-driven, although the Main Marmara Fault (MMF) is known to strike across multiple hydrocarbon gas sources. Here, we show that a large number of the aftershocks that followed the M 5.1 earthquake of July, 25th 2011 in the western Sea of Marmara, occurred within a zone of gas overpressuring in the 1.5–5 km depth range, from where pressurized gas is expected to migrate along the MMF, up to the surface sediment layers. Hence, gas-related processes should also be considered for a complete interpretation of the micro-seismicity (~M < 3) within the Istanbul offshore domain

Immersive Insights: A Hybrid Analytics System for Collaborative Exploratory Data Analysis

In the past few years, augmented reality (AR) and virtual reality (VR) technologies have experienced terrific improvements in both accessibility and hardware capabilities, encouraging the application of these devices across various domains. While researchers have demonstrated the possible advantages of AR and VR for certain data science tasks, it is still unclear how these technologies would perform in the context of exploratory data analysis (EDA) at large. In particular, we believe it is important to better understand which level of immersion EDA would concretely benefit from, and to quantify the contribution of AR and VR with respect to standard analysis workflows. In this work, we leverage a Dataspace reconfigurable hybrid reality environment to study how data scientists might perform EDA in a co-located, collaborative context. Specifically, we propose the design and implementation of Immersive Insights, a hybrid analytics system combining high-resolution displays, table projections, and augmented reality (AR) visualizations of the data. We conducted a two-part user study with twelve data scientists, in which we evaluated how different levels of data immersion affect the EDA process and compared the performance of Immersive Insights with a state-of-the-art, non-immersive data analysis system.Comment: VRST 201

Impact of SARS-CoV-2 ORF6 and its variant polymorphisms on host responses and viral pathogenesis

: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) encodes several proteins that inhibit host interferon responses. Among these, ORF6 antagonizes interferon signaling by disrupting nucleocytoplasmic trafficking through interactions with the nuclear pore complex components Nup98-Rae1. However, the roles and contributions of ORF6 during physiological infection remain unexplored. We assessed the role of ORF6 during infection using recombinant viruses carrying a deletion or loss-of-function (LoF) mutation in ORF6. ORF6 plays key roles in interferon antagonism and viral pathogenesis by interfering with nuclear import and specifically the translocation of IRF and STAT transcription factors. Additionally, ORF6 inhibits cellular mRNA export, resulting in the remodeling of the host cell proteome, and regulates viral protein expression. Interestingly, the ORF6:D61L mutation that emerged in the Omicron BA.2 and BA.4 variants exhibits reduced interactions with Nup98-Rae1 and consequently impairs immune evasion. Our findings highlight the role of ORF6 in antagonizing innate immunity and emphasize the importance of studying the immune evasion strategies of SARS-CoV-2