266 research outputs found

    Shock

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    This chapter targets to provide information to medical students, residents, and nurses on emergency medicine. The concept and definitions of shock have been mentioned. An overview about shock has been given at the beginning of the chapter. Different categories of shock have been elaborated with comparison. Each type of shock has been discussed with its specificities and its management. Septic shock has been extensively discussed and different definitions and terminology have been used. Latest surviving sepsis campaign guidelines have been scribbled down. Hemorrhagic shock has been widely discussed too and a table provided for the differentiation of stages of hemorrhagic shock. Finally, the chapter is concluded with all the references used for accomplishing this chapter

    Investigations of the structural dynamics of the water and proton channels in Photosystem II

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    Bei der lichtinduzierten Oxidation von Wasser im Photosystem II (PSII) werden zwei wassermolekĂŒle im katalytischen Zyklus des Metallclusters (Mn4CaO5) benötigt, und vier Protonen aus dem Cluster in den Lumen abgegeben. Daher ist es fĂŒr das VerstĂ€ndnis des MechanismusÂŽ der Wasseroxidation von entscheidender Bedeutung, die VerĂ€nderung der ProtonierungszustĂ€nde am cluster wĂ€hrend der Katalyse zu untersuchen. Hierbei sollten sowohl die WasserkanĂ€le fĂŒr die ZufĂŒhrung der SubstratwassermolekĂŒle als auch die Transportwege fĂŒr die Freisetzung der Protonen untersucht werden. Deshalb wurde in meiner ersten Veröffentlichung ein neues Protokoll entwickelt, um einzelne große Kristalle von dPSII mit einer LĂ€nge von ~3 mm in der LĂ€ngsachse zu zĂŒchten. Diese Kristalle mit einer Auflösung von ca. 8 Å gemessen. Um eine höhere Auflösung zu erzielen, ist die Verbesserung der KristallqualitĂ€t essenziell. Daher wurde in meiner zweiten Veröffentlichung die Struktur des Detergens-Protein-Komplexes von dPSII mit ÎČDM, durch Anwendung von SANS in Kombination mit SAXS untersucht. Die Ergebnisse zeigten, dass ÎČDM eine monomolekulare Schicht um dPSII bildet. DarĂŒber hinaus konnten freie Mizellen von ÎČDM in der Lösung nachgewiesen werden. Damit ist eine weitere Optimierung der ÎČDM-Konzentration in der Proteinlösung erforderlich, um die Bildung von freien Mizellen zu minimieren. In meiner dritten Veröffentlichung wurde die strukturelle Dynamik in den WasserkanĂ€len, wĂ€hrend des S2-S3 Übergangs mit Hilfe der XFEL untersucht. Ein Datensatz mit einer hohen Auflösung von 1,89 Å wurde durch die ZusammenfĂŒhrung von Daten gewonnen, die wĂ€hrend des S2-S3 Übergangs gesammelt wurden. In Anbetracht der Analyse der zusammengefĂŒhrten Daten und der einzelnen Zeitpunkte, die wĂ€hrend des S2-S3 Übergangs gesammelt wurden, ist es wahrscheinlich, dass ein Substratwasser durch den O1-Kanal geliefert wird. Im Gegensatz dazu wird ein Proton aus dem Cluster durch den Cl1 Transportweg in Richtung Lumen freigesetzt.The light-induced oxidation of water in Photosystem II (PSII) requires incorporating two water molecules in the catalytic cycle of the active metal cluster (Mn4CaO5). Furthermore, four protons are released towards the bulk from the cluster. Therefore, tracking the change of protonation states at the active catalytic site and the surrounding protein side chains during catalysis and elucidating the pathways of water substrate insertion and proton release are crucial to understanding the water oxidation mechanism. Therefore, in the first study of my work, a new protocol was developed to grow single large dPSIIcc crystals with a length of ~3 mm in the long axis. These crystals, soaked in D2O containing buffer, diffracted to about 8 Å resolution. Improving the crystal quality is crucial for achieving a better resolution. Consequently, in the second study of my work, the structure of the detergent-protein complex of ÎČDM-dPSIIcc has been investigated by applying SANS in combination with SAXS. The results showed that ÎČDM is forming a monomolecular layer around the dimeric PSII core complex (dPSIIcc). Moreover, the SAXS data detected a peak assigned to the free micelles of ÎČDM. These results raise the necessity to optimize the ÎČDM concentration in the protein solution to avoid the possible excess of free micelles. In the third study of my work, the structural dynamics in the water channels connecting the cluster to the lumen during the S2 S3 transition were investigated using serial femtosecond XFEL. A high-resolution data set was obtained at a resolution of 1.89 Å by combining data collected at RT. Considering the analysis of the combined data and the individual time points collected during the S2 S3 transition, it is likely that the substrate water insertion into the open coordination site of the Mn1 ion is delivered through the O1 channel. In contrast, a proton from the cluster is released towards the bulk through the Cl1 A channel

    Investigating School Uniform Design of Adolescent Girls in Saudi Arabia

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    The purpose of this research was to apply a functional, aesthetic, expressive consumer needs (FEA) model to designing and evaluating school uniforms that balance these three FEA consideration within the needs of adolescent girls in Saudi Arabia. Vitamin D deficiency is very common among adolescents in Saudi Arabia. Sunlight helps skin to produce Vitamin D. A total of 210 Saudi Arabian mothers responded to an online FEA needs survey regarding their daughter\u27s school uniform needs relative to the newly adopted Current Style Uniform and the proposed Design Styles A and B. Quantitative survey questions on a 7-point Likert scale were combined with several open-ended questions designed to obtain critique of the three types of uniforms. Results showed strong demand for modifying uniform designs to incorporate tan-through fabric could contribute to mediating this health concern

    Fiber optics based schemes modeling and simulation of QoS for Wi-Fi scenarios using OPNET modeler

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    Wireless Fidelity (Wi-Fi) network is created on the IEEE 802.11 standard. Connections for local devices in homes and business arenas are provided by Wi-Fi units. With the growing demand as well as penetration of wireless services, the wireless networks users now assume Quality of Service (QoS) besides performances comparable to what is accessible from secure networks. In this paper, OPNET Modeler is used as module and for the simulation of a fiber optic-based Wi-Fi network within a fixed local area network. The aim of this paper is to evaluate their Quality of service (QoS) performances in terms of Wi-Fi voice-packet delay and End-to-End for both Wi-Fi base fiber and Wi-Fi base line. Many scenarios, with same Physical and MAC parameters, have many subnet networks are implementing with fiber optics baseline in addition to Wi-Fi baseline, were created in the network OPNET simulation tool for obtaining the results. The results of simulation reveal that base line demonstrated more delay than base fiber

    Implementation of Digital Image processing in Calculating Normal Approach for Spherical Indenter Considering Elastic/Plastic Contact

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    In this work a study and calculation of the normal approach between two bodies, spherical and rough flat surface, had been conducted by the aid of image processing technique. Four kinds of metals of different work hardening index had been used as a surface specimens and by capturing images of resolution of 0.006565 mm/pixel a good estimate of the normal approach may be obtained the compression tests had been done in strength of material laboratory in mechanical engineering department, a Monsanto tensometer had been used to conduct the indentation tests. A light section measuring equipment microscope BK 70x50 was used to calculate the surface parameters of the texture profile like standard deviation of asperity peak heights, centre line average, asperity density and the radius of asperities. A Gaussian distribution of asperity peak height was assumed in calculating the theoretical value of the normal approach in the elastic and plastic regions and where compared with those obtained experimentally to verify the obtained results

    Are meta-paths necessary?: revisiting heterogeneous graph embeddings

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    The graph embedding paradigm projects nodes of a graph into a vector space, which can facilitate various downstream graph analysis tasks such as node classification and clustering. To efficiently learn node embeddings from a graph, graph embedding techniques usually preserve the proximity between node pairs sampled from the graph using random walks. In the context of a heterogeneous graph, which contains nodes from different domains, classical random walks are biased towards highly visible domains where nodes are associated with a dominant number of paths. To overcome this bias, existing heterogeneous graph embedding techniques typically rely on meta-paths (i.e., fixed sequences of node types) to guide random walks. However, using these meta-paths either requires prior knowledge from domain experts for optimal meta-path selection, or requires extended computations to combine all meta- paths shorter than a predefined length. In this paper, we propose an alternative solution that does not involve any meta-path. Specifically, we propose JUST, a heterogeneous graph embedding technique using random walks with JUmp and STay strategies to overcome the aforementioned bias in an more efficient manner. JUST can not only gracefully balance between homogeneous and heterogeneous edges, it can also balance the node distribution over different domains (i.e., node types). By conducting a thorough empirical evaluation of our method on three heterogeneous graph datasets, we show the superiority of our proposed technique. In particular, compared to a state-of-the-art heterogeneous graph embedding technique Hin2vec, which tries to optimally combine all meta-paths shorter than a predefined length, our technique yields better results in most experiments, with a dramatically reduced embedding learning time (about 3x speedup)

    Structural insights into the light-driven auto-assembly process of the water- oxidizing Mn4CaO5-cluster in photosystem II

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    In plants, algae and cyanobacteria, Photosystem II (PSII) catalyzes the light- driven splitting of water at a protein-bound Mn4CaO5-cluster, the water- oxidizing complex (WOC). In the photosynthetic organisms, the light-driven formation of the WOC from dissolved metal ions is a key process because it is essential in both initial activation and continuous repair of PSII. Structural information is required for understanding of this chaperone-free metal-cluster assembly. For the first time, we obtained a structure of PSII from Thermosynechococcus elongatus without the Mn4CaO5-cluster. Surprisingly, cluster-removal leaves the positions of all coordinating amino acid residues and most nearby water molecules largely unaffected, resulting in a pre- organized ligand shell for kinetically competent and error-free photo-assembly of the Mn4CaO5-cluster. First experiments initiating (i) partial disassembly and (ii) partial re-assembly after complete depletion of the Mn4CaO5-cluster agree with a specific bi-manganese cluster, likely a di-”-oxo bridged pair of Mn(III) ions, as an assembly intermediate

    Knowledge, Attitude, and Practice Regarding Coronavirus Disease-19: Population-Based Study in Iraq

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    INTRODUCTION: In March 2020, the world health organization declared Coronavirus Disease (COVID)-19 a pandemic global communicable disease, there is neither a vaccine nor a treatment for this virus. The aim of the current study was to assess knowledge, attitude, and practice (KAP) of Iraqi population toward COVID-19. METHODS: A cross-sectional study was conducted among 272 respondents from different states of Iraq using online administered questionnaires. The questions were adopted from the previous study and consist of three parts mainly socio-demographic, KAP. RESULTS: The majority of the respondents had good knowledge regarding COVID-19 (95.2%). A total of 97.8% of the respondents knew that COVID-19 caused by a virus. Regarding incubation period, 75% of them answer correctly that it is 2–15 days. Higher percept (39%) and 37.9% of participant people considered the disease as a very dangerous and seriously dangerous disease, respectively. The majority (85.3%) of the sample thought that no vaccination available for the disease. More than two-thirds of the sample (76.5%) were wearing face mask sometimes while only 19.5% wearing it all the time. The majority (265) out of 272 was ready to stay home if it required to prevent the spread of the disease. There was a significant association between gender, living state, and COVID-19 knowledge (p = 0.009, <0.0001), respectively. CONCLUSION: The overall knowledge, practice of respondents was good regarding COVID-19. People need to stay at home to prevent the infection and reduce the number of cases

    Synthesis and Spectral Characterization of Some New Substituted Bis-spirocyclohexanones Derived from Acetone

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    Diarylidene acetones (DAA) (1-5) had been prepared by the condensation of acetone with substituted benzaldehydes via Claisen-Schmidt reaction, DAA’s brought to condense with anthrone to afford the title compounds (6-10) through Michael addition. The structures of the products were suggested in the light of spectral data (UV, IR, 1H&13C-NMR)
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