Introduction: The shock index (SI), modified shock index (MSI), and age multiplied by SI (ASI) are used to assess the severity of shock. They are also used to predict the mortality of trauma ...patients, but their validity for sepsis patients is controversial. The aim of this study is to assess the predictive value of the SI, MSI, and ASI in predicting the need for mechanical ventilation after 24 h of admission among sepsis patients. Methods: A prospective observational study was conducted in a tertiary care teaching hospital. Patients with sepsis (235) diagnosed based on systemic inflammatory response syndrome criteria and quick sequential organ failure assessment were included in the study. The need for mechanical ventilation after 24 h is the outcome variables MSI, SI, and ASI were considered as predictor variables. The utility of MSI, SI, and ASI in predicting mechanical ventilation was assessed by receiver operative curve analysis. Data were analyzed using coGuide. Results: Among the study population, the mean age was 56.12 ± 17.28 years. MSI value at the time of disposition from the emergency room had good predictive validity in predicting mechanical ventilation after 24 h, as indicated by the area under the curve (AUC) of 0.81 (P < 0.001), SI and ASI had fair predictive validity for mechanical ventilation as indicated by AUC (0.78, P < 0.001) and (0.802, P < 0.001), respectively. Conclusion: SI had better sensitivity (78.57%) and specificity (77.07%) compared to ASI and MSI in predicting the need for mechanical ventilation after 24 h in sepsis patients admitted to intensive care units.
ABSTRACT
The Indian Ocean region is one among the six major cyclone prone regions in the world with an annual average of about five to six cyclones. Prior studies conducted for this region are ...location‐specific and confined to storm surge characteristic and associated inundation. A detailed study to develop precomputed scenarios on storm surge and inundation maps for the entire Indian coast is still lacking for emergency preparedness. An effort in this direction can drastically reduce preparedness time in the eventuality of a real cyclone approaching its landfall location for effective coastal zone management measures. The present study is a motivation in this direction leading to the generation of a comprehensive data set on storm surges and associated coastal flooding for entire Odisha coast located in the east coast of India and that can be extended to other coastal regions as well. Historically, the Odisha State experiences highest number of cyclone strikes with the highest risk of exposure to storm surge and inundation. The novelty of this study is in the preparation of a comprehensive storm data set using synthetic tracks simulated with various combinations of landfall location, angle of attack, intensity, and forward translation speed. It also generates possible storm surge and inundation associated with intensified cyclones expected in a changing climate scenario. Further, the study also correlates power dissipation index with storm tide all along this coast. The distribution of surge height follows a third‐order polynomial to wind speed. An in‐depth analysis was also carried out to understand the characteristics of storm surge height and extent of coastal inundation with respect to coastal geomorphology, angle of attack, and varying forward speed of cyclones. The authors believe that information and analysis from this comprehensive data set will have immense potential in understanding the impacts from tropical cyclone climatology and disaster management applications.
Yearly frequency of (a) cyclones and depressions, (b) very severe cyclonic storms in the north Indian Ocean, (c) depressions, cyclones and severe cyclonic storms and (d) severe cyclonic storms in the Bay of Bengal.
In this article we present a class of relativistic solutions describing spherically symmetric and static anisotropic stars in hydrostatic equilibrium. For this purpose, we consider a particularized ...metric potential, namely, Buchdahl ansatz Phys. Rev. D 116, 1027 (1959). which encompasses almost all the known analytic solutions to the spherically symmetric, static Einstein equations with a perfect fluid source, including, in particular, the Vaidya-Tikekar and Finch-Skea. We developed the model by considering an anisotropic spherically symmetric static general relativistic configuration that has a significant effect on the structure and properties of stellar objects. We have considered eight different cases for generalized Buchdahl dimensionless parameter K and analyzed them in a uniform manner. As a result it turns out that all the considered cases are valid at every point in the interior spacetime. In addition to this, we show that the model satisfies all the energy conditions and maintains the hydrostatic equilibrium equation. In the frame work of anisotropic hypothesis, we consider analogue objects with similar mass and radii, such as LMC X-4, SMC X-1, EXO 1785-248 etc. to restrict the model parameter arbitrariness. Also, establishing a relation between pressure and density in the form of P=P(ρ), we demonstrate that equation of state (EoS) can be approximated to a linear function of density. Despite the simplicity of this model, the obtained results are satisfactory.
The mechanical response of single crystal silicon carbide (SiC) of two hexagonal polytypes (six layer, 6H- and four layer, 4H) was investigated using nanoindentation. Indentations were performed on ...two specific crystallographic orientations of single crystals i.e., normal to the basal, (0001) and prismatic, (101¯0) planes, in the load range between 25 mN and 500 mN. A significant anisotropy in the hardness is observed with the basal orientations showing a higher hardness compared to prismatic orientations. In both orientations, the 6H-SiC polytype exhibits higher hardness than the 4H-SiC polytype. It is also observed that the hardness decreases with increasing indentation load, suggesting that SiC crystals exhibit indentation size effect. However, unlike hardness, elastic modulus is independent of indentation load and the elastic anisotropy is insignificant. Severe cracking, particularly at higher indentation loads is noticed near the edges of the indentation imprints. The indentation fracture toughness, KICi computed from the imprints shows slightly higher values for 6H-SiC compared to the 4H-SiC. However, for both the polytypes, a slightly higher KICi is observed for basal indentations compared to the prismatic ones.
•4H- and 6H-SiC single crystal polytypes exhibit a strong indentation size effect.•Nanohardness of basal (0001) orientations is higher than the prismatic (101¯0) ones.•The indentation fracture toughness of (0001) orientations is higher than the (101¯0).•Hardness and indentation fracture toughness of 6H-SiC is higher than the 4H-SiC single crystals.
The mechanical properties of polyvinyl alcohol (PVA) and poly(methyl methacrylate) (PMMA)-matrix composites reinforced by functionalized few-layer graphene (FG) have been evaluated using the ...nano-indentation technique. A significant increase in both the elastic modulus and hardness is observed with the addition of 0.6 wt% of graphene. The crystallinity of PVA also increases with the addition of FG. This and the good mechanical interaction between the polymer and the FG, which provides better load transfer between the matrix and the fiber, are suggested to be responsible for the observed improvement in mechanical properties of the polymers.
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•PANI/PVA/GO and PANI/PVA nanofibers were prepared via electrospinning.•Specific capacitance of the nanofibers was calculated from Cyclic Voltammetry.•Nanofibrous morphology ...positively influences the specific capacitance value.•GO inclusion enhances the specific capacitance of PANI/PVA composite nanofibers.
High-performance energy-storage gadgets, including supercapacitors hold great capability for various applications, such as portable electronics, electric vehicles etc. Portable electronics industry necessitates the employment of energy storage devices with large energy and power densities. Supercapacitors require electrode materials having better morphology, surface area, and carrier mobility that provide high capacitance. In this work we concentrate on the synthesis and electrochemical characterization of a material suitable to be used as supercapacitor electrode. Graphene Oxide/Polyaniline/Polyvinyl alcohol nanofibers were obtained via electrospinning process. The crystalline structure and morphology of developed nanofibers have been illustrated using X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM). The electrochemical performance of the PANI-PVA-GO composite nanofibers was investigated as a supercapacitor electrode material through Cyclic Voltammetry (CV) studies. The nanofibers comprising Graphene Oxide exhibited better specific capacitance than polymer nanofibers thereby providing a novel way for fabrication of supercapacitor electrodes. This manuscript also gives a comparison of specific capacitance achieved by different compositions of Graphene Oxide, Polymers and transition metals reported in previous works.
Atmospheric and oceanic parameters derived from global climate model (GCM) simulations have received wide global attention and importance in representing the future world under different scenarios of ...greenhouse gas emissions. The present study deals with near-surface wind speed in the Bay of Bengal (BoB) obtained from CMIP5 and the upcoming CMIP6 GCMs and validation exercise clearly signify improved performance of CMIP6 GCMs over CMIP5. Multi-model ensemble mean corresponding to the four emission scenarios are constructed using the best performing models of CMIP6 family. The study reveals that near-future changes in wind speed in the BoB are moderate under the low-end scenario of SSP1-2.6. Projected wind speeds in the head BoB are expected to increase or decrease by 20% during June–July–August and December–January–February under high-end scenario by the end of twenty-first century. A positive change up to 30% in the northeast monsoon winds under SSP5-8.5 is projected in the central BoB. Irrespective of the seasons, a net increase amounting to 0.6–0.8 m/s is observed along the east coast of India under SSP2-4.5 scenario by the mid and end of the century. Maximum rise by 25% (0.5–1 m/s) in wind speed is predicted under SSP3-7.0 scenario in the near future. Further, the study points out a decline in wind speed by 0.2–0.8 m/s in the central and southern BoB under the extreme scenario of SSP5-8.5. Strengthening and weakening of winds over the BoB accounts the projected variations in temperature that resulted from global warming and subsequent changes in atmospheric circulation.
Rising sea levels pose a potential threat to the low‐lying regions for the countries that surround the Indo‐Pacific belt. Changes in sea level and its variability are intrinsically connected with sea ...surface temperature (SST) variations and associated wind field patterns in the Indo‐Pacific Ocean (IPO). SST‐based climate variability modes such as El Niño–Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), and Pacific Decadal Oscillation (PDO) tend to influence the sea level variability over the IPO significantly. The impact of climate variability modes on SLA, SST, and wind speed is examined by using regression analysis. The study considered two different datasets, namely the AVISO SLA and reconstructed SSHA from 1993 to 2019 and 1952 to 2009, respectively. SLA and SST both exhibit a decreasing trend from 1997 to 2007 year‐round; however, by the next decade (2008–2018), an overall increasing trend is evident in both parameters throughout the year. The influence of independent ENSO after removing the PDO signal (ENSO|PDO) on SLA and SST exhibits statistically significant increases over the eastern PO, western tropical IO, but decreases over the AS, eastern IO, and western PO during DJF. SLA response to IOD removing ENSO (IOD|ENSO) during SON includes increases over western to central tropical IO, and decreases over the AS extending up to eastern IO. Lastly, for the PDO influence in DJF, statistically significant increases in SLA are evident over the north PO extending up to eastern PO; however, PDO|ENSO influence over SLA exhibits similar but significantly reduced amplitudes. Composite analysis of different phase combinations of PDO (IOD) with El Niño (La Niña) exhibits stronger (weaker) influences during DJF (SON) season.
Deseasonalized, detrended, and normalized mean time series for (a) ENSO and ENSO|PDO during DJF, (b) ENSO, IOD, PDO and ENSO|IOD, PDO during SON, (c) IOD and IOD|ENSO during SON, (d) PDO and PDO|ENSO during DJF from 1952 to 2019. The dotted lines represent the lower and upper bound range −0.5 and 0.5 in °C, respectively.
Inspired by nature, it is envisaged that a nanorough surface exhibits bactericidal properties by rupturing bacterial cells. In order to study the interaction mechanism between the cell membrane of a ...bacteria and a nanospike at the contact point, a finite element model was developed using the ABAQUS software package. The model, which saw a quarter of a gram-negative bacteria (
) cell membrane adhered to a 3 × 6 array of nanospikes, was validated by the published results, which show a reasonably good agreement with the model. The stress and strain development in the cell membrane was modeled and were observed to be spatially linear and temporally nonlinear. From the study, it was observed that the bacterial cell wall was deformed around the location of the nanospike tips as full contact was generated. Around the contact point, the principal stress reached above the critical stress leading to a creep deformation that is expected to cause cell rupture by penetrating the nanospike, and the mechanism is envisaged to be somewhat similar to that of a paper punching machine. The obtained results in this project can provide an insight on how bacterial cells of a specific species are deformed when they adhere to nanospikes, and how it is ruptured using this mechanism.
Nanopatterned surfaces are believed to kill bacteria through physical deformation, a mechanism that has immense potential against biochemical resistance. Because of its elusive nature, this mechanism ...is mostly understood through biophysical modeling. Problematically, accurate descriptions of the contact mechanics and various boundary conditions involved in the bacteria-nanopattern interaction remain to be seen. This may underpin conflicting predictions, found throughout the literature, regarding two important aspects of the mechanism—that is, its critical action site and relationship with geometry. Herein, a robust computational analysis of bacteria-nanopattern interaction is performed using a three-dimensional finite element modeling that incorporates relevant continuum mechanical properties, multilayered envelope structure, and adhesion interaction conditions. The model is applied to more accurately study the elusory mechanism and its enhancement via nanopattern geometry. Additionally, micrographs of bacteria adhered on a nanopatterned cicada wing are examined to further inform and verify the major modeling predictions. Together, the results indicate that nanopatterned surfaces do not kill bacteria predominantly by rupture in between protruding pillars as previously thought. Instead, nondevelopable deformation about pillar tips is more likely to create a critical site at the pillar apex, which delivers significant in-plane strains and may locally rupture and penetrate the cell. The computational analysis also demonstrates that envelope deformation is increased by adhesion to nanopatterns with smaller pillar radii and spacing. These results further progress understanding of the mechanism of nanopatterned surfaces and help guide their design for enhanced bactericidal efficiency.
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