Orthopaedic and dental implants have become a staple of the medical industry and with an ageing population and growing culture for active lifestyles, this trend is forecast to continue. In accordance ...with the increased demand for implants, failure rates, particularly those caused by bacterial infection, need to be reduced. The past two decades have led to developments in antibiotics and antibacterial coatings to reduce revision surgery and death rates caused by infection. The limited effectiveness of these approaches has spurred research into nano-textured surfaces, designed to mimic the bactericidal properties of some animal, plant and insect species, and their topographical features. This review discusses the surface structures of cicada, dragonfly and butterfly wings, shark skin, gecko feet, taro and lotus leaves, emphasising the relationship between nano-structures and high surface contact angles on self-cleaning and bactericidal properties. Comparison of these surfaces shows large variations in structure dimension and configuration, indicating that there is no one particular surface structure that exhibits bactericidal behaviour against all types of microorganisms. Recent bio-mimicking fabrication methods are explored, finding hydrothermal synthesis to be the most commonly used technique, due to its environmentally friendly nature and relative simplicity compared to other methods. In addition, current proposed bactericidal mechanisms between bacteria cells and nano-textured surfaces are presented and discussed. These models could be improved by including additional parameters such as biological cell membrane properties, adhesion forces, bacteria dynamics and nano-structure mechanical properties. This paper lastly reviews the mechanical stability and cytotoxicity of micro and nano-structures and materials. While the future of nano-biomaterials is promising, long-term effects of micro and nano-structures in the body must be established before nano-textures can be used on orthopaedic implant surfaces as way of inhibiting bacterial adhesion.
We investigated the effects of the chirality of carbon nanotubes (CNTs) on water transport using molecular dynamics simulations. For the study, we considered CNTs with similar diameter and varying ...chiralities, obtained by altering the chiral indices (n,m) of the nanotubes. The tubes with an armchair (n = m) structure show the maximum streaming velocity, flux, flow rate enhancement and slip length, whereas the corresponding values are lower for chiral (n≠m) tubes, and are the lowest in zigzag (m = 0) CNTs. The difference in flow rates with varying tube structures can be primarily attributed to the alteration in potential energy landscape experienced by the water molecules, leading to changes in the friction coefficient at the fluid-solid interface. The water molecules experienced the least resistance to flow in an armchair tube, while the force exerted by the CNT surface on the water molecules increased monotonically with the change in the CNT type to chiral and then to zigzag. The chirality effects on water transport are, however, found to decrease with an increase in tube diameter. Furthermore, an analysis of the influence of the CNT type on ion (Na
or Cl
) transport in water-filled CNTs showed the interaction energy of ions with water to be much higher than that with the CNT surface, demonstrating minimal dependence of ion transport on the chiral structure. Hence, the tube chirality should be considered an ineludible factor in controlling the water transport through CNTs and in the designing of novel devices in nanotechnology.
Modest exciton diffusion lengths dictate the need for nanostructured bulk heterojunctions in organic photovoltaic (OPV) cells; however, this morphology compromises charge collection. Here, we reveal ...rapid exciton diffusion in films of a fused-ring electron acceptor that, when blended with a donor, already outperforms fullerene-based OPV cells. Temperature-dependent ultrafast exciton annihilation measurements are used to resolve a quasi-activationless exciton diffusion coefficient of at least 2 × 10–2 cm2/s, substantially exceeding typical organic semiconductors and consistent with the 20–50 nm domain sizes in optimized blends. Enhanced three-dimensional diffusion is shown to arise from molecular and packing factors; the rigid planar molecular structure is associated with low reorganization energy, good transition dipole moment alignment, high chromophore density, and low disorder, all enhancing long-range resonant energy transfer. Relieving exciton diffusion constraints has important implications for OPVs; large, ordered, and pure domains enhance charge separation and transport, and suppress recombination, thereby boosting fill factors. Further enhancements to diffusion lengths may even obviate the need for the bulk heterojunction morphology.
Diabetes mellitus is one of the common metabolic disorders acquiring around 2.8%of the world’s population and is anticipated to cross 5.4%by the year 2025.Since long back herbal medicines have been ...the highly esteemed source of medicine therefore,they have become a growing part of modern,high-tech medicine.In view of the above aspects the present review provides profiles of plants(65 species) with hypoglycaemic properties,available through literature source from various database with proper categorization according to the parts used,mode of reduction in blood glucose(insulinomimetic or insulin secretagugues activity) and active phyloconsliluents having insulin mimetics activity.From the review it was suggested that,plant showing hypoglycemic potential mainly belongs to the family Leguminoseae,Lamiaceae,Liliaceae,Cucurbitaceae, Asteraceae,Moraceae,Rosaceae and Araliaceae.The most active plants are Allium sativum. Gymnema sylvestre,Citrullus colocynthis,Trigonella foenum greacum,Momordica charantia and Ficuts bengalensis.The review describes some new bioactive drugs and isolated compounds from plants such as roseoside,epigallocatechin gallate,beta-pyrazol-1-ylalanine,cinchonain Ib,leucocyandin 3-O-beta-d-galactosyl cellobioside,leucopelargonidin-3- O-alpha-L rhamuoside,glycyrrhetinic acid,dehydrotrametenolic acid,strictinin,isostrictinin,pedunculagin, epicatechin and christinin-A showing significant insulinomimetic and antidiabetic activity with more efficacy than conventional hypoglycaemic agents.Thus,from the review majorly,the antidiabetic activity of medicinal plants is attributed to the presence of polyphenols,flavonoida, terpenoids,coumarins and other constituents which show reduction in blood glucose levels.The review also discusses the management aspect of diabetes mellitus using these plants and their active principles.
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•We for the first time develop a low-cost electrochemical immunosensor on paper for quantitative analysis of pancreatic cancer biomarker PEAK1.•The combination of electrochemical ...detection with gold nanoparticles enables high detection sensitivity.•Graphene oxide is drop-coated on carbon electrodes, providing a simple strategy to link antibodies to electrodes.•The immunosensor exhibits a low limit of detection of 10 pg mL−1 PEAK1, indicating high detection sensitivity for early cancer diagnosis.•This electrochemical platform has tremendous potential for point-of-care early diagnosis of a variety of cancers in resource-poor settings.
Due to the lack of specific early detection methods for pancreatic cancer, it usually goes undetected until it is advanced. By employing paper-based electrodes (PPEs), herein we for the first time developed a disposable low-cost paper-based immunosensor for rapid early quantitative detection of pancreatic cancer with a new biomarker, pseudopodium-enriched atypical kinase one, SGK269 (PEAK1). The immunosensor was constructed by fabricating PPEs immobilized with the versatile nanomaterial graphene oxide for the incorporation of antibodies to form an immunosensing platform, without the need of complicated surface modification. After it was confirmed that the PPEs exhibited excellent electrochemical properties, a sandwich-type electrochemical immunosensor was subsequently constructed by employing graphene oxide layers immobilized with anti-PEAK1, and the antibody conjugated with gold nanoparticles (AuNPs-tagged-Anti PEAK1). Further, spectral and surface characteristic studies confirmed the formation of the immunosensing platform. The immunosensor for PEAK1 exhibited a wide linear range between 10 pg mL−1 and 106 pg mL−1 with a low limit of detection (LOD) of 10 pg mL−1. The obtained results point towards rapid, sensitive, and specific early diagnosis of pancreatic cancer at the point of care and other low-resource settings.
Molecular dynamics simulations are widely employed to analyze water and ion permeation through nanoporous membranes for reverse osmosis applications. In such simulations, water models play an ...important role in accurately reproducing the properties of water. We investigated the water and ion transport across a hydroxyl (OH) functionalized graphene nanopore using six water models: SPC, SPC/E, SPC/Fw, TIP3P, TIP4P, and TIP4P/2005. The water flux thus obtained varied up to 84% between the models. The water and ion flux showed a correlation with the bulk transport properties of the models such as the diffusion coefficient and shear viscosity. We found that the hydrogen-bond lifetime, resulting from the partial charges of the model, influenced the flux. Our results are useful in the selection of a water model for computer simulations of desalination using nanomembranes. Our findings also suggest that lowering the hydrogen-bond lifetime and enhancing the rate of diffusion of water would lead to enhanced water/ion flux.
The coastal region bordering the East coast of India is a thickly populated belt exposed to high risk and vulnerability from natural hazards such as tropical cyclones. Tropical cyclone frequencies ...that develop over the Bay of Bengal (average of 5–6 per year) region are much higher as compared to the Arabian Sea thereby posing a high risk factor associated with storm surge, inland inundation, wind gust, intense rainfall, etc. The Odisha State in the East coast of India experiences the highest number of cyclone strikes as compared to West Bengal, Andhra Pradesh, and Tamil Nadu. To express the destructive potential resulting from tropical cyclones the Power Dissipation Index (PDI) is a widely used metric globally. A recent study indicates that PDI for cyclones in the present decade have increased about six times as compared to the past. Hence there is a need to precisely ascertain the coastal vulnerability and risk factors associated with high intense cyclones expected in a changing climate. As such there are no comprehensive studies attempted so far on the determination of Coastal Vulnerability Index (CVI) for Odisha coast that is highly prone to cyclone strikes. With this motivation, the present study makes an attempt to investigate the physical, environmental, social, and economic impacts on coastal vulnerability associated with tropical cyclones for the Odisha coast. The study also investigates the futuristic projection of coastal vulnerability over this region expected in a changing climate scenario. Eight fair weather parameters along with storm surge height and onshore inundation were used to estimate the Physical Vulnerability Index (PVI). Thereafter, the PVI along with social, economic, and environmental vulnerability was used to determine the overall CVI using the GIS based approach. The authors believe that the comprehensive nature of this study is expected to benefit coastal zone management authorities.
•Study performed analysis on Cyclone induced Coastal Vulnerability for Odisha.•Inundation volume is used as an indicator for assessment of Coastal Vulnerability.•Synaptic ArcGIS tool is used for assessment of composite vulnerability.•Coastal vulnerability is projected in response to climate change for Odisha coast.
As we make progress toward the 5G of wireless networks, the bit-per-joule energy efficiency (EE) becomes an important design criterion for sustainable evolution. In this regard, one of the key ...enablers for 5G is massive multiple-input multiple-output (MIMO) technology, where the BSs are equipped with an excess of antennas to achieve multiple orders of spectral and energy efficiency gains over current LTE networks. Here, we review and present a comprehensive discussion on techniques that further boost the EE gains offered by massive MIMO (MM). We begin with an overview of MM technology and explain how realistic power consumption models should be developed for MM systems. We then review prominent EE-maximization techniques for MM systems and identify a few limitations in the state-of-the-art. Next, we investigate EE-maximization in "hybrid MM systems," where MM operates alongside two other promising 5G technologies: millimeter wave and heterogenous networks. Multiple opportunities open up for achieving larger EE gains than with conventional MM systems because massive MIMO benefits mutually from the co-existence with these 5G technologies. However, such a co-existence also introduces several new design constraints, making EE-maximization non-trivial. A critical analysis of the state-of-the-art EE-maximization techniques for hybrid MM systems allows us to identify several open research problems which, if addressed, will immensely help operators in planning for energy- efficient 5G deployments.
Background & objectives: COVID-19 pandemic has taken a significant toll on the health of the people across the globe, including India, and is still continuing with its rapidly evolving second wave. ...Although the COVID-19 vaccines effectively prevent infection, yet some cases of infections have been reported post-vaccination, raising concerns about their efficacy and safety. This study was aimed to investigate the occurrence of SARS-CoV-2 infection among the symptomatic-vaccinated healthcare workers (HCWs) and to analyze the severity of their disease.
Methods: This retrospective study was done at a single multispecialty hospital, on the HCWs who have had COVID-19 vaccination, during the initial period of the vaccination drive (January 16 to April 24, 2021). The symptomatic post-vaccination infections in these HCWs were evaluated.
Results: Eighty five of 3235 (2.63%) vaccinated HCWs acquired the SARS-CoV-2 infection after vaccination, during the study period. Of these, 65 (76.5%) were fully vaccinated (FV), and 20 (23.5%) were partially vaccinated (PV) and the protection rate of vaccination was 97.4 per cent 95 % confidence interval (CI)=96.8-97.9. The odds ratio of acquiring infection among females was higher at 1.84 (95% CI=1.17-2.88; P=0.008) mainly because of their greater involvement in the patient care as nursing personnel. The chances of infections were the highest in the medical and nursing personnel, as compared to paramedical, administrative and supporting staff (P<0.001). Among the HCWs studied, only two required hospitalization (0.06%), none needed an intensive care unit (ICU) admission and there were no deaths.
Interpretation & conclusions: The COVID-19 infection after vaccination occurred in a smaller subset (2.63%) of HCWs, in both PV and the FV groups. These infections were primarily minor and did not lead to severe disease. Overall, the vaccination with ChAdOx1 nCoV-19 vaccine (recombinant) prevented SARS-CoV-2 severe infection in the HCWs, leading to ICU admission and deaths.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Desalination processes consume large amount of electricity and heat derived from fossil fuels to produce fresh water. In recent years, solar desalination emerged as a favorable method for sustainable ...fresh water production with less environmental impacts. A solar photovoltaic thermal collector is a combined system of solar photovoltaic and solar thermal collector that simultaneously generates electricity and thermal energy. The present work reviews photovoltaic thermal collector integrating desalination technologies such as solar still, humidification dehumidification, multiple effect distillation, reverse osmosis, multiple stage flash and membrane distillation. The primary focus is made on successful utilization of electricity and heat from the photovoltaic thermal collector in desalination systems to reduce cost, primary energy consumption and to improve overall system performance. Future opportunities and novel methods to improve/explore the photovoltaic thermal driven desalination systems are reported. Possibilities of photovoltaic thermal collector as energy source for other desalination technologies (electrodialysis, forward osmosis, vapor compression, adsorption desalination and etc.) are also presented. Comparative analysis shows that overall performance of photovoltaic thermal coupled desalination systems is better than desalination systems coupled with separate photovoltaic panel and/or solar thermal collector to meet the energy needs. The additional electricity generated from photovoltaic thermal desalination paves way for standalone desalination in remote location even though the initial costs are a tad higher.
•Solar PVT collector coupled desalination technologies are critically reviewed.•Additional electricity from PVT-desalination paves way for standalone desalination.•Comparisons, economic and environment aspects of PVT-desalination are discussed.•Observations, future opportunities and novel methods to be explored are reported.
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