Vibration Characteristics of Beam Structure Attached with Vibration Absorbers at its Vibrational Node and Antinode by Finite Element Analysis

In this study, the vibration characteristics of fixed ends beam are analysed after attached with dynamic vibration absorbers at vibrational node and antinode by simulation using ANSYS APDL. This study aim to obtain the best location and optimum number of DVAs placed on the fixed ends beam in order to reduce vibration of beam. The dynamic vibration absorber were attached to the fixed ends beam vibrational node and antinode for a total of three modes of vibration. The 0.84 m long beam is modelled by ANSYS and divided into 21 elements where each element is 0.04 m. A harmonic force, Fo of 28.84 N is exerted at node 3 of beam element. Modal analysis and harmonic analysis are carried out in this study to obtain the natural frequency and frequency response of the beam respectively. The vibration characteristics of fixed ends beam without DVA and beam attached with DVAs were compared. The simulation results show reduction of vibration amplitude of the beam especially when the DVA were attached at the vibrational antinode. The DVA amplitude increase when amplitude of beam decreases. From this study, it is proved that DVAs absorb vibration of the beam structure. The best position to attach DVAs is the vibrational antinode based on the modes of vibration. The increment of DVAs number will not affect the percentage reduction of vibration amplitude as long as the DVAs are placed at optimum location. &nbsp

Propagation of Drought: From Meteorological Drought to Agricultural and Hydrological Drought

Drought is a hazard that occurs everywhere in the world (both in dry and in wet areas). Despite the controversy regarding drought changes in the last decades [1–3], increases in drought intensity are clearly identified in some areas [4] and it is believed that although increased heating from global warming may not directly cause droughts, it is expected that when droughts occur, they are likely to set in quicker and be more intense [5]. Throughout its history, China has frequently suffered from drought disasters due to its monsoon climate and was regularly hit hard by droughts over the last decades. Although little evidence of an expansion of the area affected by droughts was found in China over the last 50 years [6], severe droughts in southwestern China in 2010 and the middle/lower Yangtze Basin and Huaihe River Basin in 2011 have drawn more attention from the research community as well as from the public and governments alike on the impacts and problems brought on by drought. Poor performance by China’s emergency response management during recent major drought events highlights the necessity of improving both drought preparedness and emergency response skills

Improving the uniformity of top emitting organic light emitting diodes using a hybrid electrode structure

Funding: The authors are grateful to the Engineering and Physical Sciences Research Council (grant EP/R035164/1) for financial support.Some applications of organic light-emitting diodes (OLEDs) require large area, high light output, and high uniformity. It is difficult to achieve these attributes simultaneously because of voltage drops in the contacts, which cannot easily satisfy high optical transparency and electrical conductivity simultaneously. In large area OLEDs, thin electrodes with high sheet resistance induce voltage drops across the devices, leading to non-uniform distribution of light. However, thick electrodes with low sheet resistance decrease the light output due to low transmittance. To overcome this trade-off, a multilayer hybrid electrode based on Ag (20 nm)/WO3/Ag (20 nm)/WO3 is designed to obtain high electrical conductance with low optical loss. Compared to conventional devices using a single Ag (40 nm) top electrode, there is a considerable increase in the external quantum efficiency (EQE) of the device using this electrode (from 11.5% to 25.5% at 1000 cd m−2), while maintaining similar sheet resistance. In addition, a large area (≈57 cm2) OLED with the hybrid electrode demonstrates a luminance uniformity of 77% as compared to a device using single silver electrode with uniformity of 66%. Therefore, the proposed Ag/WO3/Ag/WO3 hybrid electrode is a promising choice for the fabrication of efficient and uniform large-area OLEDs.Publisher PDFPeer reviewe

Hepatitis C Virus Infection Treatment: Recent Advances and New Paradigms in the Treatment Strategies

The advancement in hepatitis C virus (HCV) therapeutics has been profoundly enhanced by an improved understanding of viral life cycle in host cells, development of novel direct-acting antivirals (DAAs), and exploring other emerging treatment paradigms on the horizon. The approvals of first-, second-, and next-wave direct-acting antivirals highlight the swift pace of progress in the successful development of an expanding variety of therapeutic regimens for use in patients with chronic hepatitis C virus infection. Triple or quadruple therapies based on a combination of different direct-acting antivirals with or without pegylated interferon (IFN) and ribavirin (RBV) have raised the hopes to improve the current treatment strategies for other difficult-to-treat individuals. The development of more efficacious, well-tolerated, and cost-effective interferons with a low frequency of adverse events and short treatment durations is also in the pipeline. An experimental protective vaccine against hepatitis C virus demonstrated promise in preliminary human safety trials, and a larger phase II clinical trials are under consideration to further determine the efficacy of the vaccine. This pragmatic book chapter discusses the current state of knowledge in hepatitis C virus therapeutics and provides a conceptual framework of emerging and investigational treatment strategies directed against this silent epidemic

Hydrogels that listen to cells:a review of cell-responsive strategies in biomaterial design for tissue regeneration

The past decade has seen a decided move from static and passive biomaterials to biodegradable, dynamic, and stimuli responsive materials in the laboratory and the clinic. Recent advances towards the rational design of synthetic cell-responsive hydrogels-biomaterials that respond locally to cells or tissues without the input of an artificial stimulus-have provided new strategies and insights on the use of artificial environments for tissue engineering and regenerative medicine. These materials can often approximate responsive functions of a cell's complex natural extracellular environment, and must respond to the small and specific stimuli provided within the vicinity of a cell or tissue. In the current literature, there are three main cell-based stimuli that can be harnessed to create responsive hydrogels: (1) enzymes (2) mechanical force and (3) metabolites/small molecules. Degradable bonds, dynamic covalent bonds, and non-covalent or supramolecular interactions are used to provide responsive architectures that enable features ranging from cell selective infiltration to control of stem-cell differentiation. The growing ability to spatiotemporally control the behavior of cells and tissue with rationally designed responsive materials has the ability to allow control and autonomy to future generations of materials for tissue regeneration, in addition to providing understanding and mimicry of the dynamic and complex cellular niche

Study protocol for improving asthma outcomes through cross-cultural communication training for physicians: a randomized trial of physician training

Abstract Background Massive resources are expended every year on cross-cultural communication training for physicians. Such training is a focus of continuing medical education nationwide and is part of the curriculum of virtually every medical school in America. There is a pressing need for evidence regarding the effects on patients of cross-cultural communication training for physicians. There is a need to understand the added benefit of such training compared to more general communication. We know of no rigorous study that has assessed whether cross-cultural communication training for physicians results in better health outcomes for their patients. The current study aims to answer this question by enhancing the Physician Asthma Care Education (PACE) program to cross cultural communication (PACE Plus), and comparing the effect of the enhanced program to PACE on the health outcomes of African American and Latino/Hispanic children with asthma. Methods/Design A three-arm randomized control trial is used to compare PACE Plus, PACE, and usual care. Both PACE and PACE Plus are delivered in two, two-hour sessions over a period of two weeks to 5–10 primary care physicians who treat African American and Latino/Hispanic children with asthma. One hundred twelve physicians and 1060 of their pediatric patients were recruited who self-identify as African American or Latino/Hispanic and experience persistent asthma. Physicians were randomized into receiving either the PACE Plus or PACE intervention or into the control group. The comparative effectiveness of PACE and PACE Plus on clinician’s therapeutic and communication practices with the family/patient, children’s urgent care use for asthma, asthma control, and quality of life, and parent/caretaker satisfaction with physician performance will be assessed. Data are collected via telephone survey and medical record review at baseline, 9 months following the intervention, and 21 months following the intervention. Discussion This study aims to reduce disparities in asthma outcomes among African American and Latino/Hispanic children through cross-cultural communication training of their physicians and assessing the added value of this training compared to general communication. The results of this study will provide important information about the value of cross-cultural training in helping to address persistent racial disparities in outcomes. Trial registration ClinicalTrials.gov: NCT01251523 December 1, 2010http://deepblue.lib.umich.edu/bitstream/2027.42/109533/1/12909_2014_Article_948.pd

Highly efficient organic light-emitting diodes and light-emitting electrochemical cells employing multiresonant thermally activated delayed fluorescent emitters with bulky donor or acceptor peripheral groups

Jingxiang Wang thanks the China Scholarship Council (202006250026). We thank the Engineering and Physical Sciences Research Council (EP/R035164/1, EP/W015137/1, and EP/W007517/1) for support. Ludvig Edman and Shi Tang acknowledge financial support from the Swedish Research Council (2019-02345 and 2021–04778), the Swedish Energy Agency (50779-1 and P2021-00032), the Wallenberg Initiative Materials Science for Sustainability (WISE) funded by the Knut and Alice Wallenberg Foundation (WISE-AP01-D02), and the European Research Council for an ERC Advanced Grant (Project 101096650).Multiresonant thermally activated delayed fluorescence (MR-TADF) emitters have been the focus of extensive design efforts as they are recognized to show bright, narrowband emission, which makes them very appealing for display applications. However, the planar geometry and relatively large singlet?triplet energy gap lead to, respectively, severe aggregation-caused quenching (ACQ) and slow reverse intersystem crossing (RISC). Here, a design strategy is proposed to address both issues. Two MR-TADF emitters triphenylphosphine oxide (TPPO)-tBu-DiKTa and triphenylamine (TPA)-tBu-DiKTa have been synthesized. Twisted ortho-substituted groups help increase the intermolecular distance and largely suppress the ACQ. In addition, the contributions from intermolecular charge transfer states in the case of TPA-tBu-DiKTa help to accelerate RISC. The organic light-emitting diodes (OLEDs) with TPPO-tBu-DiKTa and TPA-tBu-DiKTa exhibit high maximum external quantum efficiencies (EQEmax) of 24.4% and 31.0%, respectively. Notably, the device with 25 wt% TPA-tBu-DiKTa showed both high EQEmax of 28.0% and reduced efficiency roll-off (19.9% EQE at 1000 cd m?2) compared to the device with 5 wt% emitter (31.0% EQEmax and 11.0% EQE at 1000 cd m?2). The new emitters were also introduced into single-layer light-emitting electrochemical cells (LECs), equipped with air-stable electrodes. The LEC containing TPA-tBu-DiKTa dispersed at 0.5 wt% in a matrix comprising a mobility-balanced blend-host and an ionic liquid electrolyte delivered blue luminance with an EQEmax of 2.6% at 425 cd m?2. The high efficiencies of the OLEDs and LECs with TPA-tBu-DiKTa illustrate the potential for improving device performance when the DiKTa core is decorated with twisted bulky donors.Peer reviewe

PHYTOTHERAPEUTIC POTENTIAL OF HERBAL SUPPLEMENTS FOR COVID-19

The current Coronavirus Disease-19 (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) has reportedly posed a significant threat to the global public health institution systems. The treatment has been supportive and not effective. Coupled with the lack of vaccine interventions, the search for effective therapeutic alternatives is still on. Herbal supplements have been used in the treatment of viral diseases for years and could serve as an alternative for COVID-19 therapy if the combinations are known and tested. Recent studies have proved that certain herbal supplements have exhibited antiviral activity against similar coronaviruses. Besides, molecular docking studies further proved the efficacy of the antiviral activity of the herbal supplements against SARS-CoV-2. However, there is still a need for in-vitro and in-vivo studies of the antiviral activity of these herbal supplements against SARS-CoV-2. Nevertheless, these herbal supplements have a high therapeutic potential for COVID-19 therapy. This study reveals the chemical composition of herbal supplements to come up with findings that can redefine research and development, risk analysis, and containment of the novel coronavirus disease