In this task, you're given a paragraph from the research paper and your task is to generate a suitable title for the research paper based on the given paper. Under 100 words is a good title length.
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Question: Many new RNA pseudoknot structures have been detected and proposed in the past year. Although we are still waiting for the first detailed structure of a pseudoknot, their role in processes such as translational autoregulation or ribosomal frameshifting has been extensively studied and is now well established. Pseudoknot structures appear to play a pivotal role in small subunit ribosomal RNA and in the noncoding regions of viral RNAs. There are also strong indications that RNA pseudoknots are highly suitable structural motifs for the recognition and binding of proteins.

Answer: RNA pseudoknots

Question: Viruses use a limited set of host pathways for infection. These pathways represent bona fide antiviral targets with low likelihood of viral resistance. We identified the salicylanilide niclosamide as a broad range antiviral agent targeting acidified endosomes. Niclosamide is approved for human use against helminthic infections, and has anti-neoplastic and antiviral effects. Its mode of action is unknown. Here, we show that niclosamide, which is a weak lipophilic acid inhibited infection with pH-dependent human rhinoviruses (HRV) and influenza virus. Structure-activity studies showed that antiviral efficacy and endolysosomal pH neutralization co-tracked, and acidification of the extracellular medium bypassed the virus entry block. Niclosamide did not affect the vacuolar H + -ATPase, but neutralized coated vesicles or synthetic liposomes, indicating a proton carrier mode-of-action independent of any protein target. This report demonstrates that physico-chemical interference with host pathways has broad range antiviral effects, and provides a proof of concept for the development of host-directed antivirals.

Answer: Niclosamide Is a Proton Carrier and Targets Acidic Endosomes with Broad Antiviral Effects

Question: Single particle cryo-electron microscopy (cryoEM) is becoming widely adopted as a tool for structural characterization of biomolecules at near-atomic resolution. Vitrification of the sample to obtain a dense distribution of particles within a single field of view remains a major bottleneck for the success of such experiments. Here, we describe a simple and cost-effective method to increase the density of frozenhydrated particles on grids with holey carbon support films. It relies on performing multiple rounds of sample application and blotting prior to plunge freezing in liquid ethane. We show that this approach is generally applicable and significantly increases particle density for a range of samples, such as small protein complexes, viruses and filamentous assemblies. The method is versatile, easy to implement, minimizes sample requirements and can enable characterization of samples that would otherwise resist structural studies using single particle cryoEM. O 2017 Elsevier Inc. All rights reserved. Single particle cryo-electron microscopy (cryoEM) is becoming an increasingly important tool in structural biology (Nogales and Scheres, 2015; Cheng et al., 2015) . Due to recent advances in detector efficiency, microscope stability and image processing, the 3D structure of biomolecular complexes spanning a wide range of sizes, from haemoglobin to microtubules and intact viruses, can be reconstructed at (near-) atomic resolution (Bai et al., 2013; Brilot et al.,

Answer:
Vitrification after multiple rounds of sample application and blotting improves particle density on cryo-electron microscopy grids