Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recently emerged as a highly virulent respiratory pathogen that is known as the causative agent of coronavirus disease 2019 (COVID-19). Diarrhea is a common early symptom in a significant proportion of patients with SARS-CoV-2 infection. SARS-CoV-2 can infect and replicate in esophageal cells and enterocytes, leading to direct damage to the intestinal epithelium. The infection decreases the level of angiotensin-converting enzyme 2 receptors, thereby altering the composition of the gut microbiota. SARS-CoV-2 elicits a cytokine storm, which contributes to gastrointestinal inflammation. The direct cytopathic effects of SARS-CoV-2, gut dysbiosis, and aberrant immune response result in increased intestinal permeability, which may exacerbate existing symptoms and worsen the prognosis. By exploring the elements of pathogenesis, several therapeutic options have emerged for the treatment of COVID-19 patients, such as biologics and biotherapeutic agents. However, the presence of SARS-CoV-2 in the feces may facilitate the spread of COVID-19 through fecal-oral transmission and contaminate the environment. Thus gastrointestinal SARS-CoV-2 infection has important epidemiological significance. The development of new therapeutic and preventive options is necessary to treat and restrict the spread of this severe and widespread infection more effectively. Therefore, we summarize the key elements involved in the pathogenesis and the epidemiology of COVID-19-associated diarrhea.

In this paper, we present the first report on an organic conducting polymer film, which alone exhibits both superhydrophobicity and visible light photoactivity. The microstructure of poly(3-hexylthiophene) was optimized using controlled precipitation until superhydrophobic behavior was achieved. Photocatalytic tests employing visible light irradiation proved that polymer degrades the ethanol test molecule.Controlling the wettability of solid surfaces and solid/fluid interfaces is important for a myriad of applications. Surfaces with water contact angles higher than 1501 (superhydrophobicity) can exhibit self-cleaning effects, as found in lotus leaves in nature. 1,2For preparing artificial superhydrophobic interfaces, hydrophobic functionality and surface roughness are both needed. Typically, a microstructure is superimposed by nanostructures, and this dual roughness reduces the contact area between water and the surface, resulting in water-repellent properties.3,4 The second major class of self-cleaning surfaces is photocatalytic coatings, which chemically decompose organic pollutants upon light exposure -this process is known as photocatalysis. 5 The immobilization of photocatalyst nanoparticles in an appropriately structured binder or support material can lead to antimicrobial and self-cleaning properties, which expands the horizon of applications. State-of-the-art bifunctional materials, possessing superhydrophobic and photoreactive properties, 6 are semiconductor photocatalyst/organic polymer nanocomposites. 7,8 In such assemblies, low-energy hydrophobic polymers are employed as inert matrices to immobilize photocatalysts, exploiting their flexibility, low weight, impact resistance, and low cost. 9-11 At the same time, nanocomposite configuration has considerable drawbacks. Most importantly, the polymer binder might decrease the intrinsic photocatalytic activity of the inorganic component via both optical/electrical shielding and by forming a physical barrier between the photoactive surface and the material to be decomposed. In addition, photogenerated charge carriers may also degrade the binder itself, causing possible detachment of the composite from the substrate. In the search for conceptually new alternatives, conducting polymers (also called conjugated polymers or synthetic metals, CPs) deserve consideration as they may fulfil the above requirements alone, without the need for composite formation. The wettability of CPs depends greatly on their chemical structure and the used dopants.12 For example, a polypyrrole (PPy) film containing a perfluorinated dopant anion exhibited hydrophobicity (water contact angle 4901), while ClO 4 À -doped PPy was hydrophilic. 13 The synthesis of superhydrophobic CPs and the reversible control of their wettability between superhydrophobicity and superhydrophilicity were also demonstrated. 14,15 Although the photoactivity of CPs is well-known and has been exploited in organic solar photovoltaic 16 and photoelectrochemical cells, 17 photocatalytic studies of CPs alone ...

Autophagy is an intracellular catabolic process that controls infections both directly and indirectly via its multifaceted effects on the innate and adaptive immune responses. It has been reported that LPS stimulates this cellular process, whereas the effect of IL-36α on autophagy remains largely unknown. We therefore investigated how IL-36α modulates the endogenous and LPS-induced autophagy in THP-1 cells. The levels of LC3B-II and autophagic flux were determined by Western blotting. The intracellular localization of LC3B was measured by immunofluorescence assay. The activation levels of signaling pathways implicated in autophagy regulation were evaluated by using a phosphokinase array. Our results showed that combined IL-36α and LPS treatment cooperatively increased the levels of LC3B-II and Beclin-1, stimulated the autophagic flux, facilitated intracellular redistribution of LC3B, and increased the average number of autophagosomes per cell. The IL36α/LPS combined treatment increased phosphorylation of STAT5a/b, had minimal effect on the Akt/PRAS40/mTOR pathway, and reduced the levels of phospho-Yes, phospho-FAK, and phospho-WNK1. Thus, this cytokine/PAMP combination triggers pro-autophagic biased signaling by several mechanisms and thus cooperatively stimulates the autophagic cascade. An increased autophagic activity of innate immune cells simultaneously exposed to IL-36α and LPS may play an important role in the pathogenesis of Gram-negative bacterial infections.