In-cell bioluminescence resonance energy transfer (BRET)-based assay uncovers ceritinib and CA-074 as SARS-CoV-2 papain-like protease inhibitors.

Papain-like protease (PLpro) is an attractive anti-coronavirus target. The development of PLpro inhibitors, however, is hampered by the limitations of the existing PLpro assay and the scarcity of validated active compounds. We developed a novel in-cell PLpro assay based on BRET and used it to evaluate and discover SARS-CoV-2 PLpro inhibitors. The developed assay demonstrated remarkable sensitivity for detecting the reduction of intracellular PLpro activity while presenting high reliability and performance for inhibitor evaluation and high-throughput screening. Using this assay, three protease inhibitors were identified as novel PLpro inhibitors that are structurally disparate from those previously known. Subsequent enzymatic assays and ligand-protein interaction analysis based on molecular docking revealed that ceritinib directly inhibited PLpro, showing high geometric complementarity with the substrate-binding pocket in PLpro, whereas CA-074 methyl ester underwent intracellular hydrolysis, exposing a free carboxyhydroxyl group essential for hydrogen bonding with G266 in the BL2 groove, resulting in PLpro inhibition.

Preparation of S-C3N4/AgCdS Z-Scheme Heterojunction Photocatalyst and Its Effectively Improved Photocatalytic Performance.

In this study, S-doped graphitic carbon nitride (S-C3N4) was prepared using the high-temperature polymerization method, and then S-C3N4/AgCdS heterojunction photocatalyst was obtained using the chemical deposition method through loading Ag-doped CdS nanoparticles (AgCdS NPs) on the surface of S-C3N4. Experimental results show that the AgCdS NPs were evenly dispersed on the surface of S-C3N4, indicating that a good heterojunction structure was formed. Compared to S-C3N4, CdS, AgCdS and S-C3N4/CdS, the photocatalytic performance of S-C3N4/AgCdS has been significantly improved, and exhibits excellent photocatalytic degradation performance of Rhodamine B and methyl orange. The doping of Ag in collaboration with the construction of a Z-scheme heterojunction system promoted the effective separation and transport of the photogenerated carriers in S-C3N4/AgCdS, significantly accelerated its photocatalytic reaction process, and thus improved its photocatalytic performance.

Design, Synthesis, and Biological Evaluation of Benzimidazole Derivatives as Potential Lassa Virus Inhibitors.

The Lassa virus (LASV) causes Lassa fever, a highly infectious and lethal agent of acute viral hemorrhagic fever. At present, there are still no effective treatments available, creating an urgent need to develop novel therapeutics. Some benzimidazole compounds targeting the arenavirus envelope glycoprotein complex (GPC) are promising inhibitors of LASV. In this study, we synthesized two series of LASV inhibitors based on the benzimidazole structure. Lentiviral pseudotypes bearing the LASV GPC were established to identify virus entry inhibitors. Surface plasmon resonance (SPR) was further used to verify the binding activities of the potential compounds. Compounds 7d-Z, 7h-Z, 13c, 13d, and 13f showed relatively excellent antiviral activities with IC50 values ranging from 7.58 to 15.46 nM and their SI values above 1251. These five representative compounds exhibited stronger binding affinity with low equilibrium dissociation constants (KD < 8.25 × 10-7 M) in SPR study. The compound 7h-Z displayed the most potent antiviral activity (IC50 = 7.58 nM) with a relatively high SI value (2496), which could be further studied as a lead compound. The structure-activity relationship indicated that the compounds with lipophilic and spatially larger substituents might possess higher antiviral activity and a much larger safety margin. This study will provide some good guidance for the development of highly active compounds with a novel skeleton against LASV.

Naphthoquine: A Potent Broad-Spectrum Anti-Coronavirus Drug In Vitro.

COVID-19 has spread around the world and caused serious public health and social problems. Although several vaccines have been authorized for emergency use, new effective antiviral drugs are still needed. Some repurposed drugs including Chloroquine, Hydroxychloroquine and Remdesivir were immediately used to treat COVID-19 after the pandemic. However, the therapeutic effects of these drugs have not been fully demonstrated in clinical studies. In this paper, we found an antimalarial drug, Naphthoquine, showed good broad-spectrum anti-coronavirus activity. Naphthoquineinhibited HCoV-229E, HCoV-OC43 and SARS-CoV-2 replication in vitro, with IC50 = 2.05 ± 1.44 µM, 5.83 ± 0.74 µM, and 2.01 ± 0.38 µM, respectively. Time-of-addition assay was also performed to explore at which stage Naphthoquine functions during SARS-CoV-2 replication. The results suggested that Naphthoquine may influence virus entry and post-entry replication. Considering the safety of Naphthoquine was even better than that of Chloroquine, we think Naphthoquine has the potential to be used as a broad-spectrum drug for coronavirus infection.

Viral polymerase inhibitors T-705 and T-1105 are potential inhibitors of Zika virus replication.

Since 2015, 69 countries and territories have reported evidence of vector-borne Zika virus (ZIKV) transmission. Currently, there are no effective licensed vaccines or drugs available for the treatment or prevention of ZIKV infection. We tested a series of compounds for their ability to inhibit ZIKV replication in cell culture. The compounds in T-705 (favipiravir) and T-1105 were found to have antiviral activity, suggesting that these compounds are promising candidates for further development as specific antiviral drugs against ZIKV.

Fault diagnosis of accelerometer servo circuit output saturation based on feature electrical parameters extraction.

The servo circuit of quartz flexible accelerometer is an extremely vital microelectronic device in inertial system. The paper introduces the traditional analysis process about output saturation fault of accelerometer servo circuit. For the shortcomings of traditional analysis methods, a fault diagnosis method based on feature electrical parameters extraction is proposed. According to the fault phenomenon, combined with the modular characteristics of hybrid integrated circuits, the feature electrical parameters of fault modes are extracted, and the fault modes' judgment basis is set. By the judgment results of the feature electrical parameters of the fault circuit, the circuit with output saturation fault caused by the electrical damage to the differential capacitance detector and other faults can be located quickly and accurately, and it is verified by the analysis of faulty circuit samples. Targeted for these faults, the improvement measures are put forward. This analysis method improves the fault diagnosis efficiency and reliability about the accelerometer servo circuit, and has guiding significance for enhancing the success rate of the failure analysis in the hybrid integrated circuits.

Performance Enhancement of Ti/IrO2-Ta2O5 Anode through Introduction of Tantalum-Titanium Interlayer via Double-Glow Plasma Surface Alloying Technology.

Ti/IrO2-Ta2O5 electrodes are extensively utilized in the electrochemical industries such as copper foil production, cathodic protection, and wastewater treatment. However, their performance degrades rapidly under high current densities and severe oxygen evolution conditions. To address this issue, we have developed a composite anode of Ti/Ta-Ti/IrO2-Ta2O5 with a Ta-Ti alloy interlayer deposited on a Ti substrate by double-glow plasma surface alloying, and the IrO2-Ta2O5 surface coating prepared by the traditional thermal decomposition method. This investigation indicates that the electrode with Ta-Ti alloy interlayer reduces the agglomerates of precipitated IrO2 nanoparticles and refines the grain size of IrO2, thereby increasing the number of active sites and enhancing the electrocatalytic activity. Accelerated lifetime tests demonstrate that the Ti/Ta-Ti/IrO2-Ta2O5 electrode exhibits a much higher stability than the Ti/IrO2-Ta2O5 electrode. The significant improvement in electrochemical stability is attributed to the Ta-Ti interlayer, which offers high corrosion resistance and effective protection for the titanium substrate.

In vitro interaction of naphthoquine with ivermectin, atovaquone, curcumin, and ketotifen in the asexual blood stage of Plasmodium falciparum 3D7.

Naphthoquine is a promising candidate for antimalarial combination therapy. Its combination with artemisinin has demonstrated excellent efficacy in clinical trials conducted across various malaria-endemic areas. A co-formulated combination of naphthoquine and azithromycin has also shown high clinical efficacy for malaria prophylaxis in Southeast Asia. Developing new combination therapies using naphthoquine will provide additional arsenal responses to the growing threat of artemisinin resistance. Furthermore, due to its long half-life, the possible interaction of naphthoquine with other drugs also needs attention. However, studies on its pharmacodynamic interactions with other drugs are still limited. In this study, the in vitro interactions of naphthoquine with ivermectin, atovaquone, curcumin, and ketotifen were evaluated in the asexual stage of Plasmodium falciparum 3D7. By using the combination index analysis and the SYBR Green I-based fluorescence assay, different interaction patterns of selected drugs with naphthoquine were revealed. Curcumin showed a slight but significant synergistic interaction with naphthoquine at lower effect levels, and no antagonism was observed across the full range of effect levels for all tested ratios. Atovaquone showed a potency decline when combined with naphthoquine. For ivermectin, a significant antagonism with naphthoquine was observed at a broad range of effect levels below 75% inhibition, although no significant interaction was observed at higher effect levels. Ketotifen interacted with naphthoquine similar to ivermectin, but significant antagonism was observed for only one tested ratio. These findings should be helpful to the development of new naphthoquine-based combination therapy and the clinically reasonable application of naphthoquine-containing therapies. IMPORTANCE: Pharmacodynamic interaction between antimalarials is not only crucial for the development of new antimalarial combination therapies but also important for the appropriate clinical use of antimalarials. The significant synergism between curcumin and naphthoquine observed in this study suggests the potential value for further development of new antimalarial combination therapy. The finding of a decline in atovaquone potency in the presence of naphthoquine alerts to a possible risk of treatment or prophylaxis failure for atovaquone-proguanil following naphthoquine-containing therapies. The observation of antagonism between naphthoquine and ivermectin raised a need for concern about the applicability of naphthoquine-containing therapy in malaria-endemic areas with ivermectin mass drug administration deployed. Considering the role of atovaquone-proguanil as a major alternative when first-line artemisinin-based combination therapy is ineffective and the wide implementation of ivermectin mass drug administration in malaria-endemic countries, the above findings will be important for the appropriate clinical application of antimalarials involving naphthoquine-containing therapies.

Disulfide-incorporated lipid prodrugs of cidofovir: Synthesis, antiviral activity, and release mechanism.

The double-stranded DNA (dsDNA) viruses represented by adenovirus and monkeypox virus, have attracted widespread attention due to their high infectivity. In 2022, the global outbreak of mpox (or monkeypox) has led to the declaration of a Public Health Emergency of International Concern. However, to date therapeutics approved for dsDNA virus infections remain limited and there are still no available treatments for some of these diseases. The development of new therapies for treating dsDNA infection is in urgent need. In this study, we designed and synthesized a series of novel disulfide-incorporated lipid conjugates of cidofovir (CDV) as potential candidates against dsDNA viruses including vaccinia virus (VACV) and adenovirus (AdV) 5. The structure-activity relationship analyses revealed that the optimum linker moiety was C2H4 and the optimum aliphatic chain length was 18 or 20 atoms. Among the synthesized conjugates, 1c exhibited more potency against VACV (IC50 = 0.0960 µM in Vero cells; IC50 = 0.0790 µM in A549 cells) and AdV5 (IC50 = 0.1572 µM in A549 cells) than brincidofovir (BCV). The transmission electron microscopy (TEM) images revealed that the conjugates could form micelles in phosphate buffer. The stability studies in the GSH environment demonstrated that the formation of micelles in phosphate buffer might protect the disulfide bond from glutathione (GSH) reduction. The dominant means of the synthetic conjugates to liberate the parent drug CDV was by enzymatic hydrolysis. Furthermore, the synthetic conjugates remained sufficiently stable in simulated gastric fluid (SGF), simulated intestinal fluid (SIF), and pooled human plasma, which indicated the possibility for oral administration. These results indicated 1c may be a broad-spectrum antiviral candidate against dsDNA viruses with potential oral administration. Moreover, modification of the aliphatic chain attached to the nucleoside phosphonate group was involved as an efficient prodrug strategy for the development of potent antiviral candidates.

Molecular characterization and transcriptional response to TiO2-GO nanomaterial exposure of two molt-related genes in the juvenile prawn, Macrobrachium rosenbergii.

In recent years, with the widespread use of TiO2-GO nanocomposite in industry, especially in the remediation of water environments, its toxic effects on aquatic organisms have received increasing attention. As molting is extremely important for crustaceans in their growth, in this study, we cloned the full-length cDNA sequences of two key genes related to molting, nuclear hormone receptor E75 (E75) and nuclear hormone receptor HR3 (HR3), in Macrobrachium rosenbergii, examined the gene expression profile, and investigated their toxicological effects on crustacean molting through nanomaterial exposure. The amino acid sequences for E75 and HR3 were respectively determined to encode 1138 and 363 acid residues. Sequence analysis showed that both E75 and HR3 contain a HOLI domain, with the E75 of M. rosenbergii being more closely related to the E75 of Palaemon carinicauda. These two genes were expressed at the highest levels in muscle, followed by hepatopancreas. The results showed that the expressions of E75 and HR3 in hepatopancreas and muscle tissues were significantly decreased after exposure to 0.1 mg/L of TiO2-GO composite nanoparticles (P < 0.05). This study will serve as a foundation for subsequent research into the evaluation of nanomaterial toxicity on crustacean species.

Orthogonal dual reporter-based gain-of-signal assay for probing SARS-CoV-2 3CL protease activity in living cells: inhibitor identification and mutation investigation.

ABSTRACTThe main protease (3-chymotrypsin-like protease, 3CLpro) of SARS-CoV-2 has become a focus of anti-coronavirus research. Despite efforts, drug development targeting 3CLpro has been hampered by limitations in the currently available activity assays. Additionally, the emergence of 3CLpro mutations in circulating SARS-CoV-2 variants has raised concerns about potential resistance. Both emphasize the need for a more reliable, sensitive, and facile 3CLpro assay. Here, we report an orthogonal dual reporter-based gain-of-signal assay for measuring 3CLpro activity in living cells. It builds on the finding that 3CLpro induces cytotoxicity and reporter expression suppression, which can be rescued by its inhibitor or mutation. This assay circumvents most limitations in previously reported assays, especially false positives caused by nonspecific compounds and signal interference from test compounds. It is also convenient and robust for high throughput screening of compounds and comparing the drug susceptibilities of mutants. Using this assay, we screened 1789 compounds, including natural products and protease inhibitors, with 45 compounds that have been reported to inhibit SARS-CoV-2 3CLpro among them. Except for the approved drug PF-07321332, only five of these inhibit 3CLpro in our assays: GC376; PF-00835231; S-217622; Boceprevir; and Z-FA-FMK. The susceptibilities of seven 3CLpro mutants prevalent in circulating variants to PF-07321332, S-217622, and GC376 were also assessed. Three mutants were identified as being less susceptible to PF-07321322 (P132H) and S-217622 (G15S, T21I). This assay should greatly facilitate the development of novel 3CLpro-targeted drugs and the monitoring of the susceptibility of emerging SARS-CoV-2 variants to 3CLpro inhibitors.

Properties of SS304 Modified by Nickel-Cobalt Alloy Coating with Cauliflower-Shaped Micro/Nano Structures in Simulated PEMFC Cathode Environment.

This study presents the corrosion behavior and surface properties of SS304 modified by electrodeposited nickel-cobalt (Ni-Co) alloy coating with cauliflower-shaped micro/nano structures (Ni-Co/SS304) in the simulated PEMFC cathodic environment. The hydrophobicity of the as-prepared Ni-Co alloy coating can be improved simply by low-temperature annealing. The morphology and composition of the Ni-Co/SS304 were analyzed and characterized by SEM, EDS, XRD, and XPS. The polarization, wettability, and ICR tests were respectively conducted to systemically evaluate the performance of Ni-Co/SS304 in the simulated PEMFC cathode environment. As revealed by the results, the Ni-Co/SS304 can maintain its hydrophobicity under hot-water droplets as high as 80 °C and demonstrates higher conductivity than the bare SS304 substrate before and after polarization (0.6 V vs. SCE, 5 h), which is of great significance to improve the surface hydrophobicity and conductivity of bipolar plates.

Performance of SS304 Modified by Silver Micro/Nano-Dendrite Coating with Hot-Water Super-Repellency in Simulated PEMFC Cathode Environment.

In this study, an silver (Ag) plating with micro/nano-dendrite structures is prepared on the 304 stainless steel (SS304) surface by potentiostatic deposition (Ag/SS304). After being modified by n-dodecyl mercaptan (NDM) with the low surface energy, the obtained sample (NDM@Ag/SS304) exhibits stable superhydrophobicity and excellent hot-water repellency. The surface morphology and composition of NDM@Ag/SS304 are analyzed by scanning electron microscope (SEM), X-ray spectrometer (EDS), X-ray diffractometer (XRD), and X-ray photoelectron spectrometer (XPS) characterization. The electrochemical measurements, tests of water contact angle (WCA), and interfacial contact resistance (ICR) are employed to systematically study the performance of the NDM@Ag/SS304 in the simulated cathode environment of proton exchange membrane fuel cell (PEMFC). The results show that the NDM@Ag/SS304 has high corrosion potential (~0.25 V) and low corrosion current density (~4.04 µA/cm2); after potentiostatic polarization (0.6 V, 5 h), the NDM@Ag/SS304 also shows high superhydrophobic stability.

Spray-Dried Inhalable Powder Formulations of Gentamicin Designed for Pneumonic Plague Therapy in a Mouse Model.

Infection with Yersinia pestis (Y. pestis) may cause pneumonic plague, which is inevitably fatal without treatment. Gentamicin (GM), an aminoglycoside antibiotic, is a drug commonly used in the treatment of plague. However, it requires repeated intramuscular or intravenous administration. Pulmonary drug delivery is noninvasive, with the advantages of local targeting and reduced risk of systemic toxicity. In this study, GM powders were prepared using spray-drying technology. The powders displayed good physical and chemical properties and met the requirements for human pulmonary inhalation. The formulation of the powders was optimized using a 32 full factorial design. A formulation of 15% (w/w) of L-leucine was prepared, and the spray-drying process parameters using an inlet temperature of 120°C and a 15% pump rate were determined to produce the best powder. In addition, the optimized GM spray-dried powders were characterized in terms of morphology, crystallinity, powder fluidity, and aerodynamic particle size distribution analysis. In a mouse model of pneumonic plague, we compared the therapeutic effects among three administration routes, including subcutaneous injection, liquid atomization, and dry powder atomization. In conclusion, our data suggest that inhalation therapy with GM spray-dried powders is an effective treatment for pneumonic plague.

Experimental Hong-Ou-Mandel interference using two independent heralded single-photon sources.

Hong-Ou-Mandel (HOM) interference is one of the most important experimental phenomena in quantum optics. It has drawn considerable attention with respect to quantum cryptography and quantum communication because of the advent of the measurement device independent (MDI) quantum key distribution (QKD) protocol. Here, we realize HOM interference, having a visibility of approximately 38.1%, using two independent heralded single-photon sources (HSPSs). The HOM interference between two independent HSPSs is a core technology for realizing the long-distance MDI QKD protocol, the quantum coin-tossing protocol, and other quantum cryptography protocols.

The Anti-Inflammatory and Antiapoptotic Effects of Nicorandil in Antisepsis Cardiomyopathy.

OBJECTIVE: To observe the effect of nicorandil on septic rats and explore the possible mechanism of its myocardial protection, so as to provide theoretical basis for the treatment of septic cardiomyopathy. METHODS: Sixty male clean SD rats were selected as the research objects and randomly divided into 3 groups by random number method: sham operation group (sham group), cecal ligation and perforation group (CLP group), nicorandil treatment group (nicorandil+CLP group). After the operation, the nicorandil group was pumped with nicorandil diluent 1 ml/h (2 mg/kg/h) with a micropump for 6 hours. The sham group and CLP group were pumped with the same amount of normal saline 1 ml/h for a total of 6 hours. After 24 hours, the survival of the rats in each group was observed. The expression of troponin I (cTnI), tumor necrosis factor α (TNF-α), and interleukin-1ß (IL-1ß) in the serum was detected. Then, the ventricle was harvested for the observation of the pathological changes of myocardium. Quantitative real-time polymerase chain reaction and immunostaining were used to detect myocardial tissue apoptosis, and Western blot methods were used to detect protein expression changes in nuclear factor-κB (NF-κB) pathways. RESULTS: 24 hours after operation, the survival rate of the rats in the CLP group was 60%. There was a large amount of necrosis of myocardial cells and inflammatory cell infiltration. The survival rate of rats in the nicorandil+CLP group was 75%. Compared with the CLP group, the necrosis of myocardial cells was reduced, and there was still a small amount of inflammatory cell infiltration. In the CLP group, myocardial inflammation and apoptosis were significant, and NF-κB pathway was activated. On the contrary, the NF-κB pathway in the nicorandil+CLP group was inhibited, and the expression of inflammatory factors and apoptosis factors was inhibited. CONCLUSION: Nicorandil can reduce the release of inflammatory factors in septic rats, improve the inflammatory response, reduce myocardial damage, and play a myocardial protective effect. Its mechanism may be related to the inhibition of the activation of NF-κB signaling pathway.

Synthesis and in vivo antimalarial activity of novel naphthoquine derivatives with linear/cyclic structured pendants.

AIM: Naphthoquine (NQ) was discovered by our institute as an antimalarial candidate in 1980s, and currently employed as an artemisinin-based combination therapy partner drug. Resistance to NQ was found in mouse model in laboratory, and might emerge in future as widely used. METHODOLOGY: We herein report the design and synthesis of NQ derivatives by replacing t-butyl moiety with linear/cyclic structured pendants. All the target compounds 6a-l and intermediates 5a-h were tested for their in vivo antimalarial activity against Plasmodium berghei K173 strain in mice. RESULTS: Compounds 6a and 6j were found to have a comparable or slightly more potent activity (the 50% effective dose [ED50], which is required to decrease parasitemia by 50%: 0.38-0.43 mg/kg) than NQ (ED50: 0.48 mg/kg). CONCLUSION: The newly designed compounds 6a and 6j might be promising antimalarial candidates for further research.

Long-term clinical efficacy and safety of adding cilostazol to dual antiplatelet therapy after drug-eluting stent implantation in coronary arteries: A meta-analysis of randomized controlled trials.

OBJECTIVE: To assess the long-term clinical efficacy and safety of adding cilostazol (TAT) to conventional dual antiplatelet therapy (DAT) for patients undergoing drug-eluting stent (DES) implantation in coronary arteries. METHODS: We performed PUBMED, MEDLINE, EMBASE, and Cochrane CENTRAL searches for randomized clinical trials of TAT versus DAT in patients after DES implantation with criteria to include trials with a follow-up of more than 6 months. RESULTS: Seven RCTs with a total of 3487 patients were included in this review. The meta-analysis showed that TAT was associated with a significant reduction in major adverse cardiac events (MACEs) (relative risk (RR)=0.66; 95% CI=0.50-0.88), target lesion revascularization (TLR) (RR=0.61, 95% CI=0.43-0.84), target vessel revascularization (TVR) (RR=0.53, 95% CI=0.37-0.75), in-stent restenosis (RR=0.64, 95% CI=0.44-0.85), in-segment restenosis (RR=0.58, 95% CI=0.43-0.79, P<.01), in-stent late loss (LL) (standardized mean difference (SMD)=-0.21, 95% CI=0.32-0.17), and in-segment LL (SMD=-0.27, 95% CI=-0.38-0.16). TAT also did not appear to significantly alter any of the other meta-analysis secondary efficacy outcomes and had similar rates of bleeding, but TAT had significantly higher rates of rash, gastrointestinal side-effects, headache and drug discontinuation. CONCLUSIONS: Compared with standard DAT, the long-term use of TAT in patients after DES implantation gave more benefits in reducing the incidence of MACEs, TLR, TVR, in-stent and in-segment LL and restenosis without increasing bleeding but was associated with an increase in minor adverse events.