DNA-encoded chemistry technology yields expedient access to SARS-CoV-2 Mpro inhibitors.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed more than 4 million humans globally, but there is no bona fide Food and Drug Administration-approved drug-like molecule to impede the COVID-19 pandemic. The sluggish pace of traditional therapeutic discovery is poorly suited to producing targeted treatments against rapidly evolving viruses. Here, we used an affinity-based screen of 4 billion DNA-encoded molecules en masse to identify a potent class of virus-specific inhibitors of the SARS-CoV-2 main protease (Mpro) without extensive and time-consuming medicinal chemistry. CDD-1714, the initial three-building-block screening hit (molecular weight [MW] = 542.5 g/mol), was a potent inhibitor (inhibition constant [Ki] = 20 nM). CDD-1713, a smaller two-building-block analog (MW = 353.3 g/mol) of CDD-1714, is a reversible covalent inhibitor of Mpro (Ki = 45 nM) that binds in the protease pocket, has specificity over human proteases, and shows in vitro efficacy in a SARS-CoV-2 infectivity model. Subsequently, key regions of CDD-1713 that were necessary for inhibitory activity were identified and a potent (Ki = 37 nM), smaller (MW = 323.4 g/mol), and metabolically more stable analog (CDD-1976) was generated. Thus, screening of DNA-encoded chemical libraries can accelerate the discovery of efficacious drug-like inhibitors of emerging viral disease targets.

Removal of chlorine-contaminated groundwater by two-stage ozonation and biostimulation methods.

Trichloroethene (TCE) contamination is a critical environmental hazard, and the substrate options for its biostimulated remediation are limited. This study applied an ozonation-and-biostimulation process to remove TCE from groundwater. The substrate used, denoted as Transferred Energy Element (TEE), was composed of natural organic materials and had a low viscosity (2.914 cP). Ten batch experiments were conducted through the application of micro-nano bubbles (MNBs) and substrates (TEE and EOS® [emulsified oil substrate]). MNBs with an average diameter of 157.5-180.8 nm effectively degraded TCE and dichloroethane within 6 min. Biostimulation using the TEE substrate effectively degraded both TCE and vinyl chloride pollutants and reached a steady state after 25 days. The two-stage dechlorination procedure with MNB treatment as the first stage enhanced TCE removal via biostimulation. MNBs reduced the TCE concentration in the first 20 min, but increased the chloride (Cl-) concentration over the following five days (∼80 mg/L). The procedure with biostimulation as the first stage and 20 min ozonation as the second stage reduced the Cl- concentration by ∼10 mg/L. The Cl- concentrations rebounded after day 25 in the EOS environment. X-ray diffraction revealed that the released Na+ from the TEE settled with Cl- as minerals in the soil. The novel two-stage method for TCE removal was found to be more effective than solo MNB treatment or biostimulation.

High-Intensity Post-Stroke Rehabilitation Is Associated with Lower Risk of Pressure Ulcer Development in Patients with Stroke: Real-World Evidence from a Nationwide, Population-Based Cohort Study.

Background and Objectives: Multiple factors are associated with pressure ulcer (PU) development, including limited mobility following stroke. We performed a nationwide cohort study to investigate the impact of rehabilitation intensity on the incidence of post-stroke PU. Materials and Methods: Data of patients diagnosed with stroke between 2000 and 2012 were collected from the 2000 Longitudinal Health Insurance Database (Taiwan). Based on the number of rehabilitation sessions attended within 90 days of discharge, the rehabilitation intensity was classified as low, medium, or high. After adjusting for sociodemographic factors and comorbidities, the Cox proportional hazards model evaluated the risk of PU development during the 12-year follow-up period. Kaplan−Meier curves were used to estimate the cumulative incidence of PUs. Results: Our study included 18,971 patients who had their first episode of stroke. Of these, 9829 (51.8%) underwent rehabilitation therapy after discharge. Female patients and patients with a National Institutes of Health Stroke Scale (NIHSS) score >13 points, who commenced high-intensity post-stroke rehabilitation after discharge had a significantly lower risk of PU development than those who underwent low-intensity post-stroke rehabilitation after discharge. Cumulative survival analysis showed a significantly lower cumulative incidence of PU during the 12-year follow-up period in the high-intensity rehabilitation group. Conclusion: Compared with low-intensity post-stroke rehabilitation, high-intensity post-stroke rehabilitation after discharge from hospital is associated with a lower risk of post-stroke PU development, especially in female stroke patients and patients with a NIHSS score >13 points. High-intensity rehabilitation is also associated with a significantly lower cumulative incidence of PU events during the 12-year follow-up period.

Efficacy and safety of cervicothoracic epidural blood patch for patients with spontaneous intracranial hypotension.

BACKGROUND: Epidural blood patch (EBP) is a generally effective treatment for spontaneous intracranial hypotension (SIH) caused by cerebrospinal fluid (CSF) leakage through the spinal dura mater. It is still unclear; however, whether application near the leakage site (targeted EBP) is more effective than distal application (untargeted EBP). Further, EBP targeted to high thoracic or cervical spine levels is infrequent due to greater technical requirements and potential complications. Here, we examined the safety and efficacy of EBP applied to high thoracic or cervical spine levels. METHODS: We retrospectively reviewed the clinical and outcome data of 13 patients receiving cervical or high thoracic EBP for SIH. All patients were referred by neurologists following poor response to conservative treatment and presented with persistent headache aggravated by orthostatic changes. RESULTS: Neuroimaging confirmed CSF leakage and targeted EBP resulted in immediate pain improvement. Repeated injections provided additional improvement for patients with recurrent headache. No serious adverse events were documented during follow-up. CONCLUSION: Based on recent studies and our clinical experience, we conclude that EBP targeted to the high thoracic and cervical spine is safe and effective for early-stage SIH.

Design and construction of a stereochemically diverse piperazine-based DNA-encoded chemical library.

Here we report the successful construction of a novel, stereochemically diverse DNA-Encoded Chemical Library (DECL) by utilizing 24 enantiomerically pure trifunctional 2, 6- di-substituted piperazines as central cores. We introduce the concept of positional diversity by placing the DNA attachment at either of two possible sites on the piperazine scaffold. Using a wide range of building blocks, a diverse library of 77 million compounds was produced. Cheminformatic analysis demonstrates that this library occupies a wide swath of chemical space, and that the piperazine scaffolds confers different shape diversity compared to the commonly used triazine core.

Comparing natural red soil and irons for removal of phosphorus from wastewater using the multi-soil-layering system and its economic analysis.

The study uses an emerging soil treatment technology, the Multi-Soil Layering System (MSL), which is composed of the zeolite permeability layers (PL) and the soil mixture block layers (SMB). The experimental results show that the SMBs with iron particle (SMB-I) removed more than 83% of the total phosphorus (P) pollution in the water, and the outflow sewage concentration is 9.6 mg/L. In contrast, the SMBs with red clay (SMB-R) has 23% removal rate, and the outflow sewage concentration is 46.45 mg/L. Only 0.013 mg/L Fe concentration was detected in the SMB-R system and release of Fe from red soil is hardly achieved under neutral water environment. The SMB-R and SMB-I systems reduced 108.89 mg/g and 20.93 mg/g respectively and the SMB-R had higher removal efficiency of P per gram released Fe. The chromaticity problem of the effluent water in the SMB-I is up to 225 platinum cobalt, and that of the SMB-R is 172 platinum cobalt. Adding 10 g oyster shell (slice-only) and/or 0.65 g polyglutamic acid have effectively removed up to 99% 25-mg/L Fe in the effluent water; the chromaticity problem caused by Fe effluent was successfully solved. Furthermore, the iron particle has the highest unit cost among the materials in the SMBs (US$1.47/kg in lab and US$0.12/kg in field). Removal of 1 mg/L TP in the MSL system costs US$0.036 (by lab) in terms of removal TP rate in the laboratory was 83% and is economically feasible in field development.

Reactivity-Based Probe of the Iron(II)-Dependent Interactome Identifies New Cellular Modulators of Ferroptosis.

Ferroptosis is an iron-dependent form of cell death resulting from loss or inhibition of cellular machinery that protects from the accumulation of lipid hydroperoxides. Ferroptosis likely serves a tumor suppressing function in normal cellular homeostasis, but certain cancers exploit and become highly dependent on specific nodes of the pathway, presumably to survive under conditions of increased oxidative stress and elevated labile ferrous iron levels. Here we introduce Ferroptosis Inducing Peroxide for Chemoproteomics-1 (FIPC-1), a reactivity-based probe that couples Fenton-type reaction with ferrous iron to subsequent protein labeling via concomitant carbon-centered radical generation. We show that FIPC-1 induces ferroptosis in susceptible cell types and labels cellular proteins in an iron-dependent fashion. Use of FIPC-1 in a quantitative chemoproteomics workflow reproducibly enriched protein targets in the thioredoxin, oxidoreductase, and protein disulfide isomerase (PDI) families, among others. In further interrogating the saturable targets of FIPC-1, we identified the PDI family member P4HB and the functionally uncharacterized protein NT5DC2, a member of the haloacid dehalogenase (HAD) superfamily, as previously unrecognized modulators of ferroptosis. Knockdown of these target genes sensitized cells to known ferroptosis inducers, while PACMA31, a previously reported inhibitor of P4HB, directly induced ferroptosis and was highly synergistic with erastin. Overall, this study introduces a new reactivity-based probe of the ferrous iron-dependent interactome and uncovers new targets for the therapeutic modulation of ferroptosis.

C-N Coupling of DNA-Conjugated (Hetero)aryl Bromides and Chlorides for DNA-Encoded Chemical Library Synthesis.

DNA-encoded chemical library (DECL) screens are a rapid and economical tool to identify chemical starting points for drug discovery. As a robust transformation for drug discovery, palladium-catalyzed C-N coupling is a valuable synthetic method for the construction of DECL chemical matter; however, currently disclosed methods have only been demonstrated on DNA-attached (hetero)aromatic iodide and bromide electrophiles. We developed conditions utilizing an N-heterocyclic carbene-palladium catalyst that extends this reaction to the coupling of DNA-conjugated (hetero)aromatic chlorides with (hetero)aromatic and select aliphatic amine nucleophiles. In addition, we evaluated steric and electronic effects within this catalyst series, carried out a large substrate scope study on two representative (hetero)aryl bromides, and applied this newly developed method within the construction of a 63 million-membered DECL.

Synthesis of 5-substituted tetrazoles via DNA-conjugated nitrile.

A zinc bromide-catalyzed synthesis of 5-substituted tetrazoles via DNA-conjugated nitriles using sodium azide has been developed. The protocol offered moderate to excellent yields of tetrazoles with a broad range of substrates, including a variety of functionalized aromatic, heterocyclic, and aliphatic nitriles. In addition, the electronic effect within the substrate scope was evaluated. DNA fidelity was assessed by ligation efficiency and amplifiability analysis. The ability to generate tetrazoles expands the diversity of heterocycles in the preparation of DNA-encoded chemical libraries.

[Nursing Experience of a Child With Difficulty Breathing With End-Stage Niemann-Pick Disease Type C].

This case report describes a nursing experience providing end-of-life care to a child with Niemann-Pick disease type C. The period of nursing care was from April to June 2018. After comprehensive nursing and family assessment, dyspnea and caregiver's role strain were identified as the primary nursing-care problems. Niemann-Pick is a rare disease caused by genomic abnormalities. Patients with this disease are unable to metabolize lipids, which accumulate in organs, causing hepatosplenomegaly, dyspnea, and central nervous system degeneration. There is a lack of relevant experience in medical and nursing care due to the small number of cases worldwide. It is difficult to predict the progress of this disease and the life expectancy of the patient. The complex indications of this disease complicate the caregiver burden and process of end-of-life care. Thus, the multi-disciplinary team integrated the discharge preparations, symptom control skills, and related resources to build consensus with the family. We provided nursing care continuously from hospital to home as well as improved quality of care and family cohesion and reduced caregiver load. We hope that sharing this experience provides a reference for discharge planning and end-of-life care for children with rare diseases.

Estimation of greenhouse gas emissions from a wastewater treatment plant using membrane bioreactor technology.

Wastewater treatment plants (WWTPs) using membrane bioreactor (MBR) technology have been considered a significant source of greenhouse gas (GHG) emissions. This study chose a small-scale wastewater treatment plant using MBR technology to estimate its potential for GHG emissions. The total GHG emissions from this wastewater treatment plant ranged from 2,802 to 11,946 kg CO2 -eq/month within the 4-year study period, and they were mainly attributable to electricity consumption (79.94%) followed by chemical usages (17.13%) and on-site GHG emissions (2.93%). The on-site GHG emissions varied monthly, but most of them ranged from 80 to 160 kg CO2 -eq/month. The aeration tank was an important operating unit for GHG emissions. Off-site GHG emissions mainly came from carbon dioxide (CO2 ) emissions resulting from electricity consumption. The results of this study provide useful information about the potential of GHG emissions from WWTPs using MBR technology and indicate that WWTPs can be sustainably managed. PRACTITIONER POINTS: Wastewater treatment plants have been considered a source of greenhouse gas emissions. Total greenhouse gas emissions from the wastewater treatment plants using membrane bioreactor were mainly attributable to electricity consumption. On-site greenhouse gas emissions were relatively insignificant in this study.

Estimation of willingness-to-pay for the MSW disposal system by choice experiment approach: A case study of Taiwan.

In Taiwan, municipal solid waste (MSW) is separated into general, recyclable, and food waste categories. General waste must be packaged into pre-paid trash bags before final disposal. Recyclable items and food waste are collected separately to reduce the costs of using pre-paid trash bags. This study applied a choice experiment approach to evaluate marginal willingness-to-pay (WTP) in different MSW disposal system scenarios. Variables include cleanliness, location for purchasing pre-paid trash bags, frequency of waste collection, and distance to waste disposal. The results indicate that cleanliness, location, and distance influence public behavior, acceptance, and participation. Higher collection frequency decreases public acceptance. Some of the socio-economic variables of the respondents, including age, education, and marriage status, affect MSW management alternatives. The marginal WTP of the scenarios in this study ranged from US$0.04-0.07 per trash bag. Online purchasing of pre-paid trash bags is more cost-effective and should be encouraged. The results of this study provide useful information for the development of policies related to waste management systems.

Synthesis and activity of functionalizable derivatives of the serotonin (5-HT) 5-HT2A receptor (5-HT2AR) antagonist M100907.

The approach of tethering together two known receptor ligands, to be used as molecular probes for the study of G protein-coupled receptor (GPCR) systems, has proven to be a valuable approach. Selective ligands that possess functionality that can be used to link to other ligands, are useful in the development of novel antagonists and agonists. Such molecules can also be attached to reporter molecules, such as fluorophores, for the study of GPCR dimerization and its role in signaling. The highly selective serotonin (5-HT) 5-HT2A receptor (5-HT2AR) antagonist M100907 (volinanserin) is of clinical interest in the treatment of neurological and mental health disorders. Here, we synthesized the most active (+)-M100907 enantiomer as well as a series of derivatives that possessed either an alkyne or an azide. The triazole resulting from the dipolar cycloaddition of these groups did not interfere with the ability of the bivalent ligand to act as an antagonist. Thus, we have synthesized a number of compounds which will prove useful in elucidating the role of the 5-HT2AR in the central nervous system.

Branched silver nanowires on fluorine-doped tin oxide glass for simultaneous amperometric detection of H2O2 and of 4-aminothiophenol by SERS.

This study introduces a two-step method for the deposition of branched silver nanowires (AgNWs) on fluorine-doped tin oxide (FTO) glass. This material serves as both an active surface-enhanced Raman-scattering (SERS) substrate and as an enzyme-free electrochemical sensor for H2O2. This dual functionality is systematically studied. The AgNWs as the main trunk were first deposited on FTO by spray-coating. Silver branches were then electrochemically produced on the preformed NWs. Scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectrometry were employed to characterize morphology, composition and microstructure. SERS experiments show that the branched AgNW/FTO substrate exhibits excellent performance in detecting 4-aminothiophenol at an ultra-low concentration of 0.1 fM. Simultaneously, this material displays an excellent electrocatalytic response to H2O2 reduction at a concentration as low as 1 µM. The sensor has a rapid response and two linear analytical ranges that extend from 0.25 to 300 µM, and from 0.3 to 2.6 mM of H2O2, respectively. The ultrahigh sensitivity and satisfactory reproducibility highlights the merit of this hierarchical AgNW dendritic structure for sensing applications. Graphical abstract Branched silver nanowires can serve as both an active surface-enhanced Raman scattering substrate and as an electrochemical sensor for H2O2. This dual functionality is systematically investigated.

Effects of storage environment on the moisture content and microbial growth of food waste.

Food waste (FW) has become a critical issue in sustainable development as the world's population has increased. Direct incineration of FW remains the primary treatment option. The moisture content of FW may affect the energy efficiency of incineration. In Taiwan, FW, which includes raw (r-FW) and post-consumer (p-FW) waste, is often stored in freezers before pretreatment. This study evaluated the effects of storage environment on the moisture content and microbial growth of FW. Storage at 263 K was associated with the largest reduction in moisture content in both r-FW and p-FW. At 263 K, the moisture content of r-FW and p-FW was lowest at 96 and 72 h, respectively. The E.coli and total bacteria counts were steady over 120 h when stored at 263 K. Storage at 253 K required the greatest electricity consumption, followed by 263 K and 258 K. Based on the reduction of moisture content and increase in energy efficiency, it is suggested that FW is placed in temporary storage at 263 K before (pre)treatment. The results of this study will help waste-to-energy plants, incinerators, and waste management enterprises to implement proper (pre)treatment of FW for sustainable waste management.

Covalent Modulators of the Vacuolar ATPase.

The vacuolar H+ ATPase (V-ATPase) is a complex multisubunit machine that regulates important cellular processes through controlling acidity of intracellular compartments in eukaryotes. Existing small-molecule modulators of V-ATPase either are restricted to targeting one membranous subunit of V-ATPase or have poorly understood mechanisms of action. Small molecules with novel and defined mechanisms of inhibition are thus needed to functionally characterize V-ATPase and to fully evaluate the therapeutic relevance of V-ATPase in human diseases. We have discovered electrophilic quinazolines that covalently modify a soluble catalytic subunit of V-ATPase with high potency and exquisite proteomic selectivity as revealed by fluorescence imaging and chemical proteomic activity-based profiling. The site of covalent modification was mapped to a cysteine residue located in a region of V-ATPase subunit A that is thought to regulate the dissociation of V-ATPase. We further demonstrate that a previously reported V-ATPase inhibitor, 3-bromopyruvate, also targets the same cysteine residue and that our electrophilic quinazolines modulate the function of V-ATPase in cells. With their well-defined mechanism of action and high proteomic specificity, the described quinazolines offer a powerful set of chemical probes to investigate the physiological and pathological roles of V-ATPase.

Evaluation of greenhouse gas emissions from waste management approaches in the islands.

Concerns about waste generation and climate change have attracted worldwide attention. Small islands, which account for more than one-sixth of the global land area, are facing problems caused by global climate change. This study evaluated the greenhouse gas emissions from five small islands surrounding Taiwan. These islands - Penghu County, Liuqui Island, Kinmen County, Matsu Island and Green Island - have their own waste management approaches that can serve as a guideline for waste management with greenhouse gas mitigation. The findings indicate that the total annual greenhouse gas emissions of the islands ranged from 292.1 to 29,096.2 [metric] tonne CO2-equivalent. The loading waste volumes and shipping distances were positively related to greenhouse gas emissions from transportation. The greenhouse gas emissions from waste-to-energy plants, mainly carbon dioxide and nitrous oxide, can be offset by energy recovery (approximately 38.6% of greenhouse gas emissions from incineration). In addition, about 34% and 11% of waste generated on the islands was successfully recycled and composted, respectively. This study provides valuable insights into the applicability of a policy framework for waste management approaches for greenhouse gas mitigation.

Evaluating the operational risks of biomedical waste using failure mode and effects analysis.

The potential problems and risks of biomedical waste generation have become increasingly apparent in recent years. This study applied a failure mode and effects analysis to evaluate the operational problems and risks of biomedical waste. The microbiological contamination of biomedical waste seldom receives the attention of researchers. In this study, the biomedical waste lifecycle was divided into seven processes: Production, classification, packaging, sterilisation, weighing, storage, and transportation. Twenty main failure modes were identified in these phases and risks were assessed based on their risk priority numbers. The failure modes in the production phase accounted for the highest proportion of the risk priority number score (27.7%). In the packaging phase, the failure mode 'sharp articles not placed in solid containers' had the highest risk priority number score, mainly owing to its high severity rating. The sterilisation process is the main difference in the treatment of infectious and non-infectious biomedical waste. The failure modes in the sterilisation phase were mainly owing to human factors (mostly related to operators). This study increases the understanding of the potential problems and risks associated with biomedical waste, thereby increasing awareness of how to improve the management of biomedical waste to better protect workers, the public, and the environment.

Development of Specific, Irreversible Inhibitors for a Receptor Tyrosine Kinase EphB3.

Erythropoietin-producing human hepatocellular carcinoma (Eph) receptor tyrosine kinases (RTKs) regulate a variety of dynamic cellular events, including cell protrusion, migration, proliferation, and cell-fate determination. Small-molecule inhibitors of Eph kinases are valuable tools for dissecting the physiological and pathological roles of Eph. However, there is a lack of small-molecule inhibitors that are selective for individual Eph isoforms due to the high homology within the family. Herein, we report the development of the first potent and specific inhibitors of a single Eph isoform, EphB3. Through structural bioinformatic analysis, we identified a cysteine in the hinge region of the EphB3 kinase domain, a feature that is not shared with any other human kinases. We synthesized and characterized a series of electrophilic quinazolines to target this unique, reactive feature in EphB3. Some of the electrophilic quinazolines selectively and potently inhibited EphB3 both in vitro and in cells. Cocrystal structures of EphB3 in complex with two quinazolines confirmed the covalent linkage between the protein and the inhibitors. A "clickable" version of an optimized inhibitor was created and employed to verify specific target engagement in the whole proteome and to probe the extent and kinetics of target engagement of existing EphB3 inhibitors. Furthermore, we demonstrate that the autophosphorylation of EphB3 within the juxtamembrane region occurs in trans using a specific inhibitor. These exquisitely specific inhibitors will facilitate the dissection of EphB3's role in various biological processes and disease contribution.

Treatment and prognosis of subdural hematoma in patients with spontaneous intracranial hypotension.

OBJECTIVE: The objective of this article is to elucidate the outcome, prognostic predictors and timing of surgical intervention for subdural hematoma (SDH) in patients with spontaneous intracranial hypotension (SIH). METHODS: Patients with SDH were identified retrospectively from 227 consecutive SIH patients. Data were collected on demographics, clinical courses, neuroimaging findings, and treatment of SDH, which was later divided into conservative treatment, epidural blood patches (EBP), and surgical intervention. Poor outcome was defined as severe neurological sequelae or death. RESULTS: Forty-five patients (20%) with SDH (mean maximal thickness 11.9 ± 6.2 mm) were recruited. All 15 patients with SDH <10 mm achieved good outcomes by either conservative treatment or EBP. Of 30 patients with SDH ≥10 mm, patients with uncal herniation (n = 3) had poor outcomes, even after emergent surgical evacuation (n = 2), compared to those without (n = 27) (100% vs. 0%, p < 0.001). Fourteen patients underwent surgical evacuation, resulting in good outcomes in all 12 who received early intervention and poor outcomes in the remaining two who received delayed intervention after Glasgow Coma Scale (GCS) score ≤8 (100% vs. 0%, p = 0.01). CONCLUSIONS: Uncal herniation results in poor outcomes in patients with SIH complicated with SDH. In individuals with SDH ≥10 mm and decreased GCS scores, early surgical evacuation might prevent uncal herniation.