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Many drugs can bind directly to proteins or be bioactivated by metabolizing enzymes to form reactive metabolites (RMs) that rapidly bind to proteins to form drug-protein conjugates or metabolite-protein conjugates (DMPCs). The close relationship between DMPCs and idiosyncratic adverse drug reactions (IADRs) has been recognized; drug discovery teams tend to avoid covalent interactions in drug discovery projects. Covalent interactions in DMPCs can provide high potency and long action duration and conquer the intractable targets, inspiring drug design, and development. This forms the dual role feature of DMPCs. Understanding the functional implications of DMPCs in IADR control and therapeutic applications requires precise identification of these conjugates from complex biological samples. While classical biochemical methods have contributed significantly to DMPC detection in the past decades, the low abundance and low coverage of DMPCs have become a bottleneck in this field. An emerging transformation toward shotgun proteomics is on the rise. The evolving shotgun proteomics techniques offer improved reproducibility, throughput, specificity, operability, and standardization. Here, we review recent progress in the systematic discovery of DMPCs using shotgun proteomics. Furthermore, the applications of shotgun proteomics supporting drug development, toxicity mechanism investigation, and drug repurposing processes are also reviewed and prospected.

Internal cavities in structural elements, such as in concrete-filled steel tubes (CFSTs) of arch ribs reduce confinement, bearing capacity, and the durability of the arch bridges. Formation of internal cavities may be either materials related, which affects proper consolidation, or construction related, especially in terms of proper timing and delivery of concrete slurry to horizontal and inclined structural members. Nondestructive test methods such as ultrasonics have been employed for detection of internal cavities. Despite their success, point-by-point inspection of structural members becomes time-consuming and inefficient, especially when entire structures need to be inspected. Infrared thermography (IR) provides a more reasonable global approach for detection of anomalies. The accuracy and resolution of IR depend on the local ambient conditions affecting convection and external thermal flux prior to detection by IR. The research described herein pertains to the development of a hybrid thermographic approach by using Brillouin fiber optic sensors (BFOSs) for direct detection of thermal convection at the surfaces of steel tubes. Accurate quantitative detection of internal cavity locations and their dimensions required development of a specific machine learning-based approach through which the distributed thermographic data was converted to a series of grayscale images. A Faster Region-based Convolutional Neural Network (Faster R-CNN) based on the improved VGG-16 (IVGG-16) network architecture was utilized for this purpose. The experimental work involved design and fabrication of a distributed temperature sensing sheet (DTSS) for simultaneous transmission of thermal energy into CFST specimens and acquisition of distributed thermographic data by the BFOS. By using the proposed approach, it was possible to detect the embedded internal cavities during the experiments.

In the composite structure of a concrete-filled steel tube (CFST), because the concrete is concealed inside the steel tube, subsurface cavities can occur and are difficult to identify. In this study, a thermal-driven method based on Brillouin fiber-optic sensors (BFOSs) was proposed to quantitatively identify subsurface cavities in CFSTs. By performing a thermodynamic analysis of subsurface cavities in CFSTs, a thermal model related to the relationship between the subsurface cavity size and the temperature rise at the top surface of the CFST was established for the first time. Then, a sensing scheme based on the BFOS was proposed, and its feasibility was evaluated through an experimental program. The experimental program involved the use of an active heating layer for inputting heat flow into the CFST structure and BFOSs for the distributed measurement of temperature to identify subsurface cavities in CFSTs. The experimental results indicated that the BFOSs can achieve real-time distributed measurements of the surface temperature of the CFSTs. According to the temperature anomalies in the temperature rise curves of the CFSTs, the subsurface cavities can be accurately located in the longitudinal direction of the CFST, and its length can be quantified. There is an obvious linear relationship between the temperature rise and the square root of the heating time, from which the equivalent heat absorption coefficient (EHAC) can be determined. Furthermore, according to the relationship between the subsurface cavity height and the EHAC in the thermodynamic theoretical analysis, the subsurface cavity height can be obtained quantitatively.

Covalent drugs are newly developed and proved to be successful therapies in past decades. However, the pharmacokinetics (PK) and pharmacodynamic (PD) studies of covalent drugs now ignore the drug and metabolite-protein modification. The low abundance of modified proteins also prevents its investigation. Herein, a simple, selective, and sensitive liquid chromatography-mass spectrometry (LC-MS)/MS quantitative method was established based on the mechanism of a drug and its metabolite-protein adducts using osimertinib as an example. Five metabolites with covalent modification potential were identified. The drug and its metabolite-cysteine adducts released from modified proteins by a mixed hydrolysis method were developed to characterize the level of the modified proteins. This turned the quantitative objects from proteins or peptides to small molecules, which increased the sensitivity and throughput of the quantitative approach. Accumulation of protein adducts formed by osimertinib and its metabolites in target organs was observed in vivo and long-lasting modifications were noted. These results interpreted the long duration of the covalent drugs' effect from the perspective of both parent and the metabolites. In addition, the established method could also be applied in blood testing as noninvasive monitoring. This newly developed approach showed great feasibility for PK and PD studies of covalent drugs.

To compensate for the shortcomings of the existing point detection methods for grouting defects in prestressed tendon ducts, such as low detection efficiency, stringent detection environment, and easy omission of grouting defects, this article presents a distributed detection approach to detect the grouting defects in tendon ducts. The main objective of the research pertained to the development of a method for accurate identification and location of grouting defects and qualitative evaluation of the size of grouting defects using distributed fiber optic sensors with active heating. Using the thermal analysis of grouting defects in the tendon duct and the research on distributed fiber optic sensors measurement characteristics, our work proposed a method for identifying and locating grouting defects and explored the effect of the grouting defect length and the grouting compactness on the temperature rise of distributed fiber optic sensors. The feasibility of the proposed approach is evaluated through an experimental program. The experimental program involved use of heating distributed fiber optic sensors for the distributed measurement of temperature after the heating and detection of grouting defects in tendon ducts in a concrete beam. The results indicate that distributed fiber optic sensors can monitor the temperature distribution of the tendon duct during a temperature rise in real time. Grouting defects in the tendon duct can be quickly detected and located by identifying temperature anomalies in the temperature contour of the distributed fiber optic sensors. Furthermore, there is a linear relationship between the defect length and the abnormal temperature length on the distributed fiber optic sensors, and the defect length can be identified based on the abnormal temperature length obtained by the measurement. Plane-equivalent thermal conductivity can be used to evaluate the grouting compactness of the tendon duct. When the grouting compactness is greater than 70%, the smaller the plane-equivalent thermal conductivity is, the lower the grouting compactness is. The plane-equivalent thermal conductivity is basically the same when the grouting compactness is less than 70%.

Hepatitis E virus (HEV) is the major pathogen of viral hepatitis. However, the understanding of the HEV life cycle is limited. In the present study, cells were separately infected with non-enveloped HEV (derived from feces or bile) or quasi-enveloped HEV (derived from the cell culture after serial passages, eHEV) and observed by confocal fluorescence microscopy to investigate the life cycle of HEV. HEV finished its binding and entry into host cells at first 6 h post-inoculation (hpi). Cells inoculated with eHEV showed less infectivity than cells inoculated with non-enveloped HEV. Newly synthesized progeny virions were released into the supernatant of cell cultures from 48 hpi. qRT-PCR and Western blotting results showed that the supernatant's progeny viruses were infectious even after 5 serial passages. These results show the significant difference between non-enveloped HEV and eHEV, which will provide novel insights into the HEV replication cycle. The efficient cell culture of HEV will promote the development of anti-HEV drugs and vaccines. This article is protected by copyright. All rights reserved.

When simulating large rotation, the false volume expansion and elastic distortion problems of the block occurs severely in the original discontinuous deformation analysis (DDA). In this st...

Hepatitis E virus (HEV) infection has become a global concern with high mortality rates among pregnant women, especially those in their third trimester of pregnancy. Estrogen plays an important role in mediating the body, regulating physiological and pathological processes. Estrogen is activated by binding to estrogen receptors (ERs) and mediates rapid signaling events by pathways that involve transmembrane ERs. Our previous study had confirmed that high estrogen levels during pregnancy are associated with high HEV titers. However, the association between HEV infection and estrogen signaling pathways remains unclear. In the present study, the regulation of estrogen signaling pathways by HEV infection was evaluated. Results demonstrated that HEV infection significantly inhibits the cAMP-PKA-CREB and PI3K-AKT-mTOR signaling pathways, but is independent of the Ras-Raf-MEK-ERK signaling pathway. In summary, the increasing estrogen levels and highly activated ERα during pregnancy aggravates HEV replication. The exacerbation of HEV replication, in turn, inhibits ERα expression and suppresses both cAMP-PKA-CREB and PI3K-AKT-mTOR signaling pathways.

The analysis of coupled thermo-hydro-mechanical behaviors of porous media is the research focus in diverse areas. In this study, fully coupled symmetric governing equations for thermo-hydr...

Probiotics can release many bioactive peptides that confer a myriad of benefits to the host health. However, exploring new bioactive peptides secreted by probiotics is hampered by lots of matrix-related interference peptides from the medium, and the low abundance. To this end, a new approach integrating mixed-mode cationic exchange based solid-phase extraction (MCX-SPE) coupled with liquid chromatography-mass spectrometry (LC–MS) and feature-based molecular networking (FBMN) was developed. FBMN's intuitive visualization results enabled twenty-five novel peptides to be quickly discovered and characterized from the cultures of three strains of Bifidobacterium, B. animalis, B. longum, and B. pseudolongum. Interestingly, four were uniquely secreted by B. animalis treated with gypenosides, and one showed ACE inhibitory effect with an IC50 value of 193.22 μM. Consequently, this approach could serve as a powerful tool for quickly discovering bioactive peptides from the complex metabolites of probiotics, which contributes to the development of functional foods and nutraceuticals.

In this study, Discontinuous Deformation Analysis (DDA) method is extended to simulate Soil-Water Characteristic Curve (SWCC) by considering both capillary water and bound water at the micro-scale. First, a simple and practical bound water model is proposed and incorporated into DDA program to simulate SWCC in the high suction range. Then, to prove the availability of the developed program, the extended DDA is used to simulate the SWCCs of two types of fine sand with kaolin clay in a wide suction range. The simulation results agree with the experimental results, which demonstrate that the extended DDA is an alternative method for simulating and analyzing SWCC of both cohesionless soil and cohesive soil. Finally, one of the influential factors specific surface area is theoretically analyzed. This study provides an approach to simulate the matric suction of unsaturated soil, and the extended DDA could be a potential tool for unsaturated soil research.

Drug-induced liver injury (DILI) is a major side effect, sometimes can't be exactly evaluated by current approaches partly as the covalent modification of drug or its reactive metabolites (RMs) with proteins is a possible reason. In this study, we developed a rapid, sensitive, and specific analytical method to assess the hepatotoxicity induced by drug covalently modified proteins based on the quantification of the modified amino acids using toosendanin (TSN), a hepatotoxic chemical, as an example. TSN RM-protein adducts both in rat liver and blood showed good correlation with the severity of hepatotoxicity. Thus, TSN RM-protein adducts in serum can potentially serve as minimally invasive biomarkers of hepatotoxicity. Meanwhile, large-scale chemical proteomics analysis showed that at least 84 proteins were modified by TSN RMs in rat liver, and the bioinformatics analysis revealed that TSN might induce hepatotoxicity through multi-target protein-protein interaction especially involved in energy metabolism. These findings suggest that our approach may serve as a valuable tool to evaluate DILI and investigate the possible mechanism, especially for complex compounds.

Rainfall-induced landslide is a common natural hazard, and one of the disaster-causing factors is the loss of apparent cohesion that is mainly caused by the dissipation of matric suction. To analyze the rainfall-induced landslide, especially the post-failure behaviors, a matric suction model is proposed and incorporated into the Discontinuous Deformation Analysis (DDA). In this model, the matric suction is simplified as an equivalent line load and updated at each time step. The safety factor of the simple sliding model simulated by the extended DDA (DDA_c) showed a good agreement with the limit equilibrium method. The simulated relationship between runout distance and the degree of saturation of the multi-block sliding model was validated by the experimental results. Finally, a rainfall-induced landslide in Fukuchi-machi was simulated using the extended DDA. The results illustrated that the apparent cohesion loss is an important mechanism for landslide initiation and a crucial reason for the long-runout distance. The presented DDA_c can be served as a qualified tool to analyze shallow slope stability and post-failure behavior involving apparent cohesion.

This paper presents an integrated numerical algorithm based on the nonlinear augmented finite element method (N-AFEM) to accurately simulate the arbitrary evolving strong discontinuities (cracks/slip lines) and failure behaviors in geotechnical structures. A novel nonlinear elemental augmentation and condensation scheme was first proposed within the N-AFEM framework, which allows the consideration of nonlinear coupled intra-element cracks without the need of additional nodes or nodal DoFs. Then a modified exponential cohesive zone model (CZM) that considers the coupling effects between tension/compression and shear at the fracture surface was proposed to describe the fracture process of geomaterials. Besides, a nonlinear yielding function based on the Mohr-Coulomb strength theory was introduced into the framework and serves as the fracture initiation criteria for geomaterials. Finally, several benchmark examples were simulated and the predicted results were compared with existing numerical or experimental data to demonstrate the validity of the proposed method.

This paper presents an improved treatment for those advanced FEMs that use stresses in the crack-tip element for evaluation crack propagation condition. We show that the common treatment of obtaining crack-tip displacements using simple interpolation from the edge of the crack-tip element is inaccurate and is responsible for the jagged jump and unwarping behavior (JJU) frequently reported in literature. In this study we propose a more accurate treatment by introducing an element node with independent degree of freedom (DoF) to enrich the crack-tip element. We show that the proposed approach can relieve the stiffness overestimation of the crack-tip element without disrupting the standard element interpolation process. Results of numerical examples demonstrate that the improved treatment can greatly improve the stress shielding phenomenon and effectively reduce the JJU in load-displacement curves.

Salidroside (Sal) is a traditional Chinese medicine with various pharmacological effects. The present study aimed to investigate the protective effect of Sal on ethanol-induced acute gastric ulcer and H2O2-induced gastric epithelial cell damage. 0.2 ml ethanol and 400 μM H2O2 were applied to establish a gastric ulcer model in vivo and in vitro respectively. The production of interleukin (IL)-6, interleukin (IL)-1β and tumor necrosis factor (TNF)-α was analyzed, as well as myeloperoxidase (MPO), malondialdehyde (MDA) and superoxide dismutase (SOD). MTT assay was used to detect cell viability. In addition, MAPK/NF-κB signal pathway-related proteins p-ERK, p-JNK, p-p38, p-IκBα and p-NF-κBp65 were analyzed to determine the underlying protective mechanism. Downstream genes such as cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX) and leukotrienes B4 (LTB4) were also measured. Obtained data indicated that Sal inhibited the overproduction of pro-inflammatory cytokines and enhanced antioxidant activity. Collectively, it is assumed that Sal could alleviate ethanol-induced acute gastric ulcer and H2O2-induced gastric epithelial cell damage through the MAPK/NF-κB pathway.

Evodiamine (EVD), a major alkaloid compound extracted from the dry unripened fruit Evodia fructus (Evodia rutaecarpa Benth., Rutaceae), has various pharmacological effects. The purpose of the present study was to investigate the possible anti-ulcerogenic potential of EVD and explore the underlying mechanism against ethanol-induced gastric ulcer in mice. Administration of EVD at the doses of 20, 40mg/kg body weight prior to the ethanol ingestion could effectively protect the stomach from ulceration. The gastric lesion was significantly ameliorated in the EVD group compared with that in the model group. Pre-treatment with EVD prevented the oxidative damage and decreased the levels of prostaglandin E2 (PGE2) content, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). In addition, EVD pretreatment markedly increased the serum levels of glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT), decreased malonaldehyde (MDA) content in serum and activity of myeloperoxidase (MPO) in stomach tissues compared with those in the model group. In the mechanistic study, significant elevation of Rho, Rho-kinase 1 (ROCK1), ROCK2, cytosolic and nucleic NF-κBp65 expressions were observed in the gastric mucosa group, whereas EVD effectively suppressed the protein expressions of Rho, Rho-kinase 1 (ROCK1), ROCK2, cytosolic and nucleic NF-κBp65 in mice. Moreover, EVD showed protective activity on ethanol-induced GES-1 cells, while the therapeutic effects were not due to its cytotoxity. Taken together, these results strongly indicated that EVD exerted a gastro-protective effect against gastric ulceration. The underlying mechanism might be associated with the improvement of antioxidant and anti-inflammatory status through Rho/NF-κB pathway.