The evolutionary features and internal logic of the one-vote veto system: A Nvivo analysis based on the policy texts of the three provinces in the east, middle and west.

Analyzing the evolutionary features and internal logic of the one-vote veto system in China over the past two decades is highly significant when considering reform and standardization. In order to conduct this analysis, the Nvivo 12 software was used to examine policy texts related to the one-vote veto issued by Fujian, Hubei, and Gansu provinces. Through a comparative analysis of keyword frequency statistics, policy text form, and content characteristics across the three provinces, it was discovered that governmental departments have experienced fundamental changes in their utilization of the one-vote veto system after 20 years of development. These changes are primarily seen in the refinement of the description of the one-vote veto in policy texts, the gradual reduction in the withdrawal mechanism of the one-vote veto, and an expanded application field for the one-vote veto.

Prognosis for local radical treatment in patients with esophageal squamous cell carcinoma with low-risk oligometastatic recurrence after curative resection: a retrospective cohort study.

Background: Patients with esophageal carcinoma (EC) with recurrent disease have a poor prognosis. A limited numbers of metastases, safely treatable with curative intent, diagnosed after curative esophagectomy may be defined as oligometastatic recurrence (OLR). However, the appropriate number of metastases and metastatic organs involved remains incompletely characterized. And the role of local therapy in OLR after radical esophagectomy remains unknown. Therefore, this study aimed to more accurately define low-risk OLR in patients with esophageal squamous cell carcinoma (ESCC) treated with radical resection and investigate the role of chemotherapy combined with local treatment (CCLT) in these patients. Methods: A total of 83 sequential patients with ESCC who underwent radical esophagectomy, with an Eastern Cooperative Oncology Group (ECOG) performance status ≤2, with ability to tolerate chemotherapy (CT) and local treatment, and with newly diagnosed recurrence between January 2010 and May 2019 in our hospital were recruited. Overall survival (OS) curves after recurrence were analyzed using the Kaplan-Meier method, and a log-rank test was used to assess the OS differences. Cox proportional hazards regression analysis was performed to identify independent factors associated with 2-year OS. Regular follow-up examinations were assessed by thoracic and upper abdominal computed tomography (CT) scanning every 3 months in the first year, every 6 months over the next 2 years, and yearly thereafter. Results: Of the 83 patients with ESCC (71 males and 12 females), the median age was 56 years (range, 37-79 years). Thirty-five patients with ESCC with ≤5 metastases safely treatable with curative intent located in a single organ had a favorable OS compared to 48 patients with metastases located in 2-3 organs with or without regional recurrence and/or regional lymph node (LN) metastases. In our study, low-risk OLR was defined as the presence of ≤5 metastases safely treatable with curative intent in a single organ and was compared to patients with 2-3 organs involved. The 2-year OS of patients with low-risk OLR with liver oligometastases was significantly worse than survival in patients with lung oligometastases (0% vs. 61.1%, P=0.009). Patients with ESCC in the low-risk OLR group treated with CCLT had a better 2-year OS after recurrence than those who received CT alone (66.7% vs. 30.4%, P=0.003). The multivariable Cox regression model identified treatment method [hazard ratio (HR) 3.920, P=0.02] as an independent factor affecting OS after recurrence for low-risk OLR. Conclusions: Low-risk OLR was defined as ≤5 metastases safely treatable with curative intent in a single organ. Patients with ESCC with low-risk OLR after curative resection treated with CCLT have a favorable OS compared to those treated with CT alone. CCLT is a promising treatment option for patients with ESCC and low-risk OLR.

A crystalline stannyne.

The synthesis of heteronuclear alkyne analogues incorporating heavier group 14 elements (R1-C≡E-R2, E = Si, Ge, Sn, Pb) has posed a long-standing challenge. Neutral silynes (R1-C≡Si(L)-R2) and germynes (R1-C≡Ge(L)-R2) stabilized by a Lewis base have achieved sufficient stability for structural characterization at low temperatures. Here we show the isolation of a base-free stannyne (R1-C≡Sn-R2) at room temperature, achieved through the strategic use of a bulky cyclic phosphino ligand in combination with a bulky terphenyl substituent. Despite an allenic structure with strong delocalization of π-electrons, this compound exhibits adjacent ambiphilic carbon and tin centres, forming a carbon-tin multiple bond with ionic character. The stannyne demonstrates reactivity similar to carbenes or stannylenes, reacting with 1-adamantyl isocyanide and 2,3-dimethyl-1,3-butadiene. Additionally, its carbon-tin bond can be saturated by Et3N·HCl or cleaved by isopropyl isocyanate.

Final analysis of camrelizumab plus chemotherapy for untreated advanced or metastatic esophageal squamous cell carcinoma: The ESCORT-1st trial.

BACKGROUND: The interim analysis of the randomized phase 3 ESCORT-1st study demonstrated significantly longer overall survival (OS) and progression-free survival (PFS) for camrelizumab-chemotherapy than placebo-chemotherapy in untreated advanced/metastatic esophageal squamous cell carcinoma (ESCC). Here, we present the final analysis of this study and investigate potential indicators associated with OS. METHODS: Patients were randomized 1:1 to receive camrelizumab (200 mg) or placebo, both in combination with up to six cycles of paclitaxel (175 mg/m2) and cisplatin (75 mg/m2). All treatments were administered intravenously every 3 weeks. The co-primary endpoints were OS and PFS assessed by the independent review committee. FINDINGS: As of April 30, 2022, the median OS was significantly longer in the camrelizumab-chemotherapy group compared to the placebo-chemotherapy group (15.6 [95% confidence interval (CI): 14.0-18.4] vs. 12.6 months [95% CI 11.2-13.8]; hazard ratio [HR]: 0.70 [95% CI 0.58-0.84]; one-sided p < 0.0001), with 3-year OS rates of 25.6% and 12.8% in the two groups, respectively. The 2-year PFS rates were 20.4% in the camrelizumab-chemotherapy group and 3.4% in the placebo-chemotherapy group. Adverse events were consistent with those reported in the interim analysis. Higher PD-L1 expression correlated with extended OS, and multivariate analysis identified sex and prior history of radiotherapy as independent indicators of OS. CONCLUSIONS: The sustained and significant improvement in efficacy with camrelizumab-chemotherapy compared to placebo-chemotherapy, along with the absence of accumulating or delayed toxicities, supports the long-term use of camrelizumab-chemotherapy as a standard therapy in untreated advanced/metastatic ESCC. FUNDING: This study was funded by Jiangsu Hengrui Pharmaceuticals Co., Ltd.

Carbene-Stabilized Phosphagermylenylidene: A Heavier Analog of Isonitrile.

Phosphagermylenylidenes (R-P═Ge), as heavier analogs of isonitriles, whether in their free state or as complexes with a Lewis base, have not been previously identified as isolable entities. In this study, we report the synthesis of a stable monomeric phosphagermylenylidene within the coordination sphere of a Lewis base under ambient conditions. This species was synthesized by Lewis base-induced dedimerization of a cyclic phosphagermylenylidene dimer or via Me3SiCl elimination from a phosphinochlorogermylene framework. The deliberate integration of a bulky, electropositive N-heterocyclic boryl group at the phosphorus site, combined with coordination stabilization by a cyclic (alkyl)(amino)carbene at the low-valent germanium site, effectively mitigated its natural tendency toward oligomerization. Structural analyses and theoretical calculations have demonstrated that this unprecedented species features a P═Ge double bond, characterized by conventional electron-sharing π and σ bonds, complemented by lone pairs at both the phosphorus and germanium atoms. Preliminary reactivity studies show that this base-stabilized phosphagermylenylidene demonstrates facile release of ligands at the Ge atom, coordination to silver through the lone pair on P, and versatile reactivity including both (cyclo)addition and cleavage of the P═Ge double bond.

Mitochondrial ribosomal protein S24 is associated with immunosuppressive microenvironment and cold tumor in lung adenocarcinoma.

Objective: MRPS24 (Mitochondrial Ribosomal Protein S24) belongs to the mitochondrial ribosomal protein family, which participates in the protein synthesis of the mitochondrion. However, the relationship of MRPS24 with lung adenocarcinoma (LUAD) remained unknown. We aimed to identify its immunological and functional mechanisms in LUAD. Methods: The analysis of MRPS24 expression, clinical features, diagnosis, prognosis, function analysis, genetic alteration, copy number variations, methylation, and tumor microenvironment was investigated by the TCGA, UCSC Xena, GEO, HPA, GEPIA, cBioPortal, MethSurv, TIMER, TIMER2.0, and TISIDB databases. Results: MRPS24 was found to be more abundant in LUAD tumor tissue than in normal tissue. High levels of MRPS24 expression were found to be an independent prognostic factor by multivariate analysis. Functional analysis revealed that MRPS24 expression was associated with the immune, cell cycle and methylation. MRPS24 methylation level was inversely linked with its expression (p < 0.001). Patients with low MRPS24 methylation had a worse prognosis than those with high methylation (p < 0.05). In addition, the result revealed that the MRPS24 expression was inversely linked to the immune cell infiltration in LUAD. Finally, the validations of the expression level, prognosis, and immune cell infiltration of MRPS24 were in accordance with our previous results. Conclusions: This study systematically explored that MRPS24 expression was significantly correlated with prognosis, tumorigenesis, genetic alteration, copy number variations, methylation, and immune cell infiltration in LUAD. MRPS24 might be a potential immune-related biomarker in the development and treatment of LUAD, thereby acting as a promising predictor of immunotherapy response in LUAD.

CloudProteoAnalyzer: scalable processing of big data from proteomics using cloud computing.

Summary: Shotgun proteomics is widely used in many system biology studies to determine the global protein expression profiles of tissues, cultures, and microbiomes. Many non-distributed computer algorithms have been developed for users to process proteomics data on their local computers. However, the amount of data acquired in a typical proteomics study has grown rapidly in recent years, owing to the increasing throughput of mass spectrometry and the expanding scale of study designs. This presents a big data challenge for researchers to process proteomics data in a timely manner. To overcome this challenge, we developed a cloud-based parallel computing application to offer end-to-end proteomics data analysis software as a service (SaaS). A web interface was provided to users to upload mass spectrometry-based proteomics data, configure parameters, submit jobs, and monitor job status. The data processing was distributed across multiple nodes in a supercomputer to achieve scalability for large datasets. Our study demonstrated SaaS for proteomics as a viable solution for the community to scale up the data processing using cloud computing. Availability and implementation: This application is available online at https://sipros.oscer.ou.edu/ or https://sipros.unt.edu for free use. The source code is available at https://github.com/Biocomputing-Research-Group/CloudProteoAnalyzer under the GPL version 3.0 license.

Fine structure of the compound eyes of the crepuscular moth Grapholita molesta (Busck 1916) (Lepidoptera: Tortricidae).

Morphological organization, ultrastructure and adaptational changes under different light intensities (10000, 100, 1, and 0.01 mW/m2) of the compound eye of the oriental fruit moth Grapholita molesta (Busck 1916) were investigated. Its superposition type of eyes consist of approximately 1072 ommatidia in males and 1029 ommatidia in females with ommatidial diameters of around 15 µm. Each ommatidium features a laminated corneal lens densely covered by corneal nipples of 256 nm in height. Crystalline cones are formed by four cone cells, proximally tapering to form a narrow crystalline tract with a diameter of 1.5 µm. Eight retinula cells, two primary and six secondary pigment cells per ommatidium are present. The 62.3 µm long rhabdom is divided into a thin 1.8 µm wide distal and a 5.2 µm wide proximal region. Distally the fused rhabdom consists of the rhabdomeres of seven retinula cells (R1-R7) and connects with the crystalline cone. In the proximal rhabdom region, the pigment-containing retinula cell R8 occupies a position in centre of the rhabdom while R1-R7 cells have taken peripheral positions. At this level each ommatidial group of retinula cells is surrounded by a tracheal tapetum. In response to changes from bright-light to dim-light adaptations, the pigment granules in the secondary pigment cells and retinula cells migrate distally, with a decrease in the length of crystalline tract.

A stable rhodium-coordinated carbene with a σ0π2 electronic configuration.

Isolable singlet carbenes have universally adopted a σ2π0 electronic state, making them σ-donors and π-acceptors. We present a rhodium-coordinated, cationic cyclic diphosphinocarbene with a σ0π2 ground state configuration. Nuclear magnetic resonance spectroscopy studies show a carbene carbon chemical shift below -30.0 parts per million. X-ray crystallography reveals a planar RhP2C configuration. Quantum chemical calculations rationalize how σ-electron delocalization/donation and π-electron negative hyperconjugation together stabilize the formally vacant σ orbital and the filled π orbital at the carbene center. In contrast to traditional carbene counterparts this carbene can undergo synthetic transformations with both a Lewis base and a silver salt, producing a Lewis acid/base adduct and a silver π-complex, respectively. Exhibiting ambiphilic reactivity, it can also form a ketenimine through reaction with an isocyanide.

Optical time domain reflectometry based on a self-chaotic circular-sided microcavity laser.

A self-chaotic circular-sided square microcavity laser, with a chaos bandwidth of 12.9 GHz and a flatness of ±3d B, was applied in optical time domain reflectometry (OTDR). Using the broadband chaos laser, we demonstrated a range resolution of 4.5 mm and a 25-km detection distance experimentally. The solitary wide-bandwidth microcavity chaos laser, without the extra correlation peaks in optical feedback chaotic lasers, has shown potential advantages for correlation OTDR in practical application.

CIRC_0033530 KNOCKDOWN ALLEVIATES LIPOPOLYSACCHARIDE-INDUCED ACUTE LUNG INJURY MODEL OF HUMAN LUNG FIBROBLASTS BY MIR-1184/TLR4 AXIS.

ABSTRACT: Background: Circular RNAs have been reported to be involved in regulating the progression of sepsis and sepsis-associated damage. Herein, this work investigated whether circ_0033530 had roles in the process of septic acute lung injury (sepsis-ALI) and its associated mechanism. Methods: Lipopolysaccharide (LPS)-stimulated human lung fibroblasts MRC-5 were used to mimic the cell model of sepsis-ALI in vitro . Levels of genes and proteins were detected by quantitative real-time polymerase chain reaction and Western blotting. Functional experiments were conducted using 5-ethynyl-2'-deoxyuridine assay, Cell Counting Kit-8 assay, flow cytometry, and enzyme-linked immunosorbent assay. The interaction between miR-1184 and circ_0033530 or toll-like receptor 4 (TLR4) was confirmed by dual-luciferase reporter and RNA immunoprecipitation assays. Results: Circ_0033530 expression was lower in sepsis patients and LPS-induced fibroblasts than those in healthy control and untreated cells. Functionally, knockdown of circ_0033530 protected fibroblasts against LPS-induced proliferation arrest, apoptosis, and inflammatory response. Mechanistically, circ_0033530 acted as a sponge for miR-1184, and TLR4 RNA was targeted by miR-1184, indicating the circ_0033530/miR-1184/TLR4 axis. Further rescue experiments showed that circ_0033530 silencing-mediated growth inhibition and inflammation on fibroblasts were attenuated by miR-1184 downregulation or TLR4 upregulation. Conclusion: Circ_0033530 knockdown alleviated LPS-induced proliferation arrest, apoptosis, and inflammation in lung fibroblasts by miR-1184/TLR4 axis, and provided molecular theoretical basis for circ_0033530 on the pathogenesis of sepsis-ALI.

Alkylation and Arylation at Boron in NHC-Stabilized Phosphaborenes.

Phosphaborenes, featuring a phosphorus-boron multiple bond, remain a relatively untapped area in chemical research due to the limited synthetic methods. Introducing leaving groups as substituents to the phosphorus or boron can pave the way for enhanced functionalization and modification. In this study, we present the synthesis of phosphaborenes featuring an N-heterocyclic boryl group on phosphorus and halogen substituent on boron, with stabilization provided by an N-heterocyclic carbene. Straightforward alkylation/arylation of these phosphaborenes is achieved by substituting the halogen with benzyl and aryl groups at the boron terminus. Our approach offers an efficient route to produce a diverse array of phosphaborene structures.

Hypoxia-induced factor-1α promotes radioresistance of esophageal cancer cells by transcriptionally activating LINC01116 and suppressing miR-3612 under hypoxia.

Esophageal cancer (EC) is a challenging tumor to treat with radiotherapy, often exhibiting resistance to this treatment modality. To explore the factors influencing radioresistance, we focused on the role of hypoxia-induced factor-1α (HIF-1α), and its interaction with the long noncoding RNA long intergenic nonprotein coding RNA 1116 (LINC01116). We analyzed the LINC01116 expression in EC and EC cell lines/human normal esophageal epithelial cell line (Het-1A). LINC01116 was silenced/overexpressed in EC109/KYSE30 cells under hypoxia, followed by radioresistance assessment. We measured HIF-1α levels in hypoxic EC cells and further validated the binding of HIF-1α with LINC01116, analyzing their interaction in EC cells. We then performed experiments in EC109 cells by transfection them with sh-HIF-1α/oe-LINC01116 to verify the effects. Additonally, we analyzed the localization of LINC01116 and its binding with miR-3612, followed by a combined experiment performed to validate the results. Our findings indicated that LINC01116 was highly expressed in EC and further elevated in hypoxic EC cells. LINC01116 was expressed at a high level in EC, which was further elevated in EC cells under hypoxic conditions. Knockdown of LINC01116 triggered EC cell apoptosis, thus suppressing radioresistance. Further investigation revealed that HIF-1α transcriptionally activated LINC01116 expression under hypoxia, and silencing HIF-1α lowered EC cell radioresistance by downregulating LINC01116. Under hypoxic conditions, LINC01116 could function as a sponge for miR-3612 and inhibit its expression. This interaction between LINC01116 and miR-3612 played a crucial role in mediating radioresistance in EC cells. Briefly, under hypoxic conditions, HIF-1α facilitates radioresistance of EC cells by transcriptionally activating LINC01116 expression and downregulating miR-3612.

Feedback insensitivity in a self-chaotic microcavity laser.

Insensitivity to external optical feedback is experimentally demonstrated in a self-chaotic deformed square microcavity laser for the first time, to the best of our knowledge. Both the optical and radio frequency (RF) spectra of the microlaser remain unaffected for external optical feedback with feedback strength as high as 9.9 dB. In addition, the autocorrelation function curve exhibits no time-delayed peaks. The insensitivity makes the self-chaotic microcavity laser promising for applications in feedback-insensitive optical sources.

Preoperative inflammation and nutrition-based comprehensive biomarker for predicting prognosis in resectable colorectal cancer.

Background: Colorectal cancer (CRC) remains a major global health concern, with significant morbidity and mortality rates. In this study, we aimed to develop a comprehensive blood indicator based on systemic inflammation and nutritional condition to predict the prognosis of resectable CRC patients. Methods: A retrospective cohort of 210 CRC patients who underwent radical resection at the First Affiliated Hospital of Chongqing Medical University, China, between January 2015 and December 2017, was included in the analysis. Baseline characteristics, preoperative blood markers, including neutrophil count, monocyte count, lymphocyte count, platelets, albumin, and CEA were retrospectively reviewed. Various blood indicators, such as NLR, PLR, MLR, SIRI and OPNI were calculated. The least absolute shrinkage and selection operator (LASSO) method was employed to select indicators to establish a novel comprehensive biomarker (named PSI). Kaplan-Meier survival curves and log-rank tests were used to evaluate the prognostic impact of preoperative OPNI, SIRI, and PSI. Univariate and multivariate Cox regression model were conducted to identify independent prognostic factors for CRC. The receiver operating characteristic (ROC) method assessed the predictive ability of PSI, stage, OPNI, and SIRI. Results: Patients with higher preoperative OPNI and lower SIRI values had significantly better overall survival (OS). PSI was identified as an independent prognostic factor for OS in both univariate and multivariate analysis. Patients with medium (28.3-43.4) and high (>43.4) PSI scores exhibited superior OS compared to those with low (≤ 28.3) PSI scores. PSI showed higher predictive ability (AUC: 0.734) than individual indicators alone (OPNI: 0.721, SIRI: 0.645, stage: 0.635). Conclusion: The novel indicator, PSI, based on preoperative SIRI and OPNI, demonstrated significant prognostic value for resectable CRC patients. PSI outperformed individual indicators and could serve as a reliable tool for prognostic evaluation in CRC patients.

Development of a combined model incorporating clinical characteristics and magnetic resonance imaging features to enhance the predictive value of a prognostic model for locally advanced cervical cancer.

Objective: This study aimed to develop non-invasive predictive tools based on clinical characteristics and magnetic resonance imaging (MRI) features to predict survival in patients with locally advanced cervical cancer (LACC), thereby facilitating clinical decision-making. Methods: We conducted a retrospective analysis of clinical and MRI data from LACC patients who underwent radical radiotherapy at our center between September 2012 and May 2020. Prognostic predictors were identified using single-factor and multifactor Cox analyses. Clinical and MRI models were established based on relevant features, and combined models were created by incorporating MRI factors into the clinical model. The predictive performance of the models was evaluated using the area under the curve (AUC), consistency index (C-index), and decision curve analysis (DCA). Results: The study included 175 LACC patients. Multivariate Cox analysis revealed that patients with FIGO IIA-IIB stage, ECOG score 0-1, CYFRA 21-1<7.7 ng/ml, ADC ≥ 0.79 mm^2/s, and Kep ≥ 4.23 minutes had a more favorable survival prognosis. The clinical models, incorporating ECOG, FIGO staging, and CYFRA21-1, outperformed individual prognostic factors in predicting 5-year overall survival (AUC: 0.803) and 5-year progression-free survival (AUC: 0.807). The addition of MRI factors to the clinical model (AUC: 0.803 for 5-year overall survival) increased the AUC of the combined model to 0.858 (P=0.011). Similarly, the combined model demonstrated a superior predictive ability for 5-year progression-free survival, with an AUC of 0.849, compared to the clinical model (AUC: 0.807) and the MRI model (AUC: 0.673). Furthermore, the C-index of the clinical models for overall survival and progression-free survival were 0.763 and 0.800, respectively. Upon incorporating MRI factors, the C-index of the combined model increased to 0.826 for overall survival and 0.843 for progression-free survival. The DCA further supported the superior prognostic performance of the combined model. Conclusion: Our findings indicate that ECOG, FIGO staging, and CYFRA21-1 in clinical characteristics, as well as ADC and Kep values in MRI features, are independent prognostic factors for LACC patients undergoing radical radiotherapy. The combined models provide enhanced predictive ability in assessing the risk of patient mortality and disease progression.

Prognostic value of Hematoxylin and eosin staining tumor-infiltrating lymphocytes (H&E-TILs) in patients with esophageal squamous cell carcinoma treated with chemoradiotherapy.

BACKGROUND: Tumor-infiltrating lymphocytes (TILs) by routine hematoxylin and eosin staining (H&E-TILs) are a robust prognostic biomarker in various cancers. However, the role of H&E-TILs in esophageal squamous cell carcinoma (ESCC) treated with concurrent chemoradiotherapy (CCRT) has not been reported. The purpose of this study was to assess the prognostic value of H&E-TILs in ESCC treated with CCRT. METHODS: The clinical data of 160 patients with ESCC treated with CCRT in our center between Jan. 2014 and Dec. 2021 were collected and retrospectively reviewed, and propensity score matching (PSM) analyses were performed. The H&E-TILs sections before CCRT were reassessed by two experienced pathologists independently. The H&E-TILs sections were classified into a positive group (+, > 10%) and a negative group (-, ≤ 10%) using 10% as the cutoff. The effects of H&E-TILs on overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional recurrence-free survival (LRFS) were explored using the Kaplan‒Meier method, and the log-rank test was used to test the differences. Multivariable analysis was performed using the Cox proportion hazards model. RESULTS: The short-term response to CCRT and the OS (P < 0.001), DMFS (P = 0.001), and LRFS (P < 0.001) rates were significantly different between the H&E-TILs (+) and H&E-TILs (-) groups. Subgroup analysis showed that H&E-TILs(+) with CR + PR group had a longer survival than H&E-TILs(-) with CR + PR, H&E-TILs(+) with SD + PD and H&E-TILs(-) with SD + PD group, respectively(P < 0.001). Furthermore, based on TCGA data, patients in the high TILs group had a better prognosis than those in the low TILs group. Multivariate analyses indicated that H&E-TILs and the short-term response to CCRT were the only two independent factors affecting OS, PFS, DMFS, and LRFS simultaneously, and H&E-TILs expression was associated with an even better prognosis for those patients with CR + PR. CONCLUSIONS: H&E-TILs may be an effective and beneficial prognostic biomarker for ESCC patients treated with CCRT. Patients with H&E-TILs (+) with PR + CR would achieve excellent survival. Further prospective studies are required to validate the conclusions.

One-Step Platform for Maduramicin and Salinomycin Detection Based on Bispecific Monoclonal Antibody and Interpretation of Molecular Recognition Mechanism.

Maduramicin (MAD) and salinomycin (SAL) are the widely used poly(ether ionophore) antibiotics to control coccidiosis in animals. Due to their strong cytotoxicity, strict control over their dosage and residue in animal food is necessary. To improve the detection efficiency of the existing single-residue detection methods, a tetraploid tumor hybrid system was constructed using drug mutagenesis, and the bispecific monoclonal antibody (BsMAb) against MAD and SAL was obtained by hybridization-hybridoma technology. By optimizing the optimal working concentration of the tracer and antibody, a multiresidue fluorescence polarization immunoassay method based on BsMAb was successfully established. The whole detection process takes 10 min, and the LOD values of MAD and SAL were 4.71 and 3.49 ng·g-1, respectively. IC50 values were 6.45 and 6.24 ng·mL-1, respectively. There was no cross-reactivity with other polyether ionophore antibiotics. Finally, a breakthrough in detection was achieved: bispecific monoclonal antibody prepared by the hybridization-hybridoma technology was used to detect maduramicin and salinomycin.

Structural insights into ligand recognition and selectivity of the human hydroxycarboxylic acid receptor HCAR2.

Hydroxycarboxylic acid receptor 2 (HCAR2) belongs to the family of class A G protein-coupled receptors with key roles in regulating lipolysis and free fatty acid formation in humans. It is deeply involved in many pathophysiological processes and serves as an attractive target for the treatment of cardiovascular, neoplastic, autoimmune, neurodegenerative, inflammatory, and metabolic diseases. Here, we report four cryo-EM structures of human HCAR2-Gi1 complexes with or without agonists, including the drugs niacin (2.69 Å) and acipimox (3.23 Å), the highly subtype-specific agonist MK-6892 (3.25 Å), and apo form (3.28 Å). Combined with molecular dynamics simulation and functional analysis, we have revealed the recognition mechanism of HCAR2 for different agonists and summarized the general pharmacophore features of HCAR2 agonists, which are based on three key residues R1113.36, S17945.52, and Y2847.43. Notably, the MK-6892-HCAR2 structure shows an extended binding pocket relative to other agonist-bound HCAR2 complexes. In addition, the key residues that determine the ligand selectivity between the HCAR2 and HCAR3 are also illuminated. Our findings provide structural insights into the ligand recognition, selectivity, activation, and G protein coupling mechanism of HCAR2, which shed light on the design of new HCAR2-targeting drugs for greater efficacy, higher selectivity, and fewer or no side effects.