PHYTOMEDICINE
·
2019
·
IF 4.18
Hongjin Chen,Yali Zhang,Wenxin Zhang,Hui Liu,Chuchu Sun,Bing Zhang,Bin Bai,Di Wu,Zhongxiang Xiao,Hazel Lum,Jianmin Zhou,Ruijie Chen,Guang Liang
Background ALI/ARDS is characterized by severe hypoxemic respiratory failure attributed to inflammatory tissue injury. There are no treatment modalities able to prevent/reverse the dire pathological sequelae in these patients . Evidence links the inflammatory lung injury to uncontrolled activation of the immune signaling complex, TLR4-MD2 (Toll-like receptor-myeloid differentiation factor 2). Baicalein , a natural flavonoid , is reported to have robust anti-inflammatory properties, but its inhibition mechanism remains unclear. Hypothesis/Purpose This study investigated the protective mechanisms of baicalein on ALI/ARDS. Methods We used two experimental mouse models of LPS-induced ALI , pulmonary infection model (intratracheal LPS), and systemic infection model (intravenous LPS). Blood, BALF , lung and liver tissues were analyzed using routine methods. In vitro studies using peritoneal mouse macrophages or recombinant proteins were designed to elucidate inhibition mechanisms of baicalein. Results Our critical new findings revealed that Baicalein was an MD2 inhibitor, directly bound to MD2, effectively suppressing TLR4-MD2 activation and the subsequent MAPK and NF-κB signaling. The inhibited MD2 prevented development of inflammatory tissue injury and improved survival. The importance of MD2 in the inflammatory injury in ALI was corroborated by data obtained from MD2 −/− mice, which did not develop the characteristic LPS-induced lung tissue damage. Thus, the findings indicated that MD2 was critical for development of ALI, functioning as an early upstream signal driving the progression of inflammatory injury. Conclusion Baicalein, as a direct and selective MD2 inhibitor, inhibited the early upstream TLR4-MD2 signaling and is a promising therapeutic agent for the treatment of ALI/ARDS.
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BRITISH JOURNAL OF PHARMACOLOGY
·
2017
·Vol. 175
·期 5
·840-854
·
IF 5.491
Yali Zhang,Tingting Xu,Zheer Pan,Xiangting Ge,Chuchu Sun,Chun Lu,Hongjin Chen,Zhongxiang Xiao,Bing Zhang,Yuanrong Dai,Guang Liang
Background and Purpose Acute lung injury (ALI) is a challenging clinical syndrome, which manifests as an acute inflammatory response. Myeloid differentiation protein 2 (MD2) has an important role in mediating LPS-induced inflammation. Currently, there are no effective molecular-based therapies for ALI or viable biomarkers for predicting the severity of disease. Recent preclinical studies have shown that shikonin, a natural naphthoquinone, prevents LPS-induced inflammation. However, little is known about the underlying mechanisms. Experimental Approach The binding affinity of shikonin to MD2 was analysed using computer docking, surface plasmon resonance analysis and elisa . In vitro , the anti-inflammatory effect and mechanism of shikonin were investigated through elisa , real-time quantitative reverse transcription PCR, Western blotting and immunoprecipitation assay. In vivo , lung injury was induced by intratracheal administration of LPS and assessed by changes in the histopathological and inflammatory markers. The underlying mechanisms were investigated by immunoprecipitation in lung tissue. Key Results Shikonin directly bound to MD2 and interfered with the activation of toll-like receptor 4 (TLR4) induced by LPS. In cultured macrophages, shikonin inhibited TLR4 signalling and pro-inflammatory cytokine production. These effects were produced through suppression of key signalling proteins including the NF-κB and the MAPK pathway. We also showed that shikonin inhibits MD2–TLR4 complex formation and reduces LPS-induced inflammatory responses in a mouse model of ALI. Conclusions and Implications Our studies have uncovered the mechanism underlying the biological activity of shikonin in ALI and suggest that the targeting of MD2 may prove to be beneficial as a treatment option for this condition.
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CRYSTENGCOMM
·
2017
·Vol. 19
·期 38
·5780-5786
·
IF 3.474
Kun Ding,Xiao Zhang,Juping Li,Ping Yang,Xin Cheng
Ultrathin α-Co(OH)2 nanosheets (NSs) were hydrothermally synthesized without using surfactants and templates. Interestingly, the ultrathin α-Co(OH)2 NSs evolved from graphene-like NSs to hexagonal nanoplates (NPs) and then transformed into a needle-like Co(CO3)0.5(OH)·0.11H2O phase with increasing reaction temperature and time. The phase and morphology evolution depended strongly on the CO32− ions in the solution. We ruled out the possibility that CO32− originated from the adsorption of CO2 in air and proposed the possible phase transition mechanism from α-Co(OH)2 to Co(CO3)0.5(OH)·0.11H2O, which was due to the decomposition of hexamethylenetetramine driven by dynamics and thermodynamics. The morphology evolution could be regarded as the dissolution–recrystallization–redissolution–recrystallization of α-Co(OH)2. The electrochemical behavior tests demonstrated that the ultrathin α-Co(OH)2 electrode exhibited an excellent specific capacitance of 833.4 F g−1 at 5 A g−1; however, the specific capacitance of the needle-like Co(CO3)0.5(OH)·0.11H2O electrode was 247.2 F g−1 at the same current density. This excellent electrochemical property is attributed to the crystalline phase and ultrathin nature of the materials.
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RSC Advances
·
2017
·Vol. 7
·期 65
·40705-40710
·
IF 3.108
Ruizhi Pang,Kaisong Zhang
Surface modification is a common approach to improve the desalination performance of polyamide (PA) reverse osmosis (RO) membranes. Nevertheless, the water flux normally decreases due to the additional hydraulic resistance of the surface modification layer. Surface grafted PA RO membrane with 4-(2-hydroxyethyl)morpholine was first fabricated to improve water flux in this study. 4-(2-Hydroxyethyl)morpholine was in situ grafted onto the nascent PA membrane by the reaction between the –OH group of 4-(2-hydroxyethyl)morpholine and the unreacted –COCl groups of the nascent PA membrane and residual trimesoyl chloride. The surface grafted RO membranes were characterized by X-ray photoelectron spectrometry, field emission scanning electron microscopy, atomic force microscopy and contact angle measurement. The surface grafting conditions, including 4-(2-hydroxyethyl)morpholine dipping time, heat treatment time, and 4-(2-hydroxyethyl)morpholine concentration, were optimized by characterizing the desalination performance under brackish water desalination conditions. The resulting surface grafted membrane exhibited a water flux of 125.71 L m−2 h−1 and a salt rejection of 98.6%. The surface grafted membrane surpassed the control polyamide membrane with 41.9% increase in the water flux. Our results demonstrated that surface modification by in situ grafting 4-(2-hydroxyethyl)morpholine is a promising approach to fabricate high-flux RO membranes.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Haiyan Liu,Yunfeng Bai,Jun Qin,Haiyan Wang,Yuzhen Wang,Zezhong Chen,Feng Feng
A novel sensitive fluorescence method was developed for adenosine detection by using adenosine aptamer, Exo I and a 2-aminopurine-modified DNA (2-AP probe). 2-AP probe was completely complementary to adenosine aptamer. This strategy took advantage of the high binding affinity of adenosine aptamer and the susceptibility of 2-aminopurine (2-AP) to the local base stacking environment. In the absence of the adenosine, the formation of double-stranded DNA (dsDNA) through the hybridization of the aptamer with the 2-AP probe prevented the digestion of 2-AP probe by Exo I. The fluorescence of 2-AP was significantly quenched due to the base-stacking interaction. In the presence of adenosine, the binding of adenosine with the aptamer prevented the hybridization between aptamer and 2-AP probe, leading to the digestion of 2-AP probe by Exo I and the release of 2-AP. The fluorescence was recovered. A limit of detection of 0.30 μM and a linear range from 10 μM to 600 μM ( R 2 = 0.9933) were achieved by this assay. Moreover, adenosine analogs did not produce any significant change in the fluorescence intensity response, indicating good selectivity of this sensor for adenosine detection. Finally, it was used for the diluted serum sample.
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POLYMER TESTING
·
2017
·
IF 2.464
Dong Liu,Chengsha Wei,Guanyun Yan,Guangai Sun
A series of well-defined double hydrophilic block copolymers Poly ( N -isopropylacrylamide)- b -poly (2-vinylpyridine) (PNIPAM 38 - b -P2VP 43 ) were synthesized. The ‘schizophrenic’ behavior and the aggregation process of PNIPAM- b -P2VP in response to temperature and pH in dilute aqueous solution were tested via transmittance measurements, dynamic light scattering (DLS), and small-angle neutron scattering (SANS). The results revealed that: i) both PNIPAM-core and P2VP-core micelles can be induced from an intermediate unimers state via the adjustment of temperature and pH; ii) The lower critical solution temperature (LCST) of PNIPAM homopolymers is narrowly in the range of 31–34 °C, while PNIPAM- b -P2VP diblock copolymers at pH = 7 and 2 have broad LCSTs of 25–40 °C and 41-50 °C, respectively; iii) SANS results show that only the PNIPAM- b -P2VP solution at pH = 7 and 50 °C (both blocks are hydrophobic) has a sphere form factor with diameter of about 110 nm.
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MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Siqi Cai,Dejun Li,Fang Luo,Zhenyu Lin,Aiwen Huang,Bin Qiu
In this work, an electrochemiluminescence (ECL) biosensor for T-2 toxin detection has been designed by combining the high specificity of a DNA hydrogel system with the convenience and sensitivity of homogeneous ECL detection. Specifically, A hydrogel was engineered through the reaction between the carboxyl group of hyaluronic acid (HA) and the amino groups of both polyethyleneimine (PEI) and DNA-modified strands, resulting in a three-dimensional network that encapsulates glucose oxidase. Glucose oxidase (GOD) is capable of catalyzing the conversion of glucose into hydrogen peroxide (H₂O₂), which is a co-reactant necessary for the chemiluminescent reagent luminol to emit light. Upon the presence of the target analyte T-2 toxin, the aptamer recognizes and binds to it, leading to the dissociation and cleavage of the hydrogel framework. This process results in the leakage of the encapsulated GOD into the supernatant. Subsequently, Adding the collected supernatant to a phosphate-buffered saline (PBS) solution containing glucose and luminol for ECL testing yields a noticeable signal change. This sensor eliminates the need for electrode modification, simplifying the operation. Within a concentration range of 10 fg/mL to 100 ng/mL, the ECL signal intensity exhibits an excellent linear relationship with the logarithm of the target concentration, with a detection limit as low as 0.32 fg/mL. The method also demonstrates excellent reproducibility and stability. The sensor demonstrated precise detection capabilities in actual milk and beer samples, a crucial aspect for research focused on specific targets.
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Frontiers in Plant Science
·
2024
·
IF 4.1
Xuan Zhe,Wang Yu,Shen Yuying,Pan Xiao,Wang Jiatong,Liu Wenbo,Miao Weiguo,Jin Pengfei
Background: Pepper veinal mottle virus (PVMV) belongs to the genus Potyvirus within the family Potyviridae and is a major threat to pepper production, causing reduction in yield and fruit quality; however, efficient pesticides and chemical treatments for plant protection against viral infections are lacking. Hence, there is a critical need to discover highly active and environment-friendly antiviral agents derived from natural sources. Bacillus spp. are widely utilized as biocontrol agents to manage fungal, bacterial, and viral plant diseases. Particularly, Bacillus velezensis HN-2 exhibits a strong antibiotic activity against plant pathogens and can also induce plant resistance.Methods: The experimental subjects employed in this study were Bacillus velezensis HN-2, benzothiadiazole, and dufulin, aiming to evaluate their impact on antioxidant activity, levels of reactive oxygen species, activity of defense enzymes, and expression of defense-related genes in Nicotiana benthamiana. Furthermore, the colonization ability of Bacillus velezensis HN-2 in Capsicum chinense was investigated. Results: The results of bioassays revealed the robust colonization capability of Bacillus velezensis HN-2, particularly in intercellular spaces, leading to delayed infection and enhanced protection against PVMV through multiple plant defense mechanisms, thereby promoting plant growth. Furthermore, Bacillus velezensis HN-2 increased the activities of antioxidant enzymes, thereby mitigating the PVMV-induced ROS production in Nicotiana benthamiana. Moreover, the application of Bacillus velezensis HN-2 at 5 dpi significantly increased the expression of JA-responsive genes, whereas the expression of salicylic acid-responsive genes remained unchanged, implying the activation of the JA signaling pathway as a crucial mechanism underlying Bacillus velezensis HN-2-induced anti-PVMV activity. Immunoblot analysis revealed that HN-2 treatment delayed PVMV infection at 15 dpi, further highlighting its role in inducing plant resistance and promoting growth and development. Conclusions: These findings underscore the potential of Bacillus velezensis HN-2 for field application in managing viral plant diseases effectively.
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Molbank
·
2024
·Vol. 2024
·期 2
·M1818
·
IF 0.6
Zhongwei Wang,Luxiao Zhou,Peng He,Yukun Qin
This study presents a novel approach in the realm of catalytic organic synthesis by integrating biomass catalytic conversion with organic synthesis techniques. UtilizingN-acetylglucosamine as the primary feedstock, the first phase of the research involves its catalytic transformation into 5-hydroxymethylfurfural (HMF). The subsequent phase employs a condensation reaction between HMF and 3,3-Dimethyl-2-butanone to synthesize a new compound, (E)-1-(5-(hydroxymethyl) furan-2-yl)-4,4-dimethylpent-1-en-3-one. This two-step process not only demonstrates the feasibility of converting biomass into valuable chemical precursors but also exemplifies the synthesis of novel compounds through green chemistry principles. The successful execution of this methodology offers fresh insights and opens new avenues for advancements in catalytic organic synthesis, emphasizing sustainability and efficiency.
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SENSORS
·
2025
·Vol. 25
·期 6
·1637
·
IF 3.5
Jincai Yang,Zunquan Zhao,Tianyi Ma,Jialei Bai
Point-of-care (POC) antigen detection plays a crucial role in curbing the spread of viruses. Paper-based fluorescence aptasensors are expected to offer a low-cost tool to meet the needs of decentralized POC diagnosis. Herein, we report on a fluorescent paper-based sensing system for detecting the SARS-CoV-2 spike protein. The sensing system was constructed by loading multi-layer Nb2C MXene nano-quenchers and carbon-dot-labeled aptamer (G-CDs@Apt) probes onto a mixed cellulose ester (MCE) paper substrate. On the Nb2C MXene/G-CDs@Apt sensing paper, abundant G-CDs@Apt probes were attached to the multilayer MXene nano-quenchers and kept in a fluorescence-off state, while recognition of the target detached the G-CDs@Apt probes formed the nano--quenchers, resulting in fluorescence recovery of the sensing paper. The developed paper-based sensor performed well in the one-step detection of the SARS-CoV-2 S1 protein with a detection limit of 0.067 ng/mL (0.335 pg/test). The assay exhibited good selectivity and anti-interference in the detection of the SARS-CoV-2 S1 protein in artificial saliva. Moreover, the paper-based aptasensor was successfully used to detect the SARS-CoV-2 S1 protein in actual environmental samples with recoveries of 90.87–100.55% and relative standard deviations of 1.52–3.41%. The proposed technology provides a cost-effective alternative to traditional antibody test strips for a wide range of POC diagnostic applications.
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Signal Transduction and Targeted Therapy
·
2024
·Vol. 9
·期 1
·1-13
·
IF 40.8
Yang Minghui,Li Chunhui,Ye Guoguo,Shen Chenguang,Shi Huiping,Zhong Liping,Tian Yuxin,Zhao Mengyuan,Wu Pengfei,Hussain Abid,Zhang Tian,Yang Haiyin,Yang Jun,Weng Yuhua,Liu Xinyue,Wang Zhimin,Gan Lu,Zhang Qianyu,Liu Yingxia,Yang Ge,Huang Yuanyu,Zhao Yongxiang
Emerging and recurrent infectious diseases caused by human coronaviruses (HCoVs) continue to pose a significant threat to global public health security. In light of this ongoing threat, the development of a broad-spectrum drug to combat HCoVs is an urgently priority. Herein, we report a series of anti-pan-coronavirus ssDNA aptamers screened using Systematic Evolution of Ligands by Exponential Enrichment (SELEX). These aptamers have nanomolar affinity with the nucleocapsid protein (NP) of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and also show excellent binding efficiency to the N proteins of both SARS, MERS, HCoV-OC43 and -NL63 with affinity K D values of 1.31 to 135.36 nM. Such aptamer-based therapeutics exhibited potent antiviral activity against both the authentic SARS-CoV-2 prototype strain and the Omicron variant (BA.5) with EC 50 values at 2.00 nM and 41.08 nM, respectively. The protein docking analysis also evidenced that these aptamers exhibit strong affinities for N proteins of pan-coronavirus and other HCoVs (−229E and -HKU1). In conclusion, we have identified six aptamers with a high pan-coronavirus antiviral activity, which could potentially serve as an effective strategy for preventing infections by unknown coronaviruses and addressing the ongoing global health threat.
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FUEL
·
2016
·
IF 3.611
Jingshan Wang,Xibin Wang,Xiangshan Fan,Kangkang Yang,Yingjia Zhang
Kinetic analyses were performed based on the experimental results of ignition delay times of 2-methyltetrahydrofuran (2-MTHF) using shock tube technique at temperatures of 1050–1800 K, equivalence ratios of 0.5–2.0, fuel mole concentrations of 0.25–1.0%, and pressures of 1.2–10 atm. A new kinetic model of 2-MTHF oxidation named Mech III was established according to the analysis of simulation using two published models (Mech I from Ravi Fernandes group and Mech II from Battin-Leclerc group) and the experimental data in this work. Comparison between simulation and experimental data indicated that Mech II shows remarkable under-prediction while Mech I gives a good agreement with ignition delay times under most conditions except for underprediction on fuel-rich mixtures at relative low temperature around 1250 K. Sensitivity analysis indicated that both models underestimated ignition delay times for the reactions of C 0 -C 4 molecules, so Mech III was formed by introducing such reactions and can demonstrate improved simulation performance under all conditions. Reaction pathway analysis of Mech III showed that 2-MTHF is mainly consumed through fuel decomposition at high temperatures (around 1550 K), and H-atom abstraction reactions at lower temperatures (around 1250 K), respectively. The comparative experimental and kinetic study between 2-MTHF and 2-methylfuran (MF) indicated that 2-MTHF has higher ignition delay times under the same conditions in this work, while the disparity decreases as the temperature increases, and 2-MTHF produces less soot precursors under high temperature conditions.
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