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Immune cells and interleukins play a crucial role in female-specific pain signaling. Interleukin 16 (IL-16) is a cytokine primarily associated with CD4+ T cell function. While previous studies have demonstrated the important role of spinal CD4+ T cells in neuropathic pain, the specific contribution of IL-16 to neuropathic pain remains unclear. In this study, by using a spinal nerve ligation (SNL)-induced neuropathic pain mice model, we found that SNL induced an increase in IL-16 mRNA levels, which persisted for a longer duration in female mice compared to male mice. Immunofluorescence analysis further confirmed enhanced IL-16- and CD4-positive signals in the spinal dorsal horn following SNL surgery in female mice. Knockdown of spinal IL-16 by siRNA or inhibition of CD4 by FGF22-IN-1, a CD4 inhibitor, attenuated established mechanical and thermal pain hypersensitivity induced by SNL. Furthermore, female mice injected with IL-16 intrathecally exhibited significant spontaneous pain, mechanical and thermal hyperalgesia, all of which could be alleviated by FGF22-IN-1 or a CD3 antibody. Additionally, IL-16 induced astrocyte activation but not microglial activation in the spinal dorsal horn of female mice. Meanwhile, astrocyte activation could be suppressed by the CD3 antibody. These results provide compelling evidence that IL-16 promotes astrocyte activation via CD4 on CD3+ T cells, which is critical for maintaining neuropathic pain in female mice.
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Astrocitos , Complejo CD3 , Interleucina-16 , Neuralgia , Transducción de Señal , Animales , Neuralgia/metabolismo , Femenino , Astrocitos/metabolismo , Astrocitos/efectos de los fármacos , Ratones , Masculino , Complejo CD3/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Interleucina-16/metabolismo , Antígenos CD4/metabolismo , Hiperalgesia/metabolismo , Ratones Endogámicos C57BL , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/efectos de los fármacosRESUMEN
Efferocytosis is a crucial process whereby phagocytes engulf and eliminate apoptotic cells (ACs). This intricate process can be categorized into four steps: (1) ACs release "find me" signals to attract phagocytes, (2) phagocytosis is directed by "eat me" signals emitted by ACs, (3) phagocytes engulf and internalize ACs, and (4) degradation of ACs occurs. Maintaining immune homeostasis heavily relies on the efficient clearance of ACs, which eliminates self-antigens and facilitates the generation of anti-inflammatory and immunosuppressive signals that maintain immune tolerance. However, any disruptions occurring at any of the efferocytosis steps during apoptosis can lead to a diminished efficacy in removing apoptotic cells. Factors contributing to this inefficiency encompass dysregulation in the release and recognition of "find me" or "eat me" signals, defects in phagocyte surface receptors, bridging molecules, and other signaling pathways. The inadequate clearance of ACs can result in their rupture and subsequent release of self-antigens, thereby promoting immune responses and precipitating the onset of autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes, and multiple sclerosis. A comprehensive understanding of the efferocytosis process and its implications can provide valuable insights for developing novel therapeutic strategies that target this process to prevent or treat autoimmune diseases.
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In this study, J774A.1 macrophages stimulated by lipopolysaccharide(LPS) and adenosine triphosphate(ATP) were used to establish an in vitro model of pyroptosis, and the intervention mechanism of free total rhubarb anthraquinones(FTRAs) on pyroptosis was investigated. J774A.1 macrophages were cultured in vitro, and the experiment was assigned to the control group and groups with different concentrations of LPS(0.25, 0.5, and 1 µg·mL~(-1)) and ATP(1.25, 2.5, and 5 mmol·L~(-1)). An in vitro model of macrophage pyroptosis was established by detecting cell viability through CCK-8, propidium iodide(PI) apoptotic cell staining, lactate dehydrogenase(LDH), interleukin(IL)-18, and tumor necrosis factor(TNF)-α release. Then, J774A.1 macrophages were randomly divided into six groups: blank control group, LPS+ATP group, high-dose FTRA group, and low, medium, and high-dose FTRA pre-protection group. The phenotypic characteristics and key indicators of pyroptosis were detected as the basis for evaluating the effect of FTRAs on pyroptosis induced by LPS and ATP. Western blot and RT-PCR were used to detect the expression levels of protein and mRNA related to the pyroptosis pathway in caspase-1/11 and elucidate the molecular mechanism of the anti-pyroptosis effect. The results showed that the stimulation condition of 0.50 µg·mL~(-1) LPS+5.00 mmol·L~(-1) ATP was the most effective in the in vitro model of macrophage pyroptosis. FTRAs pre-protected cells for 24 h and then can increase cell viability under pyroptosis conditions, alleviate cell damage, lower the positive rate of PI staining, and reduce the release of LDH, IL-18, and TNF-α. FTRAs were able to significantly inhibit the activation of GSDMD proteins and significantly down-regulate the protein expression of the pyroptosis pathway signature molecules, TLR4, NLRP3, cleaved-caspase-1, and cleaved-caspase-11, but they had no significant effect on ASC proteins. FTRAs were also able to significantly inhibit the mRNA expression of caspase-1, caspase-11, and GSDMD. These results indicate that FTRAs have an inhibitory effect on the pyroptosis model induced by LPS and ATP and play an anti-pyroptosis effect by regulating classical and non-classical pyroptosis signaling pathways and reducing the production of inflammatory cytokines.
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Antraquinonas , Macrófagos , Piroptosis , Rheum , Piroptosis/efectos de los fármacos , Rheum/química , Animales , Ratones , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/citología , Antraquinonas/farmacología , Antraquinonas/química , Línea Celular , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/química , Adenosina Trifosfato/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo , Lipopolisacáridos/farmacología , Supervivencia Celular/efectos de los fármacos , Interleucina-18/genética , Interleucina-18/metabolismoRESUMEN
Ethynylbenziodoxol(on)es (EB(X)xs) reagents have emerged as useful reagents for peptide/protein modification due to their versatile reactivity and high selectivity. Herein, we report the successful introduction of ethynylbenziodoxoles (EBxs) on different amino acid building blocks (Lys/Orn/Dap), and show their compatibility with both solid phase peptide synthesis (SPPS) and solution phase peptide synthesis (SPS). The selective incorporation of the EBx core into peptide sequences enable efficient macrocyclizations under mild conditions for the synthesis of topologically unique cyclic and bicyclic peptides.
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Aminoácidos , Yodo , Péptidos , Aminoácidos/química , Ciclización , Yodo/química , Péptidos/química , Péptidos/síntesis química , Técnicas de Síntesis en Fase Sólida , Estructura Molecular , Péptidos Cíclicos/química , Péptidos Cíclicos/síntesis químicaRESUMEN
Average windward area is an important index for calculating the trajectory, velocity attenuation and terminal effect of explosive fragments. In order to solve the problems that existing theoretical method cannot calculate windward area of irregular fragment and experiment method is not convenient for automatic calculation and has low accuracy, a Monte Carlo subdivision projection simulation algorithm is proposed. The average windward area of arbitrary shaped fragments can be obtained with coordinate translation, random rotation, plane projection, convex-hull triangulation, concave boundary searching and sorting with maximum edge length constraint, subdivision area calculation, and averaging by thousands of cycles. Results show that projection area obtained by the subdivision projection algorithm is basically the same as that obtained by software method of computer aided design. Moreover, the maximum calculation error of the algorithm is less than 7%, and its accuracy is much higher than that of the equivalent ellipsoid method. The average windward area calculated by the Monte Carlo subdivision projection simulation algorithm is consistent with theoretical formula for prefabricated fragments, and the error is less than 3%. The convergence and accuracy of the Monte Carlo subdivision projection algorithm are better than those of the icosahedral uniform orientation method.
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Shexiang Tongxin Dropping Pill (STP) is a composite formula of traditional Chinese medicine that is widely used for the treatment of cardiovascular diseases. It consists of seven medicinal extracts thereof or materials, including Bufonis venenum, synthetic Moschus, Panax ginseng, Bovis calculus artifactus, Bear bile powder, Salvia miltiorrhiza Bge and synthetic borneol. However, it is considerably difficult to evaluate the quality of STP due to its complex chemical compositions. This paper was designed to explore a comprehensive and systematic method combining fingerprints and chemical identification for quality assessment of STP samples. Twenty batches of STP samples were analyzed by high-performance liquid chromatography (HPLC) and high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry. Ten common peaks were detected by HPLC fingerprint similarity evaluation system. Meanwhile, 100 compounds belonging to 4 structural characteristics, including 23 bufadienolides, 36 organic acids, 34 saponins and 7 other types, were systematically identified as the basic components in STP. This study could be used for clarifying the multiple bioactive substances and developing a comprehensive quality evaluation method of STP.
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BACKGROUND: Abernethy malformation, also known as congenital extrahepatic portosystemic shunt, is an uncommon malformation resulting from aberrant development of the portal venous system. Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene. It mainly affects the exocrine glands of the respiratory, digestive and reproductive systems. It is considered extremely rare in the Asian population. We present a clinical case involving a pediatric patient of Asian descent who was diagnosed with Abernethy malformation and CF. CASE SUMMARY: A 12-year-old girl presented with a medical history of recurring respiratory infections and hemoptysis, and chest computed tomography (CT) showed bronchiectasis. Whole exome sequencing was performed for the patient, yielding findings that revealed a compound heterozygous variant of the CFTR gene: c.233_c.234insT/p.Trp79fsTer3 (maternal origin); c.2909G>A/p.Gly970Asp (paternal origin). CF was diagnosed. The physician's attention was drawn to the presence of splenomegaly during disease progression. Abdominal enhanced CT revealed splenomegaly, compression of the left kidney, and multiple tortuous dilated vascular shadows were seen at the splenic hilum, which flowed back into the left renal vein and portal vein, suggesting Abernethy malformation type II. Intraoperatively, the abnormal blood flow was seen to merge into the inferior vena cava through the left renal vein without hepatic processing, and the pathology of liver biopsy showed hypoplastic, dilated or absent portal vein branches, both of which supported the diagnosis of Abernethy malformation type II. This represents the initial documented instance of Abernethy malformation accompanied by a CFTR gene mutation in the existing body of literature. CONCLUSION: Coexisting Abernethy malformation and CF are rare. Detailed medical history information, abdominal enhanced CT, venography and genetic testing contribute to diagnosis as well as differential diagnosis.
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The 3-succinate-30-stearyl glycyrrhetinic acid(18-GA-Suc) was inserted into glycyrrhetinic acid(GA)-tanshinone â ¡_A(TSN)-salvianolic acid B(Sal B) liposome(GTS-lip) to prepare liver targeting compound liposome(Suc-GTS-lip) mediated by GA receptors. Next, pharmacokinetics and tissue distribution of Suc-GTS-lip and GTS-lip were compared by UPLC, and in vivo imaging tracking of Suc-GTS-lip was conducted. The authors investigated the effect of Suc-GTS-lip on the proliferation inhibition of hepatic stellate cells(HSC) and explored their molecular mechanism of improving liver fibrosis. Pharmacokinetic results showed that the AUC_(Sal B) decreased from(636.06±27.73) µg·h·mL~(-1) to(550.39±12.34) µg·h·mL~(-1), and the AUC_(TSN) decreased from(1.08±0.72) µg·h·mL~(-1) to(0.65±0.04) µg·h·mL~(-1), but the AUC_(GA) increased from(43.64±3.10) µg·h·mL~(-1) to(96.21±3.75) µg·h·mL~(-1). The results of tissue distribution showed that the AUC_(Sal B) and C_(max) of Sal B in the liver of the Suc-GTS-lip group were 10.21 and 4.44 times those of the GTS-lip group, respectively. The liver targeting efficiency of Sal B, TSN, and GA in the Suc-GTS-lip group was 40.66%, 3.06%, and 22.08%, respectively. In vivo imaging studies showed that the modified liposomes tended to accumulate in the liver. MTT results showed that Suc-GTS-lip could significantly inhibit the proliferation of HSC, and RT-PCR results showed that the expression of MMP-1 was significantly increased in all groups, but that of TIMP-1 and TIMP-2 was significantly decreased. The mRNA expressions of collagen-I and collagen-â ¢ were significantly decreased in all groups. The experimental results showed that Suc-GTS-lip had liver targeting, and it could inhibit the proliferation of HSC and induce their apoptosis, which provided the experimental basis for the targeted treatment of liver fibrosis by Suc-GTS-lip.
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Ácido Glicirretínico , Liposomas , Humanos , Células Estrelladas Hepáticas , Ácido Glicirretínico/farmacología , Hígado , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/genética , Colágeno/farmacologíaRESUMEN
Rapid and efficient cyclization methods that form structurally novel peptidic macrocycles are of high importance for medicinal chemistry. Herein, we report the first gold(I)-catalyzed macrocyclization of peptide-EBXs (ethynylbenziodoxolones) via C2-Trp C-H activation. This reaction was carried out in the presence of protecting group free peptide sequences and is enabled by a simple commercial gold catalyst (AuCl·Me2S). The method displayed a rapid reaction rate (within 10 min), wide functional group tolerance (27 unprotected peptides were cyclized), and up to 86% isolated yield. The obtained highly conjugated cyclic peptide linker, formed through C-H alkynylation, can be directly applied to live-cell imaging as a fluorescent probe without further attachment of fluorophores.
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Péptidos Cíclicos , Péptidos , Secuencia de Aminoácidos , Ciclización , Catálisis , Colorantes FluorescentesRESUMEN
We reveal the gate-tunable Berry curvature dipole polarizability in Dirac semimetal Cd_{3}As_{2} nanoplates through measurements of the third-order nonlinear Hall effect. Under an applied electric field, the Berry curvature exhibits an asymmetric distribution, forming a field-induced Berry curvature dipole, resulting in a measurable third-order Hall voltage with a cubic relationship to the longitudinal electric field. Notably, the magnitude and polarity of this third-order nonlinear Hall effect can be effectively modulated by gate voltages. Furthermore, our scaling relation analysis demonstrates that the sign of the Berry curvature dipole polarizability changes when tuning the Fermi level across the Dirac point, in agreement with theoretical calculations. The results highlight the gate control of nonlinear quantum transport in Dirac semimetals, paving the way for promising advancements in topological electronics.
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BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as Churg-Strauss syndrome, is a rare form of anti-neutrophil cytoplasmic antibody-associated vasculitis characterized by asthma, vasculitis, and eosinophilia. CASE SUMMARY: We report an atypical case of EGPA in a 20-year-old female patient. Unlike previously reported cases of EGPA, this patient's initial symptom was asthma associated with a respiratory infection. This was followed by Loeffler endocarditis and cardiac insufficiency. She received treatment with methylprednisolone sodium succinate, low molecular weight heparin, recombinant human brain natriuretic peptide, furosemide, cefoperazone sodium/sulbactam sodium, and acyclovir. Despite prophylactic anticoagulation, she developed a large right ventricular thrombus. EGPA diagnosis was confirmed based on ancillary test results and specialty consultations. Subsequent treatment included mycophenolate mofetil. Her overall condition improved significantly after treatment, as evidenced by decreased peripheral blood eosinophils and cardiac markers. She was discharged after 17 d. Her most recent follow-up showed normal peripheral blood eosinophil levels, restored cardiac function, and a reduced cardiac mural thrombus size. CONCLUSION: This case illustrates the swift progression of EGPA and underscores the significance of early detection and immediate intervention to ensure a favorable prognosis.
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Bis(trifluoromethylated)benziodoxoles (Bx) are broadly used cyclic hypervalent iodine reagents due to their stability and unique chemical properties. However, current methods to access them require several steps and long reaction times, making their synthesis tedious. Herein, a direct one-pot synthesis of bis(trifluoromethylated) Bx reagents from iodine(I) precursors is reported, enabling the synthesis of functionalized reagents.
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Herein, we report a novel strategy for the modification of peptides based on the introduction of highly reactive hypervalent iodine reagents-ethynylbenziodoxolones (EBXs)-onto peptides. These peptide-EBXs can be readily accessed, by both solution- and solid-phase peptide synthesis (SPPS). They can be used to couple the peptide to other peptides or a protein through reaction with Cys, leading to thioalkynes in organic solvents and hypervalent iodine adducts in water buffer. Furthermore, a photocatalytic decarboxylative coupling to the C-terminus of peptides was developed using an organic dye and was also successful in an intramolecular fashion, leading to macrocyclic peptides with unprecedented crosslinking. A rigid linear aryl alkyne linker was essential to achieve high affinity for Keap1 at the Nrf2 binding site with potential protein-protein interaction inhibition.
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Yodo , Indicadores y Reactivos , Proteína 1 Asociada A ECH Tipo Kelch , Yodo/química , Factor 2 Relacionado con NF-E2 , Péptidos/químicaRESUMEN
The fibrillation process of human insulin (HI) is closely related to the therapy for type II diabetes (T2D). Due to changes in the spatial structure of HI, the fibrillation process of HI takes place in the body, which leads to a significant decrease in normal insulin levels. L-Lysine CDs with a size of around 5 nm were synthesized and used to adjust and control the fibrillation process of HI. ThT fluorescence analysis and transmission electron microscopy (TEM) characterization of the CDs showed the role of HI fibrillation from the perspective of the kinetics of HI fibrillation and regulation. Isothermal titration calorimetry (ITC) was used to explore the regulatory mechanism of CDs at all stages of HI fibrillation from the perspective of thermodynamics. Contrary to common sense, when the concentration of CDs is less than 1/50 of the HI, CDs will promote the growth of fibres, while a high concentration of CDs will inhibit the growth of fibres. The experimental results of ITC clearly prove that different concentrations of CDs will correspond to different pathways of the combination between CDs and HI. CDs have a strong ability to combine with HI during the lag time, and the degree of combination has become the main factor influencing the fibrillation process.
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Diabetes Mellitus Tipo 2 , Puntos Cuánticos , Humanos , Lisina , Puntos Cuánticos/química , Carbono/química , Diabetes Mellitus Tipo 2/tratamiento farmacológico , InsulinaRESUMEN
The chemokine CCL5 plays a potential role in the occurrence and development of colorectal cancer (CRC). Previous studies have shown that CCL5 directly acts on tumor cells to change tumor metastatic rates. In addition, CCL5 recruits immune cells and immunosuppressive cells into the tumor microenvironment (TME) and reshapes the TME to adapt to tumor growth or increase antitumor immune efficacy, depending on the type of secretory cells releasing CCL5, the cellular function of CCL5 recruitment, and the underlying mechanisms. However, at present, research on the role played by CCL5 in the occurrence and development of CRC is still limited, and whether CCL5 promotes the occurrence and development of CRC and its role remain controversial. This paper discusses the cells recruited by CCL5 in patients with CRC and the specific mechanism of this recruitment, as well as recent clinical studies of CCL5 in patients with CRC.Key MessagesCCL5 plays dual roles in colorectal cancer progression.CCL5 remodels the tumor microenvironment to adapt to colorectal cancer tumor growth by recruiting immunosuppressive cells or by direct action.CCL5 inhibits colorectal cancer tumor growth by recruiting immune cells or by direct action.
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Quimiocina CCL5 , Neoplasias Colorrectales , Humanos , Línea Celular Tumoral , Microambiente TumoralRESUMEN
BACKGROUND: Gallbladder carcinoma (GBC) is highly malignant, and its early diagnosis remains difficult. This study aimed to develop a deep learning model based on contrast-enhanced computed tomography (CT) images to assist radiologists in identifying GBC. METHODS: We retrospectively enrolled 278 patients with gallbladder lesions (> 10 mm) who underwent contrast-enhanced CT and cholecystectomy and divided them into the training (n = 194) and validation (n = 84) datasets. The deep learning model was developed based on ResNet50 network. Radiomics and clinical models were built based on support vector machine (SVM) method. We comprehensively compared the performance of deep learning, radiomics, clinical models, and three radiologists. RESULTS: Three radiomics features including LoG_3.0 gray-level size zone matrix zone variance, HHL first-order kurtosis, and LHL gray-level co-occurrence matrix dependence variance were significantly different between benign gallbladder lesions and GBC, and were selected for developing radiomics model. Multivariate regression analysis revealed that age ≥ 65 years [odds ratios (OR) = 4.4, 95% confidence interval (CI): 2.1-9.1, P < 0.001], lesion size (OR = 2.6, 95% CI: 1.6-4.1, P < 0.001), and CA-19-9 > 37 U/mL (OR = 4.0, 95% CI: 1.6-10.0, P = 0.003) were significant clinical risk factors of GBC. The deep learning model achieved the area under the receiver operating characteristic curve (AUC) values of 0.864 (95% CI: 0.814-0.915) and 0.857 (95% CI: 0.773-0.942) in the training and validation datasets, which were comparable with radiomics, clinical models and three radiologists. The sensitivity of deep learning model was the highest both in the training [90% (95% CI: 82%-96%)] and validation [85% (95% CI: 68%-95%)] datasets. CONCLUSIONS: The deep learning model may be a useful tool for radiologists to distinguish between GBC and benign gallbladder lesions.
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Fibrillation process of human insulin (HI) is closely related to type 2 diabetes (T2D). In the present work, Carbon Polymer Dots (CPDs) was synthesized by Bodipy to control the process of insulin fibrillation. The inhibition process of insulin fibrillation with the existence of CPDs was completed investigated. The hydrophobic interaction of CPDs and insulin was used to inhibit the change of insulin's secondary structure in the lag phase and growth period. ThT fluorescence analysis and transmission electron microscopy (TEM) characterization of the CPDs were used to explore the kinetics of insulin fibrillation and regulation process by CPDs. Isothermal titration calorimetry (ITC) was applied to explore the regulatory mechanism by CPDs at all stages of the insulin fibrillation process. ThT was used to complete the chemical modification of CPDs by Friedel-Crafts alkylation, which made the CPDs maintain the characteristics of photothermal effect and also obtain the ability to bind specifically to the fibers. Finally, the process of defibrillation of human insulin fibers under the Near-infrared light's irradiation was realized. In this work, we clarified the mechanism of the regulation process by Bodipy CPDs and made CPDs able to defibrillate the insulin fibers by chemical modification.
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Diabetes Mellitus Tipo 2 , Polímeros , Humanos , Polímeros/farmacología , Polímeros/química , Carbono/química , Insulina/química , CalorimetríaRESUMEN
The transcription factor, sterol regulatory element binding protein 1 (SREBP-1), plays important roles in modulating the proliferation, metastasis, or resistance to antitumor agents by promoting cellular lipid metabolism and related cellular glucose-uptake/Warburg Effect. However, the underlying mechanism of SREBP-1 regulating the proliferation or drug-resistance in lung squamous cell carcinoma (LUSC) and the therapeutic strategies targeted to SREBP-1 in LUSC remain unclear. In this study, SREBP-1 was highly expressed in LUSC tissues, compared with the paired non-tumor tissues (the para-tumor tissues). A novel small-molecule inhibitor of SREBP-1, MSI-1 (Ma's inhibitor of SREBP-1), based on natural product monomers, was identified by screening the database of natural products. Treatment with MSI-1 suppressed the activation of SREBP-1-related pathways and the Warburg effect of LUSC cells, as indicated by decreased glucose uptake or glycolysis. Moreover, treatment of MSI-1 enhanced the sensitivity of LUSC cells to antitumor agents. The specificity of MSI-1 on SREBP-1 was confirmed by molecular docking and point-mutation of SPEBP-1. Therefore, MSI-1 improved our understanding of SREBP-1 and provided additional options for the treatment of LUSC.
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The conventional ferrocyanide complex ([Fe(CN)6]4-) has been widely used as a scale inhibitor under mild conditions, but its oxidation at high temperature compromises the subsequent wastewater treatment processes. To conquer the inadequacies of Fe(CN)6]4-, aminotriacetamide (NTA) was synthesized using chloroacetic acid as an initial material and its molecular structure was characterized using FT-IR spectroscopy, H-NMR, and TGA. NTA was exploited in combination with polyaspartic acid (PASP) and sodium dodecyl benzene sulfonate (SDBS) to prepare a high-performance antisalt composite, and the scaling inhibitor performance was evaluated. The results revealed that as the concentration of the antisalt composite increased from 0.5 to 1.2 wt %, the solubility and inhibition rate increased by 95.6 and 12.33%, respectively, at 100 °C. The results from molecular simulation evidenced that the order of binding energy between a unit mass of the salt inhibitor and sodium chloride crystal increased in the following order; SDBS > NTA > PASP. The deformation strength between the salt inhibitor and sodium chloride crystal increased as follows: NTA > PASP > SDBS. In addition, the antisalt composite mainly hampered salt precipitation through strong adsorptions arising from both the nitrogen atom of NTA and oxygen atom of SDBS with the sodium atom of sodium chloride crystals, and as a result, it not only altered the crystalline form of sodium chloride but also reduced the adsorption of sodium atoms and eventually improved the salt solubility.
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Carbon dots (CDs) have been widely used in recent years because of their excellent water solubility and abundant surface functional groups. However, compared with quantum dots or biological probes, the quantum yield of CDs is lower, and the fluorescence mainly concentrated in the blue-green range, which significantly limits the biological applications of CDs. Heteroatoms doping is the most common method to improve the luminescence of CDs. In this work, nitrogen and sulfur co-doped luminescent CDs were successfully synthesized by microwave assisted method using glutathione (GSH) and p-phenylenediamine (PPD) as raw materials. It can emit bright green fluorescence in ethanol solution, and the maximum emission wavelength is 535 nm when excited at 374 nm, and the absolute quantum yield is as high as 63%. Iron ion (Fe3+) can interact with the functional groups on the surface of the CDs to form CDs/Fe3+, which is a non-fluorescence complex, and Fe3+ can be reduced to ferrous ion (Fe2+). In other words, the reaction mechanism of CDs and Fe3+ is a combination of dynamic quenching and static quenching. The fluorescence of CDs quenched by Fe3+ can be restored by thiol, because there is a stronger binding force between sulfhydryl (-SH) on the surface of thiol and Fe3+, which enables CDs to be released. In addition, the CDs has good biocompatibility and stability, indicating that it has excellent potential in bioimaging. This discovery will expand the application of CDs in the fields of biosensing and imaging.