Nonalternating purine pyrimidine sequences can form stable left-handed DNA duplex by strong topological constraint.

In vivo, left-handed DNA duplex (usually refers to Z-DNA) is mainly formed in the region of DNA with alternating purine pyrimidine (APP) sequence and plays significant biological roles. It is well known that d(CG)n sequence can form Z-DNA most easily under negative supercoil conditions, but its essence has not been well clarified. The study on sequence dependence of Z-DNA stability is very difficult without modification or inducers. Here, by the strong topological constraint caused by hybridization of two complementary short circular ssDNAs, left-handed duplex part was generated for various sequences, and their characteristics were investigated by using gel-shift after binding to specific proteins, CD and Tm analysis, and restriction enzyme cleavage. Under the strong topological constraint, non-APP sequences can also form left-handed DNA duplex as stable as that of APP sequences. As compared with non-APP sequences, the thermal stability difference for APP sequences between Z-form and B-form is smaller, which may be the reason that Z-DNA forms preferentially for APP ones. This result can help us to understand why nature selected APP sequences to regulate gene expression by transient Z-DNA formation, as well as why polymer with chirality can usually form both duplexes with left- or right-handed helix.

A sensitive and high-throughput LC-ESI-MS/MS method to detect budesonide in human plasma: application to an evaluation of pharmacokinetics of budesonide intranasal formulations with and without charcoal-block in healthy volunteers.

Budesonide is one of the intranasal corticosteroids, referred as first-line therapy for allergic rhinitis. Its determination is a challenging task due to its extremely low plasma levels, which limits the progress in the investigation of pharmacokinetics and quality control of preparations. In this study, a sensitive and high-throughput method to determine budesonide in human plasma using budesonide-d8 as the internal standard was developed and validated. A small volume of plasma sample (0.2 mL) was diluted with 0.2 mL water, followed by a solid-phase extraction using Cleanert PEP-2 products. Extracted samples were analyzed by liquid chromatography coupled to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Chromatographic separation of analytes was performed on an InertSustain AQ-C18 HP column (3 µm, 2.1 × 50 mm) under the reversed-phase condition with gradient elution. With the assay, linear calibration curves were obtained over the concentration range of 10-1200 pg/mL for budesonide, with considerable extraction recoveries (84.7-89.4%), and negligible matrix effects (<4.1). Moreover, the newly developed method was successfully applied to the evaluation of pharmacokinetics of two budesonide intranasal formulations with and without charcoal block in healthy volunteers.

[Research progress on protective effect of traditional Chinese medicine and natural medicine on methotrexate-induced liver toxicity].

Methotrexate(MTX) is a commonly used antimetabolite, which can be used in the treatment of a variety of diseases. However, hepatotoxicity in the use of MTX severely limits its clinical use. Therefore, how to prevent and treat hepatotoxicity of MTX has become an urgent clinical problem. This paper summarizes and analyzes relevant literatures on the prevention and treatment of hepa-totoxicity caused by MTX with traditional Chinese medicines and natural medicines in recent years. MTX-induced hepatotoxicity mechanisms include folate pathway, oxidative stress damage and adenosine pathway, of which oxidative stress theory is the main research direction. A total of 14 kinds of traditional Chinese medicine and natural medicine extracts including white peony root, and 21 kinds of natural monomer compounds, including berberine, play an anti-MTX-induced hepatotoxic effect by resisting oxidative stress, inhibiting inflammation and regulating signal pathways. According to current studies on the prevention and treatment of hepatotoxicity induced by MTX with traditional Chinese medicines and natural medicines, there are insufficiencies, such as partial and superficial mechanism studies, inadequate combination of experimental research and clinical practice, non-standard experimental design and lack of application of advanced technologies and methods. This paper systematically reviewed the effects and mechanisms of traditional Chinese medicines and natural medicines against hepatotoxicity induced by MTX and defined current studies and deficiencies, in the expectation of proposing new study strategies and directions and providing scientific basis for rational clinical use of MTX and development of new drugs against MTX hepatotoxicity.

A near infrared fluorescent probe based on ICT for monitoring mitophagy in living cells.

Mitophagy, the process in which cells degrade dysfunctional organelles and recycle their nutrient substances by lysosomes, plays a vital role in cell metabolism and physiology. Herein, we present a highly targeting and near-infrared (NIR) mitochondrion fluorescent probe, which can monitor the process of autophagy. The response mechanism of the probe is based on intramolecular charge transfer (ICT) for the detection of autophagy and real-time imaging of living cells. We designed a primary amine as a pH sensitizing group, and due to the ICT process, the probe exhibits green fluorescence, and when it is protonated the ICT process is broken, and the NIR fluorescence will be restored. Simultaneously, the green fluorescence of the probe disappears. This probe exhibits excellent selectivity, high sensitivity and clean responsiveness, which indicate that it can be applied for high-targeting and high-sensitive imaging of the process of autophagy in living systems.

Convenient synthesis of three-dimensional hierarchical CuS@Pd core-shell cauliflowers decorated on nitrogen-doped reduced graphene oxide for non-enzymatic electrochemical sensing of xanthine.

A novel hybrid with three-dimensional (3D) hierarchical CuS@Pd core-shell cauliflowers decorated on nitrogen-doped reduced graphene oxide (CuS@Pd/N-RGO) has been prepared by a facile wet-chemical route without utilizing any template molecules and surfactants. The characterization results reveal that the 3D flower-like structure of CuS "core" is composed of interconnecting nanoplates, which is conductive to the loading of Pd nanoparticles' "shell" and results in the robust interaction between the core and shell for the formation of CuS@Pd cauliflowers. Anchoring such appealing CuS@Pd cauliflowers on the two-dimensional N-RGO can efficaciously inhibit the aggregation of CuS@Pd cauliflowers and accelerate the kinetics of xanthine oxidation. Benefiting from the multi-functional properties and unique morphology, the sensor constructed by CuS@Pd/N-RGO exhibits excellent performance for non-enzymatic detection of xanthine including a wide detection range of 0.7-200.0 µM (0.94 V vs. SCE), a low detection limit of 28 nM (S/N = 3), high reproducibility (relative standard deviation (RSD) = 4.1%), and commendable stability (retained 90% of the initial electrochemical responses after storage for 30 days), which is amongst the best of various electrochemical sensors reported for xanthine assays till date. Reliable and satisfying recoveries (95-105%, RSD ≤ 4.1%) are achieved for xanthine detection in real samples. The inspiring results make the uniquely structural CuS@Pd/N-RGO greatly promising in non-enzymatic electrochemical sensing applications. Graphical abstract A high-performance non-enzymatic xanthine sensor has been constructed by the three-dimensional hierarchical CuS@Pd core-shell cauliflowers decorated on nitrogen-doped reduced graphene oxide.

The association between anti-tumor potency and structure-activity of protein-kinases inhibitors based on quinazoline molecular skeleton.

Quinazoline was originally utilized as an anti-tumor treatment, and its various derivatives can be directly extracted from plants. In recent years, protein kinases (PK) have been well recognized in the development of tumor drugs. Functionally, PK serves a vital role in the apoptosis, proliferation, differentiation, migration and cell cycle of tumor cells. Due to its good physicochemical properties, quinazoline skeleton, a superior type of PK inhibitor, has been extensively used in anti-tumor drug design. An increasing number of studies on quinazoline synthesis have been reported and used by different groups to effectively develop novel derivatives. Thus, several studies have been approved for the use of quinazoline derivatives as inhibitors of other kinases, including Src and histone deacetylase. The aim of the present review was to summarize the mechanism of quinazoline compounds as PK inhibitors, their biological structure-activity relationship such as the substituted quinazoline compounds with different functional groups in the apoptotic process, and their effect on the proliferation of tumor cells. The development of novel agents based on the antitumor functions of quinazoline molecular compounds may improve the clinical outcomes of the affected population, particularly in patients with cancer.

Candidate Regulatory Genes for Hindlimb Development in the Embryos of the Chinese Alligator (Alligator sinensis).

Crocodilians, which are a kind of animal secondary adaptation to an aquatic environment, their hindlimb can provide the power needed to engage in various life activities, even in low-oxygen water environments. The development of limbs is an important aspect of animal growth and development, as it is closely linked to body movement, support, heat production, and other critical functions. For the Chinese alligator, the hindlimb is one of the main sources of power, and its development and differentiation will directly influence the survival ability in the wild. Furthermore, a better understanding of the hindlimb developmental process will provide data support for the comparative evolutionary and functional genomics of crocodilians. In this study, the expression levels of genes related to hindlimb development in the Chinese alligator embryos during fetal development (on days 29, 35, 41, and 46) were investigated through transcriptome analysis. A total of 1675 differentially expressed genes (DEGs) at different stages were identified by using limma software. These DEGs were then analyzed using weighted correlation network analysis (WGCNA), and 4 gene expression modules and 20 hub genes were identified that were associated with the development of hindlimbs in the Chinese alligator at different periods. The results of GO enrichment and hub gene expression showed that the hindlimb development of the Chinese alligator embryos involves the development of the embryonic structure, nervous system, and hindlimb muscle in the early stage (H29) and the development of metabolic capacity occurs in the later stage (H46). Additionally, the enrichment results showed that the AMPK signaling pathway, calcium signaling pathway, HIF-1 signaling pathway, and neuroactive ligand-receptor interaction are involved in the development of the hindlimb of the Chinese alligator. Among these, the HIF-1 signaling pathway and neuroactive ligand-receptor interaction may be related to the adaptation of Chinese alligators to low-oxygen environments. Additionally, five DEGs (CAV1, IRS2, LDHA, LDB3, and MYL3) were randomly selected for qRT-PCR to verify the transcriptome results. It is expected that further research on these genes will help us to better understand the process of embryonic hindlimb development in the Chinese alligator.

An aggregation-induced emission fluorescent probe for highly sensitive and selective detection and imaging of Hg2+ in living cells.

Mercury ions (Hg2+), as one of heavy transition metals (HTM), is a highly toxic metal that is hazardous to human health. Here an aggregation-induced emission (AIE) fluorescent probe is designed for the highly sensitive and selective detection of Hg2+. The probe is engineered with a tetraphenylethene (TPE) derivative as the fluorophore and thiopropionic acid as the site of recognition for Hg2+. Due to the different solubilities of the probe AIE-COOH and its corresponding product after reaction with Hg2+. The probe demonstrates a maximum detection limit of 22 nM and a fast response time of âˆ¼100 s. Simultaneously, AIE-COOH exhibits outstanding detectivity and hypersensitivity for the detection of Hg2+ in aqueous solutions. These characteristics demonstrate that AIE-COOH hold a great potential in environmental, food and biological systems. Moreover, we have also successfully applied it to Hg2+ fluorescence imaging in in living cells.

An AIE based fluorescent chemosensor for ratiometric detection of hypochlorous acid and its application.

Detecting and imaging intracellular hypochlorous acid (HClO) is of great importance owning to its prominent role in numerous pathological and physiological processes. In this contribution, a novel AIE-based fluorescent chemosensor has been developed by employing a benzothiazole derivative. The synthesized probe displayed remarkable ratiometric fluorescent response to HClO with a large emission shift (139 nm), resulting in naked-eye fluorescence changes from red to blue. Under the optimal conditions, this probe was capable of quantitatively detecting HClO within 10 s, and possessed good sensitivity and high selectivity toward HClO over other biologically relevant species. Moreover, it has been successfully utilized to image the exogenous and endogenous HClO in living cells through dual channels, and conveniently detect hypochlorous acid solution on test strips with better accuracy, demonstrating its potential for monitoring HClO in biological and environment fields.

Protonation enhanced superconductivity in PdTe2.

Electrochemical ionic liquid gating is an effective way to intercalate ions into layered materials and modulate the properties. Here we report an enhanced superconductivity in a topological superconductor candidate PdTe2through electrochemical gating procedure. The superconducting transition temperature was increased to approximately 3.2 K by ionic gating induced protonation at room temperature. Moreover, a further enhanced superconductivity of both superconducting transition temperature and superconducting volume fraction was observed after the gated samples were placed in a glove box for 2 months. This may be caused by the diffusion of protons in the gated single crystals, which is rarely reported in electrochemical ionic liquid gating experiments. Our results further the superconducting study of PdTe2and may reveal a common phenomenon in the electrochemical gating procedure.

Orcinol Glucoside Improves Senile Osteoporosis through Attenuating Oxidative Stress and Autophagy of Osteoclast via Activating Nrf2/Keap1 and mTOR Signaling Pathway.

Oxidative stress and autophagy play essential roles in the development of senile osteoporosis which is characterized by disrupted osteoclastic bone resorption and osteoblastic bone formation. Orcinol glucoside (OG), a phenolic glycoside isolated from Curculigo orchioides Gaertn, possesses antiosteoporotic properties. This study examined the protective effects of OG on bone loss in SAMP6 mice and explored the underlying mechanisms. The osteoporotic SAMP6 mice were treated with OG oral administration. RAW264.7 cells were induced to differentiate into osteoclast by RANKL and H2O2 in vitro and received OG treatment. The results demonstrated that OG attenuated bone loss in SAMP6 mice and inhibited the formation and bone resorption activities of osteoclast and reduced levels of oxidative stress in bone tissue of SAMP6 mice and osteoclast. Furthermore, OG activated Nrf2/Keap1 signaling pathway and enhanced the phosphorylation of mTOR and p70S6K which are consequently suppressing autophagy. Of note, the effect of OG on Nrf2/Keap1 signaling was neutralized by the mTOR inhibitor rapamycin. Meanwhile, the inhibitory effect of OG on autophagy was reversed by the Nrf2 inhibitor ML385.Conclusively, OG attenuated bone loss by inhibiting formation, differentiation, and bone resorption activities of osteoclast. Regulation of Nrf2/Keap1 and mTOR signals is a possible mechanism by which OG suppressed oxidative and autophagy of osteoclasts. Thus, OG prevented senile osteoporosis through attenuating oxidative stress and autophagy of osteoclast via activating Nrf2/Keap1 and mTOR signaling pathway.

Intergenerational Factors Influencing Household Cohabitation in Urban China: Chengdu.

Family composition impacts individual consumption habits, which may potentially transform urban integral space structure. Due to the reform in the housing system at the end of the 1990s and increases in residents' income, houses became more affordable, and intergenerational household cohabitation is no longer the primary pattern. Nonetheless, as families change, it still remains an important form of family composition. Intergenerational support is important in household habitation. This study examines the temporal changes and the structure of intergenerational household cohabitation. Moreover, intergenerational factors in groups of all genders and ages are analyzed. We found that intergenerational household cohabitation in Chengdu comprises three structures: elders living with married children, elders living with unmarried children, and elders living with grandchildren. According to multiple logistic regression, we can see that inadequate housing, economy of costs, cases of emergency, fear of loneliness, care of grandchildren, and poor health have marked effects on household cohabitation, and the positive or negative effects are distinct regarding different structures. To be more specific, the significance of financial support in family composition decreases, and that of support in daily care increases with age. The influence of financial support, daily care support, and emotional support peaks among those aged between 35-60, followed by individuals under 35, and those aged over 60. Financial support is comparatively important for individuals under 35, and females attach more importance to emotional support in intergenerational household cohabitation. The findings provide a basis for subsequent studies of family composition.

A colorimetric and far-red fluorescent probe for rapid detection of bisulfite/sulfite in full water-soluble based on biquinolinium and its applications.

Bisulfite (HSO3-) and sulfite (SO32-) are involved in numerous physiological processes of living systems. However, high levels of these substances are often correlated to many diseases. Herein, we designed and synthesized a simple full water-soluble colorimetric and far-red fluorescent probe (E)-1-methyl-4-(2-(1-methylquinolin-1-ium-3-yl)vinyl)quinolin-1-ium iodide trifluoromethanesulfonate (DQ) for HSO3-/SO32- detection by coupling 1,4-dimethylquinolinium with 3-quinolinium carboxaldehyde for the first time. The probe DQ showed high selectivity for HSO3- detection via a 1,4-nucleophilic addition reaction with distinct color changes from colorless to purple-red and remarkable far-red fluorescence enhancement in pure aqueous solutions. Specifically, the probe displayed a fast response (<15 s) for bisulfite, which renders it suitable for real time detection of HSO3-. Under the optimized conditions, the far-red fluorescence intensity was linear to the concentrations of HSO3- in the range from 0 to 25 µM and the detection limit was as low as 0.11 µM. Additionally, the probe could be applied to sense HSO3- on paper strips, real sample including vermicelli and sugar and image HSO3- in living cells, which indicated that probe DQ has potential application in food samples and living systems.

Curculigoside attenuates oxidative stress and osteoclastogenesis via modulating Nrf2/NF-κB signaling pathway in RAW264.7 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Curculigo orchioides Gaertn is used for the treatment of impotence, atrophic debility of bones (osteoporosis), limb limpness, and arthritis of the lumbar and knee joints in traditional Chinese medicine and Ayurvedic medical system. Curculigoside (Cur) from Curculigo orchioides Gaertn has been shown to have regulatory effects on bone metabolism via anti-oxidative activities in rats and osteoblasts. However, little is known about the molecular pharmacological activity of Cur in osteoclastic bone resorption. AIM: The aim of this work is to investigate the inhibitory effect of Cur against osteoclasts (OCs) under the oxidative stress status, and explore the possible underlying mechanism. MATERIALS AND METHODS: OCs were induced from RAW264.7 cells using RANKL and H2O2. The number of OCs was measured by tartrate-resistant acid phosphatase (TRAP) staining. F-Actin and nuclear translocation of P65 and Nrf2 were stained with immunofluorescence assay and observed under a laser confocal microscope. The biochemical parameters of OCs were detected with an ELISA kit. The expression of Nrf2 and NF-κB pathway-related proteins was analyzed by Western Blot. RESULTS: Cur inhibited the TRAP activity, release of degrading products from bone slices and the expression of NFATc1, c-Fos, Cathepsin K (Ctsk) and matrix metallopeptidase 9 (MMP9) of OCs induced with RANKL and H2O2. In addition, Cur suppressed the ROS level and NADPH oxidase 1(NOX1) and NADPH oxidase 4 (NOX4) activities of OCS. More importantly, Cur enhanced the expression and nucleus translocation of Nrf2 and activities of its regulatory cytoprotective enzymes, and reduced the NF-κB expression and phosphorylation and nucleus translocation of p65 in OCs. Furthermore, the Nrf2 inhibitor ML385 and NF-κB inhibitor Bay11-7082 counteracted the effect of Cur in OCs. CONCLUSION: Cur mitigated oxidative stress and osteoclastogenesis by activating Nrf2 and inhibiting the NF-κB pathway, suggesting that Cur may prove to be a promising candidate for the treatment of osteoporosis. Our findings may also help partially explain the rationale behind the traditional use of Curculigo orchioides Gaertn.

Application of a Colorimetric and Near-Infrared Fluorescent Probe in Peroxynitrite Detection and Imaging in Living Cells.

Peroxynitrite (ONOO-) plays a vital role in pathological and physiological processes, and an excessive amount of ONOO- causes various diseases. Developing a specific and sensitive method for the detection of ONOO- in biological systems is significant. Herein, we reported a novel colorimetric and near-infrared fluorescent probe (pyridin-4-ylmethyl (Z)-2-cyano-2-(3-((E)-4-hydroxystyryl)-5,5-dimethylcyclohex-2-en-1-ylidene)acetate diphenyl phosphinate group (AN-DP)) based on isophorone and phosphinate groups for ONOO- detection. The probe displayed excellent selectivity toward ONOO- compared with other relevant analytes. It showed a good linear relationship between the fluorescence intensity at 670 nm and ONOO- concentration (0-10 µM) with a low detection limit (53 nM). Importantly, the probe was a colorimetric and near-infrared fluorescent probe suitable for ONOO- detection. Furthermore, the probe could be used for imaging ONOO- in HepG2 cells.

Long non­coding RNA LINC00312 regulates breast cancer progression through the miR­9/CDH1 axis.

Long non­coding RNAs (lncRNAs) are important mediators of the initiation and progression of tumors, including breast cancer (BC). The exact role of long intergenic non­coding RNA 00312 (LINC00312) in BC and its mechanism of action have not been reported to date. In the present study, LINC00312 was found to be downregulated in human BC tissues and cell lines by RT­qPCR. The findings of a functional study indicated that overexpression of LINC00312 suppressed the proliferation, colony forming ability, migration and invasiveness of BC cell lines. Mechanistically, LINC00312 was found to induce suppression of cell migration and invasion by directly binding to miR­9. Overexpression of LINC00312 increased the expression of cadherin 1 (CDH1), a direct target of miR­9, and decreased the expression of vimentin (VIM), a major cytoskeletal component of mesenchymal cells as determined by western blot analysis. miR­9 partly abrogated the upregulation of CDH1 and downregulation of VIM induced by LINC00312. Taken together, the results of the present study indicate a role for the LINC00312/miR­9/CDH1 axis in the progression of BC, and suggest a novel lncRNA­based diagnostic biomarker or therapeutic target for BC.

Iridoid glycosides from Morinda officinalis How. exert anti-inflammatory and anti-arthritic effects through inactivating MAPK and NF-κB signaling pathways.

BACKGROUND: The root of Morinda officinalis How. (MO, the family of Rubiaceae) has long been used to treat inflammatory diseases in China and other eastern Asian countries, and iridoid glycosides extracted from MO (MOIG) are believed to contribute to this anti-inflammatory effect. However, the mechanism underlying the anti-inflammatory and anti-arthritic activities of MOIG has not been elucidated. The aim of the present study was to determine how MOIG exerted anti-inflammatory and anti-arthritic effects in vivo and in RAW 264.7 macrophages. METHODS: MOIG were enriched by XDA-1 macroporous resin. The maximum feasible dose method was adopted to evaluate its acute toxicity. The analgesic effect of MOIG was evaluated by acetic acid writhing test and the anti-inflammatory effect was evaluated by cotton-pellet granuloma test in rats and air pouch granuloma test in mice. The anti-arthritic effect was evaluated by establishing an adjuvant arthritis model induced by Complete Freund's Adjuvant (CFA). The viability of the cultured RAW 264.7 macrophages was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. The anti-inflammatory activity was evaluated by measuring NO, IL-1ß, IL-6 and TNF-α levels in LPS-stimulated RAW 264.7 cells. The protein level of inflammatory responsive genes was evaluated by Western blot analysis. RESULTS: MOIG had no significant toxicity at maximum feasible dose of 22.5 g/kg. MO extracts and MOIG (50,100 and 200 mg/kg) all evoked a significantly inhibitory effects on the frequency of twisting induced by acetic acid in mice compared with the model control group. Administration of MO extracts and MOIG markedly decreased the dry and wet weight of cotton pellet granuloma in rats and air pouch granuloma in mice. MOIG significantly attenuated the paw swelling and decreased the arthritic score, weight loss, spleen index, and the serum level of inflammatory factors IL-1ß, IL-6 and IL-17a in CFA-induced arthritic rats. MOIG inhibited the production of inflammatory cytokines in LPS-stimulated RAW264.7 cells, and the expressions of iNOS, COX-2 and proteins related to MAPK and NF-κB signaling pathways in LPS-stimulated RAW 264.7 macrophages. CONCLUSION: MOIG exerted anti-inflammatory and anti-arthritic activities through inactivating MAPK and NF-κB signaling pathways, and this finding may provide a sound experimental basis for the clinical treatment of rheumatoid arthritis with MOIG.

Facile synthesis of MnO2-embedded flower-like hierarchical porous carbon microspheres as an enhanced electrocatalyst for sensitive detection of caffeic acid.

Tailored designs/fabrications of hierarchical porous advanced electrode materials are of great importance for developing high-performance electrochemical sensors. Herein, we demonstrate a simple and low-cost in situ chemical approach for the facile synthesis of MnO2-embedded hierarchical porous carbon microspheres (MnO2/CM). By the characterizations of scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction and energy dispersive spectroscopy, we evidenced that the synthesized product were flower-like carbon microspheres (CM) assembled by the bent flakes with thickness of about several nanometers and MnO2 nanorods were highly dispersed and successfully decorated on the CM layers, resulting in a rough surface and three-dimensional microstructure. The greatest benefit from the combined porous CM with MnO2 nanorods is that the MnO2/CM modified electrode has the synergetic catalysis effect on the electro-oxidation of caffeic acid, leading to the remarkable increase in the electron transfer rate and significant decrease in the over-potential for the caffeic acid oxidation in contrast to the bare electrode and CM modified electrode. This implies that the prepared MnO2/CM can be employed as an enhanced electrocatalyst for the sensitive detection of caffeic acid. Under the optimum conditions, the anodic peak current of caffeic acid is linear with its concentration in the range of 0.01-15.00 µmol L-1, and a detection limit of 2.7 nmol L-1 is achieved based on S/N = 3. The developed sensor shows good selectivity, sensitivity, reproducibility, and also excellent recovery in the detections of real samples, revealing the promising practicality of the sensor for the caffeic acid detection.

Ag/N-doped reduced graphene oxide incorporated with molecularly imprinted polymer: An advanced electrochemical sensing platform for salbutamol determination.

In this work, the metallic silver and non-metallic nitrogen co-doped reduced graphene oxide (Ag-N-RGO) was first synthesized by a simple and cost-effective strategy, and then a molecularly imprinted polymer (MIP) was formed in situ at the surface of the prepared composite via electropolymerization of o-phenylenediamine in the presence of salbutamol as the template molecule. The electrochemical characterizations demonstrate that the bifunctional graphene-based composite shows improved catalytic performance than that of pristine graphene doped with one-component or none. The MIP sensor based on Ag-N-RGO owns high porous surface structure, resulting in the increased current response and enhanced recognition capacity than that of non-imprinted sensor. The outstanding performance of the developed sensor derives from the combined advantages of Ag-N-RGO with effective catalytic property and MIP with excellent selectivity. Under the optimal conditions, the electrochemical response of the developed sensor is linearly proportional to the concentration of salbutamol in the range of 0.03-20.00µmolL-1 with a low detection limit of 7 nmol L-1. The designed sensor has exhibited the multiple advantages such as low cost, simple manufacture, convenient use, excellent selectivity and good reproducibility. Finally, the proposed method has been extended for the determinations of salbutamol in human urine and pork samples, and the satisfactory recoveries between 98.9-105.3% are achieved.

Expression and significance of glucose transporter-1, P-glycoprotein, multidrug resistance-associated protein and glutathione S-transferase-π in laryngeal carcinoma.

Increasing glucose transporter-1 (GLUT-1) activity is one of the most important ways to increase the cellular influx of glucose. We previously demonstrated that increased GLUT-1 expression was an independent predictor of survival in patients with laryngeal carcinoma. Thus, GLUT-1 may present a novel therapeutic target in laryngeal carcinoma. In this study, the expression of GLUT-1, P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1) and glutathione S-transferase-π (GST-π) in laryngeal carcinomas was investigated by immunohistochemistry. Additionally, possible correlations between GLUT-1 and P-gp, MRP1 and GST-π and various clinicopathological parameters were analyzed. In this study, 52.9% (18/34), 58.8% (20/34), 20.6% (7/34) and 58.8% (20/34) of the laryngeal carcinomas were positive for GLUT-1, P-gp, MRP1 and GST-π, respectively. The expression of GLUT-1, P-gp, MRP1 and GST-π was higher in laryngeal carcinoma specimens when compared with laryngeal precancerous lesions (P<0.05). Pearson's correlation analysis showed correlations between GLUT-1 and P-gp (r=0.364; P=0.034), GLUT-1 and MRP1 (r=0.359; P=0.037) and P-gp and GST-π (r=0.426; P=0.012). GLUT-1 expression was found to significantly correlate with tumor-node-metastasis classification (P=0.02) and clinical stage (P=0.037). Furthermore, P-gp was found to significantly correlate with clinical stage (P=0.026). Univariate analysis showed that MRP1 expression was significantly associated with poor survival (c2=5.16; P=0.023). Multivariate analysis revealed that lymph node metastasis (P=0.009) and MRP1 overexpression (P=0.023) were significant predictors of poor survival. In the present study, the expression of GLUT-1, P-gp, MRP1 and GST-π in laryngeal carcinomas was investigated, as well as the correlations between these proteins. P-gp was found to significantly correlate with clinical stage, while MRP1 overexpression was significantly associated with poor survival.