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Garcinia xanthochymus is a climax tree species growing in the Xishuangbanna tropical rainforests, which possesses a unique adaptation mechanism to the tropical monsoon climate, i.e., its seeds mature at the end of the rainy season and shed, mostly do not germinate until next rainy season, distinctly differing from most other climax species there. This study investigated the morphological structure, desiccation tolerance, and germination characteristics of G. xanthochymus seeds to understand their cytological basis and ecological adaptation. It was found that G. xanthochymus seeds germinate when incubated at temperatures between 20 and 35 °C, with a thermal optimum of 30 °C, but have a short period of dormancy (> 40 days even at 30 °C). The seeds were intolerant to desiccation, and completely lost viability when desiccated to 25% miosture content (fresh weight basis), exhibiting typical recalcitrant seed traits. However, they also possessed strong desiccation resistance, maintaining approximately 33% misture content and 50% viability even after 20 days of silica gel drying. Until germination, G. xanthochymus seeds did not exhibit visible structural differentiation. They are composed of a cluster of uniformly shaped, shallowly differentiated parenchymal cells possessing embryonic and storage functions. Thus, they germinate totipotently and can regenerate into seedlings even after being subjected to various cutting, which protects them from animal grazing. This explains how G. xanthochymus seeds withstand biotic and abiotic stresses during the dry season in Xishuangbanna, meanwhile implys that G. xanthochymus is more dependent on the forest environment and more sensitive to habitat changes. [ABSTRACT FROM AUTHOR]

A new fluorescence sensing strategy has been developed. Four bimetallic nanoclusters, gold/silver, gold/copper, gold/molybdenum and gold/cobalt, were prepared using bovine serum albumin (BSA) as a reducing and stabilizing agent. The fluorescence properties of four nanoclusters were explored by solid-state UV and XPS. The gold/silver nanoclusters (BSA-Au/Ag NCs) with the best ratiometric fluorescence properties for gallic acid (GA) in plants were selected to realize the sensitive detection of GA. GA affected the conformation of BSA, thereby disrupting the luminescent environment of the nanoclusters, resulting in a pronounced fluorescence quenching at 566 nm. The ratiometric fluorescence signal (I566/I453) was used for trace detection of GA in plants. It has a wide response range of 1.25–40.0 μM and a low detection limit of 45.27 nM. GA was detected at 19.49 μM in the plant extract, and the spiked recoveries ranged from 96.09 to 104.6%. In addition, due to the non-toxic and biocompatible properties of BSA, BSA-Au/Ag NCs have also been validated for fluorescence imaging of plant tissues. It realized the comparison of GA content in different parts of plants and the difference of GA content in plants after abiotic stress. Therefore, the developed strategy offers potential application for the analytical study of active substances in plants. [ABSTRACT FROM AUTHOR]

Spontaneous subarachnoid hemorrhage (SAH) accounts for approximately 5% of all cases of stroke. SAH is correlated with elevated rates of mortality and disability. Despite significant advancements in comprehending the pathogenesis and surgical management, efficacious clinical interventions remain restricted, and the prognosis is yet to be enhanced. MicroRNAs play a crucial role in various pathological processes in organisms. Revealing these regulatory processes is conducive to the development of new treatment methods. MicroRNA-124 is highly expressed in the nervous system and has significant research value for SAH. This study aims to explore the role of miR-124 in the early post-SAH period on neural function and verify whether it is involved in the pathological and physiological processes of SAH. In this study, we used methods such as comparing the expression levels of miR-124 in cerebrospinal fluid, establishing a rat SAH model, and a mouse embryonic primary neuron hemoglobin stimulation model to verify the downstream proteins of miR-124 in SAH. Through transfection techniques, we adjusted the expression of this small RNA in Vitro and in Vivo models using miR-124 inhibitor and mimic in the primary neuron hemoglobin stimulation model and rat SAH model, and observed the phenotype. Finally, by consulting the literature and verifying in Vivo and in Vitro methods, AK4 and downstream molecule ATF3 were identified as downstream targets of miR-124. [ABSTRACT FROM AUTHOR]

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Plant invasion causes changes in floristic composition, and structural and functional degradation of tropical rainforest, which is driven by global changes, deforestation and habitat fragmentation, with temperature increasing as a marked trait in rainforest remnants. Here, we hypothesized that microclimate change, particularly increased temperature, is a major driver for plant invasion to tropical rainforest. Laboratory and field experiments were designed to investigate the germination ecology and high-temperature tolerance of intermediate seeds from three species: Cinnamomum burmanni, Citrus maxima, and Coffea arabica, which are cultivated in Xishuangbanna, tropical China though not native. It was found that the seeds all exhibited sensitivity to high-temperature, including low germination when incubated at ≥ 35 °C or ≥ 9 h daily warm period at 40 °C, and viability loss after ≥ 4 d continuous heating at 40 °C or 30-min heating at temperature ≥ 50 °C, although with interspecific variations. Meanwhile, these species demonstrated a strong preference for forest habitats during plant regeneration from seeds, including higher germination percentage and longer seeds and seedling survival under forest conditions. Overall, intermediate seeds had high-temperature sensitivity, close to or slightly lower than recalcitrant seeds, but markedly higher than orthodox seeds of pioneer and weed species previously reported. We suggest that Cinnamomum burmanni, Citrus maxima, and Coffea arabica all have the potential to enter Xishuangbanna tropical rainforests. [ABSTRACT FROM AUTHOR]

Purpose: Tumor immunotherapy has the advantages of high specificity, minimal damage to the patient's body, and a long-lasting anti-tumor effect. However, due to the existence of immune escape phenomenon, the effect of anti-tumor immunotherapy is still poor. Therefore, a cancer vaccine that reverses tumor-associated immunosuppression is a very promising approach for research and treatment. Methods: Vaccines were prepared using autologous and allogeneic tumor cells and their lysates to syngeneic tumor cell lysates as immunogens. The glioma cell proliferation, apoptosis and the secretion level of MCP-2, IFN-γ were detected to evaluate the efficacy of this treatment against glioma in vitro. In addition, a rat glioma model was established to investigate the anti-tumor effect in vivo, and evaluated its efficacy by observing the changes of CD4 + T cells, CD8 + T cells, NK cells, and the level of IL-2 and IL-10 in peripheral blood before and after treatment. Results: The C6 + 9L glioma cell lysate vaccine (C6 + 9L-CL) not only inhibited the proliferation of glioma cells and promoted their apoptosis in vitro, but also significantly inhibited the tumor growth in vivo and improved the survival time of rats. In addition, the C6 + 9L-CL vaccine enhanced the anti-tumor immune response by promoting the secretion of T cell chemokines MCP-2, IFN-γ and IL-2, and by stimulating the proliferation of T cells and NK cells in peripheral blood and glioma tissues. Conclusion: Our findings demonstrate the inhibitory effect of molecular mimic vaccines on glioma and provided a theoretical basis for molecular mimic hybrid vaccines as a potential therapeutic approach. [ABSTRACT FROM AUTHOR]

The interactions between optical solitons have obviously effects on the capacity and quality of communication systems, which will lead to the waveform distortion, deterioration of transmission characteristics, reduction in transmission rate and shortening of the transmission distance. In this paper, we will discuss the optical soliton interactions and reduce their interactions to improve the communication quality. The analytic two soliton solutions are derived based on the bilinear method. Four kinds of interactions between optical solitons are analyzed, and the reasons for reducing the interactions between them are obtained. The conclusions of this paper are helpful to enhance the communication quality and provide theoretical support for nonlinear control methods in nonlinear optical systems. [ABSTRACT FROM AUTHOR]

Purpose: The poor outcomes in glioblastoma necessitate new therapeutic target. Isoprenylcysteine carboxyl methyltransferase (ICMT), a unique enzyme of the final step of prenylation that modifies activities of oncogenic proteins, represents a promising target for many cancers. Methods: Expression pattern, function and downstream pathway of ICMT in glioblastoma were analyzed using immunohistochemistry, ELISA, cellular assays and immunoblotting method. Combinatory effect was analyzed using Chou-Talalay approach. Results: Upregulation of ICMT expression is a common phenomenon in glioblastoma patients regardless of clinicopathological characteristics. Gain-of-function and loss-of-function analysis support the role of ICMT in glioblastoma growth and survival but not migration. Importantly, pharmacological inhibitors of ICMT are effectively against glioblastoma cells while sparing normal neuron cells, and furthermore that they act synergistically with chemotherapeutic drugs. Consistently, ICMT inhibitor UCM-1336 significantly inhibits glioblastoma growth without causing toxicity in mice. Mechanistic studies demonstrate that Ras/Raf/Mek/Erk rather than Ras/PI3K/Akt/mTOR is the downstream pathway of ICMT-mediated glioblastoma growth. Conclusions: Our findings provide the proof-of-concept of pharmacologically targeting ICMT in the treatment of glioblastoma via deactivation of Ras/Raf/Mek/Erk. [ABSTRACT FROM AUTHOR]

A synthesis route of using cellulose as the precursor to prepare porous carbon (PC) had been established in this study. The as-prepared PC was introduced as carriers in the synthesis process of porous carbon-molecularly imprinted polymers (PC-MIPs), which greatly improved the absorption capacity of MIPs. Triazine pesticides in corn were extracted with matrix solid-phase dispersion (MSPD) using the PC-MIPs as dispersants and determined by ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Under the optimal MSPD condition for extracting six kinds of triazines (simazine, terbutryn, simetryne, prometryne, ametryn, and atrazine), the detection limits were 0.005–0.02 ng g−1, while the precisions were 1.2–5.9%, and the recoveries were 92.6–104.7%. The method has been extensively applied to analyze various corn samples. Atrazine residue (1.2 μg kg−1) was detected in one corn sample, which was lower than the maximum residual limit indicated by the Chinese stated standards (50 μg kg−1). [ABSTRACT FROM AUTHOR]

A new type of ratiometric molecularly imprinted fluorescence probe (B-CQDs@Eu/MIPs) based on biomass carbon quantum dots (B-CQDs) and europium ions (Eu3+) has been prepared to recognize and detect tetracycline (TC). In the experiment, the fluorescent material B-CQDs were prepared using passion fruit peels through microwave-assisted method, which by the meantime achieves the reuse of biomass waste. TC can block the transition of some parts of electrons in the prepared B-CQDs from the excited state to the ground state, resulting in the weakening of its blue light (Ex = 394 nm, Em = 457 nm), while TC can be chelated by Eu3+ and emit red characteristic fluorescence (Ex = 394 nm, Em = 620 nm) due to the antenna effect. Thus, a ratiometric fluorescence response to TC is the result of the combined B-CQD and Eu3+. Based on this, we established the ratiometric fluorescent molecularly imprinted (MIP) probe for the detection of TC. The prepared B-CQDs@Eu/MIPs is aimed at catching the fluorescence changes of target tetracycline (TC) sensitively with the special combination of the specific recognition cavities and TC. The linear fluorescence quenching range of TC in milk using the fluorescent probe was 25–2000 nM, and the detection limit was 7.9 nM. The recoveries of this method for TC were 94.2–103.7%, and the relative standard deviations (RSDs) were 1.5–5.3%. Owing to the predetermined nature of MIP technology and the special response of ratio fluorescence, the interference of common substances is eliminated completely, which greatly improved the selectivity of its practical applications. [ABSTRACT FROM AUTHOR]

A sensitive and effective strategy for the detection of cytochrome c (Cyt c) and trypsin was developed using biomass nitrogen-doped carbon quantum dots (N-CQDs) as the fluorescence probe. N-CQDs were synthesized through a one-pot hydrothermal method by utilizing cellulolytic enzyme lignin as the carbon source and ammonia as the solvent and nitrogen source. The obtained N-CQDs had good water solubility and stable optical properties. The introduction of nitrogen increased fluorescence quantum yield (QY) to 8.23%, which was almost four times as high as that before nitrogen doping. The N-CQDs were fabricated as a label-free biosensor to detect Cyt c and trypsin. The fluorescence of N-CQDs was quenched with positively charged Cyt c due to electrostatic induction aggregation and static quenching. However, Cyt c tended to be hydrolyzed into small peptides in the presence of trypsin, which caused fluorescence recovery of the N-CQDs/Cyt c complex. A wide linear response range was achieved for Cyt c within 1–50 μM and the developed N-CQDs/Cyt c complex displayed a linear response for trypsin within 0.09–5.4 U/mL. The detection limits were 0.29 μM for Cyt c and 0.013 U/mL for trypsin, respectively. Furthermore, this assay had been applied to Cyt c and trypsin detection in serum samples with the recoveries in the range of 94.6–98.5% and 95.5–102.0%, respectively. The established method was sensitive, selective, easy to operate, and low cost, which proved its potential application in clinical diagnosis. [ABSTRACT FROM AUTHOR]

Objective: microRNAs (miRNAs) play critical roles in embryogenesis, cell differentiation and the pathogenesis of several human diseases, including systemic lupus erythematosus (SLE). Toll-like receptors (TLRs) are also known to exert crucial functions in the immune response activation occurring in the pathogenesis of autoimmune diseases like SLE. Herein, the current study aimed to explore the potential role of miR-152-3p in TLR-mediated inflammatory response in SLE. Methods: We determined the miR-152-3p expression profiles in CD4+ T cells and peripheral blood mononuclear cells (PBMCs) harvested from patients with SLE and healthy controls, and analyzed the correlation between miR-152-3p expression and clinicopathological parameters. CD70 and CD40L expression patterns in CD4+ T cells were assessed by RT-qPCR and flow cytometry. ChIP was adopted to determine the enrichment of DNA methyltransferase 1 (DNMT1) in the promoter region of myeloid differentiation factor 88 (MyD88). Results: The obtained findings revealed that miR-152-3p was highly-expressed in CD4+ T cells and PBMCs of patients with SLE, and this high expression was associated with facial erythema, joint pain, double-stranded DNA, and IgG antibody. DNMT1 could be enriched in the MyD88 promoter, and miR-152-3p inhibited the methylation of MyD88 by targeting DNMT1. We also found that silencing miR-152-3p inhibited MyD88 expression not only to repress the autoreactivity of CD4+ T cells and but also to restrain their cellular inflammation, which were also validated in vivo. Conclusion: Our study suggests that miR-152-3p promotes TLR-mediated inflammatory response in CD4+ T cells by regulating the DNMT1/MyD88 signaling pathway, which highlights novel anti-inflammatory target for SLE treatment. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to investigate the feasibility of segmentation-independent volume rendering (SI-VR) in visualising the root entry zone (REZ), and to explore the influence on the management of vascular compression syndromes (VCSs).Methods: Two hundred and twenty patients with VCSs were recruited in this prospective study from July 2015 to May 2019. SI-VR was reconstructed based on inverted 3D fast spin echo T2WI. They were assigned to the experimental group and control group randomly. Patients in the experimental group would accept extra evaluation based on SI-VR before microvascular decompression. Image quality and diagnostic accuracy between SI-VR and 3D fast spin echo T2WI in the experimental group were compared by Mann-Whitney U test and chi-square test, separately. Interobserver agreement was performed with intraclass correlation coefficient. Postsurgical outcomes and complications between two groups were compared by chi-square test.Results: SI-VR had a better interobserver agreement (0.82 vs 0.68) and diagnostic accuracy (95.5% vs 83.6%, p = 0.004) than that of 3D fast spin echo T2WI. Especially, significantly improved diagnostic accuracy was reached in detecting the multi-vascular branches compression (100% vs 15.4%, p < 0.001). There were fewer complications (7.1% vs 26.8%, p = 0.004) and less operation time (20.7 min vs 14.5 min, p = 0.007) but no significant difference of pain relief (p = 0.19) in the experimental group than in the control group.Conclusions: The SI-VR method is feasible for the precise demonstration of the anatomy structure along the REZ, with high reliability and reproducibility. Unbiased pre-surgical visualisation could reduce redundant explorations and post-surgical complications in patients who undergo microvascular decompression.Key Points: • Visualisation of the root entry zone by the segmentation-independent volume rendering is in accordance with the landscape by the neuro-endoscopy. • Segmentation-independent volume rendering has an advantage over 3D fast spin echo T2WI in the visualisation of multi-vascular branches compression. • Presurgical 3D visualisation of the neurovascular compression at the root entry zone leads to less postsurgical complications from the decrease of redundant exploration. [ABSTRACT FROM AUTHOR]

Purpose: Multi-syphilitic gummas in pituitary and cerebellopontine angle (CPA) are extremely rare and easily misdiagnosed especially in patients with antibiotic abuse. We write this paper for clinicians to better understanding of cerebral gumma. Methods: We report a patient with syphilitic gummas in pituitary and left CPA. The definite diagnosis is made by histopathology after surgery. Results: A 49-years-old woman suffered from headaches with tinnitus and hypoacusis in left ear. She was diagnosed with syphilis but untreated. There were no chancre and rashes in the course of disease. Syphilis serological tests were positive. Brain MRI found two masses located in the left CPA and hypophysial fossa. The two masses were removed successively. We found a large number of Treponemapallidum in paraffin-embedded specimens by immunohistochemical staining. Conclusions: Syphilitic gummas in pituitary and CPA are similar to benign or malignant brain tumors, easily leading to misdiagnosis. Gumma should be considered in differential diagnosis when a patient has unexplained nervous system symptoms or signs and imaging findings suggest intracranial mass in syphilis seropositive patients. [ABSTRACT FROM AUTHOR]

A method for determination of sulfonylurea herbicides (SUHs) in grain was developed by using mesoporous structured molecularly imprinted polymers (M-MIPs) as adsorbents of matrix solid-phase dispersion (MSPD) extraction, coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this method, M-MIPs were synthesized by selecting chlorimuron-ethyl as template molecule, cetyltrimethylammonium bromide as mesoporous structure directing agent, 3-aminopropyltriethoxysilane as functional monomer, and tetraethyl orthosilicate as crosslinker. Then, M-MIPs were characterized by diverse instrumental techniques, absorption characteristics of M-MIPs were studied, and the experimental conditions for the MSPD extraction were optimized. MSPD enabled extraction and clean-up steps to be completed simultaneously. The M-MIPs with mesoporous structure improved detection selectivity, increased adsorptive capacity, and accelerated adsorption rate. Under the best conditions, excellent linearity of SUHs was obtained in the range of 0.25–25 μg kg−1, the determination limits of chlorimuron-ethyl, nicosulfuron, thifensulfuron-methyl and chlorsulfuron were 0.075, 0.069, 0.083, and 0.105 μg kg−1, respectively. The relative standard deviations were less than 5.5%. [ABSTRACT FROM AUTHOR]

A novel fluorescent probe based on molecularly imprinted polymers (MIPs) coupled with carbon quantum dots (CQDs) was fabricated and successfully used for selective recognition of mesotrione. In this probe, the biomass-derived CQDs were prepared through a hydrothermal method using mango peels as carbon source, and the whole synthesis procedure was green without chemical reagents. The CQDs were encapsulated into MIPs by using sol-gel technology. After removal of the template molecule mesotrione, specific binding sites are formed and there is electrostatic attraction between the probe and the template molecule. The synthetic CQDs@MIPs were able to selectively capture the target mesotrione with fluorescence quenching via the specific interaction between mesotrione and the recognition cavities. The probe was used for determination of mesotrione in corn to verify the practicality of the proposed method. The detection limit of mesotrione was 4.7 nmol L−1, and the linear range was 15 nmol L−1 to 3000 nmol L−1. Meanwhile, the recoveries of this method for mesotrione were 91.4–96.2%, and the relative standard deviations (RSDs) were 3.2–6.1%. This work provides a novel research method to synthesize CQDs@MIPs with high selectivity (imprinting factor = 5.6), and which can be used for convenient, rapid recognition and sensitive detection of trace compounds from complex matrices. [ABSTRACT FROM AUTHOR]

Metal organic frameworks-molecular imprinting polymers (MOFs-MIPs) were applied as dispersants of matrix solid phase dispersion (MSPD) followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) to selectively analyze pyrethroids in wheat. MOFs-MIPs characterized by a series of instrumental techniques and the adsorption properties researched by isothermal, kinetics, thermodynamics, and selective binding experiments. The results revealed that the MOFs-MIPs had a larger adsorption capacity (474.56 mg g−1) and fast adsorption time (20 min). What is more, MOFs-MIPs-MSPD procedure clearly increased extraction efficiency and decreased the consumption of organic solvent. The better recoveries of pyrethroids were reached by optimizing MSPD conditions. Under the excellent conditions, the linearity ranges of pyrethroids in wheat samples were obtained varying from 10 to 1000 ng g−1; the limits of detection were in the range of 1.8-2.8 ng g−1 and the precisions were lower than 6.3%. At the same time, the method was successfully applied for detection of three pyrethroids residue in six kinds of wheat samples and cyhalothrin residue detected in one wheat was 23.96 ng g−1, which is lower than the maximum residue limits allowed by the Ministry of Agriculture of the People's Republic of China. The developed MOFs-MIPs-MSPD-GC-MS/MS method displayed high selectivity, absorbability, simplicity, rapidity, sensitivity, and excellent practical food control applicability. [ABSTRACT FROM AUTHOR]

Subarachnoid hemorrhage (SAH) is a neurologically destructive stroke in which early brain injury (EBI) plays a pivotal role in poor patient outcomes. Expanding upon our previous work, multiple techniques and methods were used in this preclinical study to further elucidate the mechanisms underlying the beneficial effects of apolipoprotein E (ApoE) against EBI after SAH in murine apolipoprotein E gene-knockout mice (Apoe−/−, KO) and wild-type mice (WT) on a C57BL/6J background. We reported that Apoe deficiency resulted in a more extensive EBI at 48 h after SAH in mice demonstrated by MRI scanning and immunohistochemical staining and exhibited more extensive white matter injury and neuronal apoptosis than WT mice. These changes were associated with an increase in NADPH oxidase 2 (NOX2) expression, an important regulator of both oxidative stress and inflammatory cytokines. Furthermore, immunohistochemical analysis revealed that NOX2 was abundantly expressed in activated M1 microglia. The JAK2/STAT3 signaling pathway, an upstream regulator of NOX2, was increased in WT mice and activated to an even greater extent in Apoe−/− mice; whereas, the JAK2-specific inhibitor, AG490, reduced NOX2 expression, oxidative stress, and inflammation in Apoe-deficient mice. Also, apoE-mimetic peptide COG1410 suppressed the JAK2/STAT3 signaling pathway and significantly reduced M1 microglia activation with subsequent attenuation of oxidative stress and inflammation after SAH. Taken together, apoE and apoE-mimetic peptide have whole-brain protective effects that may reduce EBI after SAH via M1 microglial quiescence through the attenuation of the JAK2/STAT3/NOX2 signaling pathway axis. [ABSTRACT FROM AUTHOR]

A new fluorescent probe based on graphitic carbon nitride (g-C3N4) combined with molecularly imprinted silica was successfully fabricated and used to selectively recognize chlortetracycline (CTC). The g-C3N4 used in this study has the characteristics of low toxicity and high chemical stability. This synthetic composite was characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, UV spectroscopy, X-ray diffraction, and fluorescence spectroscopy. The material was used to detect CTC by the fluorescence quenching technique. The fluorescence quenching was due to g-C3N4 and the benzene ring of CTC through π-π electron donor-acceptor interaction and electrostatic force. Hydrogen bonds formed between CTC and 3-aminopropyltriethoxysilane during the polymerization process. Eventually, a considerable amount of selective recognition holes were formed in the composite material and could specifically recognize the template molecule CTC. In addition, the probe strategy was successfully applied to milk analysis, and the recoveries ranged from 90.1% to 95.7%, with relative standard deviations of 1.8-2.8%; the detection limit for CTC was 8 ng mL-1. The results indicate that this method combined the sensitivity of fluorescence detection with the excellent selectivity of a molecularly imprinted polymer. The new material can be widely used in the detection of dairy products.Schematic of synthesis of the MIP-capped g-C3N4 by sol-gel reaction [ABSTRACT FROM AUTHOR]

The concentration of L-cysteine (Cys) and glutathione (GSH) is closely related to the critical risk of various diseases. In our study, a new rapid method for the determination of Cys and GSH in water and urine samples has been developed using a fluorescent probe technique, which was based on crystal violet (CV)-functionalized CdTe quantum dots (QDs). The original QDs emitted fluorescence light, which was turned off upon adding CV. This conjugation of CV and QDs could be attributed to electrostatic interaction between COO of mercaptopropionic acid (MPA) on the surface of QDs and N of CV in aqueous solution. In addition, Förster resonance energy transfer (FRET) also occurred between CdTe QDs and CV. After adding Cys or GSH to the solution, Cys or GSH exhibited a stronger binding preference toward Cd than Cd-MPA, which disturbed the interaction between MPA and QDs. Thus, most MPA was able to be separated from the surface of QDs because of the participation of Cys or GSH. Then, the fluorescence intensity of the CdTe QDs was enhanced. Good linear relationships were obtained in the range of 0.02-40 μg mL and 0.02-50 μg mL, and the detection limits were calculated as 10.5 ng mL and 8.2 ng mL, for Cys and GSH, respectively. In addition, the concentrations of biological thiols in water and urine samples were determined by the standard addition method using Cys as the standard; the quantitative recoveries were in the range of 97.3-105.8%, and relative standard deviations (RSDs) ranged from 2.5 to 3.7%. The method had several unique properties, such as simplicity, lower cost, high sensitivity, and environmental acceptability. [ABSTRACT FROM AUTHOR]

The authors describe an efficient method for the extraction of tetracycline antibiotics (TCs) from water samples by using a new kind of core-shell adsorbent. It consists of a magnetite (FeO) core and a metal-organic framework (type ZIF-8) as the shell. The sorbent has a large specific surface and superparamagnetic response. The sorbent was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, nitrogen adsorption, and X-ray diffraction. The adsorption isotherms, dynamic adsorption, and mechanisms of interactions between tetracycline and sorbent were studied. Various parameters affecting the extraction efficiency were optimized. Following desorption of the TCs with methanol (containing 1% of acetic acid), they were quantified by using ultra-high performance liquid chromatography combined with mass spectrometry. The method has a linear range that extends from 0.5 to 50 ng·L, and the limits of detection for tetracycline, chlortetracycline, and oxytetracycline are 0.125, 0.122 and 0.143 ng·L, respectively. The relative standard deviations of intra-day and inter-day assays range from 3.3% to 8.5%, and from 2.8% to 8.3%, respectively. The recoveries of TCs (at spiking levels of 0.5, 5.0 and 50 ng·L) are in the range between 78.3% and 93.7%. The method was successfully applied to the determination of TCs in spiked river water, fish pond water, and livestock wastewater. [ABSTRACT FROM AUTHOR]

This research investigates the main factors influencing changes in hydrogen concentration in a fault zone and analyzes the relationship between hydrogen and tectonic activity. Based on the hydrogen concentration in the fault gas and continuous observation data from Mashankou, Neixiang County, Henan Province, the relationships between the variation in hydrogen concentration and ground temperature, atmospheric temperature, and atmospheric pressure are analyzed. In addition, the earth tide effect on hydrogen in the fault zone is discussed. The results show that the direct influence of atmospheric or ground temperatures on the hydrogen concentration is not significant. The atmospheric and ground temperatures have some impact on the hydrogen concentration only when ground temperature increases. By means of a wavelet analysis method, which separates the semidiurnal wave and diurnal wave signals of hydrogen, the results show that the hydrogen concentration is capable of indicating the solid earth tide when comparing the pressure tide and solid earth tide signals in the same period. [ABSTRACT FROM AUTHOR]

In this work, a simple and selective method based on matrix solid phase dispersion (MSPD) using molecularly imprinted polymers (MIPs) as sorbents was successfully developed for the determination of melamine (MEL) in milk powder. The MIPs have been prepared by surface imprinted polymerization method using carbon nanotube (CNT) as support, MEL as template molecule, γ-aminopropyltriethoxysilane as functional monomer, and tetraethyl orthosilicate as cross-linking agent. The MIPs were characterized by Fourier transform infrared spectrometer and scanning electron microscopy. At the same time, the adsorption isotherm, dynamic adsorption, and selective adsorption of MIPs to MEL were also studied. The prepared MIPs were used as dispersant of MSPD to extraction and separate MEL in milk powder. We optimized the extraction conditions as follows: the ratio of MIPs to sample was 2:3; the dispersion time was 10 min; washing solvent was 2.0 mL acetonitrile; and elution solvent was 4.0 mL ammonium methanol (5:95, v/ v). Once the MSPD process was completed, the MEL extracted from milk powder was determined by LC-MS/MS. Under the optimal conditions, the limit of detection of MEL was 0.2 ng g. The relative standard deviations of intra-day and inter-day were obtained in the range of 0.4∼5.1 %. The satisfied recoveries of MEL were 92.5∼97.2 %. The MIP-MSPD method has some advantages, such as higher selectivity, lower cost of preparation, less time consuming and organic solvent consumption, simpler sample pretreatment procedure, and higher extraction recovery compared with those existing methods which were used for determination of MEL. [ABSTRACT FROM AUTHOR]

Purpose: Ruthenium complex is a potentially theranostic agent for cancer imaging and therapy, however its application is limited due to poor water-solubility and lack of tumor selectivity. To overcome the above drawbacks, pH-sensitive nanocapsule as a novel targeting carrier was designed to deliver ruthenium complex for treating xenograft tumor of mice. Methods: The core/shell structured nanocapsule with ruthenium complex tris(1,10-phenanthroline) ruthenium(II) complex (3P-Ru) as the core and a pH-sensitive polymeric material poly (2-diisopropylaminoethyl methacrylate)-block poly(2-aminoethyl methacrylate hydrochloride) (PbPS) as the shell was synthesized and characterized. Meanwhile, the nanocapsule was used to investigate cell viability and evaluate tissue distribution as well as preventing tumor growth efficacy in U251 stem cells tumor-bearing mouse model. Results: The nanocapsule had a size of 103.1 ± 11.3 nm, zeta potential of -40 ± 5.3 mV, EE of 76.7 ± 0.9%, LE of 25.4 ± 0.6% and it could control drug release under different pH conditions. The results of cell uptake showed that the fluorescent 3P-Ru loaded in the nanocapsule could be delivered into cells with high efficiency, and then significantly inhibited U251 proliferation in a concentration-dependent manner. After U251 stem cells were transplanted subcutaneously into mice, the 3P-Ru/PbPS nanocapsule (PbPS-Ru-NC) via intravenous administration could concentrate in tumor area and obviously prevent tumor growth. Conclusions: The pH-sensitive nanocapsule as a antitumor agent carrier was able to effectively deliver 3P-Ru into gliomas cells, and cell growth was significantly inhibited both in vitro and in vivo. Such pH-sensitive nanocapsule for ruthenium complex delivery would have great potential application in tumor theranostics. [ABSTRACT FROM AUTHOR]

This study investigates the refined simulation skill that results when the regional Climate extension of the Weather Research and Forecasting (CWRF) model is nested in the ECMWF Hamburg version 4.5 (ECHAM) atmospheric general circulation model over the United States during 1980-2009, where observed sea surface temperatures are used in both models. Over the contiguous US, for each of the four seasons from winter to fall, CWRF reduces the root mean square error of the ECHAM seasonal mean surface air temperature simulation by 0.19, 0.82, 2.02 and 1.85 °C, and increases the equitable threat score of seasonal mean precipitation by 0.18, 0.11, 0.09 and 0.12. CWRF also simulates much more realistically daily precipitation frequency and heavy precipitation events, typically over the Central Great Plains, Cascade Mountains and Gulf Coast States. These CWRF skill enhancements are attributed to the increased spatial resolution and physics refinements in representing orographic, terrestrial hydrology, convection, and cloud-aerosol-radiation effects and their interactions. Empirical orthogonal function analysis of seasonal mean precipitation and surface air temperature interannual variability shows that, in general, CWRF substantially improves the spatial distribution of both quantities, while temporal evolution (i.e. interannual variability) of the first 3 primary patterns is highly correlated with that of the driving ECHAM (except for summer precipitation), and they both have low temporal correlations against observations. During winter, when large-scale forcing dominates, both models also have similar responses to strong ENSO signals where they successfully capture observed precipitation composite anomalies but substantially fail to reproduce surface air temperature anomalies. When driven by the ECMWF Reanalysis Interim, CWRF produces a very realistic interannual evolution of large-scale precipitation and surface air temperature patterns where the temporal correlations with observations are significant. These results indicate that CWRF can greatly improve mesoscale regional climate structures but it cannot change interannual variations of the large-scale patterns, which are determined by the driving lateral boundary conditions. [ABSTRACT FROM AUTHOR]

A novel dual-function material was synthesized by anchoring a molecularly imprinted polymer (MIP) layer on Mn-doped ZnS quantum dots (QDs) via a sol-gel process using 3-aminopropyltriethoxysilane (APTES) as a functional monomer, tetraethoxysilane (TEOS) as cross-linker, and nicosulfuron as template through a surface imprinting method. The amino groups in the APTES interact with the functional groups in the template molecules to form a complex through hydrogen bonding. The energy of the QDs was transferred to the complex, resulting in the quenching of the QDs and thus decreasing the fluorescence intensity, which allowed the nicosulfuron to be sensed optically. Fluorescence intensity from MIP-coated QDs was more strongly quenched by nicosulfuron than that of the non-imprinted polymer, which indicated that the MIP-coated QDs which acted as a fluorescence probe could selectively recognize nicosulfuron. Under the optimal conditions, it can detect down to 1.1 nmol L of nicosulfuron, and a linear relationship has been obtained covering the concentration range of 12-6000 nmol L. The recoveries were in the range from 89.6 to 96.5 %, and the relative standard deviations were in the range of 2.5-5.7 %. The present study established a new strategy to combine inorganic (Mn-doped ZnS QDs)-organic MIPs, which is successfully applied to determine nicosulfuron in water samples. [ABSTRACT FROM AUTHOR]

A fast and economical method has been developed for the preconcentration of the carbamates propoxur, pirimicarb and promecarb by using magnetic molecularly imprinted polymers (m-MIPs). Propoxur was applied as the template for the analytes, and carbon nanotubes as a supporting template. The effects of the amount of magnetic sorbent, shaking time and rate, eluting solution on the extraction efficiency were studied. The processes of adsorption and desorption occur within 25 min, and the m-MIPs can be collected by applying an external magnetic field within 15 s. The m-MIPs were characterized by using FTIR, transmission electron microscopy, and with a vibrating sample magnetometer. The pesticides were quantified by HPLC with UV detection. Recoveries of spiked samples range from 90.5 to 98.6 %, and the lower detection limits range from 9.7 to 12.0 μg kg. The method is selective and convenient. The m-MIPs were successfully applied to enrich and determine the carbamates in spiked homogenates of apples, oranges and pears. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

We show that Mn(II)-doped ZnS quantum dots coated with an acrylamide-based molecularly imprinted polymer (MIP-coated QDs) can act as a fluorescent probe for the selective and sensitive detection of the insecticide chlorpyrifos (CPF). The fluorescence of the coated QDs is quenched on loading the MIP with CPF, and the effect is much stronger for the MIP than for the non-imprinted polymer. The MIP-coated QDs were characterized by fluorescence spectrophotometry, X-ray powder diffraction, and scanning electron microscopy. Under optimal conditions, the relative fluorescence intensity of the MIP-coated QDs decreases linearly with the increasing concentration of CPF in the 0.3-60 μmol L concentration range, and the detection limit is 17 nmol L. The method has been used for the determination of CPF in spiked water samples and gave recoveries in the range from 87.1 to 94.5 % with relative standard deviations in the 2.9 to 6.5 % range. The method is simple, safe and inexpensive. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A novel method for the extraction of Sudan dyes including Sudan I, II, III, and IV from environmental water by magnetic titanium dioxide nanoparticles (FeO@TiO) coated with sodium dodecylsulfate (SDS) as adsorbent was reported. FeO@TiO was synthesized by a simple method and was characterized by transmission electron microscopy, Fourier-transform infrared spectrometry, and vibrating sample magnetometer. The magnetic separation was quite efficient for the adsorption and desorption of Sudan dyes. The effect of the amount of SDS, extraction time, pH, desorption condition, maximal extraction volume, and humic acid on the extraction process were investigated. This method was employed to analyze three environmental water samples. The results demonstrated that our proposed method had wide linear range (25-5,000 ng L) with a good linearity ( R > 0.999) and low detection limits (2.9-7.3 ng L). An enrichment factor of 1,000 was achieved. In all three spiked levels (25, 250, and 2,500 ng L), the recoveries of Sudan dyes were in the range of 86.9-93.6 %. The relative standard deviations obtained were ranging from 2.5 to 9.3 %. That is to say, the new method was fast and effective for the extraction of Sudan dye from environmental water. [ABSTRACT FROM AUTHOR]

The magnetic molecularly imprinted polymers (MMIPs) were prepared and used for the selective separation of chlorpyrifos from rice samples. The MMIPs were synthesized by surface-imprinted polymerization, using functionalized FeO particles as magnetic cores, chlorpyrifos as template, methacrylic acid as functional monomer, and trimethylolpropane trimethacrylate as cross-linker. Magnetic particles were characterized by scanning electron microscopy, Fourier-transform infrared spectrometry, physical property measurement system, and thermogravimetric analyzer. Adsorption studies were carried out to investigate the specific binding capacity, kinetics, and recognition specificity. The kinetic property of MMIPs was well fitted to the pseudo-second-order equation. The selective recognition experiment demonstrated that MMIPs had high selectivity towards chlorpyrifos over reference compound. Chlorpyrifos extracted from the rice samples was purified with MMIPs and detected by high-performance liquid chromatography. Under the optimal conditions, the detection limit of chlorpyrifos was 0.0072 μg g. The relative standard deviations of intra- and interday ranging from 2.4 to 4.6 % and from 3.5 % to 7.3 % were obtained, respectively. The recoveries of chlorpyrifos at three different fortified concentrations (0.025, 2.5, and 5 μg g) were in the range of 81.2-92.1 %. [ABSTRACT FROM AUTHOR]

We report on a method for the extraction of organophosphorus pesticides (OPPs) from water samples using mixed hemimicelles and magnetic titanium dioxide nanoparticles (FeO@TiO) modified by cetyltrimethylammonium. FeO@TiO nanoparticles were synthesized by a hydrothermal process and then characterized by scanning electron microscopy and Fourier transform IR spectrometry. The effects of the quantity of surfactant, extraction time, desorption solvent, pH value, extraction volume and reuse of the sorbent were optimized with respect to the extraction of OPPs including chlorpyrifos, dimethoate, and trichlorfon. The extraction method was applied to analyze OPPs in environmental water using HPLC along with UV detection. The method has a wide linear range (100-15,000 ng L), good linearity ( r > 0.999), and low detection limits (26-30 ng L). The enrichment factor is ~1,000. The recoveries (at spiked levels of 100, 1,000 and 10,000 ng L) are in the range of 88.5-96.7 %, and the relative standard deviations range from 2.4 % to 8.7 %. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Magnetic carbon nanotubes (MCNTs) have been synthesized by chemical deposition of FeO nanoparticles onto carbon nanotubes. They were characterized by Fourier transform infrared spectroscopy, scanning electron microscope, X-ray diffraction and physical property measurement system. The MCNTs were used as the sorbents for the extraction of pyrethroids including beta-cyfluthrin, cyhalothrin and cyphenothrin from tea samples. The extraction conditions, such as the amount of magnetic sorbent, shaking time and rate, washing and eluting solution have been fully investigated. The analytes desorbed from MCNTs were determined by HPLC with UV detection. Under the optimal conditions, the linearity of the method is in the range of 0.05-25 μg g. The limits of detection of the three pyrethroids are 0.017, 0.010 and 0.018 μg g, respectively. The relative standard deviations of within- and between-day range from 3.5 % to 6.4 %, and from 4.5 % to 29 7.3 %, respectively. In all three spiked levels (0.05, 0.5 and 5 μg g), the recoveries of pyrethroids are in the range of 82.2 %-94.4 %. This method is much faster and more effective than traditional methods, and it is promising for the analysis of pesticides residues. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A simple and fast method based on magnetic separation for extraction of pyrethroid pesticides including beta-cyfluthrin, cyhalothrin and cyphenothrin from environmental water samples has been established. Magnetic titanium dioxide was used as sorbent, which was synthesized by coating TiO on FeO in liquid-state co-precipitation method. The sorbent has been characterized by scanning electron microscopy and Fourier-transform infrared spectrometry, and the magnetic properties were investigated with physical property measurement system. Various parameters affecting the extraction efficiency were evaluated to achieve optimal condition and decrease ambiguous interactions. The analytes desorbed from the sorbent were detected by high performance liquid chromatography. Under the optimal condition, the linearity of the method is in the range of 25-2,500 ng L. The detection limits and quantification limits of pyrethroid pesticides are in the range of 2.8-6.1 ng L and 9.3-20.3 ng L, respectively. The relative standard deviations of intra- and inter-day tests ranging from 2.5 to 7.2 % and from 3.6 to 9.1 % were obtained. In all three spiked levels (25, 250 and 2,500 ng L), the recoveries of pyrethroid pesticides were in the range of 84.5-94.1 %. The proposed method was successfully applied to determine pyrethroids in three water samples. Cyphenothrin was found in one river water near farmlands, and its concentration was 52 ng L. [ABSTRACT FROM AUTHOR]

Arabidopsis thaliana WRKY39, a transcription factor that is induced by heat stress, is a member of the group II WRKY proteins and responds to both abiotic and biotic stress. Heat-treated seeds and plants of WRKY39 knock-down mutants had increased susceptibility to heat stress, showing reduced germination, decreased survival, and elevated electrolyte leakage compared with wild-type plants. In contrast, WRKY39 over-expressing plants exhibited enhanced thermotolerance compared with wild-type plants. RT-PCR and qRT-PCR analysis of wrky39 mutants and WRKY39 over-expressing plants identified putative genes regulated by WRKY39. Consistent with a role for WRKY39 in heat tolerance, the expression levels of salicylic acid (SA)-regulated PR1 and SA-related MBF1c genes were downregulated in wrky39 mutants. In contrast, over-expression of WRKY39 increased the expression of PR1 and MBF1c. The WRKY39 transcript was induced in response to treatment with SA or methyljasmonate. Analysis of heat stress-induced WRKY39 in defense signaling mutants, including coi1, ein2, and sid2, further indicated that WRKY39 was positively co-regulated by the SA and jasmonate (JA) signaling pathways. Together, these findings reveal that heat stress-induced WRKY39 positively regulates the cooperation between the SA- and JA-activated signaling pathways that mediate responses to heat stress. [ABSTRACT FROM AUTHOR]

A new dual-emission ratiometric fluorescent probe was synthesized and successfully used for the determination of Malachite Green (MG) in fish farming water. The ratiometric fluorescent probe was successfully composited by sol-gel method using C3N4 and CdTe quantum dots as fluorescent materials combined with mesoporous molecularly imprinted polymers. MG quenches the red fluorescence of the CdTe QDs (with excitation/emission wavelengths at 350/680 nm) while the blue fluorescence of C3N4 (with excitation/emission wavelengths at 350/458 nm) remains unchanged. The change of fluorescence color and fluorescence intensity ratio can be successfully used for quantification of malachite green. In addition, the mesoporous structure has a large surface and good adsorption capacity for malachite green. The normalized intensity of fluorescence increases linearly in the 50–1000 ng·mL−1 MG concentration range, and the detection limit is 10 ng·mL−1. The imprinting factor is 3.2. The nanoprobe was applied to the determination of MG in fish farming water samples. Recoveries and relative standard deviations were 92.5–97.8% and 2.5–6.2%, respectively. [ABSTRACT FROM AUTHOR]

The authors describe a fluorescent probe for sensitive and selective determination of quercetin, an indicator for the freshness of drinks. The probe consists of silica ball encapsulated graphitic carbon nitride (g-C3N4) modified with a molecularly imprinted polymer (MIP). It was synthesized via reverse microemulsion. The resulting MIP@g-C3N4 nanocomposite was characterized by fluorescence spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray powder diffraction. Quercetin quenches the fluorescence of the MIP@g-C3N4 probe. The effect was used to quantify quercetin in grape juice, tea juice, black tea, and red wine by fluorometry (λexc = 350 nm, λem = 460 nm). Response is linear in the 10-1000 ng mL−1 quercetin concentration range. The detection limit is 2.5 ng mL−1, recoveries range between 90.7 and 94.1%, and relative standard deviations are between 2.1 and 5.5%.Schematic of the synthesis of the MIP@g-C3N4 by a reverse microemulsion method. The probe was applied for the selective recognition and fluorometric determination of quercetin. [ABSTRACT FROM AUTHOR]

Subarachnoid haemorrhage (SAH) is a fatal neurovascular disease following cerebral aneurysm rupture with high morbidity and mortality rates. Long non-coding RNAs (lncRNAs) are a type of mammalian genome transcript, are abundantly expressed in the brain and are involved in many nervous system diseases. However, little is currently known regarding the influence of lncRNAs in early brain injury (EBI) after SAH. This study analysed the expression profiles of lncRNAs and mRNAs in SAH brain tissues of mice using high-throughput sequencing. The results showed a remarkable difference in lncRNA and mRNA transcripts between SAH and control brains. Approximately 617 lncRNA transcripts and 441 mRNA transcripts were aberrantly expressed at 24 hours after SAH. Gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that the differentially expressed mRNAs were mostly involved in inflammation. Based on the lncRNA/mRNA co-expression network, knockdown of fantom3_F730004F19 reduced the mRNA and protein levels of CD14 and toll-like receptor 4 (TLR4) and attenuated inflammation in BV-2 microglia cells. These results indicate that lncRNA fantom3_F730004F19 may be associated with microglia induced inflammation via the TLR signaling pathway in EBI following SAH. LncRNA represent a potential therapeutic target for the prognosis, diagnosis, and treatment of SAH. [ABSTRACT FROM AUTHOR]