A pH-regulated fluorescence covalent organic framework for quantitative water content detection in methanol

In this paper, we designed and synthesized a two-dimensional fluorescent covalent organic framework (TAPB-DMTP-COF) for the precise determination of H2O content in methanol. The COF was synthesized using two typical monomers by grinding method, which significantly reduced the synthesis time. By adjusting the pH value of the COF suspension to 4.0, the portion of the COF material structure is disrupted, thereby mitigating π-π stacking and resolving the aggregation-caused quenching (ACQ) effect. Consequently, the non-fluorescent TAPB-DMTP-COF exhibited blue-purple fluorescence emission in methanol. At the same time, it is observed that in the presence of H2O, there is a red shift in the maximum fluorescence emission peak of TAPB-DMTP-COF, which correlates with the H2O content within a specific range. Notably, this redshift demonstrates a linear relationship with H2O content from 4% to 80% in methanol. Our work presents novel insights for efficient analysis and detection of H2O content in methanol and could be used for H2O detection in other organic solvents.

Selective detection of ascorbic acid by tuning the composition and fluorescence of the cesium lead halide perovskite nanocrystals

Lead halide perovskite nanocrystals (PNCs) have attracted intense attention due to their excellent optoelectronic properties. In this work, a series of water-stable CsPb(Br/I)3PNCs fluorescent probes were prepared using an anion exchange method. It was found that the PNCs probes could be used to detect ascorbic acid (AA) in water, and interestingly, the FL spectra of the PNCs probes can be adjusted by controlling the concentration of KI in anion exchange to improve the detection selectivity of AA. The high sensitivity and selectivity make CsPb(Br/I)3PNCs an ideal material for AA sensing. The concentration of AA can be linearly measured in the range from 0.01 to 50μM, with a detection limit of 4.2 nM. The reason for the enhanced FL of CsPb(Br/I)3PNCs was studied, and it is considered that AA causes the aggregation of CsPb(Br/I)3PNCs. This strategy of improving the selectivity of the probe to the substrate by adjusting the spectrum will significantly expand the application of PNCs in the field of analysis and detection.

Chiral Assembly of Perovskite Nanocrystals: Sensitive Discrimination of Amino Acid Enantiomers

Chirality is a widespread phenomenon in nature and in living organisms and plays an important role in living systems. The sensitive discrimination of chiral molecular enantiomers remains a challenge in the fields of chemistry and biology. Establishing a simple, fast, and efficient strategy to discriminate the spatial configuration of chiral molecular enantiomers is of great significance. Chiral perovskite nanocrystals (PNCs) have attracted much attention because of their excellent optical activity. However, it is a challenge to prepare perovskites with both chiral and fluorescence properties for chiral sensing. In this work, we synthesized two chiral fluorescent perovskite nanocrystal assembly (PNA) enantiomers by using l- or d-phenylalanine (Phe) as chiral ligands. PNA exhibited good fluorescence recognition for l- and d-proline (Pro). Homochiral interaction led to fluorescence enhancement, while heterochiral interaction led to fluorescence quenching, and there is a good linear relationship between the fluorescence changing rate and l- or d-Pro concentration. Mechanism studies show that homochiral interaction-induced fluorescence enhancement is attributed to the disassembly of chiral PNA, while no disassembly of chiral PNA was found in heterochiral interaction-induced fluorescence quenching, which is attributed to the substitution of Phe on the surface of chiral PNA by heterochiral Pro. This work suggests that chiral perovskite can be used for chiral fluorescence sensing; it will inspire the development of chiral nanomaterials and chiral optical sensors.

An all-inorganic lead-free metal halide double perovskite for the highly selective detection of norfloxacin in aqueous solution

Lead-based perovskites are highly susceptible to environmental influences, and their application in analytical chemistry, especially in aqueous solution, has been reported rarely. All-inorganic lead-free metal halide perovskites have been considered as a substitute for lead-based perovskites. Herein, a Cs2RbTbCl6 perovskite microcrystal (PMCs), which emits strong yellow-green fluorescence with a maximum emission wavelength at 547 nm, was for the first time  synthesized and characterized. The Cs2RbTbCl6 PMCs could be well dispersed in N,N-dimethylacetamide (DMF), and its fluorescence could be significantly enhanced by the addition of norfloxacin (NOR) in the aqueous solution. We found that the Cs2RbTbCl6 PMCs can be used as fluorescent probes (excitation, 365 nm; emission, 547 nm) to selectively detect NOR in a concentration range from 10.0 to 200.0 μM with the limit of detection (LOD) being 0.04 μM. The Cs2RbTbCl6 PMCs could also be adsorbed on filter paper to fabricate as a fluorescent test paper for visual detection of NOR under 365-nm ultraviolet (UV) lamp irradiation. The proposed method has the potential to establish a new analytical method to visualize the detection of NOR in aqueous environments and also promotes the application of all-inorganic lead-free perovskites for analytical detection in aqueous environments.

Synthesis of a water-stable fluorescence CsPbBr3 perovskite by dual-supersaturated recrystallization method and tuning the fluorescence spectrum for selective detection of folic acid

As an excellent fluorescent material, cesium lead halide perovskite nanocrystals (PNCs) is rarely used for analytical purposes because the PNCs are unstable in polar solvents, especially water. Developing a new synthesis method to prepare water-stable PNCs makes it promising for the detection of analytes in aqueous solutions. Herein, by using the solubility difference of the precursors in different solvents, we successfully synthesized water-stable CsPbBr3 PNCs by a dual-supersaturated recrystallization method at room temperature. We also found that the fluorescence of the as-prepared CsPbBr3 PNCs could be quenched by some small organic molecules, such as folic acid (FA) and dopamine (DA). By using a chloride-induced anion exchange reaction method, the fluorescence emission peak of the CsPbBr3 PNCs could be tuned from 518 to 418 nm and the emission color changed from green to blue. The blue emission chloride-exchanged PNCs have a good selectivity for only FA and a good linear relationship is established between the fluorescence quenching rate of the PNCs and concentration of FA from 10.0 to 140.0 μM, with a limit of detection (LOD) of 0.9 μM. This work expanded the applications of PNCs in the field of analytical chemistry and also proposed a new strategy for improving selectivity by tuning the emission spectrum of a fluorescent probe.

Morphology regulation of isomeric covalent organic frameworks for high selective light scattering detection of lead

Isomerism is an essential and ubiquitous phenomenon in organic chemistry, yet it is rarely observed in covalent organic frameworks (COFs). Herein, we synthesized two framework-isomeric COFs (BATD-Dma-COF-K and BATD-Dma-COF-R) and found for the first time that the light scattering signal of the COFs can be used for the analytical detection of lead ion. By using solvothermal and room temperature solvent synthesis methods, controlling different synthesis conditions, and introducing regulators to increase the energy difference between different products, the product with the lowest energy could be synthesized under specific conditions. This method could control the morphology of the synthesized COF and realize the precise synthesis of framework-isomeric COF by changing the experimental conditions. The structures of the two framework-isomeric COFs were characterized and confirmed by a series of analytical methods. Based on the principle that lead ions coordinate with N and O on the surface of two skeletal isomers BATD-Dma-COFs to enhance the light scattering signal of the COFs, a light scattering probe was developed by BATD-Dma-COF for the detection of metal lead ion in water samples. Lead ion concentration in the range from 2.0 to 250.0 μM had a good linear relationship with the light scattering intensity increase of the COFs with detection limit as low as 0.8397 μM by BATD-Dma-COF-K and 0.9207 μM by BATD-Dma-COF-R.

Synthesis of a water-stable CsPbBr3 perovskite for selective detection of mercury ion in water

By using the method of low-temperature crystallization, CsPbBr3 perovskite nanocrystals (PNCs) coated with trifluoroacetyl lysine (Tfa-Lys) and oleamine (Olam) were synthesized in aqueous solution. The structure of the CsPbBr3 PNCs was characterized by many methods, such as ultraviolet (UV)-visible absorption spectrophotometer, fluorescence spectrophotometer, transmission electron microscopy (TEM), and X-ray diffraction (XRD) pattern. The fluorescence emission of the CsPbBr3 PNCs is stable in water for about 1 day at room temperature. It was also found that the fluorescence of the PNCs could be obviously and selectively quenched after the addition of mercury ion (Hg2+ ), allowing a visual detection of Hg2+ by the naked eye under UV light illumination. The fluorescence quenching rate (I0 /I) has a good linear relationship with the addition of Hg2+ in the concentration range 0.075 to 1.5 mg/L, with a correlation coefficient (R2 ) of 0.997, and limit of detection of 0.046 mg/L. The fluorescence quenching mechanism of the PNCs was determined by the fluorescence lifetime and X-ray photoelectron spectroscopy (XPS) of the PNCs. Overall, the synthesis method for CsPbBr3 PNCs is simple and rapid, and the as-prepared PNCs are stable in water that could be conveniently used for selective detection of Hg2+ in the water environment.

Transformable nano-antibiotics for mechanotherapy and immune activation against drug-resistant Gram-negative bacteria

The dearth of antibiotic candidates against Gram-negative bacteria and the rise of antibiotic resistance create a global health concern. The challenge lies in the unique Gram-negative bacterial outer membrane that provides the impermeable barrier for antibiotics and sequesters antigen presentation. We designed a transformable nano-antibiotics (TNA) that can transform from nontoxic nanoparticles to bactericidal nanofibrils with reasonable rigidity (Young's modulus, 21.6 ± 5.9 MPa) after targeting β-barrel assembly machine A (BamA) and lipid polysaccharides (LPSs) of Gram-negative bacteria. After morphological transformation, the TNA can penetrate and damage the bacterial envelope, disrupt electron transport and multiple conserved biosynthetic and metabolic pathways, burst bacterial antigen release from the outer membrane, and subsequently activate the innate and adaptive immunity. TNA kills Gram-negative bacteria in vitro and in vivo with undetectable resistance through multiple bactericidal modes of action. TNA treatment-induced vaccination results in rapid and long-lasting immune responses, protecting against lethal reinfections.

Enzyme-Activatable Polypeptide for Plasma Membrane Disruption and Antitumor Immunity Elicitation

Enzyme-instructed self-assembly of bioactive molecules into nanobundles inside cells is conceived to potentially disrupt plasma membrane and subcellular structure. Herein, an alkaline phosphatase (ALP)-activatable hybrid of ICG-CF₄ KY^p is facilely synthesized by conjugating photosensitizer indocyanine green (ICG) with CF₄ KY^p peptide via classical Michael addition reaction. ALP-induced dephosphorylation of ICG-CF₄ KY^p enables its transformation from small-molecule precursor into rigid nanofibrils, and such fibrillation in situ causes severe mechanical disruption of cytomembrane. Besides, ICG-mediated photosensitization causes additional oxidative damage of plasma membrane by lipid peroxidation. Hollow MnO₂ nanospheres devote to deliver ICG-CF₄ KY^p into tumorous tissue through tumor-specific acidity/glutathione-triggered degradation of MnO₂ , which is monitored by fluorescent probing and magnetic resonance imaging. The burst release of damage-associated molecular patterns and other tumor antigens during therapy effectively triggers immunogenetic cell death and improves immune stimulatory, as demonstrated by the promotion of dendritic cell maturation and CD8⁺ lymphocyte infiltration, as well as constraint of regulatory T cell population. Taken together, such cytomembrane injury strategy based on peptide fibrillation in situ holds high clinical promise for lesion-specific elimination of primary, abscopal, and metastatic tumors, which may enlighten more bioinspired nanoplatforms for anticancer theranostics.

[Constructing the Bayesian network models to explore the factors related to glomerular and tubular injury]

Objective: To construct Bayesian network (BN) models to explore the factors related to glomerular injury (GI) and tubular injury (TI). Methods: A cross-sectional study was carried out. From April to November 2019, Shanxi Provincial People's Hospital performed an opportunistic screening for chronic kidney disease in 10 counties of Shanxi Province. The general data and laboratory results of blood and urine samples were collected. Chi-square test and logistic regression were used to explore the related factors of GI and TI, which were included in the construction of BN models with max-min hill-climbing (MMHC) algorithm. Results: A total of 12 269 participants were included, there were 5 198 males and 7 071 females, with a median age of 58 (40-91) years. The prevalence of GI and TI was 12.7% (1 561/12 269) and 11.6% (1 425/12 269), respectively. The BN model consisted of 8 nodes and 10 edges for GI, and 11 nodes and 17 edges for TI, respectively. BN models showed that age and glycated hemoglobin were direct related factors for GI, while gender and fasting blood glucose were indirect related factors for GI. Age, gender, fasting blood glucose and glycosylated hemoglobin were direct related factors for TI. Additionally, the area under the receiver operating characteristic curve (AUC) was 0.761 (95%CI: 0.746-0.777) and 0.753 (95%CI: 0.736-0.769) for GI and TI BN models, respectively. Conclusions: BN models allow for identifying the complex network relationships among the factors related to GI and TI. Meanwhile, Bayesian risk reasoning can provide reference value for the clinical prevention of GI and TI.

[Establishment of a prognostic model for non-nephrotic membranous nephropathy based on unbalanced data]

Objective: To explore the construction of a machine learning model based on unbalanced data to predict the progression of non-nephrotic membranous nephropathy. Methods: The clinical and pathological data of patients diagnosed with non-nephrotic membranous nephropathy by renal biopsy in Shanxi People's Hospital from January 2018 to December 2021 were retrospectively analyzed.The prediction models were constructed based on logistic regression, support vector machine (SVM) and light gradient boosting machine (lightGBM), respectively. The mixed sampling technology was used to process the unbalanced data, and the area under the receiver operating characteristic curve (AUC) was used to evaluate the predictive performance of the models. Finally, Shapley additive explanation (SHAP) was used to interpret the results of the optimal prediction model. Results: A total of 148 patients were included in the study, including 84 males and 64 females, with a mean age of (47.2±12.5) years. The follow-up time [M(Q₁, Q₃)] was 14(7, 20) months. Twenty-three patients (15.5%) achieved the renal end-point event in the study. The SVM model had the highest AUC (0.868, 95%CI: 0.813-0.925), followed by logistic regression (AUC=0.865, 95%CI: 0.755-0.899) and lightGBM (AUC=0.791, 95%CI: 0.690-0.882). The feature recursive elimination cross validation (RFECV) method based on random forest (RF) and the SHAP plot based on the SVM model showed that immunohistochemistry IgG, total protein (TP), anti-phospholipase A2 receptor (anti-PLA2R), blood chloride and D-Dimer were risk factors affecting the progress of non-nephrotic membranous nephropathy. Moreover, patients with high immunohistochemistry IgG, anti-PLA2R and D-Dimer had an increased risk of achieving the renal end-point event. Conclusion: The SVM model established in this study can effectively predict the progress of non-nephrotic membranous nephropathy, and provide a new method for the early identification of high-risk patients and precision therapy.

[Whole-course management strategies for gastroesophageal reflux disease: an evidence mapping study based on clinical practice guidelines]

Gastroesophageal reflux disease (GERD) is one of the most common digestive diseases with high incidence, complicated clinical symptoms, difficulties in standard treatment, and heavy medical burden. At present, some GERD-relevant clinical practice guidelines (CPGs) have been issued by different countries and academic organizations, but some recommendations were inconsistent, which has caused some problems for the current clinical whole-course management of GERD. To summarize the relevant evidence among the CPGs on GERD and formulate the whole- course management strategies, we included GERD-relevant CPGs published or updated after 2010 by searching websites of guidelines, relevant professional societies, and electronic databases. We extracted the recommendations and summarized the evidence from the aspects of symptoms, epidemiology, diagnosis and treatment, which was presented in the form of evidence mapping. We included 24 CPGs, including three in Chinese and 21 in English. The clinical practice management strategies of GERD were formulated based on the evidence from the aspects of clinical symptoms, diagnostic methods, medical treatment, anti-reflux surgery and endoscopic treatment, psychological treatment, and traditional Chinese medicine treatment.

[Efficacy and safety of various doses of hybutimibe monotherapy or in combination with atorvastatin for primary hypercholesterolemia: a multicenter, randomized, double-blind, double-dummy, parallel-controlled phase Ⅲ clinical trial]

Objective: To evaluate the efficacy and safety of hybutimibe monotherapy or in combination with atorvastatin in the treatment of primary hypercholesterolemia. Methods: This was a multicenter, randomized, double-blind, double-dummy, parallel-controlled phase Ⅲ clinical trial of patients with untreated primary hypercholesterolemia from 41 centers in China between August 2015 and April 2019. Patients were randomly assigned, at a ratio of 1∶1∶1∶1∶1∶1, to the atorvastatin 10 mg group (group A), hybutimibe 20 mg group (group B), hybutimibe 20 mg plus atorvastatin 10 mg group (group C), hybutimibe 10 mg group (group D), hybutimibe 10 mg plus atorvastatin 10 mg group (group E), and placebo group (group F). After a dietary run-in period for at least 4 weeks, all patients were administered orally once a day according to their groups. The treatment period was 12 weeks after the first dose of the study drug, and efficacy and safety were evaluated at weeks 2, 4, 8, and 12. After the treatment period, patients voluntarily entered the long-term safety evaluation period and continued the assigned treatment (those in group F were randomly assigned to group B or D), with 40 weeks' observation. The primary endpoint was the percent change in low density lipoprotein cholesterol (LDL-C) from baseline at week 12. Secondary endpoints included the percent changes in high density lipoprotein cholesterol (HDL-C), triglyceride (TG), apolipoprotein B (Apo B) at week 12 and changes of the four above-mentioned lipid indicators at weeks 18, 24, 38, and 52. Safety was evaluated during the whole treatment period. Results: Totally, 727 patients were included in the treatment period with a mean age of (55.0±9.3) years old, including 253 males. No statistical differences were observed among the groups in demographics, comorbidities, and baseline blood lipid levels. At week 12, the percent changes in LDL-C were significantly different among groups A to F (all P<0.01). Compared to atorvastatin alone, hybutimibe combined with atorvastatin could further improve LDL-C, TG, and Apo B (all P<0.05). Furthermore, there was no significant difference in percent changes in LDL-C at week 12 between group C and group E (P=0.991 7). During the long-term evaluation period, there were intergroup statistical differences in changes of LDL-C, TG and Apo B at 18, 24, 38, and 52 weeks from baseline among the statins group (group A), hybutimibe group (groups B, D, and F), and combination group (groups C and E) (all P<0.01), with the best effect observed in the combination group. The incidence of adverse events was 64.2% in the statins group, 61.7% in the hybutimibe group, and 71.0% in the combination group during the long-term evaluation period. No treatment-related serious adverse events or adverse events leading to death occurred during the 52-week study period. Conclusions: Hybutimibe combined with atorvastatin showed confirmatory efficacy in patients with untreated primary hypercholesterolemia, which could further enhance the efficacy on the basis of atorvastatin monotherapy, with a good overall safety profile.

Transformable Helical Self-Assembly for Cancerous Golgi Apparatus Disruption

Golgi apparatus is a major subcellular organelle responsible for drug resistance. Golgi apparatus-targeted nanomechanical disruption provides an attractive approach for killing cancer cells by multimodal mechanism and avoiding drug resistance. Inspired by the poisonous twisted fibrils in Alzheimer's brain tissue and enhanced rigidity of helical structure in nature, we designed transformable peptide C₆RVRRF₄KY that can self-assemble into nontoxic nanoparticles in aqueous medium but transformed into left-handed helical fibrils (L-HFs) after targeting and furin cleavage in the Golgi apparatus of cancer cells. The L-HFs can mechanically disrupt the Golgi apparatus membrane, resulting in inhibition of cytokine secretion, collapse of the cellular structure, and eventually death of cancer cells. Repeated stimulation of the cancers by the precursors causes no acquired drug resistance, showing that mechanical disruption of subcellular organelle is an excellent strategy for cancer therapy without drug resistance. This nanomechanical disruption concept should also be applicable to multidrug-resistant bacteria and viruses.

Multifunctional SGQDs-CORM@HA nanosheets for bacterial eradication through cascade-activated "nanoknife" effect and photodynamic/CO gas therapy

Infection associated with multidrug-resistant (MDR) bacteria has become a serious threat to public health, and there is an urgent demand of developing new antibiotics that offer combinatorial therapy to effectively combat MDR. Herein, a multifunctional two-dimensional nanoantibiotic was facilely designed and established on the basis of the covalent conjugation of CO-releasing molecule (CORM-401) and electrostatic adsorption of hyaluronic acid (HA) onto single-layered graphene quantum dots (SGQDs) to assemble SGQDs-CORM@HA nanosheets, abbreviated as SCH. Upon the enrichment of as-prepared nanoantibiotics in the community of targeted microbe, bacterial-secreted hyaluronidase (HAase) would cleave HA on SCH, and the sharp edges as well as the reactive sites on SGQDs-CORM nanosheets were exposed for cascade activation of synergistic antibacterial effects. Specifically, ultrathin SGQDs-CORM nanosheets can penetrate into bacterial cells deemed as the unique "nanoknife" effect. Under white light irradiation, SGQDs-CORM nanosheets can act as a high-efficient photosensitizer to generate cytotoxic singlet oxygen (¹O₂), as a well-recognized reactive oxygen species (ROS), to produce high oxidative stress and damage bacteria. As a complementary to photodynamic therapy (PDT), the accumulation of local ROS further triggered the release of CO to hinder the bacterial growth via causing plasma membrane damage and inducing metabolic disorders. Such synergistic treatment regimen arising from cascade-activated "nanoknife" effect and photodynamic/CO gas therapy, was devoted to outstanding on-demand antibacterial performance both in vitro and in vivo. Fascinatingly, the nanoplatform showed good biocompatibility toward both normal somatic cells and non-targeted bacteria. The remarkable antibacterial capability and admirable biocompatibility endow SCH with great potential to fight against MDR pathogens for in-coming clinical translations.

Aggregation-Enhanced Energy Transfer for Mitochondria-Targeted ATP Ratiometric Imaging in Living Cells

Förster resonance energy transfer (FRET) from fluorescent nanoparticles to fluorescent dyes is an attractive approach for bioanalysis in living cells. However, the luminescence of the nanoparticle donor/acceptor has not been effectively used to produce highly efficient FRET because the distance between the energy donor and energy acceptor is often larger than the effective FRET radius (about 10 nm) and the uncontrolled rotational and translational diffusion of luminophores. Here, we develop an aggregation-enhanced energy transfer strategy that can overcome the impedance for effective energy transfer. The functional nanoprobes, named TPP-CDs-FITC, are carbon dots (CDs) functionalized with triphenylphosphine (TPP) and ∼117 fluorescein 5-isothiocyanate (FITC) on the surface. In dispersed solution, the 3.8 nm TPP-CDs-FITC show weak FRET efficiency (15.4%). After TPP-instructed mitochondrial targeting, enhanced FRET efficiency (53.2%) is induced due to the aggregation of TPP-CDs-FITC selectively triggered by adenosine triphosphate (ATP) in the mitochondria. The enhanced FRET efficiency can be attributed to the joint effect of the augment of numbers of FITC acceptors within 10 nm from dispersed 117 to aggregated 5499 and the restricted rotational and translational motions of TPP-CDs donors and FITC acceptors. Ultimately, we successfully observe the fluctuations of ATP levels in the mitochondria using the aggregation-enhanced energy transfer strategy of the TPP-CDs-FITC nanodevice.

[Effect of miR-186 targeting E-cadherin on proliferation and metastasis of renal cell carcinoma]

Objective: To investigate the role of miR-186 in renal cell carcinoma (RCC) and its molecular mechanism of miR-186 targeting E-cadherin to inhibit cell proliferation and metastasis of RCC. Methods: A total of 40 RCC samples which were collected in Shanxi Provincial People's Hospital from January 2015 to January 2019 and four RCC cell lines were measured the expression of miR-186 by real-time quantitative polymerase chain reaction (qPCR). The effect of miR-186 overexpression on the proliferation, invasion, migration and apoptosis of 786-O cells were detected by cell counting kit-8(CCK-8), colony formation, wound healing and Transwell assay and flow cytometric analysis. The effect of miR-186 on the expression of epithelial-to-mesenchymal transition (EMT) related markers (E-cadherin, N-cadherin and Vimentin) was analyzed by Western blot, and the dual luciferase reporter was used to verify the miR-186 targeting E-cadherin. Results: There were 26 males and 14 females with an age of (58.4±9.2) years. miR-186 expression levels decreased significantly in RCC tissues and cells (tissues: 0.005 2±0.000 4 vs 0.015 5±0.001 5, P<0.001; cells: 0.334 3±0.025 1, 0.457 0±0.026 6, 0.229 8±0.011 0, 0.741 1±0.091 0 vs 1.000 0±0.085 2, all P<0.001). The expression of miR-186 had a negative correlation with tumor size (≥4 cm: 0.003 2±0.003 4 vs<4 cm: 0.008 4±0.007 2, P<0.001), TNM staging (≤Ⅱ: 0.007 8±0.005 8 vs>Ⅱ: 0.002 7±0.002 3, P=0.021) and Fuhrman grade (<Ⅱ: 0.008 8±0.006 3 vs ≥Ⅱ: 0.004 6±0.003 0, P<0.001). The overexpression of miR-186 significantly inhibited cell proliferation and metastasis, and induced cell apoptosis. delivered.miR-186 overexpression can retard tumor growth in nude mice. Luciferase assay showed that E-cadherin was a direct target gene of miR-186. Conclusion: miR-186 may affect EMT of RCC and inhibit the proliferation and metastasis of RCC by directly regulating E-cadherin.

Nonamplification Multiplexed Assay of Endonucleases and DNA Methyltransferases by Colocalized Particle Counting

Restriction endonucleases (ENases) and DNA methyltransferases (MTases) are important enzymes in biological processes, and detection of ENases/MTases activity is significant for biological and pharmaceutical studies. However, available nonamplification methods with a versatile design, desirable sensitivity, and signal production mode of unbiased quantification toward multiple nucleases are rare. By combining deliberately designed hairpin DNA probes with the colocalized particle counting technique, we present a nonamplification, separation-free method for multiplexed detection of ENases and MTases. In the presence of target ENases, the hairpin DNA is cleaved and the resulting DNA sequence forms a sandwich structure to tie two different-colored fluorescent microbeads together to generate a colocalization signal that can be easily detected using a standard fluorescence microscope. The multiplexed assay is realized via different color combinations. For the assay of methyltransferase, methylation by MTases prevents cleavage of the hairpin by the corresponding ENase, leading to decreased colocalization events. Three ENases can be simultaneously detected with high selectivity, minimal cross-talk, and detection limits of (4.1-6.4) × 10^-4 U/mL, and the corresponding MTase activity can be measured without a change of the probe design. The potential for practical application is evaluated with human serum samples and different ENase and MTase inhibitors with satisfactory results. The proposed method is separation-free, unbiased toward multiple targets, and easy to implement, and the strategy has the potential to be extended to other targets.

Polarity-Sensitive Polymer Carbon Dots Prepared at Room-Temperature for Monitoring the Cell Polarity Dynamics during Autophagy

Taking the advantages of excellent optical properties, biocompatibility, and photostability of carbon dots, herein, we developed polarity-sensitive polymer carbon dots (PCDs) for visualizing of cellular polarity to real-time monitoring autophagy changes without perturbing the cellular status. The PCDs can be prepared by simply mixing dopamine (DA), H₂O₂, and o-phenylenediamine (o-PDA) in a common beaker without the need for any special equipment or external energy supply, and the preparation could be completed within 3 min at room temperature. Interestingly, the polarity-sensitive PCDs could emit various types of fluorescence and are insensitive to the excitation light when dispersed in different water/dioxane systems with different polarities. Based on the polarity-sensitive emission of the PCDs, the change of polarity during autophagy has been successfully monitored in living cells. Moreover, the change of polarity detected by PCDs is autophagy-specific (does not occur during apoptosis), occurs under different autophagy-inducing situations (starvation, rapamycin, and trehalose), and requires a normal autophagic flux, showing that PCDs rapidly prepared by polymerization cross-linking at room temperature can be functionally applied in the case of autophagy-related physiological or pathological processes.

[Malfunction of autophagy in tibial growth plate chondrocytes causes increased apoptosis rate in chronic renal insufficiency rats]

Objective: To observe the effect of autophagy of tibial growth plate chondrocyte on apoptosis in chronic renal insufficiency (CRI) rats. Methods: Male 4-week-old SD rats were randomly divided into two groups: (1) Sham group: only the left ureter was exposed (n=10); (2) CRI group: the left ureter was ligated to cause CRI (n=10). The urine from all the rats was collected 6 weeks after the operation and the total protein content was measured. Then all the rats were sacrificed and the concentrations of creatinine and urea nitrogen in intracardiac blood were detected. The proximal tibia were fixed and decalcified to prepare histological sections, and the number of chondrocytes of column cells in the proliferative area of tibia growth plate was observed by saffron O staining. The expression rate of protein Light Chain-3, an autophagy marker of chondrocytes, was detected by immunofluorescence. The apoptosis rate of chondrocytes was detected by the method of TUNEL assay. The level of glycogenin-1, a glycogen formation marker of chondrocyte was detected by immunohistochemistry in chondrocytes. Results: The 24 h urine total protein was higher in CRI group [(163.5±11.3) mg vs (38.6±9.8) mg, t=25.620, P<0.001]. The levels of blood creatinine [(67.3±16.2) μmol/L vs (28.4±11.5) μmol/L, t=5.974, P<0.001] and urea nitrogen [(16.4±6.4) mmol/L vs (4.8±2.0) mmol/L, t=5.198, P<0.001] were higher in CRI group. The number of chondrocytes of column cells in the proliferating area of tibia growth plate was lower in CRI group (4.2±2.1 vs 9.1±3.8, t=3.109, P=0.006). The expression rate of LC-3 protein in chondrocytes of CRI group was lower [(27.2±12.6)% vs (51.4±18.2)%, t=3.457, P=0.003]. The level of glycogenin-1 of chondrocytes in CRI group increased significantly (6.1±2.5 vs 3.5±1.8, t=2.669, P=0.016). The apoptosis rate of chondrocytes in CRI group also increased [(17.2±4.8)% vs (5.1±3.4)%, t=6.505, P<0.001]. Conclusion: Malfunction of autophagy in tibial growth plate chondrocytes causes increased apoptosis rate in CRI rats, which might be caused by the failure of glycogen degradation in chondrocytes.

[Effect of primary cilia expression rate on Wnt/β signaling pathway in tibial growth plate chondrocytes from chronic renal insufficiency young rats]

Objective: To observe the effect of primary cilia expression rate on Wnt/β signaling pathway in tibial growth plate chondrocytes from chronic renal insufficiency (CRI) young rats. Methods: Male 2-week-old SD rats were randomly divided into two groups: (1) Sham group: only the left ureter was exposed (n=6); (2) CRI group: the left ureter was ligated (n=6). Rats were sacrificed 2 weeks after the operation and the primary cilia expression rate of growth plate chondrocytes and key protein β-catenin in Wnt/β signaling pathway were observed in histological section of tibia specimen. Chondrocytes isolated from growth plate in two groups were cultured in vitro to P3 generation. The primary cilia expression rate and the level of β-catenin were measured. The primary cilia expression rate was detected by agonists and antagonists Wnt/β signaling pathway in chondrocytes of CRI group. The level of β-catenin was detected by using serum-free culture and chloral hydrate to intervene chondrocytes in CRI group. Results: The primary cilia expression rate of growth plate chondrocytes in histological section of tibia specimen in CRI group was higher than that in Sham group [(17.5±7.7)% vs (8.7±3.6)%, t=3.237, P=0.005], and the level of β-catenin was higher in CRI group (5.1±0.7 vs 1.9±0.8, t=6.731, P<0.001). The primary cilia expression rate of growth plate chondrocytes cultured in vitro in CRI group was higher than that in Sham group [(20.9±8.1)% vs (11.8±4.7)%, t=3.073, P=0.007], and the level of β-catenin was higher in CRI group (0.49±0.12 vs 0.25±0.11, t=3.297, P=0.011). There was no significant change in primary cilia expression rate after intervention by using Wnt/β signaling agonists and antagonists to change the level of β-catenin [agonists group: (21.3±7.6)%, control: (20.6±6.8)%, antagonists group: (22.4±6.2)%, F=0.173, P=0.842]. The level of β-catenin was significantly changed after intervention by using serum-free culture, chloral hydrate to alter the primary cilia expression rate (serum-free culture group: 0.61±0.23, control: 0.39±0.24, chloral hydrate group: 0.15±0.11, F=6.476, P=0.012). There was a positive correlation between the level of β-catenin and primary cilia expression rate. Conclusion: The primary cilia expression rate and the level of Wnt/β signaling pathway were higher in tibial growth plate chondrocytes in CRI rats model, and primary cilia might have positive regulatory effects on the Wnt/β signaling pathway.

[Effect of primary cilia on growth plate chondrocyte proliferation of young rats with chronic renal insufficiency]

Objective: To observe the effect of primary cilia on growth plate chondrocyte proliferation of young rats with chronic renal insufficiency (CRI). Methods: Male 2-week-old Sprague-Dawley rats were randomly divided into two groups (with 10 in each group): Sham group (only left ureter was exposed) and CRI group (left ureter was ligated). Rats were sacrificed 2 weeks after operation and the total length of tibia was measured. Histological sections of tibia were taken to observe the chondrocytes of growth plate proliferative region and the expression rate of primary cilia. Chondrocytes from growth plate in two groups were isolated and cultured in vitro to P3 generation and the chondrocyte proliferation rate at 24 h were detected. The primary cilia expression rate and cilia length of chondrocytes were measured. Western blot was used to detect the expression of intraflagellar transport 88 (IFT88) protein and the gray scale was analyzed. Results: The total length of tibia was shorter in CRI group [(35.84±4.56) mm vs (42.33±3.44) mm, P=0.002]. The results of tibial histological section showed that chondrocytes of growth plate proliferative region were unorganized and the number of chondrocyte with columnar structure was less in CRI group (2.71±1.10 vs 7.68±1.32, P<0.001). The primary cilia expression rate of chondrocytes was higher in CRI group [(35.53±7.41)% vs (18.31±5.12)%, P<0.001]. The chondrocyte proliferation rate at 24 h was lower in CRI group [(11.38±6.10)% vs (24.35±8.46)%, P=0.001]. The primary cilia expression rate of chondrocytes was higher in CRI group [(60.12±7.86)% vs (32.17±8.97)%, P<0.001], and the primary cilia length of chondrocytes was longer in CRI group [(3.54±1.61) μm vs (1.96±0.82) μm, P=0.012]. The protein IFT88 was more highly expressed in CRI group (0.47±0.23 vs 0.17±0.10, P=0.001). Conclusion: The primary cilia expression rate of growth plate chondrocytes was higher in the rats with CRI, resulting in decreased chondrocyte proliferation rate and growth retardation of tibial growth plate.

Nitrogen and phosphorus doped polymer carbon dots as a sensitive cellular mapping probe of nitrite

Nitrite (NO₂ ^-) is one of the important pollutants in food and the environment, which can seriously endanger the health of human beings. Therefore, detecting nitrite in food, environmental and biological samples is very significant for health monitoring. Herein, polymer carbon dots (PCDs) doped with nitrogen and phosphorus were prepared by polymerization of ascorbic acid (AA) and polyethylenimine (PEI) with phosphoric acid, and exhibited excellent stability, adjustable fluorescence emissions and good biocompatibility. It was found that the PCDs presented a sensitive response to nitrite (NO₂ ^-), and they were successfully applied for NO₂ ^- analysis in water and milk samples, and the dynamic monitoring of nitrite entry into Hep-2 cells.

Time-resolved visual detection of heparin by accelerated etching of gold nanorods

Plasmonic gold nanorods are promising and sensitive light scattering probes, which can reach the single particle level. Herein, we present the light scattering properties of gold nanorods for time-resolved visual detection of heparin based on the rapid etching of gold nanorods under dark-field microscopy.

Precise ricin A-chain delivery by Golgi-targeting carbon dots

The as-prepared CDs–RTA conjugates exhibit enhanced internalization, improved stability against enzymatic digestion and an increased location rate of RTA to the ER, and thus much more RTA could translocate to the cytosol and ribosome to exert toxic effects.

[Mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot]

Objective: To explore mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot. Methods: Forty-eight Sprague Dawley rats were divided into control group (n=12) and injury group (n=36) according to the random number table. Rats in injury group were placed in smoke-induced injury experimental equipment fulled with white smoke from burning smoke pot for 5 minutes to make lung injury, and rats in control group were placed in smoke-induced injury experimental equipment fulled with air for 5 minutes to make sham injury. Six rats in injury group at post injury hour (PIH) 6, 24, and 72 and six rats in control group at PIH 72 were collected to observe pathological changes of lung tissue and pathological score of rats in the two groups by hematoxylin-eosin staining, to detect expression of nuclear factor-κB (NF-κB) p65 mRNA in lung tissue of rats by reverse transcriptional polymerase chain reaction, and to detect content of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 in lung tissue of rats by enzyme-linked immunosorbent assay. Data were processed with one-way analysis of variance and t test. Results: At PIH 72, lung tissue structure of rats in control group was clear and complete, with no inflammatory cell infiltration. At PIH 6, there was edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group. At PIH 24, edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group aggravated. At PIH 72, area of edema in lung tissue of rats in injury group was enlarged, with obvious hemorrhage and inflammatory cell infiltration. At PIH 6, 24, and 72, pathological score of lung tissue of rats in injury group was (3.43±0.86), (5.39±0.93), and (9.99±0.84) points, respectively, obviously higher than that of rats in control group at PIH 72 [(2.11±0.20) points, t=3.659, 8.450, 22.355, P<0.05]. As time post injury prolonged, pathological scores of lung tissue of rats in injury group were significantly increased (F=121.244, P<0.01). At PIH 6, 24, and 72, expression of NF-κB p65 mRNA in lung tissue of rats in injury group was 15.5±4.3, 25.9±1.8, 30.9±3.5 respectively, significantly higher than that of rats in control group at PIH 72 (7.8±0.8, t=4.315, 20.445, 14.408, P<0.01). As time post injury prolonged, expression of NF-κB p65 mRNA in lung tissue of rats in injury group gradually increased (F=32.691, P<0.01). At PIH 6, 24, and 72, content of TNF-α, IL-1β, and IL-6 in lung tissue of rats in injury group was significantly higher than that of rats in control group at PIH 72, respectively (t=7.650, 8.968, 6.827, 6.726, 8.978, 3.460, 5.420, 13.289, 16.438, P<0.01). At PIH 24, content of TNF-α and IL-1β in lung tissue of rats in injury group was higher than that of rats in the same group at PIH 6 and 72, respectively (t=3.409, -2.549, 4.047, -4.100, P<0.05). At PIH 24 and 72, content of IL-6 in lung tissue of rats in injury group was respectively higher than that of rats in the same group at PIH 6 (t=8.273, 9.711, P<0.05). Conclusions: After inhaling white smoke from burning smoke pot, rats are inflicted with lung injury by increasing expression of NF-κB p65 mRNA and content of TNF-α, IL-1β, and IL-6, and induce pathological changes of edema, hemorrhage, and inflammatory cell infiltration of lung tissue.

Mitochondria-targeting single-layered graphene quantum dots with dual recognition sites for ATP imaging in living cells

As a molecular unit of intracellular energy transfer, adenosine triphosphate (ATP) is significant for maintaining the energy balance in living cells and thus monitoring cellular ATP is important to assess cellular physiological functions. However, effective monitoring of cellular ATP still faces challenges owing to the similarity of ATP to other nucleoside polyphosphates. Herein, yellow emissive single-layered graphene quantum dots (s-GQDs) with dual recognition sites including π-conjugated single sheets and positively charged sites were developed. The s-GQDs exhibit a good mitochondria targeting ability and respond only to purine nucleotides and show good selectivity in discriminating tri-, di- and monophosphate nucleotides. The good selectivity should be attributed to the concurrent effect of π-π stacking and electrostatic interactions between filmy layered positive s-GQDs and negative purine nucleotides. Owing to the mitochondria targeting ability and dual recognition sites of the s-GQDs, the mitochondrial ATP fluctuation resulting from the activation and suppression of ATP in living cells has been successfully monitored.

A functional preservation strategy for the production of highly photoluminescent emerald carbon dots for lysosome targeting and lysosomal pH imaging

Lysosomes, which can be easily targeted by molecules with abundant amino groups, play critical roles in endocytosis, autophagy, and phagocytosis; thus, it is important to accurately characterize lysosomes, including lysosomal pH, in living cells to understand their physiological and pathological functions. Herein, a new type of highly photoluminescent (PL) emerald carbon dots (CDs) was easily prepared through a functional preservation strategy (FPS) by simply mixing p-benzoquinone and ethanediamine at room temperature. The as-prepared CDs possessed abundant amino groups preserved from ethanediamine owing to FPS, and they exhibited excellent photostability as compared to the commercial LysoTracker probes. Consequently, they actively targeted lysosomes to sensitively respond to lysosomal pH in vitro owing to their abundant amino groups and good hydrophilicity. Thus, we could successfully monitor lysosomal pH dynamics during apoptosis in live cells.

Redox-Active AIEgen-Derived Plasmonic and Fluorescent Core@Shell Nanoparticles for Multimodality Bioimaging

Multimodality imaging is highly desirable for accurate diagnosis by achieving high sensitivity, spatial-temporal resolution, and penetration depth with a single structural unit. However, it is still challenging to integrate fluorescent and plasmonic modalities into a single structure, as they are naturally incompatible because of significant fluorescence quenching by plasmonic noble-metal nanoparticles. Herein, we report a new type of silver@AIEgen (aggregation-induced emission luminogen) core-shell nanoparticle (AACSN) with both strong aggregated-state fluorescence of the AIEgen and distinctive plasmonic scattering of silver nanoparticles for multimodality imaging in living cells and small animals. The AACSNs were prepared through a redox reaction between silver ions and a redox-active AIEgen, which promoted synergistic formation of the silver core and self-assembly of the AIEgen around the core. The resulting AACSNs exhibited good biocompatibility and high resistance to environmental damage. As a result, excellent performance in fluorescence imaging, dark-field microscopy, and X-ray computed tomography-based multimodality imaging was achieved.

DNA hydroxymethylation rate in the AChE and HoxC4 promoter associated with human sperm quality

The relationship of altered DNA 5'-hydroxymethylation in human spermatozoa with seminal parameters remains unclear. The aim of the study was to investigate the association between the 5'-hydroxymethylcytosine (5hmC) rate in the promoters of acetylcholinesterase (AChE) and homeobox C4 (HoxC4) genes and human sperm concentration/motility. The study population consisted of three groups: asthenozoospermia (AZ), oligoasthenozoospermia (OAZ) and normozoospermia (NZ). The 5hmC rate in the promoter was measured by CCGG loci-dependent MspI/HpaII restriction mapping of glycosylation-modified sperm DNA combined with a hydroxymethylation-specific real-time polymerase chain reaction assay. The 5hmC rate in the AChE promoter in group AZ and OAZ was higher than that in group NZ (p < .05). A weak inverse correlation between 5hmC rate of AChE and sperm motility was observed in all subjects (r = -.172, p < .05). The 5hmC rate in the HoxC4 promoter in group OAZ was lower than that in group NZ (p < .05). These results indicated that altered 5hmC rates of AChE and HoxC4 promoters are associated with low sperm motility and sperm concentration respectively.

[The vessel and primary glaucoma]

Glaucoma, as the first leading cause of irreversible blindness in the world, is a chronic progressive optic neuropathy. The pathogenesis of glaucoma is still not fully understood till now. A lot of studies about vascular diameter, tortuosity, location, disc perfusion, vascular regulation and systemic vascular factors had been conducted to investigate the relationship between the vascular states and glaucoma since vascular hypothesis proposed. However, direct and convincing evidence for primary mechanisms of glaucoma is still lacking. The development of OCT, especially the Angio-OCT makes the real time visualization and measurement of ocular perfusion in vivo possible, gives some new evidences of vascular dysfunction of optic nerve head associated with glaucoma, which enhancing thinking of the pathogenesis of glaucoma. This review summarizes the literatures on vascular factors associated with glaucoma to provide the references for clinical researches. (Chin J Ophthalmol, 2017, 53:791-796).

The aggregation induced emission quenching of graphene quantum dots for visualizing the dynamic invasions of cobalt(ii) into living cells

A highly sensitive and selective approach for cobalt(ii) detection based on the aggregation induced emission quenching strategy, which is opposite to aggregation induced emission enhancement, was developed using graphene quantum dots (GQDs). The detection could be achieved in the range of 10 nM-5 μM and the limit of detection was 2 nM. Importantly, the as-prepared GQDs showed a specific response to cobalt(ii) with excellent stability in A549 cells owing to their good biocompatibility and long-time anti-photobleaching. Thus, these environmentally and bio-friendly carbon nanomaterials were employed to visualize and monitor significant physiological changes of living cells induced by cobalt(ii). This shows great potential for in vitro analysis of cobalt(ii).

Chiral nanoprobes for targeting and long-term imaging of the Golgi apparatus

The targeting and long-term imaging of the Golgi apparatus have been realized vial-cysteine functionalized nanoprobes.

The Golgi apparatus is an essential subcellular organelle. Targeting and monitoring the Golgi change at the single-cell level over a long time scale are critical but are challenges that have not yet been tackled. Inspired by the precise Golgi positioning ability of galactosyltransferase and protein kinase D, due to their cysteine residues, we developed a method for long-term Golgi imaging. Fluorescent molecules, carbon quantum dots (CQDs) and silica nanoparticles could target the Golgi when they are modified with l-cysteine. l-Cysteine-rich chiral carbon quantum dots (LC-CQDs), which have the benefits of a high Golgi specificity from l-cysteine and excellent photostability and biocompatibility from the CQDs, are proven to be highly suitable for long-term in situ imaging of the Golgi. Investigation of the mechanism showed that free thiol groups and the l-type stereo configuration of LC-CQDs are essential for specific targeting of the Golgi. With the aid of the as-prepared LC-CQDs, the dynamic changes of the Golgi in the early stage of viral infection were visualized. The Golgi targeting and imaging strategy used in this work is beneficial for Golgi-targeted drug delivery and early diagnosis and therapy of Golgi diseases.

Real-time dark-field light scattering imaging to monitor the coupling reaction with gold nanorods as an optical probe

Gold nanorods (GNRs) have opened up promising applications based on their reshaping, due to the fact that a tiny change in shape or size could directly lead to optical changes. Herein, we report chemical reshaping of GNRs induced by the coupling reaction between Au, ferric chloride and thiourea. In the coupling reaction, Fe³⁺ oxidizes the GNRs to yield Au(i), which complexes with the thiourea ligand, lowering the Gibbs free energy of the gold species and promoting the reaction equilibrium to enable the chemical reshaping of the GNRs. This coupling reaction process was monitored using a light-scattering dark-field microscopy (DFM) imaging technique and scanning electron microscopy (SEM). The light scattering underwent a colour change from bright red to yellow and finally to green, and the GNRs underwent a morphological change from rod-shaped to fusiform and finally to spherical, which is somewhat different from the results of other chemical etching processes of GNRs. It is believed that the coupling reaction induced chemical reshaping of GNRs not only provides an alternative way to monitor the coupling reaction, but also offers a facile way to obtain a desirable GNR morphology, which is important for the preparation of fusiform nanostructures.

Branched polyethylenimine-functionalized carbon dots as sensitive and selective fluorescent probes for N-acetylcysteine via an off–on mechanism

A novel fluorescence (FL) analytical method to determine N-acetylcysteine (NAC) was established by using a branched polyethyleneimine-functionalized carbon dot fluorescent system involving FL quenching by Cu²⁺ and subsequent FL recovery upon addition of NAC.

Self-exothermic reaction prompted synthesis of single-layered graphene quantum dots at room temperature

s-GQDs were prepared ultra-rapidly by an efficient self-exothermic reaction and can specifically bind with Al³⁺ to produce an AIEE effect.

Aptamer-modified selenium nanoparticles for dark-field microscopy imaging of nucleolin

Selenium nanoparticles with good water solubility and excellent biocompatibility are used for the first time as a light-scattering nanoprobe with aptamer modification to image nucleolin-overexpressing cancer cells through dark-field microscopy.

Boron and nitrogen co-doped single-layered graphene quantum dots: a high-affinity platform for visualizing the dynamic invasion of HIV DNA into living cells through fluorescence resonance energy transfer

B and N co-doped graphene quantum dots could act as an effective donor in the process of FRET for visualizing the dynamic invasion of HIV DNA into cells.

Plasmon-induced light concentration enhanced imaging visibility as observed by a composite-field microscopy imaging system

The plasmon-induced light concentration (PILC) effect, which has been supposed to be responsible for lots of linear and nonlinear enhanced optical signals such as Raman and high-harmonic generation, is hard to directly observe. Herein, we developed a scattered light based composite-field microscopy imaging (iCFM) system by coupling the oblique and vertical illumination modes, which were adopted in dark- and bright-field microscopy imaging systems, respectively, and through which iCFM system monochromatic background (MCB) images are available, to directly observe the PILC effect in far-field scattering microscopy imaging. Owing to the PILC effect, the scattering signal gain of plasmonic nanoparticles was found to be larger than that of the background, and the imaging visibility of plasmonic nanoparticles was improved by 2.4-fold for silver nanoparticles (AgNPs) and 1.6-fold for gold nanorods (AuNRs). Successful observation of the PILC effect visually together with application in enhanced visibility in cancer cell imaging by this composite illumination system might open an exciting prospect of light scattering microscopy imaging techniques with largely increased visibility.

Synthesis of nitrogen-doping carbon dots with different photoluminescence properties by controlling the surface states

Surface states of carbon dots (CDs) are critical to the photoemission properties of CDs. By carefully adjusting the reaction conditions in a hydrothermal synthesis route, we have prepared a series of CDs with excitation-dependent emission (EDE) and excitation-independent emission (EIE) properties by controlling the content of nitrogen elements, confirming that the characteristic optical properties of CDs originate from their energy levels. It has been found that surface-passivation of the as-prepared CDs by nitrogen doping can improve the emission efficiency and be beneficial to EIE features due to the single electron transition resulting from the single functional groups. And the as-prepared CDs can specifically bind with Hg(2+) with the emission quenched because of the electron transfer from the LUMO levels of CDs to Hg(2+).

Germanium-doped carbon dots as a new type of fluorescent probe for visualizing the dynamic invasions of mercury(II) ions into cancer cells

Carbon dots doped with germanium (GeCDs) were firstly prepared by a new simple 15 min carbonation synthesis route, exhibiting excitation-independent photoluminescence (PL), which could avoid autofluorescence in bioimaging applications. The as-prepared GeCDs have low cell toxicity, good biocompatibility, high intracellular delivery efficiency, stability and could be applied for detection of mercury(II) ions with excellent selectivity in complicated medium. It is to be noted that the as-prepared GeCDs used as a new type of probe for visualization of dynamic invasions of mercury(II) ions into Hep-2 cells display greatly different properties from most of the previously reported CDs which are regularly responsive to iron ions. All the results suggest that the GeCDs can be employed for visualization and monitoring of the significant physiological changes of living cells induced by Hg(2+).

Cytotoxic Edema in Posterior Reversible Encephalopathy Syndrome: Correlation of MRI Features with Serum Albumin Levels

BACKGROUND AND PURPOSE

Posterior reversible encephalopathy syndrome is a clinicoradiologic entity with typical MR imaging showing predominant vasogenic and occasional cytotoxic edema. It is unclear whether MR imaging correlates with levels of serum albumin. We determined potential risk factors for development of cytotoxic edema in posterior reversible encephalopathy syndrome.

MATERIALS AND METHODS

Seventy-nine cases with typical clinical symptoms and characteristic neuroradiologic findings conformed to posterior reversible encephalopathy syndrome diagnostic criteria and were included in this study. FLAIR, DWI, and ADC maps were interpreted to evaluate the severity and type of edema. MR imaging was correlated with the levels of serum albumin, and cytotoxic edema was compared with the location and severity of brain edema.

RESULTS

Pure vasogenic edema was found in 53 cases (67.09%), and vasogenic edema complicated with cytotoxic components, in 26 patients (32.91%). There was no difference in serum albumin levels between patients with cytotoxic components and those with vasogenic edema (P = .983). There was a significant difference in the edema scale scores between patients with cytotoxic edema and those with vasogenic edema (P = .006). The percentage of cytotoxic edema located in the area with higher scale scores of edema was significantly larger than that in areas with lower scale scores of edema (P = .002).

CONCLUSIONS

Serum albumin may contribute to the development of edema in PRES but is not a decisive factor for edema type. Cytotoxic edema in posterior reversible encephalopathy syndrome is probably related to regional decreased perfusion and arteriolopathy. Further work should be undertaken to discover the pathophysiologic mechanisms involved.

Sonocatalytic degradation of RhB over LuFeO3 particles under ultrasonic irradiation

LuFeO3 particles with an average particle size of ∼200 nm were synthesized via a polyacrylamide gel route. The sonocatalytic activity of LuFeO3 particles was evaluated by the degradation of Rhodamine B (RhB) under ultrasonic irradiation, revealing that they exhibit a good sonocatalytic activity. The effects of various experimental factors including ultrasonic frequency (f), reaction solution temperature (T), catalyst dosage (Ccatalyst), initial RhB concentration (CRhB), and pH value on the sonocatalysis efficiency were investigated. It is found that the former four factors have an important influence on the sonocatalytic degradation of RhB, where the best degradation conditions are obtained to be f=60 kHz, T=40 °C, Ccatalyst=4 g L(-1), and CRhB=5 mg L(-1). The pH value has a relatively small effect on the sonocatalytic degradation of RhB compared with other experimental factors. Hydroxyl (·OH) radicals were detected by fluorimetry using terephthalic acid as a probe molecule, revealing that they are produced over the ultrasonic-irradiated LuFeO3 particles. The addition of ethanol leads to a quenching of ·OH radicals and a simultaneous decrease in the RhB degradation. This indicates that ·OH radicals are the primary active species responsible for the dye degradation.

Establishment of reference panel for human platelet antigen genotyping

BACKGROUND AND OBJECTIVES

Human platelet antigens (HPAs) are platelet-specific alloantigens associated with polymorphisms of platelet surface glycoproteins (GPs), and they can induce alloantibodies when individuals lacking a particular polymorphism are exposed to them via pregnancy or transfusion. Immune responses to HPAs are involved in the pathogenesis of several clinical syndromes. HPA genotyping is therefore important for clinical diagnosis and laboratory research. This study aims to establish a reference panel for HPA genotyping.

MATERIALS AND METHODS

Genomic DNA extracted from human blood was used as the template for amplifying HPA (1a-5a and 15a) gene fragments using specific primers. The amplified products were cloned into pGM-T vectors, which were transformed into competent TOP10 cells. After clone screening and amplification, the plasmids were extracted and sequenced. Next, the gene fragments HPA-1b-5b and 15b were obtained by site-directed mutagenesis using the corresponding HPA-1a-5a and 15a plasmids as template DNA.

RESULTS

We successfully constructed reference plasmids for HPA genotyping with HPA-1a-5a, 15a, HPA-1b-5b and 15b. The DNA sequences were consistent with those published in GenBank.

CONCLUSION

Obtaining reference DNA for low-frequency HPAs is very difficult, and the successful construction of reference plasmids for the six HPA systems may solve this problem. Establishment of this panel has laid the foundation for future research on HPA genotyping.

A novel mechanism of NALP3 inducing ischemia reperfusion injury by activating MAPK pathway in acute renal failure

Acute renal failure (ARF) is a rapid loss of kidney function. The reasons and mechanism by which this occurs has not been clarified so far thus creating obstacles to management of this disease. Presently, the experimental research using the accepted renal ischemia reperfusion injury (I/R injury) model represented for ARF focuses on several possible relevant factors such as reactive oxygen species, no-reflow phenomenon, apoptosis and extensive inflammatory response. The latter is much talked about currently. Some intracellular danger sensing proteins, such as the nucleotide binding domain leucine rich repeats-containing family proteins known as NLRs, adjust the inflammatory response through the formation of a multi-protein complex known as an inflammasome. The most classic family member of this complex is NALP3 confirmed to serve as a contributor to I/R injury. However, how it contributes to the pathology remains obscure. The extensive inflammatory response is considered to be modulated by the mitogen-activated protein kinases (MAPK) signaling pathway. NOD2, another family member of NLR, which shares similar structure with NALP3, indicated that it induced the activation of MAPK in response to a pathogen, thus we assumed that NALP3 performed the harmful process of I/R injury, resulting probably from the activation of the MAPK signaling pathway. If this hypothesis proves to be correct, it might benefit the management of ARF.