Nonstoichiometric copper chalcogenides for photo-activated alkyne/azide cycloaddition.

Nonstoichiometric copper chalcogenides with heavy copper vacancies can be used as an effective photo-activated catalyst for the Huisgen [3+2] cycloaddition reaction as Cu(i) can be released corresponding to holes (Cu-defects) under light irradiation. These strategies expand new possibilities for carrying out prototypical click chemistry in the presence of functional groups.

A simple green route to prepare stable silver nanoparticles with pear juice and a new selective colorimetric method for detection of cysteine.

In this work, a new cost-effective, rapid and simple method for the preparation of stable silver nanoparticles (AgNPs) was developed, which can be completed within 15 minutes at room temperature by oxidizing the reductants in pear juice with AgNO3. Compared with the most used citrate-capped AgNPs, the as-prepared AgNPs showed high stability, good biocompatibility and enhanced antibacterial activity. Based on the formation of Ag-S covalent bonds between cysteine and AgNPs as well as the electrostatic interaction of COO(-) and NH4(+) between cysteine molecules, which selectively lead to the aggregation of the as-prepared AgNPs and give a specific yellow-to-red colour change, a new selective colorimetric method for detection of cysteine was proposed with the as-prepared AgNPs by coupling the decrease of the characteristic localized surface plasmon resonance (LSPR) absorption at 406 nm of the as-prepared AgNPs and the increase of the new aggregation-induced band at 530 nm. The ratio of the absorbance at 530 nm to 406 nm (A530/A406) was found to be linearly dependent on the cysteine concentrations in the range of 5.0 × 10(-7) to 1.0 × 10(-5) M with a limit of detection of 6.8 × 10(-8) M.

In Situ Activation of the Receptor Aggregation for Cell Apoptosis by an AI-Au Intelligent Nanomachine via Tumor Extracellular Acidity.

Polyvalent ligand-induced cell receptor aggregation is closely related to cell behavior regulation. At present, most of the means to induce receptor aggregation rely on external stimuli such as light, heat, and magnetic fields, which may cause side effects to normal cells. How to achieve receptor aggregation on the cancer cell surface to achieve cell apoptosis selectively is still a challenge. Therefore, by taking advantage of the unique property of cancer cells' slightly acidic microenvironment, an easy-to-use apoptosis-inducing mode for the in situ activation of cell surface nucleolin clustering has been developed, which not only opened a new channel for nucleolin receptor aggregation to regulate cell function and further development but also avoided damage to normal cells, providing a new strategy for tumor treatment. Dual functional ssDNA (AS1411 aptamer and pH-responsive I-strand sequence) was modified on the surface of gold nanoparticles (AuNPs) to fabricate AI-Au intelligent nanomachines. Then, the specific binding on cancer cells and aggregation of the nucleolin receptors can be achieved via the formation of an i-Motif structure among adjacent AuNPs under the acidic microenvironment. The result showed that AI-Au nanomachines mediated nucleolin cross-linking on the cell surface, resulting in a cytotoxic effect of approximately 60%. Experiments such as calcein-AM/PI staining, nuclear dye staining, and flow cytometry demonstrated that cell apoptosis became more evident with the increase of acidity under the cell surface microenvironment. Immunofluorescence imaging further confirmed the Cyt-c/caspase-3 apoptosis pathway induced by AI-Au nanomachines. The proposed strategy used for specific cancer cell apoptosis by the in situ activation of tumor cell membrane receptor aggregation is inexpensive and simple to use, which not only provides a new means of nucleolin receptor aggregation for regulating cell function but also offers a new strategy for tumor treatment with reduced side effect to normal cells. This work is significant for comprehending the ligand-induced receptor aggregation process and can lead to the development of a promising anticancer drug.

Progressive brain atrophy in Parkinson's disease patients who convert to mild cognitive impairment.

AIMS: Cognitive impairment is a common symptom in the trajectory of Parkinson's disease (PD). However, the pathological underpinning is not fully known. We aimed to explore the critical structural alterations in the process of cognitive decline and its relationships with the dopaminergic deficit and the level of related cerebrospinal fluid (CSF) proteins. METHODS: Ninety-four patients with PD and 32 controls were included in this study. Neuropsychological tests were performed at baseline and after 28 months to identify which patients had normal cognition and which ones developed PD-MCI after follow-up ("converters"). Gray matter atrophy was assessed in cross-sectional and longitudinal analyses, respectively. The associations between altered GMV with dopamine transporter (DAT) results and the level of CSF proteins were assessed. RESULTS: Among the 94 patients with normal cognition at baseline, 24 (mean age, 63.1 years) developed PD-MCI after 28 months of follow-up, and 70 (mean age, 62.3 years) remained nonconverters. The converters showed significant right temporal atrophy at baseline and extensive atrophy in temporal lobe at follow-up. Progressive bilateral frontal lobe atrophy was found in the converters. Baseline right temporal atrophy was correlated with the striatal dopaminergic degeneration in the converters. No correlation was found between the right temporal atrophy and the alterations of CSF proteins. CONCLUSION: Early atrophy in temporal lobes and progressive atrophy in frontal lobes might be a biomarker for developing multidomain impairment of cognition and converting to PD-MCI. Furthermore, cognition-related temporal atrophy might be associated with dopaminergic deficit reflected by DAT scan but independent of CSF proteins in patients with PD who convert to PD-MCI.

1-Cyclo-propyl-6-fluoro-7-(4-nitro-so-piperazin-1-yl)-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid.

The title compound, C(17)H(17)FN(4)O(4), is a derivative of ciprofloxacin [1-cyclo-propyl-6-fluoro-4-oxo-7-(1-piperazin-yl)-1,4-dihydro-quinoline-3-carboxylic acid]. The crystal packing is stabilized by inter-molecular C-H⋯O hydrogen bonds together with π-π electron ring inter-actions [centroid-centroid separations between quinoline rings of 3.5864 (11) and 3.9339 (13) Å]. A strong intra-molecular O-H⋯O hydrogen bonds is present as well as an intra-molecular C-H⋯F inter-action.

Facile one-pot synthesis of folic acid-modified graphene to improve the performance of graphene-based sensing strategy.

A convenient and environment-friendly method is reported to synthesize the reduced graphene oxide (rGO) sheets in aqueous solution using folic acid (FA) as both a reducing and stabilizing agent, to improve the performance of graphene-based sensing strategy. The as-prepared FA-rGO sheets were characterized by transmission electron microscopy (TEM), UV-vis absorption spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA), which provided the clear identification of the removal of oxygen-containing functional groups from the graphene oxide (GO) to form FA-rGO sheets. Further, it was found that the obtained FA-rGO sheets exhibited better biocompatibility and could act as the more efficient energy acceptor in long range resonance energy transfer (LrRET) process than that of graphene. Additionally, the FA-rGO can also catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2, and compared with GO sheets, they exhibited the more prominent intrinsic peroxidase-like activity, thus providing the more sensitive approach for colorimetric detection of H2O2.

Quality of reporting of systematic reviews published in "evidence-based" Chinese journals.

BACKGROUND: The number of systematic reviews (SRs)/meta-analyses (MAs) has increased dramatically in China over the past decades. However, evaluation of quality of reporting of systematic reviews published has not been undertaken. The objective of this study is to evaluate the quality of reporting of SRs/MAs assessing efficacy and/or harms of clinical interventions published in "evidence-based" Chinese journals. METHODS: Web-based database searches were conducted for the Chinese Journal of Evidence-based Medicine, the Journal of Evidence-Based Medicine, the Chinese Journal of Evidence Based Pediatrics, and the Chinese Journal of Evidence-Based Cardiovascular Medicine. SRs/MAs assessing efficacy and/or harms of clinical interventions were included. The cut-off was December 31st 2011. The PRISMA statement was applied to assess the quality of reporting. Each item was assessed as follows: 'Yes' for total compliance, scored '1'; 'partial' for partial compliance, scored '0.5'; and 'No' for non-compliance, scored '0'. The review was considered to have major flaws if it received a total score of ≤15.0, minor flaws if it received a total score of 15.5 to 21.0, and minimal flaws if it received a total score 21.5 to 27.0. Odds ratios were used for binary variables, and the mean difference was used for continuous variables. Analyses were performed using RevMan 5.0 software. RESULTS: Overall, 487 SRs/MAs were identified and assessed. The included reviews had medium quality with minor flaws based on PRISMA total scores (range: 8.5-26.0; mean: 19.6 ± 3.3). The stratified analysis showed that SRs/MAs with more than 3 authors, from a university, hospital + university cooperation, multiple affiliations (≥2), and funding have significantly higher quality of reporting of SRs/MAs; 58% of the included reviews were considered to have minor flaws (total score of 15.6 to 21.0). Only 9.6% of reviews were considered to have major flaws. Specific areas needing improvement in reporting include the abstract, protocol and registration, and characteristics of the search. CONCLUSIONS: The reporting of SRs published in "evidence-based" Chinese journals is poor and needs to be improved in order for reviews to be useful. SR authors should use the PRISMA checklist to ensure complete and accurate accounts of their SRs.

A surfactant-assisted redox hydrothermal route to prepare highly photoluminescent carbon quantum dots with aggregation-induced emission enhancement properties.

Highly PL carbon quantum dots (CQDs) were successfully prepared from C60 by introducing CTAB and H2O2 in aqueous NaOH under hydrothermal conditions. The CQDs displayed a nanoparticle aggregation-induced emission enhancement (NP-AIEE).