Zwitterionic Thiolate-Protected Ag22(0/I) and Ag20(I) Clusters: Assembly, Structural Characterization, and Antibacterial Activity.

Zwitterionic thiolate ligands have the potential to introduce novel assembly modes and functions for noble metal clusters. However, their utilization in the synthesis of silver clusters remains understudied, particularly for the clusters containing reductive Ag(0) species. In this article, we report the first synthesis of a mixed-valence silver(0/I) cluster protected by zwitterionic Tab as thiolate ligands (Tab = 4-(trimethylammonio)benzenethiolate), denoted as [Ag22(Tab)24](PF6)20·16CH3OH·6Et2O (Ag22·16CH3OH·6Et2O), alongside an Ag(I) cluster [Ag20(Tab)12(PhCOO)10(MeCN)2(H2O)](PF6)10·11MeCN (Ag20·11MeCN). Ag22 has a distinct hierarchical supratetrahedral structure with a central {Ag6} kernel surrounded by four [Ag4(Tab)6]4+ units. High-resolution electrospray ionization mass spectra demonstrate that Ag22 has two free electrons, indicating a superatomic core. Ag20 has a drum-like [Ag12(Tab)6(PhCOO)6(H2O)]6+ inner core capped by two tetrahedral-like [Ag4(Tab)3(PhCOO)2(MeCN)]2+ units. Ag20 can be transformed into Ag22 after its reaction with NaBH4 in solution. Antibacterial measurements reveal that Ag22 has a significantly lower minimum inhibitory concentration than that of the Ag20 cluster. This work not only extends the stabilization of silver(0/I) clusters to neutral thiol ligands but also offers new materials for the development of novel antibacterial materials.

A comparison of mycophenolate mofetil and calcineurin inhibitor as maintenance immunosuppression for kidney transplant recipients: A meta-analysis of randomized controlled trials

Background/aim: We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the comparison and its timing between mycophenolate mofetil (MMF) and calcineurin inhibitor (CNI) as maintenance immunosuppression for kidney transplant recipients. Materials and methods: The RCTs of MMF versus CNI as maintenance immunosuppression for kidney transplant recipients were searched from PubMed, Embase, Cochrane Central Register of Controlled Trials (CCRCT), and ClinicalTrials.gov. After screening relevant RCTs, two authors independently assessed the quality of included studies and performed a meta-analysis using RevMan5.3. Relative risk (RR) was used to report dichotomous data, while mean difference (MD) with 95% confidence interval (CI) was used to report continuous outcomes. The analysis was conducted using the random-effect model due to the expected heterogeneity among different studies. Four subgroups were allocated to compare MMF with CNI as maintenance immunosuppression: (1) after 3 months of CNI-based therapy, (2) after 6 months of CNI-based therapy, (3) after 12 months of CNI-based therapy, and (4) in recipients with allograft dysfunction. Results: Twelve RCTs with 950 renal transplant recipients were included. This meta-analysis presented the following results upon comparison between MMF and CNI as maintenance immunosuppression for kidney transplant recipients: (1) MMF significantly improved the glomerular filtration rate (GFR) not only in the comparison performed after 3, 6, or 12 months of CNI-based therapy but also in the comparison of recipients with allograft dysfunction, (2) MMF may increase the risk of acute rejection in the comparison performed after 3 months of CNI-based therapy, but no increase was noted in the comparison performed after 6 or 12 months of CNI- based therapy. Conclusion: Our present meta-analysis suggested that MMF followed at least 6 months of CNI-based therapy is an effective maintenance immunosuppressive regimen for kidney transplant recipients to improve renal function but not increase rejection.

Remote Ischemic Preconditioning Reduces the Risk of Contrast-Induced Nephropathy in Patients with Moderate Renal Impairment Undergoing Percutaneous Coronary Angiography: A Meta-Analysis.

BACKGROUND/AIMS: This meta-analysis evaluated the effects of remote ischemic preconditioning (RIPC) on the risk of contrast-induced nephropathy (CIN) in patients undergoing percutaneous coronary intervention/coronary angiography (PCI/CA). METHODS: PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases were searched for randomized controlled trials (RCTs) that assessed the effect of RIPC on CIN in patients undergoing PCI/CA. The main outcomes of interest were the incidence of CIN 48-72 h after CA, the levels of serum creatinine, cystatin C, neutrophil gelatinase-associated lipocalin, and estimated glomerular filtration rate (eGFR), mortality, and requirement of hemodialysis and rehospitalization. The analysis was conducted using the random-effect model due to the expected heterogeneity among different studies. RESULTS: In total, 16 trials covering 2,048 patients were identified. By assessing the methodological quality of the included studies through the Coch-rane risk of bias, we found that of the 16 RCTs, 3 had a low risk of bias, 6 a high, and 7 an unclear risk. The application of RIPC decreased the incidence of CIN (relative risk, RR, 0.50, 95% confidence interval, CI, 0.39-0.65; p < 0.001). Subgroup analyses showed that RIPC decreased the incidence of CIN in patients with eGFR <60 mL/min/1.73 m2 (RR 0.53, 95% CI 0.38-0.75; p < 0.001) but not in patients with eGRF ≥60 mL/min/1.73 m2 (RR 0.82, 95% CI 0.35-1.94; p = 0.66) at baseline. Furthermore, the increase in serum creatinine was significantly lower in patients with RIPC compared to control patients (standardized mean difference -1.41, 95% CI -2.46 to -0.35; p = 0.009). CONCLUSIONS: Based on 16 RCTs, this meta-analysis shows that RIPC can reduce the risk of CIN in patients with moderate renal impairment undergoing PCI/CA. However, this needs to be confirmed by further high-quality evidence.

Maintenance therapy for lupus nephritis with mycophenolate mofetil or azathioprine. A meta-analysis
.

AIM: Maintenance therapy for lupus nephritis (LN) remains controversial. This meta-analysis of randomized controlled trials (RCTs) describes the comparative benefits and safety of mycophenolate mofetil (MMF) versus azathioprine (AZA) as maintenance therapy in patients with LN. MATERIALS AND METHODS: RCTs that compared the maintenance regimens of MMF and AZA in the treatment of LN were included. Outcomes were mortality, end-stage renal disease (ESRD), renal relapse, doubling of serum creatinine, and adverse effects. We performed the meta-analysis using Review Manager software (version 5.3). RESULTS: Seven RCTs were included in the meta-analysis. There were no significant differences between the MMF and AZA groups in regards to mortality, relapse, ESRD, doubling of serum creatinine, infection, or gastrointestinal upset. However, the MMF group incurred lower risks of leukopenia (RR = 0.16, 95% CI = 0.06 - 0.40; p = 0.0001) and amenorrhea (RR = 0.23, 95% CI = 0.09 - 0.59, p = 0.002) compared with the AZA group. CONCLUSION: MMF seems more effective than AZA as maintenance therapy for LN although the differences did not reach statistical significance. Furthermore, the MMF group incurred lower risk of leukopenia than AZA. However, more RCTs are needed to confirm the conclusion.

Prognostic value of plasma NT-proBNP levels in very old patients with moderate renal insufficiency in China.

BACKGROUND: The N­terminal pro-brain natriuretic peptide (NT-proBNP) has an important prognostic value in chronic renal insufficiency; however, most studies have been conducted in patients with end-stage renal disease (ESRD). In this study we evaluated the prognostic significance of NT-proBNP in very old patients with stage 3 chronic kidney disease (CKD) and compared its prognostic value in CKD3a versus CKD3b patients. METHODS: Patients (age ≥80 years old) hospitalized with stage 3 CKD from 2007 to 2010 who were eligible for this prospective study underwent follow-up examinations in 2015. The examinations included measurements of anthropometric characteristics, blood pressure, plasma NT-proBNP, creatinine, and lipids. End-point events were all-cause death and major adverse cardiac events (MACEs). RESULTS: A total of 168 patients (mean age 87.4 ± 2.9 years, range 80-99 years) were included in the analysis (CKD3a, n = 117; CKD3b, n = 51). The results showed that CKD3b was associated with lower hemoglobin levels, higher NT-proBNP levels and a higher rate of hypertension compared with CKD3a. After a median follow-up of 3.8 years (interquartile range 1.5-6.1 years), a higher NT-proBNP level was associated with a higher risk of all-cause death (hazard ratio HR 1.986, 95% confidence interval CI 1.276-2.819, p = 0.028) and MACEs (HR 2.872, 95% CI 1.241-6.644, p = 0.014) after adjusting for age, sex, and traditional risk factors; however, a subgroup comparison showed that elevated NT-proBNP levels were associated with a higher risk of all-cause death (HR 2.350, 95% CI 1.906-6.091, p = 0.039) and MACEs (HR 3.025, 95% CI 1.024-8.940, p = 0.045) in CKD3a but not CKD3b. CONCLUSION: Levels of NT-proBNP increased with decreased renal function in very old patients with stage 3 CKD; therefore, NT-proBNP is an independent predictor for all-cause death and MACEs in these patients but has a greater prognostic value in CKD3a than in CKD3b.

Multitarget therapy versus intravenous cyclophosphamide in the induction treatment of lupus nephritis: a metaanalysis of randomized controlled trials

Background/aim: Multitarget therapy for lupus nephritis (LN) remains in its exploratory phrase and the recent evidence is insufficient. This study aimed to evaluate the efficacy and safety of mycophenolate mofetil (MMF), tacrolimus (TAC), and steroids (multitarget therapy) versus intravenous cyclophosphamide (IVC) and steroids in induction treatment of LN. Materials and methods: We searched for randomized controlled trials of MMF plus TAC versus IVC in LN using PubMed, EMBASE, the Cochrane Central Register of Controlled Trials, the China Biology Medicine Database, and the China National Knowledge Infrastructure Database. We assessed the retrieved citations and selected studies according to predefined inclusion and exclusion criteria. Results: In total, we identified 8 trials including 801 patients. The metaanalysis revealed that overall multitarget therapy is more effective at inducing complete renal remission compared with IVC (RR: 1.94, 95% CI: 1.61-2.33; P < 0.00001). In terms of LN classification, multitarget therapy exhibited superiority compared with IVC for inducing complete remission of class IV LN (RR: 1.52, 95% CI: 1.10- 2.08; P = 0.01), class V LN (RR: 4.24, 95% CI: 1.30-13.88; P = 0.02), and class V+IV LN (RR: 2.29, 95% CI: 1.45-3.62; P = 0.0004); however, no superiority was noted for class III LN or class V+III LN. The rates of gastrointestinal symptoms, abnormal liver function, leukopenia, and irregular menstruation were significantly reduced in the multitarget therapy group compared with the IVC group for LN. Nevertheless, the multitarget therapy group more frequently exhibited new-onset hypertension compared with the IVC group. Conclusion: Multitarget therapy is more effective than IVC in the induction treatment of LN in Chinese patients and exhibits a better safety profile.

Calcitriol in the treatment of IgA nephropathy with non-nephrotic range proteinuria: a meta-analysis of randomized controlled trials
.

OBJECTIVE: The aim of the present study was to investigate the efficacy and safety of calcitriol for treating Chinese patients with IgA nephropathy presenting as non-nephrotic range proteinuria, and a comprehensive meta-analysis was conducted using the related randomized controlled trials (RCTs). METHODS: We searched for RCTs of calcitriol for the treatment of IgA nephropathy in the CNKI, CBM, Cochrane Central Register of Controlled Trials, PUBMED, and EMBASE databases. The studies included in our meta-analysis were strictly determined according to the inclusion and exclusion criteria. We evaluated the quality of the included studies using the Jadad score sheet and performed the meta-analysis using RevMan software (version 5.30). RESULTS: Our meta-analysis, which included 7 RCTs involving 310 Chinese participants, showed that calcitriol contributed to a decrease in proteinuria standard mean difference (SMD) -1.49, 95% CI (-2.37, -0.62); p = 0.0008). No significant differences were observed in serum creatinine (SMD -0.13, 95% CI (-0.53, 0.27); p = 0.52), serum calcium (SMD 0.28, 95% CI (-0.08, 0.65); p = 0.13), or serum phosphorus (SMD 0.03, 95% CI (-0.07, 0.14); p = 0.57) levels. All of the adverse reactions mentioned in these studies were mild. CONCLUSION: These data indicated that calcitriol is a promising treatment to reduce proteinuria in Chinese patients with IgA nephropathy presenting as non-nephrotic range proteinuria, and it has only mild side effects.
.

Polyhedral {Ag12} and {Ag16} Clusters: Synthesis, Structural Characterization and Third-Order Nonlinear Optical Properties.

Two polyhedral silver-thiolate clusters, [S@Ag16(Tab)10(MeCN)8](PF6)14 (Ag16) and [Ag12(Tab)6(DMF)12](PF6)12 (Ag12), were synthesized by using electroneutral Tab species as protective ligands (Tab=4-(trimethylammonio)benzenethiolate, DMF=N,N-dimethylformamide, MeCN=acetonitrile). Ag16 has a decahedral shape composed of eight pentagon {Ag5} units and two square {Ag4} units. The structure of Ag12 is a cuboctahedron, a classical Archimedean structure composed of six triangular faces and eight square faces. The former configuration is discovered in silver-thiolate cluster for the first time, possibly benefited from the more flexible coordination between the Tab ligand and Ag+ facilitated by the electropositive -N(CH3)3 + substituent group. Third-order nonlinear optical studies show that both clusters in DMF exhibit reverse saturate absorption response under the irradiation of 532 nm laser.

[Classification of Cimicifuga species based on 1H-NMR fingerprint combined with pattern recognition technique].

The metabolomic analysis of three Cimicifuga species was performed using H-NMR spectroscopy and pattern recognition (PR) techniques. A broad range of metabolites could be detected by 'H-NMR spectroscopy without any chromatographic separation. The analysis using principal component analysis (PCA) and discriminant partial least square (DPLS) of the 1H-NMR spectrum showed a clear discrimination between C. foetida and the other two species. The major metabolites responsible for the discrimination were triterpenoid saponins and saccharides. These results indicated that the combination of 1H-NMR and PR provides a useful tool for chemotaxonomic analysis and authentification of Cimicifuga species, and could used for the quality control of plant materials.

Preparation of a shared chip for cell capturing and imaging with nanoparticle scaffold, nanogap and circulating tumor cell detection.

Aim: To achieve accurate detection of circulating tumor cells (CTCs) in a large-volume sample. Materials & methods: Silica nanoparticles were crosslinked layer-by-layer on glass slides as the substrate of a chip using polyacrylic acid. Polyacrylic acid was immobilized as a spacer and capture ligands were immobilized on the spacer. Results: The chip can be integrally applied to capture, post-treatment and imaging detection for CTCs. The detected cell numbers were 33 and 40 for 9 cell/ml samples and clinical blood samples (7.5 ml), respectively. The detection ratio of positive samples was 100%. Conclusion: The significantly increased detected number for CTCs indicates that this methodology may avoid or greatly reduce the false-negative ratio of positive clinical samples.

Detection of DNA based on fluorescence resonance energy transfer of polyelectrolyte-protected CdTe quantum dots as energy donors.

The approach for DNA detection was established by using a fluorescence resonance energy transfer (FRET) system, in which the energy donor was poly-diallyldimethylammonium chloride-protected quantum dots and the energy receptor was ethidium bromide (EB) inserting into the double stranded DNA. The concentration of the probe DNA, EB and NaCl was optimized. Under the optimized conditions, the FRET system has a stable signal and good reproducibility. The linear range is 7.7-61.6 nM with the correlation coefficient of 0.998 and the limit of detection is 7.7 nM. This method is simple and sensitive, and makes the label-free DNA detection come true.

Typing and determination of SNP functional gene based on highly selective and signal-amplified fluorescence double-probe with the help of ExoIII nuclease and magnetic bead.

We have developed a fluorescence double-probe detection system with signal amplification for simple typing and determination of single nucleotide polymorphism (SNP) functional gene based on non-sequence dependence of ExoIII nuclease on dsDNA and rapid separation of magnetic bead. Matched detected gene can cyclically release abundant fluorescence-labeled ssDNA from the probe and the corresponding measured fluorescence signal is amplified up to 6063 times. In this case, the probe cannot release the measured fluorescence signal for the point mutation gene and then the corresponding measured signal is inhibited. According to signal amplification and inhabitation of the probe, we proposed both an accurate genotyping approach with strong specificity and a sensitive determination approach with high selectivity for SNP functional gene. For qualitative genotyping, there are obvious genotype-based differences of measured fluorescence phenotypes among three kinds of the samples of the investigated SNP. The quantitative determinations of its wild-type gene and mutant gene have all a good linearity in the range from 0.5 to 500 pmol/L with the correlation coefficients R2 of 0.9940 and 0.9911, and a high sensitivity with the detection limits of 0.11 and 0.20 pmol/L, respectively. Compared to the usual single-probe detection system, the developed double-probe system can achieve not only accurate genotyping but also the sensitive gene determination. Meanwhile, it is also a simple and reliable method for both quantitative and qualitative analysis of functional gene.

Fabrication of surface charge pH-sensitive multi-bumpy small magnetic bead with ultrahigh magnetic content and its ultrahigh loading capacity and salt-free rapid isolation for DNA.

Gene transfection vector polyethyleneimine (PEI) was used as a cross-linking agent to crosslink the surface epoxidized magnetic nanoparticles and aggregate them to form a small magnetic bead (MB) with multiple nanoscale bumps on its surface (i.e. the multi-bumpy small magnetic bead, mbsMB). As there is a very low content of non-magnetic components (the cross-linking agent) in the magnetic bead, the mbsMB has an ultrahigh magnetic content of 81.95 % and a smaller particle size of 1.4 µm when compared with the usual medical MB. Such a small MB also has a strong magnetic force allowing it to reach the rapid separating ability of the commonly used larger medical MB which has 8 times its volume. The mbsMB has an obvious pH sensitivity of positive and negative surface charges and the salt-free isolation of DNA has been achieved based on the electrostatic interactions between mbsMB and DNA. This avoids the desalting of the isolated DNA as well as the effects of high salt concentration on its long chain helix structure. Whether in an acidic absorbing medium, an alkalinous desorbing one or a near neutral particle-storing one, the mbsMB will have obvious surface electrostatic charges. There is also its good suspension stability in an aqueous medium which provides a good condition for isolating of DNA suitable for efficiently adsorbing and desorbing. The as-prepared MB has a unique surface structure and some excellent properties, all suitable for adsorbing DNA. In addition, a large amount of commonly used gene transfection vector PEI can be cross-linked and bonded on the surface of mbsMB, whilst still having an excellent DNA-loading ability. In summary, the mbsMB has an ultrahigh capacity of 629.49 mg/g for DNA load.

Typing SNP based on the near-infrared spectroscopy and artificial neural network.

Based on the near-infrared spectra (NIRS) of the measured samples as the discriminant variables of their genotypes, the genotype discriminant model of SNP has been established by using back-propagation artificial neural network (BP-ANN). Taking a SNP (857G>A) of N-acetyltransferase 2 (NAT2) as an example, DNA fragments containing the SNP site were amplified by the PCR method based on a pair of primers to obtain the three-genotype (GG, AA, and GA) modeling samples. The NIRS-s of the amplified samples were directly measured in transmission by using quartz cell. Based on the sample spectra measured, the two BP-ANN-s were combined to obtain the stronger ability of the three-genotype classification. One of them was established to compress the measured NIRS variables by using the resilient back-propagation algorithm, and another network established by Levenberg-Marquardt algorithm according to the compressed NIRS-s was used as the discriminant model of the three-genotype classification. For the established model, the root mean square error for the training and the prediction sample sets were 0.0135 and 0.0132, respectively. Certainly, this model could rightly predict the three genotypes (i.e. the accuracy of prediction samples was up to 100%) and had a good robust for the prediction of unknown samples. Since the three genotypes of SNP could be directly determined by using the NIRS-s without any preprocessing for the analyzed samples after PCR, this method is simple, rapid and low-cost.

Polyelectrolyte-protected Dual-color-quantum-dot Assembled Silica Nanoparticles and Their Application in Simultaneous Fluorescence Determination of e Antigen and Surface Antigen of Hepatitis B.

Cationic poly-diallyldimethylammonium (PDADMAC), green CdTe quantum dots (QDs) or red CdS coated CdTe QDs, and anionic polyacrylic acid (PAA) were respectively assembled on the nano-carrier SiO2 to prepare green fluorescence composite nanoparticles (GF-QDs) and red ones (RF-QDs) with the structure SiO2/PDADMAC/QD/PDADMAC/PAA. The sandwich structure "PDADMAC/QD/PDADMAC" on the nano-carrier not only realized the protection to fluorescence of QDs but also avoided the fluorescence shielding of silica shell for the assembled QDs. In 7 days, the diluent solutions of GF-QD and RF-QD all have a very stable fluorescence. On the contrary, the fluorescence of diluent solutions of red and green QDs reduced by 75.99 and 94.35%, respectively. Indeed, they have not fluorescent shielding and have a very slight fluorescent enhancement. Based on GF-QD and RF-QD, the simultaneous determination of Hepatitis B e antigen and surface antigen has been established. Their determination in buffer and plasma all showed good precision and accuracy.

Emissive intelligent supramolecular gel for highly selective sensing of Al3+ and writable soft material.

A fluorine-containing acylhydrazone was newly designed and found to form gels in a mixed solvent of DMSO-ethylene glycol. The gelator could show brilliant blue light upon mixing with Al3+, which could be erased by F- ions and thus forming an erasable gel.

Chemometric classification of traditional Chinese medicines by their geographical origins using near-infrared reflectance spectra.

Some raw materials that have different places of production for the plant sources of the drugs Astragalus membranaceus and ginseng have been studied, based on their near-infrared reflectance spectra. The experimentally recorded spectra represent heavily ill-posed and highly correlative data sets. Three related methods, i.e. the Fisher linear discriminant analysis (FLDA), the ridge-type linear discriminant analysis (RLDA) and a newly proposed penalized ridge-type linear discriminant analysis (PRLDA), have been investigated. FLDA over-fits for the training objects of the two data sets to a high extent and is unstable for the predictive objects of the two data sets. RLDA shows obvious improvement in terms of over-fitting and unstability, but the stability for the predictive objects of the two data sets is too sensitive to their ridge-type penalized weights, tending to produce erroneous discrimination results. The proposed PRLDA can circumvent the two aforementioned problems with a large domain of penalized weights for correct discriminant analysis of the two data sets studied. The combination of the PRLDA method and near infrared reflectance spectroscopy can be adapted for the discrimination of the production places of plant sources of these drugs.

Polyelectrolyte-based electrochemiluminescence enhancement for Ru(bpy)3²âº loaded by SiO2 nanoparticle carrier and its high sensitive immunoassay.

In this paper the strong electrochemiluminescence (ECL) nanoparticles have been prepared based on the anionic polyelectrolyte sodium polyacrylate (PAA)-ECL enhancement for Ru(bpy)3(2+), which were loaded by the carrier of SiO2 nanoparticle. There were two kinds of Ru(bpy)3(2+) for the as-prepared nanoparticles, the doped one and the exchanged one. The former was loaded inside the ECL nanoparticles by doping, in a form of ion-pair macromolecules PAA-Ru(bpy)3(2+). The corresponding ECL was enhanced about 2 times owing to the doping increase of Ru(bpy)3(2+). The latter was loaded on the PAA-doped Nafion membrane by ion exchange. The corresponding ECL was enhanced about 3 times owing to the ion-exchanging increase of Ru(bpy)3(2+). At the same time, ECL intensity of the doped-inside Ru(bpy)3(2+) was further enhanced 13 times because polyelectrolyte PAA in the doped membrane could obviously enhance electron transfer between the doped Ru(bpy)3(2+) and the working electrode. Furthermore, based on hydrophobic regions of the doped membrane antibody labeling could be easily realized by the as-prepared nanoparticles and then a high sensitive ECL immunoassay for HBsAg was developed. The linear range was between 1.0 and 100 pg mL(-1) (R(2)=0.9912). The detection limit could be as low as 0.11 pg mL(-1) (signal-to-noise ratio=3).

Competitive interactions of adriamycin and ethidium bromide with DNA as studied by full rank parallel factor analysis of fluorescence three-way array data.

The competitive interactions of adriamycin (AMC) and a fluorescence probe of ethidium bromide (EB) with DNA have been studied by full rank parallel factor analysis (FRA-PARAFAC) of fluorescence excitation-emission three-way data array. The excitation and emission spectra as well as the equilibrium concentrations of co-existing species in different reaction mixtures can be directly obtained by the FRA-PARAFAC treatment. The concordance of the resolved excitation and emission spectra of AMC, EB and EB-DNA with the standard spectra of these species confirmed the reliability of the equilibrium concentrations of these components in the reaction mixtures studied. The results obtained are valuable for providing a deeper insight into the competitive interaction mechanism of AMC and EB with DNA. The conclusion was directly given out that the interaction of AMC with DNA is the intercalating model. The FRA-PARAFAC method as exemplified by the present study provides an useful approach for studying the interaction of clinical drugs with DNA in the presence of disturbance of drug assistants.

Preparation of strongly fluorescent silica nanoparticles of polyelectrolyte-protected cadmium telluride quantum dots and their application to cell toxicity and imaging.

Based on the polyelectrolyte-protected CdTe quantum dots (QDs), which were prepared by self-assembling of QDs and poly-diallyldimethylammonium chloride (PDADMAC) in the help of electrostatic attraction, the strong fluorescence silica nanoparticles (QDs-PDADMAC@SiO(2)) have been prepared via a water-in-oil reverse microemulsion method. Transmission electron microscopy and Zeta potential analysis were used to characterize the as-prepared nanoparticles. All of the particles were almost spherical and there is a uniform distribution of the particle size with the average diameter about 25 nm. There is a large Zeta potential of -35.07 mV which is necessary for good monodispersity of nanoparticles solution. As compared with the QDs coated by SiO(2) (QDs@SiO(2)), the QDs-PDADMAC@SiO(2) nanoparticles have much stronger fluorescence, and their fluorescence stability could be obviously improved. Moreover, QDs-PDADMAC@SiO(2) exhibits good biological compatibility which promotes their application in cellular imaging.