GRP78 protein metabolism in obese and diabetic rats: a study of its role in metabolic disorders.

OBJECTIVE: This study aimed to compare and analyze the expression and significance of the GRP78 protein in cochlear cell injury induced by a high glucose and high-fat diet in obese and diabetic rats. METHODS: Male SD rats were randomly divided into two groups: normal (NC) and high-fat (HF) groups. The NC group was fed a standard diet for eight weeks, while the HF group received a high-glucose, high-fat diet. The HF group was further categorized into the obesity group (OB group) and the type II diabetes mellitus group (T2DM group). To induce a type II diabetes mellitus (T2DM) model, the T2DM group received an intraperitoneal injection of a small dose of STZ (45 mg/kg). After four weeks on the original diet, body weight, blood glucose, blood lipid levels, and auditory brainstem response (ABR) thresholds were measured. The cochlea was dissected, and its morphology was observed using HE staining. Immunohistochemistry and western blotting were utilized to examine the expression level of the GRP78 protein in the cochlea. RESULTS: (1) The ABR threshold demonstrated a statistically significant difference between the T2DM group and the OB group (P < 0.05), as well as between the OB group and the NC group (P < 0.05). (2) Based on morphological comparisons from HE-stained sections, the T2DM group exhibited the most significant alterations in the number of cells in the spiral ganglion, the organ of Corti, and the stria vascularis of the cochlea. (3) The expression level of the GRP78 protein in the cochlea was higher in the T2DM group compared to the OB group (P < 0.05) and higher in the OB group compared to the NC group (P < 0.05). CONCLUSION: The findings indicate that the GRP78 protein plays a role in hearing loss caused by T2DM and hyperlipidemia. Moreover, T2DM is more likely than hyperlipidemia to be associated with hearing impairment.

[Regional CT value in prediction of proximal femoral fracture].

OBJECTIVE: To investigate CT values of cancellous bone in femoral neck in adults over 60 years with proximal femoral fractures. METHODS: From January 2020 to December 2020, a retrospective analysis was performed on 280 subjects aged 60 years or older who underwent bilateral hip CT examination, including 85 males and 195 females, 120 on the left side and 160 on the right side, aged 75 (66, 82) years old. One hundred thirty-six patients with proximal femoral fractures were included in study group and 144 patients without fractures were included in control group. GEOptima CT was used to scan and reconstruct horizontal, coronal and sagittal layers of proximal femur. CT values of cancellous bone in femoral neck were measured and compared between two groups. The relationship between CT values of cancellous bone of femoral neck and proximal femoral fracture was analyzed statistically. RESULTS: In terms of age, fracture group aged 79(73.3, 85.0) years old, non-fracture group aged 69.5 (64.0, 78.8) years old, and had significant difference in age between two groups (P<0.05). In terms of CT value, regional CT value in fracture group was 8.62(-3.62, 27.15) HU, which was lower than that in non-fracture group 34.31(-5.93, 71.74) HU(P<0.05). CT value on coronal view in fracture group was -8.48(-30.96, 17.46) HU, which was lower than that in non-fracture group 40.49(5.55, 80.71) HU (P<0.05). CT value on sagittal view in fracture group was -31.28(-54.91, -5.11) HU, which was lower than that in non-fracture group 7.74(-20.12, 44.54) HU (P<0.05). CT values on horizontal view in fracture group was 0.17(-23.13, 24.60) HU, which was lower than that in non-fracture group 46.40(10.42, 85.18) HU(P<0.05). The mean regional CT values among three planes in the fracture group were lower than those in the non-fracture group. Logistic regression analysis showed coronal CT value was influencing factors of proximal femoral fracture, and it could be written into regression equations that predict probability of fracture. CONCLUSION: In adults aged over 60 years old, CT values of cancellous bone of femoral neck decreased with increasing age. The smaller CT value of cancellous bone of femoral neck, the greater risk of proximal femoral fracture.

The anti-leukemia activity and mechanisms of shikonin: a mini review.

Leukemia encompasses a group of highly heterogeneous diseases that pose a serious threat to human health. The long-term outcome of patients with leukemia still needs to be improved and new effective therapeutic strategies continue to be an unmet clinical need. Shikonin (SHK) is a naphthoquinone derivative that shows multiple biological function includes anti-tumor, anti-inflammatory, and anti-allergic effects. Numerous studies have reported the anti-leukemia activity of SHK during the last 3 decades and there are studies showing that SHK is particularly effective towards various leukemia cells compared to solid tumors. In this review, we will discuss the anti-leukemia effect of SHK and summarize the underlying mechanisms. Therefore, SHK may be a promising agent to be developed as an anti-leukemia drug.

The effect of Tianjiang Xueshuantong Wan pills on ischemia-reperfusion injury after thrombolysis in acute cerebral infarction.

OBJECTIVE: The aim of this study is to investigate the effect of Tianjiang Xueshuantong Wan pills on reperfusion injury after venous thrombolysis in acute cerebral infarction. METHODS: The strategy used in this study is a randomised controlled clinical trial. In total, 72 cases were included, with 36 in the trial group and 36 in the control group, with a 1:1 ratio. Both groups were given standardised treatment for acute cerebral infarction. Based on the rt-PA intravenous thrombolysis, the test group took Tianjiang Xueshuantong Wan pills orally, whereas the control group solely utilised rt-PA for intravenous thrombolysis and did not take the test medicine orally. The patients' intracranial hemorrhage was clarified by head CT scan, and the occurrence of reperfusion injury was recorded during the entire trial. RESULTS: There were no significant differences in serum IL-6, MDA, SOD and TNF concentrations and NIHSS scores between the two groups before therapy (P > 0.05). After treatment, the serum concentrations of IL-6, MDA and TNF in the experimental group were significantly decreased compared with the control group, while the serum concentrations of SOD were significantly increased compared with the control group, with statistical significance (P > 0.05). After seven days of treatment, the total effective rate in the experimental group was 88.89%, while the data in the control group was 75%. There was a statistically significant difference between the experimental and control groups. CONCLUSION: Tianjiang Xueshuantong Wan pills can effectively prevent reperfusion injury following intravenous thrombolysis in individuals with cerebral infarction while improving patients' neurological deficits.

[Application of porous tantalum Jumbo cup in revision of hip arthroplasty].

OBJECTIVE: To investigate the clinical effect of porous tantalum Jumbo cup on acetabular reconstruction in revision of total hip arthroplasty. METHODS: From September 2014 to December 2017, 18 patients(18 hips) with acetabular defect were reconstructed by porous tantalum Jumbo cup technology, including 6 males and 12 females;the age ranged from 54 to 76 years old with an average of(63.8±15.3) years. There were 6 cases of paprosky typeⅡA, 8 cases of typeⅡB, 2 cases of typeⅡC and 2 cases of type Ⅲ a. Harris score and visual analogue scale (VAS) were performed before and after operation. Imaging examination was performed to evaluate the position of hip rotation center and prosthesis, and to judge whether acetabular loosening, displacement and complications existed. RESULTS: All cases were followed up for 13 to 49 months, with an average of 20.6 months. Harris score increased from 54.6±4.7 to 86.5±3.2 one year after operation(P<0.01), and VAS score decreased from 6.8±0.7 to 0.8±0.6 one year after operation (P<0.01). The transverse coordinate of hip rotation center was (3.52±0.72) cm before operation and (3.47±0.54) cm after operation (P>0.05). The longitudinal coordinate of hip rotation center was improved from (3.02±0.84) cm before operation to (2.35±0.53) cm after operation (P<0.01). During the follow-up period, the Jumbo cup was well fixed without loosening and displacement, the acetabular cup had bone ingrowth in varying degrees, and no light transmission line and osteolysis around the acetabular cup were found. No complications such as infection and nerve injury occurred. CONCLUSION: The method of reconstructing acetabular bone defect with porous tantalum Jumbo cup is simple and easy, the early stability of acetabulum is good, and the short-term follow-up effect is good.

Intravenous regular insulin is an efficient and safe procedure for obtaining high-quality cardiac 18F-FDG PET images: an open-label, single-center, randomized controlled prospective trial.

BACKGROUND: An open-label, single-center, randomized controlled prospective trial was performed to assess the efficiency and safety of an insulin loading procedure to obtain high-quality cardiac 18F-FDG PET/CT images for patients with coronary artery disease (CAD). METHODS: Between November 22, 2018 and August 15, 2019, 60 patients with CAD scheduled for cardiac 18F-FDG PET/CT imaging in our department were randomly allocated in a 1:1 ratio to receive an insulin or standardized glucose loading procedure for cardiac 18F-FDG imaging. The primary outcome was the ratio of interpretable images (high-quality images defined as myocardium-to-liver ratios ≥ 1). The secondary outcome was the patient preparation time (time interval between administration of insulin/glucose and 18F-FDG injection). Hypoglycemia events were recorded. RESULTS: The ratio of interpretable cardiac PET images in the insulin loading group surpassed the glucose loading group (30/30 vs. 25/30, P = 0.026). Preparation time was 71±2 min shorter for the insulin loading group than for the glucose loading group (P < 0.01). Two and six hypoglycemia cases occurred in the insulin and glucose loading groups, respectively. CONCLUSION: The insulin loading protocol was a quicker, more efficient, and safer preparation for gaining high-quality cardiac 18F-FDG images.

Intravenous insulin injection supplemented with subsequent milk consumption is a safer formulation for cardiac viability 18F-FDG imaging.

BACKGROUND: The safety and efficacy of intravenous insulin injection coupled with subsequent milk consumption was evaluated for high-quality cardiac viability F-18-fluorodeoxyglucose (18F-FDG) images. METHODS AND RESULTS: A total of 328 patients with known/suspected coronary artery disease received intravenous insulin injection with or without subsequent milk consumption for cardiac 18F-FDG imaging. When blood glucose levels had decreased by ≥ 20%, 18F-FDG was injected. Patients were scored for hypoglycemic symptoms using a 10-point scale (discomfort: 0, none; 1 to 3, mild; 4 to 6, moderate; 7 to 9, severe). An insulin-related hypoglycemic event was defined as an increased symptomatic score following insulin injection. The number of hypoglycemic events was significantly lower in the milk consumption group than in the group that did not (24/164 vs. 51/164, P < .01). Maximal and averaged standardized uptake value of the left ventricular myocardium (MyoSUVmax and MyoSUVmean) were also measured. The milk and control groups had similar mean hypoglycemic symptom scores (4.2 ± 4.0 vs. 3.3 ± 3.1, respectively), MyoSUVmax, and MyoSUVmean (11.1 ± 4.8, 7.3 ± 3.2 vs. 11.4 ± 4.5, 7.4 ± 3.2, respectively). CONCLUSION: Intravenous insulin injection supplemented with subsequent milk consumption is a safer formulation for cardiac viability 18F-FDG imaging without impairing image quality.

Copper-Catalyzed Intermolecular Alkynylation and Allylation of Unactivated C(sp3)-H Bonds via Hydrogen Atom Transfer.

We describe Cu-catalyzed intermolecular alkynylation and allylation of unactivated C(sp3)-H bonds with singly occupied molecular orbital-philes (SOMO-philes) via hydrogen atom transfer (HAT). Employing N-fluoro-sulfonamide as a HAT reagent, a set of substituted alkene and alkyne compounds were synthesized in high yields with good regioselectivity and functional-group compatibility. Late-stage functionalization of natural products and drug molecules is also demonstrated.

Bubble-Liquid Membrane Method for Preparing Spherical Calcium Carbonate Nanoparticles.

In this work, we describe the principle and operation of a bubble-liquid membrane reactor, and use of the reactor to prepare spherical calcium carbonate nanoparticles. The products were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and laser particle size analysis. The effects of additives to control crystal morphology, coating agents, and the stirring speed of the bubble-liquid membrane reactor were investigated. Spherical calcium carbonate nanoparticles with uniform dispersion and no agglomeration were obtained when a disodium hydrogen phosphate/ethylenediaminetetraacetic acid disodium salt mixture (1:1 mass ratio) was used as the additive, oleic acid was used as the coating agent (1.5 wt%), and the stirring speed was 5000-6000 r/min. The results indicate that the bubble-liquid membrane reactor may be suitable for continuous industrial production of calcium carbonate nanoparticles.

Influence of Characteristics of Thermoplastic Polyurethane on Graphene-Thermoplastic Polyurethane Composite Film.

Graphene-thermoplastic polyurethane (G-TPU) composite films were fabricated by traditional blending method and tape casting process with commercial graphene sheets as functional fillers and TPU masterbatches of four different melting points as matrix, respectively. The effects of matrix on the distribution of graphene, the electrical conductivity, and infrared (IR) light thermal properties of the G-TPU composite films were investigated. The experimental results reveal that the characteristics of TPU has little influence on the electrical conductivity of the G-TPU composite films, although the four TPU solutions have different viscosities. However, under the same graphene mass content, the thermal conductivity of four G-TPU composite films with different melting points is significantly different. The four kinds of G-TPU composite films have obvious infrared (IR) thermal effect. There is little difference in the temperatures between the composite films prepared by TPU with melting a point of 100 °C, 120 °C, and 140 °C, respectively; however, when the content of graphene is less than 5 wt%, the temperature of the composite film prepared by TPU with a melting point of 163 °C is obviously lower than that of the other three composite films. The possible reason for this phenomenon is related to the structure of TPU.

Ghrelin attenuates ultraviolet B radiation-induced impairment in capacities of epidermal stem cells.

Persistent exposure to solar ultraviolet radiation (UVR) causes continuous damages to skin, including progressive impairment of epidermal stem cells (ESCs) capacities. Ghrelin is the only known endogenous orexigenic hormone, which has displayed its various pharmacological functions. In the current study, we found that the specific receptor of ghrelin, growth hormone secretagogue receptor (GHS-R), is expressed in ESCs. Interestingly, GHS-R expression is significantly upregulated in response to ultraviolet B (UVB) radiation. We also found that ghrelin treatment prevented UVB radiation-induced reduction in cell viability and the release of lactate dehydrogenase (LDH). Additionally, ghrelin reduced UVB radiation-induced generation of reactive oxygen species (ROS) and restored the intracellular level of reduced glutathione (GSH). UVB radiation significantly suppressed the expressions of integrin ß1 and Krt19, the two major ESC markers, which were restored by ghrelin. Notably, knockdown of GHS-R abolished the effects of ghrelin on the expressions of integrin ß1 and Krt19, suggesting the involvement of GHS-R. Also, we found that ghrelin treatment inhibited UVB radiation- induced reduction of Wnt1, Wnt3a, Myc, and cyclin D1 at both the mRNA levels and the protein levels. Taken together, our findings identify a novel function of ghrelin on maintaining the capacities of ESCs against UVB radiation.

Facile microencapsulation of olive oil in porous starch granules: Fabrication, characterization, and oxidative stability.

In this study, starch with porous structures derived from purple sweet potato was prepared and used as a food-grade polymer for the microencapsulation of olive oil. The optimal reaction conditions for preparing porous starch were determined to improve its adsorption capacity as effective microcapsule-wall materials. Olive oil was then impregnated in microspheres, and loading ratio was optimized by investigating the restrictive factors, including the mass ratio of olive oil to porous starch, as well as the embedding temperature and time. The presence of olive oil in the starch matrix was confirmed by SEM, FTIR, and TGA. Results demonstrated that the porous starch-based microencapsulation exhibit a stable olive oil loading ratio and a significant improvement in oxidative stability compared with free olive oil. The newly-proposed process used in this work was easy to scale up for developing a new and attractive method for oil protection in the food industry.

The role of macrophages in the differentiation process of ureteral polyps.

Objective To evaluate the role of macrophage infiltration in the differentiation process of ureteral polyps and cancers. Methods This retrospective immunohistochemical study analysed archival samples of pathologically-confirmed specimens of low- and high-grade ureteral cancer, ureteral papilloma and ureteral polyps. The samples were immunohistochemically stained for cluster of differentiation (CD)4, CD8, CD16, CD25, CD56 and CD68 using immunofluorescence in order to identify different T-lymphocyte populations and macrophages. Results A total of 70 specimens were included in the analysis: 21 specimens of ureteral cancer, 17 specimens of ureteral papilloma, and 32 specimens of ureteral polyps. The largest proportion of CD4+CD25+ regulatory T cells was observed in the low-grade ureteral cancer group and almost none were observed in ureteral papillomas. The largest proportion of CD8+ cytotoxic T-lymphocytes was observed in the ureteral polyps. The largest proportion of CD56+ natural killer cells was detected in the ureteral polyps, with very low levels observed in the other three groups. The largest proportion of CD16+CD68+ macrophages was observed in the high-grade ureteral cancer group, which was significantly higher than that observed in the ureteral papillomas. Conclusions This study revealed that CD16+CD68+ macrophages appear to participate in ureteral neoplastic transformation.

Enhanced growth suppression of TERT-positive tumor cells by oncolytic adenovirus armed with CCL20 and CD40L.

Conditionally replicating adenoviruses (CRAds) selectively replicate in cancer cells and induce cell lysis, which represents a potential platform for cancer immunotherapy. The chemokine CCL20 exerts antitumor activity via chemoattraction of immature dendritic cells (DCs) and lymphocytes. However, the activation and maturation status of DCs is a limiting factor in the DCs -based immunity response. CD40L induces the phenotypic maturation of DCs, mediates DCs cytokine secretion, and increases the expression of FasL, which mediates apoptosis. We constructed a CCL20/CD40L co-expression CRAds (Ad-CCL20-CD40L) based on the AdEasy system. Ad-CCL20-CD40L was constructed from three plasmids, pGTE-CD40L, pShuttle-CMV-CCL20 and AdEasy-1, and was homologously recombined and propagated in the Escherichia coli strain BJ5183 and the packaging cell line HEK-293, respectively. Ad-CCL20-CD40L selectively replicates in TERT-positive tumor cells because the pGTE-CD40L plasmid contains the telomerase reverse transcriptase promoter (TERTp). Our results showed that Ad-CCL20-CD40L induced oncolytic effects and tumor-specific cytotoxicity of cytotoxic T lymphocytes (CTLs) in vitro. This study suggests that Ad-CCL20-CD40L can induce the antitumor immune response and that this platform can be modified to generate novel CRAds with other transgenes.

The role of the Nrf2/Keap1 pathway in obesity and metabolic syndrome.

Nuclear factor erythroid 2 related factor 2 (Nrf2) is a key regulator of antioxidant signaling that may prevent the development of metabolic syndrome and related cardiovascular diseases. However, emerging evidence shows that lack of Nrf2 could ameliorate insulin resistance, adipogenesis and adipocyte differentiation. Consistent with this, overexpression of Nrf2 gene could also cause insulin resistance under certain conditions. Furthermore, an increasing number of studies indicate that redox balance can be a critical element that contributes to the contradictory effects of Nrf2 on insulin sensitivity and resistance. Reactive oxygen species can promote normal insulin-mediated signal transduction under physiological conditions but also induce insulin resistance under certain pathological conditions. Therefore, the contradictory effects of Nrf2 on insulin signaling pathways may be related to its regulation of redox homeostasis. This review attempts to summarize the latest developments in our understanding of the mechanisms of Nrf2-mediated signaling and its role in the modulation of metabolic homeostasis.

[Comparison of GIMMS and MODIS normalized vegetation index composite data for Qing-Hai-Tibet Plateau].

Consistent NDVI time series are basic and prerequisite in long-term monitoring of land surface properties. Advanced very high resolution radiometer (AVHRR) measurements provide the longest records of continuous global satellite measurements sensitive to live green vegetation, and moderate resolution imaging spectroradiometer (MODIS) is more recent typical with high spatial and temporal resolution. Understanding the relationship between the AVHRR-derived NDVI and MODIS NDVI is critical to continued long-term monitoring of ecological resources. NDVI time series acquired by the global inventory modeling and mapping studies (GIMMS) and Terra MODIS were compared over the same time periods from 2000 to 2006 at four scales of Qinghai-Tibet Plateau (whole region, sub-region, biome and pixel) to assess the level of agreement in terms of absolute values and dynamic change by independently assessing the performance of GIMMS and MODIS NDVI and using 495 Landsat samples of 20 km x20 km covering major land cover type. High correlations existed between the two datasets at the four scales, indicating their mostly equal capability of capturing seasonal and monthly phenological variations (mostly at 0. 001 significance level). Simi- larities of the two datasets differed significantly among different vegetation types. The relative low correlation coefficients and large difference of NDVI value between the two datasets were found among dense vegetation types including broadleaf forest and needleleaf forest, yet the correlations were strong and the deviations were small in more homogeneous vegetation types, such as meadow, steppe and crop. 82% of study area was characterized by strong consistency between GIMMS and MODIS NDVI at pixel scale. In the Landsat NDVI vs. GIMMS and MODIS NDVI comparison of absolute values, the MODIS NDVI performed slightly better than GIMMS NDVI, whereas in the comparison of temporal change values, the GIMMS data set performed best. Similar with comparison results of GIMMS and MODIS NDVI, the consistency across the three datasets was clearly different among various vegetation types. In dynamic changes, differences between Landsat and MODIS NDVI were smaller than Landsat NDVI vs. GIMMS NDVI for forest, but Landsat and GIMMS NDVI agreed better for grass and crop. The results suggested that spatial patterns and dynamic trends of GIMMS NDVI were found to be in overall acceptable agreement with MODIS NDVI. It might be feasible to successfully integrate historical GIMMS and more recent MODIS NDVI to provide continuity of NDVI products. The accuracy of merging AVHRR historical data recorded with more modern MODIS NDVI data strongly depends on vegetation type, season and phenological period, and spatial scale. The integration of the two datasets for needleleaf forest, broadleaf forest, and for all vegetation types in the phenological transition periods in spring and autumn should be treated with caution.

[Fluorescence enhancement effect of silver nanoparticles with different surface modifiers and sizes].

Silver nanoparticles were prepared by chemical method using citricacid trisodiumsalt (Ag-CTS) and polyvinylpyrrolidone (Ag-PVP) as surface modifiers, respectively. When Ag-CTS or Ag-PVP nanoparticles were added into methyl orange (MO) solution, the enhanced-fluorescence of S1-->S0 and quenched-fluorescence of S2-->S0 were simultaneously observed. However, for the solution containing Ag-PVP, the red-shift of fluorescence peak of S1-->S0 was observed and the extents of the enhanced-fluorescence of S1-->S0 and quenched-fluorescence of S2-->S) are higher than those of the solution containing Ag-CTS. With the increase in reaction time the fluorescence intensity of S1-->S0 increased gradually in the solution containing Ag-CTS nanoparticles and no change was observed in the solution containing Ag-PVP nanoparticles. The lower the MO concentration, the higher the fluorescence intensity ratio of S1-->S0. The results indicated that the silver nanoparticles with different surface modifiers affect the metal-enhanced fluorescence by impacting the distance between the methyl orange and silver nanoparticles. The size of silver nanoparticles affects the metal-enhanced fluorescence due to the difference in the surface plasma resonance properties.

[Photoluminescence of silver nanoparticles].

In the present paper, the photoluminescence of silver nanoparticles with different size and surface modifier was studied. The results show that the strong emission peak at 362 nm and the two weak emission peaks at 592 and 725 nm respectively were observed by excitation at different wavelengths. With increasing excitation wavelength, the intensity of emission peak decreased and the emission peak at 362 nm red-shifted. Otherwise, the photoluminescence of silver nanoparticles was sensitive to the excitation light of 210 nm. The emission peak has little relation with the surface modification and particle size of silver nanoparticles, just as the particle size decreased, the intensity of peak decreased. The intensity of emission peak decreased with the slit width decreased. The emission peaks gradually gathered together and merged into single peak at 426 nm, and the intensity first increased and then decreased. The mechanism of photoluminescence of silver nanoparticles was discussed by absorption--reemission of photoelectrons and interface energy hybridization.

[Effect of pH of methyl orange solution on the fluorescence enhancement effect of silver nanoparticles].

In the present paper, the effect of pH value of methyl orange solution on the fluorescence enhancement effect of silver nanoparticles was studied. When pH 1.5 and 2.1 the absorption spectra had little change with added silver colloid. When pH 3.1 a blue shift of 26 nm and a decrease in the intensity of the absorption peak were observed. When the values of pH are in the range of 3.8 - 8.2 a blue shift of the absorption peak and a 426 - 456 nm broad absorption band were observed. When silver colloids were added into methyl orange solutions with different pH values the fluorescence intensity of S2 --> S0 electronic transition decreased and was little impacted by pH value; while the fluorescence intensity of S1 --> S0 electronic transition was enhanced and was impacted by pH value. The largest and smallest fluorescence enhancement ratios were observed at pH 2.1 and 4. 8, respectively. The results indicated that the reasons of effect of pH of methyl orange solution on the fluorescence enhancement of silver colloid depend on methyl orange structure, molecular adsorption mode, media and so on, especially the distance between molecule and silver nanoparticle.

[Effects of KCl on fluorescence of [Ru(bpy)3]2+ solution containing silver nanoparticles].

In the present paper, the authors studied the effects of KCl on the fluorescence of [Ru(bpy)3]2+ solution containing silver nanoparticles by UV-Vis absorption spectra and fluorescence spectra. The results indicated that the stronger action between KCl and silver nanoparticles led to the vanishing of chain-like net structure formed between [Ru(bpy)3]2+ and silver nanoparticles and the formation of large particles and aggregates in the solution. Meanwhile, a new band at longer wavelength region appeared and the peak at long wavelength was red-shifted and broadened with the increase of KCl. With the increase in KCl content, the fluorescence decreases first and then increases till a constant value. The authors discussed the mechanism of the effects KCl on the fluorescence of [Ru(bpy)3]2+ solution containing silver nanoparticles in terms of interaction and energy transfer.