Resonance light scattering technique for sensitive detection of heparin using plasmonic Cu2-xSe nanoparticles.

Heparin (Hep) is a mucopolysaccharide sulfate anticoagulant drug widely used in clinic and thus the quantification of Hep concentration is of great significance. In this work, a simple resonance light scattering (RLS) method for the determination of Hep concentration using plasmonic copper selenide nanoparticles (Cu2-xSe NPs) was developed. The positively-charged Cu2-xSe NPs capped by cetyltrimethyl ammonium bromide (CTAB) were aggregated by negatively-charged Hep, consequently inducing a significant enhancement in the RLS signals of plasmonic Cu2-xSe NPs. Under the optimal reaction conditions, the increased RLS intensity is linearly correlated with the concentrations of Hep in the range of 0.01-0.60 µg mL-1 (R2 = 0.999), with a low detection limit (LOD) of 4.0 ng mL-1 (3σ). This method offered a simple, sensitive and selective strategy for determining Hep, which can be further successfully applied to quantify Hep in the heparin sodium injection.

Analysis of phytochemical contributors to antioxidant capacity of the peel of Chinese mandarin and orange varieties.

The phytochemicals in the peel of six oranges and ten mandarins including seven wild varieties and three cultivars were systematically characterised using UHPLC-Q-TOF-MS, and the correlation analysis was performed between phytochemicals and antioxidant capacity in order to investigate the phytochemical contributors to antioxidant capacity. The gradient elution was completed within 16 min and 92 compounds were undoubtedly or tentatively identified. Furthermore, the antioxidant capacities were determined using ABTS, DPPH and FRAP methods. The number of compounds, their contents and the antioxidant capacities were sequenced in the same order of the wild mandarins > cultivated mandarins > oranges. The correlation analysis that showed five compounds were significantly correlated with the antioxidant capacity and can act as main contributors to the citrus varieties with high antioxidant capacities. This study is systematic for the metabolites identification of mandarins and oranges and provides valuable information for effective utilisation of citrus peel and their bioactive compounds.

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.

Plasmonic Cu2- xS ySe1- y Nanoparticles Catalyzed Click Chemistry Reaction for SERS Immunoassay of Cancer Biomarker.

Nature enzyme-based immunoassays have been widely used in fundamental scientific research and clinical diagnosis. However, the limitations of natural enzyme, such as the low physical/chemical stability or susceptibility to protein denaturation, greatly restrained its applications. In this article, we reported a new enzyme-free SERS immunoassay by utilizing plasmonic Cu2- xS ySe1- y nanoparticles (NPs) as nanocatalyst to catalyze the click chemistry between the azido and alkynyl substrate which is used as the SERS signal reporter. The unique vibration of C≡C of alkynyl in the Raman-silent region (1800-2800 cm-1) is not overlapped with the signals of the other conventional Raman reporters or endogenous biological species, and thus it can make sure the enzyme-free SERS immunoassay has high selectivity and sensitivity. As a proof of concept, prostate-specific antigen (PSA), a biomarker of prostate cancer in blood, has been detected. The SERS immunoassay shows good analytical performance for PSA in the range of 3-120 ng mL-1, and it has been successfully applied to detect PSA in the serum samples of prostate cancer patients, proving that the proposed enzyme-free SERS immunoassay has great potential in the clinical diagnosis of cancer.

Efficient analysis of phytochemical constituents in the peel of Chinese wild citrus Mangshanju (Citrus reticulata Blanco) by ultra high performance liquid chromatography-quadrupole time-of-flight-mass spectrometry.

An efficient ultra high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method was developed for separation and profiling of phytochemical constituents of Chinese wild mandarin Mangshanju (Citrus reticulata Blanco). All constituents were well separated within 16 min. Based on retention times, accurate mass, MSE fragments, and/or reference standards as well as databases, a total of 81 compounds were unambiguously identified or tentatively assigned including flavonoid glycosides, acylated flavonoid glycosides, flavones, polymethoxylated flavonoids, and limonoids as well as four other compounds. Among them, 22 polymethoxylated flavones and ten polymethoxylated flavanones/chalcones were identified in Mangshanju, more types than other citrus reported before. A basic procedure for identifying flavonoid-O-glycosides and the aglycones including polymethoxylated flavonoids was proposed. In addition, this method was successfully used to analyze another four mandarin germplasms, Cenxi suan ju, Xipi gousi gan, Nanfeng miju, and Or, showing that Mangshanju contained two characteristic compounds distinct from the other four citrus species. This study systematically profiled phytochemical constituents of Mangshanju, which was helpful for further utilization of Mangshanju owing to its abundant bioactive compounds.

Fast Separation and Sensitive Quantitation of Polymethoxylated Flavonoids in the Peels of Citrus Using UPLC-Q-TOF-MS.

A rapid, sensitive, and efficient ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) method has been developed to analyze polymethoxylated flavonoids (PMFs) in 14 Citrus peels, including 7 Citrus reticulata (C. reticulata) and 7 Citrus sinensis (C. sinensis). In this study, fast separation can be achieved within 12 min and 42 PMFs have been identified including 33 flavones and 9 flavanones. Most C. reticulata were shown to contain more than 20 PMFs, except Guangxihongpisuanju (GX) containing only 12 PMFs, while most C. sinensis contained fewer than 20 PMFs, except Edangan (EG) containing as many as 32 PMFs. To our knowledge, there are few reports about the quantitation of PMFs using the MS response. Here, a MS quantitative method was established and systematically validated in linearity, precision, and recovery. The linearity was from 1.25 ng/mL to 1.0 µg/mL with the limit of detection (LOD) as low as 75 pg/mL and the limit of quantitation (LOQ) as low as 0.25 ng/mL. Up to 13 PMFs, more types than ever before, were undoubtedly identified and quantitated according to the PMF standards. The results showed that the contents of PMFs in the C. reticulata were generally higher than those in the C. sinensis. This study is systematic for analyzing PMFs and is of great significance because it can provide guidance on utilization of both PMFs and citrus germplasm resources in the future.

[Comparison of two types of digestive tract reconstruction after total gastrectomy in patients with gastric carcinoma].

OBJECTIVE: To evaluate the influence of two different types of digestive tract reconstruction on the life quality, nutritional status and tolerance to adjuvant chemotherapy after total gastrectomy in patients with gastric carcinoma. METHODS: The clinical data of a total of 107 patients treated in our department from January 2005 to december 2008 were analyzed retrospectively. Among them, 49 patients underwent digestive tract reconstruction with functional jejunal interposition (FJI group) and 58 patients underwent Roux en-Y jejunal P-type anastomosis (PR group) after total gastrectomy. 79 of 107 (73.8%) patients received postoperative adjuvant chemotherapy with XELOX regimen. The digestive complications and tolerance to chemotherapy were assessed respectively. RESULTS: Neither severe complications nor surgery-related or chemotherapy-related death were observed among the 107 patients. There were statistical differences in the incidence rate of emaciation, dumping syndrome and retention syndrome between the FJI and PR groups (P < 0.05), but no significant statistical difference in incidence rate of reflux esophagitis (P > 0.05). 28 of 40 (70.0%) patients in the FJI group completed all six cycles of chemotherapy, while 12 (30.0%) patients interrupted the treatment due to chemotherapy-related toxicity. 39 patients in the PR group received chemotherapy, 19 (48.7%) of them completed 6 cycles of chemotherapy but 20 (51.3%) patients interrupted. There was a significant difference in the incidence rate of grade III/IV chemotherapeutic toxicity and completion rate of chemotherapy (P < 0.05). CONCLUSIONS: Both functional jejunal interposition and Roux-Y operation are reasonable and safe procedures of digestive tract reconstruction. The incidence rates of emaciation, dumping syndrome and retention syndrome are lower in the patients with FJI, showing a better tolerance to adjuvant chemotherapy than Roux en-Y jejunal p type anastomosis.

No survival benefit from postoperative adjuvant chemotherapy after D2 radical resection for the patients with stage II gastric cancer.

OBJECTIVE: To evaluate the effect of 2 regimens of postoperative combination chemotherapies on the prognosis of early stage gastric cancer patients. METHODS: A total of 268 patients with stage II gastric cancer underwent D2 resection in our Cancer Center between January 1990 and December 2006 were recruited. Among them, 34 patients received the FAM regimen (5-fluorouracil [5-FU] 600 mg/m(2) intravenous [IV] drip on days 1, 8, 29, and 36; doxorubicin 30 mg/m(2) IV bolus injection on days 1 and 29; and mitomycin-C 10 mg/m(2) IV bolus injection on day 1; repeated every 8 weeks) and 81 patients received the FOLFOX regimen (oxaliplatin 100 mg/m(2) IV drip on days 1 and 15; leucovorin 400 mg/m(2) IV drip on days 1 and 15; 5-FU 400 mg/m(2) IV bolus injection; 5-FU 2.4/3.0 mg/m(2) continuous IV infusion for 48 hours on day 1, 2, 15, and 16; repeated every 4 weeks for at least 4 cycles). Patients were followed-up until December 2008. The Kaplan-Meier method was used to compare survival rates between treatment groups. RESULTS: The 1-, 3-, 5-, and 10-year survival rates for the patients who received postoperative chemotherapy versus the patients who underwent surgery only were 98%, 84%, 58%, 18% versus 96%, 78%, 59%, 22%, respectively (P > 0.05). Furthermore, the survival rates for patients who received the FAM and FOLFOX regimens were not significantly different (P > 0.05). CONCLUSIONS: Postoperative adjuvant chemotherapy did not produce survival benefits for the patients with stage II gastric cancer. Randomized controlled clinical trials are demanded to confirm the finding from this study.