Search

ReO4− is slowly reduced to ReO42− and Re(iv) species by hydrazine, and ReO2·nH2O catalyzes hydrazine decomposition.

Carbon dots (C-dots) are attractive for their low cost, excellent optical properties, and low toxicity, but most C-dots are limited by their UV absorbance, especially for photodynamic therapy (PDT) applications. Developing rational and simple strategies to obtain C-dots with longer excitation/emission wavelengths remains a challenge. Previous work showed that C-dots can produce a high yield of reactive oxygen species (ROS) upon UV light illumination. We herein show that the produced ROS can lead to further oxidation and growth of C-dots, leading to visible light absorption (400 nm–650 nm) and extend fluorescence emission from blue to green. In addition, the light-treated C-dots showed boosted peroxidase and oxidase mimicking activity than the initial C-dots in the absence of light. In the presence of visible light, the catalytic efficiency of the light-treated C-dots is 11-fold much higher than the pristine C-dots. The light-treated C-dots can be used as a PDT agent due to the extended excitation and visible photo-oxidative activity, simultaneously providing a highly efficient cancer therapy. This study provides a simple way to modify C-dots leading to novel properties.

Inspired by the headspace sampling (HS) device, a versatile high-throughput photochemical reactor with twenty vessels serving as both the photochemical vapor generator and the HS device was developed for the rapid and sensitive determination of mercury, nickel, and selenium by coupling photochemical vapor generation (PVG) to atomic fluorescence spectrometry (AFS) or point discharge optical emission spectrometry (μPD-OES). The photochemical reactor utilized a specially designed annular UV lamp around which the vessels containing sample solution were automatically rotated and irradiated to yield gaseous analyte species. Subsequently, the species escaped into the headspace of vessels prior to introduction to the atomic spectrometer. Compared with the conventional flow injection (FI) or continuous flow (CF) PVG, the developed PVG-HS method possesses several unique advantages including high throughput (260 pcs h

Despite increased interest in microplasma-induced vapor generation (μPIVG) over the past several years, applications in real sample analyses remain limited due to their relatively low vapor generation efficiency and ambiguous mechanism. In this work, a novel method using methanol for significantly enhancing the liquid electrode discharge μPIVG efficiency was developed for the simultaneous and sensitive determination of Hg, Cd, and Zn by atomic fluorescence spectrometry (AFS). It is worth noting that the possible enhancement mechanism was investigated via the characterizations of volatile products by AFS, microplasma optical emission spectrometry, online gas chromatography, and gas chromatography-mass spectrometry, which involved the reductive species such as electrons, hydrogen radicals (·H), methyl radicals (·CH3), and other intermediates in the argon plasma adding methanol. Under the optimized conditions, the limits of detection of 0.007, 0.05, and 0.5 μg L-1 were obtained for Hg, Cd, and Zn, respectively, with relative standard deviations of 3.1, 3.7, and 5.2% for these elements, respectively. Vapor generation efficiencies of 90, 83, and 55% were achieved for Hg, Cd, and Zn, respectively, and improved 2.7-, 4.8-, and 7.9-fold, respectively, compared to those obtained in the absence of methanol. The accuracy and practicability of the proposed method were validated by the determination of Hg, Cd, and Zn in a certified reference material (CRM, Lobster hepatopancreas, TORT-3) and crayfish samples collected from three different provinces of China.

Background Thus far, the association of tumor size with prognosis in colon cancer has not been considered and has remained unclear. This study, therefore, aimed to investigate the association between tumor size as a continuous variable and prognosis in colon cancer using Cox models with restricted cubic splines. Methods Using the Surveillance, Epidemiology, and End Results database, we selected 128,369 patients with colon cancer who underwent surgery. Overall survival and colon cancer-specific survival were separately analyzed, and tumor size was separately evaluated as a continuous variable and a categorical variable. To investigate the relationship after adjusting for covariates, we used the proportional hazards models. The restricted cubic splines model was used to determine the presence of nonlinear or linear association and flexibly visualize the association. Results The adjusted covariate model showed that the hazard ratio of colon cancer rapidly increased with a tumor size of 4 cm and slowly increased with a tumor size larger than 4 cm. When tumor size was analyzed as a categorical variable, the multivariable-adjusted model demonstrated a nearly linear relationship between tumor size and hazard ratio regardless of overall survival or cancer-specific survival, and the hazard ratio of group 5 (4.1–5 cm) was nearly a turning point. Subgroup analysis with respect to lymph node metastasis showed that the relationship between tumor size and prognosis in colon cancer was evident in lymph node metastasis. Conclusion There was a strong negative relationship between tumor size and prognosis in colon cancer. However, when tumor size was less than 4 cm, the relationship between tumor size and prognosis was steep compared with that when tumor size was larger than 4 cm, especially in lymph node metastasis.

DNAzymes have emerged as a powerful class of sensors for metal ions due to their high selectivity over a wide range of metal ions, allowing for on-site and real-time detection. Despite much progress made in this area, detecting and quantifying tightly bound metal ions, such as those in the blood serum, remain a challenge because the DNAzyme sensors reported so far can detect only mobile metal ions that are accessible to bind the DNAzymes. To overcome this major limitation, we report the use of a photocaged chelator, XDPAdeCage to extract the Zn2+ from the blood serum and then release the chelated Zn2+ into a buffer using 365 nm light for quantification by an 8-17 DNAzyme sensor. Protocols to chelate, uncage, extract, and detect metal ions in the serum have been developed and optimized. Because DNAzyme sensors for other metal ions have already been reported and more DNAzyme sensors can be obtained using in vitro selection, the method reported in this work will significantly expand the applications of the DNAzyme sensors from sensing metal ions that are not only free but also bound to other biomolecules in biological and environmental samples.

AIMS: We aimed to understand the association between stent length and clinical outcomes after percutaneous coronary intervention (PCI) using newer-generation drug-eluting stents (DES). METHODS AND RESULTS: We analysed 9,217 patients who underwent stenting for a single lesion from the GRAND-DES registry, a patient-level pooled registry including five Korean multicentre DES registries. The median follow-up duration was 730 days (interquartile range 708 to 752 days). A total of 8,035 patients were classified into the short stenting group (≤40 mm), and 1,182 into the long stenting group (>40 mm). The primary endpoint was target lesion failure (TLF). Long stenting (>40 mm) was significantly associated with higher TLF (IPTW adjusted HR 1.88, 95% CI: 1.67-2.13; p

Purpose Tumors with lymphovascular invasion (LVI) are thought to be associated with lymph node metastasis and to lead to a worse prognosis. However, the effect of LVI on the prognosis of adenocarcinoma of esophagogastric junction (AEG) is still unclear. Patients and methods We retrospectively analyzed 224 consecutive patients with non-metastatic AEG who underwent radical surgery in our hospital from 2004 to 2018. Inverse probability weighting (IPW) analysis was used to eliminate the selection bias. IPW-adjusted Kaplan-Meier curves and Cox proportional hazards models were used to compare disease-specific survival (DSS) and overall survival (OS) between patients with and without LVI. Results A total of 224 patients with non-metastatic AEG who underwent radical resection were included in the study and 96 (42.9%) patients developed LVI. Survival analysis showed that LVI were associated with worse DSS (hazard ratio (HR) = 3.12; 95% CI: 1.93-5.03) and worse OS (HR = 2.33; 95% CI: 1.61-3.38). The results were consistent across subgroups stratified by pathologic N stage. Subgroup analysis demonstrated that Siewert type III (HR= 3.20, 95% CI: 1.45-7.06) was associated with worse DSS, but not Siewert type I/II (HR= 1.46, 95% CI: 0.94-2.31, P-interaction=0.047). Conclusion LVI are associated with worse prognosis in AEG. LVI had a worse effect on DSS in Siewert type III AEG than Siewert type I/II AEG.

Graphene oxide (GO)-functionalized pencil lead fiber was prepared for the first time by in situ oxidation and exfoliation of graphite contained in pencil lead fiber to porous graphene oxide structure via a one-step solvent-free dielectric barrier discharge (DBD) microplasma treatment. This new fiber was demonstrated as a highly efficient and low-cost solid-phase microextraction (SPME) fiber for the determination of toxic metal ions. The fiber extraction performance was evaluated by using cadmium as a model analyte in a direct immersing SPME mode. Unlike most commercially available and other lab-built fibers, the preparation of the graphene oxidized pencil lead fiber is environmentally friendly, low cost, and non-toxic without using any organic solvents. The fiber is robust due to its coating-free configuration. Furthermore, high extraction efficiency and high sensitivity for cadmium can be obtained due to the abundant oxygen-containing functional groups on the surface of the novel fiber. After extraction, the cadmium adsorbed on the fiber was desorbed to 150-μL solution. Graphite furnace atomic absorption spectrometry (GF-AAS) with low sample consumption was used to determine cadmium. The calibration curve for cadmium ions was linear in a range 0.04–0.26 μg L−1 with a detection limit of 0.005 μg L−1. A relative standard deviation (RSD, n = 5) of 2.1% was obtained at 0.1 μg L−1 of cadmium. The sensitivity enhancement factor (EF) value of the proposed SPME method was 25. The SPME fiber was successfully applied to determine cadmium in tap water, river water, and pond water with spike recoveries ranging from 94 to 105%. Pipe network water samples were also analyzed to evaluate the cadmium release to drinking water due to the corrosion of tubes.

In this work, the reduction of mercury ions (Hg2+) to elemental mercury (Hg0) was easily achieved using highly reductive carbon dots (r-CDs), which synthesized from sucrose by a simple and cost-effective method. After a careful mechanistic study, the reduction was probably accomplished with the large numbers of electrons contained in r-CDs rather than the oxidation of its functional groups. Additionally, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the r-CDs were nontoxic to wildlife and human beings. Consequently, the r-CDs were used as an alternative to toxic reductants (SnCl2 or NaBH4) for the sensitive and in situ determination of mercury by cold vapor generation (CVG) coupled to a miniature point discharge optical emission spectrometer (μPD-OES). Limit of detection of 0.05 μg/L was obtained for Hg2+, with relative standard deviation (RSD) less than 5.4% at a concentration of 5 μg/L. The accuracy of r-CDs induced CVG-μPD-OES was validated by the determination of mercury in a certified reference material (DOLT-5, dogfish liver) and five natural water samples collected from different rivers and lakes in Chengdu City. Since r-CDs are nontoxic and prepared from abundant and inexpensive sucrose, the r-CDs induced CVG-μPD-OES retains the great potential for the inexpensive and environmentally friendly field analysis of mercury in natural water. The accuracy of the proposed method was validated by the analysis of a certified reference material and several water samples with satisfactory results.

Purpose Gastrointestinal stromal tumors (GISTs) are commonly known to be derived from the gastrointestinal (GI) tract, but recently there have been more and more literature describing lesions with similar pathological and immunohistochemical resembling GISTs but located outside the GI tract, and they have been termed as extra-GISTs (eGISTs). However, due to the rare incidence of eGISTs, its association with survival outcomes is poorly understood, especially in the Chinese population. Here, we aimed to identify the risk factors of eGISTs and to assess their association with overall survival (OS) and disease-free survival (DFS). Patients and methods Data of pathologically confirmed eGISTs cases, without radiological and perioperative evidence of other primary lesions, and with no microscopically identified adhesion between the tumor and the gastrointestinal serosa, which were surgically treated between January 2006 and September 2017 were retrieved from the database of four high-volume hospitals. Immunohistochemical and genetic testing were performed on the postoperative lesions and were staged using the National Institutes of Health (NIH) criteria. Results A total of 55 cases were retrieved. eGISTs were identified from the retroperitoneum (36.4%), mesocolon (25.5%), small bowel mesentery (12.7%), abdominopelvic cavity (12.7%), lesser omental sac (5.5%), ovary (3.6%), pancreatic capsule (1.8%), or urinary bladder (1.8%). Based on the NIH risk classification, majority of the lesion were classified as high risk (85.5%). KIT 11 was the most common mutation site (76.5%) and 25.0% of the cases were wild-type eGISTs. Multivariate analyses showed that tumor location and size were independent factors affecting prognoses. Patients with tumors in the retroperitoneum had significantly poorer OS and DFS as compared to those in the non-retroperitoneum (HR [95% CI] for OS and DFS: 2.546 [1.023-6.337] [P = 0.037] and 2.475 [0.975-6.273] [P = 0.049], respectively). Similar findings were found for tumors of size >15 cm, compared to ≤15 cm (HR [95% CI] for OS and DFS: 5.350 [2.022-14.156] [P Conclusion eGISTs were predominantly found from the retroperitoneum and mostly classified as high risk. Those located in the retroperitoneum and of size >15 cm had the poorer OS and DFS as compared to those in the non-retroperitoneum and of size

An extremely simple, cost-effective, and one-step method was developed for the preparation of solid-phase microextraction (SPME) fibers via the in situ synthesis of carbonaceous nanoparticles on the surface of stainless steel fiber from a candle flame. The prepared SPME fiber provided excellent adsorption capability toward Hg

Although platinum-based materials are regarded as the state-of-the-art electro-catalysts for hydrogen evolution reaction (HER), high cost and quantity scarcity hamper their scale-up utilization in industrial deployment. Herein, a one-step strategy was developed to synthesize multi-walled carbon nanotubes and reduced graphene oxide supported Pt nanoparticle hydrogel (PtNP/rGO-MWCNT), in which only ascorbic acid was used as the reductant for one-pot reduction of both GO and chloroplatinic acid. The hydrogel can be directly used as a flexible binder-free catalytic electrode to achieve high performance of HER. Compared to conventional strategies, the current strategy not only significantly reduces the Pt loading to 3.48 wt%, simplifies the synthesis process, but also eliminates the use of any polymer binders, thus decreasing the series resistance and improving catalytic activity. An overpotential of only 11 mV was achieved on as-prepared PtNP/rGO-MWCNT to drive a geometrical current density of 10 mA/cm2 in 0.5 mol/L H2SO4, with its catalytic activity being kept over 15 h. In acidic medium, the HER activity of the PtNP/rGO-MWCNT catalyst exceeds most of the reported Pt-based electro-catalysts and is 3-fold higher than that obtained on commercial Pt/C electrode.

Recently, the use of atomic spectrometry (AS) for biochemical analysis has attracted considerable attention due to its high sensitivity, selectivity and anti-interference ability. In this work, we conducted a detailed study on a phenomenon of thiol inhibition of mercury (Hg2+) cold vapor generation (CVG) and found L-cysteine (L-Cys), glutathione (GSH), dithiothreitol, N-Acetyl-L-cysteine, 3-mercaptopropionic acid, β-mercaptoethanol, and NaI can inhibit the CVG of Hg2+, while EDTA has no inhibitory effect. Furthermore, changing the content of –SH can effectively adjust the CVG atomic fluorescence spectrometer (CVG-AFS) signal of Hg2+. As as a consequence, an AS-based homogeneous bioassay was constructed by adjusting the oxidation ratio and production quantity of –SH in the system. The quantitative analysis of the system was demonstrated by using AFS as a representative detector. Hydrogen peroxide (H2O2) and glucose were used as representative analytes for the validation of Hg2+ atomic fluorescence signal turn-off strategy, and butyrylcholinesterase (BChE) as well as parathion (organophosphorus pesticides, OPs) as utilized as representative targets for the signal turn-on strategy. Under optimal experimental conditions, the homogeneous CVG-AFS sensor can be successfully used to detect 3 μM H2O2, 30 μM glucose, 0.25 U/L BChE, and 0.4 μg/mL parathion. In addition, the detection results of glucose and BChE in human serum samples agreed well with those obtained by using glucometer and kit, showing the promising potential of this method for practical applications. Therefore, this work provides a perspective for the construction of AS-based homogeneous bioassays and shows great potential for the detection of biomarkers.

Importance. Extragastrointestinal stromal tumor (EGIST) is a rare tumor, and its diagnosis and treatment strategy lack clinical guideline and relative literature evidence. In clinical practice, EGIST only misuses the pattern of GIST of diagnosis and treatment. The study hopes to find evidence of the treatment pattern for EGIST. Objective. This study aimed to compare the tumor characteristics and long-term outcomes between EGIST and GIST. The confounding function was applied to improve the result credibility in the case of small sample size. Design, Setting, and Participants. This cohort study enrolled 55 patients with EGIST who underwent surgery and were selected from four high-volume hospitals in China and 221 GIST patients who were collected from one of the four hospitals between January 2006 and September 2017. We used propensity score matching (PSM) and subgroup analysis to compare EGIST with GIST in terms of prognosis. The confounding function was used for sensitivity analysis to reduce unmeasured confounding. Results. We matched 43 patients in each of the GIST and EGIST groups by PSM. We compared EGIST data with GIST data to explore the prognostic factors between them. In the multivariate Cox regression model, tumor location of EGIST was negatively correlated with overall survival (after PSM: HR, 4.32; 95% CI, 1.22–15.26) or disease-free survival (after PSM: HR, 9.79; 95% CI, 2.22–43.31), which was also intuitively shown in the Kaplan–Meier survival curves (all P values < 0.05). In the subgroup analysis, EGIST with high risk factors had a worse prognosis than GIST. In unmeasured confounding analysis, the overall curve tends to show all combinations of c(0) of c(1) up to 2.0, none of which would bring the corrected relative risk to 1 for OS and DFS. Conclusions and Relevance. EGIST was associated with worse prognosis compared with GIST patients, particularly in EGIST patients with high risk factors, while there was a similar prognosis without those high risk factors.

Background To evaluate the prognostic impact of the advanced lung cancer index (ALI) in patients with the adenocarcinoma of esophagogastric junction (AEG) after radical resection. Methods The data of patients with AEG after radical resection at Guangdong Provincial People’s Hospital from January 2008 to December 2018 were retrieved. The cutoff value of ALI was determined and the prognostic impact of clinicopathological factors and ALI were analyzed. A nomogram based on the independent prognostic factors for overall survival was then built. Results A total of 147 patients were eligible and based on a cutoff of ALI 43.1, 90 (61.2%) and 57 (38.8%) patients were classified in a low- (ALI༜43.1) and high-ALI (ALI༞43.1) group. Multivariate Cox proportional hazard analysis showed that low-ALI was associated with poor overall survival (OS) (p༜0.001, HR 2.541, 95%CI 1.408-4.410) and disease-free survival (DFS) (p=0.021, HR 1.789, 95%CI 1.020-2.674). In subgroup analysis, low-ALI was independent predictor for OS (p=0.001, HR 2.628, 95%CI 1.467-4.707) in stage III/IVA AEG patients. A nomogram for OS estimation was constructed and the C-index was 0.699 (95%CI 0.636-0.762) and the calibration plots showed satisfactory consistency between actual observation and nomogram-predicted OS probabilities. Further, satisfactory predictive accuracy for 1-, 2-, and 3-year OS rates with an area under the curve of 0.736, 0.712 and 0.697, respectively, was observed. Conclusions ALI was an independent prognostic factor for AEG patients after radical resection, and demonstrated promising ability for risk stratification of AEG, especially in advanced-stage disease.

Due to the large size and high energy consumption of instruments, field elemental speciation analysis is still challenging so far. In this work, a portable and compact system device (230 mm length × 38 mm width × 84 mm height) was fabricated by using three-dimensional (3D) printing technology for the field speciation analyses of mercury and inorganic selenium. The device comprises a cold vapor generator, photochemical vapor generator, and miniaturized point discharge optical emission spectrometer (μPD-OES). For mercury, inorganic mercury (IHg) was selectively reduced to Hg0 by cold vapor generation, whereas the reductions of both IHg and methylmercury (MeHg) were obtained by photochemical vapor generation (PVG) in the presence of formic acid. For selenium, Se(IV) and total inorganic selenium were converted to their volatile species by PVG in the presence and the absence of nano-TiO2, respectively. The generated volatile species were consequently detected by μPD-OES. Limits of detection of MeHg, IHg, Se(IV), and Se(VI) were 0.1, 0.1, 5.2, and 3.5 μg L-1, respectively. Precision expressed as the relative standard deviations (n = 11) were better than 4.5%. The accuracy and practicality of the proposed method were evaluated by the analyses of Certified Reference Materials (DORM-4, DOLT-5, and GBW(E)080395) and several environmental water samples with satisfactory recoveries (95-103%). This work confirms that 3D printing has great potential to fabricate a simple, miniaturized, easy-to-operate, and low gas and power consuming atomic spectrometer for field elemental speciation analysis.

Catalytic cascades have drawn much attention by avoiding the isolation of intermediates and due to high atom economy. Yet, developing an efficient, one-pot biocatalytic cascade remains challenging. Combined with the selectivity of biological enzymes and tunable activity of nanozymes, we herein demonstrate an effective bio-nanozyme cascade formed by glucose oxidase (GOx) and in situ-generated nanoceria. The prepared H2O2-nanoceria complex shows strong oxidative activity for common chromogenic substrates under physiological conditions, which are the optimal reaction conditions for most biological enzymes. Interestingly, GOx not only provides H2O2 for the second step reaction but also simultaneously leads to 7.4-fold enhancement of activity. We characterized the process of in situ generation of nanoceria at pH 7.0 and how proteins boost the activity by enhancing product desorption. In addition, the proposed one-pot bio-nanozyme cascade shows high stability and analytical performance for serum glucose with a detection limit of 5 μM.

The determination of volatile methylsiloxanes (VMSs) in municipal sewage has attracted great attention. Gas chromatography-mass spectrometry (GC-MS) is the most mature detection technique for VMSs, however, its instrumentation and operation cost are unfavorable in low- and middle-income countries. Herein, a novel and cost-effective strategy by using a 3D printed miniature microplasma optical emission spectrometer (μAED) as an alternative to MS detector, was developed to detect VMSs in municipal sewage by GC after preconcentration by a laboratory-built automatic purge and trap (P&T) system. Two types of μAED s have been fabricated and their analytical performances were compared. The one using two tungsten rods as electrodes shows better performance and was thus selected as the detecting system for real sample analysis. Under the optimized conditions, the P&T-GC-μAED system provided limits of detection of 3.6 ng L−1 to 15.5 ng L−1 of Si for tested VMSs. Relative standard deviations were better than 3.0% and good recoveries ranging from 82.4% to 102.8% were obtained for all analytes. The applicability of this system was demonstrated via the measurement of VMSs in the influents and effluents from 10 wastewater treatment plants (WWTPs) in Chengdu, China.

Blood lead levels (BLL) of children have attracted considerable attention due to their putative impact on intelligence decline. However, most methods used for the determination of blood lead typically require expensive, bulky, high power and gas consuming instrumentation, limiting their application for a point-of-care diagnosis. Herein we report the development and testing of a portable ballpoint discharge microplasma optical emission spectrometer (BD-OES pen) device having the potential to fill this needed measurement capability. The BD-OES pen utilizes a compact ballpoint-pen format integrating point-discharge microplasma, which permits the determination of child BLL requiring no more than 100 μL blood while providing high specificity, sensitivity and satisfactory limit of detection (0.73 μg L

Objective The prognostic value of lymphovascular invasion (LVI), perineural invasion (PNI), and poor differentiation (PD) has been widely studied in different solid tumors. However, it was still controversial in adenocarcinoma of esophagogastric junction (AEG). We investigated the prognostic impact of combining LVI, PNI and PD for predicting the survival in patients with AEG.Methods We retrospectively investigated the data of patients who performed surgical resection of AEG on Guangdong Provincial Hospital and Guangdong Provincial Hospital of Chinese Medicine from Jan. 2004 to Dec. 2018. According to the status of LVI, PNI and differentiation, pathological adverse features were divided into three groups: 0, 1 or 2 and 3 adverse features, their impact on prognosis was evaluated. Results Univariate analysis indicated pT, pN, LVI , PNI , PD and pathological adverse features were risk factors for both overall survival (OS) and disease-specific survival (DSS), and multivariate analysis indicated that pathological adverse feature was independent risk factor for both OS and DSS. In subgroup analyses, adverse features were independent risk factor for DSS of stage II AEG but not for stage I or III.Conclusions The pathological adverse features were independent prognostic factors for AEG patients and they can help for further risk stratification in stage II patients.

A method for the rapid screening of toxic elements in fruits and vegetables is of significant importance to prevent human exposure to these elements. In this work, a simple method used for microplasma-induced vapor generation (μPIVG) was developed for the rapid screening and quantification of mercury in fruits and vegetables without sample preparation. A stainless-steel capillary was partly inserted into a juice droplet from the tested fruits and then the sample liquid automatically moved to the end of the capillary with the assistance of inherent capillary driving force. Subsequently, a high voltage was applied between the capillary and a tungsten electrode to generate microplasma wherein the juice was sprayed and the mercury ions contained in the juice were converted to mercury cold vapor (Hg0). The Hg0 was finally separated from the liquid phase and swept to an atomic fluorescence spectrometer (AFS) for rapid screening. A standard addition method coupled with μPIVG atomic fluorescence spectrometry was further used for the quantitative analysis of the suspected sample. Under the optimized conditions, the limits of detection (LODs) of 0.3, 0.5, and 0.4 μg L−1 were obtained for the tested tomato, lemon, and orange samples, respectively. The proposed technique provides a simple and cost-effective tool for the rapid screening of mercury in fruits and vegetables by atomic spectrometry.

Background: In adenocarcinoma of esophagogastric junction (AEG), the relationship between tumor size (TS) and lymph node metastasis (LNM) is unclear. This study aimed to explore the relationship between TS and LNM, and to construct a prediction model for LNM. Materials and Methods: Data from 4649 Siewert type II AEG patients were retrospectively acquired from the Surveillance, Epidemiology, and End Result (SEER) database. TS data was analyzed as a continuous variable, but also divided into 1-cm-interval categorical groups for further analysis. The logistic regression model and restricted cubic spline (RCS) model was used to explore the relationship between TS and LNM, after adjusting for covariates. Internal validations as well as external validation (Single-Center data) were used to check our LNM prediction model. Results: TS and LNM showed a significant relationship in the logistic regression analysis, regardless of the TS data being entered as a continuous or a categorical variable, after adjusting for covariates. The logistic regression model and RCS consistently showed that larger TS resulted in larger Odds Ratio (OR) values. When tumors were larger than 4 cm, the OR value remained relatively constant. The receiver operator characteristic curve evaluated the nomogram by the area under the curve (AUC) (AUC=0.737, in internal validation; AUC=0.626, in external validation), and the calibration curve of the nomogram showed an improved prediction system. Conclusions: In Siewert type II T1-T3 stage AEG patients, we reported that LNM increased with TS up to 4-cm, and our nomogram provided a simple tool to predict LNM.

Bioorthogonal control of metal ion sensors for imaging metal ions in living cells is important for better understanding of the distribution and fluctuation of metal ions. While bioorthogonal control using external stimuli such as light has been reported, these stimuli are not suitable for investigating many biological systems where light penetration is limited or quantum yield of activation is low. To overcome this limitation, we herein report the endogenous and bioorthogonal activation of a DNAzyme fluorescent sensor containing an 18-base pair (bp) recognition site of a homing endonuclease (I-SceI), since the recognition site of this length is found by chance only once in 7×10(10) bp of genomic sequences, it can thus form a near bioorthogonal pair with I-SceI for DNAzyme activation with minimal effect on living cells. The formation of the recognition site through double stranded DNA hybridization prevents the formation of an active DNAzyme initially. Once I-SceI is expressed inside cells, it cleaves at the recognition site, which allows the DNAzyme to adopt its active conformation. The activated DNAzyme sensor is then able to specifically catalyze cleavage of a substrate strand in the presence of Mg(2+) to release the fluorophore-labeled DNA fragment and produce a fluorescent turn-on signal for Mg(2+). Using this method, we demonstrate the use of I-SceI to activate the 10–23 DNAzyme for imaging of Mg(2+) in HeLa cells with endogenous and bioorthogonal control.

BACKGROUND AND OBJECTIVES The impact of SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery score (SS) and SS II in patients who receive percutaneous coronary intervention with second-generation everolimus-eluting stents (EES) has not been fully validated. METHODS The SS, SS II were calculated in 1,248 patients with left main and/or 3-vessel disease treated with EES. Patient-oriented composite endpoint (POCE; all-cause death, any myocardial infarction (MI), any revascularization) and target lesion failure (TLF: cardiac death, target-vessel MI, target lesion revascularization) were analyzed. RESULTS The mean SS was 21.1±9.6. Three-year POCE increased according to the SS group (15.2% vs. 19.9% vs. 27.4% for low (≤22), intermediate (≥23, ≤32), high (≥33) SS groups, p

A disposable, instrument-free, height readout paper-based analytical device (HR-PAD) based on a paper strip inkjet-printed with CdTe quantum dots (QDs) was developed for the sensitive speciation analysis of Ag+ and silver nanoparticles (AgNPs). When the paper strip is immersed into a sample solution, capillary action draws it through the surface and any Ag+ in the solution quenches the fluorescence of CdTe QDs via a cation exchange reaction between Ag+ and the CdTe QDs, with the height of the quenched band being proportional to the concentration of Ag+. In contrast, fluorescence quenching cannot be observed when only AgNPs are present in solution. Thus, the concentration of AgNPs can be obtained by subtracting the Ag+ content from the total silver determined by the HR-PAD after digestion with HNO3. Under optimized conditions, the methodology provides high selectivity, sensitivity, and accuracy for the detection of Ag+ or AgNPs in various samples, even at concentrations as low as 0.05 mg L-1. Precisions of 4.5% and 2.2% RSDs were achieved at concentrations of 1 mg L-1 and 7 mg L-1 of Ag+, respectively. Compared to conventional methods, this approach is inexpensive and user-friendly and eliminates the need for expensive and sophisticated detection instruments. The practicality of the method was demonstrated via the speciation analysis of AgNPs and Ag+ in river water and 12 commercial products with satisfactory results.

A new chemical vapor generation method coupled with headspace solid-phase microextraction miniaturized point discharge optical emission spectrometry (HS-SPME-μPD-OES) for the sensitive and matrix effect-free detection of nitrite in complex samples is described. In an acidic medium, the volatile cyclohexene was generated from cyclamate in the presence of nitrite, which was volatilized to the headspace of the container, efficiently separated, and preconcentrated by HS-SPME. Consequently, the SPME fiber was transferred to a laboratory-constructed thermal desorption chamber wherein the cyclohexene was thermally desorbed and swept into μPD-OES for its sensitive quantification via monitoring the carbon atomic emission line at 193.0 nm. As a result, the quantification of nitrite was accomplished through the determination of cyclohexene. The application of HS-SPME as a sampling technique not only simplifies the experimental setup of μPD-OES but it also preconcentrates and separates cyclohexene from N2 and sample matrices, thus eliminating the interference from water vapor and N2 and significantly improving the analytical performance on the determination of nitrite. Under the optimum experimental conditions, a limit of detection of 0.1 μg L-1 was obtained, which is much better than that obtained by conventional methods. The precision, expressed as relative standard deviation, was better than 3.0% at a concentration of 10 μg L-1. The proposed method provides several advantages of portability, simplicity, high sensitivity, and low energy consumption and eliminates expensive instruments and matrix interference, thus retaining a promising potential for the rapid, sensitive, and field analysis of nitrite in various samples.

DNAzymes have emerged as a powerful class of sensors for metal ions due to their high selectivity over a wide range of metal ions, allowing for on-site and real-time detection. Despite much progress made in this area, detecting and quantifying tightly bound metal ions, such as those in the blood serum, remain a challenge because the DNAzyme sensors reported so far can detect only mobile metal ions that are accessible to bind the DNAzymes. To overcome this major limitation, we report the use of a photocaged chelator, XDPAdeCage to extract the Zn(2+) from the blood serum and then release the chelated Zn(2+) into a buffer using 365 nm light for quantification by an 8–17 DNAzyme sensor. Protocols to chelate, uncage, extract, and detect metal ions in the serum have been developed and optimized. Because DNAzyme sensors for other metal ions have already been reported and more DNAzyme sensors can be obtained using in vitro selection, the method reported in this work will significantly expand the applications of the DNAzyme sensors from sensing metal ions that are not only free but also bound to other biomolecules in biological and environmental samples.