Modified stochastic diffusion particle-tracking model (MSDPTM) incorporating energy cascade theory and eddy intermittency for suspended sediment transport in open channel flow.

This study presents a modified stochastic diffusion particle tracking model (MSDPTM) that incorporates energy cascade theory to more accurately simulate suspended sediment transport. The impact of turbulent eddies on sediment particles is an intermittent process, which is also considered in this study. The study examines the time correlation between eddies using eddy turnover time and finds that closer-scale eddies exhibit higher correlations than those farther apart. The statistical properties of particle movement, such as the ensemble mean and variance of particle trajectories, have been calculated and compared with the stochastic diffusion particle tracking model (SDPTM) results. Notably, MSDPTM with intermittency demonstrates a significantly larger ensemble mean of particle trajectories in the streamwise direction than other particle tracking models. The proposed model is validated through comparison with available data, showing its enhanced performance. The results of the simulation indicate that MSDPTM outperforms SDPTM, especially when the intermittency effect of eddies is considered.

Cerium Synchronous Doping in Anatase for Enhanced Photocatalytic Hydrogen Production from Ethanol-Water Mixtures.

Cerium element with a unique electric structure can be used to modify semiconductor photocatalysts to enhance their photocatalytic performances. In this work, Ce-doped TiO2 (Ce/TiO2) was successfully achieved using the sol-gel method. The structural characterization methods confirm that Ce was doped in the lattice of anatase TiO2, which led to a smaller grain size. The performance test results show that the Ce doped in anatase TiO2 significantly enhances the charge transport efficiency and broadens the light absorption range, resulting in higher photocatalytic performance. The Ce/TiO2 exhibited a photocurrent density of 10.9 µA/cm2 at 1.0 V vs. Ag/AgCl, 2.5 times higher than that of pure TiO2 (4.3 µA/cm2) under AM 1.5 G light. The hydrogen (H2) production rate of the Ce/TiO2 was approximately 0.33 µmol/h/g, which is more than twice as much as that of the pure anatase TiO2 (0.12 µmol/h/g). This work demonstrates the effect of Ce doping in the lattice of TiO2 for enhanced photocatalytic hydrogen production.

Cerium-Doped Iron Oxide Nanorod Arrays for Photoelectrochemical Water Splitting.

In this work, a simple one-step hydrothermal method was employed to prepare the Ce-doped Fe2O3 ordered nanorod arrays (CFT). The Ce doping successfully narrowed the band gap of Fe2O3, which improved the visible light absorption performance. In addition, with the help of Ce doping, the recombination of electron/hole pairs was significantly inhibited. The external voltage will make the performance of the Ce-doped sample better. Therefore, the Ce-doped Fe2O3 has reached superior photoelectrochemical (PEC) performance with a high photocurrent density of 1.47 mA/cm2 at 1.6 V vs. RHE (Reversible Hydrogen Electrode), which is 7.3 times higher than that of pristine Fe2O3 nanorod arrays (FT). The Hydrogen (H2) production from PEC water splitting of Fe2O3 was highly improved by Ce doping to achieve an evolution rate of 21 µmol/cm2/h.

Pollen Carbon-Based Rare-Earth Composite Material for Highly Efficient Photocatalytic Hydrogen Production from Ethanol-Water Mixtures.

The unique electronic structure of rare-earth elements makes their modified semiconductor photocatalysts show great advantages in solar energy conversion. Herein, the pollen-like N, P self-doped biochar-based rare-earth composite catalyst (Er/LP-C) has been successfully synthesized, which combines the advantages of biochar and Er and is used for the first time in the field of photocatalytic hydrogen production from ethanol-water mixtures. Experimental results confirmed that the performance of photocatalytic hydrogen production under the full spectrum is up to 33.70 µmol/g in 6 h; this is due to the introduction of Er, which improves the carrier concentration, separation and transfer efficiency, and the driving force for the reduction reaction.

N, P Self-Doped Porous Carbon Material Derived from Lotus Pollen for Highly Efficient Ethanol-Water Mixtures Photocatalytic Hydrogen Production.

Porous biochar materials prepared with biomass as a precursor have received widespread attention. In this work, lotus pollen (LP) was used as the carbon source, a variety of the pollen carbon photocatalyst were prepared by a two-step roasting method. A series of characterizations were carried out on the prepared samples, and it was found that the average particle size was about 40 µm. They also exhibit a typical amorphous carbon structure and a porous structure with a network-like interconnected surface. The photocatalytic hydrogen production performances of lotus pollen carbon (LP-C) and commercial carbon black (CB) were measured under the full spectrum illumination. LP-C-600 showed the best hydrogen production performance (3.5 µmol·g-1·h-1). In addition, the photoelectrochemical (PEC) measurement results confirmed that the LP-C materials show better incident photon-current efficiency (IPCE) performance than the CB materials in the neutral electrolyte. This is because the unique surface wrinkling, hierarchical porous structure, and the N, P self-doping behavior of the LP-C samples are able to improve the light utilization efficiency and the carrier separation/transfer efficiency, thereby further improving the overall hydrogen production efficiency.

Risk of dental malocclusion in children with upper respiratory tract disorders: A case-control study of a nationwide, population-based health claim database.

OBJECTIVES: The aim of this study was to evaluate the association between different upper respiratory tract disorders and severe dental malocclusion in pediatric patients. METHODS: Newly diagnosed patients (N = 773) with dental malocclusion aged 8-18 years and controls (N = 3865) were identified from the health claim records of the Longitudinal Health Insurance Database 2000 of Taiwan's National Health Insurance Research Database. Controls were frequency matched to the cases by sex, age group, and index year. Univariate and multiple logistic regression analyses were used to evaluate the association between severe dental malocclusion and six common upper respiratory tract disorders, including acute sinusitis, allergic rhinitis, chronic sinusitis, nasal septum deviation, nasal polyps, and hypertrophy of tonsil and adenoids. RESULTS: The risk of severe dental malocclusion was significantly elevated in pediatric patients with three upper respiratory tract disorders, including acute sinusitis (adjusted odds ratio [aOR] = 1.66, 95% confidence interval [95% CI] 1.39-1.99), allergic rhinitis (aOR = 1.64, 95% CI 1.34-2.02), and chronic sinusitis (aOR = 2.01, 95% CI 1.27-3.19). When all the six upper respiratory tract disorders were simultaneously included in the multiple logistic regression analysis, acute sinusitis (aOR = 1.48, p < 0.001) and allergic rhinitis (aOR = 1.34, p < 0.010) were significantly and independently associated with an increased risk of severe dental malocclusion. CONCLUSIONS: Findings from this nationwide, population-based case-control study indicated that acute sinusitis and allergic rhinitis were independently and significantly associated with an increased risk of severe dental malocclusion in pediatric patients. Pediatricians should remain vigilant for the risk of dental malocclusion in their patients with these disorders.

Highly Pathogenic Avian Influenza H5 Hemagglutinin Fused with the A Subunit of Type IIb Escherichia coli Heat Labile Enterotoxin Elicited Protective Immunity and Neutralization by Intranasal Immunization in Mouse and Chicken Models.

Highly pathogenic avian influenza viruses are classified by the World Organization for Animal Health (OIE) as causes of devastating avian diseases. This study aimed to develop type IIb Escherichia coli heat-labile enterotoxin (LTIIb) as novel mucosal adjuvants for mucosal vaccine development. The fusion protein of H5 and LTIIb-A subunit was expressed and purified for mouse and chicken intranasal immunizations. Intranasal immunization with the H5-LTIIb-A fusion protein in mice elicited potent neutralizing antibodies in sera and bronchoalveolar lavage fluids, induced stronger Th1 and Th17 cellular responses in spleen and cervical lymph nodes, and improved protection against H5N1 influenza virus challenge. More interestingly, intranasal immunization with the H5-LTIIb-A fusion protein in chickens elicited high titers of IgY, IgA, hemagglutinin inhibition (HAI), and neutralizing antibodies in their antisera. This study employed the novel adjuvants of LTIIb for the development of a new generation of mucosal vaccines against highly pathogenic avian influenza viruses.

[Spatial management strategy of Zhujiajian Island based on island ecological vulnerability simulation]. / 基于海岛生态脆弱性模拟的朱家尖岛空间管控对策.

In the past decade, the number of islands fixed link with mainland has been increasing rapidly. The construction of such projects improves the accessibility of islands, which results in a rapid increase of tourists and economic income. However, the rapid change of land use and increases of tourists will make the islands more vulnerable. It is urgent to formulate ecosystem management strategy for island ecosystems based on the scientifical prediction of the island ecological vulnerability and accurate identification of sensitive areas. Island ecological vulnerability assessment model was used to evaluate the ecological vulnerability of Zhujiajian Island. Taking 2015 as the starting date, we simulated the changes of tourists and land use, as well as the changes of island ecological vulnerability in the next 20 years. Then, the management strategy was formulated based on the vulnerability assessment and sensitive analysis. The results showed that the ecosystem of Zhujiajian Island was in good condition now, with limited area at moderate and severe vulnerable status. With the rapid increases of tourists and island development intensity, the ecological vulnerability of the island tended to more vulnerability with the increases of severe vulnerability and shrink of low vulnerability. According to the vulnerability assessment and sensitivity analysis, the Zhujiajian Island could be divided into prohibited development zones, restricted development zones and conditional development zones with different ecosystem management strategies.

Acute rhinosinusitis among pediatric patients with allergic rhinitis: A nationwide, population-based cohort study.

BACKGROUND: While chronic rhinosinusitis is a common complication of allergic rhinitis, the link between acute rhinosinusitis and allergic rhinitis is unclear. The aim of this study was to evaluate the risk of incident acute rhinosinusitis among pediatric patients with allergic rhinitis, using a nationwide, population-based health claims research database. METHODS: Newly diagnosed allergic rhinitis patients aged 5-18 years were identified from the health claim records of the Longitudinal Health Insurance Database 2000 of Taiwan's National Health Insurance Research Database. A comparison cohort was assembled by randomly selecting patients from the same database with frequency matching by sex, age group, and index year. All patients were followed until a diagnosis of acute rhinosinusitis or the end of the follow-up period. Cox proportional hazards model was used to assess the association between allergic rhinitis and acute rhinosinusitis. RESULTS: Of the 43,588 pediatric patients included in this study, 55.4% were male and 43.9% were between the ages of 5.0-7.9 years. The risk of acute rhinosinusitis was significantly higher in pediatric patients with allergic rhinitis compared to those without the condition (adjusted hazard ratio = 3.03, 95% confidence interval = 2.89-3.18). Similar hazard ratios were observed between male and female pediatric patients. CONCLUSIONS: This secondary cohort study using a nationwide, population-based health claim data of the Taiwan's NHIRD showed that allergic rhinitis was significantly associated with a higher risk of acute rhinosinusitis among pediatric patients.

Simple obstructive sleep apnea patients without hypertension or diabetes accelerate kidney dysfunction: a population follow-up cohort study from Taiwan.

BACKGROUNDS: Obstructive sleep apnea (OSA) is common in patients on hemodialysis, but its correlation with chronic kidney disease (CKD) is not clear. We aimed to clarify the relationship between OSA without hypertension or diabetes and incidence of CKD in Taiwan. METHODS: This population-based cohort study consisted of patients with newly diagnosed OSA between 2000 and 2009. The comparison cohort was matched for age, sex, diabetes mellitus, and hypertension. All subjects previously diagnosed with acute or chronic kidney disease were excluded. The primary end point was newly diagnosed CKD. RESULTS: We identified 6866 subjects with OSA during the 10-year study period. The median duration until development of CKD in the OSA cohort was 3.2 years, 2.5 months earlier than that in the non-OSA cohort. After exclusion of hypertension and diabetes, 4319 OSA patients was identified and the hazard ratio (HR) of CKD with OSA was 1.37 (95 % confidence interval [CI], 1.05-1.77; p = 0.019). In the subgroup analysis, an increased incidence of CKD in OSA was observed in women (HR, 1.41; 95 % CI, 1.12-1.78; p = 0.0036). CONCLUSIONS: This longitudinal population-based cohort study provides evidence that patients with OSA even without diabetes or hypertension are at higher risk of developing CKD over the next 3 years and nearly 2.5 months earlier than the non-OSA cohort, particularly women.

Comparative proteomic analysis of Litopenaeus vannamei gills after vaccination with two WSSV structural proteins.

White spot syndrome virus (WSSV) is one of the most devastating viral pathogens of cultured shrimp worldwide. Recently published papers show the ability of WSSV structural protein VP28 to vaccinate shrimp and raise protection against the virus. This study attempted to identify the joining proteins of the aforementioned shrimp quasi-immune response by proteomic analysis. The other envelope protein, VP36B, was used as the non-protective subunit vaccine control. Shrimp were intramuscularly injected with rVPs or PBS on day 1 and day 4 and then on day 7 their gill tissues were sampled. The two-dimensional electrophoresis (2-DE) patterns of gill proteins between vaccinated and PBS groups were compared and 20 differentially expressed proteins identified by mass spectrometry, some of which were validated in gill and hemocyte tissues using real-time quantitative RT-PCR. Many of identified proteins and their expression levels also linked with the shrimp response during WSSV infection. The list of up-regulated protein spots found exclusively in rVP28-vaccinated shrimp include calreticulin and heat shock protein 70 with chaperone properties, ubiquitin, and others. The two serine proteases, chymotrypsin and trypsin, were significantly increased in shrimp of both vaccinated groups compared to PBS controls. The information presented here should be useful for gaining insight into invertebrate immunity.

Single-Crystalline Aluminum Nanostructures on a Semiconducting GaAs Substrate for Ultraviolet to Near-Infrared Plasmonics.

Aluminum, as a metallic material for plasmonics, is of great interest because it extends the applications of surface plasmon resonance into the ultraviolet (UV) region and is superior to noble metals in natural abundance, cost, and compatibility with modern semiconductor fabrication processes. Ultrasmooth single-crystalline metallic films are beneficial for the fabrication of high-definition plasmonic nanostructures, especially complex integrated nanocircuits. The absence of surface corrugation and crystal boundaries also guarantees superior optical properties and applications in nanolasers. Here, we present UV to near-infrared plasmonic resonance of single-crystalline aluminum nanoslits and nanoholes. The high-definition nanostructures are fabricated with focused ion-beam milling into an ultrasmooth single-crystalline aluminum film grown on a semiconducting GaAs substrate with a molecular beam epitaxy method. The single-crystalline aluminum film shows improved reflectivity and reduced two-photon photoluminescence (TPPL) due to the ultrasmooth surface. Both linear scattering and nonlinear TPPL are studied in detail. The nanoslit arrays show clear Fano-like resonance, and the nanoholes are found to support both photonic modes and localized surface plasmon resonance. We also found that TPPL generation is more efficient when the excitation polarization is parallel rather than perpendicular to the edge of the aluminum film. Such a counterintuitive phenomenon is attributed to the high refractive index of the GaAs substrate. We show that the polarization of TPPL from aluminum preserves the excitation polarization and is independent of the crystal orientation of the film or substrate. Our study gains insight into the optical property of aluminum nanostructures on a high-index semiconducting GaAs substrate and illustrates a practical route to implement plasmonic devices onto semiconductors for future hybrid nanodevices.

Dengue virus nonstructural protein NS1 binds to prothrombin/thrombin and inhibits prothrombin activation.

OBJECTIVES: Dengue virus (DENV) infection may result in severe dengue hemorrhage fever (DHF). However the mechanisms to cause hemorrhage during DENV infection are not fully understood. The sera level of secreted DENV nonstructural protein 1 (NS1) is correlated with the development of DHF. However, whether secreted NS1 can interfere with coagulation and contribute to the hemorrhage in DHF is unknown. Since thrombin plays a very important role in the activation of coagulation, we investigated whether NS1 can bind to thrombin and affect its formation or activity. METHODS AND RESULTS: We first demonstrated that NS1 could bind to thrombin and formed NS1/thrombin complex in dengue patients' sera by enzyme-linked immunosorbent assay (ELISA). The ability of NS1 binding to prothrombin or thrombin was further confirmed using recombinant NS1 (rNS1) by ELISA, co-immunoprecipitation, and rNS1-affinity column purification. Even though the binding of rNS1 to thrombin showed no effect on thrombin activity, rNS1 could inhibit prothrombin activation and prolong activated partial thromboplastin time (APTT) of human platelet poor plasma. CONCLUSION: These results suggest secreted DENV NS1 may bind to prothrombin and inhibit it activation, which in turn, may contribute to the APTT prolongation and hemorrhage in DHF patients.

Clinical spectrum of acute rhinosinusitis among atopic and nonatopic children in Taiwan.

BACKGROUND: Rhinitis and sinusitis are very common medical conditions and have been shown to be frequently associated. The role of allergies in the pathogenesis of chronic rhinosinusitis has been confirmed; however, the role of allergies in acute rhinosinusitis is debatable. Nonetheless, allergies are an important factor in the development of rhinosinusitis. OBJECTIVE: To evaluate the incidence of allergic rhinitis in patients with acute rhinosinusitis and identify the clinical spectrum in Taiwan. METHODS: This study randomly recruited 69 participants between 3 and 12 years of age with acute rhinosinusitis over the period of one and a half years. All participants underwent a nasal peak expiratory flow rate (nPEFR) test, skin-Prick test (SPT), nasal smear examination, nasal culture, radiography (Water's projection) and were requested to complete the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) as well as provide their allergic history. RESULTS: Among the 69 participants in the study, 27 (39.1%) participants were shown to have allergic rhinitis. The most troublesome symptoms among the 69 participants with acute rhinosinusitis were postnasal drip (3.00 ± 1.29), nasal obstruction (2.94 ± 1.39) and cough (2.67 ± 1.42). The most troublesome symptoms among the 27 participants with acute rhinosinusitis combined with allergic rhinitis were nasal obstruction (3.33 ± 1.24), postnasal drip (3.22 ± 1.09) and itchy eyes (2.74 ± 1.43) and with the higher values. In addition, the participants (≧ 6 y/o) with acute rhinosinusitis combined with allergic rhinitis had significantly lower nPEFR values compared with the nonatopic children (75.2 ± 18.2 vs 96.6 ± 21.4, p<0.05). If nPEFR is below 75 mL/min, the positive predict value in the patients of acute rhinosinusitis is 75.0% combined with allergic rhinitis (sensitivity 63.2%; specificity 85.7%). Streptococcus pneumoniae (29.0%), Haemophilus influenzae (20.3%), and Moraxella catarrhalis (17.4%) were the major isolated pathogens in this study. The prevalence of colonization with Staphylococcus aureus in the 69 participants with acute rhinosinusitis was 23.2%, and 15.9% for methicillin-resistant S. aureus (MRSA). CONCLUSION: This study demonstrated that the bacteriological properties of acute rhinosinusitis among children in Taiwan are the same as those in other parts of the world; however, the prevalence of colonization by MRSA was higher than among healthy children. Second, atopic children were more likely to develop acute rhinosinusitis than nonatopic children. Third, most Taiwanese children with acute rhinosinusitis complained of postnasal drip, nasal obstruction and cough. If a child suffering from acute rhinosinusitis complained of severe nasal obstruction (nPEFR≦75 mL/min), the doctor should be alerted to atopic conditions requiring further treatment. The issues dealt with in this study may require further research with a larger sample population over an extended period of time to verify these conclusions.

Experimental and numerical estimations into the force distribution on an occlusal surface utilizing a flexible force sensor array.

This study presents a novel flexible force sensor array for measuring the distribution of the force distribution over the first molar. The developed force sensor array is composed of a flexible polyimide electrode and barium-titanate-based multilayer ceramic capacitors (MLCCs). The piezoelectric and material properties of industrial-grade MLCCs are ideal for measuring large-force loadings. The sensors are cheap and easy to integrate with automated manufacturing processes. Prior to experimental measurements, the force responses for the MLCC sensor cells were systematically measured and evaluated, confirming their high fracture strength and good sensing properties. Finite element (FE) simulations were used to calculate the force distribution over the tooth crown from the measurement results of the 3×3 force sensor array. Results indicate that the sensor has great sensitivity and linearity under a high-speed cycle loading of 500 N/s conducted to simulate normal chewing. The total force measured using the developed sensor array within the artificial tooth had an error of less than 5%. In addition, the force distributions over the molar crown obtained using a numerical method of FE analysis agree well with those obtained from experiments. The developed flexible force sensor array thus has potential for in-situ bite force measurements that are low-cost and reliable.

New class of organic-inorganic hybrid aggregates based on polyoxometalates and metal-Schiff-base.

By combination of heteropolymolybdates and metal-Schiff-base complexes, two new organic-inorganic hybrid compounds {Mn(salen)(2)(H(2)O)(2)[AlMo(6)(OH)(6)O(18)]}[arg]·16H(2)O (1) and {Mn(salen)(2)(H(2)O)(2)[CrMo(6)(OH)(6)O(18)]}[arg]·11H(2)O (2) (salen = N,N'-ethylene-bis(salicylideneiminate) have been successfully isolated. Compounds 1 and 2 were structurally characterized by elemental analyses, IR spectra, thermogravimetric analysis, and single-crystal X-ray diffraction. To the best of our knowledge, compounds 1 and 2 represent the first single-crystal structures of metal-Schiff-base decorated polyoxometalates (POMs) compounds. Photocatalytic experiments indicated that both 1 and 2 exhibit high catalytic activity for photodegradation of RhB with UV irradiation. In addition, the magnetic properties of 1 were also investigated.

Digitally synchronized LCD projector for multi-color fluorescence excitation in parallel capillary electrophoresis detection.

A simple method is proposed for modulating the excitation light used for multi-color fluorescence detection in a single capillary electrophoresis (CE) channel. In the proposed approach, a low-cost commercial liquid crystal device (LCD) projector with digitally-modulated LCD switches is used to provide the illumination light source and the fluorescence emitted from the CE chip is synchronously detected using an ultraviolet-visible-near infrared (UV-vis-NIR) spectrometer. The modulated light source enables the detection of multiple fluorescence signals within a single CE channel without the need of mechanically switching optical components. In order to enhance the sensing performance of the proposed system, two short-pass filters and one band-pass filter are inserted into the LCD projector to modify the wavelength spectra for fluorescence excitation. With this simple approach, the signal-to-noise (SN) ratio of the fluorescence detection signals is greatly improved by a factor of approximately 22 when detecting Atto647N fluorescent dye. The feasibility of the proposed multi-color CE detection approach is demonstrated by detecting two different samples including a mixed sample comprising FITC, Rhodamine B and Atto647N fluorescent dyes and a bio-sample composed of two ssDNAs labeled with FITC and Cy3, respectively. Results confirm that the digitally-modulated excitation system proposed in this study has significant potential for the parallel analysis of fluorescently-labeled bio-samples using a multi-color detection scheme.

Objective-type dark-field system applied to multi-wavelength capillary electrophoresis for fluorescent detection and analysis.

This paper presents an advanced diascopic illumination technique for simultaneous multi-wavelength fluorescence excitation and detection without using any spatial filter sets. The proposed system includes a home-built dark-field condenser comprising a high N.A. objective and a light stop-film to excite fluorescence and an ultraviolet-visible-near infrared (UV-VIS-NIR) spectrometer to detect emitted signals. Since no direct light source enters the optical detection system, no complex optical filter is required for multi-wavelength fluorescence detection. This study also designs an optimized stop-film pattern to obtain the best performance in exciting fluorescent samples and reduce background light. Experimental results show that the proposed system can effectively increase the fluorescent signal and simultaneously detect a mixed sample composed of 2',7'-dichlorofluorescein, Rhodamine B, Atto610, and Atto647N. Furthermore, this proposed system successfully separates and detects a mixed bio-sample composed of three single-stranded DNA samples labeled with Cy3, FITC, and Alexa647 fluorescence in a single channel. A simple and fast calculation removes noise and fluorescent cross-effect for conveniently observing the electropherograms. The proposed system has a measured detection limit up to 5x10(-8)M (S/N=3) while detecting a standard fluorescence of 2',7'-dichlorofluoresein, which is capable of detecting fluorescence samples in general applications. The proposed method provides a simple and straightforward way to detect multi-wavelength fluorescence for CE analysis.

Novel wavelength-resolved fluorescence detection for a high-throughput capillary electrophoresis system under a diascopic configuration.

This paper presents a novel method regarding a wavelength-resolved fluorescence detection scheme for high-throughput analysis of bio-samples in a micro-CE chip. Instead of using the conventional laser-induced fluorescence (LIF) microscope equipped with delicate spatial filters and complex control systems, this study adopts a hollow cone illumination generated using a dark-field condenser for exciting fluorescence in the microchannel and an ultraviolet-visible-near-infrared (UV-Vis-NIR) spectrometer for detecting the emission signals. Experimental results show that the proposed system is feasible for simultaneously detecting a mixed sample composed of Atto 610, Rhodamine B and fluorescein isothiocyanate (FITC) fluorescent dyes in a single test run. Furthermore, a mixed bio-sample composed of two mixed 16-mer single-stranded DNAs labeled with Cy3 and FITC fluorescent dyes is also successfully detected with the proposed system. The measured limit of detection (LOD) for detecting FITC of the proposed system can be as low as 5.4x10(-6)M (S/N=3). This proposed detection method has shown its potential on RNA identification and DNA sequencing applications.

Determination of flunitrazepam and 7-aminoflunitrazepam in human urine by on-line solid phase extraction liquid chromatography-electrospray-tandem mass spectrometry.

A method using an on-line solid phase extraction (SPE) and liquid chromatography with electrospray-tandem mass spectrometry (LC-ES-MS/MS) for the determination of flunitrazepam (FM2) and 7-aminoflunitrazepam (7-aminoFM2) in urine was developed. A mixed mode Oasis HLB SPE cartridge column was utilized for on-line extraction. A reversed phase C(18) LC column was employed for LC separation and MS/MS was used for detection. Sample extraction, clean-up and elution were performed automatically and controlled by a six-port valve. Recoveries ranging from 94.8 to 101.3% were measured. For both 7-aminoFM2 and FM2, dual linear ranges were determined from 20 to 200 and 200-2000ng/ml, respectively. The detection limit for each analyte based on a signal-to-noise ratio of 3 ranged from 1 to 3ng/ml. The intra-day and inter-day precision showed coefficients of variance (CV) ranging from 4.6 to 8.5 and 2.6-9.2%, respectively. The applicability of this newly developed method was examined by analyzing several urine samples.