Redemitting BODIPY boronic acid fluorescent sensors for detection of lactate

Two redemitting BODIPY boronic acid pinacolate derivatives, sensors 1 and 2 were shown to act as excellent and highly selective lactate detectors at physiological pH (7.4), where the formed sensor-lactate complexes exhibited a significant emission and absorption increase. Since hyperlactataemia ([l-lac] > 6.5 mM) is a common complication in intensive care units, there is need for easy, on-line monitoring of lactate levels in patients. Semi-invasive monitoring via a lactate electrode or optic fiber would be attractive. This may beneficially replace existing lactate detection methods requiring a high degree of instrumentation. Sensors 1 and 2 can detect lactate without interference from biological important monosaccharides, such as d-glucose, d-fructose and d-mannose.     

Determination of rifampicin in human plasma by high‐performance liquid chromatography coupled with ultraviolet detection after automatized solid–liquid extraction

A precise and accurate high‐performance liquid chromatography (HPLC) quantification method of rifampicin in human plasma was developed and validated using ultraviolet detection after an automatized solid‐phase extraction. The method was validated with respect to selectivity, extraction recovery, linearity, intra‐ and inter‐day precision, accuracy, lower limit of quantification and stability. Chromatographic separation was performed on a Chromolith RP₈ column using a mixture of 0.05 m acetate buffer pH 5.7–acetonitrile (35:65, v/v) as mobile phase. The compounds were detected at a wavelength of 335 nm with a lower limit of quantification of 0.05 mg/L in human plasma. Retention times for rifampicin and 6,7‐dimethyl‐2,3‐di(2‐pyridyl) quinoxaline used as internal standard were respectively 3.77 and 4.81 min. This robust and exact method was successfully applied in routine for therapeutic drug monitoring in patients treated with rifampicin.     

A continuous flow-batch hybrid reactor for commodity chemical synthesis enabled by inline NMR and temperature monitoring

Inline, real time NMR and temperature measurements have been used to optimise the continuous flow synthesis of difluoromethyltrimethylsilane (TMSCF₂H) by the reduction of the Ruppert-Prakash reagent (TMSCF₃). These measurements were used to maximise the space-time-yield, while ensuring this exothermic process remains safe. In this way, a three-fold increase in space-time-yield was achieved compared to the reported batch procedure, isolating 25?g of pure TMSCF₂H after 105?min.     

Opto‐electrochemical In Situ Monitoring of the Cathodic Formation of Single Cobalt Nanoparticles

Single‐particle electrochemistry at a nanoelectrode is explored by dark‐field optical microscopy. The analysis of the scattered light allows in situ dynamic monitoring of the electrodeposition of single cobalt nanoparticles down to a radius of 65 nm. Larger sub‐micrometer particles are directly sized optically by super‐localization of the edges and the scattered light contains complementary information concerning the particle redox chemistry. This opto‐electrochemical approach is used to derive mechanistic insights about electrocatalysis that are not accessible from single‐particle electrochemistry.     

Fast and sensitive analysis of beta blockers by ultra‐high‐performance liquid chromatography coupled with ultra‐high‐resolution TOF mass spectrometry

This paper presents a method for the determination of acebutolol, betaxolol, bisoprolol, metoprolol, nebivolol and sotalol in human serum by liquid–liquid extraction and ultra‐high‐performance liquid chromatography coupled with ultra‐high‐resolution TOF mass spectrometry. After liquid–liquid extraction, beta blockers were separated on a reverse‐phase analytical column (Acclaim RS 120; 100 × 2.1 mm, 2.2 μm). The total run time was 6 min for each sample. Linearity, limit of detection, limit of quantification, matrix effects, specificity, precision, accuracy, recovery and sample stability were evaluated. The method was successfully applied to the therapeutic drug monitoring of 108 patients with hypertension. This method was also used for determination of beta blockers in 33 intoxicated patients.     

Studies on excretion kinetics of ten constituents in rat urine after oral administration of Shensong Yangxin Capsule by UPLC‐MS/MS

A rapid and sensitive ultra‐high performance liquid chromatography–mass spectrometry (UPLC‐MS/MS) method was developed and validated for the quantification of 10 major active constituents in rat urine after oral administration of Shensong Yangxin Capsule (SSYX) using diazepam as an internal standard (IS). The urine samples were pretreated and extracted by solid‐phase extraction prior to UPLC. Chromatographic separation was achieved on a Waters C₁₈ (2.1 × 50 mm, 1.7 µm) column using a gradient elution program with 0.1% formic acid aqueous solution and acetonitrile at a flow rate of 0.4 mL/min. Detection and quantitation were accomplished by a hybrid quadrupole mass spectrometer using electrospray ionization source and multiple reaction monitoring in the positive ionization mode. The mass transition ion‐pairs (m/z) for quantitation were all optimized and the total run time was 4.50 min. The specificity, linearity, accuracy, precision, recovery, matrix effect and stabilities were all validated for the analytes in urine samples. The validation results indicated that this method was simple, rapid, specific and reliable. The proposed method was successfully applied to investigate the urinary excretion kinetics of 10 compounds in rat after oral administration of SSYX. Copyright © 2013 John Wiley & Sons, Ltd.     

An ultrasensitive method of real time pH monitoring with complementary metal oxide semiconductor image sensor

CMOS sensors are becoming a powerful tool in the biological and chemical field. In this work, we introduce a new approach on quantifying various pH solutions with a CMOS image sensor. The CMOS image sensor based pH measurement produces high-accuracy analysis, making it a truly portable and user friendly system. pH indicator blended hydrogel matrix was fabricated as a thin film to the accurate color development. A distinct color change of red, green and blue (RGB) develops in the hydrogel film by applying various pH solutions (pH 1–14). The semi-quantitative pH evolution was acquired by visual read out. Further, CMOS image sensor absorbs the RGB color intensity of the film and hue value converted into digital numbers with the aid of an analog-to-digital converter (ADC) to determine the pH ranges of solutions. Chromaticity diagram and Euclidean distance represent the RGB color space and differentiation of pH ranges, respectively. This technique is applicable to sense the various toxic chemicals and chemical vapors by situ sensing. Ultimately, the entire approach can be integrated into smartphone and operable with the user friendly manner.     

Toxicity biomonitoring of degradation byproducts using freeze-dried recombinant bioluminescent bacteria

A toxicity biomonitoring system using freeze-dried recombinant bioluminescent bacteria was implemented to diagnose the biotreatment of 2,4,5-trichlorophenol and its degradation byproducts of using a cell-free culture broth of Phanerochaete chrysosporium. The cellular toxicity was measured by the bioluminescence of constitutive bioluminescent bacteria, such as Photobacterium phosphoreum and GC2, while information on the toxicity caused by unknown byproducts was obtained using the specific bioluminescent responses of stress-inducible bioluminescent bacteria, which included DPD2540 (membrane-damage sensitive), TV1061 (protein-damage sensitive), DPD2794 (DNA-damage sensitive), and DPD2511 (oxidative-damage sensitive) strains. An overall decrease in the cellular toxicity was observed as the treatment progressed, i.e. as 2,4,5-trichlorophenol disappeared. On the other hand, bioluminescent responses from DPD2511, DPD2540, and TV1061 increased as degradation progressed, most probably due to the formation of byproducts causing oxidative-, membrane-, and protein-damage. In conclusion, this toxicity biomonitoring method may be applied to evaluate the toxicities of degradation byproducts of the other environmental processes to provide more information about the mode of the byproducts’ toxicity.     

基坑施工变形事故分析及监控措施

基坑支护设计、施工应结合工程地质及土质参数、地下管网、水位及周围环境等综合因素实施，提出了施工过程引起基坑变形后的技术处理及监控措施。