A non-enzymatic disposable electrochemical sensor coupled with an automated sample pretreatment paper-based device was developed to avoid an additional sample preparation step for glucose determination in human urine and electrolyte drinks. The automated sample pretreatment paper-based device was successfully fabricated by the simple coating of a strong alkaline solution on a patterned wax paper, and then attached on an electrochemical sensor. The nanocomposite of copper oxide nanoparticles, ionic liquid and reduced graphene oxide (CuO-IL/rGO) modified on the screen-printed carbon electrode (SPCE) was created and used as a non-enzymatic electrochemical glucose sensor. The presence of the CuO-IL/rGO nanocomposite on the screen-printed electrode surface was confirmed by transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction spectroscopy (XRD). Under optimal conditions, glucose was measured by dropping 100 μL sample solution on the device and detected via chronoamperometry (CA) using a smartphone potentiostat controlled by Android app., providing a rapid current response within 20 s and linearity in a range of 0.03-7.0 mM with a limit of detection (LOD) of 0.14 μM. Furthermore, this developed device was successfully applied for determining glucose levels in human urine and electrolyte drinks, exporting satisfying results correlated with a commercial enzymatic glucose biosensor and labeled values of the commercial products. Therefore, this device could be an alternative device for a non-enzymatic glucose sensor with single-step sample loading, allowing for real-time analysis, low cost, portability, disposability, and on-field measurement.

Aim. Assessment of the capabilities of planar scanning combined with X-ray computed tomography in the diagnosis of neck masses.
 Methods. The study included 9 patients with neck masses examined at Rostov Scientific Research Institute of Oncology. Patients with suspected retrosternal nodal growth and ectopic thyroid gland on clinical and ultrasound examinations received single-photon emission computed tomography combined with computed tomography. The technique included the following stages: (1) planar scanning; (2) volumetric dynamic emission tomography of relevant areas; (3) X-ray spiral computed tomography; (4) archiving, combining scan parameters; (5) post-processing and reconstruction of images and assessment of the results.
 Results. Ultrasound study of neck masses in our study did not provide complete evaluation of surrounding anatomical structures due to large size of masses and did not allow identifying the connection between mass lesions and thyroid gland and evaluating relationship between the tumor and trachea, esophagus, great vessels. As a result of our study, with the use of single-photon emission computed tomography combined with computed tomography, among 9 patients with neck masses 5 (55.5%) patients were diagnosed with retrosternal thyroid lesions, 3 (33.3%) - ectopic thyroid gland and 1 (11.2%) - metastasis of neuroendocrine (small cell) carcinoma. 3 (60%) out of 5 patients with retrosternal thyroid lesions had a nodular goiter with retrosternal component and 2 (40%) patients had thyroid cancer with a nodular goiter. Conclusions. A combination of hybrid technologies of single-photon emission computed tomography and computed tomography for the identification of neck masses is a highly informative method providing single-step determination of the lesion location and assessment of its topographic and anatomical relationship with surrounding anatomical structures which allows optimizing the examination and choosing further management strategy.

Simultaneous determination of trace concentrations of aldehydes and carboxylic acids in particulate matter

The competition association binding method allows the characterization of the kinetics of unlabeled compounds and the calculation of receptor-drug affinity (K d). The K d value is defined as the ratio of the dissociation constant (or k off) of the receptor-bound ligand to its association rate constant (or k on) for a system at equilibrium. Traditionally, competition association binding experiments have been carried out using radiometric detection methods with limited assay throughput. Here we describe a novel method for the determination of unlabeled compound kinetics using the technique of time-resolved fluorescence resonance energy transfer (TR-FRET) performed at physiological temperature and sodium ion concentration. Based on a traditional screening format (10-point curves), up to 28 compounds can be tested on a single 384-well plate by this method.

Determination of pyrophosphate and sulfate using polyhexamethylene guanidine hydrochloride-stabilized silver nanoparticles

Simple and rapid method for screening of pyrophosphate using 6,6-ionene-stabilized gold and silver nanoparticles

A colorimetric probe based on desensitized ionene-stabilized gold nanoparticles for single-step test for sulfate ions

Quantitative determination of zopiclone and its impurity by four different spectrophotometric methods

Department of Chemistry, Sathyabama University, Chennai-600 119, India <em>E-mail</em> : jkarthik _ chem@rediffmail.com, dr .j.karthikeyan@gmail.com Department of Chemistry, Sahyadri Science College, Shimoga-577 203, Karnataka, India Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Srinivasnagar-575 025, Karnataka, India <em>Manuscript received online 25 September 2012, revised 03 October 2012, accepted 03 October 2012</em> <em>p</em>-[<em>N,N</em>-Bis(2-chloroethyl)amino]benzaldehyde thiosemicarbazone is proposed as an analytical reagent for the spectrophotometric determination of platinum(IV). The reagent forms yellow colored complex with platinum(IV) in the concentration range of 0.016-0.080 <em>M</em> hydrochloric acid medium. Beer's law is obeyed in the concentration range up to 12.48 µg cm-³. The optimum concentration range for minimum photometric error as determined by Ringbom's plot method is 3.12-10.92 µg cm^-3. The yellowish Pt^IV-reagent complex shows a maximum absorbance at 390 nm, with molar absorptivity of 2.05 x 10⁴ dm³ moI^- ¹ cm^-1and Sandell's sensitivity of the complex from Beer's data, for D = 0.001, is 0.012 µg cm^-2. The composition of the Pt^IV-CEABT complex is found to be 1 : 2 (M : L) by Job's method and by mole-ratio method. The relative error and coefficient of variation (<em>n</em> = 6) of the method does not exceed ±0.80% and ±0.32% respectively. The interference of various cations and anions in the method were studied. The proposed method was successfully used for the determination of Pt^IV in alloys, catalysts, complexes, environmental and pharmaceutical samples. The method is rapid as the Pt^IV-CEABT complex is soluble in water-ethanol-DMF medium and not requiring any time consuming extraction method for the complex.

Combining the isoabsorptive point in the ratio spectrum and the smart ratio difference methods for a single step determination of compounds with overlapped spectra

Single step determination of PCB 126 and 153 in rat tissues by using solid phase microextraction/gas chromatography–mass spectrometry: Comparison with solid phase extraction and liquid/liquid extraction

Characterization of Physical Properties of Supported Phospholipid Membranes Using Imaging Ellipsometry at Optical Wavelengths

BackgroundMutations in the mitochondrial DNA (mtDNA) have been reported in a wide variety of human neoplasms. A polynucleotide tract extending from 303 to 315 nucleotide positions (D310) within the non-coding region of mtDNA has been identified as a mutational hotspot of primary tumors. This region consists of two polycytosine stretches interrupted by a thymidine nucleotide. The number of cytosines at the first and second stretches are 7 and 5 respectively, according to the GeneBank sequence. The first stretch exhibits a polymorphic length variation (6-C to 9-C) among individuals and has been investigated in many cancer types. Large-scale studies are needed to clarify the relationship between cytosine number and cancer development/progression. However, time and money consuming methods such as radioactivity-based gel electrophoresis and sequencing, are not appropriate for the determination of this polymorphism for large case-control studies. In this study, we conducted a rapid RFLP analysis using a restriction enzyme, BsaXI, for the single step simple determination of 7-C carriers at the first stretch in D310 region.Methods25 colorectal cancer patients, 25 breast cancer patients and 41 healthy individuals were enrolled into the study. PCR amplification followed by restriction enzyme digestion of D310 region was performed for RFLP analysis. Digestion products were analysed by agarose gel electrophoresis. Sequencing was also applied to samples in order to confirm the RFLP data.ResultsSamples containing 7-C at first stretch of D310 region were successfully determined by the BsaXI RFLP method. Heteroplasmy and homoplasmy for 7-C content was also determined as evidenced by direct sequencing. Forty-one percent of the studied samples were found to be BsaXI positive. Furthermore, BsaXI status of colorectal cancer samples were significantly different from that of healthy individuals.ConclusionIn conclusion, BsaXI RFLP analysis is a simple and rapid approach for the single step determination of D310 polymorphism of mitochondrial DNA. This method allows the evaluation of a significant proportion of samples without the need for sequencing- and/or radioactivity-based techniques.

Large genomic duplications and deletions are increasingly recognized as a cause of human disease. Charcot-Marie-Tooth type 1A (CMT1A) and hereditary neuropathy with liability to pressure palsy (HNPP) result, respectively, from a duplication or deletion of a 1.5 Mb genomic region in 17p11.2-12, containing the PMP22 gene. In routine diagnostic analysis, CMT1A status is inferred from the detection of an imbalanced dosage of two alleles or the presence of three alleles of a polymorphic marker flanking the PMP22 gene. HNPP is suspected if only one allele is seen, but hemizygosity must be confirmed by analyzing allele segregation in the family or by other techniques such as Southern blotting or fluorescence in situ hybridization (FISH). PCR-based methodologies have also been developed that allow single-step determination of the PMP22 gene copy number, wherein amplicons are typically labeled and/or separated by gel electrophoresis. We describe here a fast and reliable PCR-based method for the diagnosis of CMT1A and HNPP in which the PMP22 gene is co-amplified with a reference gene, and the amplicons are separated according to their size and quantified by DHPLC. Our results suggest that this method for quantifying gene dosage could be applied to other genomic rearrangements.

Single step determination of fragrances in Cucurbita flowers by coupling headspace solid-phase microextraction low-pressure gas chromatography–tandem mass spectrometry

A preconcentration methodology utilizing the cloud point phenomenon is described for the determination of iron, cobalt and nickel by flame atomic absorption spectrometry (FAAS). The method employs the formation of complexes of the metallic species with ammonium pyrrolidinedithiocarbamate (APDC), which are subsequently entrapped in the micelles of the surfactant TX-114, upon increase of the solution temperature to 70 °C. The surfactant micelles, after their dilution to an acidified methanolic solution, are delivered to the nebulizer of the FAAS by a flow injection analysis (FIA) manifold, allowing for the reproducible injection of a small volume of the sample. The ability to handle the final texture of the injected solution allows for the single-step determination of these metal ions, in a single sample, without interferences. Analytical curves were rectilinear up to concentrations of 350 µg l−1 for Fe, 200 µg l−1 for Co and 250 µg l−1 for Ni with detection limits of 19, 5 and 11 µg l−1, respectively. The method was applied to the analysis of several real and spiked samples yielding satisfactory results. The recoveries obtained were in the range of 97–103% for spiked samples and 98–99.5% for a Certified Reference Material (CRM).

Posttraumatic malalignments are a frequent sequlae of IM nailing of lower extremity fractures. Conventional US has proven to be inferior to CT determinations of tibial or femural length and torsion. A new 3-D US method is presented that allows for accurate single step determination of lower extremity length and torsion without ionizing radiation. A regular US machine with a 5 Mhz linear probe is combined with an US localizer. Reference markers affixed to the lower extremity eliminate errors associated with patient position or motion. The 3-D US method was compared against CT (Ulm's method) in the measurement of torsion and length of the tibia and femur in 50 adults and 50 children. In both methods, the maximum difference of the intraindividual torsional angles and length measurements was 7 degrees and 7 mm. The maximum standard deviation for reproducibility in length measurement was 1.6 mm and 1.5 degrees for angular torsion. The new 3-D US technique was superior to CT in terms of reliability and reproducibility. Clinical advantages of the 3-D US technique include rapidity, independence from patient motion or positioning and the avoidance of ionizing radiation. Indications for 3-D torsional and length determinations include follow-up evaluation of adult and pediatric tibial and femoral fractures, pediatric limb and gait evaluations, and osteotomy planning.

Following an approach by Paczy\'nski & Stanek we compare red clump stars with parallaxes known to better than 10% in the Hipparcos catalog with the red clump stars observed in three fields in M31 using the HST. There are $\sim 600$ and $\sim 6,300$ such stars in the two data sets, respectively. The local red clump luminosity function is well represented by a Gaussian with the peak at $M_{I,m}=-0.23$, and the dispersion $\sigma_{RC}\approx0.2 $mag. This allows a single step determination of the distance modulus to M31 $\mu_{0,M31} = 24.471\pm 0.035 \pm 0.045 $mag (statistical plus systematic error) and the corresponding distance $R_{M31}= 784\pm 13\pm 17 kpc$. The number of red clump stars is large enough that the formal statistical error in the distance is only $\lesssim 2$%. We also correct the treatment of the local interstellar extinction by Paczy\'nski & Stanek and we obtain the Galactocentric distance modulus $\mu_{0,GC}=14.57 \pm0.04 \pm 0.04 $mag (statistical plus systematic error), and the corresponding Galactocentric distance $R_0=8.2 \pm0.15 \pm 0.15 kpc$.

Following an approach developed by Paczynski & Stanek, we derive a distance to the Large Magellanic Cloud (LMC) by comparing red clump stars from the Hipparcos catalog with the red clump stars observed in two fields in the LMC that were selected from the ongoing photometric survey of the Magellanic Clouds to lie in low-extinction regions. The use of red clump stars allows a single step determination of the distance modulus to the LMC, μ0, LMC=18.065 ± 0.031 ± 0.09 mag (statistical plus systematic error), and the corresponding distance, RLMC=41.02 ± 0.59 ± 1.74 kpc. This measurement is in excellent agreement with the recent determination by Udalski et al., also based on the red clump stars, but is ~0.4 mag smaller than the generally accepted value of μ0, LMC=18.50 ± 0.15 mag. We discuss possible reasons for this discrepancy and how it can be resolved.

We compare red clump stars with parallaxes known to better than 10% in the Hipparcos catalog and corrected for the interstellar extinction, with the OGLE red clump stars in Baade's Window also corrected for the interstellar extinction. There are $\sim 600$ and $\sim 10,000$ such stars in the two data sets, respectively. We find empirically that the average I-band magnitude of red clump stars does not depend on their intrinsic color in the range $ 0.8 < (V-I)_0 < 1.4 $. The red clump luminosity function is well represented by a gaussian with the peak at $ M_{I_0,m} = -0.26 $, and the dispersion $ \sigma _{RC} \approx 0.2 $ mag. This allows a single step determination of the distance to the galactic center and gives $ R_0 = 8.4 \pm 0.4 $ kpc. The number of red clump stars is so large that a formal statistical error is only $\sim 1%$. The local stars are relatively blue and have a small color dispersion: $ = 1.01, \sigma_{(V-I)} = 0.08$, while for the bulge stars $ = 1.22, \sigma_{(V-I)_0} = 0.14$. Presumably, the bulge population has a broader range and a higher average metallicity than the local disk population.