Sonographic measurement of ear length among normal fetuses of pregnant Igbo women in port Harcourt, Nigeria

Background: Fetal ear length measurement has been associated with some clinical values: sonographic marker for chromo- somal aneuploidy and for biometric estimation of fetal gestational age. Objectives: To establish a baseline reference value for fetal ear length and to assess relationship between fetal ear length and gestational age. Methods: Ear length measurements were obtained prospectively from fetuses in 551 normal singleton pregnancies of 15 to 41 weeks gestation. Normal cases were defined as normal sonographic findings during examination plus normal infant post-delivery. The relationship between gestational age (GA) in weeks and fetal ear length (FEL) in millimeters were analyzed by simple linear regression. Correlation of FEL measurements with GA, biparietal diameter (BPD), Head circumference (HC), Abdominal Circumference (AC), Femur Length (FL) and maternal age (MA) were also obtained. Results: Linear relationships were found between FEL and GA (FEL=0.872GA-2.972). There was a high correlation between FEL and GA (r = 0.837; P = .001). Good linear relationship and strong positive correlation were demonstrated between FEL and BPD, AC, HC, and FL (p<0.05). Conclusion: The result of this study provides normal baseline reference value for FEL. The study also showed good linear relationship and good correlation between FEL and fetal biometric measurements. Keywords: Fetal ear length; sonographic measurement; chromosomal aneuploidy.

Evaluation of Yogurt Quality during Storage by Fluorescence Spectroscopy

The physico-chemical parameters including pH and viscosity, and the fluorescence signal induced by fluorescent compounds presenting in yogurts such as riboflavin and porphyrin were measured during one week’s storage at room temperature when five brands of yogurt samples were exposed to ambient air. The fluorescence spectra of yogurt showed four evident emission peaks, 525 nm, 633 nm, 661 nm, and 672 nm. To quantitatively investigate the quality of yogurt during deteriorating, a calculating method of the average rate of change (ARC) was proposed to study the relative change of fluorescence intensity in the spectral range of 600 to 750 nm associated with porphyrin and chlorin compounds. During the storage, the time evolution of two ARC, pH value, and viscosity were regular. Moreover, the ARC showed a good linear relationship with pH value and viscosity of yogurt. Further, multiple linear regression (MLR) models using two ARC as independent variables were developed to verify the dependence of fluorescence signal with pH value and viscosity, which showed a good linear relationship with an R-square of more than 85% for each class of yogurt. The results demonstrate that fluorescence spectra have a great potential to predict the quality of yogurt.

A sensitive Pb2+ testing method based on aptamer-functionalized peroxidase-like 3D-flower MoS2 microspheres

We, herein, report a sensitive EC bioanalytical protocol for the detection of Pb2+ based on AuPt–MCNTs as a platform and 3D-flower MoS2–GR hybrids as signal probes. This method showed a good linear relationship between the current response and the Pb2+ concentration. It can be widely utilized for the identification of other target molecules.

Investigating the Interaction of Ninhydrin with Amino Acids and Polypeptide

Ninhydrin chromogenic reactions are widely used to analyze and characterize amino acids, peptides, and proteins. In this study, the spectroscopy behavior of ninhydrin reaction with mercapto amino acid and polypeptide has been investigated. The maximum absorption wavelength of glutathione reaction with ninhydrin was 568 nm; the maximum absorption wavelength of cysteine reaction with ninhydrin was 457 nm. Under the optimized wavelength condition, glutathione and cysteine in the certain concentration range exhibt good linear relationship and low detection limit.

Determination of Boron in Water Samples by the Spectrophotometric Curcumin Method

The boron concentrations in water samples from the Yellow River and a reservoir were measured by the spectrophotometric curcumin method. Results show that there is a good linear relationship between the absorbance and the concentration (R2=0.9991). The sensitivity of this method was 0.029 µg, and the precision is 2.05%~5.41%. For different treatments of solutions, the recovery of added boron was in the range of 96.3 to 106.2%. This method is sensitive, accurate, reproducible and easy to be operated.

Carbon Nanoparticle Spectrophotometric Determination of Glucose

In the presence of NaOH, glucose hydrolyze and polymerize to generate yellow carbon nanoparticles that had an absorption peak at 336 nm. Under the selected conditions, result showed the concentration of glucose have a good linear relationship between absorbance value and glucose concentration in the range of 0.0005-0.060 mol/L. This method has been used for the assay of glucose injection sample, with simplicity, rapidity, and accuracy.

The Soil Base Bearing Capacity Relevance Research in the Highway Overhaul Decision-Making

Based on theexamples works of the road site excavation pits channels and supplemented by road non-destructive testing methods, this paper mainly adopts the road performance of the structural layers , main site designated point FWD test, soil base DCP test and soil base structure bearing capacity correlation. The results show that the existing common road on FWD detection inverse soil base modulus has a good linear relationship with soil base DCP measured modulus, in addition, measured soil base modulus with moisture content of the soil base also have a good linear relationship, but the three correlation does not comply with the actual situation of the road. Thus, before the decision making of the highway overhaul conservation , old Road usage evaluation, the road of non-destructive testing, the excavation pits survey and structural layers indicators detection are very necessary and effective methods.

Intact Loess Structural Loss Parameter in Humidification Process

Based on soil structural view, the mechanism of loess structure is analyzed in humidification process. The concept of the loess structure loss is proposed.And quantitatively parameter described the loess structure loss is set up, that is structure loss parameter. And then the influence laws of humidification and loading on loess structure loss are discussed. The results show that structure loss parameters is increasing with the increase of the humidification water content. The moistening collapsibility has a good linear relationship with loess structure loss parameters.

Determination of Chitosan Oligosaccharide Content by Acetylacetone Spectrophotometry Method

Objective: To establish a common method to detect the content of chitosan oligosaccharide. Methods: Chitosan oligosaccharide was hydrolyzed completely by concentrated hydrochloric acid, and the solution was regulated into neutral with NaOH. Then, determined the absorbance in 525nm, and substituted into the regression equation to determine the results. Results: The results showed there was a good linear relationship when the concentration of chitosan oligosaccharide ranged from 0.02 mg/mL to 0.12 mg/mL, r2 = 0.999. The average recovery of chitosan oligosaccharide samples was 99.25%. Conclusion: The method is sensitive, accurate and simple. It is applied to determine of the content of chitosan oligosaccharide.

Research on the Physical Characteristics in Maize Deep-Bed Drying Process

In order to investigate the static pressure loss of the maize deep-bed drying related to the ratio of air flux to grain mass, the experiments based on the theory of thermal engineering and deep-bed drying were engaged in. These experiments conducted on the ventilation test stand indicate the relationship between static pressure loss, depth of the bed, ventilative dimensions and the ratio of air flux to grain mass. The investigation results that during the drying, the static pressure loss increases related to the increased ratio of air flux to grain mass with the constant bed depth. The good linear relationship between the static pressure loss and ventilative dimensions was indicated. With the control of the constant ventilative dimensions, the static pressure loss increases related to the decreased ratio of air flux to grain mass and it will dramatically increased when the ratio of air flux to grain mass is small enough. To reduce the static pressure loss, enlarging the ventilative dimensions, reducing the thickness of the drying layer and reducing the speed of the wind will be the proper methods.