Surgical management of continuous and mixed type of OPLL in cervical spine: Experience in tertiary level hospital.

Background: Ossification of the posterior longitudinal ligament (OPLL) is a chronically progressive disease of ectopic enchondral and membranous ossification of posterior longitudinal ligament (PLL). Controversy still persists over the superiority of various surgical approaches for cervical OPLL management. Purpose: To see the efficacy of expansive laminoplasty for the management of continuous and mixed type of cervical OPLL retrospectively. Methods: Records of 20 male and 8 female aged 36-72 years (mean, 56.64 years), who underwent surgical treatment posteriorly for continuous and mixed type OPLL by laminoplasty were obtained from the year 2004 - 2020. Clinical features along with imaging studies, which included X -ray/CT /MRI, were done for the diagnosis of OPLL. Multiple variables were studied, including demographics, surgical parameters, complications and functional outcomes. Results: They were followed on an average of 59.86 ± 20.95 months (range, 24 -108 months). The average operative duration was 95 ± 15.52 min (range: 70 - 140), and the intraoperative blood loss was 199.29 ± 33.55 ml. The cervical curvature index reduced to 8.81 ± 1.96 from 11.00 ± 2.49 and the VAS score decreased from 4.25 ± 0.75 to 2.43 ± 1.40. mJOA score improved from 8.64 ± 1.03 to 13.96 ± 1.26 on the last follow-up after surgery (p < 0.01), with average recovery rate of 65.5 %. Conclusions: The management for cervical myelopathy with multilevel stenosis due to continuous and mixed type of OPLL by Laminoplasty is safe and effective.

PTSD in the Year Following Sexual Assault: A Meta-Analysis of Prospective Studies

Objective: Sexual assault is associated with higher rates of posttraumatic stress disorder (PTSD) than other traumas, and the course of PTSD may differ by trauma type. However, the course of PTSD after sexual assault has not been summarized. The aim of this meta-analysis was to identify the prevalence and severity of PTSD and changes to the average rate of recovery in the 12 months following sexual assault. Method: Authors searched four databases for prospective studies published before April 2020 and sought relevant unpublished data. Eligible studies assessed PTSD in at least 10 survivors of sexual assault in at least two time points, starting within 3 months postassault. Random effects linear-linear piecewise models were used to identify changes in average recovery rate and produce model-implied estimates of monthly point prevalence and mean symptom severity. Results: Meta-analysis of 22 unique samples ( N = 2,106) indicated that 74.58% (95% confidence interval [CI]: [67.21, 81.29]) and 41.49% (95% CI: [32.36, 50.92]) of individuals met diagnostic criteria for PTSD at the first and 12th month following sexual assault, respectively. PTSD symptom severity was 47.94% (95% CI: [41.27, 54.61]) and 29.91% (95% CI: [23.10, 36.73]) of scales’ maximum severity at the first and 12th month following sexual assault, respectively. Most symptom recovery occurred within the first 3 months following sexual assault, after which point the average rate of recovery slowed. Conclusions: Findings indicate that PTSD is common and severe following sexual assault, and the first 3 months postassault may be a critical period for natural recovery.

A Scenario-Based Management of Water Resources and Supply Systems Using a Combined System Dynamics and Compromise Programming Approach

Long-term sustainability in water supply systems is a major challenge due to water resources depletion, climate change and population growth. This paper presents a scenario-based approach for performance assessment of intervention strategies in water resources and supply systems (WRSS). A system dynamics (SD) approach is used for modelling the key WRSS components and their complex interactions with natural and human systems and is combined with a multi-criteria decision analysis for sustainability performance assessment of strategies in each scenario. The scenarios combine population growth rates with groundwater extraction limits and three intervention strategies. The methodology was demonstrated on a real-world case study in Iran. Results show scenario-based analysis can provide suitable strategies leading to long-term sustainability of water resources for each scenario imposed on the water systems. For scenarios with either no threshold or one threshold of groundwater extraction limit, the only effective strategies for sustainable groundwater preservation are those involving agricultural water demand decrease with an average recovery rate of 130% for groundwater resources while other strategies of agricultural groundwater abstraction (constant/increase rates) fail to sustainably recover groundwater resources. However, all analysed strategies can provide sustainability of water resources with an average recovery rate of 33% for groundwater resources only when scenarios with two threshold limits are in place. The impact of scenarios on groundwater conservation is quite minor for population growth rates with an average recovery rate of 11% compared to groundwater extraction limits with an average recovery rate of 79% between no threshold and two threshold limits.

Method Development and Validation of Anabasine and Nornicotine in Human Plasma by LC-MS/MS

Aim: For the Method development and validation of Anabasine and Nornicotine in human plasma LC-MS/MS technique is used. Methodology: Operated in positive electron spray ionization which removes the hardness in ions. Metoprolol is used as an internal standard. Mass analyzers are used to determine the mass to charge ratio. Liquid chromatography separates mixture components in the basis of differences in affinity for stationary and mobile phase. It removes undesired impurities. It increases reproducibility, sensitivity, robustness, detection of low-level proteins. C18 Column (Phenomenex Luna C18, 5 μm, 50*4.6mm ID) is used to for high resolution and peak area. Calibration curve is constructed with the help of linear regression. During the entire process no instability is found. Results: m/z values of Anabasine are 162.84(Q1), 134.68(Q3) and for Nornicotine are 148.90(Q1), 79.82(Q3). Back calculated curve is calculated at different concentrations from 1-1000ng/ml and their accuracy range from 97-105% for Anabasine and 93-108% for Nornicotine. In Anabasine and Nornicotine the precision and accuracy are calculated by Intra-batch and inter-batch. In the process of multi-step preparation, consider n=6 for intra-batch and n=18 for inter-batch the values obtained are between the nominal concentrations i.e., 90-110%. For each analyte the coefficients of variation are below nominal criteria <15%. For Anabasine and Nornicotine the average recovery rate is 98.3% and 94.3%.

Determination of available and carbonate antimony (Sb) in soil by Atomic Fluorescence Spectrometry

Antimony (Sb) is a toxic and potentially carcinogenic metalloid element. The toxicity of Sb in the environment strongly relies on its speciation. It is necessary to investigate the speciation and content of antimony in soil in order to understand better the real risk associated with Sb in the environment. This study developed water bath heating and soaking-AFS methods to determine the available and carbonate antimony in soil. Through analysis and mutual verification experiments in three different laboratories, the repeatability and reproducibility in the precision experiment were less than 3.44, the average recovery rate was more than 98.1%. These methods were accurate, reproducible and effective for detecting the content of available and carbonate antimony in soil.

Catalase biosensor based on the PAni/cMWCNT support for peroxide sensing

Polymeric-based composites can contribute to enhancing the detection, stability, and performance of enzymatic biosensors, due to their high structural stability, conductivity, and biocompatibility. This work presents the fabrication of a nanocomposite of polyaniline (PAni)/gold nanoparticles (AuNP)/carboxylated multiwalled carbon nanotubes (cMWCNT) as functional support for covalently linked catalase (CAT) enzyme. PAni was electropolymerized on a screen-printed carbon electrode (SPCE) and decorated with AuNP to improve charge transfer properties. CAT was bonded through amide formation using the carboxylic groups of cMWCNT, resulting in PAni/AuNP/cMWCNT/CAT biosensor. The structural and electroactive characteristics of the nanocomposite were studied by SEM, FT-IR, and cyclic voltammetry. The optimal performance was achieved after CAT immobilization over PAni/AuNP/cMWCNT/nanocomposite, showing improved analytical features such as a fast amperometric response of 1.28 s, a wide detection range from 0.01 to 6.8 mM, a correlation coefficient (R 2) of 0.9921, a low detection limit of 2.34 µM, and an average recovery rate of 99.6% when evaluated in milk samples. Additionally, the bioelectrode showed excellent selectivity and retained bioactivity after 30 days of storage. Such remarkable performance proved the synergistic effects of both the high surface area of the cMWCNT and AuNP and the inherent PAni electroactivity, yielding direct electron transfer from CAT.

Coupling Square Wave Anodic Stripping Voltammetry with Support Vector Regression to Detect the Concentration of Lead in Soil under the Interference of Copper Accurately

In this study, an effective method for accurately detecting Pb(II) concentration was developed by coupling square wave anodic stripping voltammetry (SWASV) with support vector regression (SVR) based on a bismuth-film modified electrode. The interference of different Cu2+ contents on the SWASV signals of Pb2+ was investigated, and a nonlinear relationship between Pb2+ concentration and the peak currents of Pb2+ and Cu2+ was determined. Thus, an SVR model with two inputs (i.e., peak currents of Pb2+ and Cu2+) and one output (i.e., Pb2+ concentration) was trained to quantify the above nonlinear relationship. The SWASV measurement conditions and the SVR parameters were optimized. In addition, the SVR mode, multiple linear regression model, and direct calibration mode were compared to verify the detection performance by using the determination coefficient (R2) and root-mean-square error (RMSE). Results showed that the SVR model with R2 and RMSE of the test dataset of 0.9942 and 1.1204 μg/L, respectively, had better detection accuracy than other models. Lastly, real soil samples were applied to validate the practicality and accuracy of the developed method for the detection of Pb2+ with approximately equal detection results to the atomic absorption spectroscopy method and a satisfactory average recovery rate of 98.70%. This paper provided a new method for accurately detecting the concentration of heavy metals (HMs) under the interference of non-target HMs for environmental monitoring.

Carbon nanomaterial-derived lung burden analysis using UV-Vis spectrophotometry and proteinase K digestion

Background The quantification of nanomaterials accumulated in various organs is crucial in studying their toxicity and toxicokinetics. However, some types of nanomaterials, including carbon nanomaterials (CNMs), are difficult to quantify in a biological matrix. Therefore, developing improved methodologies for quantification of CNMs in vital organs is instrumental in their continued modification and application. Results In this study, carbon black, nanodiamond, multi-walled carbon nanotube, carbon nanofiber, and graphene nanoplatelet were assembled and used as a panel of CNMs. All CNMs showed significant absorbance at 750 nm, while their bio-components showed minimal absorbance at this wavelength. Quantification of CNMs using their absorbance at 750 nm was shown to have more than 94% accuracy in all of the studied materials. Incubating proteinase K (PK) for 2 days with a mixture of lung tissue homogenates and CNMs showed an average recovery rate over 90%. The utility of this method was confirmed in a murine pharyngeal aspiration model using CNMs at 30 μg/mouse. Conclusions We developed an improved lung burden assay for CNMs with an accuracy > 94% and a recovery rate > 90% using PK digestion and UV-Vis spectrophotometry. This method can be applied to any nanomaterial with sufficient absorbance in the near-infrared band and can differentiate nanomaterials from elements in the body, as well as the soluble fraction of the nanomaterial. Furthermore, a combination of PK digestion and other instrumental analysis specific to the nanomaterial can be applied to organ burden analysis.

A Sensitive Impedimetric Aptasensor Based on Carbon Nanodots Modified Electrode for Detection of 17ß-Estradiol

A simple and sensitive aptasensor based on conductive carbon nanodots (CDs) was fabricated for the detection of 17ß-Estradiol (E2). In the present study, the hydrothermal synthesis of carbon nanodots was successfully electrodeposited on a screen-printed electrode (SPE) as a platform for immobilization of 76-mer aptamer probe. The morphology and structure of the nanomaterial were characterized by UV-visible absorption spectra, Fluorescence spectra, Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). Moreover, cyclic voltammetry and electrochemical impedance spectroscopy were used to investigate the electrochemical performance of the prepared electrodes. Subsequently, impedimetric (EIS) measurements were employed to investigate the relative impedances changes before and after E2 binding, which results in a linear relationship of E2 concentration in the range of 1.0 × 10−7 to 1.0 × 10 −12 M, with a detection limit of 0.5 × 10−12 M. Moreover, the developed biosensor showed high selectivity toward E2 and exhibited excellent discrimination against progesterone (PRG), estriol (E3) and bisphenol A (BPA), respectively. Moreover, the average recovery rate of spiked river water samples with E2 ranged from 98.2% to 103.8%, with relative standard deviations between 1.1% and 3.8%, revealing the potential application of the present biosensor for E2 detection in water samples.

Dissipation of Emamectin Benzoate Residues in Rice and Rice-Growing Environments

The experiment developed the ultra-high-performance liquid chromatography–tandem mass spectrometry (UPLC/MS/MS) method for testing emamectin benzoate, and studied the metabolism of emamectin benzoate in rice plants and rice-growing environments via application of this testing method. The dissipation curve of emamectin benzoate standard substance was good at 0.5–200 μg L−1, and its correlation coefficient was greater than 0.99. In the concentration range of 0.1–50 μg kg−1, the average recovery rate of plants, soil, and field water was 82 %–102 %, and relative standard deviation (RSD) was between 0.3 % and 15.9 %. Half-lives in rice plants and soil were 0.8–2.8 days and 1.9–3.8 days, respectively, and emamectin benzoate was not detected in rice or rice hull. The experiment showed that emamectin benzoate is harmless to human health at the concentration recommended by the manufacturer.