Effect of Terbufos (Organophosphate) on the Cadaveric Colonization Process: Implications for Postmortem Interval Calculation

2021 ◽  
Author(s):  
J T Jales ◽  
T M Barbosa ◽  
V P Soares ◽  
R A Gama
Keyword(s):  
Development Time ◽  
Accurate Method ◽  
Postmortem Interval ◽  
Dispersion Pattern ◽  
Water Control ◽  
Composition And Structure ◽  
Female Wistar Rats ◽  
Colonization Process ◽  
Pmi Estimation

Abstract The determination of necrophagous fly specie’s development time is considered an accurate method for estimating postmortem interval (PMI). However, pesticides and other chemicals can alter the flies’ life cycle, inducing errors in PMI estimation. Thus, this work aimed to evaluate the effect of different doses of Terbufos (Organophosphates) on the temporal dispersion pattern and development of immature dipterans associated with decaying rat carcasses. For this, 150 g female Wistar rats received, via gavage, 200 µl of Terbufos (5 or 10 mg/kg) or distilled water (control) and, after 30 min of administration, the animals were euthanized and distributed in suspended traps to decompose under environmental conditions. The dispersing immatures were collected daily, and their development time was monitored until the emergence of adult flies. After data analysis, it was observed that Terbufos altered 1) the temporal pattern of larval dispersion; 2) the composition and structure of the colonizing assemblage (emerged adults); 3) species’ development time, accelerating or delaying their cycle, depending on the dose used; and 4) the califorids and sarcophagids emergence rate, increasing the mortality of pupae from intoxicated carcasses. Thus, this work demonstrates experimentally that Terbufos directly influences the development of flies with forensic potential and discusses the implications for PMI estimation, which can assist in future investigative processes with suspected poisoning by this organophosphate.

Effects of Methamphetamine on the Development and Its Determination in Aldrichina grahami (Diptera: Calliphoridae)

2019 ◽  
Vol 57 (3) ◽  
pp. 691-696 ◽  
Author(s):  
Shiwen Wang ◽  
Changquan Zhang ◽  
Wei Chen ◽  
Lipin Ren ◽  
Jiang Ling ◽  
...  
Keyword(s):  
North America ◽  
Age Determination ◽  
Developmental Rate ◽  
Developmental Time ◽  
Postmortem Interval ◽  
The Mean ◽  
Forensic Investigations ◽  
Pmi Estimation

Abstract Age determination of necrophagous flies serves as an important tool for postmortem interval (PMI) estimation in forensic investigations. Drugs or toxins in cadavers may alter the developmental time of larvae, and lead to deviation in PMI estimation. Methamphetamine (MA), as one of the most abused psychostimulant drugs in Asia and North America, is often involved in forensic entomotoxicological cases. This study investigated the effects of MA (0, 45, 90, and 180 ng/mg) on the developmental rate, morphology, and survival of Aldrichina grahami (Aldrich, 1930). The results showed that 1) the developmental time to reach the pupal instar was statistically slower for the larvae reared on rabbit mince containing MA than for the control; 2) the mean length of the larvae exposed to MA concentrations was longer than those of the control; 3) the mean weight of the pupae exposed to the highest concentration of MA was significantly lighter than those of the control; 4) the GC–MS method can detect the content of MA in A. grahami immatures and empty puparia (EP).

Development of an HPLC-UV Method for Quantification of Stattic

2019 ◽  
Vol 15 (6) ◽  
pp. 568-573
Author(s):  
Soheil Sedaghat ◽  
Ommoleila Molavi ◽  
Akram Faridi ◽  
Ali Shayanfar ◽  
Mohammad Reza Rashidi
Keyword(s):  
High Performance ◽  
Accurate Method ◽  
Plasma Samples ◽  
Promising Target ◽  
Relative Standard ◽  
Dimerization Inhibitor ◽  
Oncogenic Protein ◽  
First Time ◽  
Transcription 3

Background: Signal transducer and activator of transcription 3 (STAT3), an oncogenic protein found constitutively active in many types of human malignancies, is considered to be a promising target for cancer therapy. Objective: In this study for the first time, a simple and accurate method has been developed for the determination of a STAT3 dimerization inhibitor called stattic in aqueous and plasma samples. Methods: A reverse-phase high-performance liquid chromatography (RP-HPLC) composed of C18 column as stationary phase, and the mixture of acetonitrile (60%) and water (40%) as mobile phase with a UV detection at 215 nm were applied for quantification of stattic. The developed method was validated by Food and Drug Administration (FDA) guideline. Results: The method provided a linear range between 1-40 and 2.5-40 µg mL-1 for aqueous and plasma samples, respectively, with a correlation coefficient of 0.999. The accuracy (as recovery) of the developed method was found to be between 95-105% for aqueous medium and 85-115% for plasma samples. The precision (as relative standard deviation) for aqueous and plasma samples was less than 6% and 15%, respectively. The sensitivity of the developed method based on FDA guideline was 1 µg mL-1 for aqueous and 2.5 µg mL-1 for plasma samples. Conclusion: These results show that the established method is a fast and accurate quantification for stattic in aqueous and plasma samples.

Is it necessary to calculate Young’s modulus in AFM nanoindentation experiments regarding biological samples?

2020 ◽  
Vol 12 ◽  
Author(s):  
S.V. Kontomaris ◽  
A. Malamou ◽  
A. Stylianou
Keyword(s):  
Young’S Modulus ◽  
Biological Samples ◽  
Young's Modulus ◽  
Reference Sample ◽  
Nonlinear Behavior ◽  
Accurate Method ◽  
Accurate Solution ◽  
Hertz Model ◽  
Work Done

Background: The determination of the mechanical properties of biological samples using Atomic Force Microscopy (AFM) at the nanoscale is usually performed using basic models arising from the contact mechanics theory. In particular, the Hertz model is the most frequently used theoretical tool for data processing. However, the Hertz model requires several assumptions such as homogeneous and isotropic samples and indenters with perfectly spherical or conical shapes. As it is widely known, none of these requirements are 100 % fulfilled for the case of indentation experiments at the nanoscale. As a result, significant errors arise in the Young’s modulus calculation. At the same time, an analytical model that could account complexities of soft biomaterials, such as nonlinear behavior, anisotropy, and heterogeneity, may be far-reaching. In addition, this hypothetical model would be ‘too difficult’ to be applied in real clinical activities since it would require very heavy workload and highly specialized personnel. Objective: In this paper a simple solution is provided to the aforementioned dead-end. A new approach is introduced in order to provide a simple and accurate method for the mechanical characterization at the nanoscale. Method: The ratio of the work done by the indenter on the sample of interest to the work done by the indenter on a reference sample is introduced as a new physical quantity that does not require homogeneous, isotropic samples or perfect indenters. Results: The proposed approach, not only provides an accurate solution from a physical perspective but also a simpler solution which does not require activities such as the determination of the cantilever’s spring constant and the dimensions of the AFM tip. Conclusion: The proposed, by this opinion paper, solution aims to provide a significant opportunity to overcome the existing limitations provided by Hertzian mechanics and apply AFM techniques in real clinical activities.

scholarly journals A SIMPLE AND ACCURATE METHOD FOR THE DETERMINATION OF CHLORIDE IN BIOLOGICAL FLUIDS

1941 ◽  
Vol 140 (3) ◽  
pp. 879-884
Author(s):  
Otto Schales ◽  
Selma S. Schales
Keyword(s):  
Biological Fluids ◽  
Accurate Method

A highly accurate method for determination of dissolved oxygen: Gravimetric Winkler method

2012 ◽  
Vol 741 ◽  
pp. 21-31 ◽  
Author(s):  
Irja Helm ◽  
Lauri Jalukse ◽  
Ivo Leito
Keyword(s):  
Dissolved Oxygen ◽  
Accurate Method ◽  
Winkler Method

scholarly journals Erythrocyte Antioxidative Enzymes in Experimentally Induced Osteopenia in Rats

2012 ◽  
Vol 56 (4) ◽  
pp. 669-675 ◽  
Author(s):  
Radosław P. Radzki ◽  
Marek Bieńko ◽  
Edyta Albera ◽  
Marta Kankofer
Keyword(s):  
Mineral Content ◽  
Mineral Density ◽  
Initial Body Weight ◽  
Dynamic Changes ◽  
Bone Parameters ◽  
Dynamic Relationship ◽  
Healthy Female ◽  
Female Wistar Rats ◽  
Determination Of Activity

Abstract The study aimed at the determination of dynamic relationship between mineralisation processes and antioxidative/oxidative status during the development of osteopenia. One hundred and two healthy female Wistar rats at the age of 2 months and initial body weight of 200 g were used in the experiment. The rats were divided into control (CON, n=6), sham operated (SHO, n=48), and ovariectomised (OVX, n=48) groups. Animals from SHO (n=6) and OVX (n=6) groups were sacrificed every week during 8 weeks of the experiment in order to detect dynamic changes in examined parameters. The samples were collected weekly from day 7 to day 56. The femora were examined with the use of DXA (bone mineral density) and pQCT (area, mineral content, volumetric density of trabecular and cortical part of distal femora). The pQCT scans were performed 5 mm from distal end of the tibia. The determination of activity of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) in haemolysates of erythrocytes were performed spectrophotometrically. Obtained data showed wave like changes in both enzyme activities and bone parameters and indicated the importance of the 2nd-3rd and 5th-6th week after surgery as a key moment for bone metabolism and activity of enzymatic antioxidative defence during the development of osteopenia induced by bilateral ovariectomy. The obtained results proved that alterations in activity of GSH-Px and SOD, and pQCT ahead the changes registered by DXA by 7 d.

A ratiometric electrochemical strategy for sensitive determination of Furin activity based on dual signal amplification and antifouling nanosurfaces

The Analyst ◽  
2017 ◽  
Vol 142 (22) ◽  
pp. 4215-4220 ◽  
Author(s):  
Dazhi Yao ◽  
Wenqi Zhao ◽  
Limin Zhang ◽  
Yang Tian
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cell Surface ◽  
Signal Amplification ◽  
Accurate Method ◽  
Sensitive Determination ◽  
Dual Signal Amplification

Developing a sensitive and accurate method for Furin activity is still the bottleneck for understanding the role played by Furin in cell-surface systems and even in Alzheimer's disease.

scholarly journals Structure investigations of layered soil – varved clay

2016 ◽  
Vol 48 (4) ◽  
pp. 365-375 ◽  
Author(s):  
Matylda Tankiewicz
Keyword(s):  
Mechanical Behavior ◽  
Internal Structure ◽  
Strength Properties ◽  
Layered Soil ◽  
Radiographic Images ◽  
Composition And Structure ◽  
Computed Microtomography ◽  
Structure Investigations ◽  
Varved Clay

Abstract In the paper the results of laboratory investigations of structure of layered soil are presented. They focus on varved clay that is a soil composed of two alternately arranged varves with different texture and mechanical properties. An effect of such structure is an anisotropy of the material. Due to varying conditions during its formation process the soil exhibits some irregularities in composition and structure. Due to that modelling of mechanical behavior, like strength, may not provide satisfactory results. Main purpose of the examinations is an investigation of internal structure of layered soil – varved clay – in relation to its strength anisotropy and evaluation of the suitability of the use of two different techniques to assess the soil structure. Investigated material have been taken from area near city of Bełchatów in central Poland. The examinations included investigation of particle size distribution of soil and its components, identification of lamination with use of scanning electron microscope (SEM) and computed microtomography technique (μCT). First, the texture of each varve and varved clay as a composite have been estimated. Next, the investigation of surface perpendicular to the lamination have been carried out with SEM. Pictures of varves with different magnifications are presented. Also the varves arrangement and details of layers contact area are shown. Finally, investigation of internal structure of the soil have been performed by using microtomograph. The outcome is a series of radiographic images and reconstructed 3D model of tested soil. Presented results show complexity of the structure of varved clay that affect the mechanical behavior. Determination of the structure with use of presented techniques may be helpful in examination of strength properties and proper modeling of such soil.

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