Y-family DNA polymerases play a crucial role in translesion DNA synthesis. Here, we have characterized the binding kinetics and conformational dynamics of the Y-family polymerase Sulfolobus ...solfataricus P2 DNA polymerase IV (Dpo4) using single-molecule fluorescence. We find that in the absence of dNTPs, the binary complex shuttles between two different conformations within ∼1 s. These data are consistent with prior crystal structures in which the nucleotide binding site is either occupied by the terminal base pair (preinsertion conformation) or empty following Dpo4 translocation by 1 base pair (insertion conformation). Most interestingly, on dNTP binding, only the insertion conformation is observed and the correct dNTP stabilizes this complex compared with the binary complex, whereas incorrect dNTPs destabilize it. However, if the n+1 template base is complementary to the incoming dNTP, a structure consistent with a misaligned template conformation is observed, in which the template base at the n position loops out. This structure provides evidence for a Dpo4 mutagenesis pathway involving a transient misalignment mechanism.
This study aimed to study the coactivation patterns of the hamstring and quadriceps muscle groups during submaximal strength exercises commonly used in injury prevention in soccer without the use of ...maximum voluntary isometric contraction testing. This was used to compare: (i) the inter-limb differences in muscle activation; (ii) the intra-muscular group activation pattern and (iii) the activation pattern during different phases of the exercise. Muscle activation was recorded by surface electromyography in 19 elite, male, youth soccer players. Participants performed the following: Bulgarian squat, lunge and squat. Electrical activity was recorded for the rectus femoris, vastus medialis, vastus lateralis, biceps femoris and semitendinosus. No significant inter-limb differences were found (F1, 13 = 619; p = 0.82; η2 = 0.045). Significant differences were found in the muscle activation between individual muscles within the quadriceps and hamstrings muscle group for each of the exercises: Bulgarian squat (F1,18 = 331: p < 0.001; η2 = 0.80), lunge (F4,72 = 114.5; p < 0.001; η2 = 0.86) and squat (F1,16 = 247.31; p < 0.001; η2 = 0.93). Differences were found between the different phases of each of the exercises (F2,26 = 52.27; p = 0.02; η2 = 0.80). The existence of an activation pattern of each of the muscles in the three proposed exercises could be used for muscle assessment and as a tool for reconditioning post-injury.
Objectives We evaluated studies that used the World Health Organization’s (WHO) AirQ and AirQ+ tools for air pollution (AP) health risk assessment (HRA) and provided best practice suggestions for ...future assessments. Methods We performed a comprehensive review of studies using WHO’s AirQ and AirQ+ tools, searching several databases for relevant articles, reports, and theses from inception to Dec 31, 2022. Results We identified 286 studies that met our criteria. The studies were conducted in 69 countries, with most (57%) in Iran, followed by Italy and India (∼8% each). We found that many studies inadequately report air pollution exposure data, its quality, and validity. The decisions concerning the analysed population size, health outcomes of interest, baseline incidence, concentration-response functions, relative risk values, and counterfactual values are often not justified, sufficiently. Many studies lack an uncertainty assessment. Conclusion Our review found a number of common shortcomings in the published assessments. We suggest better practices and urge future studies to focus on the quality of input data, its reporting, and associated uncertainties.
Gross Anatomy learning requires Three Dimensional (3D) structural visualization in order to facilitate spatial relation and structural organization understanding. This educational process ‐ when ...related to the use of cadavers ‐ has been limited due to the difficulties in acquiring specimens and their reduced shelf life. Synthetic models offer a solution to said issues, in spite of not showing possible anatomical variations.
Multiple anatomical techniques have been developed to diminish preservation drawbacks. Among these, polymer corrosion casting (CC) permits the repletion of multiple ducts of an organ, later on, corroded by acid or alkali solutions. Polyester, Epoxy and Acrylic resins are the most widely used rigid polymers for CC due to their polymerized characteristics.
This technique has been widely used for education but the final polymeric matrix exhibit several disadvantages like use‐related deterioration due to fragility. However, the mechanical characteristics of the polymers have not been described when casted under an Anatomy Laboratory protocol and not using industrial processes.
Our aim was to determine the mechanical characteristics of a rigid polyester resin (RPR) as used for CC and to compare them when using a flexible polyester resin (FPR) as an additive or the FPR by itself. FPR was used to aggregate plastic properties to the RPR, in concentrations of 10% and 20% Weight/Weight (W/W).
Multiple standard tests were carried out to characterize the resins mechanically. Tensile and three‐point bending tests were performed with an Instron Machine 3367, and impact tests with a 43‐1TMI impact tester. Each test followed the ASTM standard methods D790, D689 and D256 respectively.
Mechanical properties such as modulus of elasticity (Young Modulus), maximum strength and ultimate strength were obtained from tension tests. Flexural modulus, maximum flexural strength, maximum deflection and maximum flexural strain were obtained by three‐point bending tests while impact energy was acquired from Impact tests.
Polymer behavior showed a remarkable correlation to FPR concentration when used as an additive for RPR, increasing significantly the plastic properties of the polymer. Under tension, the major Modulus of Elasticity (1,28 ± 0,40 GPa) was visible at low FPR ratios, in contrast with the FPR alone which presented an average of 16,98 ± 1,24 MPa. This tendency is supported by the elongation at rupture results which increased significantly from 3,20 ± 2,59% for 10% FPR/RPR to 107,19 ± 13,6% for FPR alone. On the other hand, three‐point bending exhibited a similar correlation reducing the flexural modulus by 1.87 times and the maximum flexural strength 2.04 times. Impact test allows to corroborate that FPR at 10% is more fragile than FPR alone with an Impact energy of 0,062 ± 0,006 and 1,32 ± 0,24 J/cm respectively.
In comparison, RPR alone results presented a Modulus of Elasticity of 1,11 ± 0,14 GPa, an elongation at rupture of 4,73 ± 1,43%, a flexural modulus of 2,35 ± 0,37 GPa, a maximum flexural strength of 74,15 ± 17,49 MPa and an impact energy of 0,055 ± 0,005 J/cm.
Our results not only demonstrate that using additives to aggregate plastic properties to a RPR increase its mechanical resistance to rupture but also provides important information about the mechanical properties of RPR and FPR at the time of selecting a polymeric polyester‐based formulation to preserve any specimen through CC.
This is from the Experimental Biology 2018 Meeting. There is no full text article associated with this published in The FASEB Journal.
Highlights ► Pneumonia, meningitis and bacteremia account for 7500 deaths in adults in Colombia. ► Most of the burden of pneumonia and bacteremia is due to premature mortality, while in meningitis ...long-term disability is more relevant. ► Including disability and premature death, these pneumococcal diseases represent 54 thousand disability-adjusted life years (DALYs) lost. ► The burden of pneumococcal disease in adults in Colombia is similar to that of epilepsy or schizophrenia.
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