A novel anatomical locked medial femoral condyle plate: a biomechanical study

BACKGROUND

Fixation with a distal lateral femoral plate is a standard approach in treating osteoporotic or comminuted supracondylar femur fractures. However, in clinical practice, this method may prove inadequate, necessitating the application of a plate on the medial side of the distal femur. The aim of this study is to perform a biomechanical evaluation of the newly manufactured anatomically locked plate applied to the distal medial femoral condyle.

MATERIALS AND METHODS

The plate underwent 2 biomechanical tests by simulating an AO/OTA 33A3 type supracondylar fracture model on synthetic femur bones. The samples were divided into three groups. Fracture fixations were carried out on the medial side using the distal femur medial anatomical locking plate (DFMALP) in group A samples, on the lateral side using the distal femur lateral anatomical locking plate in group B samples, and on both sides in group C samples.

RESULTS

In the axial compression test, stability was preserved 23% more in group C than in group B. During the cyclic axial compression test, total displacement was 21% less in group C than in group B. Group A was collapsed at early cycle degrees.

CONCLUSION

In our study, it was observed that the application of DFMALP in conjunction with the lateral plate in AO/OTA 33A3 fragmented supracondylar femur fractures significantly enhanced biomechanical fracture stability.

LEVEL OF EVIDENCE

This is a Level 2 prospective, randomized controlled study.

Structures and optical properties of zinc oxide nanoclusters: a combined experimental and theoretical approach

CONTEXT

In this study, theoretical and experimental analysis of the electrical, optical, and structural properties of a wurtzite-like zinc oxide (ZnO) nanostructure has been done. To investigate how quantum confinement affects the optical characteristics, two distinct ZnO clusters in nanowire structures have been investigated. The [(ZnO)₅₅(H₂O)₄] system's HOMO-LUMO band gap (BG) was calculated to be 2.99 eV, which is quite close to the experimental measurement. It was found that the BG decreases with the increase in the number of atoms in the cluster in connection with the quantum confinement in nanoclusters. In addition, the lowest excitation energy in TD-DFT calculations of the identical system is in fairly good agreement with the experimental value with a difference of 0.1 eV. We conclude that the CAM-B3LYP functional has highly successful in reproducing the experimental data reported in the present study and previously reported experimental data.

METHODS

The geometrical optimization of two different sizes of ZnO clusters ([(ZnO)25(H2O)4] and [ZnO)55(H2O)4]) was performed using the CAM-B3LYP functional with no symmetry constraints applied in the gas phase. LANL2DZ basis sets were used for the Zinc (Zn) atom and 6-31G* basis sets for the O and H atoms. To determine their optical and electronic properties, excited state calculations of the pre-optimized structures were performed using the Time-Dependent DFT (TD-DFT) method. Multiwfn, Gaussum 3.0, and GaussView 5.0 programs were used to visualize the results.

Controlling of dielectrical properties of hydroxyapatite by ethylenediamine tetraacetic acid (EDTA) for bone healing applications

The hydroxyapatite (HAp) samples in the presence of various amounts of ethylenediamine tetraacetic acid (EDTA) were prepared by sol-gel method. The effects of EDTA on the crystallinity, phase structure, chemical, micro-structural and dielectric properties of HAp samples were investigated. With the addition of EDTA, the average crystallite size of the HAp samples is gradually decreased from 30 to 22 nm and the crystallinity is in the range of 65-71%. The values of the lattice parameters (a and c) and volume of the unit cell are decreased by stages with the addition of EDTA. The dielectric parameters such as relative permittivity, dielectric loss and relaxation time are affected by the adding of EDTA. The alternating current conductivity of the as-synthesized hydroxyapatites increases with the increasing frequency and obeys the universal power law behavior. The HAp samples exhibit a non-Debye relaxation mechanism. The obtained results that the dielectrical parameters of the HAp sample can be controlled by EDTA.

The investigation of some bioactive compounds and antioxidant properties of hawthorn (Crataegus monogyna subsp. monogyna Jacq)

Aim:

The antioxidant and pharmacological effects of hawthorn have mainly been attributed to the polyphenolic contents. The aim of this research is to determine some bioactive compounds and antioxidant properties of hawthorn aqueous and ethanol extracts of leaves, flowers, and ripened fruits.

Materials and Methods:

For this purpose, antioxidant activities of extracts were assessed on DPPH•, ABTS•+, superoxide scavenging, reducing power and ferrous metal chelating activity assays and phenolic content of extracts was determined by Folin—Cioacalteu’s reagent.

Results:

The flavonoids including rutin, apigenin, myricetin, quercetin, naringenin and kaempferol, were identified by high-performance liquid chromatography in the hawthorn extract.

Conclusion:

It was observed the aqueous and ethanol extracts of Crataegus monogyna subsp. monogyna fruits showed the highest activity in reducing power and metal chelating activity assays. In addition, it was determined that the aqueous flower extract showed higher flavonoid content than aqueous leaves extract. The antioxidant and pharmacological effects of hawthorn have mainly been attributed to the polyphenolic contents.

Resveratrol (trans-3,4',5-trihydroxystilbene) decreases lipid peroxidation level and protects antioxidant capacity in sera and erythrocytes of old female Wistar rats induced by the kidney carcinogen potassium bromate

Resveratrol is a natural polyphenolic compound and it is found in number of edible plants, especially grapes and peanuts, has been shown to have anti-inflammatory, anti-oxidant, anti-tumor and anti-platelet activities. The aim of the study was to examine the effects of resveratrol on the level of malondialdehyde (MDA), homocysteine, cholesterol, GSH, GSSG and lipophylic vitamins in serum and erythrocytes of old female Wistar rats induced by the kidney carcinogen potassium bromate (KBrO(3)). In the study, total 30-old female Wistar rats were used, and the rats were randomly divided into three groups. The first group was used as a control, the second group KBrO(3) group, and third group R+KBrO(3). Rats in KBrO(3) and R+KBrO(3) groups were injected intraperitoneally a single dose KBrO(3) (80mg/kg) in physiologic saline buffer. After 2days, those in R+KBrO(3) group were intraperitoneally injected with resveratrol (33mg/kg) four times per week, and physiological saline was injected to control group rats. All the analysis was performed fully automatic with high performance liquid chromatography equipment. The results indicate that serum cholesterol level in the R+KBrO(3) group was higher than the control group (p<0.05), and level of the cholesterol in erythrocytes membranes was lower in the same group (p<0.01). The MDA level in serum and erythrocytes of the R+KBrO(3) were lower than the control and KBrO(3) groups (p<0.01). However, the MDA level in erythrocytes of the KBrO(3) group was high compared to the control group (p<0.05). Homocysteine and δ-tocopherol levels in serum of the R+KBrO(3) group were lower than the control group (p<0.05, p<0.001). α-Tocopherol level in serum and erythrocytes of the KBrO(3) group was lower than the control group (p<0.05), whereas its level was not found to differ between the control and R+KBrO(3) groups. GSH and GSSG levels in the KBrO(3) group of erythrocytes were higher than control group (p<0.05, p<0.01), however the ratio GSH/GSSG in the same group was lower than control group. In conclusion, our results confirm that the lipid peroxidation formation in serum and erythrocytes of old female Wistar rats by induced the KBrO(3) is prevented by the resveratrol. It was observed that the antioxidant capacity of erythrocytes was protected by resveratrol.