Determination of the crystalline size of hexagonal La1-xSrxMnO3 (x = 0.3) nanoparticles from X-ray diffraction - a comparative study.

The electronic, magnetic, optical and elastic properties of nanomaterials are governed partially by the crystallite size and crystal defects. Here, the crystalline size of hexagonal La1-xSrxMnO3 (x = 0.3) nanoparticles was determined using various methods. Single-phase La0.7Sr0.3MnO3 nanopowders were produced after 10 h of milling in a commercial high-energy SPEX 8000D shaker mill, and then they were heated at 700 °C and 800 °C to study the effect of calcined temperature on the crystallization of nanoparticles. The modified Scherrer, Williamson-Hall, size-strain, and Halder-Wagner methods were used to determine the crystallite sizes and the elastic properties, such as intrinsic strain, stress, and energy density, from the X-ray diffraction peak broadening analysis. The obtained results were then compared with one another. The difference in crystallite sizes calculated from the different methods was due to the different techniques.

A cross-sectional study of MIS TLIF in treatment of spondylolisthesis: initial good results from 92 Vietnamese patients.

Minimally invasive transforaminal lumbar interbody fusion has proven effectiveness in treating spondylolisthesis, but there were few reports applying the technique from scarce resourcing developing countries. In this study, the authors report the results and share our experience of minimally invasive spinal transforaminal lumbar interbody fusion in spondylolisthesis treatment in Vietnamese patients. Materials and methods: In this study, the authors enroled 92 patients diagnosed with single-level, grade I or grade II lumbar spondylolisthesis from January 2019 to October 2022. Results: The median age in our study was 47.79±12.61 (range 15-75), the male/female ratio was 1/2.3. The mean disease duration was 28.57 months. Conventional X-ray images showed that there were 74 patients (80.43%) with spondylolisthesis grade I, 18 patients (19.57%) with grade II. Spondylolisthesis occured mainly in L4-L5 with 53 patients (57.61%). The isthmic sign was recorded in 16 patients (31.4%). The mean blood loss was 149.46 ml. Patients walked on average of 3.22 days after surgery. VAS score reduced significantly in both back and leg. Spinal function improved significantly with a preoperative Owestry Disability Index of 48.18% decrease to 15.18% 12 months after surgery. The surgical results were good and excellent at 95.00% after 12 months of surgery according to Macnab scale. The fusion rate reached 97.50%. Conclusions: The results of this Macnab's classification study show that minimally invasive spinal transforaminal lumbar interbody fusion is an effective treatment for spondylolisthesis with less pain, less blood loss after surgery, and high fusion rate.

Multifunctional nanocarriers of Fe3O4@PLA-PEG/curcumin for MRI, magnetic hyperthermia and drug delivery.

Background: Despite medicinal advances, cancer is still a big problem requiring better diagnostic and treatment tools. Magnetic nanoparticle (MNP)-based nanosystems for multiple-purpose applications were developed for these unmet needs. Methods: This study fabricated novel trifunctional MNPs of Fe3O4@PLA-PEG for drug release, MRI and magnetic fluid hyperthermia. Result: The MNPs provided a significant loading of curcumin (∼11%) with controllable release ability, a high specific absorption rate of 82.2 W/g and significantly increased transverse relaxivity (r2 = 364.75 mM-1 s-1). The in vivo study confirmed that the MNPs enhanced MRI contrast in tumor observation and low-field magnetic fluid hyperthermia could effectively reduce the tumor size in mice bearing sarcoma 180. Conclusion: The nanocarrier has potential for drug release, cancer treatment monitoring and therapy.

In this study, the authors designed and fabricated novel magnetic trifunctional nanoparticles of Fe₃O₄@PLA-PEG. The 8.5 nm Fe₃O₄ core was covered with the polymeric matrix of PLA-PEG to encapsulate an anticancer agent of curcumin at a content of about 11%. Curcumin release from the nanoparticles (NPs) could be controlled by applying a remote alternating magnetic field. The NPs enhanced MRI contrast, which allowed the authors to better distinguish the tumor and surroundings in MR images, which would help monitor treatment. The heat that NPs generated when applied to a field at low intensity could effectively reduce the tumor size in mice bearing sarcoma 180. The nanocarrier, therefore, has potential for cancer treatment monitoring and drug release conjuvant with magnetic hyperthermia therapy.

The Role of Anisotropy in Distinguishing Domination of Néel or Brownian Relaxation Contribution to Magnetic Inductive Heating: Orientations for Biomedical Applications.

Magnetic inductive heating (MIH) has been a topic of great interest because of its potential applications, especially in biomedicine. In this paper, the parameters characteristic for magnetic inductive heating power including maximum specific loss power (SLPmax), optimal nanoparticle diameter (Dc) and its width (ΔDc) are considered as being dependent on magnetic nanoparticle anisotropy (K). The calculated results suggest 3 different Néel-domination (N), overlapped Néel/Brownian (NB), and Brownian-domination (B) regions. The transition from NB- to B-region changes abruptly around critical anisotropy Kc. For magnetic nanoparticles with low K (K < Kc), the feature of SLP peaks is determined by a high value of Dc and small ΔDc while those of the high K (K > Kc) are opposite. The decreases of the SLPmax when increasing polydispersity and viscosity are characterized by different rates of d(SLPmax)/dσ and d(SLPmax)/dη depending on each domination region. The critical anisotropy Kc varies with the frequency of an alternating magnetic field. A possibility to improve heating power via increasing anisotropy is analyzed and deduced for Fe3O4 magnetic nanoparticles. For MIH application, the monodispersity requirement for magnetic nanoparticles in the B-region is less stringent, while materials in the N- and/or NB-regions are much more favorable in high viscous media. Experimental results on viscosity dependence of SLP for CoFe2O4 and MnFe2O4 ferrofluids are in good agreement with the calculations. These results indicated that magnetic nanoparticles in the N- and/or NB-regions are in general better for application in elevated viscosity media.

Ultrasensitive biosensors based on waveguide-coupled long-range surface plasmon resonance (WC-LRSPR) for enhanced fluorescence spectroscopy.

We investigated the coupling phenomenon between plasmonic resonance and waveguide modes through theoretical and experimental parametric analyses on the bimetallic waveguide-coupled long-range surface plasmon resonance (Bi-WCLRSPR) structure. The calculation results indicated that the multi-plasmonic coupling gives rise to the enhanced depth-to-width ratio of the reflection dip compared to that of LRSPR excited using a single set of Ag and Teflon. The optimized thickness of Ag(40 nm)/Teflon(700 nm)/Ag(5 nm)/Au(5 nm) was obtained and generated the highest plasmon intensity enhancement, which was 2.38 folds in comparison to the conventional bimetallic surface plasmon resonance (SPR) configuration (Ag/Au). 17ß-Estradiol was used in the fluorescence enhancement experiment by the reflection geometry-based system, wherein the excitation light source was on the side of a WC-LRSPR chip opposite to that of the light detection unit. The phenomenon of surface plasmon-couple emission (SPCE) depends on the number of 17ß-estradiol molecule promoters from female sex steroid hormones, which demonstrated a limit of detection (LOD) of 2 pg mL-1 and 1.47-fold fluorescence improvement as compared to the non-coated material on the surface of pristine glass. This enhanced WC-LRSPR can readily find application in fluorescence escalation needed in cases where a weak fluorescence signal is predicted, such as the small volume of liquid containing fluorescent dyes in biological diagnosis.