Polyvinylidene Fluoride-Added Ceramic Powder Composite Near-Field Electrospinned Piezoelectric Fiber-Based Low-Frequency Dynamic Sensors.

In this study, near-field electrospinning (NFES) is used to fabricate Ba x Sr1-x TiO3 (BST)/poly(vinylidene fluoride) (PVDF) piezoelectric fiber composites with excellent mechanical properties and chemical properties. BST ceramic powder is blended with PVDF solution uniformly to prepare a solution of appropriate conductance. The parameter for BST/PVDF fiber processing is based on PVDF fibers. Scanning electron microscopy, differential scanning calorimetry, microtensile testing, Fourier transform infrared spectroscopy, and electricity test of the blends of BST/PVDF fibers are incorporated. Mechanical properties of the fibers are then measured by microtensile testing. Effects of distinct ratios of Ba/Sr and the content of Ba0.7Sr0.3TiO3 ceramic powder on BST/PVDF piezoelectric fibers are discussed. Finally, BST/PVDF piezoelectric fiber composites are patterned on a poly(ethylene terephthalate) (PET)-based structure with an interdigital electrode as a BST/PVDF flexible energy harvester to capture ambient energy. The results show that the BST ceramic powder is ∼58-93 nm, and the diameters of piezoelectric fiber composites are ∼6.8-13.7 µm. The tensile strength of piezoelectric fiber composites is ∼74.92 MPa, and the Young's coefficient tensile strength is ∼3.74 GPa. Mechanical properties are 2-3 times higher than those of pure PVDF piezoelectric fibers. The maximum open-circuit voltage and closed-loop current of BST/PVDF fibers reached ∼1025 mV and ∼391 nA, respectively. The electromechanical energy conversion efficiency of the BST/PVDF energy harvester is found to be 1-2 times higher than that of the PVDF energy harvester. It is confirmed and validated that the addition of BST ceramic powder could effectively increase the piezoelectric constant of PVDF piezoelectric fibers.

Nanoparticles-mediated Brain Imaging and Disease Prognosis by Conventional as well as Modern Modal Imaging Techniques: a Comparison.

BACKGROUND: Multimodal imaging plays an important role in the diagnosis of brain disorders. Neurological disorders need to be diagnosed at an early stage for their effective treatment as later, it is very difficult to treat them. If possible, diagnosing at an early stage can be much helpful in curing the disease with less harm to the body. There is a need for advanced and multimodal imaging techniques for the same. This paper provides an overview of conventional as well as modern imaging techniques for brain diseases, specifically for tumor imaging. In this paper, different imaging modalities are discussed for tumor detection in the brain along with their advantages and disadvantages. Conjugation of two and more than two modalities provides more accurate information rather than a single modality. They can monitor and differentiate the cellular processes of normal and diseased condition with more clarity. The advent of molecular imaging, including reporter gene imaging, has opened the door of more advanced noninvasive detection of brain tumors. Due to specific optical properties, semiconducting polymer-based nanoparticles also play a pivotal role in imaging tumors. OBJECTIVE: The objective of this paper is to review nanoparticles-mediated brain imaging and disease prognosis by conventional as well as modern modal imaging techniques. CONCLUSION: We reviewed in detail various medical imaging techniques. This paper covers recent developments in detail and elaborates a possible research aspect for the readers in the field.

Tubal ligation via colpotomy or laparoscopy: a retrospective comparative study.

OBJECTIVE: To compare transvaginal with laparoscopic tubal sterilization with respect to invasiveness and outcomes. METHOD: The outcomes of 103 patients who received interval tubal sterilization were compared. Group A (n = 38) underwent the transvaginal approach, group B (n = 38) a laparoscopic approach, and group C (n = 27) underwent mini-laparotomy due to difficulties encountered in one of the other procedures. RESULTS: There were no significant differences in patient age between the groups. There was no significant difference in operative time or blood loss between groups A and B. Operative time was significantly longer in group C (120 ± 35 min) than group A (40 ± 5 min) or group B (45 ± 9 min) (p < 0.05). Blood loss was significantly greater in group C (120 ± 30 ml) than in group A (10 ± 2 ml) or group B (10 ± 1 ml) (p < 0.05). The cost of transvaginal tubal sterilization was the lowest, and that of mini-laparotomy was the highest. There was no contraception failure in any group. CONCLUSIONS: Transvaginal tubal sterilization is technically more difficult, but when correctly performed it is not associated with an increased complication rate, and is less costly than laparoscopic sterilization.