RESUMEN
Fluorescent and colorimetric chemosensors for selective detection of various biologically important analytes have been widely applied in different areas such as biology, physiology, pharmacology, and environmental sciences. The research area based on fluorescent chemosensors has been in existence for about 150 years with the development of large number of fluorescent chemosensors for selective detection of cations as metal ions, anions, reactive species, neutral molecules and different gases etc. Despite the progress made in this field, several problems and challenges still exist. The most important part of sensing is limit of detection (LOD) which is the lowest concentration that can be measured (detected) with statistical significance by means of a given analytical procedure. Although there are so many reports available for detection of millimolar to micromolar range but the development of chemosensors for the detection of analytes in nanomolar range is still a challenging task. Therefore, in our current review we have focused the history and a general overview of the development in the research of fluorescent sensors for selective detection of various analytes at nanomolar level only. The basic principles involved in the design of chemosensors for specific analytes, binding mode, photophysical properties and various directions are also covered here. Summary of physiochemical properties, mechanistic view and type of different chemosensors has been demonstrated concisely in the tabular forms.
RESUMEN
At present days osteosynthesis modalities for avian fracture management are inadequate. External coaptation is the most practiced method however, specialized clinics have started introducing intramedullary pinning, external skeletal fixation with tie-in-fixation for fracture immobilization. Magnesium (Mg) based biomaterials are trustable developments in the field of orthopedics compared to their permanent stainless steel counterparts concerning long term adverse reaction. Mg implants are becoming promising for their use as intramedullary accessories because they are bioresorbable with high strength-weight ratio and the similarities in density and elastic modulus to the natural bones. However, their severe biodegradation trait restricts frequent use as load-bearing orthopedic implants. In this study, the biocompatibility and biodegradability of Mg based intramedullary cylindrical spacers (2.4 mm diameter × 8 mm height) reinforced with 0, 5, 15 wt% of hydroxyapatite (HA, Ca10 (PO4 )6 (OH)2 ) were evaluated in 18 Uttara-fowl birds. Clinical, radiological (from immediate postoperative days till 24th week), biochemical (first three postoperative weeks) and histopathological study of test bone were carried out to evaluate implant degradation and osteocompatibility. Biodegradation of Mg-3Zn/0HA and Mg-3Zn/15HA initiated a bit earlier at second week of implantation, while that of Mg-3Zn/5HA at 3-fourth week, and found biocompatible and biodegradable with no observable clinical and histopathological changes.
