Bio-Molecular Applications of Recent Developments in Optical Tweezers.

In the past three decades, the ability to optically manipulate biomolecules has spurred a new era of medical and biophysical research. Optical tweezers (OT) have enabled experimenters to trap, sort, and probe cells, as well as discern the structural dynamics of proteins and nucleic acids at single molecule level. The steady improvement in OT's resolving power has progressively pushed the envelope of their applications; there are, however, some inherent limitations that are prompting researchers to look for alternatives to the conventional techniques. To begin with, OT are restricted by their one-dimensional approach, which makes it difficult to conjure an exhaustive three-dimensional picture of biological systems. The high-intensity trapping laser can damage biological samples, a fact that restricts the feasibility of in vivo applications. Finally, direct manipulation of biological matter at nanometer scale remains a significant challenge for conventional OT. A significant amount of literature has been dedicated in the last 10 years to address the aforementioned shortcomings. Innovations in laser technology and advances in various other spheres of applied physics have been capitalized upon to evolve the next generation OT systems. In this review, we elucidate a few of these developments, with particular focus on their biological applications. The manipulation of nanoscopic objects has been achieved by means of plasmonic optical tweezers (POT), which utilize localized surface plasmons to generate optical traps with enhanced trapping potential, and photonic crystal optical tweezers (PhC OT), which attain the same goal by employing different photonic crystal geometries. Femtosecond optical tweezers (fs OT), constructed by replacing the continuous wave (cw) laser source with a femtosecond laser, promise to greatly reduce the damage to living samples. Finally, one way to transcend the one-dimensional nature of the data gained by OT is to couple them to the other large family of single molecule tools, i.e., fluorescence-based imaging techniques. We discuss the distinct advantages of the aforementioned techniques as well as the alternative experimental perspective they provide in comparison to conventional OT.

Impact of HIGH BMI on Pregnancy: Maternal and Foetal Outcome.

AIM AND OBJECTIVES: To review the effects of obesity (BMI > 30) on antepartum risk/intrapartum risk. To study neonatal outcome of pregnant women with raised BMI. MATERIAL METHOD: BMI of 500 pregnant women booked before 12 weeks calculated and categorised as normal, overweight, obese and morbidly obese at GMCH, Aurangabad. Pregnant women with systemic disease and previous LSCS were excluded. Antepartum, intrapartum and neonatal variables were studied, and statistical analysis was carried out. RESULTS: Antepartum variables: prolonged pregnancy (<0.05), severe PIH (<0.05), PPROM (<0.05), gestational DM (<0.05) and anaemia (<0.05) are strongly associated with raised BMI, whereas abortion (>0.05), oligohydramnios (>0.05), UTI (>0.05) and abruption (>0.05) are not associated with raised BMI. Postpartum variables: PPH (<0.05), pyrexia (<0.05), prolonged hospital stay (<0.05) and lactational dysfunction (<0.05) are strongly associated with raised BMI, whereas UTI (>0.05), thrombophlebitis (>0.05) and endometritis (>0.05) are not associated with raised BMI. BMI Neonatal outcome: IUGR (<0.05), preterm (<0.05), postterm (<0.05), LBW (<0.05) and macrosomia (>0.05) are strongly associated with raised BMI, whereas stillbirth (>0.05), intubation (>0.05), RDS (>0.05) and baby died within 24 (>0.05) are not associated with raised BMI. CONCLUSIONS: Overweight and obesity are risk factors for AP/IP/PP complication.

Enantioselective α-benzoyloxylation of ketones promoted by primary amine catalyst.

A mixture of 9-amino-(9-deoxy)epi-dihydroquinidine and salicylic acid was able to promote the direct reaction of various cyclohexanones with dibenzoyl peroxide, thus affording the corresponding protected α-hydroxy carbonyl compounds in high yield and enantioselectivity. Interestingly the same catalytic salt was found to be active when 1-indanones derivatives were directly employed in the reaction with dibenzoyl peroxide furnishing chiral 1-oxo-2,3-dihydro-1H-inden-2-yl benzoates in high yields and enantioselectivity. Furthermore their treatment with NaBH(4) gives easy access to the corresponding enantioenriched 1,2-diols in high yields and without any loss of stereoselectivity.