Hierarchical self-assembling and helical structure in focal conic domains in meniscus of ferroelectric liquid crystal.

We investigate experimentally the formation of focal conic domains of the ferroelectric phase of a liquid crystal, chiral smectic C (SmC^{*}), in the meniscus geometry. The meniscus geometry is formed in the gap between two glass plates which are placed on a common substrate. This gap is called here a physical cavity.

Technological advancements in bio-recognition using liquid crystals: Techniques, applications, and performance.

The application of liquid crystal (LC) materials has undergone a modern-day renaissance from its classical use in electronics industry as display devices to new-fangled techniques for optically detecting biological and chemical analytes. This review article deals with the emergence of LC materials as invaluable material for their use as label-free sensing elements in the development of optical, electro-optical and electrochemical biosensors. The property of LC molecules to change their orientation on perturbation by any external stimuli or on interaction with bioanalytes or chemical species has been utilized by many researches for the fabrication of high sensitive LC-biosensors.

Correlation between alignment geometries and memory effect in a surface-stabilized ferroelectric liquid crystal.

Memory effect in weakly aligned surface stabilized ferroelectric liquid crystal (SSFLC) material has been investigated by electro-optical and dielectric spectroscopy in three configurations of alignment: antiparallel, 90^{∘} twisted, and unaligned planar samples. It has been observed that two types of molecular dynamics exist in antiparallel rubbed cell in which memory effect is observed for longer duration than in other samples. One dielectric relaxation process is near the surface of the electrode and a second is in the bulk of the SSFLC.

Properties of chitin and chitosan extracted from silkworm pupae and egg shells.

Chitin and chitosan from silkworm pupae and egg shells show distinct properties with excellent antimicrobial properties and cytocompatiblity. Spent silkworm pupae and hatched egg shells are discarded as waste but contain valuable carbohydrates, proteins and lipids. Chitosan has excellent antimicrobial properties and is widely used for food, medical and biotechnological applications.

Collective dielectric processes at the transition temperature of the Sm-C^{*} and Sm-A^{*} phase in a ferroelectric liquid crystal.

An anomalous dielectric relaxation process, called the partially unwound helical mode (p-UHM), is a collective dielectric process apart from the well known Goldstone and soft mode process; it is studied in the smectic C^{*} (Sm-C^{*}) phase and at the transition temperature of the Sm-C^{*}-Sm-A^{*} phase in the ferroelectric liquid crystal (FLC) material. To avoid the surface effect, a thick cell of 40 μm thickness was prepared with highly rubbed surfaces of the ITO substrates. It has been observed that the dielectric properties in Sm-C^{*} and at the T_{c} temperature are dominated by the p-UHM process which is dependent on an applied oscillating field in the Sm-C^{*} phase.

Interfacial behavior of confined mesogens at smectic-C*-water boundary.

In this paper, we have investigated the behavior of mesogens at smectic-C*-water interface confined in a liquid crystal (LC) cell with interfacial geometry. Polarized optical microscopy was used to probe the appearance of various smectic-C* domain patterns at water interface owing to the reorientation of mesogens. The undulated stripe domains observed at the air interface of smectic-C* meniscus vanished as the water entered into the smectic layers and focal conical domain patterns appeared at smectic-C*-water boundary.

Langmuir-Blodgett Nanoassemblies of the MoS-Au Composite at the Air-Water Interface for Dengue Detection.

We report Langmuir-Blodgett (LB) films of molybdenum disulphide (MoS) and gold nanoparticles (AuNP) composite being utilized as a biosensing platform for dengue detection. The LB films of the MoS-AuNP composite have been transferred from the air-water interface to the indium tin oxide-coated glass substrate under optimized conditions. Further, antibodies specific to dengue NS1 antigen were immobilized onto these LB films.

Dielectric relaxation process of a partially unwound helical structure in ferroelectric liquid crystals.

The fluctuations of unwound helical structure have been observed in deformed helix ferroelectric liquid crystal (DHFLC) and conventional FLC sample cells. The helix is partially unwound by strong anchoring on the substrates. In such sample cells, the helical decarlization lines are not observed in the texture under crossed polarized microscope.

Para-meatal urethral cyst with bladder calculi: A case report and review of the literature.

Para-meatal urethral cyst or median raphe cyst of the glans penis is a benign cystic lesion uncommonly encountered in prepubertal age group. Approximately, about 50 cases have been reported till date in the world literature. Herein we report a case of para-meatal urethral cyst concurrent with urinary bladder calculi.

Extensive nephroureteric calcification presenting with renal failure: A rare case report.

The diagnosis of renal Tuberculosis (TB) can be hypothesized in the setting of non-specific bacterial cystitis associated with a therapeutic failure or a urinalysis with a persistent leukocyturia and absence of bacteriuria. Renal TB is an important cause of kidney disease, mainly in tropical areas of the globe, which can lead to end-stage renal disease if not diagnosed early and treated correctly. We report a case of a 58 year man with a past history of pulmonary TB treated for six months with extensive nephroureteric calcification presenting with renal failure.

Female Urethral Anomalies in Pediatric Age Group: Uncovered.

Female urethral anomalies such as epispadias and hypospadias have been rarely reported in the literature. Clinical diagnosis of female urethral anomalies is significant for management. Diagnosis may be missed leading to mismanagement of the clinical condition.

Probing the dynamics of geometrically confined ferroelectric mesogens at the air interface.

This article focuses on the alignment and dynamics of mesogens at the ferroelectric liquid crystal (FLC)/air interface in a confined geometry. The interface has been systematically prepared and characterised with provision for applying an electric field separately to the bulk and air interface of the FLC. Polarizing optical microscopy (POM) investigations done at the FLC/air interface have exposed the concave geometry, cell thickness dependent boundary width and phase dependent optical textures of the FLC meniscus at the interface.

Conservative management of accidental gall bladder puncture during percutaneous nephrolithotomy.

Percutaneous nephrolithotomy (PCNL) has been an excellent option for the management of kidney stones. There have been many complications in regards to solid organ injury during PCNL. Here we discuss an interesting case of 45-year-old woman, who underwent PCNL for right renal staghorn calculus, and had an accidental puncture of the gall bladder.

Advances in gold nanoparticle-liquid crystal composites.

We present the advancement in the research of the dispersion of gold nanoparticles (GNPs) in thermotropic calamitic liquid crystals. The formation/behavior of surface plasmon resonance (SPR) in GNPs is briefly described. The uniform dispersion of GNPs into liquid crystals along with two important aspects, i.

Kimura's Disease: A Case Report.

Kimura's disease is a rare, benign, slow-growing chronic inflammatory swelling with a predilection for the head and neck region and almost always with peripheral blood eosinophilia and elevated serum IgE levels. Here, we report a 14-year-old male patient with left-sided cheek swelling. It was painless swelling situated anterior to left ear, of 1 year duration, without any other symptoms.

Microstructural and electrochemical impedance characterization of bio-functionalized ultrafine ZnS nanocrystals-reduced graphene oxide hybrid for immunosensor applications.

We report a mercaptopropionic acid capped ZnS nanocrystals decorated reduced graphene oxide (RGO) hybrid film on a silane modified indium-tin-oxide glass plate, as a bioelectrode for the quantitative detection of human cardiac myoglobin (Ag-cMb). The ZnS nanocrystals were anchored over electrochemically reduced GO sheets through a cross linker, 1-pyrenemethylamine hydrochloride, by carbodiimide reaction and have been characterized by scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. The transmission electron microscopic characterization of the ZnS-RGO hybrid shows the uniform distribution of ultra-fine nanoparticles of ZnS in nano-sheets of GO throughout the material.

Enzyme-modified indium tin oxide microelectrode array-based electrochemical uric acid biosensor.

We fabricated a miniaturized electrochemical uric acid biosensor with a 3-aminopropyltriethoxysilane (APTES)-modified indium tin oxide (ITO) microelectrode array (μEA). The ITO-μEA on a glass plate was immobilized with the enzyme uricase, through a cross-linker, bis[sulfosuccinimidyl]suberate (BS). The enzyme-immobilized electrode (uricase/BS/APTES/ITO-μEA/glass) was characterized by atomic force microscopy and electrochemical techniques.

Electrochemical impedance spectroscopy characterization of mercaptopropionic acid capped ZnS nanocrystal based bioelectrode for the detection of the cardiac biomarker--myoglobin.

3-Mercaptopropionic acid (MPA) capped ZnS nanocrystals (ZnS(MPA)) are covalently attached to a self assembled monolayer (SAM) of 3-aminopropyltriethoxysilane (APTES) on an indium-tin-oxide (ITO) coated glass plate. The protein antibody, anti-myoglobin (Ab-Mb), is covalently linked to free carboxyl groups present on ZnS(MPA) nanocrystals via carbodiimide coupling reaction to form a bioelectrode (Ab-Mb(BSA)/ZnS(MPA)/APTES/ITO-glass). This bioelectrode has been characterized using atomic force microscopy (AFM), contact angle measurements, cyclic voltammetry and electrochemical impedance spectroscopy (EIS).

Optical memory effect in a deformed helix ferroelectric liquid crystal.

Optical memory in a deformed-helix ferroelectric liquid crystal is proposed by deforming the helix under the application of a square-voltage pulse of known magnitude and frequency. This effect is based on the electromechanical effect of helix deformation due to the electric field. When the interaction between the electric field and the dipole is sufficiently strong, all of the dipoles align along the electric field.