J_{eff} Description of the Honeycomb Mott Insulator α-RuCl_{3}.

Novel ground states might be realized in honeycomb lattices with strong spin-orbit coupling. Here we study the electronic structure of α-RuCl_{3}, in which the Ru ions are in a d^{5} configuration and form a honeycomb lattice, by angle-resolved photoemission, x-ray photoemission, and electron energy loss spectroscopy supported by density functional theory and multiplet calculations. We find that α-RuCl_{3} is a Mott insulator with significant spin-orbit coupling, whose low energy electronic structure is naturally mapped onto J_{eff} states. This makes α-RuCl_{3} a promising candidate for the realization of Kitaev physics. Relevant electronic parameters such as the Hubbard energy U, the crystal field splitting 10 Dq, and the charge transfer energy Δ are evaluated.

Ultrasensitive and fast detection of denaturation of milk by coherent backscattering of light.

In this work, Coherence backscattering (CBS) of light has been used to detect the onset of denaturation of milk. The CBS cone shape and its enhancement factor are found to be highly sensitive to the physical state of the milk particles. The onset of denaturing of milk not visible to the naked eye, can be easily detected from changes in the CBS cone shape. The onset of denaturation is confirmed by spectral changes in Raman spectra from these milk samples. Further, the possibility to estimate the dilution of milk by water as an adulterant is demonstrated. The method reported has a broad scope in industry for making an inline ultrafast cost effective sensor for milk quality monitoring during production and before consumption.

Experimental study on modulation of Stokes parameters on propagation of a Gaussian Schell model beam in free space.

The effect on the Stokes parameters of a Gaussian Schell model beam on propagation in free space is studied experimentally and results are matched with the theory [X. H. Zhao, et al. Opt. Express 17, 17888 (2009)] that in general the degree of polarization of a Gaussian Schell model beam doesn't change on propagation if the three spectral correlation widths δ xx, δ yy, δ xy are equal and the beam width parameters σ x =σ y. It is experimentally shown that all the four Stokes parameters at the center of the beam decrease on propagation while the magnitudes of the normalized Stokes parameters and the spectral degree of polarization at the center of the beam remain constant for different propagation distances.

Effect of surface plasmons on spectral switching of polychromatic light with Au-double-slit.

It is shown that the generation of surface plasmons on a metal-dielectric interface, i.e., a Au-double-slit and air interface, appreciably affects the intensity of the diffracted light. With a specific example of Au-double-slit and electro-optic devices before the slits, the spectral switching in the diffracted field with the polychromatic light is shown for the first time, to our knowledge. It is found that at the observation point due to the surface plasmon effect the intensity of the diffracted light periodically increases and decreases with the separation of the double-slit.

Sciatic hernia causing sciatica: MRI and MR neurography showing entrapment of sciatic nerve.

Sciatic hernia is a rare condition with diverse clinical manifestations. We report a case of sciatic hernia causing sciatica, in which the diagnosis made on CT was subsequently confirmed on MRI including magnetic resonance neurography. The salient clinical and imaging features and a brief review are presented.

Effect of bleaching on color change and surface topography of composite restorations.

This study was conducted to determine the effect of 15% carbamide peroxide bleaching agent on color change and surface topography of different composite veneering materials (Filtek Z350 (3M ESPE), Esthet X (Dentsply India), and Admira (Voco, Germany). Methods. 30 samples were fabricated for evaluation of color change using CIELAB color system and Gonioreflectometer (GK 311/M, ZEISS). 45 disc-shaped specimens were made for evaluation of surface topography after bleaching (Nupro White Gold; Dentsply) using SEM. Statistical analysis. One way ANOVA and Multiple comparison tests were used to analyze the data. Statistical significance was declared if the P value was .05 or less. Results and conclusion. All the specimens showed significant discoloration (ΔE > 3.3) after their immersion in solutions representing food and beverages. The total color change after bleaching as compared to baseline color was significant in Filtek Z350 (P = .000) and Esthet X (P = .002), while it was insignificant for Admira (P = .18). Esthet X showed maximum surface roughness followed by Admira and Filtek Z350. Bleaching was effective in reducing the discoloration to a clinically acceptable value in all the three groups (ΔE < 3.3).

A rare case of combined soft-tissue and intraosseous arteriovenous malformation of the hand with diffuse periosteal elevation: imaging appearances.

Arteriovenous malformations are uncommon congenital lesions of the hand. Although present at birth, they usually manifest later in life. Ultrasonography, MRI and digital subtraction angiography play an important role in the diagnosis of these lesions. We report the imaging appearances of an unusual case of combined soft-tissue and intraosseous arteriovenous malformation (AVM) of the hand with marked periosteal elevation in a 12-year-old child. Although associated skeletal changes are common, diffuse periosteal elevation owing to direct communication of the AVM with the subperiosteal space has not, to the best of our knowledge, been reported previously.

Annular pancreas in an adult patient: diagnosis with endoscopic ultrasonography and magnetic resonance cholangiopancreatography.

Annular pancreas is an uncommon congenital anomaly that usually presents early in childhood. The role of endoscopic ultrasonography in the diagnosis of this condition has been only sparsely reported. We present annular pancreas in a 50-year-old man; the anomaly was initially suspected during endoscopy and endoscopic ultrasonography, and subsequently confirmed on magnetic resonance cholangiopancreatography.

Solitary fibrous tumour of the liver: a rare imaging diagnosis using MRI and diffusion-weighted imaging.

Solitary fibrous tumour of the liver is an extremely rare neoplasm, the reported imaging features of which are largely non-specific. We present a case in which dynamic contrast-enhanced CT, MRI and diffusion-weighted MRI findings suggested a diagnosis of solitary fibrous tumour of the liver that was subsequently confirmed by immunohistochemical evaluation.

Symptomatic perineural extension of fungal sinusitis in an immunocompetent person: imaging features.

Perineural spread is a rare mode of spread for fungal infection, even more so in immunocompetent individuals. We report a 21-year-old immunocompetent man in which symptomatic perineural extension of aspergillosis along the maxillary division of trigeminal nerve was accurately diagnosed on imaging.

Imaging appearance of parasitic infestations of the breast: a report of two cases and review of the literature.

Parasitic infestations of the breast are uncommon. They may occur as a part of generalized disease, or present as primary breast infestations, making diagnosis difficult. Clinically, they are difficult to differentiate from the more common breast pathologies. However, imaging plays an important role, and different modalities often help distinguish and diagnose these rare conditions.

Evaluation of thermal stability of indinavir sulphate using diffuse reflectance infrared spectroscopy.

Indinavir sulphate is a potent and specific protease inhibitor of human immunodeficiency virus (HIV). It is used for the treatment of acquired immune deficiency syndrome (AIDS). At elevated temperature the drug which otherwise remains crystalline undergoes a phase transition to an amorphous phase to form degradation products. In the present study, thermal stability of indinavir sulphate is evaluated using diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy. Infrared spectra of the drug before and after the exposure to thermal radiation at different temperatures were acquired in the diffuse reflectance mode using a Fourier transform infrared (FTIR) spectrophotometer. The differential scanning calorimetry (DSC) and the X-ray diffraction (XRD) studies were used as complimentary techniques to adequately implement and assist the interpretation of the infrared spectroscopy results. The DRIFT spectra reveal that the drug remains stable up to 100 degrees C, degrades slightly at 125 degrees C and undergoes complete degradation at about 150 degrees C to produce degradation products. The degradation products can easily be characterized using the infrared spectra.

Invasive sinus aspergillosis with perineural spread in an immunocompetent patient.

Invasive aspergillosis of paranasal sinuses is usually seen in immunocompromised patients and is associated with a very high mortality rate. The disease is distinctly uncommon in immunocompetent patients. A rare case of invasive aspergillosis of paranasal sinus and orbit with intracranial extradural extension via perineural spread along the maxillary division of the trigeminal nerve in an immunocompetent patient is presented.

Solid pseudopapillary tumor of the pancreas with portal vein compression presenting as portal hypertension.

Solid pseudopapillary tumour (SPT) of the pancreas is a rare neoplasm, which occurs predominantly in young females and is usually amenable to cure by surgical resection. Imaging plays an important role in its diagnosis. We present the sonographic, CT and MRI features of SPT in a young female whose chief complaint was recurrent haematemesis secondary to portal venous compression.

Diffuse cavernous haemangioma of colon: magnetic resonance imaging features. Report of two cases.

Large bowel haemangiomas are rare but can cause significant morbidity. The clinical features are non-specific, and misdiagnosis is very common. Non-invasive imaging is very useful in the diagnosis and management of this condition. Magnetic resonance imaging surpasses all other imaging modalities, as it is most specific and depicts the extent of the lesion accurately. Two cases of cavernous haemangioma of the rectum are presented highlighting the MRI features.

Congenital extrahepatic portosystemic venous shunt: imaging features.

Congenital extrahepatic portosystemic venous shunt (CEPS) is a rare anomaly. It causes metabolic derangements and is often associated with liver tumours and other anomalies. Imaging plays an important role in the diagnosis of CEPS. However, it may be misleading in determining the type of shunt. We present a six-year-old girl with CEPS to illustrate the importance of histology in determining the presence of portal veins in the portal triad, which were too small to be seen on imaging.

Craniodiaphyseal dysplasia: an unusual cause of recurrent dacryocystitis.

We describe a rare syndrome characterized by severe craniofacial hyperostosis, sclerosis, obliteration of paranasal sinuses and foramina of skull base, in a 10-year-old female child who presented with abnormal facial features and recurrent dacryocystitis due to narrowing of nasolacrimal duct.

Gastric teratoma.

Gastric teratoma is a very rare tumour that usually manifests as an abdominal mass, resulting in gastrointestinal bleeding and/or obstructive features. We report gastric teratoma occurring in a two-year-old boy who presented with an abdominal mass. Diagnosis was aided by the classical findings of teratoma on computed tomography, seen as the presence of fat, calcifications, and both solid and cystic areas.

Spontaneous pneumorrhachis in bronchial asthma.

We report on an 18-year-old male with bronchial asthma who presented with swelling over the neck and upper chest after a mild episode of bronchospasm. Physical examination was suggestive of subcutaneous emphysema, which was subsequently confirmed on a radiograph. Computed tomography in addition revealed pneumomediastinum and air within the epidural space of the spinal canal. Although spontaneous pneumomediastinum and subcutaneous emphysema have been described in a variety of situations, including patients with asthma, spontaneous pneumorrhachis in asthmatics is a very rare entity.