Search

Harlequin syndrome (HS) is a rare disorder of the sympathetic nervous system which presents with unilateral decreased sweating and flushing of the face, neck, and chest in response to heat, exercise, or emotional factors. The contralateral side displays a compensatory overreaction to provide normal heat regulation of the face as a whole. In the literature, most of the cases are primary in nature and no underlying cause could be identified. Harlequin sign is used to denote these symptoms in patients who also exhibit associated oculosympathetic paresis, such as Horner syndrome, Adie syndrome, and Ross syndrome.We report a rare case of a 13-year-old boy who presented with complaints of flushing and sweating of the left side of the face after exertion, while the right side remained dry and maintained its normal color. No structural abnormality was identified on detailed work up. Thus, diagnosis of classic idiopathic HS was made. Despite the rarity of this syndrome, dermatologists should be acquainted with this distinctive entity and should refer the patient for complete ophthalmological and neurological examination.

Griscelli Syndrome (GS) is a rare autosomal recessive disorder characterized by pigmentary dilution of the hair and skin (partial albinism). Three different types (1-3) caused by mutation in three different genes have been described. Patients with GS type 1 have primary central nervous system dysfunction; type 2 patients commonly develop hemophagocytic lymphohistiocytosis and type 3 patients present with partial albinism only. Two siblings discussed here had silvery hair, eyebrows and eyelashes since birth with no features suggestive of immunodeficiency or neurological impairment, making it an even rarer presentation of Griscelli Syndrome, type 3. Diagnosis was confirmed on light microscopy (LM) of hair shafts. Both GS1 and GS2 have been described earlier. However, extensive search of the literature failed to reveal a similar presentation from Indian origin. This is the first ever report of GS-3 in non-identical siblings from India.

In the current work, numerical simulation and experimentation are carried out to investigate the performance of powder mixed dielectric in the electrical discharge micromachining process. Three distinct powders, namely aluminum (electrically conductive), silicon (semi-conductive), and aluminum oxide/alumina (electrically non-conductive) dispersed in the kerosene dielectric, are considered. For a constant applied voltage, a silicon powder particle inserted in the gap immersed with liquid dielectric shows an enlargement in the inter-electrode gap (∼38% and 63% with circular and elliptical powder) compared to the pure dielectric. The enlarged inter-electrode gap increases the machining yield due to improved flushing efficiency. The intensification of the electric field near the particles' surface lowers the breakdown voltage and charging time of the capacitor for the constant inter-electrode gap, resulting in a decrease in discharge energy per pulse and increased spark frequency. The influence of powder material properties and their sizes on breakdown strength is analyzed. Further, the discharge parameters acquired from the electric field numerical simulation of powder mixed dielectric have been utilized to conduct the numerical simulation of single crater formation with pure dielectric and powder mixed dielectric. The simulated single carters' dimensions are validated with the experimentally machined single craters. Numerical simulation and experimentation of powder mixed dielectric depict the effectiveness of aluminum oxide powders in addition to silicon and aluminum powders when dispersed in kerosene host dielectric. [ABSTRACT FROM AUTHOR]