Morvan Syndrome and Diffuse Large B-Cell Lymphoma in the Central Nervous System.

INTRODUCTION: The origin of contactin-associated protein-like 2 (Caspr2) antibodies in patients with Morvan syndrome is currently unknown. This case report investigated a possible association between the production of Caspr2 antibodies and aberrant proliferation of B lymphocytes. CASE REPORT: We admitted a critically ill 65-year-old female patient with a suspected infection of the central nervous system (CNS). In addition to acquired neuromyotonia and CNS involvement, Caspr2 antibodies detected in her serum led to the presumptive diagnosis of Morvan syndrome. However, steroid and immunoglobulin treatment did not result in a satisfactory therapeutic outcome. On the basis of findings from immunohistochemistry, flow cytometric analysis, and immunoglobulin/T-cell receptor gene rearrangement detection of cerebrospinal fluid cells, we also made a concurrent diagnosis of diffuse large B-cell lymphoma in the CNS of this patient. The patient then received 4 cycles of rituximab and methylprednisolone therapy with an interval of 2 weeks, which temporarily led to a near-complete remission of her symptoms. Upon follow-up, her symptoms relapsed at 3 months after the last treatment with rituximab and methylprednisolone. CONCLUSIONS: This is a first reported case of a patient who was concurrently diagnosed with Morvan syndrome and diffuse large B-cell lymphoma in the CNS. Additional studies are needed to determine whether aberrantly proliferating B lymphocytes are responsible for the production of Caspr2 antibodies.

High sensitivity fiber sensor for measurement of Cd2+ concentration in aqueous solution based on reflective Mach-Zehnder interference with temperature calibration.

We propose a novel fiber chemical sensing system based on reflective Mach-Zehnder interference with temperature calibration for the measurement of Cd2+ in aqueous solution. The sensing system has high measurement sensitivity of Cd2+ with an estimated minimum detection limit of 4×10-7 mol/L at a spectral resolution of 0.02 nm and with long-term stability. The fiber sensing head is prepared by coating a sensing membrane on a fused tapering single-mode fiber. The thiourea group of the sensing membrane has an effective combination effect on Cd2+. Disturbance from ambient temperature fluctuation on the measurement of Cd2+ concentration can be eliminated with the fiber Bragg grating.

Performance improvement of GaN-based LEDs with step stage InGaN/GaN strain relief layers in GaN-based blue LEDs.

The performance of nitride-based LEDs was improved by inserting dual stage and step stage InGaN/GaN strain relief layer (SRL) between the active layer and n-GaN template. The influences of step stage InGaN/GaN SRL on the structure, electrical and optical characteristics of GaN-based LEDs were investigated. The analysis of strain effect on recombination rate based k·p method indicated 12.5% reduction of strain in InGaN/GaN MQWs by inserting SRL with step stage InGaN/GaN structures. The surface morphology was improved and a smaller blue shift in the electroluminescence (EL) spectral with increasing injection current was observed for LEDs with step stage SRL compared with conventional LEDs. The output power of LEDs operating at 20 mA was about 15.3 mW, increased by more than 108% by using step stage InGaN/GaN SRL, which shows great potential of such InGaN/GaN SRL in modulating InGaN/GaN MQWs optical properties based on its strain relief function.

Valence subband coupling effect on polarization of spontaneous emissions from Al-rich AlGaN/AlN quantum wells.

The optical polarization properties of Al-rich AlGaN/AlN quantum wells (QWs) were investigated using the theoretical model based on the k·p method. Numerical results show that there is valence subband coupling which can influence the peak emission wavelength and emission intensity for TE and TM polarization components from Al-rich AlGaN/AlN QWs. Especially the valence subband coupling could be strong enough when CH1 is close to HH1 and LH1 subbands to modulate the critical Al content switching dominant emissions from TE to TM polarization. It is believed that the valence subband coupling may give important influence on polarization properties of spontaneous emissions and should be considered in designing high efficiency AlGaN-based ultraviolet (UV) LEDs.