Investigation of 12 – 15 Kev Electron Transmission Through Tapered Glass Capillaries

Glass and Ceramics - The results of experimental studies of the transmission of 12 and 15 keV electron beams through tapered glass macro-capillaries are presented. Measurements showed that there is...     

Limiting sensitivity of photodetectors based on A3B5 photodiodes for middle infrared range

The noise of photodetectors based on mid-IR A³B⁵ photodiodes (PhDs) implemented in a transimpedance amplifier scheme is analyzed. Recommendations concerning the choice of amplifier elements depending on the dynamic resistance of PhDs are given. It is shown that, using modern low-noise amplifiers, it is possible to reach a potential limiting threshold sensitivity of photodetectors only using PhDs with dynamic resistances above 50 Ω.     

Color coding of the two-dimensional coordinates of events in position-sensitive radiation detectors

A new approach to determining the coordinates of events is proposed, which allows the point coordinates on a plane to be determined on line using a virtually single-channel readout system. According to the proposed method of color coding, each element of the area of a detecting target is assigned its color defined as a ratio of the component radiation wavelengths. Defined in this way, the color of the ith point on the mapping plane is in one to one correspondence with the (x _i , y _i ) coordinates of this point on the target.     

Hemi- and Homozygous Loss-of-Function Mutations in DSG2 (Desmoglein-2) Cause Recessive Arrhythmogenic Cardiomyopathy with an Early Onset

About 50% of patients with arrhythmogenic cardiomyopathy (ACM) carry a pathogenic or likely pathogenic mutation in the desmosomal genes. However, there is a significant number of patients without positive familial anamnesis. Therefore, the molecular reasons for ACM in these patients are frequently unknown and a genetic contribution might be underestimated. Here, we used a next-generation sequencing (NGS) approach and in addition single nucleotide polymor-phism (SNP) arrays for the genetic analysis of two independent index patients without familial medical history. Of note, this genetic strategy revealed a homozygous splice site mutation (DSG2–c.378+1G>T) in the first patient and a nonsense mutation (DSG2–p.L772X) in combination with a large deletion in DSG2 in the second one. In conclusion, a recessive inheritance pattern is likely for both cases, which might contribute to the hidden medical history in both families. This is the first report about these novel loss-of-function mutations in DSG2 that have not been previously identi-fied. Therefore, we suggest performing deep genetic analyses using NGS in combination with SNP arrays also for ACM index patients without obvious familial medical history. In the future, this finding might has relevance for the genetic counseling of similar cases.     

Specific Features of the Pyroelectric Effect in Epitaxial Aluminum Nitride Layers Obtained on Si Substrates

Technical Physics Letters - Pyroelectric effect has been studied in quasi-bulk AlN layers with thickness of 10–170 μm produced by hydride–chloride vapor-phase epitaxy on standard...     

Optical-fiber-tip temperature control system for fiber-coupled laser modules in medical equipment

An optical-fiber-tip temperature control device embedded into the power-supply unit of high-power laser diodes and modules (with fiber-optic output) used in medical laser equipment is proposed. As the sensing element, a III–V mid-infrared photodiode developed at the Ioffe Physical-Technical Institute is chosen from the photodiode class whose parameters are optimal for developing multipurpose thermal-radiation detectors (pyrometric sensors). The developed device allows temperature control at the working tip of the optical fiber of the laser “scalpel” in the range of 600–1100°C with an error no worse than 1% for a response time of 1 ms. The device has digital and analog temperature-signal outputs, which can be used to control the laser pump current, thus extending the functionality of medical laser equipment, increasing its efficiency, safety, and service life.