Optimization of hollow waveguides as absorption cells for spectroscopic gas sensing

Flexible and low-loss hollow waveguide has many advantages as an absorption cell for spectroscopic gas sensing. The characteristics of the sensing system are dependent on the parameters of the hollow waveguide cell. In this paper, a mathematical model was proposed to analyze the waveguide cell by considering waveguide loss, effective optical path length, and signal-to-noise ratio of the system. Simulation results show that the gas absorption intensity and system sensitivity are dependent not only on the waveguide length but also on the bore-diameter, signal-to-noise ratio, and the concentration of the target gases. The results provide optimizing methods for the sensing system and algorithms for error compensation. Preliminary experiments on concentration detection of methane gas were carried out and measured data showed good agreements with the simulation results.

Novel nonsense and frameshift NTRK1 gene mutations in Chinese patients with congenital insensitivity to pain with anhidrosis

Congenital insensitivity to pain with anhidrosis (CIPA; MIM 256800) is a rare autosomal recessive disorder characterized by absence of reaction to noxious stimuli, recurrent episodes of fever, anhidrosis, and mental retardation. It is caused by mutations in the gene coding for neurotrophic tyrosine kinase receptor type 1 (NTRK1; MIM# 191315). We screened two Chinese CIPA cases for mutations in the NTRK1 gene and examined their phenotype. Two novel mutations of the NTRK1 gene and two known mutations were identified. Including our two novel mutations, there are now 62 different NTRK1 gene mutations reported in patients with CIPA. We find that a combination of two null alleles usually leads to the severe phenotype, while the mild form of the CIPA disease is associated with at least one mild allele. Thirty-four among the 62 mutations (55%) are located within the tyrosine kinase domain of the NTRK1 protein. We concluded that the tyrosine kinase domain is a hot spot for mutations.

Pyoderma gangraenosum caused by Rhizopus arrhizus

A rare case of pyoderma gangraenosum caused by Rhizopus arrhizus is reported. The patient, a 50-year-old male farmer, was admitted to hospital complaining of gangrening and festering of the right upper arm with severe pain for nearly 2 months. A lesion was found on the inside of right upper arm. The central skin part of the lesion became black dry gangrenous, the periphery was deeply ulcerated with yellow-green pus. The necrotic crust, biceps, triceps and vessels inherited a histopathologically proven fungal infection. The fungus isolated was identified as Rhizopus arrhizus. The infection was successfully treated with itraconazole.

[Preliminary analysis of 18 cases of malignant lymphoma by immunohistological method with various monoclonal and polyclonal antibodies]

Eighteen cases of malignant lymphoma were labelled by ABC immunohistologic method with various monoclonal and polyclonal antibodies. It was found that all were OKT9 antiserum positive and cytokeratin negative. In B cell lymphomas, 9/18 cases were positive for B1; 7 positive for each of I2+ and Leu 10+; 6 for J5+, and 5 for B2+. In 6 cases of T cell lymphoma, 5 cases were positive for T3+ and Tac+ each; 4 for T11+ and 2 for T6+ while all were positive for T4 and negative or weakly positive for T8A. There was 1 case of histiocytic lymphoma and 2 of Hodgkin's lymphoma showing positive reaction to MO1, 2H9 and lysozyme antibody in their tumor cells and R-S cells.