PCMW2D and 2D Raman correlation spectroscopy evidence for presence of spin-phonon coupling in hexagonal LuMnO3

Two-dimensional correlation spectroscopy (2D-COS) and perturbation-correlation moving window two-dimensional correlation spectroscopy (PCMW2D) analysis are performed on the temperature-dependent Raman spectra of hexagonal LuMnO₃ single crystal. Under the resonance with the on-site Mn d-d transitions, the correlation between the phonons which are relate to the vibration of Mn ions' bonds and spin-excitation peaks suggest a strong spin-phonon coupling in LuMnO₃. The PCMW2D results clearly show that the significant change in phonons and spin-excitation peaks occurs around the Néel temperature and the spin reorientation transition. The multiple components in the broad spin-excitation peaks also suggest variations in spin symmetries in the ground state. Furthermore, we propose that the 2D-COS and PCMW2D Raman correlation spectroscopies provide a simple and powerful method for investigating the couplings and the transitions, which would be very important for understanding systematically the magnetoelectric properties of multiferroic materials.

Entropy-Based Clustering Algorithm for Fingerprint Singular Point Detection

Fingerprints have long been used in automated fingerprint identification or verification systems. Singular points (SPs), namely the core and delta point, are the basic features widely used for fingerprint registration, orientation field estimation, and fingerprint classification. In this study, we propose an adaptive method to detect SPs in a fingerprint image. The algorithm consists of three stages. First, an innovative enhancement method based on singular value decomposition is applied to remove the background of the fingerprint image. Second, a blurring detection and boundary segmentation algorithm based on the innovative image enhancement is proposed to detect the region of impression. Finally, an adaptive method based on wavelet extrema and the Henry system for core point detection is proposed. Experiments conducted using the FVC2002 DB1 and DB2 databases prove that our method can detect SPs reliably.

Paramedic use of endotracheal tube introducers for the difficult airway

OBJECTIVE

To evaluate the ability of paramedics to learn and apply the skill of introducer-aided oral intubation in the setting of the simulated "difficult airway." The authors hypothesized that, following a brief introduction to the device, intubation success rates would not differ for traditional and introducer-aided intubations of an immobilized airway mannequin.

METHODS

During a paramedic recertification class, experienced paramedics were given a brief didactic introduction to the "bougie-like" Flex Guide endotracheal tube introducer (ETTI). The participants were then asked to intubate adult mannequins immobilized in the head-neutral position, with and without the ETTI. "Successful placement" was defined as completion of the procedure within 30 seconds and endotracheal tube position confirmed by the investigator with direct visualization.

RESULTS

For both traditional and ETTI intubations, 34 (97%) of the 35 paramedics successfully intubated within 30 seconds. The two unsuccessful intubation attempts were recognized by the paramedic as esophageal intubations, and correct tube placement was obtained within an additional 30 seconds.

CONCLUSION

In this study, use of the ETTI was mastered by the participants after only a brief didactic introduction to the device, with their ability to intubate an immobilized mannequin using the ETTI being equal to their ability to perform traditional intubation. These results suggest that use of the ETTI is easily learned, and may support the device's role in the prehospital management of the difficult airway.

Clinical aspects of Japanese B encephalitis in North Vietnam

The author reports the retrospective study of 116 children suffering from Japanese B encephalitis in recent epidemics. This disease often appeared in summer and affected 2 to 7-year-old children. In the acute stage the clinical picture included meningeal signs, motor disorders, consciousness dysfunction and neurovegetative disturbances. 90.4% of cases presented abnormal features in CSF. Serological tests with Nakayama and H.N-60 strains were positive. B.M-79 Arbo virus was isolated from 1 case. Neuropathological examination revealed typical lesions in 16 cases. Sero-, viro- and anatomical correlations with clinical course confirmed the role of J.B.E. in outbreaks of 'acute encephalitic syndrome' in North Vietnam.