Low-level laser therapy (LLLT) using superpulsed near-infrared light can penetrate deeper in the injured tissue and could allow non-pharmacological treatment for chronic wound healing. This study investigated the effects of superpulsed laser (Ga-As 904 nm, 200 ns pulse width; 100 Hz; 0.7 mW mean output power; 0.4 mW/cm(2) average irradiance; 0.2 J/cm(2) total fluence) on the healing of burn wounds in rats, and further explored the probable associated mechanisms of action. Irradiated group exhibited enhanced DNA, total protein, hydroxyproline and hexosamine contents compared to the control and silver sulfadiazine (reference care) treated groups. LLLT exhibited decreased TNF-α level and NF-kB, and up-regulated protein levels of VEGF, FGFR-1, HSP-60, HSP-90, HIF-1α and matrix metalloproteinases-2 and 9 compared to the controls. In conclusion, LLLT using superpulsed 904 nm laser reduced the inflammatory response and was able to enhance cellular proliferation, collagen deposition and wound contraction in the repair process of burn wounds. Photomicrographs showing no, absence inflammation and faster wound contraction in LLLT superpulsed (904 nm) laser treated burn wounds as compared to the non-irradiated control and silver sulfadiazine (SSD) ointment (reference care) treated wounds.

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When a person is emotionally charged, stress could be discerned in his voice. This paper presents a simplified and a non-invasive approach to detect psycho-physiological stress by monitoring the acoustic modifications during a stressful conversation. Voice database consists of audio clips from eight different popular FM broadcasts wherein the host of the show vexes the subjects who are otherwise unaware of the charade. The audio clips are obtained from real-life stressful conversations (no simulated emotions). Analysis is done using PRAAT software to evaluate mean fundamental frequency (F0) and formant frequencies (F1, F2, F3, F4) both in neutral and stressed state. Results suggest that F0 increases with stress; however, formant frequency decreases with stress. Comparison of Fourier and chirp spectra of short vowel segment shows that for relaxed speech, the two spectra are similar; however, for stressed speech, they differ in the high frequency range due to increased pitch modulation.

Background: Voice, apart from its semantic content also carries information about the speaker's psychological and physical state. Emotional stress or physical fatigue, are the pathological elements of this condition. The possible relationship between emotional stress and the measurable changes to the voice signal was the subject of this study. Method: Eleven subjects were interviewed with questions from two domains and their responses were recorded. In the first domain, two men, two women and three teenagers were asked to remember an incident from their past where they felt embarrassed or ashamed of their own act. In the second domain, three women and one man from the house keeping staff were interviewed for the stolen mobile phone. These subjects were different from the subjects who participated in domain 1. Stress in voice was detected as a measure of shift in the acoustic parameters with respect to the baseline. All recordings were analyzed using PRAAT software. Spectrograms were also plotted for qualitative comparison between normal speech and stressed speech.Result: Significant increase in mean pitch and substantial decrease in the first two formants (F1 and F2) were observed under stress. Other acoustic measures did undergo change under stress but failed to reveal any significance. Spectrograms were distinct for the two conditions. Conclusion: Obtained results indicate that, when a person is emotionally charged, stress could be discerned in his voice. Mean pitch and Formants F1 and F2 have been obtained as reliable vocal indicators of emotional stress. This study proposes a simple non-invasive approach which can act as an alibi for innocent people. General TermsVoice stress analysis, speech processing, human computer interface.

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