PubMed Health⌕ Search

PubMed · 16279476

Raman probe using a single hollow waveguide.

Abstract

A simple Raman probe was realized using a single flexible hollow waveguide (HW). A HW coated with a silver film, which had reasonable transmission and little optical background noise, was used as a bidirectional transmission fiber for both the excitation and collection of Raman scattered light. The HW itself generated no Raman scattering or fluorescence noise during transmission. A complex filtering system at the end of the waveguide was thus unnecessary. In addition, the measured Raman spectra showed better signal-to-noise ratios than a conventional Raman fiber probe. The HW's suitability as a Raman fiber probe was also demonstrated.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yuichi Komachi, Hidetoshi Sato, Yuji Matsuura, Mitsuno Miyagi, Hideo Tashiro. 2005-11-01. Raman probe using a single hollow waveguide.. https://doi.org/10.1364/ol.30.002942

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

In vivo myograph measurement of muscle contraction at optimal length.

BACKGROUND: Current devices for measuring muscle contraction in vivo have limited accuracy in establishing and re-establishing the optimum muscle length. They are variable in the reproducibility to determine the muscle contraction at this length, and often do not maintain precise conditions during the examination. Consequently, for clinical testing only semi-quantitative methods have been used. METHODS: We present a newly developed myograph, an accurate measuring device for muscle contraction, consisting of three elements. Firstly, an element for adjusting the axle of the device and the physiological axis of muscle contraction; secondly, an element to accurately position and reposition the extremity of the muscle; and thirdly, an element for the progressive pre-stretching and isometric locking of the target muscle. Thus it is possible to examine individual in vivo muscles in every pre-stretched, specified position, to maintain constant muscle-length conditions, and to accurately re-establish the conditions of the measurement process at later sessions. RESULTS: In a sequence of experiments the force of contraction of the muscle at differing stretching lengths were recorded and the forces determined. The optimum muscle length for maximal force of contraction was established. In a following sequence of experiments with smaller graduations around this optimal stretching length an increasingly accurate optimum muscle length for maximal force of contraction was determined. This optimum length was also accurately re-established at later sessions. CONCLUSION: We have introduced a new technical solution for valid, reproducible in vivo force measurements on every possible point of the stretching curve. Thus it should be possible to study the muscle contraction in vivo to the same level of accuracy as is achieved in tests with in vitro organ preparations.

Equipment Design↗

Special anoscope for easy purse-string suture application in stapled hemorrhoidopexy.

BACKGROUND: Internal hemorrhoids and loose rectal mucosa may block exposure during the purse-string suturing in stapled hemorrhoidopexy, and this may lead to complications. MATERIALS AND METHODS: To retract the prolapsing rectal mucosa, we modified the purse-string anoscope of the PPH01 kit (Ethicon-Endosurgery, Cincinnati, OH, USA) and produced a special anoscope. The open part of the purse-string suture anoscope is covered by transparent acrylic (Orthoacryl, Dentaurum, Pforzheim, Germany). The covering had completely cylindrical outer and inner surfaces and was thin enough to let the anoscope easily rotate in the anal dilator and to let the 26 mm curved, round-bodied needle of the 2/0 polypropylene suture move in the anoscope. A window, 3 cm long and 3-4 mm wide, was opened at the angled part of the anoscope 2 cm to the tip. This special anoscope was used for the purse-string suture during the stapled hemorrhoidopexy procedure in five patients. RESULTS AND CONCLUSIONS: No postoperative complications, early or late, were encountered, and we propose that stapled hemorrhoidopexy procedure can be applied more easily by using this special anoscope.

Equipment Design↗

Microtubule transport, concentration and alignment in enclosed microfluidic channels.

The kinesin-microtubule system has emerged as a versatile model system for biologically-derived microscale transport. While kinesin motors in cells transport cargo along static microtubule tracks, for in vitro transport applications it is preferable to invert the system and transport cargo-functionalized microtubules along immobilized kinesin motors. However, for efficient cargo transport and to enable this novel transport system to be interfaced with traditional microfluidics, it is important to fabricate enclosed microchannels that are compatible with kinesin motors and microtubules, that enable fluorescence imaging of microtubule movement, and that provide fluidic connections for sample introduction. Here we construct a three-tier hierarchical system of microfluidic channels that links microscale transport channels to macroscopic fluid connections. Shallow microchannels (5 microm wide and 1 microm deep) are etched in a glass substrate and bonded to a cover glass using PMMA as an adhesive, while intermediate channels (approximately 100 microm wide) serve as reservoirs and connect to 250 microm deep microchannels that hold fine gauge tubing for fluid injection. To demonstrate the utility of this device, we first show the performance of a directional rectifier that redirects 96% of moving microtubules and, because any microtubules that detach rapidly rebind to the motor-coated surface, suffers no microtubule loss over time. Second, we develop an approach, using a headless kinesin construct, to eliminate gradients in motor adsorption and microtubule binding in the enclosed channels, which enables precise control of kinesin density in the microchannels. Finally, we show that a 60 microm diameter circular ring functionalized with motors concentrates and aligns bundles of approximately 3000 uniformly oriented microtubules, while suffering negligible ATP depletion. These aligned isopolar microtubules are an important tool for microscale transport applications and can be employed as a model in vitro system for studying kinesin-driven microtubule organization in cells.

Equipment Design↗