Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Miniaturization”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,621 records · Page 90Linked to original sources
PubMed2004

A case of shaker dog disease in a miniature dachshund.

A male miniature Dachshund, twenty-two months of age, was referred with paroxysmal generalized tremors as a main clinical sign. There were no abnormalities in the neurological examination except the lack of bilateral menace responses, and in the magnetic resonance imaging of its brain. Analysis of cerebro-spinal fluid revealed a slight rise in protein concentration and an increase in the number of cells. This case with brown hair was diagnosed as the shaker dog disease, which has also been well known as "little white shakers" syndrome due to being found in small dogs with white hair, because the clinical signs were exactly analogous to the shaker dog disease, and the generalized tremors disappeared on the first day after the administration of prednisolone and diazepam.

Animals↗
PubMed2006

Spinal nephroblastoma in a miniature Dachshund.

A 2-year-old castrated miniature Dachshund dog was presented to the Rakuno Gakuen Veterinary Teaching Hospital for diagnosis of progressive hindlimb paresis and ataxia. There was no thoracolumbar intervertebral disk hernia and magnetic resonance imaging revealed an intramedullary spinal cord lesion at the ninth and tenth thoracic vertebrae. Following surgical excision of the neoplasm, there was minor amelioration of neurological signs, but forelimb function was not recovered. The extracted tumor was histopathlogically diagnosed as spinal nephroblastoma.

Animals↗
PubMed2006

Long-term chemotherapy with lomustine of intracranial meningioma occurring in a miniature schnauzer.

A 14-year-old male miniature schnauzer was referred to us because it was circling to the right. A mass in the diencephalon was noted on brain magnetic resonance images. The dura was thickened with marked linear enhancement after contrast administration. Based on diagnostic image analysis, this lesion strongly suggested meningioma. The patient's symptoms were well controlled by a combination therapy of prednisolone and lomustine (CCNU), and survived for thirteen months after diagnosis. This case was diagnosed as a meningioma based on histopathological findings. This report describes the clinical findings, imaging characteristics, and pathologic features of a diencephalic and mesencephalic meningioma and long-term survival after lomustine and prednisolone therapy.

Animals↗
PubMed2006

Ossifying fibroma in a miniature rex rabbit (Oryctolagus cuniculus).

In humans and animals, ossifying fibroma is a benign neoplasm that most frequently affects the mandible, often resulting in cosmetic deformities and malocclusion. It is considered rare in animals and most frequently affects young horses. A surgical biopsy of a solitary mass located beneath the gingiva in the right maxillary region, which had overgrown teeth and expanded the adjacent hard palate from a 6-year-old miniature Rex rabbit was submitted for light microscopic examination. The submitted incisional biopsy specimen was pale pink, firm, and nodular. Histopathologically, the neoplasm was composed of fibroblastic cells separated by abundant collagen. The neoplastic cells were interwoven with osteoblasts surrounding islands of mineralized, bony matrix containing few, widely spaced, often empty, lacunae. Minimal inflammation was present. Based on the histopathologic features, the tumor was diagnosed as an ossifying fibroma. To our knowledge, this is the first report of an ossifying fibroma in a rabbit.

Animals↗
PubMed2006

Immunophenotypic characterization of peripheral blast cells in a leukemic miniature pig.

The health status of a 4-year-old female, dd-haplotype miniature pig deteriorated rapidly, so the animal finally had to be euthanized because of poor clinical condition. Necropsy revealed a massive leukocytic infiltration in the parenchymatous organs of the abdominal cavity. On hematologic cell counting, severe leukocytosis (69.3 x 10(9) cells/liter) and high-grade basophilia (6.9 x 10(9) cells/liter) were evident. Cytologic examination, as well as analysis of expression of leukocyte differentiation antigens by means of flow cytometry, classified blasts, which accounted for about 22% of leukocytes, as biphenotypic cells co-expressing the myeloid marker SWC3 (CD172a) and the lymphoid markers CD5 and CD25. Hematologic features resembled those seen in humans with chronic myeloid leukemia at blast phase.

Animals↗
PubMed2002

Simultaneous determination of curvature, plane of curvature, and temperature by use of a miniaturized sensing head based on fiber Bragg gratings.

We present what we believe to be a novel miniaturized sensor configuration based on fiber Bragg gratings for simultaneous measurement of curvature and temperature in smart structures and composite materials. Because of the particular geometry of the sensing head, it is possible not only to measure the radius of curvature but also to determine the plane of curvature. We arrange three Bragg gratings in the vertices of the smallest equilateral triangle that can be defined by the cross sections of the fibers. The set is then inserted into a glue-filled capillary stainless-steel tube to provide both suitable protection for the Bragg sensors and rotational symmetry to the sensing head. This tube also ensures isolation from axial strain, allowing for the additional determination of temperature. The proposed sensing head is particularly well suited for applications in smart structures because it can be embedded along any layer of a composite material (including the neutral line) without special concern for the relative orientation of the Bragg gratings and the composite layers. We can also use this sensing configuration to implement more-sophisticated sensors dedicated, for example, to the measurement of multiaxial acceleration or flow and temperature.

Journal Article↗
PubMed2002

Rapidly tuning miniature transversely excited atmospheric-pressure CO2 laser.

An experimental study of a rapidly tuning miniature transversely excited atmospheric-pressure CO2 laser is reported. To rapidly shift laser wavelengths over selected transitions in the 9-11 microm wavelength region, we have utilized a high-frequency stepping motor and a diffraction grating. The laser is highly automated with a monolithic microprocessor controlled laser line selection. For the achievement of stable laser output, a system of laser excitation with a voltage of 10 kV, providing effective surface corona preionization and allowing one to work at various gas pressures, is utilized. Laser operation at 59 emission lines of the CO2 molecule rotational transition is obtained and at 51 lines, the pulse energy of laser radiation exceeds 30 mJ. The system can be tuned between two different rotational lines spanning the wavelength range from 9.2 to 10.8 microm within 10 ms.

Journal Article↗
PubMed2005

Miniature fiber-optic pressure sensor with a polymer diaphragm.

The fabrication and experimental investigation of a miniature optical fiber pressure sensor for biomedical and industrial applications are described. The sensor measures only 125 microm in diameter. The essential element is a thin polymer diaphragm that is positioned inside the hollow end of an optical fiber. The cavity at the fiber end is made by a simple and effective micromachining process based on wet etching in diluted HF acid. Thus a Fabry-Perot interferometer is formed between the inner fiber-cavity interface and the diaphragm. The fabrication technique is described in detail. Different sensor prototypes were fabricated upon 125 microm-diameter optical fiber that demonstrated pressure ranges from 0 to 40 and from 0 to 1200 kPa. A resolution of less than 10 Pa was demonstrated in practice. The fabrication technique presented facilitates production of simple and low-cost disposable pressure sensors by use of materials with that ensure the required biocompatibility.

Journal Article↗
PubMed2004

Energy-scavenging amplifiers for miniature solid-state lasers.

Longitudinally pumped miniature lasers are inefficient, partly because of their inefficient absorption of the pump light. Scavenging the unabsorbed pump light to pump an in-line amplifier can greatly enhance the efficiency of the system, with minimal added cost, size, or complexity.

Journal Article↗
PubMed2005

Miniature fiber-optic multicavity Fabry-Perot interferometric biosensor.

A fiber-optic sensor is designed based on multicavity Fabry-Perot interferometry for the study of optical thickness in self-assembled thin-film layers. This miniature sensor is applicable not only to the measurement of self-assembled polyelectrolyte layers but also to the immobilization of proteins such as immunoglobulin G (IgG). The binding of IgG and the corresponding antigen is observed, and the nonspecific binding characteristics are investigated. The optical thickness changes are used to evaluate the immobilization of the IgG and the immunological activities of the immobilized layers.

Biosensing Techniques↗
PubMed2005

Nearly quantum-noise-limited timing jitter from miniature Er:Yb:glass lasers.

We report on nearly quantum-limited timing-jitter performance of two passively mode-locked Er:Yb:glass lasers with a repetition rate of 10 GHz. The relative timing jitter of both lasers was measured to be 190 fs (100 Hz-1.56 MHz) root mean square. The remaining cavity-length fluctuations are below 7.5 pm in the 6 Hz-8 kHz frequency range, indicating the stability of a rugged miniature cavity setup. By actively controlling the cavity length we reduced the timing jitter to 26 fs (6 Hz-1.56 MHz). We also discuss the influence of cavity length on the practically achievable timing jitter.

Journal Article↗
PubMed2005

Miniature all-silica fiber optic pressure and acoustic sensors.

We present a miniature diaphragm-based Fabry-Perot (F-P) interferometric fiber optic sensor fabricated by novel techniques for pressure or acoustic wave measurement that is only approximately 0.32 mm in diameter. By choosing different diaphragm thicknesses and effective diameters, we obtain a sensor measurement range from 5 to 10,000 psi (1 psi = 51.72 Torr) and a frequency response up to 2 MHz. In addition, the sensor's F-P cavity can be set from micrometers to millimeters with a precision of several nanometers. With the all-silica structure, the sensor is reliable, biocompatible, and immune to electromagnetic interference and has high-temperature sensing capability.

Journal Article↗
PubMed2006

All-fused-silica miniature optical fiber tip pressure sensor.

An all-fused-silica pressure sensor fabricated directly onto a fiber tip of 125 microm diameter is described. Simple fabrication steps include only cleaving and fusion splicing. Because no chemical processes are involved, the fabrication is easy, safe, and cost effective. Issues in sensor design and loss analysis are discussed. The sensor has been tested for static pressure response, showing a sensitivity of 2.2 nm/psi, a resolution of 0.01 psi (68.9 Pa), a hysteresis of 0.025%, and capability of operation at temperatures up to 600 deegrees C. This miniature sensor may be suitable for medical diagnostics, environmental monitoring, and other industrial applications.

Journal Article↗
PubMed2006

Wedged etalon tuning for miniature and monolithic lasers.

We present an architecture permitting broad tuning of monolithic microchip lasers by using a wedged etalon. Full tuning from 282 to 314 nm is demonstrated by using a miniature Ce:LiCAF laser design, where tuning is achieved by translating the entire Ce laser cavity relative to the pump beam. The application of this technique to a range of microchip lasers will lead to extremely robust tunable monolithic lasers.

Journal Article↗
PubMed1998

Preoperative diagnosis with video-assisted thoracoscopy with miniaturized endoscopes in general thoracic surgery: a preliminary study.

Video-assisted thoracoscopy using a miniaturized endoscope (mini-VAT) was applied for preoperative diagnosis in general thoracic surgery. Thirty-one patients, including 27 with indeterminate pulmonary nodule and 4 with suspected pleural involvement of lung cancer or metastatic pleural tumor, underwent mini-VAT. As a pilot study, 14 of the former 27 patients underwent mini-VAT while receiving general anesthesia. As a prospective study, all the remaining 17 patients underwent mini-VAT while receiving local anesthesia. Solid scopes of three different sizes, 0.9, 1.9, or 4.0 mm diameter, were used. An artificial pneumothorax for scope introduction was produced by needle thoracentesis under atmospheric pressure. Automatic cutting needle biopsy was used for tissue sampling. In the pilot study group, mini-VAT with a 4.0-mm scope provided excellent visibility and diagnostic sensitivity of 100%. This study group showed the diagnostic sensitivity of needle biopsy for pulmonary nodule to be 100%. Hemorrhages and air leaks at biopsy sites were sealed with blood coagulation in a short time. In the prospective study group, mini-VAT with a 4.0-mm scope with the patients receiving local anesthesia provided a diagnostic sensitivity of 91% for pulmonary nodule and a diagnostic accuracy of 100% for suspected pleural involvement. Causes of failure of mini-VAT with the use of local anesthesia were cough reflex during needle biopsy and incomplete lung collapse for deeply located target in two cases. The adverse effects of the mini-VAT were paradoxical respiration in two cases in which local anesthesia was used. The patients who received only local anesthesia required no chest tube drainage. Mini-VAT is a simple, minimally invasive procedure suitable as a preoperative examination technique for histologic diagnosis, evaluation of disease progression, and selection of strategy in thoracic surgery.

Adult↗
PubMed2006

Polymerase chain reaction in miniaturized systems: big progress in little devices.

A critical need exists for advanced technologies that enable genomic-based DNA analysis to be performed with significantly higher throughput and at a significantly lower cost than is attainable with current hardware. Miniaturized polymerase chain reaction systems offer an attractive platform to address these needs, combining the ability to perform rapid thermocycling with a portable device format that can be inexpensively mass produced. We review recent efforts aimed at developing these next-generation systems and discuss some of the practical considerations involved in adapting this technology for routine laboratory use.

Electrophoresis, Microchip↗
PubMed2002

Defining the period of recovery of the glucose concentration after its local perturbation by the implantation of a miniature sensor.

At the wound caused by implanting a subcutaneous glucose sensor, the concentration of glucose differs transiently from that in the subcutaneous fluid near non-wounded skin. The period of recovery differs for different wounds and is difficult to predict. A diabetic patient implanting a subcutaneous sensor needs to know whether the transient difference subsided sufficiently for the sensor readings and the sensor's in vivo calibration to be valid. The miniature amperometric glucose sensor has a compound membrane including a layer of glucose oxidase the reaction centers of which are electrically connected to the electrode through a redox polymer; layers excluding interferents and poisons of the electrocatalytic oxidation of glucose; and a layer reducing fouling by components of the biological fluids. We show that the sensor maintains its in vitro sensitivity after its implantation for four hours in the jugular vein and in the peritoneal fluid of the rat. For a diabetic patient who implants the sensor the four-hour period is long enough for the insertion-trauma-caused local perturbation of the glucose concentration to subside and to safely rely on the readings of the implanted sensor.

Animals↗
PubMed2006

Phosphatidylinositol 3 kinase activation and AMPA receptor subunit trafficking underlie the potentiation of miniature EPSC amplitudes triggered by the activation of L-type calcium channels.

We have characterized a mechanism by which the amplitudes of miniature EPSCs (mEPSCs) in CA1 pyramidal neurons in rat hippocampal organotypic slice cultures are potentiated by approximately twofold after a series of depolarizing voltage pulses from -80 to +20 mV. The increase in mEPSC amplitudes is triggered by the activation of L-type calcium channels and is independent of NMDA receptor (NMDAR) activation but also requires calcium release from intracellular stores. The potentiation induced by depolarizing pulses does not alter the kinetic parameters of mEPSCs. The induction phase of this potentiation involves phosphatidylinositol 3 kinase (PI3 kinase) activation because it is blocked completely in the presence of the PI3 kinase inhibitors wortmannin and 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002). Furthermore, we show that the maintenance phase of depolarizing pulse potentiation requires continued PI3 kinase activity because the application of either wortmannin or LY294002 results in a reversal to control levels of the amplitudes of mEPSCs. Finally, we demonstrate that the increase in mEPSC amplitudes is mediated by the increased expression of functional AMPA receptors (AMPARs) because the potentiation is blocked by N-ethylmaleimide, botulinum toxin A, and a variety of short-sequence peptides that disrupt the interaction of AMPAR subunits with proteins involved with the trafficking of these to the cell membrane. Our data are consistent with the notion that PI3 kinase and membrane fusion/trafficking events play a pivotal role in coordinating changes in synaptic strength, mediated by AMPA receptors, which are triggered by alterations in postsynaptic calcium concentrations whether these changes are initiated via NMDAR-dependent or NMDAR-independent routes.

Animals↗