Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Telescopes”

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 127 records · Page 7Linked to original sources
PubMedDate not supplied

Tooth-supported telescopic crown-retained dentures: an up to 9-year retrospective clinical follow-up study.

PURPOSE: This study evaluated outcome and quality of treatments with telescopic crown-retained dentures. MATERIALS AND METHODS: A total of 72 subjects (27 men and 45 women; mean age 67 years) wearing 75 telescopic crown-retained dentures (18 in the mandible and 57 in the maxilla) participated in the study. There were a total of 368 abutment teeth, 272 in the maxilla and 96 in the mandible. Each patient was clinically examined. Using the CDA evaluation system, four calibrated evaluators also examined, independently, the inner crowns for margin integrity and the superstructure for retention, occlusion, stability, wear, and esthetic appearance. Observer consistency was measured with Cohen's kappa. RESULTS: The observation period varied from 9 months to 9.3 years (mean 3.8 years). One telescopic crown-retained denture was lost, and 24 abutment teeth (7%) were extracted during the observation period. In 49 abutment teeth (13%), technical complications had occurred, and a total of four framework fractures (5%) were observed. Based on the CDA criteria, most of the characteristics were evaluated as satisfactory. The characteristics "condition of denture-supporting soft tissue" and "superstructure wear" showed the highest frequencies of not acceptable ratings, 44% and 45%, respectively. CONCLUSION: In this retrospective follow-up study, satisfactory outcome was found for tooth-supported telescopic crown-retained dentures over a mean observation period of 3.8 years.

Adult↗
PubMed2006

[Galileo and his telescope].

Galileo's publication of observations made with his newly reinvented telescope provoked a fierce debate. In April 1610 Martinus Horky, a young Bohemian astronomer, had an opportunity to make his own observations with Galileo's telescope in the presence of Antonio Magini and other astronomers. Horky and the other witnesses denied the adequacy of Galileo's telescope and therefore the bona fides of his discoveries. Kepler conjectured Horky as well as all his witnesses to be myopic. But Kepler's objection could not stop the publication of Horky's Peregrinatio contra nuncium sidereum (Modena, 1610), the first printed refutation of Galileo's Sidereus nuncius. In his treatise, Horky adresses four questions: 1) Do the four newly observed heavenly bodies actually exist? Horky denies their existence on various grounds: a) God, as every astronomer teaches, has created only seven moveable heavenly bodies and astronomical knowledge originates in God, too. b) Heavenly bodies are either stars or planets. Galileo's moveable heavenly bodies fit into neither category. c) If they do exist, why have they not already been observed by other scholars? Horky concludes that there are no such heavenly bodies. 2) What are these phenomena? They are purely artefactual, and produced by Galileo's telescope. 3) How are they like? Galileo's "stars" are so small as to be almost invisible. Galileo claims that he has measured their distances from each other. This however is impossible due to their diminutive size and other observational problems. Hence, Galileo's claim is a further proof that he is a fraud. 4) Why are they? For Galileo they are a chance to earn money but for astronomers like Horky they are a reason to offer thanks and honour to God. Horky's treatise was favourably received by the enemies of Galileo. But Kepler's critique was devastating. After calling on Kepler in Prague, Horky had to revoke the contents of his book.

English Abstract↗
PubMed1989

Predictors of functional success in telescopic spectacle use by low vision patients.

Telescopic spectacles can theoretically improve function of low vision patients by enlarging retinal images. However, unintended head movement may produce sufficient instability of enlarged retinal images to negate the visual benefit. We investigated this phenomenon as a cause of failure in 38 low vision patients who had previously attempted use of telescopic spectacles. Patients underwent evaluation of the vestibulo-ocular reflex, visual-vestibulo-ocular reflex, head stability in the pitch and yaw axes, and sensitivity of magnified visual acuity to head motion. Although it was impossible to distinguish successful from unsuccessful telescopic spectacle users by means of clinical or historical data, multiple logistic regression analysis was used to derive a useful predictive function based on measurements of sensitivity of magnified vision to head motion, and head instability in the pitch axis. Predictive performance was found to be superior to conventional clinical judgement. These findings support the hypothesis that retinal image stability is important to functional vision, and suggest that head-stabilizing strategies may improve function with telescopic spectacles in certain low vision patients.

Adult↗
PubMed1979

Field "expansion" by use of binocular full-field reversed 1.3X telescopic spectacles: a case report.

Full-field reversed 1.3X telescopes were used in the treatment of a 63-year-old male retinitis pigmentosa (R.P.) patient with a 5 degree central field. The patient was highly motivated to "expand" his visual field. He was trained intensively with 1.3X, 1.7X, and 2,2X reversed telescopes prior to prescribing. Evaluations by the Orientation and Mobility staff indicated significant improvements in his functioning with the devices. The reversed telescopes expanded his field to approximately 14 degrees. Patient has been reevaluated after using the aid at home and remains enthusiastic about his successful use of the aid. This case is notable in that binocular, low-power, full-field, reversed telescopes are being used successfully for mobility, eating, and other tasks.

Activities of Daily Living↗
PubMed1995

A profile of the demographics, training and driving history of telescopic drivers in the state of Michigan.

BACKGROUND: Five-hundred twenty-eight licensed, telescopic drivers in the state of Michigan, were sent a questionnaire consisting of 50 questions to evaluate the demographics, formal training procedures experienced by these drivers, and their driving habits. METHODS: One-hundred forty-nine responses were tabulated to determine the characteristics of the telescopic driver in the state of Michigan. RESULTS: The findings show an increased necessity for dynamic assessment, training and follow-up of the telescopic wearer and for referral to a specific driving program to establish safe driving skills. CONCLUSION: As the field of low vision expands in its delivery of care, and with improvement in technology, the desire for telescopic driver's licenses will increase. The need for dynamic training procedures delivered by the multidisciplinary rehabilitative team becomes even more vital to ensure safe driving skills and to protect the privilege to drive. Extensive training, followup and communication must be an integral part of this process.

Adolescent↗
PubMed1994

A new concept of overdentures with telescope crowns on osseointegrated implants.

Primary splinting of fixtures with bar attachments has proven to be clinically effective for overdentures on osseointegrated implants in the edentulous mandible. However, in vitro investigations indicate that a more favorable force transfer to the individual fixtures can be attained by secondary splinting of four implants with tapered telescope crowns, compared to primary splinting with rigid or jointed bar attachments. Moreover, in contrast to jointed attachments, the telescope crowns ensure a stable denture position. These results underscore the need to clinically test telescope crowns as anchors for overdentures on osseointegrated implants. Telescope crowns on four implants allow an optimal restorative concept of overdentures with the bridgelike design of the removable suprastructure.

Crowns↗
PubMed1997

Spectacle/loupe telescope designed for reading music.

BACKGROUND: The optical needs of most low-vision patients can be satisfied with one or more of a large array of prefabricated, off-the-shelf, handheld or spectacle-mounted devices. When these devices do not provide the expected or desired results, a practitioner has the opportunity to design a custom-made device to satisfy the vision demands of the patient. CASE REPORT: A patient with a history of having tried several devices to see his music while playing the violin was examined and a simple, inexpensive. Galilean telescopic device was formulated, designed, and constructed. The objective was to create a telescope that would provide adequate magnification with a wider field of view than was available with prefabricated devices. The components needed to generate the required magnification were determined using basic telescope design concepts and equations. CONCLUSIONS: For patients with intermediate and/or distance symptoms testing with a telescope is an important part of the low-vision evaluation. Field of view, expense, and the time required to obtain the device are important considerations in deciding what to prescribe. The pathology involved, task demands, time since onset of decreased acuity, and personality of the patient will dictate, to a large degree, the acceptance of the device.

Eyeglasses↗
PubMed1995

Transnasal repair of choanal atresia using telescopes.

OBJECTIVE: Choanal atresia, consisting of a unilateral or bilateral bony or membranous septum between the nose and the pharynx, occurs in approximately one of 7000 live births. Conventional treatment has consisted of watchful observation and elective surgical repair or immediate intervention using a variety of surgical techniques. We attempted transnasal repair using a telescope to remedy the obstruction. PATIENTS: Over an 18-month period, six female and four male patients, who were between 3 weeks and 14 years of age at the time of surgery, underwent transnasal repair of unilateral or bilateral choanal atresia with the aid of a rod-lens telescope. All 10 patients had nasal stents made from endotracheal tubes that were fixed with sublabial and transseptal sutures. RESULTS: Seven patients remain free of symptoms 18 to 24 months after surgery. Three patients required revision surgery. Two of the revision cases recovered completely, with no restenosis 12 months after the second surgery. There were no postoperative complications. CONCLUSION: Transnasal repair of choanal atresia using a rod-lens telescope appears to be an effective procedure with low morbidity.

Adolescent↗
PubMed1999

Long-term result of arterial grafts interposed for arterial defects using the telescoping anastomotic technique: histological and angiographic study.

The arterial grafting model for arterial defects provides an ideal environment for the microvascular telescoping anastomosis because tension of the repaired vessel is maintained low and deformities of the inserted vessel end is minimal due to the thick arterial wall. The left femoral artery was grafted in 46 rats into the defect created in the right femoral artery using the telescoping anastomotic technique at both the proximal and distal anastomoses. The grafts were seen histologically and angiographically 3 to 4 months postoperatively in order to fairly evaluate the telescoping anastomosis in terms of long-term patency, stenosis, and changes in the outer and inner walls at the anastomosis. All arterial grafts were patent 3 to 4 months postoperatively and there were no aneurysms at the anastomoses. Enlargement of the graft diameter was minimal. The rate of stenosis at the anastomosis was smaller than that 1-day postoperatively. Even though the thick arterial wall was initially inserted and the intimal hyperplasia was still present at the anastomosis 3 to 4 months postoperatively, the long-term stenosis was relatively mild due to the atrophy in the overlapped walls.

Anastomosis, Surgical↗
PubMed2000

Multiple telescoping anastomosis on an artery.

The telescoping anastomotic technique was carried out four times on the rat femoral artery in order to examine whether the technique could safely be used three to four times for repair of an artery that was injured at two different sites. In addition, the technique was repeated five and six times to determine the maximum number of anastomosis that could be performed on an artery and to clarify problems of the telescoping anastomosis. In the rats in which the anastomosis was carried out four and five times, 100% patency was obtained, while the first occlusion occurred in a graft on which the anastomosis was repeated six times. The telescoping technique appeared to safely be used three or four times for repair of an artery that had been divided at two sites if tension of the repaired vessel was kept low by the grafting, and torsion of the graft and deformities of the inserted vessel were minimal.

Animals↗
PubMed2005

Forward telescoping bias in reported age of onset: an example from cigarette smoking.

Age at the onset of a disorder is one of its key descriptive characteristics. Early onset may indicate increased risk of a severe course and increased genetic liability. However, retrospectively reported onset in surveys is subject to forward telescoping, a bias in which respondents report events closer to the time of interview than is true. We examined the effect of this bias on age of onset for smoking initiation and daily smoking. Data came from the 1966-77 birth cohorts interviewed in the cross-sectional National Household Surveys on Drug Abuse (NHDSA) 1979-98 (N = 82,122). An association between age at onset and age at interview, within birth year, was found for experimenters and for daily smokers. This was indicative of forward telescoping. As age at interview increased from 12 to 25 the probability of reporting early onset dropped by half. An association was also found between early onset of daily smoking and age at interview. This response bias differed significantly by sex and race, created significant misclassification of smokers as late instead of early onset cases, and biased cohort comparisons from cross-sectional data. These results suggest efforts need to be made to limit the effect of forward telescoping in epidemiological studies by survey question and sampling design.

Adult↗
PubMed2004

Diagnosis of ventilator-associated pneumonia: agreement between quantitative cultures of endotracheal aspiration and plugged telescoping catheter.

OBJECTIVE: To evaluate the diagnostic agreement between quantitative cultures of samples obtained with endotracheal aspiration (ETA) and plugged telescoping catheter (PTC). DESIGN: Prospective study. SETTING: Medical ICU. PATIENTS: Hundred thirty-eight episodes of suspected ventilator-associated pneumonia studied in 100 consecutive patients. INTERVENTIONS: For each suspected episode of ventilator-associated pneumonia, ETA and PTC were performed consecutively. The agreement between microbiological results obtained from the two techniques was evaluated (kappa statistic test). Pneumonia was diagnosed on a positive culture result of telescoping catheter with the threshold set at 10(3) cfu/ml or more. The cut-off points evaluated for ETA ranged from 10(2 )to 10(6) cfu/ml. RESULTS: Micro-organisms retrieved by aspiration and telescoping catheter were similar and bacterial counts obtained by the two procedures were well correlated ( r = 0.71 p < 0.001). There was good agreement between positive and negative ETA and PTC specimens (kappa: 0.78) with a diagnostic threshold for ETA of 10(4) cfu/ml. The sensitivity and specificity of ETA for the diagnosis of PTC-confirmed pneumonia were 92% and 85%, respectively. Kappa decreased to 0.48 when the diagnostic threshold was increased to 10(6) cfu/ml. CONCLUSIONS: Quantitative cultures of ETA and PTC tallied for both micro-organisms and counts. The simpler ETA appears adequate for determining the presence of pathogenic organisms in significant concentration in the lower respiratory tract.

Bacteria↗
PubMed2004

Eight-dimensional methodology for innovative thinking about the case and ethics of the Mount Graham, Large Binocular Telescope project.

This paper introduces the Eight Dimensional Methodology for Innovative Thinking (the Eight Dimensional Methodology), for innovative problem solving, as a unified approach to case analysis that builds on comprehensive problem solving knowledge from industry, business, marketing, math, science, engineering, technology, arts, and daily life. It is designed to stimulate innovation by quickly generating unique "out of the box" unexpected and high quality solutions. It gives new insights and thinking strategies to solve everyday problems faced in the workplace, by helping decision makers to see otherwise obscure alternatives and solutions. Daniel Raviv, the engineer who developed the Eight Dimensional Methodology, and paper co-author, technology ethicist Rosalyn Berne, suggest that this tool can be especially useful in identifying solutions and alternatives for particular problems of engineering, and for the ethical challenges which arise with them. First, the Eight Dimensional Methodology helps to elucidate how what may appear to be a basic engineering problem also has ethical dimensions. In addition, it offers to the engineer a methodology for penetrating and seeing new dimensions of those problems. To demonstrate the effectiveness of the Eight Dimensional Methodology as an analytical tool for thinking about ethical challenges to engineering, the paper presents the case of the construction of the Large Binocular Telescope (LBT) on Mount Graham in Arizona. Analysis of the case offers to decision makers the use of the Eight Dimensional Methodology in considering alternative solutions for how they can proceed in their goals of exploring space. It then follows that same process through the second stage of exploring the ethics of each of those different solutions. The LBT project pools resources from an international partnership of universities and research institutes for the construction and maintenance of a highly sophisticated, powerful new telescope. It will soon mark the erection of the world's largest and most powerful optical telescope, designed to see fine detail otherwise visible only from space. It also represents a controversial engineering project that is being undertaken on land considered to be sacred by the local, native Apache people. As presented, the case features the University of Virginia, and its challenges in consideration of whether and how to join the LBT project consortium.

Arizona↗
PubMed1987

Role of enteric plexuses in the competency of telescoped intestinal valves.

The mechanism of preventing intestinal regurgitation by means of a telescoped intestinal valve has been investigated in this study. Ten telescoped intestinal valves were uniformly created in dogs. A tolerance test to barium reflux was performed before the animals were sacrificed 16 weeks postoperatively, which yielded various barium tolerance values. Statistical analysis revealed that the differences in barium tolerance values in the uniformly constructed valves were closely related to the proportion of the enteric plexuses which contained ganglion cells with normal shapes (r = 0.97, p less than 0.001) and their intestinal segment coverage (r = 0.94, p less than 0.001), but no correlation was found between barium tolerance and the thickness of the valvular musculature (r = 0.04) or the length of the artificial valve (r = 0.39). The results in this study suggest that the intact enteric plexuses play an important role in modulating the competency of the telescoped intestinal valve.

Animals↗
PubMed1981

Telescope retainers for removable partial dentures.

Telescope crowns used in removable partial dentures reduce the destructive horizontal and rotational occlusal forces by directing them more axially and less traumatically than other retainers. These properties are combined with excellent conditions for cross-arch and multiple abutment splinting. If one of the abutment teeth needs extracting, the denture can be repaired with acrylic resin simply by remaking the secondary crown into a pontic. The single copings can be easily cleaned due to the good accessibility around their gingival margins. They also protect the abutment teeth against caries and thermal irritation. Soldering of the primary copings or their connection with accessory bars is not necessary in rigidly constructed telescope crowns, because the secondary crowns incorporated in the superstructure provide sufficient rigidity. In addition, the splinted copings often cause inflammatory gingival hyperplasia because the solder joints are too close to the gingival margins, preventing proper hygiene maintenance. The taper configuration or vertical height of the coping, which determines the amount of load transferred to each abutment, can be planned to suit each tooth's condition and designated function in the restoration. In a fixed restoration, the load is always evenly distributed among all the abutment teeth regardless of their condition, because the crowns are permanently cemented to them. In the telescope denture, the amount of force can be individually regulated by modifying the form and leverage of the retainers, according to their position, bone support, and occlusal conditions.

Crowns↗
PubMed1993

Vein grafting with the telescoping anastomotic technique for venous defects.

The telescoping anastomotic technique was used at both ends of autogenous vein grafts bridging a defect in slow-running, vulnerable veins. This was done on left epigastric veins of the rat, the central part of which was used as a graft. In the right epigastric veins, both the proximal and distal anastomoses were repaired using the conventional anastomotic technique. The overall patency rate of the grafts repaired with the telescoping anastomotic technique was 27/29 (93.3%) compared to 17/28 (60.7%) in the conventional group. The telescoping technique was also easier to perform than the conventional method.

Anastomosis, Surgical↗
PubMed2003

Experimental examination of the healing process of telescopic esophageal anastomosis.

The basis of telescopic anastomosis is old, only the practical details of it have changed and improved. The telescopic anastomosis technique is successfully applied in our practice for reconstruction of gastrectomy and esophageal resection. The reason for this study was that data about the healing process of telescopic anastomosis had not been found in the literature. We used four groups of mongrel dogs for our experiments: Group A (n = 3) received 20 mm-long invaginations with a survival time of 7 days; Group B (n = 3) received 10 mm-long invaginations with a survival time of 21 days; Group C (n = 3) received 20 mm-long invaginations with a survival time of 21 days; Group D (n = 3) received 30 mm-long invaginations with a survival time of 21 days. At the end of the above survival times we removed the anastomosing area, measured the bursting pressures and performed morphological and histological examinations. In each case we also performed an anastomosis exactly the same as a completely healed anastomosis and its pressure tolerance was measured (0 day). The pressure tolerance within the anastomosis rises gradually and independently of the length of the invaginated esophageal part. Anastomosis leakage did not occur. The invaginated esophageal part did not suffer any damage. The muscular wall of the intragastric part of the esophagus became covered by the mucosa of the stomach during the healing process and it joined with the esophageal mucosa at the edge of the free end of the esophagus.

Anastomosis, Surgical↗
PubMed1999

Arterial anastomosis using the telescoping method and an elastomeric adhesive.

We experimentally studied a new technique for anastomosis of small arteries which involves the telescoping method and a surgical adhesive with the objective of examining its clinical potential. This technique was applied to the unilateral femoral arteries of 27 mongrel dogs. After division of the artery, the distal artery was incised longitudinally, and the proximal end was invaginated into the opened artery. One stay suture and the elastomeric adhesive PUP201 were placed in the anastomotic site. The bursting and tensile strength and the patency were examined, and a histopathological study was performed at various intervals up to 1 year after the operation. The bursting strength exceeded 500 mm Hg. The patency rate of the anastomosed arteries was 100%. The mean percentage of stenosis to diameter of the proximal normal lumen was 20% one year after operation. The luminal surface of the anastomosed line was healed smoothly, and thrombi between the telescoped arteries were replaced by elastofibrotic union. In conclusion, small arterial anastomosis using the telescoping method and an elastomeric adhesive is easy and safe and provides good patency.

Anastomosis, Surgical↗