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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Surface micromachined hollow metallic microneedles

Chandrasekaran, Shankar 05 1900 (has links)
No description available.
42

An analysis of opportunities and barriers related to the establishment of safer injection rooms in Canada /

Malowaniec, Leah. January 2000 (has links)
Increasing rates of infectious diseases such as HIV and hepatitis C, overdose deaths, and social concerns around injection drug use have resulted in the need to evaluate new initiatives for harm reduction in Canada. This study examined experts' views on the feasibility of, benefits of, and barriers to the establishment of safer injection rooms in Canada. The qualitative model involved interviews (N = 6) with a range of professionals in the area of addictions. Analysis of the data revealed that there is an urgent need for expanded and improved harm reduction strategies, that safer injection rooms could offer many benefits to Canadians, that several debates exist with regard to the policies and services related to safer injection rooms, and that safer injection rooms, as well as alternative initiatives, must be considered if Canada wishes to promote health among drug users and wider communities. The implications of the findings for social work and further research are discussed. Recommendations include expanded educational initiatives for professionals and the public, intensive research related to the specific Canadian context, and the establishment of a trial protocol.
43

Production, development, and characterization of plastic hypodermic needles

Stellman, Jeffrey Taylor 13 May 2009 (has links)
Plastic hypodermic needles are a potential solution to the problem of disease spread through needle reuse. Plastics could be used to potentially reduce needle reuse as they are easier to destroy than steel. A key issue in their acceptance is the force required to penetrate a patient; a smaller force is associated with less pain. The effect that needle parameters have on the penetration force is studied in an effort to better understand how to reduce penetration forces and increase the success of penetrations for plastic needles. These parameters - geometry, tip radius, diameter, material, and lubricant - are studied through penetration, buckling, and coefficient of friction testing. The tests are conducted on steel needles, which serve as a control group, as well as two varieties of plastic needles. The outcome is a quantitative understanding of the effect that the various parameters have on penetration force, which is used to inform plastic needle design.
44

A comparative study of inclinometers and time domain reflectometry for slope movement analysis

Sargent, Lisa M. January 2004 (has links)
Thesis (M.S.)--Ohio University, March, 2004. / Title from PDF t.p. Includes bibliographical references (leaves 73-75).
45

Stickrädsla och lindrande omvårdnadsåtgärder inom hälso- och sjukvården : en litteraturstudie ur ett patientperspektiv / Fear of needles and soothing caring methodsin health care : a literature review from the patients’ perspective

Ekman, Rebecca, Roth, Marianne January 2014 (has links)
Bakgrund: Ett nålstick kan ses som ett enkelt ingrepp men för somliga kopplas detta till en stark rädsla och oro. Stickrädsla är vanligt förekommande och kan bero på tidigare negativa erfarenheter. Det är sjuksköterskans ansvar att skapa förutsättningar för patienten att hantera sin stickrädsla och tillgodose patientens grundläggande omvårdnadsbehov. Syfte: Syftet med litteraturstudien var att undersöka stickrädsla hos vuxna patienter och deras erfarenheter av lindrande omvårdnadsåtgärder. Metod: En allmän litteraturstudie baserad på fem kvantitativa artiklar, tre kvalitativa och en där båda metoder tillämpats. Resultat: Resultatet innefattar fyra kategorier; Reaktioner vid och inför nålstick; Strategier för att hantera och minimera stickrädsla; Faktorer som förstärker rädslan och Faktorer som minskar rädslan. Slutord: För att patienten ska få en individanpassad vård behöver sjuksköterskan ha kunskap om stickrädsla och lindrande omvårdnadsåtgärder i samband med stick hos vuxna patienter med stickrädsla. / Background: A pinprick from a needle is a fairly simple procedure but to some patients it is linked to strong emotional anxiety and fear. Fear of needles is common and could be due to previous negative experiences. It is the responsibility of the nurse to establish good conditions for patients to deal with their anxiety and to meet their basic needs. Aim: The aim of the study was to study needle fear among adult patients’ and their experiences of soothing caring methods. Method: The study was carried out as a literature review based on five quantitative studies, three qualitative and one which was carried out with both methods. Result: The result consisted of four headings; Reactions related to pinpricks; Strategies to combat and minimize the fear; Contributing factors and Reducing factors. Conclusion: The nurse must have knowledge about needle fear among adult patients and soothing caring methods to enable an individual care.
46

An analysis of opportunities and barriers related to the establishment of safer injection rooms in Canada /

Malowaniec, Leah. January 2000 (has links)
No description available.
47

Microneedles for the inner ear

Aksit, Aykut January 2022 (has links)
The cochlea, or inner ear, is a space fully enclosed within the temporal bone of the skull, except for two membrane-covered portals connecting it to the middle ear space. One of these portals is the round window, which is covered by the Round Window Membrane (RWM). A longstanding clinical goal is to gain reliable and precise access to the cochlea with the purpose of delivering therapeutics to treat a plethora of auditory and vestibular disorders, or to aspirate fluids for diagnostic purposes. Standard of care for several difficult-to-treat diseases calls for injection of a therapeutic substance through the tympanic membrane into the middle ear space, after which a portion of the substance diffuses across the RWM into the cochlea. The efficacy of this technique is limited by an inconsistent rate of molecular transport across the RWM. Other solutions for delivery require either traumatic drilling through the bone of the cochlea, or perforating the delicate RWM, which is prone to rupturing with the use of regular surgical tools. For conducting precision diagnostics, even fewer options exist. In our research group, utilizing a newly available technology called Two-Photon Lithography, (2PP) we have developed a suite of ultra-sharp microneedles that are able to create repeatable and reliable perforations in the RWM without tearing. These holes were seen to spontaneously heal within 48 hours, and did not cause any audiological or functional consequences. Furthermore, we have designed needles that can, while inserted into the cochlea, inject or aspirate fluid of microliter quantities, to and from the inner ear, safely. In this thesis, I will discuss the development of these microneedles: their methods, design, use, and modeling. The results show that the microneedles hold great promise to diagnose and treat hearing and balance disorders.
48

A NOVEL BIOINSPIRED DESIGN FOR SURGICAL NEEDLES TO REDUCE TISSUE DAMAGE IN INTERVENTIONAL PROCEDURES

Sahlabadi, Mohammad January 2018 (has links)
The needle-based procedures are usually considered minimally invasive. However, in insertion into soft tissues such as brain and liver, the tissue damage caused by needle insertion can be very significant. From the literature, it has been known that reduction in needle insertion and extraction forces as well as tissue deformation during the insertion results in less invasive procedure. This work aims to design and develop a new bioinspired design for surgical needles which reduce the insertion and extraction forces of the needle, and its damage to the tissue. Barbs in honeybee stinger decrease its insertion force significantly. Inspired by that finding, a new honeybee-inspired needle was designed and developed, and its insertion mechanics was studied. To study the insertion mechanics of honeybee-inspired needle, insertion tests into artificial and biological tissues were performed using both honeybee-inspired and conventional needles. The barb design parameters effects on needle forces were studied through multiple insertion and extraction tests into PVC gels. The design parameters values of the barbs were experimentally modified to further reduce the ultimate insertion and extraction forces of the needle. Bioinspired needle with modified barb design parameters values reduces the insertion force by 35%, and the extraction force by 20%. To show the relevance, the insertion tests into bovine liver and brain tissue were performed. Our results show that there was a 10-25% decrease in the insertion force for insertions into bovine brain, and a 35-45% reduction in the insertion force for insertions into the bovine liver using the proposed bioinspired needles. The bioinspired and conventional needles were manufactured in different scales and then used to study the size scale effect on our results. To do so, the insertion tests into tissue-mimicking PVC gels and liver tissues were performed. The results obtained for different sizes of the needle showed 25-46% decrease in the insertion force. The tissue deformations study was conducted to measure tissue deformation during the insertion using digital image correlation. The tissue deformation results showed 17% decrease in tissue deformation using barbed needles. A histological study was performed to accurately measure the damage caused by needle insertion. Our results showed 33% less tissue damage using bioinspired needles. The results of the histological study are in agreement with our hypothesis that reducing needle forces and tissue deformation lead to less invasive percutaneous procedures. / Mechanical Engineering
49

Comparative study of an antioxidant defense mechanism in genotypes of eastern white pine which show differential foliar characteristics

Anderson, James V. 16 September 2005 (has links)
Approximately 10-15% of field-grown eastern white pine (Pinus strobus L.) within a nursery plantation expressed foliar characteristics similar to that induced by oxidant pollution. Sensitive genotypes (based on foliar characteristics), had a 50% reduction in needle growth, severe needle tip burn, mottling, and early needle shed during a high O₃, drought-type growing season (1988) compared to a low O₃, non-drought growing season (1989). Tolerant genotypes showed little difference in needle growth or visible injury during the two growing season. Seasonal needle ascorbate concentrations were similar during the two years however, needle glutathione (GSH) content has not. Total GSH content was two-to three-fold greater in both genotypes during the summer of 1989 compared to 1988. Cloned, tolerant trees also had 23% more total GSH when exposed to forced ambient air compared to charcoal-filtered air in open-top chambers. Cloned sensitive trees had similar GSH concentrations when exposed to different chamber treatments. One-year-old needles always had lower ratios of ascorbate/ dehydroascorbate, ascorbate/α-tocopherol and GSH/GSSG than current year needles. One-year-old needles from the tolerant tree also maintained a higher glutathione reductase (GR) activity than the sensitive tree during the late summer. Needles of eastern white pine had two isoforms of GR (GR<sub>A</sub> and GR<sub>B</sub>). GR<sub>A</sub> and GR<sub>B</sub> accounted for 17% and 83% of the GR recovered, respectively. GR<sub>A</sub> and GR<sub>B</sub> had different physical and kinetic properties. Antibody produced from GRR was reactive with both native and denatured GR<sub>B</sub>, but was cross-reactive with only native GR<sub>A</sub>. Tolerant and sensitive clones exposed to control (< 0.025 ppm) or high (4.5 ppm∙hr total dose) O₃ for O to 72 hr, showed no increase in GR activity. Only in the high-O₃-treated trees did the amount of GR protein increase. Needles from the sensitive clone contained 14, 62, and 464 ng GR mgP⁻¹ and needles from the tolerant clone contained 21, 138, and 2800 ng GR mgP⁻¹ after 0, 24 and 72 hr O₃ exposure, respectively. The results of this dissertation indicate that differential foliar characteristics in eastern white pine may be correlated with GSH turnover and its regulation by GR during periods of high oxidant stress. / Ph. D.
50

Comparing the Ignitability of Mulch Materials for a Firewise Landscape

DeGomez, Tom, Rogstad, Alix, Schalau, Jeff, Kelly, Jack 09 1900 (has links)
5 pp. / Eight different landscape mulches were tested for their flammability using a propane torch, charcoal briquette, and a cigarette at two different times of the year. Three randomized compete blocks with eight one square meter plots were tested at three locations; Tucson, Prescott, and Flagstaff, Arizona. Each of the mulches was subjected to the heat of a handheld propane torch (15 seconds), a glowing charcoal briquette (five minutes), and a lit cigarette (until burned out). We found that the least dense mulches (pine needles and straw) burned rapidly when subjected to the torch and ignited after the briquette was removed. The medium density mulches (pine bark nuggets and wood chips) had low flame lengths and smoldered. Heavy density mulches (garden compost and shredded bark) only smoldered. The decomposed granite and sod did not ignite or smolder.

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