23 research outputs found
Ratio of height to thyromental distance as a predictor of difficult laryngoscopy: A prospective observational study
No full textBackground and Aim: Various airway indices are used either singly or in combination to predict difficult laryngoscopy. Recently introduced ratio of height to thyromental distance (RHTMD) is reported to have better predictability. We aimed to assess the prediction of difficult laryngoscopy by RHTMD and compared it with other indices.
Material and Methods: In this prospective, single-blinded comparative observational study, 300 adult patients of either gender scheduled to receive general anesthesia were assessed. Airway indices, like RHTMD, thyromental distance, modified Mallampati test, and upper lip bite test, were assessed and correlated with Cormack and Lehane's laryngoscopic grading. The validity parameters like specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for each test. Effect of combining all the indices was also analyzed. Receiver operating characteristic curves were constructed and optimal cutoff value for the quantitative indices was calculated.
Results: The incidence of difficult laryngoscopy in our study was 5.33%. Of the four indices, the single best test was RHTMD, with better sensitivity, high specificity, NPV, and accuracy and with good PPV. A combination of all the indices resulted in 100% sensitivity and higher specificity.
Conclusions: RHTMD is a single best preoperative test for predicting difficult laryngoscopy. A combination of tests has higher sensitivity and specificity with better discriminative power. Therefore indices should be used in combination in the preoperative airway assessment of adult patients
Comparison of ultrasound-guided bilateral subcostal transversus abdominis plane block and port-site infiltration with bupivacaine in laparoscopic cholecystectomy
No full textBackground and Aims: Many patients experience moderate-to-severe pain after laparoscopic cholecystectomy. We aimed to compare the efficacy of ultrasound-guided bilateral subcostal transversus abdominis plane (TAP) block with port-site infiltration for post-operative analgesia after laparoscopic cholecystectomy. Methods: Patients undergoing elective laparoscopic cholecystectomy under general anaesthesia were divided into two groups of 40 each to receive ultrasound-guided bilateral subcostal TAP block (T) with 0.25% bupivacaine 20 ml each side or port-site infiltration with 0.5% bupivacaine 5 ml each at 4 ports (I) at the end of the surgery before extubation. All patients received paracetamol 1 g intravenous 8th hourly. Tramadol 1 mg/kg intravenous bolus and diclofenac 1 mg/kg intravenous infusion were used as the first- and second-line rescue analgesics when Numerical Rating Scale (NRS) ≥4, or when the patient complained of pain. NRS at 1, 2, 3, 6, 12 and 24 h after surgery, time to first analgesic request and total dose of analgesics in 24 h were recorded. Chi-square test and independent t-test were used to compare qualitative and quantitative data, respectively. Results: Time to first analgesic (mean±SD) in Group I and Group T was 292.7 ± 67.03 and 510.3 ± 154.55 min and mean tramadol required was141.8 ± 60.01 mg and 48.69 ± 36.14 mg, respectively (P = 0.001 for both). Mean NRS at 2, 3, 6, 12 and 24 h was significantly lower in Group T. Conclusion: Ultrasound-guided bilateral subcostal TAP block provides superior post-operative analgesia after laparoscopic cholecystectomy compared to port-site infiltration
Similarity Metrics Applied to Graph Based Design Model Authoring
No full textModel reuse is typically facilitated by search and retrieval tools, matching the sought model with models in a database. This research aims at providing similar assistance to users authoring design exemplars, a data structure to represent parametric and geometric design problems. The design exemplar represents design problems in the form of a bi-partite graph consisting of entities and relations. Authoring design exemplars for relatively complex design problems can be time consuming and error prone. This forms the motivation of developing a search and retrieval tool, capable of retrieving exemplars that are similar to the exemplar that a user is trying to author, from a database of previously authored exemplars. In order to develop such a tool, similarity measures have been developed to evaluate the similarity between the exemplar that a user is trying to author and target exemplars in the database. Two exemplars can be considered similar based on the number and types of entities and relations shared by them. However, exemplars meant for th
Growth, optical, ICP and thermal studies of nonlinear optical single crystal: Sodium acid phthalate (NaAP)
No full textTeaching functions of a head nurse in training institutions
No full textThesis (M.S.)--Boston UniversityPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at [email protected]. Thank you.2999-01-0
SIMILARITY METRICS APPLIED TO GRAPH BASED DESIGN MODEL AUTHORING
No full textModel reuse is typically facilitated by search and retrieval tools, matching the sought model with models in a database. This research aims at providing similar assistance to users authoring design exemplars, a data structure to represent parametric and geometric design problems. The design exemplar represents design problems in the form of a bi-partite graph consisting of entities and relations. Authoring design exemplars for relatively complex design problems can be time consuming and error prone. This forms the motivation of developing a search and retrieval tool, capable of retrieving exemplars that are similar to the exemplar that a user is trying to author, from a database of previously authored exemplars. In order to develop such a tool, similarity measures have been developed to evaluate the similarity between the exemplar that a user is trying to author and target exemplars in the database. Two exemplars can be considered similar based on the number and types of entities and relations shared by them. However, exemplars meant for the same purpose can be authored using different entities and relations. Hence, the two main challenges in developing a search and retrieval tool are to evaluate the similarity between exemplars based on structure and semantics. In this research, four distinct similarity metrics are developed to evaluate the structural similarity between exemplars for exemplar retrieval: entity similarity, relation similarity, attribute similarity, and graph matching similarity. As well, a thorough understanding of semantics in engineering design has been developed. Different types of semantic information found in engineering design have been identified and classified. Design intent and rationale have been proposed as the two main types of semantic information necessary to evaluate the semantic similarity between exemplars. The semantic and structural similarity measures have been implemented as separate modules in an interactive modeling environment. Several experiments have been conducted in order to evaluate the accuracy and effectiveness of the proposed similarity measures. It is found that for most queries, the semantic retrieval module retrieves exemplars that are not retrieved by structural retrieval module and vice versa
Engineered nanomaterials:Knowledge gaps in fate, exposure, toxicity, and future directions
No full textThe aim of this study is to identify current knowledge gaps in fate, exposure, and toxicity of engineered nanomaterials (ENMs), highlight research gaps, and suggest future research directions. Humans and other living organisms are exposed to ENMs during production or use of products containing them. To assess the hazards of ENMs, it is important to assess their physiochemical properties and try to relate them to any observed hazard. However, the full determination of these relationships is currently limited by the lack of empirical data. Moreover, most toxicity studies do not use realistic environmental exposure conditions for determining dose-response parameters, affecting the accurate estimation of health risks associated with the exposure to ENMs. Regulatory aspects of nanotechnology are still developing and are currently the subject of much debate. Synthesis of available studies suggests a number of open questions. These include (i) developing a combination of different analytical methods for determining ENM concentration, size, shape, surface properties, and morphology in different environmental media, (ii) conducting toxicity studies using environmentally relevant exposure conditions and obtaining data relevant to developing quantitative nanostructure-toxicity relationships (QNTR), and (iii) developing guidelines for regulating exposure of ENMs in the environment.</p
Particle mixing, two level systems and gauge theory
No full text2010 - 2011In this thesis I will discuss the theory of two level systems and the theory
of the oscillating particles in quantum eld theory.
In the rst chapter I will consider the time evolution of a two level system,
a qubit, to show that it has inside a local in time gauge invariant evolution
equation. I construct the covariant derivative operator and show that it is
related to the free energy. The gauge invariance of the time evolution of the
two level system is analogous to the phenomenon of birefringence.I also show
that the two level systems present a Berry-like and an Anandan-Aharonov
phase. Finally, I discuss entropy environment e ects and the distance in
projective Hilbert space between two level states to show that the last one
is properly related to the Aharonov - Anandan phase.
In the second chapter I review the result obtained in QFT for particle mix-
ing, analyzing the theoretical construction and the oscillation formula in the
fermion case.I will emphasize the di erences between the quantum mechan-
ics formulas and the QFT formulas.The unitary inequivalence between the
avor and the mass eigenstates is also shown and the structure of the current
for charged elds is nally discussed. I found a non - perturbative vacuum
structure for the mixing particles that, among the other things, will lead to
a non zero contribution to the value of the cosmological constant (chapter
3).
Several links between rst and second chapter will arise from this thesis and
will shed the light on the fact that it is possible to construct a generic two
level quantum eld theory, that is an extension of the quantum mechanics
bit theory in a quantum eld theory framework. [edited by Author]X n.s
Synthesis of TiO2/WO3 nanoparticles via sonochemical approach for the photocatalytic degradation of methylene blue under visible light illumination
No full textThrough an ultrasound assisted method, TiO2/WO3 nanoparticles were synthesized at room temperature. The XRD pattern of as-prepared TiO2/WO3 nanoparticles matches well with that of pure monoclinic WO3 and rutile TiO2 nanoparticles. TEM images show that the prepared TiO2/WO3 nanoparticles consist of mixed square and hexagonal shape particles about 8–12 nm in diameter. The photocatalytic activity of TiO2/WO3 nanoparticles was tested for the degradation of a wastewater containing methylene blue (MB) under visible light illumination. The TiO2/WO3 nanoparticles exhibits a higher degradation rate constant (6.72 × 10−4 s−1) than bare TiO2 nanoparticles (1.72 × 10−4 s−1) under similar experimental conditions.The author S.A. and T.S. thanks MOEF, New Delhi for the sanction of major research fund (MOEF reference No. 19-26/2009-RE dated 29th March, 2012). The author, S.A. also thanks DST, New Delhi for the sanction of India–Spain collaborative research grant (DST/INT/Spain/P-37/11 dt.16th Dec 2011). T.L.V. thanks the Generalitat Valenciana for the financial support through ACOMP/2013/076. Also, S.A. thank DST for sanctioning FIST (SR/FST/CSI-190/2008 dated 16th March 2009) project
