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排序方式: 共有1037条查询结果,搜索用时 15 毫秒
1.
Devin V Amin Takeo Kanade Anthony M DiGioia Branislav Jaramaz 《Computer aided surgery》2003,8(1):1-16
OBJECTIVE: To allow non-invasive registration of the bone surface for computer-assisted surgery (CAS), this investigation reports the development and evaluation of intraoperative registration using 2D ultrasound (US) images. This approach employs automatic segmentation of the bone surface reflection from US images tagged with the 3D position to enable the application of CAS to minimally invasive procedures. METHODS: The US-based registration method was evaluated in comparison to point-based registration, which is the predominant method in current clinical use. The absolute accuracy of the US-based registration was determined using a phantom pelvis, with fiducial registration providing the ground truth. The relative accuracy was determined by an intraoperative study comparing the US registration to the point-based registration obtained as part of the HipNav experimental protocol. RESULTS: The phantom pelvis study demonstrated equivalent accuracy between point- and US-based registration under in vitro conditions. In the intraoperative study, the US-based registration was sufficiently consistent with the point-based registration to warrant larger-scale clinical trials of this non-invasive registration method. CONCLUSION: Ultrasound-based registration eliminates the need for physical contact with the bone surface as in point-based registration. As a result, non-invasive registration could fully unlock the potential of computer-assisted surgery, enabling development of the next generation of minimally invasive surgical procedures. 相似文献
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Embargoes and sanctions are tools of foreign policy. They can induce a decline in economic activity in addition to reducing imports and untoward health effects can supervene, especially among older persons and those with chronic illnesses. Often, violations of the rights of life, health, social services, and protection of human dignity occur among innocent civilians in embargoed nations. This paper examines the effects of embargoes and sanctions against several nations, and calls for studies to determine ways in which economic warfare might be guided by the rule of humanitarian international law, to reduce the effects on civilians. It suggests that the ability to trade in exempted goods and services should be improved, perhaps by establishing uniform criteria and definitions for exemptions, operational criteria under which sanctions committees might function, and methods for monitoring the impact of sanctions on civilian populations in targeted states, particularly with regard to water purity, food availability, and infectious-disease control. Prospective studies are advocated, to generate the data needed to provide better information and monitoring capacity than presently exists. 相似文献
4.
Large-scale variation among human and great ape genomes determined by array comparative genomic hybridization 总被引:6,自引:1,他引:6
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Locke DP Segraves R Carbone L Archidiacono N Albertson DG Pinkel D Eichler EE 《Genome research》2003,13(3):347-357
Large-scale genomic rearrangements are a major force of evolutionary change and the ascertainment of such events between the human and great ape genomes is fundamental to a complete understanding of the genetic history and evolution of our species. Here, we present the results of an evolutionary analysis utilizing array comparative genomic hybridization (array CGH), measuring copy-number gains and losses among these species. Using an array of 2460 human bacterial artificial chromosomes (BACs) (12% of the genome), we identified a total of 63 sites of putative DNA copy-number variation between humans and the great apes (chimpanzee, bonobo, gorilla, and orangutan). Detailed molecular characterization of a subset of these sites confirmed rearrangements ranging from 40 to at least 175 kb in size. Surprisingly, the majority of variant sites differentiating great ape and human genomes were found within interstitial euchromatin. These data suggest that such large-scale events are not restricted solely to subtelomeric or pericentromeric regions, but also occur within genic regions. In addition, 5/9 of the verified variant sites localized to areas of intrachromosomal segmental duplication within the human genome. On the basis of the frequency of duplication in humans, this represents a 14-fold positional bias. In contrast to previous cytogenetic and comparative mapping studies, these results indicate extensive local repatterning of hominoid chromosomes in euchromatic regions through a duplication-driven mechanism of genome evolution. 相似文献
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Summary The phenotypic trait starry colony in Saccharomyces is associated with a high spontaneous rho
–
petite mutability. Genetic analysis of this trait has shown the high rho
– mutability to be caused by several modifying genes present together in the strains studied. Every single modifying gene produces only a relatively small enhancement of the rho
– mutability. 相似文献
6.
David K. C. Cooper Hidetaka Hara Hayato Iwase Takayuki Yamamoto Zheng‐Yu Wang Abhijit Jagdale Mohamed H. Bikhet Huy Q. Nguyen Jeremy B. Foote Wayne D. Paris David Ayares Vineeta Kumar Douglas J. Anderson Jayme E. Locke Devin E. Eckhoff 《Clinical transplantation》2021,35(1):e14139
Pig organ xenotransplantation offers a solution to the shortage of deceased human organs for transplantation. The pathobiological response to a pig xenograft is complex, involving antibody, complement, coagulation, inflammatory, and cellular responses. To overcome these barriers, genetic manipulation of the organ‐source pigs has largely been directed to two major aims—(a) deletion of expression of the known carbohydrate xenoantigens against which humans have natural (preformed) antibodies, and (b) transgenic expression of human protective proteins, for example, complement‐ and coagulation‐regulatory proteins. Conventional (FDA‐approved) immunosuppressive therapy is unsuccessful in preventing an adaptive immune response to pig cells, but blockade of the CD40:CD154 costimulation pathway is successful. Survival of genetically engineered pig kidneys in immunosuppressed nonhuman primates can now be measured in months. Non‐immunological aspects, for example, pig renal function, a hypovolemia syndrome, and rapid growth of the pig kidney after transplantation, are briefly discussed. We suggest that patients on the wait‐list for a deceased human kidney graft who are unlikely to receive one due to long waiting times are those for whom kidney xenotransplantation might first be considered. The potential risk of infection, public attitudes to xenotransplantation, and ethical, regulatory, and financial aspects are briefly addressed. 相似文献
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Alejandro Azofeifa Diana Valencia Carmen J. Rodriguez Maritza Cruz Devin Hayes Edn Montaez-Bez Betzaida Tejada-Vera Joshua E. Villafae-Delgado Jessica J. Cabrera Miguel Valencia-Prado 《Public health reports (Washington, D.C. : 1974)》2021,136(3):354
ObjectivesUsing the Council of State and Territorial Epidemiologists (CSTE) classification guidelines, we characterized coronavirus disease 2019 (COVID-19)–associated confirmed and probable deaths in Puerto Rico during March–July 2020. We also estimated the total number of possible deaths due to COVID-19 in Puerto Rico during the same period.MethodsWe described data on COVID-19–associated mortality, in which the lower bound was the sum of confirmed and probable COVID-19 deaths and the upper bound was excess mortality, estimated as the difference between observed deaths and average expected deaths. We obtained data from the Puerto Rico Department of Health COVID-19 Mortality Surveillance System, the Centers for Disease Control and Prevention’s National Electronic Disease Surveillance System Base System, and the National Center for Health Statistics.ResultsDuring March–July 2020, 225 COVID-19–associated deaths were identified in Puerto Rico (119 confirmed deaths and 106 probable deaths). The median age of decedents was 73 (interquartile range, 59-83); 60 (26.7%) deaths occurred in the Metropolitana region, and 140 (62.2%) deaths occurred among men. Of the 225 decedents, 180 (83.6%) had been hospitalized and 93 (41.3%) had required mechanical ventilation. Influenza and pneumonia (48.0%), sepsis (28.9%), and respiratory failure (27.1%) were the most common conditions contributing to COVID-19 deaths based on death certificates. Based on excess mortality calculations, as many as 638 COVID-19–associated deaths could have occurred during the study period, up to 413 more COVID-19–associated deaths than originally reported.ConclusionsIncluding probable deaths per the CSTE guidelines and monitoring all-cause excess mortality can lead to a better estimation of COVID-19–associated deaths and serve as a model to enhance mortality surveillance in other US jurisdictions. 相似文献
10.
Saniya S. Godil Scott L. Parker Scott L. Zuckerman Stephen K. Mendenhall Clinton J. Devin Anthony L. Asher Matthew J. McGirt 《The spine journal》2013,13(9):1006-1012
Background contextGiven the unsustainable costs of the US health-care system, health-care purchasers, payers, and hospital systems are adopting the concept of value-based purchasing by shifting care away from low-quality providers or hospitals. Legislation now allows public reporting of these quality rankings. True measures of quality, such as surgical morbidity and validated questionnaires of effectiveness, are burdensome and costly to collect. Hence, patients' satisfaction with care has emerged as a commonly used metric as a proxy for quality because of its feasibility of collection. However, patient satisfaction metrics have yet to be validated as a measure of overall quality of surgical spine care.PurposeWe set out to determine whether patient satisfaction is a valid measure of safety and effectiveness of care in a prospective longitudinal spine registry.Study designProspective longitudinal cohort study.Patient populationAll patients undergoing elective spine surgery for degenerative conditions over a 6-month period at a single medical center.Outcome measuresPatient-reported outcome instruments (numeric rating scale [NRS], Oswestry disability index [ODI], neck disability index [NDI], short-form 12-item survey [SF-12], Euro-Qol-5D [EQ-5D], Zung depression scale, and Modified Somatic Perception Questionnaire [MSPQ] anxiety scale), return to work, patient satisfaction with outcome, and patient satisfaction with provider care.MethodsAll patients undergoing elective spine surgery for degenerative conditions over a 6-month period at a single medical center were enrolled into a prospective longitudinal registry. Data collected on all patients included demographics, disease characteristics, treatment variables, readmissions/reoperations, and all 90-day surgical morbidity. Patient-reported outcome instruments (NRS, ODI, NDI, SF-12, EQ-5D, Zung depression scale, and MSPQ anxiety scale), return to work, patient satisfaction with outcome, and patient satisfaction with provider care were recorded at baseline and 3 months after treatment. Receiver-operating characteristic (ROC) curve analysis was performed to determine whether extent of improvement in quality of life (SF-12 physical component summary [PCS]) and disability (ODI/NDI) accurately predicted patient satisfaction versus dissatisfaction. Standard interpretation of area under the curve (AUC) was used: less than 0.7, poor; 0.7 to 0.8, fair; and greater than 0.8, good accuracy. Multivariate logistic regression analysis was performed to determine if surgical morbidity (quality) or improvement in disability and quality of life (effectiveness of care) were independently associated with patient satisfaction.ResultsFour hundred twenty-two (84%) patients completed all questionnaires 3 months after surgery during the reviewed time period (mean age 55±14 years). Lumbar surgery was performed in 287 (68%) and cervical surgery in 135 (32%) patients. There were 51 (12.1%) 90-day complications, including 21 (5.0%) readmissions and 12 (2.8%) return to operating room. Three hundred fifty-eight (84.8%) patients were satisfied with provider care and 288 (68.2%) with their outcome. Satisfaction with provider care: In ROC analyses, extent of improvement in quality of life (SF-12) and disability (ODI/NDI) differentiated satisfaction versus dissatisfaction with care with very poor accuracy (AUC 0.49–0.69). In regression analysis, 3-month morbidity (odds ratio [95% confidence interval]: 1.45 [0.79–2.66]), readmission (0.66 [0.24–1.80]), improvement in quality of life (SF-12 PCS), or improvement in general health (health transition index) were not associated with satisfaction with care. Satisfaction with outcome: In ROC analyses, improvement in quality of life (SF-12) and disability (ODI/NDI) failed to differentiate satisfaction with good accuracy (AUC 0.76). Neither 90-day morbidity (1.05 [0.46–2.34]) nor 90-day readmission (0.27 [0.04–2.04]) was associated with satisfaction with outcome in regression analysis.ConclusionsPatient satisfaction is not a valid measure of overall quality or effectiveness of surgical spine care. Patient satisfaction metrics likely represent the patient's subjective contentment with health-care service, a distinct aspect of care. Satisfaction metrics are important patient-centered measures of health-care service but should not be used as a proxy for overall quality, safety, or effectiveness of surgical spine care. 相似文献