302 research outputs found

    Metric Variation on the Arikara Pelvis

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    Metric variation in the innominates, sacra and articulated pelves of the South Dakota Plains Indian group, the Arikara, are analyzed in an attempt to delineate biological relationships. The specimens examined represent 10 archaeological sites ranging in date from A.D. 1600 to 1832. The following sample sizes for innominate, sacrum and articulated pelvis data sets are employed: 292, 305, and 151, respectively. The data are analyzed utilizing univariate as well as multivariate statistical procedures. The results indicate that consistent within-group patterning exists. Common elements of pelvic structure can therefore be identified. Group analysis results indicate that temporal patterning can be identified on the innominate and articulated pelvis. In general, these results are consistent with those of several Arikara craniometric studies. Several explanations, namely obstetrical significance, demographic age structure differences, and gene flow, for the observed patterning are explored. Neither alone, however, appears to completely explain the patterning noted. An analysis of the patterns of sexual dimorphism expressed in the Arikara groups examined indicates that nutritional factors alone are not responsible for the noted patterning. The results tend to more strongly support a greater genetic component to ranging patterns of Arikara sexual dimorphism and are also consistent with the resent results obtained for the Arikara postcranial skeleton. Future studies employing data from other Plains Indians groups are designed to delineate the environmental and genetic components of variation of the boney pelvis as necessary in order to disprove or substantiate the present results. Data collection for this work was supported by NSF Grant BNS 8102650

    Miniaturizing microvias for multi-chip modules

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 63-64).Electronics packaging is continually migrating toward denser packaging. This encompasses a push toward multilevel die, denser metallization, and smaller microvias. In this thesis we investigate the miniaturization of laser-drilled microvias in polyimide dielectric for chips-first multi-chip module (MCM) technology. The challenge is to produce increasingly smaller microvias and package more microvias into a given area without sacrificing electrical performance. Principally, this means a microvia must maintain certain minimum electrical resistance and mechanical adhesion to the conducting layers. The thesis encompasses the following research: 1. Investigating the state of the art in laser-drilled polyimide microvias. 2. Designing and fabricating test structures with microvias, in which the state of the art is pushed in microvia size and/or aspect ratio. 3. Measuring the contact resistances of laser-drilled microvias in a Kelvin structure configuration. 4. Developing finite element models of Kelvin structures to estimate the contact resistance of miniature microvias.The experimental results of this thesis prove that microvias with approximately 19 pm diameter and 10 mQ contact resistance can be reliably fabricated for chips-first MCM technology.by Paul Gerard Puskarich.M.Eng

    An improved sigma-delta modulator for digitizing carrier band measurements

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (p. 97-99).Draper Laboratory currently employs a third-order Sigma-Delta modulator to digitize the outputs from microelectromechanical sensors at the intermediate frequency prior to demodulation inside a field programmable gate array. This modulator, which is built on a .5[mu]m CMOS process, is to be used as a standalone chip or as a core for use in larger microelectromechanical sensor integrated circuits. In this document, I submit the design of an improved Sigma-Delta modulator, which has a noise floor of 40nV/ [square root of] Hz and a 5Vpp input range.by John Gerard Puskarich.M.Eng

    Development of a clinical teaching evaluation and feedback tool for faculty

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    Copyright © 2019 by The American Society for Pharmacology and Experimental Therapeutics. Sigma-2 receptors, recently identified as TMEM97, have been implicated in cancer and neurodegenerative disease. Structurally distinct sigma-2 receptor ligands induce cell death in tumor cells, linking sigma-2 receptors to apoptotic pathways. Recently, we reported that sigma-2 receptors can also stimulate glycolytic hallmarks, effects consistent with a prosurvival function and upregulation in cancer cells. Both apoptotic and metabolically stimulative effects were observed with compounds related to the canonical sigma-2 antagonist SN79. Here we investigate a series of 6-substituted SN79 analogs to assess the structural determinants governing these divergent effects. Substitutions on the benzoxazolone ring of the core SN79 structure resulted in high-affinity sigma-2 receptor ligands (Ki 5 0.56–17.9 nM), with replacement of the heterocyclic oxygen by N-methyl (producing N-methylbenzimidazolones) generally decreasing sigma-1 affinity and a sulfur substitution (producing benzothiazolones) imparting high affinity at both subtypes, lowering subtype selectivity. Substitution at the 6-position with COCH3, NO2, NH2, or F resulted in ligands that were not cytotoxic. Five of these ligands induced an increase in metabolic activity, as measured by increased reduction of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetra-zolium bromide) in human SK-N-SH neuroblastoma cells, further supporting a role for sigma-2 receptors in metabolism. Substitution with 6-isothiocyanate resulted in ligands that were sigma-2 selective and that irreversibly bound to the sigma-2 receptor, but not to the sigma-1 receptor. These ligands induced cell death upon both acute and continuous treatment (EC50 5 7.6–32.8 mM), suggesting that irreversible receptor binding plays a role in cytotoxicity. These ligands will be useful for further study of these divergent roles of sigma-2 receptors

    Whole blood lactate kinetics in patients undergoing quantitative resuscitation for septic shock

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    Introduction We sought to compare the association of whole blood lactate kinetics with survival in patients with septic shock undergoing early quantitative resuscitation. Methods Preplanned analysis of a multicenter emergency department (ED)-based randomized control trial of early sepsis resuscitation targeting three physiological variables: central venous pressure, mean arterial pressure, and either central venous oxygen saturation or lactate clearance. Inclusion criteria: suspected infection, two or more systemic inflammatory response syndrome criteria, and either SBP 4 mmol/l. All patients had a lactate measured initially and subsequently at two hours. Normalization of lactate was defined as a lactate decline to 2.0 mmol/l was seen in 187/272 (69%), and 68/187 (36%) patients normalized their lactate. Overall mortality was 19.7%. AUCs for initial lactate, relative lactate clearance, and absolute lactate clearance were 0.70, 0.69, and 0.58, respectively. Lactate normalization best predicted survival (OR = 6.1, 95% CI = 2.2 to 21), followed by lactate clearance of 50% (OR = 4.3, 95% CI = 1.8 to 10.3), initial lactate of <2 mmol/l (OR = 3.4, 95% CI = 1.5 to 7.8), and initial lactate <4 mmol/l (OR = 2.3, 95% CI = 1.3 to 4.3), with lactate clearance of 10% not reaching significance (OR = 2.3, 95% CI = 0.96 to 5.6). Conclusions In ED sepsis patients undergoing early quantitative resuscitation, normalization of serum lactate during resuscitation was more strongly associated with survival than any absolute value or absolute/ relative change in lactate. Further studies should address whether strategies targeting lactate normalization leads to improved outcomes

    Effect of Glucose–Insulin–Potassium Infusion on Mortality in Critical Care Settings: A Systematic Review and Meta-Analysis

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    This study seeks to measure the treatment effect of glucose—insulin—potassium (GIK) infusion on mortality in critically ill patients. A systematic review of randomized controlled trials is conducted, comparing GIK treatment with standard care or placebo in critically ill adult patients. The primary outcome variable is mortality. Two authors independently extract data and assess study quality. The primary analysis is based on the random effects model to produce pooled odds ratios (ORs) with 95% confidence intervals (CIs). The search yields 1720 potential publications; 23 studies are included in the final analysis, providing a sample of 22 525 patients. The combined results demonstrate no heterogeneity (P = .57, I2 = 0%) and no effect on mortality (OR = 1.02; 95% CI, 0.93–1.11) with GIK treatment. No experimental studies of shock or sepsis populations are identified. This meta-analysis finds that there is no mortality benefit to GIK infusion in critically ill patients; however, study populations are limited to acute myocardial infarction and cardiovascular surgery patients. No studies are identified using GIK in patients with septic shock or other forms of circulatory shock, providing an absence of evidence regarding the effect of GIK as a therapy in patients with shock

    COVID‐19: The Uninvited Guest in the Intensive Care Unit — Implications for Pharmacotherapy

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155543/1/phar2394.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155543/2/phar2394_am.pd

    Plasma Levels of Mitochondrial DNA in Patients Presenting to the Emergency Department with Sepsis

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    Introduction Elevated levels of plasma mitochondrial DNA (mtDNA) have been reported in trauma patients, and may contribute to the systemic immune response. We sought to determine the plasma levels of mtDNA in emergency department (ED) patients with and without sepsis and evaluate their association with severity of illness. Methods Prospective observational study of patients presenting to one of three large, urban, tertiary care EDs. Patients were enrolled into one of three cohorts: 1) sepsis defined as suspected infection and two or more SIRS criteria without hypotension; 2) septic shock defined as sepsis plus hypotension despite an adequate fluid challenge; and 3) control defined as non-infected ED patients without SIRS/hypotension. Plasma levels of three mtDNAs were measured using real-time quantitative PCR. Levels of mtDNAs were compared between the three cohorts and linear regression was used to assess the association between mtDNAs, IL-6, IL-10, and sequential organ failure assessment (SOFA) scores in patients with sepsis. Results We enrolled 93 patients: 24 controls, 29 with sepsis, and 40 with septic shock. As expected, co-morbidities and SOFA score increased across categories. We found no difference in mtDNA levels between the three groups (p = 0.14-0.30). Among patients with sepsis, we found a small but significant negative association between mtDNA level and SOFA score, most clearly with cytochrome b (p=0.03). Conclusions We found no difference in mtDNA levels between controls and patients with sepsis. mtDNA levels were negatively associated with organ dysfunction, suggesting that plasma mtDNA does not significantly contribute to the pathophysiology of sepsis

    Association Between Early Hyperoxia Exposure After Resuscitation From Cardiac Arrest and Neurological Disability: Prospective Multicenter Protocol-Directed Cohort Study

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    BACKGROUND: Studies examining the association between hyperoxia exposure after resuscitation from cardiac arrest and clinical outcomes have reported conflicting results. Our objective was to test the hypothesis that early postresuscitation hyperoxia is associated with poor neurological outcome. METHODS: This was a multicenter prospective cohort study. We included adult patients with cardiac arrest who were mechanically ventilated and received targeted temperature management after return of spontaneous circulation. We excluded patients with cardiac arrest caused by trauma or sepsis. Per protocol, partial pressure of arterial oxygen (Pao2) was measured at 1 and 6 hours after return of spontaneous circulation. Hyperoxia was defined as a Pao2 >300 mm Hg during the initial 6 hours after return of spontaneous circulation. The primary outcome was poor neurological function at hospital discharge, defined as a modified Rankin Scale score >3. Multivariable generalized linear regression with a log link was used to test the association between Pao2 and poor neurological outcome. To assess whether there was an association between other supranormal Pao2 levels and poor neurological outcome, we used other Pao2 cut points to define hyperoxia (ie, 100, 150, 200, 250, 350, 400 mm Hg). RESULTS: Of the 280 patients included, 105 (38%) had exposure to hyperoxia. Poor neurological function at hospital discharge occurred in 70% of patients in the entire cohort and in 77% versus 65% among patients with versus without exposure to hyperoxia respectively (absolute risk difference, 12%; 95% confidence interval, 1-23). Hyperoxia was independently associated with poor neurological function (relative risk, 1.23; 95% confidence interval, 1.11-1.35). On multivariable analysis, a 1-hour-longer duration of hyperoxia exposure was associated with a 3% increase in risk of poor neurological outcome (relative risk, 1.03; 95% confidence interval, 1.02-1.05). We found that the association with poor neurological outcome began at ≥300 mm Hg. CONCLUSIONS: Early hyperoxia exposure after resuscitation from cardiac arrest was independently associated with poor neurological function at hospital discharge

    Randomized trial of inhaled nitric oxide to treat acute pulmonary embolism: The iNOPE trial

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    BACKGROUND: The study hypothesis is that administration of inhaled nitric oxide (NO) plus oxygen to subjects with submassive pulmonary embolism (PE) will improve right ventricular (RV) systolic function and reduce RV strain and necrosis, while improving patient dyspnea, more than treatment with oxygen alone. METHODS: This article describes the rationale and protocol for a registered (NCT01939301), nearly completed phase II, 3-center, randomized, double-blind, controlled trial. Eligible patients have pulmonary imaging-proven acute PE. Subjects must be normotensive, and have RV dysfunction on echocardiography or elevated troponin or brain natriuretic peptide and no fibrinolytics. Subjects receive NO plus oxygen or placebo for 24 hours (±3 hours) with blood sampling before and after treatment, and mandatory echocardiography and high-sensitivity troponin posttreatment to assess the composite primary end point. The sample size of N=78 was predicated on 30% more NO-treated patients having a normal high-sensitivity troponin (<14 pg/mL) and a normal RV on echocardiography at 24 hours with α=.05 and β=.20. Safety was ensured by continuous spectrophotometric monitoring of percentage of methemoglobinemia and a predefined protocol to respond to emergent changes in condition. Blinding was ensured by identical tanks, software, and physical shielding of the device display and query of the clinical care team to assess blinding efficacy. RESULTS: We have enrolled 78 patients over a 31-month period. No patient has been withdrawn as a result of a safety concern, and no patient has had a serious adverse event related to NO. CONCLUSIONS: We present methods and a protocol for the first double-blinded, randomized trial of inhaled NO to treat PE
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