645 research outputs found
Robust H Stabilization via Parameterized Lyapunov Bounds
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57850/1/RobustHinfStabilizationTAC1997.pd
Ignition of thermally sensitive explosives between a contact surface and a shock
The dynamics of ignition between a contact surface and a shock wave is investigated using a
one-step reaction model with Arrhenius kinetics. Both large activation energy asymptotics and
high-resolution finite activation energy numerical simulations are employed. Emphasis is on comparing
and contrasting the solutions with those of the ignition process between a piston and a shock,
considered previously. The large activation energy asymptotic solutions are found to be qualitatively
different from the piston driven shock case, in that thermal runaway first occurs ahead of
the contact surface, and both forward and backward moving reaction waves emerge. These waves
take the form of quasi-steady weak detonations that may later transition into strong detonation
waves. For the finite activation energies considered in the numerical simulations, the results are
qualitatively different to the asymptotic predictions in that no backward weak detonation wave
forms, and there is only a weak dependence of the evolutionary events on the acoustic impedance
of the contact surface. The above conclusions are relevant to gas phase equation of state models.
However, when a large polytropic index more representative of condensed phase explosives is used,
the large activation energy asymptotic and finite activation energy numerical results are found to
be in quantitative agreement
Robust Controller Synthesis via Shifted Parameter-Dependent Quadratic Cost Bounds
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57848/1/ShiftedParDepTAC1998.pd
Meigs’ syndrome: how we mistook the diagnosis in a tertiary oncology centre in India; an opinion piece on the surgeon’s responsibility in minimizing the stress of the cancer patient and family
Typical Meigs syndrome may mislead the surgeon as advanced ovarian cancer. CECT can identify the huge ovarian mass, ascites and pleural effusion. Mostly Surgeon’s mind focuses towards the pleural effusion with elevated CA 125 as stage IVa ovarian cancer because of the rarity of this syndrome. But it is Surgeon’s responsibility to diagnosis of Meigs syndrome beforehand to alleviate the pain of the patient and her family. Meigs’ syndrome typically presents with the triad of an ovarian mass, ascites and pleural effusion. The latter two resolved after removal of the mass. As this syndrome is a rare entity, this presentation of an ovarian mass may mislead the surgeon, biasing his or her mind towards advanced ovarian malignancy. Along with these if the CA-125 is also raised, the patient is usually labelled as stage IVa ovarian cancer, causing immense distress to the patient and family. This makes it even more imperative that the surgeon diagnoses this syndrome beforehand to avoid the pain of the patient and family
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Polymicrobial periodontal disease triggers a wide radius of effect and unique virome.
Periodontal disease is a microbially-mediated inflammatory disease of tooth-supporting tissues that leads to bone and tissue loss around teeth. Although bacterially-mediated mechanisms of alveolar bone destruction have been widely studied, the effects of a polymicrobial infection on the periodontal ligament and microbiome/virome have not been well explored. Therefore, the current investigation introduced a new mouse model of periodontal disease to examine the effects of a polymicrobial infection on periodontal ligament (PDL) properties, changes in bone loss, the host immune response, and the microbiome/virome using shotgun sequencing. Periodontal pathogens, namely Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Fusobacterium nucleatum were used as the polymicrobial oral inoculum in BALB/cByJ mice. The polymicrobial infection triggered significant alveolar bone loss, a heightened antibody response, an elevated cytokine immune response, a significant shift in viral diversity and virome composition, and a widening of the PDL space; the latter two findings have not been previously reported in periodontal disease models. Changes in the PDL space were present at sites far away from the site of insult, indicating that the polymicrobial radius of effect extends beyond the bone loss areas and site of initial infection and wider than previously appreciated. Associations were found between bone loss, specific viral and bacterial species, immune genes, and PDL space changes. These findings may have significant implications for the pathogenesis of periodontal disease and biomechanical properties of the periodontium. This new polymicrobial mouse model of periodontal disease in a common mouse strain is useful for evaluating the features of periodontal disease
Prevalence and Correlation of Human Papilloma Virus and its Types with Prognostic Markers in Patients with Invasive Ductal Carcinoma of the Breast in Kuwait
Objectives: This study aimed to document the association of human papilloma virus (HPV) and its types in breast carcinoma tissues in Kuwaiti women, and correlate this with known prognostic markers. Methods: The clinicopathological data of archived tissue from 144 cases of invasive ductal breast carcinoma were studied (age, histological grade, size of tumour, lymph node metastases, oestrogen/progesterone receptors and human epidermal growth factor receptor 2 status). HPV frequency was documented using immunohistochemistry (IHC) and chromogenic in-situ hybridisation (CISH). HPV types were documented by CISH using HPV probes. CISH and IHC techniques were compared and HPV correlated with prognostic parameters. Results: The HPV prevalence as determined by CISH and IHC was 51 (35.4%) and 24 (16.7%) cases, respectively. The sensitivity of HPV by IHC was 37.3% and specificity was 94.6%. The sensitivity and specificity of HPV-CISH compared to HPVIHC was statistically significant (P <0.001). HPV-CISH was seen in 51 cases. A combination of HPV 6 and 11, and 16 and 18 was seen in 2 (3.9%) cases, and a combination of HPV 6, 11, 31 and 33 was seen in 7 (13.7%) cases. All three HPV probes: 6 and 11, 16 and 18, as well as 31 and 33 were present in 2 (3.9%) cases. The prevalence of HPVCISH in the Kuwaiti and non-Kuwaiti populations was 27 (52.9%) and 19 (37.2%), respectively. No correlation was observed with the prognostic parameters. Conclusion: The frequency of HPV in breast carcinoma cases in Kuwait was 35.4% (CISH). Of those, 52.9% were Kuwaitis in whom both low- and high-risk HPV types were detected
A rather unconventional use of the laryngeal mask airway
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74753/1/j.1460-9592.2007.02283.x.pd
Treponema denticola increases MMP‐2 expression and activation in the periodontium via reversible DNA and histone modifications
Host‐derived matrix metalloproteinases (MMPs) and bacterial proteases mediate destruction of extracellular matrices and supporting alveolar bone in periodontitis. The Treponema denticola dentilisin protease induces MMP‐2 expression and activation in periodontal ligament (PDL) cells, and dentilisin‐mediated activation of pro‐MMP‐2 is required for cellular fibronectin degradation. Here, we report that T. denticola regulates MMP‐2 expression through epigenetic modifications in the periodontium. PDL cells were treated with epigenetic enzyme inhibitors before or after T. denticola challenge. Fibronectin fragmentation, MMP‐2 expression, and activation were assessed by immunoblot, zymography, and qRT‐PCR, respectively. Chromatin modification enzyme expression in T. denticola‐challenged PDL cells and periodontal tissues were evaluated using gene arrays. Several classes of epigenetic enzymes showed significant alterations in transcription in diseased tissue and T. denticola‐challenged PDL cells. T. denticola‐mediated MMP‐2 expression and activation were significantly reduced in PDL cells treated with inhibitors of aurora kinases and histone deacetylases. In contrast, DNA methyltransferase inhibitors had little effect, and inhibitors of histone acetyltransferases, methyltransferases, and demethylases exacerbated T. denticola‐mediated MMP‐2 expression and activation. Chronic epigenetic changes in periodontal tissues mediated by T. denticola or other oral microbes may contribute to the limited success of conventional treatment of chronic periodontitis and may be amenable to therapeutic reversal.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142926/1/cmi12815.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142926/2/cmi12815_am.pd
Direct injection-HPLC analysis for the determination of furanic compounds in oil as markers of solid insulation degradation in power transformers
Formation of random singlets in the nanocrystalline quasi-one-dimensional spin-1/2 antiferromagnet Sr21Bi8Cu2(CO3)2O41
Induced by quenched disorder, random-singlet states occur in a variety of
low-dimensional spin-1/2 antiferromagnets, some of them candidates for quantum
spin liquids. Here we report measurements of the specific heat, magnetization,
and magnetic susceptibility of nanocrystalline Sr21Bi8Cu2(CO3)2O41, a
quasi-one-dimensional spin-1/2 antiferromagnet with alternating bonds. The
results uncover the predominant presence of random-singlet spin pairs in this
material, with a logarithmic probability distribution, P(J), of the
renormalized, emergent exchange interaction, J, in zero magnetic field and P(J)
proportional to 1/J in magnetic fields. We postulate that these unexpected J
dependences, in contrast to the usual P(J) \propto 1/ with 0 <
< 1, and possibly also the dichotomy, arise from the finite size of
the nanocrystals. Scaling functions for the specific heat and magnetization
reproduce our magnetocaloric-effect data, with no adjustable parameters
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