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Acute myocardial infarction (AMI) during pregnancy or the early postpartum period is rare, but can be devastating for both the mother and the fetus. There have been major advances in the diagnosis and treatment of acute coronary syndromes in the general population, but there is little consensus on the approach to diagnosis and treatment of pregnant women. This article reviews the literature relating to the pathophysiology of AMI in pregnant patients and the challenges in diagnosis and treatment of ST-elevation myocardial infarction (STEMI) in this unique population. From a cardiologist, maternal-fetal medicine specialist, and anesthesiologist's perspective, we provide recommendations for the diagnosis and management of STEMI occurring during pregnancy.

The polycarbonate/poly(acrylonitrile butadiene styrene) blends, (PC/ABS), are mainly degraded by sunlight known as photodegradation when exposed to outdoor conditions. It is the ultraviolet (UV) radiation that is responsible for the degradation of the blend. To stabilize against the harmful UV radiation and to scavenge the radical species which arise from UV or thermally induced degradation of the PC or the ABS, UV absorbers, and UV stabilizers are used. In this article three different UV absorbers namely, Tinuvin 1577—hydroxyphenyl triazine type, Cyasorb 5411—benzotriazole type, Uvinul 3030—cyanoacrylate type, and two different UV stabilizers, Tinuvin 765—monomeric hindered amine type, Tinuvin 622—oligomeric hindered amine were compounded in different combinations with PC/ABS blend at 240°C using a twin screw extruder. Accelerated aging of the compounded sample was done by Atlas Suntest apparatus. The photodegradation studies were done using UV–vis, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, and Yellowing index measurement. The molecular weight of the compounded sample before aging was determined by gel permeation chromatography (GPC). It was found that samples protected with hydroxyphenyl triazine type UV absorber and oligomeric hindered amine show the best result for decreasing the degradation products, oxidation rate, and yellowing of the PC/ABS blend. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

When polycarbonate (PC)/poly(acrylonitrile–butadiene–styrene) (ABS) blends are exposed to outdoor conditions, they are mainly degraded by sunlight; this is known as photodegradation. It is the ultraviolet radiation in the sunlight that is responsible for the degradation of the blend. To stabilize the blend against the harmful ultraviolet radiation, ultraviolet absorbers (UVAs) are used. In this study, three different UVAs—Tinuvin 1577 (a hydroxyphenyl triazine type), Cyasorb 5411 (a benzotriazole type), and Uvinul 3030 (a cyanoacrylate type)—were compounded with a PC/ABS blend at 240°C with a twin-screw extruder. Accelerated aging of the compounded sample was done by an Atlas Suntest containing xenon lamp. The degradation studies were performed with ultraviolet–visible spectroscopy, attenuated total reflectance/Fourier transform infrared spectroscopy, and yellowing index measurements. The molecular weight of the compounded sample was determined by gel permeation chromatography. It was found that hydroxyphenyl triazine type UVA showed the best results for decreasing the degradation products, oxidation rate, and yellowing of the PC/ABS blend. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Programmed cell death is a necessary part of development and tissue homeostasis enabling the removal of unwanted cells. In the setting of infectious disease, cells that have been commandeered by microbial pathogens become detrimental to the host. When macrophages and dendritic cells are compromised in this way, they can be lysed by pyroptosis, a cell death mechanism that is distinct from apoptosis and oncosis/necrosis. Pyroptosis is triggered by Caspase-1 after its activation by various inflammasomes and results in lysis of the affected cell. Both pyroptosis and apoptosis are programmed cell death mechanisms but are dependent on different caspases, unlike oncosis. Similar to oncosis and unlike apoptosis, pyroptosis results in cellular lysis and release of the cytosolic contents to the extracellular space. This event is predicted to be inherently inflammatory and coincides with interleukin-1β (IL-1β) and IL-18 secretion. We discuss the role of distinct inflammasomes, including NLRC4, NLRP3, and AIM2, as well as the role of the ASC focus in Caspase-1 signaling. We further review the importance of pyroptosis in vivo as a potent mechanism to clear intracellular pathogens.

The immunostimulatory properties conferred by vaccine adjuvants require caspase-1 for processing of IL-1β and IL-18. Caspase-1 is activated in response to a breach of the cytosolic compartment by microbes and the process is initiated by intracellular pattern recognition receptors within inflammasomes. Listeria monocytogenes is detected in the cytosol by the NLRC4, NLRP3 and AIM2 inflammasomes. NLRC4 is activated by flagellin, and L. monocytogenes evades NLRC4 by repressing flagellin expression. We generated an L. monocytogenes strain that was forced to express flagellin in the host cell cytosol. This strain hyperactivated caspase-1 and was preferentially cleared via NLRC4 detection in an IL-1β/IL-18 independent manner. We also created a strain of L. monocytogenes with forced expression of another NLRC4 agonist, PrgJ, from the Type III secretion system of Salmonella typhimurium. Forced expression of flagellin or PrgJ resulted in attenuation, yet both strains conferred protective immunity in mice against lethal challenge with L. monocytogenes. This work is the first demonstration of specific targeting of the caspase-1 activation pathway to generate a safe and potent L. monocytogenes-based vaccine. Moreover, the attenuated strains with embedded flagellin or PrgJ adjuvants represent attractive vectors for vaccines aimed at eliciting T-cell responses.

Several RNA viruses can be detected by the inflammasome, which promotes IL-1β and IL-18 secretion, but the underlying mechanisms of detection remain unclear. Cytosolic dsRNA is a replication intermediate of many RNA viruses. We show here that transfection of the dsRNA analogue poly I:C activates the NLRP3 inflammasome via a pathway requiring endosomal acidification. This detection is independent of the other poly I:C sensors: TLR3 and MDA5. These results suggest a mechanism by which cytosolic dsRNA produced during viral infection could activate the NLRP3 inflammasome.

Without stabilization, polycarbonate (PC)/poly(acrylonitrile–butadiene–styrene) (ABS) blends are susceptible to a loss of mechanical properties after a few days of exposure to weathering conditions. ABS can be stabilized against terrestrial light by the use of hindered amines in combination with a UV absorber; such hindered amines cannot be used when PC is present in the polymer blend. The hydrolysis of PC is accelerated when a small amount of a hindered amine light stabilizer (HALS) is incorporated into the resin and is exposed to elevated temperatures. In this study, three different HALSs (Tinuvin 123, Tinuvin 770, and Tinuvin 765, Ciba, Basel, Switzerland) were used as UV stabilizers for PC/ABS blends, and their effects on the PC phase were observed with online ultraviolet–visible spectroscopy on extruded flat films. These stabilizers were compounded with the blends in a corotating twin-screw extruder at 240°C. The molecular weight of the compounded samples was determined by gel permeation chromatography. The extent of degradation induced by the HALSs on the PC phase was found to be a function of its chemical structure. Tinuvin 123 with an amino ether functional group enhanced degradation in comparison with Tinuvin 770 and Tinuvin 765. Tinuvin 770, a secondary amine, was apt to be more reactive than Tinuvin 765, a tertiary amine, because less steric hindrance was experienced by the former. Accelerated aging of the compounded samples was performed. Decreased degradation was observed for the samples containing hindered amines; however, the HALSs alone were not effective in protecting the PC/ABS blends against harmful UV light. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

The polycarbonate/polyacrylonitrile butadiene styrene (PC/ABS) blends lose mechanical properties when exposed to outdoor conditions. This is due to the ultraviolet (UV) induced photo-oxidation of the PC phase and the polybutadiene portion of the ABS. It is known that ABS can be stabilised against terrestrial light by the use of hindered amine in combination with a UV absorber. However, such hindered amine cannot be used when PC is present in a multi component polymer blend. The hydrolysis of PC is accelerated when a small amount of hindered amine light stabilisers (HALS) is incorporated in the resin and is exposed to elevated temperature. In this article the effect of monomeric and oligomeric hindered amine on the hydrolysis of PC during the compounding of PC/ABS blend in a twin screw extruder at 240°C is observed by means of in-line UV-vis spectroscopy. Tinuvin 765 was used as monomeric hindered amine and Tinuvin 622 as oligomeric hindered amine. The molecular weight of the compounded sample was determined by gel permeation chromatography (GPC) and the rheological properties were observed using an online viscometer. It was found that the extent of hydrolysis induced by the oligomeric hindered amine is less compared to monomeric amine. It was also observed that polymeric hindered amine imparts better dispersion of the ABS phase into the polymer blend. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Because of its high stiffness, chemical resistance, and low viscosity, Poly (oxymethylene) (POM) is of high relevance for technical applications. The thermal degradation of POM during processing affects its final properties and decreases the long-term stability. The degradation is indicated by the emission of formaldehyde (FA) gas. The aim of this study is to monitor the thermal degradation of POM online, during the melt extrusion in a co-rotating twin screw extruder (TSE). The effect of the processing conditions on the thermal stabilisation of the POM is observed by FA emission and online viscosity measurements. The effect of processing conditions on the compounding of POM with two different FA scavengers is also studied. Fourier transform infrared (FTIR) spectroscopy is used for the online measurement of FA gas and acetyl acetone colour measurement for the offline characterisation. The online viscosity is measured by passing the melt through a slit die at constant volume flow rate. An enhanced thermal degradation is found with decreasing throughput and increasing screw speed. A good correlation between the online viscosity and offline FA measurement is observed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

This paper shows that major components of modern manufacturing processes, such as inventory management and cross-training, play a significant control role. In our model, workers possess information that is critical to efficient ongoing operations. An organizational design that motivates workers to optimally apply this information leverages both the production schedule and worker–management communication. Management's use of these controls results in work-in-process (WIP) inventory that appears excessive from a pure job-scheduling perspective, but is optimal when control issues are considered. Empirical work testing pure job-scheduling theories of modern manufacturing practices has yielded mixed results. We provide control-related interpretations for these empirical findings, and also provide novel predictions regarding the link between inventory levels and the nature of operational information asymmetries. Overall, our model highlights the importance of recognizing both control and scheduling issues when analyzing production processes.

The reported cost of a product frequently contains historical cost com ponents that reflect past investments in productive capacity. We examine a setting wherein a firm makes a sequence of overlapping capacity investments. Earlier research has identified particular accrual accounting (depreciation) rules with the property that, on a per unit basis, the historical cost of a product captures precisely its marginal cost. Relative to this benchmark, we investigate and characterize the direction and magnitude of the bias in reported histori cal cost that results from alternative depreciation rules, including in particular straight-line depreciation in conjunction with partial direct expensing. In ad dition, we demonstrate that for a reasonable range of parameter specifications the resulting bias is rather small. Finally, we apply our framework to two spe cific settings. First, in a regulatory context, we establish the extent to which the accounting profit margin is indicative of a firm's pricing power in the product market. Second, we model an internal control scenario in which a manager's performance is evaluated using residual income, and identify the distortions in investment levels that result from the use of alternative depreciation rules.

There is growing interest in the use of markets within firms. Proponents have noted that markets are a simple and efficient mechanism for allocating resources in economies in which information is dispersed. In contrast to the use of markets in the broader economy, the efficiency of an internal market is determined in large part by the endogenous contractual incentives provided to the participating, privately informed agents. In this paper, we study the optimal design of managerial incentives when resources are allocated by an internal auction market, as well as the efficiency of the resulting resource allocations. We show that the internal auction market can achieve first-best resource allocations and decisions, but only at an excessive cost in compensation payments. We then identify conditions under which the internal auction market and associated optimal incentive contracts achieve the benchmark second-best outcome as determined using a direct revelation mechanism. The advantage of the auction is that it is easier to implement than the direct revelation mechanism. When the internal auction mechanism is unable to achieve second-best, we characterize the factors that determine the magnitude of the shortfall. Overall, our results speak to the robust performance of relatively simple market mechanisms and associated incentive systems in resolving resource allocation problems within firms.

Secretory phospholipase A2 (sPLA2-IIA) has been shown to attenuate intestinal tumorigenesis in Apc(Min) mice, demonstrating that it is a tumor modifier. To further explore the actions of sPLA2-IIA in tumorigenesis, sPLA2-IIA was overexpressed in two cell lines where it is normally absent, the murine colon tumor cell line AJ02nm0, and human colon carcinoma cell line HCT-116. Two allelic variants of sPLA2-IIA were tested in this study; sPLA2-IIA(AKR) and sPLA2-IIA(SWR), which are derived from AKR/J and SWR/J mice, respectively, and differ by a single amino acid at position 63 in the calcium- and receptor-binding domain. There was no change in cell-doubling time for either allele when compared to vector controls. Furthermore, sodium butyrate and arachidonic acid (AA)-induced cell death were unchanged in control and transfected cells. Addition of the sPLA2 substrate, palmitoyl-arachidonoyl-phosphatidic acid (PAPA), to AJ02nm0 cells resulted in a modest (12%-24%), but significant (P < 0.01), inhibition of growth that was dependent on sPLA2-IIA expression. However, when AJ02nm0 and HCT-116 cells were injected subcutaneously (sc) into nude mice, Pla2g2a expression resulted in a 2.5-fold increase in tumor size. In addition, sPLA2-IIA expressing HCT-116 tumors were found to be more infiltrative than controls. We conclude that the ability of sPLA2-IIA to slow tumor cell growth is dependent upon the availability of substrate, and that in some instances sPLA2-IIA may actually enhance tumor growth. Mechanisms that may account for differences between the tumor explant model versus the Apc(Min) model of intestinal cancer are discussed.

Key indicators of managerial performance are frequently subjective, that is, they are difficult to specify and/or verify for contracting purposes. When a principal must rely on subjective information to create incentives for a group of agents, discretionary bonus pools are shown to be optimal mechanisms. Despite their optimality, however, discretionary bonus pools entail an additional agency cost relative to the benchmark of optimal contracts based on objective and verifiable information. Our analysis identifies circumstances under which this additional agency cost is small, for example, the subjective information signals are precise, or the number of agents participating in the bonus pool increases. When incentive schemes can be based on both objective and subjective performance indicators, the relative weights to be placed on alternative signals are shown to differ from the ones predicted by models with objective signals only. We also demonstrate that correlation in measurement errors has a different impact on the structure of optimal incentive schemes when the performance indicators are merely subjective.

The hypothesis that the ingestion of garlic provides protection against bloodsucking pests such as mosquitoes was investigated using a randomized, double-blinded, placebo-controlled crossover study. Subjects were asked to consume either garlic (one visit) or a placebo (the other visit). They were then exposed to laboratory-reared Aedes aegypti (Linnaeus) (Diptera: Culicidae). The numbers of mosquitoes that did not feed on the subjects, the number of mosquito bites, the weights of the mosquitoes after feeding and the amounts of blood ingested were determined. The data did not provide evidence of significant systemic mosquito repellence. A limitation of the study is that more prolonged ingestion of garlic may be needed to accomplish repellence.

Integrally asymmetric hollow-fiber membranes each with an outer skin layer and a porous substrate were studied for air separation to produce nitrogen and oxygen enriched air. The test on both bore-side feed and shell-side feed with cocurrent and countercurrent flow arrangements for a wide range of stage cuts shows that the bore-side feed countercurrent flow was the most advantageous configuration in the permeator design. When operated in the bore-side feed countercurrent configuration, the permeator performance compared favorably with the commercial systems available for nitrogen production. A mathematical model was developed for this configuration. Since the concentration polarization in the substrate was a major concern for the bore-side feed configuration, especially for high stage-cut operations, a theoretical approach was pursued to formulate the concentration polarization. This allows for the diagnosis of the significance of concentration polarization in a specific permeation process, although it is difficult to predict concentration polarization accurately due to limited knowledge of the detailed membrane structure.

The diffusion of 2,2,4-trimethylpentane (TMP) and 2,2,5-trimethylhexane (TMH) vapors put of residually contaminated sandy soil from the U.S. Environmental Protection Agency (EPA) field research site at Traverse City, Michigan, was measured and modeled. The headspace of an intact core sleeve sample was swept with nitrogen gas to simulate the diffusive release of hydrocarbon vapors from residual aviation gasoline in and immediately above the capillary fringe to a soil-venting air flow in the unsaturated zone. The resulting steady-state profile was modeled using existing diffusivity and air porosity estimates in a balance of diffusive flux and a first order source term. The source strength, which was calibrated with the observed flux of 2,2,4-TMP leaving the sleeve, varied with the residual gasoline remaining in the core, but was independent of the headspace sweep flow rate. This finding suggested that lower soil-venting air flow rates were in principle as effective as higher air flow rates in venting LNAPL vapors from contaminated soils. The saturated vapor concentration ratio of 2,2,4-TMP to 2,2,5-TMH decreased from 6.6 to 3.5 over the duration of the experiments in an expression of distillation effects. The vertical profile model was tested against sample port data in four separate experiments for both species, yielding mean errors ranging from 0 to—24 percent in magnitude.

Mass spectra of methyl esters of three common drinking water chlorination by-products, bromodichloroacetic acid, dibromochloroacetic acid and tribromoacetic acid, are presented. The spectra are obtained in electron impact and chemical ionization modes, using a quadrupole mass spectrometer. Proposed fragment ion assignments are presented in detail. Fragment clusters were identified from their m/z values and confirmed with their relative isotope ratios. The detailed mass spectra presented are especially useful because standards for these drinking water contaminants are not yet commercially available.

Variants that no longer express an entire H-2 haplotype were readily isolated, by immunoselection with antisera directed against the haplotype, from an H-2b/H-2d heterozygous Friend leukemia cell line carrying a Robertsonian translocation of the chromosomes bearing the H-2 genetic region. These variants can be denoted as being of the phenotype H-2b- H-2d+ or H-2b+ H-2d-. Some of the H-2b- H-2d+ variants: (1) lack the restriction enzyme fragments characteristic of the missing H-2b haplotype, as assessed by Southern blot analysis; (2) express more cell surface H-2d antigens than wild-type cells, as assessed by flow microfluorimetry; and (3) appear to have become homozygous for the more active H-2d-linked allele at the Glyoxalase I locus. These variants thus seem to have lost genetic material corresponding to the H-2b haplotype and may have gained genetic material corresponding to the H-2d haplotype. These results are consistent with the possibility that these variants were generated by mitotic recombination.

An experimental study of transport phenomena at the wall of an agitated vessel with a propeller impeller under unsteady conditions is reported. The transient in heat transfer at the wall is caused by a step change in the speed of agitation from an initial static condition. The results are expressed in terms of a rise in modified “j-factor” above the initial free convection value and the number of revolutions taken by the impeller from the start of agitation. Also, an attempt has been made to find an analogy beween heat and momentum transfer. Results are given for the power in terms of Euler number plotted against the impeller Reynolds number. An empirical expression is also given for the transient heat transfer considering the system as a pure first order one with time delay. A “time-factor” constant which gives the number of impeller revolutions for 63.2% of the change from the initial to a final steady state is expressed as a function of impeller Reynolds number (102 to 106) and fluid Prandtl number (6 to 106). On expose une etude experimentale des phenomenes de transport sur la paroi d'un recipient agite avec un impulser a helice en regime transitoire. C'est un changement par stades de la vitesse d'agitation a partir de la condition statique initiale qui est responsable du transfert transitoire de la chaleur sur la paroi. On exprime les resultats en fonction du “facteur j” modifie au-dessus de la valeur initiale de convection libre et du nombre de tours de l'impulseur a helice a partir du debut de l'agitation. On a aussi cherche a trouver une analogie entre le transfert de la chaleur et celui de la force vive. On indique les resultats relatifs a l'energie sous forme de graphique ou l'abscisse est le nombre d'euler et l'ordonnee le nombre de Reynolds de l'impulseur. On fournit une expression empirique pour le transfert transitoire de chaleur, en considerant le systeme comme un de premier ordre avec retard. On definit, en fonction des nombres de Reynolds de l'impulseur a helice (102 a 106) et des nombres de Prandtl du fluide (6 a 106), une constante basee sur le temps, laquelle indique le nombre de tours de l'impulseur pour 63.2% du changement entre le regime initial et le regime final qui est permanent.