•High circulating estradiol at induced ovulation improved embryo survival in beef cows.•Preovulatory estradiol had greater impact than luteal progesterone on embryo survival.•Postovulatory ...progesterone only improved pregnancy when preovulatory estradiol is low.•Preovulatory estradiol had a significant effect on pregnancy success in beef cows.
Two experiments were conducted to examine the effect of plasma concentrations of 17β-estradiol (E2) preceding and progesterone (P4) subsequent to ovulation on proportions of beef cows pregnant following embryo transfer. Timing of ovulation (d 0) among postpartum cows was synchronized and cows that expressed estrus were removed from each study. In Experiment 1, plasma E2 concentration on d 0 was used to classify cows (n = 353) into Low, Medium, and High E2 groups. Pregnancy rate for cows with Low, Medium, or High E2 concentrations were different (P < 0.05). In Experiment 2, there were multiple administrations of PGF2α to evaluate the independent effects of Low or High E2 before ovulation and Low or Normal (no treatment) P4 after ovulation on proportions of cows pregnant. Treatment groups in Experiment 2, therefore, were: Low E2-Low P4 (LL; n = 71), Low E2-Normal P4 (LN; n = 69), High E2-Low P4 (HL; n = 74), and High E2-Normal P4 (HN; n = 73). Concentrations of P4 on d 7 subsequent to ovulation were less (P < 0.05) in cows of the HL compared to HN, and in LL compared to LN groups. Concentrations of E2 on d -2, 0, and change in E2 (d -2 to d 0) had a positive effect (P < 0.008) on pregnancy rates. In summary, relatively greater E2 concentrations preceding ovulation; and relatively greater P4 concentrations subsequent to ovulation combined with lesser E2 concentrations preceding ovulation had a positive effect on proportions of postpartum cows pregnant.
Abstract
Background
The COVID-19 pandemic and global efforts to contain its spread, such as stay-at-home orders and transportation shutdowns, have created new barriers to accessing healthcare, ...resulting in changes in service delivery and utilization globally. The purpose of this study is to provide an overview of the literature published thus far on the indirect health effects of COVID-19 and to explore the data sources and methodologies being used to assess indirect health effects.
Methods
A scoping review of peer-reviewed literature using three search engines was performed.
Results
One hundred and seventy studies were included in the final analysis. Nearly half (46.5%) of included studies focused on cardiovascular health outcomes. The main methodologies used were observational analytic and surveys. Data were drawn from individual health facilities, multicentre networks, regional registries, and national health information systems. Most studies were conducted in high-income countries with only 35.4% of studies representing low- and middle-income countries (LMICs).
Conclusion
Healthcare utilization for non-COVID-19 conditions has decreased almost universally, across both high- and lower-income countries. The pandemic’s impact on non-COVID-19 health outcomes, particularly for chronic diseases, may take years to fully manifest and should be a topic of ongoing study. Future research should be tied to system improvement and the promotion of health equity, with researchers identifying potentially actionable findings for national, regional and local health leadership. Public health professionals must also seek to address the disparity in published data from LMICs as compared with high-income countries.
The accurate estimation of vitamin A deficiency (VAD) is critical to informing programmatic and policy decisions that could have important public health implications. However, serum retinol and ...retinol binding protein (RBP) concentrations, two biomarkers often used to estimate VAD, are temporarily altered during the acute phase response, potentially overestimating the prevalence of VAD in populations with high levels of inflammation. In 22 nationally-representative surveys, we examined (1) the association between C-reactive protein (CRP) or α1-acid glycoprotein (AGP) and retinol or RBP, and (2) how different adjustment approaches for correcting for inflammation compare with one another. In preschool age children (PSC) and school age children (SAC), the association between inflammation and retinol and RBP was largely statistically significant; using the regression approach, adjustments for inflammation decreased the estimated prevalence of VAD compared to unadjusted VAD (range: -22.1 to -6.0 percentage points). In non-pregnant women of reproductive age (WRA), the association between inflammation and vitamin A biomarkers was inconsistent, precluding adjustments for inflammation. The burden of VAD can be overestimated if inflammation is not accounted for, and the regression approach provides a method for adjusting retinol and RBP for inflammation across the full range of concentrations in PSC and SAC.
The concentration of ionized calcium required for the capping of barbed filament ends by villin is about 4 orders of magnitude lower than that required for the cutting activity of villin. Capping was ...50% complete at about 10-30 nM Ca2+, a level expected in resting cells, whereas the cutting rate was half-maximal at about 200 microM, making it possible to completely separate filament capping from filament cutting. Analysis of capping in terms of coupled equilibria between calcium binding to villin and calcium-villin binding to the barbed ends of actin filaments gives a value of 10(16)-10(17) M-2 for the product of the two binding constants. By comparison the binding constant reported for the rapidly exchanging calcium sites on villin is 2 X 10(5) M-1 and that for binding of calcium-saturated villin to barbed ends has a minimum value of 10(11) M-1 giving a product of 2 X 10(16) M-1. The close similarity of the two sets of values suggests that capping is regulated by the rapidly exchanging calcium sites on villin. In terms of coupled equilibria the calcium requirement for filament capping decreases with increasing concentrations of free villin. The scant information on the mechanism of cutting allows only an estimate of the maximal value for the calcium-binding constant of the site regulating cutting which is about 2-5 X 10(3) M-1. Cutting is followed by rapid capping of the newly released barbed ends.
The Source Book serves as an introduction to present-day chemistry and can also be used as supplementary reading in general chemistry courses, since, in many instances, the papers explain the ...circumstances under which a particular discovery was made--information that is customarily lacking in textbooks. Although the selections are classified into the usual branches of the science, it will be apparent to the reader how the discoveries in any one branch were taken up and incorporated into others.
Linear Artificial Molecular Muscles Liu, Yi; Flood, Amar H; Bonvallet, Paul A ...
Journal of the American Chemical Society,
07/2005, Letnik:
127, Številka:
27
Journal Article
Recenzirano
Odprti dostop
Two switchable, palindromically constituted bistable 3rotaxanes have been designed and synthesized with a pair of mechanically mobile rings encircling a single dumbbell. These designs are reminiscent ...of a “molecular muscle” for the purposes of amplifying and harnessing molecular mechanical motions. The location of the two cyclobis(paraquat-p-phenylene) (CBPQT4+) rings can be controlled to be on either tetrathiafulvalene (TTF) or naphthalene (NP) stations, either chemically (1H NMR spectroscopy) or electrochemically (cyclic voltammetry), such that switching of inter-ring distances from 4.2 to 1.4 nm mimics the contraction and extension of skeletal muscle, albeit on a shorter length scale. Fast scan-rate cyclic voltammetry at low temperatures reveals stepwise oxidations and movements of one-half of the 3rotaxane and then of the other, a process that appears to be concerted at room temperature. The active form of the bistable 3rotaxane bears disulfide tethers attached covalently to both of the CBPQT4+ ring components for the purpose of its self-assembly onto a gold surface. An array of flexible microcantilever beams, each coated on one side with a monolayer of 6 billion of the active bistable 3rotaxane molecules, undergoes controllable and reversible bending up and down when it is exposed to the synchronous addition of aqueous chemical oxidants and reductants. The beam bending is correlated with flexing of the surface-bound molecular muscles, whereas a monolayer of the dumbbell alone is inactive under the same conditions. This observation supports the hypothesis that the cumulative nanoscale movements within surface-bound “molecular muscles” can be harnessed to perform larger-scale mechanical work.
•We use a chemical refinery model and exergy analysis to determine the impact of hydrous ethanol.•The process is 70% efficient with 86% of the losses from fermentation, steam generation and ...drying.•We found that producing 86wt% ethanol is optimal for thermal energy consumption.•Hydrous ethanol production can reduce energy costs and emissions by ∼8%.•Hydrous ethanol reduces water use by decreasing evaporation in cooling towers.
Sub-azeotropic hydrous ethanol has been demonstrated as an effective diesel fuel replacement when used in dual-fuel compression ignition engines. Previous studies have also suggested that hydrous ethanol may be more efficient to produce from corn than anhydrous ethanol. In this study, we investigate corn ethanol production from a dry-mill, natural gas-fired corn ethanol refinery, producing ethanol with a range of ethanol concentrations from 58wt% to 100wt% to determine the effect on energy use, water consumption and greenhouse gas (GHG) emissions in the refining stage of the corn ethanol lifecycle. A second law (exergy) analysis of anhydrous ethanol refining revealed the overall process to be 70% efficient, whereby 86% of the exergy losses could be accounted for by three processes: fermentation (34%), steam generation (29%) and distiller’s grains and solubles drying (23%).
We found that producing 86wt% ethanol is optimal as thermal energy consumption decreases by a maximum of 10% (from 7.7MJ/L to 6.9MJ/L). These savings have the potential to reduce energy costs by approximately 8% ($0.34/L) and reduce refinery emissions by 8% (2gCO2e/MJ). Production of hydrous ethanol reduced refinery water use due to decreased evaporative losses in the cooling towers, leading to water savings of between 3% and 6% at 86wt% ethanol.
Dicarboxylic acids play an important role in atmospheric chemistry, yet their emissions from primary sources, such as internal combustion engines, has not been extensively studied. In this work, KOH ...impregnated quartz filters were loaded with exhaust gases from a gasoline direct injection (GDI) engine equipped with a catalytic gasoline particulate filter (GPF). All filters were analyzed for carboxylic and dicarboxylic acids using a derivatized gas chromatography-mass spectroscopy method. Exhaust gas was sampled from pre-GPF and post-GPF locations to determine the performance of the GPF regarding acid conversion. Lean and stoichiometric engine modes were considered with non-oxygenated gasoline and 10% splash blended ethanol in gasoline (E10) to examine the impact of stoichiometry and fuel type. Acid emissions represented as much as 0.51% of total unburned hydrocarbon emissions for total monocarboxylic acids and as much as 0.40% for total dicarboxylic acids. Individual acid concentrations were as high as 38 mg/kg-fuel for monocarboxylic acids and as high as 29 mg/kg-fuel for dicarboxylic acids. Overall, the study found that fuel oxygenates had mixed impact on the acid emissions. Engine-out monocarboxylic acids were reduced when using the E10 fuel by approximately 30–45% for the stoichiometric condition and increased marginally for the lean condition. Dicarboxylic acid emissions were generally insensitive to ethanol content. However, the engine condition significantly affected the acid emissions. Lean operation produced a factor of two to an order of magnitude higher emissions rates of both monocarboxylic and dicarboxylic acids than the stoichiometric condition. The catalytic GPF eliminated between 80 and 92% of the acids emitted from the engine, allowing some acids to be emitted into the environment.
OBJECTIVES:Physical and psychologic deficits after an ICU admission are associated with lower quality of life, higher mortality, and resource utilization. This study aimed to examine the prevalence ...and secular changes of functional status deterioration during hospitalization among nonsurgical critical illness survivors over the past decade.
DESIGN:We performed a retrospective longitudinal cohort analysis.
SETTING:Analysis performed using the Cerner Acute Physiology and Chronic Health Evaluation outcomes database which included manually abstracted data from 236 U.S. hospitals from 2008 to 2016.
PATIENTS:We included nonsurgical adult ICU patients who survived their hospitalization and had a functional status documented at ICU admission and hospital discharge. Physical functional status was categorized as fully independent, partially dependent, or fully dependent.
INTERVENTIONS:None.
MEASUREMENTS AND MAIN RESULTS:Functional status deterioration occurred in 38,116 patients (29.3%). During the past decade, functional status deterioration increased in each disease category, as well as overall (prevalence rate ratio, 1.15; 95% CI, 1.13–1.17; p < 0.001). Magnitude of functional status deterioration also increased over time (odds ratio, 1.03; 95% CI, 1.03–1.03; p < 0.001) with hematological, sepsis, neurologic, and pulmonary disease categories having the highest odds of severe functional status deterioration.
CONCLUSIONS:Following nonsurgical critical illness, the prevalence of functional status deterioration and magnitude increased in a nationally representative cohort, despite efforts to reduce ICU dysfunction over the past decade. Identifying the prevalence of functional status deterioration and primary etiologies associated with functional status deterioration will elucidate vital areas for further research and targeted interventions. Reducing ICU debilitation for key disease processes may improve ICU survivor mortality, enhance quality of life, and decrease healthcare utilization.
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