Next-generation solar power conversion systems in concentrating solar power (CSP) applications require high-temperature advanced fluids in the range of 600–800°C. Current commercial CSP plants use ...molten nitrate salt mixtures as the heat transfer fluid and the thermal energy storage (TES) media while operating with multiple hours of energy capacity and at temperatures lower than 565°C. At higher temperatures, the nitrates cannot be used because they decompose. Molten chloride salts are candidates for CSP applications because of their high decomposition temperatures and good thermal properties; but they can be corrosive to common alloys used in vessels, heat exchangers, and piping at these elevated temperatures. In this article, we present the results of the corrosion evaluations of several alloys in eutectic 34.42wt% NaCl – 65.58wt% LiCl at 650–700°C in nitrogen atmosphere. Electrochemical evaluations were performed using open-circuit potential followed by a potentiodynamic polarization sweep. Corrosion rates were determined using Tafel slopes and Faraday's law. A temperature increase of as little as 50°C more than doubled the corrosion rate of AISI stainless steel 310 and Incoloy 800H compared to the initial 650°C test. These alloys exhibited localized corrosion. Inconel 625 was the most corrosion-resistant alloy with a corrosion rate of 2.80±0.38mm/year. For TES applications, corrosion rates with magnitudes of a few millimeters per year are not acceptable because of economic considerations. Additionally, localized corrosion (intergranular or pitting) can be catastrophic. Thus, corrosion-mitigation approaches are required for advanced CSP plants to be commercially viable.
•The 50°C temperature increase, from the initial 650°C test, more than doubled the corrosion rate of SS310 and In800H.•IN625 was the most corrosion-resistant alloy with a corrosion rate of 2.80±0.38 mm/year at 650°C.•SS347, with the lowest Ni content of 9.62 wt%, has the highest corrosion rate of 7.49±0.32 mm/year at 650°C.•Cr and Fe were preferentially corroded from SS310, In800H, and IN625.
Patients with lysosomal storage diseases may require modifications to standard drug desensitization protocols; personalized medicine as well as development of new treatment options are needed.
Abstract
STUDY QUESTION
Is there a relationship between serum and endometrial progesterone (P4) levels, including P4 and metabolites (oestrone, oestradiol and 17α-hydroxyprogesterone), and ...endometrial receptivity?
SUMMARY ANSWER
Serum P4 levels were not correlated with endometrial P4, nor associated with endometrial receptivity as determined by the ERA® test; however, endometrial P4 and 17α-hydroxyprogesterone levels were positively correlated and related to endometrial receptivity by ERA.
WHAT IS KNOWN ALREADY
Acquisition of endometrial receptivity is governed by P4, which induces secretory transformation. A close relationship between serum P4 and pregnancy outcome is reported for hormone replacement therapy (HRT) cycles. However, the relationship between serum and uterine P4 levels has not been described, and it is unknown whether uterine receptivity depends more on serum or uterine P4 levels.
STUDY DESIGN, SIZE, DURATION
A prospective cohort study was performed during March 2018–2019 in 85 IVF patients undergoing an evaluation-only HRT cycle with oestradiol valerate (6 mg/day) and micronised vaginal progesterone (400 mg/12 h).
PARTICIPANTS/MATERIALS, SETTING, METHODS
Patients were under 50 years of age, had undergone at least one failed IVF cycle, had no uterine pathology, and had adequate endometrial thickness (> 6.5 mm). The study was conducted at IVI Valencia and IVI Foundation. An endometrial biopsy and a blood sample were collected after 5 days of P4 vaginal treatment. Measures included serum P4 levels, ERA®-based evaluation of endometrial receptivity, and endometrial P4 levels along with metabolites (oestrone, oestradiol and 17α-hydroxyprogesterone) measured by ultra-performance liquid chromatography–tandem mass spectrometry.
MAIN RESULTS AND THE ROLE OF CHANCE
Seventy-nine women were included (mean age: 39.9 ± 4.6, BMI: 24.2 ± 3.9 kg/m2, endometrial thickness: 8.2 ± 1.4 mm). The percentage of endometria indicated as receptive by ERA® was 40.5%. When comparing receptive versus non-receptive groups, no differences were observed in baseline characteristics nor in steroid hormones levels in serum or endometrium. No association between serum P4 and endometrial steroid levels or ERA result was found (P < 0.05). When the population was stratified according to metabolite concentration levels, endometrial P4 and 17α-hydroxyprogesterone were significantly associated with endometrial receptivity (P < 0.05). A higher proportion of receptive endometria by ERA was observed when endometrial P4 levels were higher than 40.07 µg/ml (relative maximum) and a lower proportion of receptive endometria was associated with endometrial 17α-hydroxyprogesterone lower than 0.35 ng/ml (first quartile). A positive correlation R2 = 0.67, P < 0.001 was observed between endometrial P4 and 17α-hydroxyprogesterone levels.
LIMITATIONS, REASONS FOR CAUTION
This study did not analyse pregnancy outcomes. Further, the findings can only be extrapolated to HRT cycles with micronised vaginal progesterone for luteal phase support.
WIDER IMPLICATIONS OF THE FINDINGS
Our findings suggest that the combined benefits of different routes of progesterone administration for luteal phase support could be leveraged to ensure an adequate concentration of progesterone both in the uterus and in the bloodstream. Further studies will confirm whether this method can optimise both endometrial receptivity and live birth rate. Additionally, targeted treatment to increase P4 endometrial levels may normalise the timing of the window of implantation without needing to modify the progesterone administration day.
STUDY FUNDING/COMPETING INTEREST(S)
This research was supported by the IVI-RMA Valencia (1706-VLC-051-EL) and Consellería d’Educació, Investigació, Cultura, i esport Generalitat Valenciana (Valencian Government, Spain, GV/2018//151). Almudena Devesa-Peiro (FPU/15/01398) and Cristina Rodriguez-Varela (FPU18/01657) were supported by the FPU program fellowship from the Ministry of Science, Innovation and Universities (Spanish Government). P.D.-G. is co-inventor on the ERA patent, with non-economic benefits. The other authors have no competing interests.
TRIAL REGISTRATION NUMBER
NCT03456375.
The aim of this research is to compare the electrochemical behaviour of two biomedical alloys, AISI 316L and CoCrMo in simulated body fluids. This comparison is focused on the influence of solution ...chemistry and immersion time on the passive behaviour using electrochemical techniques, potentiodynamic curves, potentiostatic tests and electrochemical impedance spectroscopy (EIS).
Influence of albumin, used as model protein, on both biomaterials depends on the nature of the alloy. It decreases the corrosion resistance of AISI 316L while increases the corrosion resistance of CoCrMo. Although it is known that it adsorbs on both alloys, properties of the passive layer modifies the effect of albumin. On the contrary, precipitation of phosphate ions could explain the highest resistance values in the phosphate solutions on both cases.
The study shows that the electrochemical behaviour of CoCrMo shows higher transfer resistance and lower capacitance which means thicker and more protective passive films than AISI 316L. However, differences between both alloys disappear with time depending on the solution chemistry.
Degradation of dentin matrix components within caries dentin has been correlated with the activity of host-derived proteases, such as matrix metalloproteases (MMPs) and cysteine cathepsins (CTs). ...Since this relationship has not been fully established, we hypothesized that the abundance of MMPs and CTs in caries-affected dentin must be higher than in intact dentin. To test this premise, we obtained 5 slices (200 µm) from 5 intact teeth and from 5 caries-affected teeth (1 slice/tooth) and individually incubated them with primary antibodies for CT-B, CT-K, MMP-2, or MMP-9. Negative controls were incubated with pre-immune serum. Specimens were washed and re-incubated with the respective fluorescent secondary antibody. Collagen identification, attained by the autofluorescence capture technique, and protease localization were evaluated by multi-photon confocal microscopy. The images were analyzed with ZEN software, which also quantitatively measured the percentages of collagen and protease distribution in dentin compartments. The abundance of the test enzymes was markedly higher in caries-affected than in intact dentin. CT-B exhibited the highest percentage of co-localization with collagen, followed by MMP-9, MMP-2, and CT-K. The high expression of CTs and MMPs in caries-affected teeth indicates that those host-derived enzymes are intensely involved with caries progression.
Oligomeric proanthocyanidins (OPACs) are potent and renewable natural bioactives possible to be refined into chemically standardized mixtures for biological applications. Herein, we found that ...multiscale interactions of OPACs with the dentin matrix create tight biointerfaces with hydrophobic methacrylate adhesives on wet surfaces. An enriched mixture of OPACs, with a known phytochemical profile, was produced from grape seed crude extract (Vitis vinifera; enriched grape seed extract e-GSE) and applied to dentin matrices to determine changes to the mechanical properties and biodegradability of the dentin matrix and favorable resin adhesion mechanisms. Methods included a 3-point flexural test, quantification of hydroxyproline (collagen solubilization), static and dynamic nanomechanical analyses, resin-dentin microtensile bond strength, and micropermeability at the adhesive interface. The e-GSE-modified dentin matrix exhibited remarkably low collagen solubilization and sustained the bulk elastic properties over 12 mo. Tan δ findings reveal a more elastic-like behavior of the e-GSE-modified dentin matrix, which was not affected by H-bond destabilization by urea. Dentin-methacrylate biointerfaces with robust and stable adhesion were created on e-GSE-primed dentin surfaces, leading to a dramatic decrease of the interfacial permeability. Standardized OPAC mixtures provide a new mechanism of adhesion to type I collagen–rich tissues that does not rely on hydrophilic monomers. The bioadhesion mechanism involves physicochemical modifications to the dentin matrix, reduced tissue biodegradation, and bridging to methacrylate resins.
Feedstock particle sizing can impact the economics of cellulosic ethanol commercialization through its effects on conversion yield and energy cost. Past studies demonstrated that particle size ...influences biomass enzyme digestibility to a limited extent. Physical size reduction was able to increase conversion rates to maximum of ≈50%, whereas chemical modification achieved conversions of >70% regardless of biomass particle size. This suggests that (1) mechanical pretreatment by itself is insufficient to attain economically feasible biomass conversion, and, therefore, (2) necessary particle sizing needs to be determined in the context of thermochemical pretreatment employed for lignocellulose conversion. Studies of thermochemical pretreatments that have taken into account particle size as a factor have exhibited a wide range of maximal sizes (i.e., particle sizes below which no increase in pretreatment effectiveness, measured in terms of the enzymatic conversion resulting from the pretreatment, were observed) from <0.15 to 50 mm. Maximal sizes as defined above were dependent on the pretreatment employed, with maximal size range decreasing as follows: steam explosion > liquid hot water > dilute acid and base pretreatments. Maximal sizes also appeared dependent on feedstock, with herbaceous or grassy biomass exhibiting lower maximal size range (<3 mm) than woody biomass (>3 mm). Such trends, considered alongside the intensive energy requirement of size reduction processes, warrant a more systematic study of particle size effects across different pretreatment technologies and feedstock, as a requisite for optimizing the feedstock supply system.
Transcription factors and their associated DNA binding sites are key regulatory elements of cellular differentiation, development, and environmental response. New tools that predict transcriptional ...regulation of biological processes are valuable to researchers studying both model and emerging-model plant systems. SeqEnrich predicts transcription factor networks from co-expressed Arabidopsis or Brassica napus gene sets. The networks produced by SeqEnrich are supported by existing literature and predicted transcription factor-DNA interactions that can be functionally validated at the laboratory bench. The program functions with gene sets of varying sizes and derived from diverse tissues and environmental treatments. SeqEnrich presents as a powerful predictive framework for the analysis of Arabidopsis and Brassica napus co-expression data, and is designed so that researchers at all levels can easily access and interpret predicted transcriptional circuits. The program outperformed its ancestral program ChipEnrich, and produced detailed transcription factor networks from Arabidopsis and Brassica napus gene expression data. The SeqEnrich program is ideal for generating new hypotheses and distilling biological information from large-scale expression data.
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