ABSTRACT
Combating global warming-related climate change demands prompt actions to reduce greenhouse gas emissions, particularly carbon dioxide. Biomass-based biofuels represent a promising alternative fossil energy source. To convert biomass into energy, numerous conversion processes are performed at high pressure and temperature conditions, and the design and dimensioning of such processes requires thermophysical property data, particularly thermal conductivity, which are not always available in the literature. In this paper, we proposed the application of Chemoinformatics methodologies to investigate the prediction of thermal conductivity for hydrocarbons and oxygenated compounds. A compilation of experimental data followed by a careful data curation were performed to establish a database. The support vector machine algorithm has been applied to the database leading to models with good predictive abilities. The support vector regression (SVR) model has then been applied to an external set of compounds, i.e. not considered during the training of models. It showed that our SVR model can be used for the prediction of thermal conductivity values for temperatures and/or compounds that are not covered experimentally in the literature.
Subject(s)
Global Warming , Quantitative Structure-Activity Relationship , Temperature , Thermal Conductivity , Machine LearningABSTRACT
A retrospective cohort study was performed to examine whether, in artificial endometrial preparation for frozen embryo transfer (FET) cycles, progesterone (P) levels the day prior to embryo transfer of euploid embryos have an impact on pregnancy outcomes. In a private university clinic, 244 FETs between January 2016 and June 2017 were analyzed. Endometrial preparation was achieved with estradiol valerate and vaginal micronized progesterone. Serum P and estradiol levels the day prior to embryo transfer were measured. A multivariable analysis to assess the relationship between serum P level and pregnancy outcomes was performed, adjusted for confounding variables. Mean P value was 11.3 ± 5.1 ng/ml. Progesterone levels were split in quartiles: Q1: ≤ 8.06 ng/ml; Q2: 8.07-10.64 ng/ml; Q3: 10.65-13.13 ng/ml; Q4: > 13.13 ng/ml. Patients included in the lower P quartile had a significantly higher miscarriage rate and significantly lower live birth rate (LBR) compared to the higher ones. A low serum P level (≤ 10.64 ng/ml) one day before FET is associated with a lower pregnancy and LBR following FET of euploid embryos.
Subject(s)
Embryo Transfer/methods , Fertilization in Vitro , Pregnancy Outcome , Progesterone/blood , Adult , Birth Rate , Cryopreservation , Female , Humans , Live Birth , Pregnancy , Retrospective Studies , Risk FactorsABSTRACT
In the modern theory of critical phenomena, the liquid-vapor density diameter in simple fluids is generally expected to deviate from a rectilinear law approaching the critical point. However, by performing precise scannerlike optical measurements of the position of the SF_{6} liquid-vapor meniscus, in an approach much closer to criticality in temperature and density than earlier measurements, no deviation from a rectilinear diameter can be detected. The observed meniscus position from far (10K) to extremely close (1mK) to the critical temperature is analyzed using recent theoretical models to predict the complete scaling consequences of a fluid asymmetry. The temperature dependence of the meniscus position appears consistent with the law of rectilinear diameter. The apparent absence of the critical hook in SF_{6} therefore seemingly rules out the need for the pressure scaling field contribution in the complete scaling theoretical framework in this SF_{6} analysis. More generally, this work suggests a way to clarify the experimental ambiguities in the simple fluids for the near-critical singularities in the density diameter.
ABSTRACT
In order to investigate at the pore scale the mechanisms involved during CO2 injection in a water saturated pore network, a series of displacement experiments is reported using high pressure micromodels (geological labs on chip - GLoCs) working under real geological conditions (25 < T (°C) < 75 and 4.5 < p (MPa) < 8). The experiments were focused on the influence of three experimental parameters: (i) the p, T conditions, (ii) the injection flow rates and (iii) the pore network characteristics. By using on-chip optical characterization and imaging approaches, the CO2 saturation curves as a function of either time or the number of pore volume injected were determined. Three main mechanisms were observed during CO2 injection, namely, invasion, percolation and drying, which are discussed in this paper. Interestingly, besides conventional mechanisms, two counterintuitive situations were observed during the invasion and drying processes.
ABSTRACT
In this work, the solvent effect on the synthesis of CeO2 nanocrystals synthesized in near- and supercritical alcohols is discussed. The materials prepared displayed a unique morphology of small nanocrystals (<10 nm) aggregated into larger nanospheres (â¼100-200 nm). In such syntheses, alcohol molecules directly interact with the nanocrystal surface through alkoxide and carboxylate bondings. The grafting density was quantified from the weight loss measured using thermogravimetric analysis. A direct correlation between the grafting density and the alcohol chain length can be established. It was demonstrated that the shorter the alcohol chain length (i.e. methanol), the higher the surface coverage is. This trend is independent of the synthesis mode (batch or continuous). Additionally, an influence of the grafting density on the resulting nanocrystal size was established. It is suggested that the surface coverage has a high influence on the early stages of the nucleation and growth. Indeed, when high surface coverages are reached, all surface active sites are blocked, limiting the growth step and therefore leading to smaller particles. This effect was noticed with the materials prepared in the continuous mode where shorter reaction time was performed.
ABSTRACT
Near the critical point of fluids, critical opalescence results in light attenuation, or turbidity increase, that can be used to probe the universality of critical behavior. Turbidity measurements in SF6 under weightlessness conditions on board the International Space Station are performed to appraise such behavior in terms of both temperature and density distances from the critical point. Data are obtained in a temperature range, far (1 K) from and extremely close (a few µK) to the phase transition, unattainable from previous experiments on Earth. Data are analyzed with renormalization-group matching classical-to-critical crossover models of the universal equation of state. It results that the data in the unexplored region, which is a minute deviant from the critical density value, still show adverse effects for testing the true asymptotic nature of the critical point phenomena.
ABSTRACT
The potential of dietary supplements of 2 live yeast strains (Saccharomyces cerevisiae) or camelina oil to lower ruminal methane (CH4) and carbon dioxide (CO2) production and the associated effects on animal performance, rumen fermentation, rumen microbial populations, nutrient metabolism, and milk fatty acid (FA) composition of cows fed grass silage-based diets were examined. Four Finnish Ayrshire cows (53±7 d in milk) fitted with rumen cannula were used in a 4×4 Latin square with four 42-d periods. Cows received a basal total mixed ration (control treatment) with a 50:50 forage-to-concentrate ratio [on a dry matter (DM) basis] containing grass silage, the same basal total mixed ration supplemented with 1 of 2 live yeasts, A or B, administered directly in the rumen at 10(10) cfu/d (treatments A and B), or supplements of 60g of camelina oil/kg of diet DM that replaced concentrate ingredients in the basal total mixed ration (treatment CO). Relative to the control, treatments A and B had no effects on DM intake, rumen fermentation, ruminal gas production, or apparent total-tract nutrient digestibility. In contrast, treatment CO lowered DM intake and ruminal CH4 and CO2 production, responses associated with numerical nonsignificant decreases in total-tract organic matter digestibility, but no alterations in rumen fermentation characteristics or changes in the total numbers of rumen bacteria, methanogens, protozoa, and fungi. Compared with the control, treatment CO decreased the yields of milk, milk fat, lactose, and protein. Relative to treatment B, treatment CO improved nitrogen utilization due to a lower crude protein intake. Treatment A had no influence on milk FA composition, whereas treatment B increased cis-9 10:1 and decreased 11-cyclohexyl 11:0 and 24:0 concentrations. Treatment CO decreased milk fat 8:0 to 16:0 and total saturated FA, and increased 18:0, 18:1, 18:2, conjugated linoleic acid, 18:3n-3, and trans FA concentrations. Decreases in ruminal CH4 production to treatment CO were related, at least in part to lowered DM intake, whereas treatments had no effect on ruminal CH4 emission intensity (g/kg of digestible organic matter intake or milk yield). Results indicated that live yeasts A and B had no influence on animal performance, ruminal gas production, rumen fermentation, or nutrient utilization in cows fed grass silage-based diets. Dietary supplements of camelina oil decreased ruminal CH4 and CO2 production, but also lowered the yields of milk and milk constituents due to an adverse effect on intake.
Subject(s)
Brassicaceae/chemistry , Cattle/metabolism , Methane/biosynthesis , Plant Oils/administration & dosage , Rumen/metabolism , Saccharomyces cerevisiae/physiology , Animals , Carbon Dioxide/metabolism , Diet/veterinary , Dietary Supplements , Digestion/drug effects , Fatty Acids/analysis , Female , Fermentation , Lactation/drug effects , Lactose/metabolism , Milk/chemistry , Plant Oils/pharmacology , Poaceae , Rumen/drug effects , Rumen/microbiology , SilageABSTRACT
BACKGROUND: Patients with carcinomas of the upper aero-digestive tract often suffer from ear pain as a tumor associated syndrome. This prospective study examines the predictive and prognostic value of this symptom. PATIENTS AND METHODS: Ninety-six consecutive patients who completed a locally radiotherapy of a carcinoma of the oropharynx were prospectively evaluated and followed. Forty-nine out of 96 patients stated the symptom, either spontaneously or after questioning. The 2 groups showed no difference regarding TNM-classification, histology and total dose. Overall survival, local control and disease specific survival were calculated according to Kaplan-Meier and compared by the log-rank test. RESULTS: A clinically complete remission was obtained in significantly fewer patients with reflex-otalgia as compared to patients without reflex-otalgia, 61.2% versus 89.3%, p < 0.002. Local control of patients with reflex-otalgia was significantly less with 49%, mean follow-up 564 days, in comparison to local control in patients without reflex-otalgia, mean follow-up 613 days, p = 0.01. Disease specific survival was significantly worse for patients with reflex-otalgia, p < 0.012. The probability of local control of T1/T2 tumors with reflex-otalgia was similar to T3/T4 tumors without reflex-otalgia. Local control for all tumor categories combined is 74% for patients without reflex-otalgia versus 49% for patients with reflex-otalgia. CONCLUSION: In our patients, reflex-otalgia is a new and statistically significant parameter for the probability of local control and disease specific survival.
Subject(s)
Carcinoma, Squamous Cell/radiotherapy , Earache/radiotherapy , Oropharyngeal Neoplasms/radiotherapy , Paraneoplastic Syndromes/radiotherapy , Reflex, Abnormal/radiation effects , Adult , Aged , Aged, 80 and over , Carcinoma, Squamous Cell/mortality , Carcinoma, Squamous Cell/pathology , Earache/mortality , Earache/pathology , Female , Humans , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Staging , Oropharyngeal Neoplasms/mortality , Oropharyngeal Neoplasms/pathology , Paraneoplastic Syndromes/mortality , Paraneoplastic Syndromes/pathology , Prognosis , Prospective Studies , Radiotherapy, High-Energy , Survival AnalysisABSTRACT
Although relatively uncommon in daily clinical practice, calcification may be found in inflammatory hepatic lesions and in benign and malignant liver neoplasms. The most common source of calcified hepatic lesions is inflammatory conditions such as granulomatous diseases (e.g., tuberculosis). The calcification typically involves the entire lesion and appears as a dense mass that can produce artifacts on computed tomographic (CT) scans. Echinococcus cysts have curvilinear or ring calcification. Hemangiomas, especially large ones, may contain large, coarse calcifications that are centrally located in areas of fibrosis; these may be seen at CT (20% of cases) or radiography (10%). In hepatocellular adenoma, calcifications may be solitary or multiple and are usually located eccentrically within a complex heterogeneous mass. Calcifications in fibrolamellar carcinoma have been reported in 15%-25% of cases at CT and occur in a wide variety of patterns. Calcifications in intrahepatic cholangiocarcinoma are typically accompanied by a desmoplastic reaction and are visible at CT in about 18% of cases. Calcified hepatic metastases are most frequently associated with mucin-producing neoplasms such as colon carcinoma. Knowledge of the pathologic features of each entity helps radiologists to better recognize the shape, size, density, number, location, and distribution of hepatic calcifications seen on images and to narrow the differential diagnosis.
Subject(s)
Calcinosis/diagnostic imaging , Granuloma/diagnostic imaging , Liver Diseases/diagnostic imaging , Liver Neoplasms/diagnostic imaging , Calcinosis/parasitology , Calcinosis/pathology , Granuloma/pathology , Humans , Liver Diseases/pathology , Liver Neoplasms/pathology , Liver Neoplasms/secondary , Tomography, X-Ray ComputedABSTRACT
PURPOSE: To determine the characteristic diagnostic features of necrotizing fasciitis and to evaluate the role of computed tomography (CT) in its management. MATERIALS AND METHODS: Fourteen patients with surgically proved necrotizing fasciitis of the extracranial head and neck were examined with contrast material-enhanced CT. Clinical, radiologic, surgical, pathologic, and anatomic findings at admission and after initial treatment were analyzed retrospectively. RESULTS: Constant CT features of necrotizing fasciitis were diffuse thickening and infiltration of the cutis and subcutis (cellulitis); diffuse enhancement and/or thickening of the superficial and deep cervical fasciae (fasciitis); enhancement and thickening of the platysma, sternocleidomastoid muscle, or strap muscles (myositis); and fluid collections in multiple neck compartments. Inconstant CT features included gas collections, mediastinitis, and pleural or pericardial effusions. All patients underwent extensive surgical debridement. Follow-up CT scans in 11 patients revealed clinically unsuspected progression of the inflammatory process in previously unaffected areas, a finding that warranted additional surgery in nine patients. Twelve patients survived, and two patients died of septic shock and aspiration pneumonia despite intensive surgical and medical treatment. CONCLUSION: Early recognition of necrotizing fasciitis with CT enables appropriate surgical treatment. CT may also be a useful guide in further patient treatment after initial surgical debridement.