Changes In Fluid Composition Research Articles

Experimental Investigation of the Impacts of Fracturing Fluid on the Evolution of Fluid Composition and Shale Characteristics: A Case Study of the Niutitang Shale in Hunan Province, South China

Hydraulic fracturing is a widely used technique for oil and gas extraction from ultra-low porosity and permeability shale reservoirs. During the hydraulic fracturing process, large amounts of water along with specific chemical additives are injected into the shale reservoirs, causing a series of reactions the influence the fluid composition and shale characteristics. This paper is focused on the investigation of the geochemical reactions between shale and fracturing fluid by conducting comparative experiments on different samples at different time scales. By tracking the temporal changes of fluid composition and shale characteristics, we identify the key geochemical reactions during the experiments. The preliminary results show that the dissolution of the relatively unstable minerals in shale, including feldspar, pyrite and carbonate minerals, occurred quickly. During the process of mineral dissolution, a large number of metal elements, such as U, Pb, Ba, Sr, etc., are released, which makes the fluid highly polluted. The fluid–rock reactions also generate many pores, which are mainly caused by dissolution of feldspar and calcite, and potentially can enhance the extraction of shale gas. However, precipitation of secondary minerals like Fe-(oxy) hydroxides and CaSO4 were also observed in our experiments, which on the one hand can restrict the migration of metal elements by adsorption or co-precipitation and on the other hand can occlude the pores, therefore influencing the recovery of hydrocarbon. The different results between the experiments of different samples revealed that mineralogical texture and composition strongly affect the fluid-rock reactions. Therefore, the identification of the shale mineralogical characteristics is essential to formulate fracturing fluid with the lowest chemical reactivity to avoid the contamination released by flowback waters.

Assessment of CO2 trapping mechanisms in partially depleted oil-bearing sands

The objective of this work is to evaluate various CO2 sequestration mechanisms occurring in the Morrow B Sandstone in the Farnsworth Unit. A history-matched numerical simulation model was created using extensive geological, petrophysical, and operational data collected from the field. The numerical model is competent to investigate the impact of residual, structural-stratigraphic, solubility, and mineral trapping mechanisms on the fluid transportation dynamics and petrophysical property variations. The model forecasts the field response of 20 years of WAG injections. Afterward, all wells were shut-in, and the reservoir was allowed to evolve for 1000 years to investigate the fate of injected CO2. In this paper, we assess the impacts of various trapping mechanisms on oil recovery and CO2 storage efficacy. By analyzing the results reported from the numerical simulation model, the in-situ fluid composition and mineralogy changes are also investigated. More importantly, we seek to confirm the petrophysical property variations due to the CO2 injection with observations from laboratory measurements. The experiences gained from this study provide valuable insights regarding physiochemical storage induced by the CO2 injection activities and serve as a benchmark case for future CO2 enhanced oil recovery (EOR) projects involving reactive solute transport.

P1616ASSESSMENT OF SEQUENTIAL CHANGES OCCURRING IN THE BODY FLUID COMPOSITION BY BIO-IMPEDANCE ANALYSER IN PRE AND EARLY POST RENAL TRANSPLANT PATIENTS

Abstract Background and Aims Chronic kidney disease is now recognized as major causes of death in India. The Global Burden of Disease (GBD) study 2015, ranked chronic kidney disease as 17th among the causes of deaths globally (age standardized annual death rate of 19·2 deaths per 100 000 population). Deaths due to renal failure constituted 2·9% of all deaths in 2010–13 among 15–69 year-olds, an increase of 50% from 2001–03. These are varies metabolic derangements in CKD patients, among which volume overload is the major problem contributing uncontrolled hypertension and increases cardiovascular mortality. There will be increased total body water (TBW) and extracellular water (ECW) at the expense of reduced intracellular water (ICW). Renal replacement therapies such as dialysis or kidney transplantation are the major treatment modalities. Renal transplantation is the treatment of choice for end stage renal failure patients. Despite improving renal dysfunction, patients are at risk for existing or new onset of conditions after transplantation and may alter the body fluid physiology. Till date, renal transplant patients received little attention towards fluid balance and nutritional status. There are many studies supporting the use of bioimpedance analyzer as a reliable tool in assessing the fluid status in haemodialysis patients, but there are very few studies done in post renal transplant patients to know their fluid status with single functioning kidney where Glomerular filtration rate are generally much lower than normal. Method fifty renal transplant recipients were followed in our centre for 6 months (68 males, maximum were in 31-45years of age). Biochemical parameters like haemoglobin, urea, creatinine, electrolytes, albumin, estimated glomerular filtration rate (eGFR); TBW, ECW, ICW and over hydration (OH) measured using bioimpedance analysis (BCM, Fresenius) were evaluated at baseline (pre-transplant) and after transplant at 3 and 6 months. Baseline biochemical and bio-impedance values were compared with 3 and 6 months post transplant. Patients were divided into 3 sub-groups based on eGFR: good graft function (eGFR >60 ml/min), borderline graft function (eGFR 30-60 ml/min) and severe graft dysfunction (eGFR >30 ml/min/1.73m2). TBW, ECW, OH and ICW were compared between the sub groups of eGFR at 3 and 6 months post transplant. Results Comparing before transplant with 3 and 6 months post-transplant, TBW, ECW and OH were reduced while ICW increased significantly with good graft function. On comparing 3 months to 6 months post-transplant, ECW, TBW, OH reduced further but there was not much difference in ICW. OH at 6 months post-transplant was 0.6 L (within normal range of gender-matched individuals from the reference population, that is, −1.1 to 1.1 L). In patients with severe graft dysfunction (<30ml/min), TBW, ECW and OH were remained high when compared to borderline (31-60ml/min) and with good graft function group (>60ml/min). Biochemical improvement was comparable with bio-impedance parameters at 3 months and 6 months post transplant with good graft function. Conclusion The BIA showed significant reduction in TBW, ECW and OH by 6 months post transplant and ICW increased as graft function improved post transplantation by 3 months and thereafter, change was not significant. Parameters of Bio-impedance analyzer of well-functioning kidney transplant recipients showed that the altered body water compartments quickly normalizes which is never achieved by a hemodialysis session. We found that Bio-impedance analyzer was useful to know the changes in body fluid composition in post renal transplant patients.

Effect of high-salt diet on blood pressure and body fluid composition in patients with type 1 diabetes: randomized controlled intervention trial

IntroductionPatients with type 1 diabetes are susceptible to hypertension, possibly resulting from increased salt sensitivity and accompanied changes in body fluid composition. We examined the effect of a high-salt diet...

Texture and composition of magnetite in the Duotoushan deposit, NW China: implications for ore genesis of Fe–Cu deposits

AbstractThe Duotoushan deposit is an important Fe–Cu deposit in the Aqishan–Yamansu metallogenic belt of eastern Tianshan, NW China. Magnetite occurs in two main habits which are common in many Fe–Cu deposits, i.e. platy (TD1 Mag) and granular magnetite (TD2 Mag) have been identified at Duotoushan. Platy magnetite shows two different zones (bright and dark) based on the observations by scanning electron microscopy. The bright part (TD1-L) is the main part of TD1 magnetite and lacks inclusions. The dark part (TD1-D) is very porous and has abundant tiny silicate inclusions. Granular magnetite is usually anhedral with obvious oscillatory zoning in back-scattered electron images. In general, the dark zones of magnetite are characterised by greater Si, Ca, Al and lesser Fe contents than the bright zones. In situ X-ray diffraction (XRD) analysis shows that the lattice parameter of TD1 magnetite is approximately equal to that of standard magnetite and slightly higher than that of TD2 magnetite, indicating that some cations with ionic radii smaller than those of Fe2+ or Fe3+ entered the magnetite lattice by simple or coupled substitution mechanisms in TD2 magnetite.The results in the present study show that the effects of temperature and $f_{{\rm O}_ 2}$ on platy magnetite are very limited and the changing fluid composition might be the major controlling factor for the formation of Duotoushan platy magnetite. Although the possibility that mushketovite transformed from hematite cannot be excluded entirely, evidence from in situ XRD data, pore-volume ratio calculation and the growth habit of intergrown minerals indicates that platy magnetite (TD1) coexisting with amphibole was more likely to have been precipitated originally from hydrothermal fluid. This was then affected by changes in the fluid composition which consequently led to dissolution of primary magnetite (TD1-L) and re-precipitation of TD1-D magnetite (with abundant porosity and mineral inclusions). Meanwhile, granular magnetite (TD2) with oscillatory zoning, and coexisting with epidote and quartz, was precipitated from fluid with periodic variation in temperature. These oscillatory zones are characterised by bands enriched in Si, Al and Ca alternating with bands depleted in these elements. The present investigation revealed a complex evolutionary process for magnetite formation in the Duotoushan deposit. The importance of combined investigation of texture and compositional characterisation of magnetite for study of the ore genesis and evolution of Fe–Cu deposits is highlighted.

Influence of orthodontic treatment with removable devices in children on the properties of oral fluid

Relevance. The present article provides data regarding changes in the oral cavity during orthodontic tratment with custom-made removable appliances. Purpose. To study the condition of the oral cavity in children aged 7-12 with dentoalveolar abnormalities during treatment with removable orthodontic appliances.Materials and methods. 110 patients aged 7-12 were examined in Nakhodka, Russia. Group I – control (34 subjects) with no dentoalveolar pathology. Group II – children with dentoalveolar pathology (74 subjects), undergoing orthodontic treatment. Besides clinical examination the following laboratory tests were taken, namely: saliva viscosity, saliva PH, saliva buffer capacity, microcrystallography of saliva. Type III prevailed in 60% of cases. Results. Caries intensity during orthodontic treatment was detected to increase up to 8.32 ± 0.28 in comparison with control group 6.57 ± 0.22 (p < 0.05). Hygiene rate decreased in experimental group to 2.8 ± 0.08, in comparison with controls – 1.40 ± 0.02 (p < 0.05). Salivary PH decreased during orthodontic treatment. Microcrystallization type III of saliva prevailed in 60% of cases.Conclusions. The study revealed strong relationship between orthodonotic treatment with removable appliances and physicochemical properties of mixed saliva r = 0.95 (p < 0.05). Appropriate approach and timely preventive measures can help correct oral condition in orthodontic treatment. Despite changes in oral fluid composition, esthetic and functional result of treatment with orthodontic customized removable appliances was high.

Quantifying the volume increase and chemical exchange during serpentinization

AbstractQuantifying the concurrent changes in rock volume and fluid composition during serpentinization remains a major challenge in assessing its physicochemical effects during continental rifting, seafloor spreading, and subduction. Here we conducted a series of 11 hydrothermal laboratory experiments where cylindrical cores of natural dunite, harzburgite, and pyroxenite were reacted with an aqueous solution at 300 °C and 35 MPa for up to 18 months. Using three-dimensional microcomputed tomography and thermogravimetry, we show that rock volume systematically increased with time and extent of reaction, leading to a volume increase of 44% (±8%) in altered rock domains after 10–18 months of serpentinization. The volume expansion was accompanied by Mg-Ca exchange between fluid and rock, while Fe and Si were largely conserved. We find that the protolith composition (olivine/orthopyroxene ratio) plays a significant role in controlling the fluid chemistry and the proportions of hydrous secondary minerals during serpentinization. Agreement between alteration mineralogy, composition of reacting fluids, and measured volume changes suggests that serpentinization under static conditions is a volume-increasing process in spite of demonstrable mass transfer. Volume expansion implies an increased water carrying capacity and buoyancy force of serpentinite per unit mass of protolith, while Mg-Ca exchange during serpentinization may affect the Mg/Ca ratio of seawater on Earth and possibly other ocean worlds.

Post-inhalation cough with therapeutic aerosols: Formulation considerations.

This review provides an assessment of post-inhalation cough with therapeutic aerosols. Factors that increase cough may be mitigated through design of the drug, formulation, and device. The incidence of cough is typically less than 5% for drugs with a nominal dose less than 1mg, including asthma and COPD therapeutics. Cough increases markedly as the dose approaches 100mg. This is due to changes in the composition of epithelial lining fluid (e.g., increases in osmolality, proton concentration). Whether an individual exhibits cough depends on their degree of sensitization to mechanical and chemical stimuli. Hypersensitivity is increased when the drug, formulation or disease result in increases in lung inflammation. Cough related to changes in epithelial lining fluid composition can be limited by using insoluble neutral forms of drugs and excipients.

Skarn formation and tin enrichment during regional metamorphism: The Hämmerlein polymetallic skarn deposit

The Hämmerlein Sn-rich polymetallic skarn deposit (Erzgebirge, Germany), which is hosted by Variscan schists and gneisses, includes garnet, amphibole, pyroxene, and magnetite skarns that formed during regional metamorphism at ∼340 Ma. The skarn deposit was overprinted during the intrusion of the ca. 320 Ma Eibenstock granite. Tin was introduced into the system during regional metamorphism at 340 Ma (Sn mostly hosted in silicate minerals) and after the intrusion of the Eibenstock granite at c. 320 Ma (Sn hosted in cassiterite). The emplacement of late stage melts of the Eibenstock granite also resulted in the formation of cassiterite-quartz veins in the schists hosting the Hämmerlein skarns and at some distance in the formation of several cassiterite greisen.Major, trace, and rare earth element data of the skarn units and their hosts rocks demonstrate that skarns formed from impure carbonates with variable proportions of silicate minerals. Depending on the original modal compositions of the skarns and their host rocks, the mineralizing fluid selectively added and removed elements, which resulted for the skarns and the schist ore in a general enrichment in Sn, In, Cu, and W and a noticeable depletion in Al and Sr. The Sr, Nd, and Pb isotopic composition of the skarns, schists, and gneisses resembles those of the metamorphic rocks of the Erzgebirge rather than those of the granites, possibly indicating that the geochemical signature of granite-derived fluids had been severely altered during fluid-rock interaction before these fluids reached the skarns, schists, and gneisses. Similarly, the Li and B isotopic composition of the skarn samples reflects the likely range of possible source rocks for metamorphic fluids, rather than the composition of the granite-derived fluid. In contrast, the Li and B signature of greisen samples shows a variable mixture of material derived from the granite and the metasedimentary rocks, respectively.Our data show that a first Sn enrichment took place when the Paleozoic sedimentary rocks were affected by regional metamorphism at ca. 340 Ma. Fluids derived from these siliciclastic sedimentary protoliths mobilized and transported Sn and Fe. These fluids reacted with the impure carbonates, resulting in decarbonation and the formation of calc-silicate minerals and biotite in the various skarn types. The changing fluid composition as well as the incorporation of Fe in skarn silicates and formation of Fe-oxides resulted in the incorporation of Sn into silicate minerals. During or after the emplacement of the Eibenstock granite, the original skarn was to a variable extent retrogressed and Sn was released from Sn-bearing calc-silicates and biotite. During this event additional Sn was added to the skarn and the hosting schists. Released Sn and newly added Sn precipitated as cassiterite.

Textures and Chemical Compositions of Magnetite from Iron Oxide Copper-Gold (IOCG) and Kiruna-Type Iron Oxide-Apatite (IOA) Deposits and Their Implications for Ore Genesis and Magnetite Classification Schemes

AbstractTextural and compositional data of magnetite from Igarapé Bahia, Alemao, Sossego, Salobo, and Candelaria iron oxide copper-gold (IOCG) and El Romeral Kiruna-type iron oxide-apatite (IOA) deposits show that some magnetite grains display oscillatory zoning or have been reequilibrated by oxy-exsolution, coupled dissolution and reprecipitation (CDR) reactions, and/or recrystallization. Textures formed via CDR are most widespread in the studied samples. The original oscillatory zoning was likely derived from the crystal growth during fluctuating fluid compositions rather than from variation in temperature and oxygen fugacity. The oxy-exsolution of ilmenite in magnetite is attributed to increasing oxygen fugacity and decreasing temperature with alteration and mineralization, resulting in product magnetite with lower Ti and higher V contents. Recrystallization of some magnetite grains is commonly due to high-temperature annealing that retained primary compositions. Two different types of CDR processes are defined according to textures and chemical compositions of different generations of magnetite. The first generation of magnetite (Mag-1) is an inclusion-rich and trace element-rich core, which was replaced by an inclusion-poor and trace element-poor rim (Mag-2). The third generation of magnetite (Mag-3), inclusion poor but trace element rich, occurs as veins replacing Mag-2 along fractures or grain margins. Type 1 CDR process transforming Mag-1 to Mag-2 is more extensive and is similar to processes reported in skarn deposits, whereas type 2 CDR process is local, transforming Mag-2 to Mag-3. During type 1 CDR process, minor and trace elements Si, K, Ca, Mg, Al, and Mn in magnetite are excluded, and Fe contents increase to various extents, in contrast to type 2 CDR process, which is characterized by increased contents of Si, K, Ca, Mg, Al, and Mn. Type 1 CDR process is possibly induced by the changing fluid composition and/or decreasing temperature during progressive alteration and ore formation, whereas type 2 CDR process can be interpreted as post-ore replacement due to a new pulse of magmatic-hydrothermal fluids.The identification of magnetite core (Mag-1) with igneous origin and rim (Mag-2) with magmatic-hydrothermal origin in the Sossego IOCG and El Romeral IOA deposits supports a fluid changing from magmatic to magmatic-hydrothermal during IOCG and IOA formation and indicates a genetic link between these two deposit types. The large data set here further demonstrates that magnetite is susceptible to textural and compositional reequilibration during high-temperature magmatic and magmatic-hydrothermal processes. Reequilibrated magnetite, particularly that formed by CDR processes, has a chemical composition that can be different from that of primary magnetite. Modified magnetite, therefore, cannot be used to discriminate its primary origin or to interpret its provenance in overburden sediments. Therefore, in situ chemical analysis of magnetite combined with textural characterization is necessary to understand the origin of magnetite in IOCG and IOA deposits.

Progressive changes in human follicular fluid composition over the course of ovulation: quantitative proteomic analyses

Follicular fluid (FF) acts as a vehicle for paracrine signalling between somatic cells of the follicle and the oocyte. To investigate changes in the protein composition of FF during ovulation, we conducted a prospective cohort study including 25 women undergoing fertility treatment. Follicular fluid was aspirated either before or 12, 17, 32 or 36 h after induction of ovulation (five patients per time point). Liquid chromatography-mass spectrometry was used to identify and quantify FF proteins. In total, 400 proteins were identified and the levels of 40 proteins changed significantly across ovulation, evaluated by analysis of covariance (adjusted p < 0.05) and on-off expression patterns. The majority peaked after 12–17 h, e.g., AREG (p < 0.0001), TNFAIP6 (p < 0.0001), and LDHB (p = 0.0316), while some increased to peak after 36 h e.g., ACPP (p < 0.0001), TIMP1 (p < 0.0001) and SERPINE1 (p = 0.0002). Collectively, this study highlights proteins and pathways of importance for ovulation and oocyte competence in humans.

Unusual Mineral Diversity in a Hydrothermal Vein-type Deposit: the Clara Mine, SW Germany, as a Type Example

AbstractThe Clara baryte-fluorite-(Ag-Cu) mine exploits a polyphase, mainly Jurassic to Cretaceous, hydrothermal unconformity vein-type deposit in the Schwarzwald, SW Germany. It is the type locality for 13 minerals, and more than 400 different mineral species have been described from this occurrence, making it one of the top five localities for mineral diversity on Earth.The unusual mineral diversity is mainly related to the large number and diversity of secondary, supergene, and low-temperature hydrothermal phases formed from nine different primary ore-gangue associations observed over the last 40 years; these are: chert/quartz-hematite-pyrite-ferberite-scheelite with secondary W-bearing phases; fluorite-arsenide-selenide-uraninite-pyrite with secondary selenides and U-bearing phases (arsenates, oxides, vanadates, sulfates, and others); fluorite-sellaite with secondary Sr- and Mg-bearing phases; baryte-tennantite/tetrahedrite ss-chalcopyrite with secondary Cu arsenates, carbonates, and sulfates; baryte-tennantite/tetrahedrite ss-polybasite/pearceite-chalcopyrite, occasionally accompanied by Ag±Bi±Pb-bearing sulfides with secondary Sb oxides, Cu arsenates, carbonates, and sulfates; baryte-chalcopyrite with secondary Fe- and Cu-phosphates; baryte-pyrite-marcasite-chalcopyrite with secondary Fe- and Cu-sulfates; quartz-galena-gersdorffite-matildite with secondary Pb-, Bi-, Co-, and Ni-bearing phases; and siderite-dolomite-calcite-gypsum/anhydrite-quartz associations.The first eight associations are of Jurassic to Cretaceous age and are related to at least eight different pulses of hydrothermal fluids (plus the meteoric fluids responsible for supergene oxidation); the last association is of Neogene age. Spatial juxtaposition of the various primary associations produces overlaps of the secondary associations. In addition to natural oxidation processes, two anthropogenic additions led to specific mineral associations: (1) lining of the adit walls with concrete resulted in high-pH assemblages of mainly Ca-rich phases, including arsenates and sulfates; and (2) the addition of hydrofluoric acid to counterbalance the high-pH fluids produced by power plant ashes introduced into the exploited parts of the mine resulted in fluoride assemblages of alkali and alkaline earth metals.This contribution describes for the first time all types of assemblages and associations observed and physicochemical considerations and models of formation for some of the supergene associations. The meteoric fluids responsible for element mobilization and redistribution, and for the formation of new, secondary phases, interacted with wall rocks prior to and during percolation through the actual hydrothermal associations. Depending on the amount of reaction with ore, gangue, and host rock phases, the chemical composition of the meteoric fluids and its redox potential may vary over short distances. Hence different mineral assemblages and zoned associations record fluid compositional changes, even on the millimeter to centimeter scale. Unusual mineral diversity at the Clara mine therefore develops from a combination of diverse primary hydrothermal mineralization stages, an unusual number of fluid flow events involving compositionally different fluids, and local equilibrium conditions that change within centimeters during supergene processes involving meteoric fluids and anthropogenic additions.

Textural evolution and trace element chemistry of hydrothermal calcites from Archean gold deposits in the Hattu schist belt, eastern Finland: Indicators of the ore-forming environment

Orogenic style gold mineralizations in the Archean Hattu schist belt (E Finland) are present in all major host rock lithologies including epiclastic sedimentary rocks, volcanic rocks, and felsic intrusives. The gold deposits are related to extensive quartz-dominated vein networks and the gold mineralization occurs as dissemination in altered wall rocks and within hydrothermal quartz veins. The quartz-dominated veins frequently contain calcite, which is also present within the country rocks. We analyze and compare the major and trace element chemistry of these calcites and test whether they carry the signatures of the origin of hydrothermal fluids associated with the gold deposits or record fluid interaction with the local wall rocks. The calcites show textural growth and chemical zoning, considerable chemical variations within samples and the chemical data do show some overlap between the samples. All calcites contain dominantly Ca with other elements being typically below 2 wt%, and they are accordingly classified as rather pure calcites. Amongst minor elements, both Mg and Fe show larger variations than Mn. The concentrations of most trace elements analyzed are relatively low, except for Sr and Y, which can attain values up to 1 wt% and 200 ppm, respectively. Some of the trace elements or trace element ratios in hydrothermal calcite, including Sr, Y, Mn, (La/Lu)N and ∑REE, show correlations with the respective host rock lithologies. This indicates that interaction between hydrothermal fluids and adjacent and diverse host rocks has strongly affected the trace element chemistry of calcite. Chemically variable growth zones in large calcite crystals and distinct grain populations within individual samples cannot be readily explained by host rock control, but instead they are interpreted to reflect changes in fluid composition over time. The hydrothermal calcites have chondrite-normalized REE patterns that are mostly HREE enriched relative to LREE, with very few exceptions that show unfractionated flat or LREE enriched (relative to the HREE) patterns. The REE patterns of the calcites are very different from those of their immediate host rocks, suggesting that they are inherited from the hydrothermal fluid(s) from which they precipitated. The HREE enrichment relative to the LREE visible in the patterns resembles the REE patterns of calcites from hydrothermal vein type deposits of metamorphic origin elsewhere and contrasts with the REE patterns of calcites from magmatic-hydrothermal environments. The REE patterns of the hydrothermal calcites in the Hattu schist belt deposits would therefore be compatible with formation from a fluid system that is essentially derived from metamorphic sources, in agreement with conclusions drawn from the fluid inclusion chemistry.

Reactive fluid infiltration along fractures: Textural observations coupled to in-situ isotopic analyses

Fluid-rock interaction occurred in hydrothermal veins in dolomitic wall pendants during cooling of the Bruffione granodiorite (Adamello batholith, Italy). These veins formed through fluid infiltration along a central fracture, and the fluid reacted with the dolomite to precipitate forsterite + calcite in cm-wide replacement zones through SiO2 metasomatism. Textural observations have been coupled to in-situ stable isotope and chemical analysis of dolomite, calcite and forsterite to show that stable isotope exchange occurs only through mineral reaction and recrystallization. We identified two distinct reaction regimes; (1) a regime dominated by net transfer reactions, which is characterized by the complete dissolution of dolomite and the formation of the new vein minerals (i.e. forsterite + calcite) close to the open fracture. The driver of the reaction is the large chemical disequilibrium introduced by infiltration of fluid of magmatic origin. And (2) a regime dominated by the dissolution and reprecipitation of dolomite more distal to the central fracture. The dolomite protolith is partially dissolved along grain boundaries, but also trough the grains which are being fragmented, and reprecipitation of newer generations of dolomite rims occur. A progressive change in fluid composition is detected with increasing distance from the vein. In comparison to the first regime, the system is rock-dominated, and only small amounts of fluids and small chemical disequilibrium at the trace element level are suggested to be the drivers for this reaction. A fundamental understanding of mineral reactions in the presence of fluids is necessary for many areas of science and industry, and recrystallization reactions driven by very small chemical disequilibrium as described here are important to be identified and integrated into reactive transport models. In fact, for this case study, the fluid-rock interaction volume would be largely underestimated if only the net transfer reaction zone is considered. This could be crucial for safety evaluations in technical applications.

Apatite as a tracer of the source, chemistry and evolution of ore-forming fluids: The case of the Olserum-Djupedal REE-phosphate mineralisation, SE Sweden

Abstract This study explores the suitability of apatite as a tracer of the source(s), chemistry, and evolution of ore-forming hydrothermal fluids. This is tested by analysing the halogen (F, Cl, Br, and I), stable Cl isotopic, and trace element compositions of fluorapatite from the regional-scale Olserum-Djupedal rare earth element (REE) phosphate mineralisation in SE Sweden, which is dominated by monazite-(Ce), xenotime-(Y), and fluorapatite. The primary hydrothermal fluid flow system is recorded in a sequence from proximal granite-hosted to distal metasediment-hosted fluorapatite. Along this sequence, primary fluorapatite shows a gradual increase of Cl and Br concentrations and in (Gd/Yb)N, a decrease of F and I concentrations, a decrease in δ37Cl values, in (La/Sm)N, and partly in (La/Yb)N and (Y/Ho)N. Local compositional differences of halogen and trace element concentrations have developed along rims and in domains adjacent to fractures of fluorapatite due to late-stage partial reaction with fracture fluids. These differences are insignificant compared to the larger deposit-scale zoning. This suggests that apatite can retain the primary record of the original ore-forming fluid despite later overprinting fluid events. The agreement between Br/Cl and I/Cl ratios of apatite and those of co-existing fluid inclusions at lower temperatures indicates that only a minor fractionation of Br from I occurs during apatite precipitation. The halogen ratios of apatite can thus be used as a first-order estimate for the composition of the ore-forming fluid. Taking the small fractionation factors for Cl isotopes between apatite and co-existing fluid at high temperatures into account, we propose that the Cl isotopic composition of apatite and the halogen ratios derived from the apatite composition can be used jointly to trace the source(s) of ore-forming fluids. By contrast, most trace elements incorporated in apatite are affected by the host rock environment and by fluid-mineral partitioning due to growth competition between co-crystallising minerals. Collectively, apatite is sensitive to changing fluid compositions, yet it is also able to record the character of primary ore-forming fluids. Thus, apatite is suitable for tracing the origin, chemistry, and evolution of fluids in hydrothermal ore-forming settings.

Temporal changes in synovial fluid composition and elastoviscous lubrication in the equine carpal fracture model.

The objective of this study was to examine temporal variations in synovial fluid composition and lubrication following articular fracture. Post-traumatic osteoarthritis (PTOA) was induced by creating an osteochondral fracture in the middle carpal joint of four horses while the contralateral limb served as a sham-operated control. Horses were exercised on a high-speed treadmill, and synovial fluid was collected pre-operatively and at serial timepoints until 75 days post-operatively. Lubricin and hyaluronic acid (HA) concentrations were measured using sandwich ELISAs, and the molecular weight distribution of HA was analyzed via gel electrophoresis. Synovial fluid viscosity and cartilage friction coefficients across all modes of lubrication were measured on days 0, 19, 33, and 61 using a commercial rheometer and a custom tribometer, respectively. HA concentrations were significantly decreased post-operatively, and high molecular weight HA (>6.1MDa) did not recover to pre-operative values by the study termination at day 75. Lubricin concentrations increased after surgery to a greater extent in the OA as compared to sham-operated limbs. Viscosity was significantly reduced after surgery. While boundary and elastoviscous mode friction coefficients did not vary, the transition number, representing the shift between these modes, was lower. Although more pronounced in the OA limbs, similar derangements in HA, HA molecular weight distribution, viscosity, and transition number were observed in the sham-operated limbs, which may be explained by synovial fluid washout during arthroscopy. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Changes of follicular fluid composition during estrous cycle: The effects on oocyte maturation and embryo development in vitro

Oocytes are bathed in extracellular fluid of the antral follicles, which is termed follicular fluid (FF). Follicular fluid is synthesized from secretions of theca, granulosa, and cumulus cells and from a transudate of blood plasma. Oocytes persist in meiotic arrest in antral follicles until luteinizing hormone (LH) surge or removal the oocytes from the ovarian follicles. This suggests that FF before LH surge might contain meiosis inhibiting factor(s). The microvasculatory bed of the follicular wall and the composition of FF undergo changes during follicular growth and development, which is important for oocyte maturation and subsequent embryo development. Therefore, it is expected that FF composition and components might change according to timing of FF aspiration from follicles. Hence, negative or positive effects could be expected when FF supplemented during oocyte maturation in vitro. Nutrition effects on microvasculatory bed of follicles and their sizes. Thus, the nutritional status of animals is a factor affected on oocyte maturation and embryo development. The present article reviews and discusses these effects.

Wound fluid of rats fed protein-free diets delays wound healing through the suppression of the IGF-1/ERK(1/2) signaling pathway.

Adequate nutrition is required to maintain healthy skin integrity, and malnourished patients with poor protein diet often experience delayed wound healing. Understanding the cellular mechanisms of protein malnutrition will justify the importance of optimal protein diets in health and disease defense. Therefore in the present study, we examined the effects of changes in wound fluid composition and its function caused by protein malnutrition on wound healing. Rats were fed a control (CO; 20% protein) diet or a protein-free (PF) diet for 2weeks; we then created full-thickness wounds on the dorsolateral skin. On day 5 after wounding, frozen sections of the wounds were created to investigate the state of granulation tissues, and wound fluid obtained from the rats was collected to examine variations in cytokine levels and its function. Wound closure was significantly delayed from day 4 until total wound closure in rats fed a PF diet. Thickness of granulation tissue, which is composed of mainly dermal fibroblasts, and Ki67 immunohistochemical staining were significantly decreased in rats fed PF diets. PF diets decreased insulin-like growth factor (IGF)-I, which promotes wound healing, and increased IGF-binding protein-1, which inhibits IGF-I bioavailability, in wound fluid. Wound fluid obtained from rats fed a PF diet suppressed dermal fibroblast proliferation. Furthermore, the wound fluid remarkably decreased the phosphorylation level of IGF-I receptor β (IGF-IR) and extracellular signal-regulated kinase (ERK)(1/2) in dermal fibroblasts. These results show that wound fluid of rats fed PF diets delays wound healing by inhibiting granulation tissue formation through the suppression of the IGF-1/ERK(1/2) signaling pathway.

Improved material balance equation (MBE) for gas-condensate reservoirs considering significant water vaporization

The phenomenon of retrograde condensation occurs when the reservoir pressure declines below the dew-point pressure causing gas condensation and developing two-phase flow. Material balance equation (MBE) of gas condensate reservoirs is a real challenge because of the change in fluid composition and complexity of phase behavior.Neglecting the effect of water vaporization may lead to inaccurate predictions of the material balance equation. Therefore, the main objective of this study is to develop an improved MBE model capable to describe gas condensate reservoirs under significant vaporization of connate water and water influx driving mechanism.A new parameter is developed to consider water vaporization. This parameter is used to derive equations for gas condensate reservoirs considering vaporization effect with and without consideration of water influx. Numerical examples have been developed and used to compare the accuracy of the newly-developed model with conventional ones using actual reservoir depletion and production data.The results indicated that water vaporization has an important effect and should be considered for accurate MBE predictions. Error analysis showed that the newly-developed equations are more accurate than previously-developed models. The accuracy of the new MBE is attributed to the additional parameter introduced considering high pressure and high temperature conditions.The application of the new material balance equation will have important impact on predictions of initial gas in place, reserve calculation and future simulation studies.

Evolution of metamorphic fluid recorded in granulite facies metacarbonate rocks from the middle segment of the Mogok metamorphic belt in central Myanmar

AbstractThe Mogok metamorphic belt of Palaeogene age, which records subduction‐ and collision‐related events between the Indian and Eurasian plates, lies along the western margin of the Shan plateau in central Myanmar and continues northwards to the eastern Himalayan syntaxis. Reaction textures of clinohumite‐ and scapolite‐bearing assemblages in Mogok granulite facies metacarbonate rocks provide insights into the drastic change in fluid composition during exhumation of the collision zone. Characteristic high‐grade assemblages of marble and calcsilicate rock are clinohumite+forsterite+spinel+phlogopite+pargasite/edenite+calcite+dolomite, and scapolite+diopside+anorthite+quartz+calcite respectively. Calculated petrogenetic grids in CaO–MgO–Al2O3–SiO2–H2O–CO2 and subsets of this system were employed to deduce the pressure–temperature–fluid evolution of the clinohumite‐ and scapolite‐bearing assemblages. These assemblages suggest higher temperature (&gt;780–810°C) and [=CO2/(CO2+H2O) &gt;0.17–0.60] values in the metamorphic fluid for the peak granulite facies stage, assuming a pressure of 0.8 GPa. Calcite grains commonly show exsolution textures with dolomite particles, and their reintegrated compositions yield temperatures of 720–880°C. Retrograde reactions are mainly characterized by a reaction zone consisting of a dolomite layer and a symplectitic aggregate of tremolite and dolomite grown between clinohumite and calcite in marble, and a replacement texture of scapolite by clinozoisite in calcsilicate rock. These textures indicate that the retrograde reactions developed under lower temperature (&lt;620°C) and (&lt;0.08–0.16) conditions, assuming a pressure of 0.5 GPa. The metacarbonate rocks share metamorphic temperatures similar to the Mogok paragneiss at the peak granulite facies stage. The values of the metacarbonate rock at peak metamorphic stage are, however, distinctly higher than those previously deduced from carbonate mineral‐free paragneiss. Primary clinohumite, phlogopite and pargasite/edenite in marble have F‐rich compositions, and scapolite in calcsilicate rock contains Cl, suggesting a contrast in the halogen compositions of the metamorphic fluids between these two lithologies. The metamorphic fluid compositions were probably buffered within each lithology, and the effective migration of metamorphic fluid, which would have extensively changed the fluid compositions, did not occur during the prograde granulite facies stage throughout the Mogok metamorphic belt. The lower conditions of the Mogok metacarbonate rocks during the retrograde stage distinctly contrast with higher conditions recorded in metacarbonate rocks from other metamorphic belts of granulite facies. The characteristic low conditions were probably due to far‐ranging infiltration of H2O‐dominant fluid throughout the middle segment of the Mogok metamorphic belt under low‐amphibolite facies conditions during the exhumation and hydration stage.