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1.
J Phys Chem A ; 123(1): 343-358, 2019 Jan 10.
Article in English | MEDLINE | ID: mdl-30540469

ABSTRACT

In order to define a robust level of theory using density functionals for investigating the reactivity of ruthenium complexes, we used benchmark wave function theory, with saturated basis sets to validate generalized gradient approximation (GGA), meta-GGA, and hyper-GGA functionals in the presence and absence of empirical dispersion and range-separated corrections. We first selected potentially suitable functionals that gave accurate predictions of the relative energetics of coordination isomers. These functionals were further evaluated for the chemical accuracy of their predicted geometric and electronic structures. For the latter, both the ionic and covalent interactions were considered. The reference level of theory for comparison was coupled-cluster perturbation theory using full treatment of singles and doubles (CCSD) with a saturated triple-ζ quality basis set (TZVP) and corresponding small-core, effective core potentials for ruthenium. Several population analysis methods were evaluated to predict the ionic interactions. We found that the atomic charges obtained from fitting the electrostatic potential provided the most reasonable estimates for the ruthenium complexes. The covalent interactions were quantified by considering the atomic compositions of Ru 4d x2- y2- and 4d z2-based frontier unoccupied orbitals. Comparison of more than two dozen functionals with reference data from high-level wave function calculations revealed trends that allowed for the formulation of an optimal hybrid density functional: PBE exchange and correlation functionals with 50% HF exchange component. This level of theory was found to reproduce the experimental structure of Ru(II) complexes. These complexes were used to investigate chemical speciation in a simplified model for an ionic liquid environment.

2.
Caries Res ; 53(3): 305-313, 2019.
Article in English | MEDLINE | ID: mdl-30359980

ABSTRACT

The aim of this study was to evaluate the anti-erosive effect of solutions containing sodium fluoride (F: 225 ppm F-), stannous chloride (Sn: 800 ppm Sn2+), and some film-forming polymers (Gantrez: Poly [methylvinylether-alt-maleic anhydride]; PGA: propylene glycol alginate; Plasdone: poly[vinylpyrrolidone]; and CMC: carboxymethylcellulose). Solutions were tested in an erosion-remineralization cycling model, using enamel and dentin specimens (n = 10, for each substrate). Distilled water was the negative control. Cycling consisted of 120 min immersion in human saliva, 5 min in 0.3% citric acid solution, and 120 min of exposure to human saliva, 4×/day, for 5 days. Treatment with solutions (pH = 4.5) was carried out 2×/day, for 2 min. Surface loss (SL) was evaluated with optical profilometry. Zeta potential of hydroxyapatite crystals was determined after treatment with the solutions. Data were statistically analyzed (α = 0.05). For enamel, all polymers showed significantly lower SL (in µm) than the control (11.09 ± 0.94), except PGA (10.15 ± 1.25). PGA significantly improved the protective effect of F (4.24 ± 0.97 vs. 5.64 ± 1.60, respectively). None of the polymers increased the protection of F+Sn (5.13 ± 0.78). For dentin, only Gantrez (11.40 ± 0.97) significantly reduced SL when compared with the negative control (12.76 ± 0.75). No polymer was able to enhance the effect of F (6.28 ± 1.90) or F+Sn (7.21 ± 1.13). All fluoridated solutions demonstrated significantly lower SL values than the control for both substrates. Treatment of hydroxyapatite nanoparticles with all solutions resulted in more negative zeta potentials than those of the control, except Plasdone, PGA, and F+Sn+PGA, the latter two presenting the opposite effect. In conclusion, Gantrez, Plasdone, and CMC exhibited an anti-erosive effect on enamel. PGA increased the protection of F. For dentin, only Gantrez reduced erosion.


Subject(s)
Sodium Fluoride/chemistry , Tin Compounds/chemistry , Tooth Erosion/prevention & control , Alginates , Carboxymethylcellulose Sodium , Humans , In Vitro Techniques , Maleates , Polymers , Polyvinyls , Povidone , Tin Fluorides
3.
Chem Soc Rev ; 46(15): 4645-4660, 2017 Jul 31.
Article in English | MEDLINE | ID: mdl-28644493

ABSTRACT

It is widely accepted within the community that to achieve a sustainable society with an energy mix primarily based on solar energy we need an efficient strategy to convert and store sunlight into chemical fuels. A photoelectrochemical (PEC) device would therefore play a key role in offering the possibility of carbon-neutral solar fuel production through artificial photosynthesis. The past five years have seen a surge in the development of promising semiconductor materials. In addition, low-cost earth-abundant co-catalysts are ubiquitous in their employment in water splitting cells due to the sluggish kinetics of the oxygen evolution reaction (OER). This review commences with a fundamental understanding of semiconductor properties and charge transfer processes in a PEC device. We then describe various configurations of PEC devices, including single light-absorber cells and multi light-absorber devices (PEC, PV-PEC and PV/electrolyser tandem cell). Recent progress on both photoelectrode materials (light absorbers) and electrocatalysts is summarized, and important factors which dominate photoelectrode performance, including light absorption, charge separation and transport, surface chemical reaction rate and the stability of the photoanode, are discussed. Controlling semiconductor properties is the primary concern in developing materials for solar water splitting. Accordingly, strategies to address the challenges for materials development in this area, such as the adoption of smart architectures, innovative device configuration design, co-catalyst loading, and surface protection layer deposition, are outlined throughout the text, to deliver a highly efficient and stable PEC device for water splitting.

4.
Chem Soc Rev ; 44(21): 7808-28, 2015 Nov 07.
Article in English | MEDLINE | ID: mdl-26204436

ABSTRACT

Photocatalysis is a promising technology that can contribute to renewable energy production from water and water purification. In order to further develop the field and meet industrial requirements, it is imperative to focus on advancing high efficiency visible light photocatalysts, such as silver phosphate (Ag3PO4). This review aims to highlight the recent progress made in the field, focusing on oxygen production from water, and organic contaminant decomposition using Ag3PO4. The most important advances are discussed and explained in detail, including semiconductor-semiconductor junctions, metal-semiconductor junctions, exposing facet control, and fundamental understanding using advanced spectroscopies and computational chemistry. The review then concludes by critically summarising both findings and current perspectives, and ultimately how the field might best advance in the near future.

5.
J Am Chem Soc ; 136(36): 12568-71, 2014 Sep 10.
Article in English | MEDLINE | ID: mdl-25136991

ABSTRACT

For the first time, it is demonstrated that the robust organic semiconductor g-C3N4 can be integrated into a nature-inspired water splitting system, analogous to PSII and PSI in natural photosynthesis. Two parallel systems have been developed for overall water splitting under visible light involving graphitic carbon nitride with two different metal oxides, BiVO4 and WO3. Consequently, both hydrogen and oxygen can be evolved in an ideal ratio of 2:1, and evolution rates in both systems have been found to be dependent on pH, redox mediator concentration, and mass ratio between the two photocatalysts, leading to a stable and reproducible H2 and O2 evolution rate at 36 and 18 µmol h(-1) g(-1) from water over 14 h. Our findings demonstrate g-C3N4 can serve as a multifunctional robust photocatalyst, which could also be used in other systems such as PEC cells or coupled solar cell systems.

6.
Chemistry ; 20(40): 12954-61, 2014 Sep 26.
Article in English | MEDLINE | ID: mdl-25156820

ABSTRACT

ZnO has long been considered as a model UV-driven photoanode for photoelectrochemical water splitting, but its performance has been limited by fast charge-carrier recombination, extremely poor stability in aqueous solution, and slow kinetics of water oxidation. These issues were addressed by applying a strategy of optimization and passivation of hydrothermally grown 1D ZnO nanowire arrays. The length and diameter of bare ZnO nanowires were optimized by varying the growth time and precursor concentration to achieve optimal photoelectrochemical performance. The addition of earth-abundant cobalt phosphate (Co-Pi) and nickel borate (Ni-B) oxygen evolution catalysts onto ZnO nanowires resulted in substantial cathodic shifts in onset potential to as low as about 0.3 V versus the reversible hydrogen electrode (RHE) for Ni-B/ZnO, for which a maximum photocurrent density of 1.1 mA cm(-2) at 0.9 V (vs. RHE) with applied bias photon-to-current efficiency of 0.4 % and an unprecedented near-unity incident photon-to-current efficiency at 370 nm. In addition the potential required for saturated photocurrent was dramatically reduced from 1.6 to 0.9 V versus RHE. Furthermore, the stability of these ZnO nanowires was significantly enhanced by using Ni-B compared to Co-Pi due to its superior chemical robustness, and it thus has additional functionality as a stable protecting layer on the ZnO surface. These remarkable enhancements in both photocatalytic activity and stability directly address the current severe limitations in the use of ZnO-based photoelectrodes for water-splitting applications, and can be applied to other photoanodes for efficient solar-driven fuel synthesis.

7.
Chemistry ; 20(47): 15571-9, 2014 Nov 17.
Article in English | MEDLINE | ID: mdl-25280047

ABSTRACT

Photocatalysis provides a cost effective method for both renewable energy synthesis and environmental purification. Photocatalytic activity is dominated by the material design strategy and synthesis methods. Here, for the first time, we report very mild and effective photo-deposition procedures for the synthesis of novel Fe2 O3 -TiO2 nanocomposites. Their photocatalytic activities have been found to be dramatically enhanced for both contaminant decomposition and photoelectrochemical water splitting. When used to decompose a model contaminant herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), monitored by both UV/Vis and total organic carbon (TOC) analysis, 10% Fe-TiO2 -H2 O displayed a remarkable enhancement of more than 200 % in the kinetics of complete mineralisation in comparison to the commercial material P25 TiO2 photocatalyst. Furthermore, the photocurrent is nearly double that of P25. The mechanism for this improvement in activity was determined using density functional theory (DFT) and photoluminescence. These approaches ultimately reveal that the photoelectron transfer is from TiO2 to Fe2 O3 . This favours O2 reduction which is the rate-determining step in photocatalytic environmental purification. This in situ charge separation also allows for facile migration of holes from the valence band of TiO2 to the surface for the expected oxidation reactions, leading to higher photocurrent and better photocatalytic activity.

8.
Sci Rep ; 14(1): 17044, 2024 07 24.
Article in English | MEDLINE | ID: mdl-39048642

ABSTRACT

American white (Quercus alba L.) oak casks have been used for liquid storage for centuries. Their use in aged spirits is critical to imparting flavor and mouthfeel to the final product. The reason that barrels retain liquid has been hypothesized to be the result of abundant physiological structures called tyloses in parenchyma tissues and medullary rays in white oak. Using non-destructive X-ray computed tomography (XRCT) imaging, we reveal an unprecedented view of tylose structure and quantify the pore-filling capacity of tyloses in white oak that underscores the liquid retention we observe in casks. We show that pores of white oaks are filled with sevenfold higher tylose volume compared to northern red oak (Q. rubra), consistent with prior literature that casks made from white oak retain liquid while red oak fails to do so. We propose that XRCT represents a methodological standard for observing these complex structures and should be employed to understand the many questions related to liquid losses from casks, cultural treatment of casks, and the influence of climate change on oak tyloses in the future.


Subject(s)
Quercus , Tomography, X-Ray Computed , Tomography, X-Ray Computed/methods , Wine/analysis , Imaging, Three-Dimensional/methods
9.
J Hosp Infect ; 122: 173-179, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35124141

ABSTRACT

BACKGROUND: An unprecedented rise in the number of COVID-19-associated mucormycosis (CAM) cases has been reported in India. Myriad hypotheses are proposed for the outbreak. We recently reported uncontrolled diabetes and inappropriate steroid therapy as significant risk factors for the outbreak. However, Mucorales contamination of hospital environment was not studied. AIM: To perform a multi-centre study across India to determine possible Mucorales contamination of hospital environment during the outbreak. METHODS: Eleven hospitals from four zones of India representing high to low incidence for mucormycosis cases were included in the study. Samples from a variety of equipment used by the patients and ambient air were collected during May 19th, 2021 through August 25th, 2021. FINDINGS: None of the hospital equipment sampled was contaminated with Mucorales. However, Mucorales were isolated from 11.1% air-conditioning vents and 1.7% of patients' used masks. Other fungi were isolated from 18% of hospital equipment and surfaces, and 8.1% of used masks. Mucorales grew from 21.7% indoor and 53.8% outdoor air samples. Spore counts of Mucorales in air were significantly higher in the hospitals of North and South zones compared to West and East zones (P < 0.0001). Among Mucorales isolated from the environment, Rhizopus spp. were the most frequent genus. CONCLUSION: Contamination of air-conditioning vents and hospital air by Mucorales was found. Presence of Mucorales in these areas demands regular surveillance and improvement of hospital environment, as contamination may contribute to healthcare-associated mucormycosis outbreaks, especially among immunocompromised patients.


Subject(s)
COVID-19 , Mucorales , Mucormycosis , Disease Outbreaks , Hospitals , Humans , India/epidemiology , Mucormycosis/epidemiology
10.
J Mycol Med ; 21(1): 33-6, 2011 Mar.
Article in English | MEDLINE | ID: mdl-24451501

ABSTRACT

We describe the third fatal case of imported coccidioidomycosis in India in a 31-year-old mechanical engineer originally from Andhra Pradesh, India, who lived in Gwinner, North Dakota. He had traveled to Arizona in summer of 2006, where he drove tractors in a dusty environment at a tractor production facility near Phoenix, Arizona. He was human immunodeficiency virus (HIV) positive. Initially, he was treated in Fargo, North Dakota, in 2006, with liposomal amphotericin B followed by oral fluconazole. Antiretroviral treatment for HIV infection was started. He moved back to India and was admitted to the intensive care unit of St. John's Medical College and Hospital, Bangalore, India. His blood cultures yielded Coccidioides sp. The identity of the isolate was confirmed using the Gen Probe Accuprobe test at the Centers for Disease Control and Prevention, Atlanta, Georgia. In spite of initiation of treatment with antifungal agents (amphotericin B and fluconazole), his condition deteriorated and he expired three days following his admission to the hospital.

11.
ACS Appl Mater Interfaces ; 13(24): 28600-28609, 2021 Jun 23.
Article in English | MEDLINE | ID: mdl-34110762

ABSTRACT

Mass production of defect-free single-layer graphene flakes (SLGFs) by a cost-effective approach is still very challenging. Here, we report such single-layer graphene flakes (SLGFs) (>90%) prepared by a nondestructive, energy-efficient, and easy up-scalable physical approach. These high-quality graphene flakes are attributed to a novel 10 s microwave-modulated solid-state approach, which not only fast exfoliates graphite in air but also self-heals the surface of graphite to remove the impurities. The fabricated high-quality graphene films (∼200 nm) exhibit a sheet resistance of ∼280 Ω/sq without any chemical or physical post-treatment. Furthermore, graphene-incorporated Ni-Fe electrodes represent a remarkable ∼140 mA/cm2 current for the catalytic water oxidation reaction compared with the pristine Ni-Fe electrode (∼10 mA/cm2) and a 120 mV cathodic shift in onset potential under identical experimental conditions, together with a faradic efficiency of >90% for an ideal ratio of H2 and O2 production from water. All these excellent performances are attributed to extremely high conductivity of the defect-free graphene flakes.

12.
J Biophotonics ; 14(9): e202100090, 2021 09.
Article in English | MEDLINE | ID: mdl-34105881

ABSTRACT

This clinical study tested cross-polarization optical coherence tomography (CP-OCT) monitoring of erosive tooth wear (ETW). Twenty participants completed a 14-day/arm, 3-arm crossover study simulating different ETW severities. Participants received two enamel specimens (per arm) and were randomized to: severe (s-ETW, lemon juice/pH:2.5/4.25%wt/vol citric acid), moderate (m-ETW, grapefruit juice/pH:3.5/1.03%wt/vol citric acid), and non-ETW (water). Enamel thickness was measured with CP-OCT (day[D] 0, 7, 14) and micro-computed tomography (µ-CT; D14). Enamel surface loss was determined with CP-OCT and optical profilometry (OP; D7, D14). CP-OCT showed higher enamel surface loss for D14 than D7 for m-ETW (P = .009) and s-ETW (P = .040) and differentiated severity at D14 (s-ETW > non-ETW, P = .027). OP was able to differentiate surface loss between days (D7 < D14, P < .001) for m-ETW and s-ETW, and ETW severity effect after 7 and 14 days (non-ETW < m-ETW < s-ETW, P < .001). At D14, CP-OCT and µ-CT were positively correlated (r = .87, ICC = .62). CP-OCT showed potential as a tool for clinical ETW monitoring.


Subject(s)
Tooth Erosion , Tooth Wear , Cross-Over Studies , Humans , Tomography, Optical Coherence , Tooth Erosion/diagnostic imaging , X-Ray Microtomography
13.
Clin Microbiol Infect ; 26(7): 944.e9-944.e15, 2020 Jul.
Article in English | MEDLINE | ID: mdl-31811914

ABSTRACT

OBJECTIVES: To describe the epidemiology, management and outcome of individuals with mucormycosis; and to evaluate the risk factors associated with mortality. METHODS: We conducted a prospective observational study involving consecutive individuals with proven mucormycosis across 12 centres from India. The demographic profile, microbiology, predisposing factors, management and 90-day mortality were recorded; risk factors for mortality were analysed. RESULTS: We included 465 patients. Rhino-orbital mucormycosis was the most common (315/465, 67.7%) presentation followed by pulmonary (62/465, 13.3%), cutaneous (49/465, 10.5%), and others. The predisposing factors included diabetes mellitus (342/465, 73.5%), malignancy (42/465, 9.0%), transplant (36/465, 7.7%), and others. Rhizopus species (231/290, 79.7%) were the most common followed by Apophysomyces variabilis (23/290, 7.9%), and several rare Mucorales. Surgical treatment was performed in 62.2% (289/465) of the participants. Amphotericin B was the primary therapy in 81.9% (381/465), and posaconazole was used as combination therapy in 53 (11.4%) individuals. Antifungal therapy was inappropriate in 7.6% (30/394) of the individuals. The 90-day mortality rate was 52% (242/465). On multivariate analysis, disseminated and rhino-orbital (with cerebral extension) mucormycosis, shorter duration of symptoms, shorter duration of antifungal therapy, and treatment with amphotericin B deoxycholate (versus liposomal) were independent risk factors of mortality. A combined medical and surgical management was associated with a better survival. CONCLUSIONS: Diabetes mellitus was the dominant predisposing factor in all forms of mucormycosis. Combined surgical and medical management was associated with better outcomes. Several gaps surfaced in the management of mucormycosis. The rarer Mucorales identified in the study warrant further evaluation.


Subject(s)
Antifungal Agents/therapeutic use , Fungi/classification , Mucormycosis/epidemiology , Adult , Combined Modality Therapy , Disease Management , Female , Humans , India/epidemiology , Lung Diseases, Fungal/epidemiology , Lung Diseases, Fungal/mortality , Male , Middle Aged , Mucormycosis/classification , Mucormycosis/mortality , Mucormycosis/therapy , Prospective Studies , Risk Factors , Skin Diseases/epidemiology , Skin Diseases/microbiology , Survival Analysis , Treatment Outcome
14.
ACS Omega ; 4(1): 1449-1459, 2019 Jan 31.
Article in English | MEDLINE | ID: mdl-31459412

ABSTRACT

A simplistic and low-cost method that dramatically improves the performance of solution-grown hematite photoanodes for solar-driven water splitting through incorporation of nanohybrid metal oxide overlayers was developed. By heating the α-Fe2O3/SnO2-TiO2 electrode in an inert atmosphere, such as argon or nitrogen, the photocurrent increased to over 2 mA/cm2 at 1.23 V versus a reversible hydrogen electrode, which is 10 times higher than that of pure hematite under 1 sun (100 mW/cm2, AM 1.5G) light illumination. For the first time, we found a significant morphological difference between argon and nitrogen gas heat-treated hematite films and discussed the consequences for photoresponse. The origin for the enhancement, probed via theoretical modeling, stems from the facile incorporation of low formation energy dopants into the Fe2O3 layer at the interface of the metal oxide nanohybrid overlayer, which decreases recombination by increasing the electrical conductivity of Fe2O3. These dopants diffuse from the overlayer into the α-Fe2O3 layer readily under inert gas heat treatment. This simple yet effective strategy could be applied to other dopants to increase hematite performance for solar energy conversion applications.

15.
Chem Commun (Camb) ; 53(55): 7748-7751, 2017 Jul 06.
Article in English | MEDLINE | ID: mdl-28650013

ABSTRACT

For the first time, a one-step scalable synthesis of a few-layer ∼10% nitrogen doped (N-doped) graphene nanosheets (GNSs) from a stable but highly reactive 1,3-dipolar organic precursor is reported. The utilization of these N-doped GNSs as metal-free electrocatalysts for the oxygen evolution reaction (OER) is also demonstrated. This process may open the path for the scalable production of other heteroatom doped GNSs by using the broad library of well-known, stable 1,3-dipolar organic compounds.

16.
Chem Sci ; 7(8): 4832-4841, 2016 Aug 01.
Article in English | MEDLINE | ID: mdl-30155131

ABSTRACT

We report the synthesis and photoelectrochemical assessment of phase pure tetragonal matlockite structured BiOX (where X = Cl, Br, I) films. The materials were deposited using aerosol-assisted chemical vapour deposition. The measured optical bandgaps of the oxyhalides, supported by density functional theory calculations, showed a red shift with the increasing size of halide following the binding energy of the anion p-orbitals that form the valence band. Stability and photoelectrochemical studies carried out without a sacrificial electron donor showed the n-type BiOBr film to have the highest photocurrent reported for BiOBr in the literature to date (0.3 mA cm-2 at 1.23 V vs. RHE), indicating it is an excellent candidate for solar fuel production with a very low onset potential of 0.2 V vs. RHE. The high performance was attributed to the preferred growth of the film in the [011] direction, as shown by X-ray diffraction, leading to internal electric fields that minimize charge carrier recombination.

17.
Nanoscale ; 7(39): 16343-53, 2015 Oct 21.
Article in English | MEDLINE | ID: mdl-26383028

ABSTRACT

Phase-pure BiFeO3 films were grown directly via dual-source low-pressure CVD (LPCVD) from the ligand-matched precursors [Bi(O(t)Bu)3] and [Fe(O(t)Bu)3]2, without the requirement for oxidising gas or post deposition annealing. Photocatalytic testing for water oxidation revealed extremely high activity for PEC water splitting and photocatalytic water oxidation under visible light irradiation (λ > 420 nm) with a benchmark IPCE for BiFeO3 of 23% at 400 nm. The high activity is ascribed to the ultrafine morphology achieved via the LPCVD process. The performance was enhanced by over four times when the BiFeO3 photoanode is coupled to a Ni-B surface OEC.


Subject(s)
Calcium Compounds/chemistry , Light , Nickel/chemistry , Oxides/chemistry , Oxygen/chemistry , Photochemical Processes , Titanium/chemistry , Water/chemistry , Catalysis
18.
Bone ; 7(3): 187-91, 1986.
Article in English | MEDLINE | ID: mdl-3768196

ABSTRACT

In a case of CPPD crystal deposition disease of the pseudorheumatoid type and of long duration, calcified constrictive pericarditis developed and was surgically treated. Analysis of the calcium deposit in the pericardium was carefully made by infrared absorption, x-ray diffraction, and thermogravimetry. It revealed that the deposit was composed of B-type carbonated apatite. Previously, both calcium pyrophosphate dihydrate (CPPD) and apatite crystals, either in the same place or in different tissues, have been reported in the same patient. These observations raise the possibility that the same metabolic error might lead to both types of crystal deposition.


Subject(s)
Calcinosis/metabolism , Calcium/analysis , Chondrocalcinosis/complications , Pericarditis, Constrictive/metabolism , Apatites/analysis , Calcinosis/complications , Calcium Pyrophosphate/analysis , Crystallography , Female , Humans , Middle Aged , Pericarditis, Constrictive/complications
19.
Domest Anim Endocrinol ; 12(1): 73-82, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7542581

ABSTRACT

Effects of recombinant bovine somatotropin (rbST) on ovarian and uterine function and the production of components of the insulin-like growth factor (IGF) system were examined during the period of maternal recognition of pregnancy in cattle. Lactating dairy cows were treated with 25 mg/d rbST (n = 8) or saline (n = 8) for 16 d after estrus. Ovaries, uteri, and conceptuses were collected on Day 17 after estrus. The length (millimeters) of the conceptus was recorded. The concentration of IGF-I and the content of IGF-binding proteins (BP) in uterine flushings were determined. Corpora lutea (CL) were weighed, and the number of follicles (> or = 2 mm in diameter) were counted. Follicular fluid from the largest and second-largest follicles was assayed for the concentration of IGF-I, IGFBP, progesterone, and estradiol. The length of the conceptus and the total amount of IGF-I in uterine fluid were similar for rbST and control. Recombinant bST increased 1) the weight of the CL, 2) the number of largest follicles (10 to 15 mm in diameter), 3) the concentration of IGF-I in the follicular fluid, 4) the follicular fluid content of IGFBP of the largest estrogenic follicle, and 5) the quantity of IGFBP in uterine flushings. The concentration of progesterone in the follicular fluid tended to be increased in rbST-treated cows, whereas the concentration of estradiol was similar to that of control cows. The concentration of progesterone in plasma was similar for rbST compared with control. In conclusion, the administration of rbST in lactating dairy cows for 16 d after estrus did not alter the growth of the conceptus collected on Day 17. The greatest responses to rbST were found within the ovary, where rbST increased the weight of the CL and altered the amount of IGF-I and IGFBP in the follicular fluid.


Subject(s)
Cattle/physiology , Fetus/drug effects , Growth Hormone/pharmacology , Ovary/drug effects , Pregnancy, Animal/physiology , Uterus/drug effects , Animals , Carrier Proteins/analysis , Carrier Proteins/blood , Cattle/metabolism , Corpus Luteum/chemistry , Corpus Luteum/drug effects , Corpus Luteum/physiology , Estradiol/analysis , Estradiol/blood , Female , Fetus/physiology , Follicular Fluid/chemistry , Follicular Fluid/metabolism , Insulin-Like Growth Factor Binding Proteins , Insulin-Like Growth Factor I/analysis , Lactation/physiology , Ovarian Follicle/cytology , Ovarian Follicle/drug effects , Ovarian Follicle/metabolism , Ovary/chemistry , Ovary/physiology , Pregnancy , Progesterone/analysis , Progesterone/blood , Recombinant Proteins/pharmacology , Uterus/chemistry , Uterus/physiology
20.
Theriogenology ; 42(1): 183-203, 1994.
Article in English | MEDLINE | ID: mdl-16727525

ABSTRACT

Postpartum ovarian activity, uterine involution and plasma concentrations of calcium and 15-keto-13, 14 dihydro-prostaglandin F2alpha (PGFM) were assessed in dairy cows with retained fetal membranes (n=10) and milk fever (n=10) at parturition. In addition, calcium and PGFM were evaluated in dairy cows affected with uterine prolapse (n=10) and pyometra (n=14). Cows with retained fetal membrane averaged 24.2+/-3.7 d until their first postpartum ovulation, while controls averaged 29.0+/-3.7 d (P>0.10). In cows with retained fetal membranes, the difference in follicular activity between the contralateral and ipsilateral ovaries in relation to the previously gravid uterine horn was appreciably greater post partum when compared with that of the controls. Cows with milk fever had an average of 30.8+/-3.1 d until their first postpartum ovulation, while control cows had an average of 20.4+/-3.3 d (P<0.05). The mean diameter of the uterine horns in cows with milk fever was greater (P<0.05) compared with that of the controls between Days 15-32 post partum. Concentrations of plasma calcium were lower in cows with retained fetal membranes within 24 h after parturition and during the first week post partum than in the controls (6.27+/-0.18 vs 7.40+/-0.18 mg/100ml, P<0.05). Concentration of calcium was lower (P<0.05) in cows with milk fever on Day 1 prior to treatment (4.68+/-0.40 < 5.8+/-0.45 mg/100ml) than in control cows; however, the calcium (Ca) level was not different during the subsequent 7 d post partum after treatment. Cows with uterine prolapse had lower concentrations of Ca during the first 7 d post partum than the controls (6.10+/-0.15 vs 7.33+/-0.12mg/100ml; P<0.01). Cows with pyometra had higher (P<0.05) concentrations of plasma PGFM than the controls (208.+/-13.2 > 138.1+/-15.2).

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