IOP Conference Series: Materials Science and Engineering
In the present work, blood and blood plasma interaction to silver stabilised polyelectrolytes was... more In the present work, blood and blood plasma interaction to silver stabilised polyelectrolytes was investigated in vitro. The designed materials are dedicated for regeneration of the cardiovascular system. Silver nanoparticles were introduced into the polyelectrolyte structure in order to reduce the risk of bacterial biofilm formation. The introduction of Ag nanoparticles occurred by deposition at high vacuum by magnetron sputtering. The analysis of blood-materials interactions were performed by using commercially available tester, Impact-R (Diamed). The assessment of silver ion nanoparticles release into the plasma consisted in determining the Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT). Unmodified surface of polyelectrolytes is a strong activator for blood elements. The introduction of silver nanoparticles resulted in a significant reduction in the probability of clotting. The extrinsic pathway of coagulation determined on the basis of the PT and the intrinsic and common pathways of coagulation measured by the APTT did not indicate the danger out of range. Microstructure was studied using TEM on thin foils prepared from the cross-section of samples subjected to biomedical treatments. The observations revealed hetero-interface between two different crystalline solids.
The paper presents the main achievements of the author on the development of blood contacting mat... more The paper presents the main achievements of the author on the development of blood contacting materials. The main objective of the work is to elaborate materials dedicated for the heart support systems. Appropriately designed biomaterial surfaces enable fully controlled cellular differentiation, proliferation, and even restoration of the tissue structure on solids. The paper presents two approaches to modify the surface, which can control the life processes of tissue. The first solution considers the topography in the form of cell niches. The main objective of the study is a modified surface of thin films deposited on the polymer substrate constituting the microenvironment for the cells caused by residual stress and optimized stiffness of the surface using the plasma methods. The research hypothesis was the plasma surface modification method generating a controlled contribution of residual stress in the coating affect the surface topography in the form of nano- wrinkles similar to t...
Bulletin of the Polish Academy of Sciences Technical Sciences, 2015
The measurement of the strength of bonds between biomaterials and cells is a major challenge in b... more The measurement of the strength of bonds between biomaterials and cells is a major challenge in biotribology since it allows for the identification of different species in adhesion phenomena. Biomaterials, such as diamond-like carbon (DLC), titanium, and titanium nitride, seem to be good candidates for future blood-contact applications. These materials were deposited as thin films by the hybrid pulsed laser deposition (PLD) technique to examine the influence of such surfaces on cell behavior. The biomaterial examinations were performed in static conditions with red blood cells and then subjected to a dynamical test to observe the cell detachment kinetics. The tests revealed differences in behavior with respect to the applied coating material. The strongest cell-biomaterial interaction was observed for the carbon-based materials compared to the titanium and titanium nitride. Among many tests, a radial flow interaction analysis gives the opportunity to analyze cell adhesion to the app...
This paper describes the application of low level controlled torque to an elbow contracture throu... more This paper describes the application of low level controlled torque to an elbow contracture through the use of an active orthosis. Over a period of twenty months the lack of elbow extension range was reduced from 105 degrees to 57 degrees. A description of the important orthotic design factors which led to significant functional improvement is provided.
Presumed or confirmed ornithosis developed in 15 of 46 veterinary surgeons within 3 weeks of thei... more Presumed or confirmed ornithosis developed in 15 of 46 veterinary surgeons within 3 weeks of their attending a training course on the supervision of poultry processing plants. A duck processing plant was the probable source of infection. The attack rate in those visiting this plant was 44% (15/34) and the rate in those who had close contact with duck feathers was 1 7 times the rate in the remainder of the group who visited the plant. The incubation period ranged from 6 to 20 days. This is the second outbreak of duck-associated ornithosis to be recognised in the U.K.
Surface layers, produced on titanium alloys by means of glow discharge nitriding, laser modificat... more Surface layers, produced on titanium alloys by means of glow discharge nitriding, laser modification by remelting using Nd:YAG or diode lasers in nitrogen environment and pulsed laser deposition by titanium target ablation in nitrogen environment, have been studied. Residual stresses were measured using an X-ray method and their values were related to the type of the applied technological process.
ABSTRACT Effects of process parameters on pulsed laser deposition of hydroxyapatite (Ca10(PO4)6(O... more ABSTRACT Effects of process parameters on pulsed laser deposition of hydroxyapatite (Ca10(PO4)6(OH)2) were studied. Process parameters like laser energy and ambient atmosphere influence both the expansion dynamics of a laser ablated plasma plume and topography of deposited layers. The plume created using 193 nm, 20 ns pulses from ArF laser was analysed by means of space and time resolved optical emission spectroscopy. The velocity of the plasma plume at several distances from the target in different ambient conditions was determined. The deposited hydroxyapatite layers were analyzed by means of atomic force microscopy and X-ray diffractometry in order to determine the film topography, its structure and mechanical and physical properties. The results show that the plume expansion velocity as well as the topography of deposited films depend on the sort of ambient gas and its pressure.
A dramatic transition in the mechanical properties of water is observed at the nanometer scale. F... more A dramatic transition in the mechanical properties of water is observed at the nanometer scale. For a water meniscus formed between two hydrophilic surfaces in the attractive region, with 1 nm interfacial separation, the measured viscosity is 7 orders of magnitude greater than that of bulk water at room temperature. Grand canonical Monte Carlo simulations reveal enhancement in the tetrahedral structure and in the number of hydrogen bonds to the surfaces as a source for the high viscosity; this results from a cooperative effect of hydrogen bonding of water molecules to both hydrophilic surfaces.
When rats self-stimulate immediately after the training trial of an appetitive task their perform... more When rats self-stimulate immediately after the training trial of an appetitive task their performance on a retention test is improved the next day. In the present study, this improvement was blocked by pretraining injections of pimozide, a dopaminergic blocker. In a second experiment, injections of pimozide retarded learning on the same task when the learning was reinforced by drinking water, but had no effect on learning which occurred in the absence of a reinforcer. The data made the hypotheses that the animal's behavior was a result of an action of pimozide on sensory or motor mechanisms, or that the drug produced state-dependent effects, highly unlikely. We concluded that neural systems involving dopamine mediate an effect of reinforcing events on behavior.
Multilayers of alternate Cr/CrN coatings deposited on AISI 301 steel by a pulsed Nd:YAG laser hav... more Multilayers of alternate Cr/CrN coatings deposited on AISI 301 steel by a pulsed Nd:YAG laser have been tested by microindentation to measure both hardness and Young's modulus. Critical load LC has been determined by scratch test. The total thickness of multilayers was 1 µm, and the bilayer period Λ varied from between 60 nm and 1000 nm. TEM and EDS techniques were used for investigating and analyzing the microstructure of the multilayers. The results of these measurements show that the mechanical properties of Cr/CrN multilayers depend on the bilayer period. The maximum improvement in performance over a single layer of CrN has been found to be Λ at 250 nm, particularly in terms of critical load and Young's modulus.
An outbreak of ornithosis in duck workers in the winter of 1979 and spring of 1980 was discovered... more An outbreak of ornithosis in duck workers in the winter of 1979 and spring of 1980 was discovered by the investigation of a cluster of cases in Norfolk. A serological survey showed that 61% of duck workers but only 23% of control poultry workers had chlamydia group antibody titres of greater than or equal to 1:8. Altogether 9% of duck workers in the survey had antibody titres greater than or equal to 1:32 and a clinical illness suggestive of ornithosis. The proportions of seropositive tests and clinical attack rates were highest in workers eviscerating ducks and lowest in farm workers. It is suggested that a clinical history of contact with poultry should be considered relevant in the diagnosis of ornithosis and that clinicians caring for poultry workers should consider the possibility of ornithosis as an occupational disease.
... La sienne et celle de ceux qui atten-dront impatiemment son retour. « Étonnants voyageurs ! q... more ... La sienne et celle de ceux qui atten-dront impatiemment son retour. « Étonnants voyageurs ! quelles nobles histoires/ Nous lisons dans vos yeux profonds comme les mers!/ [.. Dites, qu'avez-vous vu?» s'exclame le poète. Et chacun s'empresse de répondre. ...
Intermetallic phases represent a group of materials of unique properties. Many of those materials... more Intermetallic phases represent a group of materials of unique properties. Many of those materials have found practical application, whereas others are still intensively examined. There are ten stable intermetallic phases in Al-Zr system, among which few are prospective materials to work at elevated temperature, nuclear reactors, etc. On top of that, researches are focused on obtaining amorphous phases, nanoparticles and zirconium-based pressure pipes covered with aluminum. As a result, better understanding of thermal effects accompanying those compounds formation becomes crucial. In this paper, solution calorimetry method was used for determination of formation enthalpy D f H of intermetallic phases from Al-Zr system at room temperature (298 K). Experiments were conducted using test station built by author. Material used as bath was aluminum. Additionally, alloys preparation methodology was described and presented. Calorimetric measurements were taken on phases:
The term ’centre of mass’ is to be found in many bioengineering and therapeutic analyses of funct... more The term ’centre of mass’ is to be found in many bioengineering and therapeutic analyses of function and movement of the human body. It is used either with reference to the entire body or to a defined body portion, such as the trunk or the head, arms and trunk. However, this simple concept of centre of mass is problematic when considering the mobility or stability of the complex multisegmented human structure at a particular support point. Disregard for the effects of individual body segments may lead to inappropriate prescription or therapy, particularly in situations where there is deficient control of the relative motion between individual body segments. Reappraisal of the biomechanics of a multisegmented structure
Low-density lipoprotein cholesterol (LDL-C) has a log linear relationship to the risk of coronary... more Low-density lipoprotein cholesterol (LDL-C) has a log linear relationship to the risk of coronary artery disease (CAD) and there is extensive evidence from epidemiological, genetic and animal studies, and from trials of LDL-C modification, demonstrating an important link between LDL-C and CAD LDL-C is the principal target for treatment of conditions associated with insulin resistance and/or the combination of high triglyceride (TG) and/or low high density lipoprotein cholesterol (HDL-C), but non-HDL-C or apolipoprotein B are better therapeutic targets and provide better pre-treatment risk prediction Assessing absolute risk is crucial in ensuring that patients are optimally treated Lifestyle adjustment and targeting of multiple risk factors is necessary to reduce residual risk among those with a high absolute risk of cardiovascular disease Statins are generally safe and well tolerated. Myopathy and rhabdomyolysis are rare at standard doses and usually reverse fully with cessation of therapy
When isosorbide 5-mononitrate was intravenously infused at a rate of 4 mg h-1 for 2.5 h to five h... more When isosorbide 5-mononitrate was intravenously infused at a rate of 4 mg h-1 for 2.5 h to five human subjects, its concentrations in plasma increased slowly to 185 ng ml-1 +/- 5 per cent C.V. at 2.5 h and a steady-state plasma level was not reached during the infusion. When the infusion was discontinued, plasma drug concentrations declined with an elimination half-life of 4.2 h +/- 6 per cent C.V. The systemic clearance after the infusion doses was 132 ml min-1 +/- 18 per cent C.V. and the volume of distribution was 48.4 +/- 16 per cent C.V. After equal oral doses of 10 mg, the peak plasma isosorbide 5-mononitrate concentration of 191 ng ml-1 +/- 16 per cent C.V. was reached at 1.1 h +/- 30 per cent C.V., and plasma levels declined with a terminal half-life of 4.9 h. The complete systemic availability of isosorbide 5-mononitrate indicated that pre-systemic elimination after the oral doses was negligible. A one-compartment open model appeared adequate to describe the plasma level data after intravenous infusion and oral dose. After single oral doses of 10 mg isosorbide dinitrate, the peak plasma concentration of the 5-mononitrate metabolite of 72 ng ml-1 +/- 27 per cent C. V. occurred at 1.7 h +/- 41 per cent C.V. Approximately 50 per cent (range 22--68 per cent) of the oral dose of isosorbide dinitrate circulated in plasma as the 5-mononitrate metabolite. The pharmacokinetics of isosorbide mononitrates are markedly different to those of the parent dinitrate and these differences follow from the greater systemic availability and volume of distribution of the mononitrates.
… Journal of Psychology/Revue canadienne de …, 1978
... memory seems reasonable enough, and many theoretical expressions of this idea have been publi... more ... memory seems reasonable enough, and many theoretical expressions of this idea have been published (eg, Thorndike, 1911; 1933; Estes, 1972; Hebb ... in studies of the ef-fects of brain stimulation on memory (Glickman, 1958; Bloch, 1970, 1976; Kes-ner & Wilburn, 1974; Gold ...
IOP Conference Series: Materials Science and Engineering
In the present work, blood and blood plasma interaction to silver stabilised polyelectrolytes was... more In the present work, blood and blood plasma interaction to silver stabilised polyelectrolytes was investigated in vitro. The designed materials are dedicated for regeneration of the cardiovascular system. Silver nanoparticles were introduced into the polyelectrolyte structure in order to reduce the risk of bacterial biofilm formation. The introduction of Ag nanoparticles occurred by deposition at high vacuum by magnetron sputtering. The analysis of blood-materials interactions were performed by using commercially available tester, Impact-R (Diamed). The assessment of silver ion nanoparticles release into the plasma consisted in determining the Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT). Unmodified surface of polyelectrolytes is a strong activator for blood elements. The introduction of silver nanoparticles resulted in a significant reduction in the probability of clotting. The extrinsic pathway of coagulation determined on the basis of the PT and the intrinsic and common pathways of coagulation measured by the APTT did not indicate the danger out of range. Microstructure was studied using TEM on thin foils prepared from the cross-section of samples subjected to biomedical treatments. The observations revealed hetero-interface between two different crystalline solids.
The paper presents the main achievements of the author on the development of blood contacting mat... more The paper presents the main achievements of the author on the development of blood contacting materials. The main objective of the work is to elaborate materials dedicated for the heart support systems. Appropriately designed biomaterial surfaces enable fully controlled cellular differentiation, proliferation, and even restoration of the tissue structure on solids. The paper presents two approaches to modify the surface, which can control the life processes of tissue. The first solution considers the topography in the form of cell niches. The main objective of the study is a modified surface of thin films deposited on the polymer substrate constituting the microenvironment for the cells caused by residual stress and optimized stiffness of the surface using the plasma methods. The research hypothesis was the plasma surface modification method generating a controlled contribution of residual stress in the coating affect the surface topography in the form of nano- wrinkles similar to t...
Bulletin of the Polish Academy of Sciences Technical Sciences, 2015
The measurement of the strength of bonds between biomaterials and cells is a major challenge in b... more The measurement of the strength of bonds between biomaterials and cells is a major challenge in biotribology since it allows for the identification of different species in adhesion phenomena. Biomaterials, such as diamond-like carbon (DLC), titanium, and titanium nitride, seem to be good candidates for future blood-contact applications. These materials were deposited as thin films by the hybrid pulsed laser deposition (PLD) technique to examine the influence of such surfaces on cell behavior. The biomaterial examinations were performed in static conditions with red blood cells and then subjected to a dynamical test to observe the cell detachment kinetics. The tests revealed differences in behavior with respect to the applied coating material. The strongest cell-biomaterial interaction was observed for the carbon-based materials compared to the titanium and titanium nitride. Among many tests, a radial flow interaction analysis gives the opportunity to analyze cell adhesion to the app...
This paper describes the application of low level controlled torque to an elbow contracture throu... more This paper describes the application of low level controlled torque to an elbow contracture through the use of an active orthosis. Over a period of twenty months the lack of elbow extension range was reduced from 105 degrees to 57 degrees. A description of the important orthotic design factors which led to significant functional improvement is provided.
Presumed or confirmed ornithosis developed in 15 of 46 veterinary surgeons within 3 weeks of thei... more Presumed or confirmed ornithosis developed in 15 of 46 veterinary surgeons within 3 weeks of their attending a training course on the supervision of poultry processing plants. A duck processing plant was the probable source of infection. The attack rate in those visiting this plant was 44% (15/34) and the rate in those who had close contact with duck feathers was 1 7 times the rate in the remainder of the group who visited the plant. The incubation period ranged from 6 to 20 days. This is the second outbreak of duck-associated ornithosis to be recognised in the U.K.
Surface layers, produced on titanium alloys by means of glow discharge nitriding, laser modificat... more Surface layers, produced on titanium alloys by means of glow discharge nitriding, laser modification by remelting using Nd:YAG or diode lasers in nitrogen environment and pulsed laser deposition by titanium target ablation in nitrogen environment, have been studied. Residual stresses were measured using an X-ray method and their values were related to the type of the applied technological process.
ABSTRACT Effects of process parameters on pulsed laser deposition of hydroxyapatite (Ca10(PO4)6(O... more ABSTRACT Effects of process parameters on pulsed laser deposition of hydroxyapatite (Ca10(PO4)6(OH)2) were studied. Process parameters like laser energy and ambient atmosphere influence both the expansion dynamics of a laser ablated plasma plume and topography of deposited layers. The plume created using 193 nm, 20 ns pulses from ArF laser was analysed by means of space and time resolved optical emission spectroscopy. The velocity of the plasma plume at several distances from the target in different ambient conditions was determined. The deposited hydroxyapatite layers were analyzed by means of atomic force microscopy and X-ray diffractometry in order to determine the film topography, its structure and mechanical and physical properties. The results show that the plume expansion velocity as well as the topography of deposited films depend on the sort of ambient gas and its pressure.
A dramatic transition in the mechanical properties of water is observed at the nanometer scale. F... more A dramatic transition in the mechanical properties of water is observed at the nanometer scale. For a water meniscus formed between two hydrophilic surfaces in the attractive region, with 1 nm interfacial separation, the measured viscosity is 7 orders of magnitude greater than that of bulk water at room temperature. Grand canonical Monte Carlo simulations reveal enhancement in the tetrahedral structure and in the number of hydrogen bonds to the surfaces as a source for the high viscosity; this results from a cooperative effect of hydrogen bonding of water molecules to both hydrophilic surfaces.
When rats self-stimulate immediately after the training trial of an appetitive task their perform... more When rats self-stimulate immediately after the training trial of an appetitive task their performance on a retention test is improved the next day. In the present study, this improvement was blocked by pretraining injections of pimozide, a dopaminergic blocker. In a second experiment, injections of pimozide retarded learning on the same task when the learning was reinforced by drinking water, but had no effect on learning which occurred in the absence of a reinforcer. The data made the hypotheses that the animal's behavior was a result of an action of pimozide on sensory or motor mechanisms, or that the drug produced state-dependent effects, highly unlikely. We concluded that neural systems involving dopamine mediate an effect of reinforcing events on behavior.
Multilayers of alternate Cr/CrN coatings deposited on AISI 301 steel by a pulsed Nd:YAG laser hav... more Multilayers of alternate Cr/CrN coatings deposited on AISI 301 steel by a pulsed Nd:YAG laser have been tested by microindentation to measure both hardness and Young's modulus. Critical load LC has been determined by scratch test. The total thickness of multilayers was 1 µm, and the bilayer period Λ varied from between 60 nm and 1000 nm. TEM and EDS techniques were used for investigating and analyzing the microstructure of the multilayers. The results of these measurements show that the mechanical properties of Cr/CrN multilayers depend on the bilayer period. The maximum improvement in performance over a single layer of CrN has been found to be Λ at 250 nm, particularly in terms of critical load and Young's modulus.
An outbreak of ornithosis in duck workers in the winter of 1979 and spring of 1980 was discovered... more An outbreak of ornithosis in duck workers in the winter of 1979 and spring of 1980 was discovered by the investigation of a cluster of cases in Norfolk. A serological survey showed that 61% of duck workers but only 23% of control poultry workers had chlamydia group antibody titres of greater than or equal to 1:8. Altogether 9% of duck workers in the survey had antibody titres greater than or equal to 1:32 and a clinical illness suggestive of ornithosis. The proportions of seropositive tests and clinical attack rates were highest in workers eviscerating ducks and lowest in farm workers. It is suggested that a clinical history of contact with poultry should be considered relevant in the diagnosis of ornithosis and that clinicians caring for poultry workers should consider the possibility of ornithosis as an occupational disease.
... La sienne et celle de ceux qui atten-dront impatiemment son retour. « Étonnants voyageurs ! q... more ... La sienne et celle de ceux qui atten-dront impatiemment son retour. « Étonnants voyageurs ! quelles nobles histoires/ Nous lisons dans vos yeux profonds comme les mers!/ [.. Dites, qu'avez-vous vu?» s'exclame le poète. Et chacun s'empresse de répondre. ...
Intermetallic phases represent a group of materials of unique properties. Many of those materials... more Intermetallic phases represent a group of materials of unique properties. Many of those materials have found practical application, whereas others are still intensively examined. There are ten stable intermetallic phases in Al-Zr system, among which few are prospective materials to work at elevated temperature, nuclear reactors, etc. On top of that, researches are focused on obtaining amorphous phases, nanoparticles and zirconium-based pressure pipes covered with aluminum. As a result, better understanding of thermal effects accompanying those compounds formation becomes crucial. In this paper, solution calorimetry method was used for determination of formation enthalpy D f H of intermetallic phases from Al-Zr system at room temperature (298 K). Experiments were conducted using test station built by author. Material used as bath was aluminum. Additionally, alloys preparation methodology was described and presented. Calorimetric measurements were taken on phases:
The term ’centre of mass’ is to be found in many bioengineering and therapeutic analyses of funct... more The term ’centre of mass’ is to be found in many bioengineering and therapeutic analyses of function and movement of the human body. It is used either with reference to the entire body or to a defined body portion, such as the trunk or the head, arms and trunk. However, this simple concept of centre of mass is problematic when considering the mobility or stability of the complex multisegmented human structure at a particular support point. Disregard for the effects of individual body segments may lead to inappropriate prescription or therapy, particularly in situations where there is deficient control of the relative motion between individual body segments. Reappraisal of the biomechanics of a multisegmented structure
Low-density lipoprotein cholesterol (LDL-C) has a log linear relationship to the risk of coronary... more Low-density lipoprotein cholesterol (LDL-C) has a log linear relationship to the risk of coronary artery disease (CAD) and there is extensive evidence from epidemiological, genetic and animal studies, and from trials of LDL-C modification, demonstrating an important link between LDL-C and CAD LDL-C is the principal target for treatment of conditions associated with insulin resistance and/or the combination of high triglyceride (TG) and/or low high density lipoprotein cholesterol (HDL-C), but non-HDL-C or apolipoprotein B are better therapeutic targets and provide better pre-treatment risk prediction Assessing absolute risk is crucial in ensuring that patients are optimally treated Lifestyle adjustment and targeting of multiple risk factors is necessary to reduce residual risk among those with a high absolute risk of cardiovascular disease Statins are generally safe and well tolerated. Myopathy and rhabdomyolysis are rare at standard doses and usually reverse fully with cessation of therapy
When isosorbide 5-mononitrate was intravenously infused at a rate of 4 mg h-1 for 2.5 h to five h... more When isosorbide 5-mononitrate was intravenously infused at a rate of 4 mg h-1 for 2.5 h to five human subjects, its concentrations in plasma increased slowly to 185 ng ml-1 +/- 5 per cent C.V. at 2.5 h and a steady-state plasma level was not reached during the infusion. When the infusion was discontinued, plasma drug concentrations declined with an elimination half-life of 4.2 h +/- 6 per cent C.V. The systemic clearance after the infusion doses was 132 ml min-1 +/- 18 per cent C.V. and the volume of distribution was 48.4 +/- 16 per cent C.V. After equal oral doses of 10 mg, the peak plasma isosorbide 5-mononitrate concentration of 191 ng ml-1 +/- 16 per cent C.V. was reached at 1.1 h +/- 30 per cent C.V., and plasma levels declined with a terminal half-life of 4.9 h. The complete systemic availability of isosorbide 5-mononitrate indicated that pre-systemic elimination after the oral doses was negligible. A one-compartment open model appeared adequate to describe the plasma level data after intravenous infusion and oral dose. After single oral doses of 10 mg isosorbide dinitrate, the peak plasma concentration of the 5-mononitrate metabolite of 72 ng ml-1 +/- 27 per cent C. V. occurred at 1.7 h +/- 41 per cent C.V. Approximately 50 per cent (range 22--68 per cent) of the oral dose of isosorbide dinitrate circulated in plasma as the 5-mononitrate metabolite. The pharmacokinetics of isosorbide mononitrates are markedly different to those of the parent dinitrate and these differences follow from the greater systemic availability and volume of distribution of the mononitrates.
… Journal of Psychology/Revue canadienne de …, 1978
... memory seems reasonable enough, and many theoretical expressions of this idea have been publi... more ... memory seems reasonable enough, and many theoretical expressions of this idea have been published (eg, Thorndike, 1911; 1933; Estes, 1972; Hebb ... in studies of the ef-fects of brain stimulation on memory (Glickman, 1958; Bloch, 1970, 1976; Kes-ner & Wilburn, 1974; Gold ...
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