Observations on the primary phase of milk coagulation by rennet under standardized conditions

1977 ◽  
Vol 44 (2) ◽  
pp. 363-366 ◽  
Author(s):  
Kl. Guthy ◽  
G. Novak
Keyword(s):  
Primary Phase ◽  
Milk Coagulation

Conditions Affecting the Responses of Human Platelets to Epinephrine

1988 ◽  
Vol 60 (02) ◽  
pp. 209-216 ◽  
Author(s):  
Chantal Lalau Keraly ◽  
Raelene L Kinlough-Rathbone ◽  
Marian A Packham ◽  
Hidenori Suzuki ◽  
J Fraser Mustard
Keyword(s):  
Platelet Rich Plasma ◽  
Shape Change ◽  
Human Platelets ◽  
Dense Granule ◽  
Primary Phase ◽  
Lag Phase ◽  
Acid Citrate Dextrose ◽  
Two Phases ◽  
Citrate Dextrose ◽  
Thromboxane Formation

SummaryConditions affecting the responses of human platelets to epinephrine were examined. In platelet-rich plasma prepared from blood anticoagulated with hirudin or PPACK (D-pheny- lalanyl-L-prolyl-L-arginine chloromethyl ketone), epinephrine did not cause shape change or aggregation. In a Tyrode-albumin- apyrase solution containing a concentration of Ca2+ in the physiological range, and fibrinogen, epinephrine in concentrations as high as 40 μM did not induce platelet shape change, caused either no primary aggregation or very slight primary aggregation, and did not induce thromboxane formation, release of dense granule contents, or secondary aggregation. In contrast, in citrated platelet-rich plasma, epinephrine induced two phases of aggregation. This is not attributable to the generation of traces of thrombin since the same effects were evident when blood was taken into a combined citrate-hirudin anticoagulant or a combined citrate-PPACK anticoagulant. In a modified Tyrode-albu- min-apyrase solution containing approximately 20 μM Ca2+, 1 mM Mg2+, and fibrinogen, epinephrine induced extensive aggregation after a lag phase, but no primary phase was evident; thromboxane formation and release of dense granule contents accompanied the aggregation response. These responses were also observed when PPACK was included with the acid-citrate- dextrose anticoagulant, and in the washing and resuspending fluids. In the presence of aspirin or the thromboxane receptor blocker BM 13.177 a few small aggregates were detected by particle counting and by scanning electron microscopy; with the latter inhibitor, the platelets in the aggregates retained their disc shape; secondary aggregation and the responses associated with it did not occur. Thus thromboxane A2 formation is not necessary for the formation of these small aggregates, but is required for extensive aggregation and release. As with other weak agonists, the close platelet-to-platelet contact in the low Ca2+ medium appears to be necessary for full secondary aggregation. Omission of fibrinogen from the low Ca2+ medium prevented both primary and secondary aggregation in response to epinephrine. An antibody (10E5) to the glycoprotein Ilb/IIIa complex was completely inhibitory in the presence of fibrinogen. Thus the response of human platelets to epinephrine is influenced by the concentration of Ca2+ and the presence of fibrinogen in the medium in which they are suspended.

Opposite Effect of Lysine on Platelet Aggregation Induced by Arachidonate and by Other Aggregants

1982 ◽  
Vol 48 (01) ◽  
pp. 078-083 ◽  
Author(s):  
C Ts'ao ◽  
S J Hart ◽  
D V Krajewski ◽  
P G Sorensen
Keyword(s):  
Platelet Aggregation ◽  
Secondary Phase ◽  
Aminocaproic Acid ◽  
Adenosine Diphosphate ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Primary Phase ◽  
High Doses ◽  
The Many ◽  
Induced Aggregation

SummaryEarlier, we found that ε-aminocaproic acid (EACA) inhibited human platelet aggregation induced by adenosine diphosphate (ADP) and collagen, but not aggregation by arachidonic acid (AA). Since EACA is structurally similar to lysine, yet these two agents exhibit vast difference in their antifibrinolytic activities, we chose to study the effect of lysine on platelet aggregation. We used L-lysine-HCl in these studies because of its high solubility in aqueous solutions while causing no change in pH when added to human plasma. With lysine, we repeatedly found inhibition of ADP-, collagen- and ristocetin-induced aggregation, but potentiation of AA-induced aggregation. Both the inhibitory and potentiation effects were dose-dependent. Low doses of lysine inhibited the secondary phase of aggregation; high doses of it also inhibited the primary phase of aggregation. Potentiation of AA-induced aggregation was accompanied by increased release of serotonin and formation of malondialdehyde. These effects were not confined to human platelets; rat platelets were similarly affected. Platelets, exposed to lysine and then washed and resuspended in an artificial medium not containing lysine, remained hypersensitive to AA, but no longer showed decreased aggregation by collagen. Comparing the effects of lysine with equimolar concentrations of sucrose, EACA, and α-amino-n-butyric acid, we attribute the potent inhibitory effect of lysine to either the excess positive charge or H+ and C1− ions. The -NH2 group on the α-carbon on lysine appears to be the determining factor for the potentiation effect; the effect seems to be exerted on the cyclooxygenase level of AA metabolism. Lysine and other chemicals with platelet-affecting properties similar to lysine may be used as a tool for the study of the many aspects of a platelet aggregation reaction.

ВЛИЯНИЕ БИОКОНСЕРВАНТА «СИЛОСТАН» НА КАЧЕСТВО СЕНАЖА ИЗ КОЗЛЯТНИКА ВОСТОЧНОГО И СЫРОПРИГОДНОСТЬ МОЛОКА КОРОВ

2019 ◽  
pp. 51-56
Author(s):  
A.S. KARAMAEVA ◽  
N.V. SOBOLEVA ◽  
S.V. KARAMAEV
Keyword(s):  
Serum Proteins ◽  
Metabolizable Energy ◽  
Holstein Cows ◽  
Technological Properties ◽  
Holstein Breed ◽  
Feed Digestibility ◽  
Ayrshire Breed ◽  
Milk Coagulation ◽  
Dry Substance

От породы коров и ее особенностей зависят эффективность использования кормов, качество и технологические свойства молока. Материалом исследований служили коровы чернопестрой голштинской и айрширской пород. Для повышения качества сенажа из козлятника восточного использовали микробиологический препарат. В готовом корме с биоконсервантом содержание сухого вещества было выше на 3,66, обменной энергии на 8,04, сырого протеина на 10,86, переваримого протеина на 13,59. Улучшение качества корма оказало положительное влияние на метаболические процессы в рубце подопытных коров. Независимо от технологии приготовления сенажа коровы айрширской породы лучше переваривали, по сравнению с голштинами, сухое вещество на 2,062,91 (Р0,05), органическое на 1,212,04 (Р0,05), сырой протеин на 2,222,49 (Р0,05), БЭВ на 0,921,36, но при этом голштины лучше переваривали сырой жир на 2,732,78 (Р0,05) и сырую клетчатку на 1,551,86. В результате внесения в сенаж биоконсерванта Силостан и улучшения переваримости корма у коров опытных групп значительно улучшился химический состав и технологические свойства молока. Очень важно для сыроделия, что в молоке коров, получавших в рационе сенаж с биоконсервантом, повышается массовая доля казеина на 2,42,7, а доля сывороточных белков и фракции казеина, которые не свертываются под действием сычужного фермента, наоборот, снижается на 1,41,5 и на 0,30,9, соответственно. Уменьшается продолжительность свертывания молока сычужным ферментом, снижаются потери сухого вещества с сывороткой, и увеличивается выход казеинового сгустка. Плотность казеинового сгустка повышается в молоке голштинских коров на 14,3, айрширских на 5,7 и составляет, соответственно, 1,92 и 2,96 г/см2.The efficiency of feed use, the quality, as well as technological properties of milk depend on cow breed and its characteristics. Blackandwhite Holstein and Ayrshire breeds were used as the material for research. Microbiological preparation was used to increase the quality of halyage made of Eastern galega. The content of dry substance in the readymade feed was 3.66 higher, the metabolizable energy 8.04 higher, raw protein 10.86 higher, and digestible protein 13.59. Improvement of feed quality positively influenced the metabolic processes in the rumen of experimental cows. Without regard to the technology of halyage preparation, cows of Ayrshire breed showed betterdigestion of dry substance by 2.06 2.91 (P0.05) than Holstein cows, organic substance by 1.21 2.04 (P0.05), raw protein by 2.22 2.49 (P0.05), nitrogenfree extractive fraction by 0.92 1.36, but Holstein breed showed better digestion of raw fat by 2.73 2.78 (P0.05) and raw fiber by 1.55 1.86. Chemical composition and technological properties of milk improved significantly as a result of addition of Silostan biopreservative to the halyage and improvement of feed digestibility in cows from test groups. The fact that the mass percentage of casein is increased by 2.4 2.7, and the share of serum proteins and ycasein fractions which do not coagulate under the influence of enzyme rennet is inversely decreased by 1.4 1.5 and 0.3 0.9, accordingly, is very important for cheese making. The duration of milk coagulation with rennet is decreased, the loss of dry substance with serum is decreased, and the yield of casein coagulate is increased. Density of casein coagulate is increased in the milk of Holstein cows by 14.3, Ayrshire cows by 5.7, and equals to 1.92 and 2.96 g/cm2, accordingly.

Effect of Bi and In on Microstructure Formation in Sn-3Ag-3Bi-3In/Cu and /Ni Solder Joints

2016 ◽  
Vol 700 ◽  
pp. 142-151 ◽  
Author(s):  
Sergey A. Belyakov ◽  
Christopher M. Gourlay
Keyword(s):  
Solid Solution ◽  
Phase Equilibria ◽  
Ternary Compound ◽  
Fine Particles ◽  
Solder Joints ◽  
Primary Phase ◽  
Significant Fraction ◽  
Microstructure Formation ◽  
Five Phases

Sn-3Ag-3Bi-3In solder has been investigated to improve the understanding of microstructure formation in this solder during solidification and soldering to Cu and Ni substrates. The as-solidified microstructures of Sn-3Ag-3Bi-3In samples were found to consist of a significant fraction of βSn dendrites with a complex eutectic between the dendrites. In total five phases were observed to form during solidification: βSn, Ag3Sn, Bi, ζAg and a “Sn-In-Bi” ternary compound. Soldering of Sn-3Ag-3Bi-3In to substrates changed the phase equilibria in the system and caused the formation of additional phases: Cu6Sn5 during soldering to Cu and Ni3Sn4 and metastable NiSn4 during soldering to Ni. It is shown that metastable NiSn4 forms as a primary phase in a complex 5-component Sn-3Ag-3Bi-3In-Ni system. In and Bi were detected in solid solution in the βSn matrix in amounts of ~1.5-2at% and ~1.2at% respectively. Bi also existed as fine particles of two distinct types. (i): sub-micron (<500nm) coral-like particles and (ii) facetted particles measuring up to 7-8 μm.

Effects of full-time v. part-time grazing on seasonal changes in milk coagulation properties and fatty acid composition

2021 ◽  
pp. 1-6
Author(s):  
Franziska S. Akert ◽  
Michael Kreuzer ◽  
Carmen Kunz ◽  
Beat Reidy ◽  
Joel Berard
Keyword(s):  
Fatty Acid ◽  
Seasonal Variations ◽  
Milk Fat ◽  
Seasonal Effects ◽  
Full Time ◽  
Fa Composition ◽  
Part Time ◽  
Milk Coagulation ◽  
The Impact ◽  
Feeding Systems

Abstract For this research communication our objective was to investigate to what extent milk coagulation properties and milk fatty acid (FA) composition were affected by different feeding systems, season and their interaction. Eighteen cows in total were subjected to one of three different feeding system treatments: full-time grazing or part-time grazing combined with indoor feeding of fresh grass with low or high concentrate supplementation. Milk was sampled in spring, summer and autumn. Milk coagulation time was 15.0, 19.0 and 17.7 min, coagulation dynamics 1.67, 3.41 and 1.79 min, and curd firmness 52.7, 32.4 and 47.0 mm in spring, summer and autumn, respectively. Thus, milk coagulation properties of the milk were lower during summer. There were strong seasonal effects on milk FA proportions, but there were not always changes with progressing season, or changes were different with respect to the impact of the feeding systems (system × season interaction). The milk fat was favourably rich in oleic acid, conjugated linoleic acid and α-linolenic acid and had a low n-6/n-3 fatty acid ratio in all systems. Factors like seasonal variations in grass composition and the energy balance of the cows were considered relevant for the milk FA composition. Overall, seasonal variations in milk quality were less pronounced with part-time grazing with fresh grass indoors as compared to full-time grazing without concentrate.

scholarly journals Novel Genes Associated with Dairy Traits in Sarda Sheep

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2207
Author(s):  
Michele Pazzola ◽  
Giuseppe Massimo Vacca ◽  
Pietro Paschino ◽  
Giovanni Bittante ◽  
Maria Luisa Dettori
Keyword(s):  
Association Analysis ◽  
Milk Yield ◽  
Dairy Traits ◽  
Breeding Schemes ◽  
Milk Coagulation ◽  
Set Up ◽  
A Minor ◽  
Daily Milk Yield ◽  
Breed Sheep ◽  
Daily Milk

The aim of the present research was to analyze the variability of 45 SNPs from different genes involved in metabolism and innate immunity to perform an association analysis with the milk yield, composition and milk coagulation traits. A population of 1112 Sarda breed sheep was sampled. Genotyping was generated by a TaqMan Open ArrayTM. Thirty out of the 45 SNPs were polymorphic, and 12 displayed a minor allele frequency higher than 0.05. An association analysis showed that the variability at genes PRKAG3 and CD14 was significantly associated with the daily milk yield. The variability at PRKAG3 was also associated with the protein and casein content, somatic cell score and bacterial score. The variation at the PRKAA2 gene was associated with the milk lactose concentration. The SNPs at CD14 were also associated with the traditional milk coagulation properties, while the SNPs at GHR and GHRHR were associated with kSR, a derived coagulation parameter related to the rate of syneresis. The information provided here is new and increases our knowledge of genotype–phenotype interactions in sheep. Our findings might be useful in appropriate breeding schemes to be set up for the Sarda sheep breed, but these should be confirmed by further studies, possibly performed on independent populations.

Study of milk coagulation induced by chymosin using atomic force microscopy

2019 ◽  
Vol 29 ◽  
pp. 81-85 ◽  
Author(s):  
Cleverson D.T. Freitas ◽  
Maria Z.R. Silva ◽  
João P.B. Oliveira ◽  
Ayrles F.B. Silva ◽  
Márcio V. Ramos ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Milk Coagulation

Stoichiometric and Off-Stoichiometric Alloying in Silicide Compound Ti5Si3 By Nb or Cr Additions

1998 ◽  
Vol 552 ◽  
Author(s):  
Lanting Zhang ◽  
Jiansheng Wu
Keyword(s):  
Total Energy ◽  
Melting Temperature ◽  
Stoichiometric Composition ◽  
Primary Phase ◽  
Titanium Silicide ◽  
Energy Calculation ◽  
Alloying Element ◽  
Total Energy Calculation ◽  
Element Addition ◽  
Cr Addition

ABSTRACTTitanium silicide Ti5Si3 whose melting temperature is 2130°C bears the potential for very hightemperature application. This paper reports our results on the alloying behaviour of Nb or Cr addition to this compound. Total energy calculation shows that the substitution of Ti by Nb or Cr atoms in Ti5Si3 crystal stiffens the bonding between the atoms. In experiment, two means of alloying are considered: stoichiometric and off-stoichiometric alloying. Stoichiometric alloying in Ti5Si3 results in compounds consisting of single Ti5Si3 phase while off-stoichiometric alloying yields hypereutectic microstructure with Ti5Si3 being the primary phase. The Ti5Si3 phase in both cases dissolves certain amount of Nb or Cr alloying element and its composition agrees with the stoichiometric composition of (Ti,Nb) 5Si3 or (Ti,Cr) 5Si3 The moduli of the stoichiometric alloys increase with the increase of alloying element addition, indicating an enhancement in Ti5Si3crystal.

Solidifcation of undercooled melt of Mg-Cu alloy entrapped in its primary phase

1992 ◽  
Vol 11 (18) ◽  
pp. 1260-1262 ◽  
Author(s):  
O. P. Pandey ◽  
S. N. Ojha ◽  
T. R. Anantharaman
Keyword(s):  
Primary Phase ◽  
Cu Alloy ◽  
Undercooled Melt
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