bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis and application of energy absorption characteristics of expansion tube type absorber
Authors: Yin Hang , Zhang Xiaolong , Zhang Yu
Published: July 2018

Passive safety protection technology is to reduce the damage caused by collision by improving the anti-impact performance of the system itself. It has important engineering practical value. Many scholars have carried out the research on the collision design of the train in the structure design of the track vehicle. The core is to absorb the kinetic energy of the collision by absorbing energy structure to reduce the force generated during the collision and minimize casualties. The expansion tube type absorber is usually used as a collision safety protection device in the track vehicle. The quasi-static compression test is carried out for the expansion tube type absorber. The energy absorption characteristics and compression characteristics of the expansion tube energy absorber in quasi-static compression test are studied experimentally. The design and research of the energy absorber for rail vehicles are of guiding significance and practical value.
Investigation on Behavior of Castellated Composite Beams under Fire
Authors: Wang Yuhan , Jia Lianguang , Li Xuefeng
Published: July 2018

This paper is to study the fire resistance of castellated composite beams. Based on experiment, a reasonable castellated composite beam model is established by using finite element software. The critical temperature of castellated composite beams influenced by hole opening ratio, hole pitch, width-thickness ratio of the web and stiffener have been analyzed. The result shows that stiffener has a great influence on the fire resistance of castellated composite beams, which can increase the critical temperature greatly. The width-thickness ratio of the web has some influence on the buckling behavior of castellated composite beams under fire condition. When width-thickness ratio is higher, the web is more prone to buckling failure. The hole opening ratio and hole pitch have a little influence on the fire resistance of castellated composite beams.
Research on three dimensional detection system of fatigue cracks of steel box girder
Authors: Lin Su , Jian Zhang , Xi Cheng
Published: July 2018

The fatigue cracks are inevitably existed in steel bridges after they are working for a fairly short time because of the environmental pollution, overloading vehicles and larger numbers of automobiles. How to efficiently detect the fatigue cracks, especially the initial fatigue cracks, become one of the most important question to be solved for the steel box girder. The static and fatigue tests of the orthotropic steel bridge deck models were carried out in this research paper, which presented the fatigue damage developing laws, compared the test results with homogeneous test results in existing documents. Three dimensional micro detection scheme of fatigue cracks in steel box girder with three dimensional detection system is studied. Through the data from the testing design, the important characteristic width and length of the fatigue crack can be achieved, which can be used for the grasping of the mechanism of the steel box girder.
Study on the theory of three-dimensional limit analysis of soil and practical calculation
Authors: Lia Bin , Fu Jianbao
Published: July 2018

Based on the stress analysis of a point in space, the stress analysis of a point on a surface is performed, and then the relationship among the normal stress, the shear stress, and the stress component of a point on a surface and the first order partial derivative of the surface equation is deduced. Equilibrium equations of soil columns between the sliding surface and the top surface of the slope are established, which include differential equilibrium equation of force, equilibrium equation of force, and equilibrium equation of moment. These equilibrium equations and Coulomb yield condition can form the fundamental equations of three-dimensional slope stability analysis. Applying the supposition similar to that applied in the simplified Bishop method, a kind of three-dimensional slope analysis method can be obtained. An example is presented to show that the computation method is reasonable and applicable.
Gateway Electric Energy Meter Measurement System Based on Independent Load Control
Authors: Sike Wang , Yu Guo , Jun Li , Tian Xia , Ming Lei
Published: July 2018

In order to meet the efficiency and timeliness measurement requirements for electric energy meters with different specifications in gateway energy meter testing laboratory, a new testing system based on multithreading technique is proposed here. Through identifying the different wiring modes of electric meters, integrating with newly designed CT based on zero-flux compensation principle and applying creative multi-channel load control for different tap positions, the system can provide differentiated testing loads for different meters at the same time. Meanwhile, electric energy pulses required by different electric energy meters can be worked out by one standard meter. Consequently, completely independent measurement for different meters will be achieved with improved timeliness substantially. Through simulation tests for different electric energy meters, and comparison for calculated testing time, the initial design purposes are tested and verified.
Research on Launch Dynamics Modeling and Simulating for Surface-to-air Missile Supported by Adapter
Authors: Chaoqi Liu , LiHua Wen , Jiangjun He , Yuxiang Liu
Published: July 2018

The launch dynamics analysis model of surface-to-air missile supported by the adapter was established, and the model was verified by test data. Simulation analysis shows: the missile begins to generate pitch angular speed at semi-constrained state after mid-adapter leave the tube, and the speed increases with distance between the mid-adapter and the rear adapter, and as the thrust of the engine increases to decreases, as the launch angle decreases, the missile's pitch angular speed increases, gravity is the main cause of the launch disturbance in the direction of the pitching.
Dynamic Analysis of Planetary Gear Train Based on ADAMS
Authors: Yuan Yongliang
Published: July 2018

Automatic pin machine is a kind of typical equipment widely used in mechanical and electronic industry, which is mainly used for automatic assembly of pinhole parts. In order to improve the efficiency and stability of the transmission system, the dynamic performance of planetary gears is studied. This paper uses UG to establish the dynamic model of planetary gears. Dynamic simulation and its motion law are obtained using Adams. The contact force between the planet gear and the center gear fluctuates around 5000N, and increases with the load. The results show that Adams can provide an effective prediction of the dynamic characteristics of planetary gear trains, and have a certain reference value for future structural improvements.
Heuristic Algorithm for Type II Two-sided Assembly Line Rebalancing Problem with Multi-objective
Authors: Zhang Yahui , Hu Xiaofeng , Wu Chuanxun
Published: July 2018

In practical production, the balance of the assembly lines is always destroyed by many factors, e.g., demand fluctuations, disruptions caused by workstation breakdowns or shutdowns, and changes of the work force. Therefore, this paper addresses the type II rebalancing problem for the two-sided assembly lines (TALRBP-II), which are widely utilized to assemble large-size high-volume products. As we all know that TALBP-II (two-sided assembly line balancing problem type-II) is NP-hard, TALRBP-II is its extension and much more complex. In order to solve this problem, a mathematical model with the objectives of minimizing cycle time and rebalancing cost is proposed. Constraint programming (CP) method is applied to optimize the model and a workstation-oriented heuristic algorithm is designed to solve the problem. An example is presented to illustrate the procedure of the proposed algorithm, and the best solution obtained verify the efficiency of the proposed algorithm.
Research on widening construction clearance on the transition curve of existing railway lines based on SIMPACK
Authors: Chen Li , Yu Liu , Chao Chen
Published: July 2018

This paper selects appropriate vehicle as the standard vehicle and designs its shape. Secondly, it chooses some control point on the vehicle according to the current standard. Thirdly, the essay sets four difficult operating conditions with different curve radius and superelevation, simulates on the SIMPACK software and compares the value of control points offset the centre of railway line to the current construction clearance. According to the result of comparison, this paper divides transition curve into three parts to widen construction clearance and proposes the definition of correction coefficient. At last, the paper compares construction clearance that has been corrected with existing construction clearance to check whether the new one is right or not. The study shows that if curve part is divided into three parts to widen construction clearance, it would be more reasonable and satisfactory.
Energy savings achieved from recommissioning a research and development center
Authors: Huang Xinjiang , Liu Chenggang , Miao Yuyang
Published: July 2018

The recommissioning is performed for a research and development (R&D) center located in Suzhou. The hardware problems of Heating, Ventilation and Air Conditioning (HVAC) system and software problems of Electrical Monitoring and Control System (EMCS) were found. The recommissioning measures were generated and control logic in EMCS was optimized and improved. The saving of about 121kW for chilled water consumption, 181kW for hot water consumption and 1450 kWh/D for electricity consumption from recommissioning were achieved from recommissioning measures.
Analysis of agricultural information service needs in the suburbs of Beijing
Authors: Zheng Yaming , Luo Changshou , Cao Chengzhong , Wei Qingfeng , Yu Jun
Published: July 2018

A questionnaire survey was carried out on the theme of the demand for agricultural information service in the suburbs of Beijing. On the basis of the investigation, the demand of agricultural information service in the suburb of Beijing was analyzed, and the suggestions on the agricultural information service were put forward in combination with the actual situation.
Ecological optimization design of silage equipment key components based on innovation method theory
Authors: Wang Jianqiang , Lv Bing , Yan Jie , Li Yingjun , Li Zequn , Chen Mengjia
Published: July 2018

Ecological environmental issues are constantly threatening the survival and development of human society and has been concerned by all walks of life. The seven ecological efficiency factors proposed by the WBCSD are the basis for improving the ecological performance. Through the mapping relationship between ecological efficiency factors and 39 engineering parameters, the ecological issues will be transferred to engineering problems. It is guided by the corresponding design concepts. Furtherly the TRIZ problem solving tools will be applied. Thereby, the optimized solution will be obtained. It can not only effectively reduce the environmental impact of products, but also can shorten the development cycle of green products while satisfying functional requirements. The development of China’s agricultural machinery is extensive. This method is used to implement ecological optimization design of the bundling device mounting frame for silage equipment, which has important guiding significance for the development of China's agricultural machinery.
Design and Implementation of HD Video Encoding System Based on HDMI
Authors: Gao Wanjia , Sun Baohai , Peng Qingqing , Zhang Huixin
Published: July 2018

Focus on the problem that TI’s dedicated video processor TMS320DM8148 cannot directly collect video data from HDMI interface, this paper presents a video coding system based on H.264.The system used DSP+FPGA architecture, FPGA is responsible for collecting video data of HDMI interface and caching. And then send to DM8148 through GPMC, DM8148 completes video encoding and decoding through the interaction of internal modules. The results show that video is displayed clearly and smoothly, without distortion or error. It successfully realizes the collection of the video data of HDMI interface obtained with DM8148.
Image recognition of individual cow based on SIFT in Lαβ color space
Authors: Lv Feng , ZHANG Chunmei , Lv Changwei
Published: July 2018

Using image recognition technology to identify individual dairy cattle with her biological features shows strong stability. This kind of non-contact, high precision and low cost individual recognition methods based on image processing are more and more popular recently to replace the electronic tag and ear mark which can hurt the cattle’s psychology and physical health and can affect cattle’s behavior. By comparing the various color space transformations, he proposed a scale-invariant feature transform algorithm based on the Luminace of Lαβ color space. With this algorithm, a biological features recognition and management system of Holstein cow has been developed. The identification accuracy is higher than 98%, which is the best result than all the similar reports for cows’ identification.
The Application of Traditional Culture in Industrial Design in New Epoch
Authors: Shuang Wu
Published: July 2018

This paper is based on industrial design, collation and analysis the Chinese traditional culture to expound the essentiality in design. From the perspective of design aesthetics to discuss the Chinese traditional cultural characteristics express under the background of the new era with artistic language, to provide new design ideas for industrial design with Chinese characteristics in the new era.
Reinterpreting Form Bionic Design and its Application in Design Innovation with Multiple Methods
Authors: Yang Qiao
Published: July 2018

This paper expounds the background and market demands of the application of Form Bionic Design (FBD) in design innovation. Then it analyses the advantages of FBD and existing misunderstandings on its definition and application, leading to the topic on how to correctly understand the classification of Bionic Design. Also it clarifies the significance of the integration of Bionic Design, proposing that FBD should follow the requirements of users and Design Hardpoints (DHPs). Then through a series of design cases it introduces the application of FBD compromised with several special methods, which includes Userexperiencing in simulation, Modular Design for system optimization and Keywords on style positioning. Meanwhile it respectively discusses the purpose, the function and particular application of each method, providing practical reference for its particular combination with FBD.
Teaching Research on the manual Model of Product Design
Authors: Ying Liu , Xiaojing Liu , Yi Chen
Published: July 2018

This paper discribes the spatial thinking ability, materials processing, design easthetics application and technical implementation are four aspects that very important to cultivate students– professional quality when building a manual model. It stresses the handwork l model course has played positive significance in the aspect of design basic teaching under the background of High-Tech.
Web-based Agricultural Technology Evaluation Information System: Design, Application and Evaluation
Authors: Ren Yanzhao , Wang Minjuan , Gao Wanlin , Hu Hui , Chen Xuerui
Published: July 2018

This study describes the web-based agricultural technology evaluation information system, which has been shown to provide a flexible interface with which to arrange various assessment and information management function procedures. Secondly, this study examines the effects of the application of the academic misconduct detection mechanism and abnormally scoring mechanism. In an evaluative study with the two evaluation business cycle of the system, it has been found that this system is more efficient, more accurate and more rigorous than the traditional offline evaluation model. It has also been shown that cheating behaviour in agricultural technological achievements information declaration and evaluation link can be detected accurately and promptly.
Research on Form Design of New Generation Upgrade Products Based on Brand Identity
Authors: Su JN , Lv Y , Wang P , Bai RS
Published: July 2018

The form design of new generation upgrade products based on the brand identity was studied in this paper, and the regional cultural symbols was integrated into it creatively, which provided a new way of thinking for the design of new generation upgrade products. Taking the AC contactor of Tianshui 213 as an example, firstly the consumer ' s perceptual demand and the brand identity of the products was analyzed, secondly kansei engineering theory was used to deconstruct the form of products, and then design format analysis was used to deconstruct the regional cultural symbols. Finally, the relevant design elements were combined to create a new product with regional culture and era characteristics.
FBS framework application based on user requirement analysis
Authors: Qing ZHANG , Deng-kai CHEN
Published: July 2018

Users’ requirements are key factor for optimizing the design of products. It could be classified into two groups: qualitative research work and quantitative research work. Wireless internet terminal equipment could be used as one example to further study the qualitative research work of requirements. FBS guided by users’ requirements was discussed. The users centered service designing process model was established through the analysis of users’ needs (Ra) in the function of design, use-pattern, delivery and transformation. Based on this work, the relation between users’ needs and requirements of the design was set up. The completely research work about transformation of users’ needs to design requirements was discussed in this study, and finally a wireless terminal equipment was used as a case study to verify this method.
Preparation and Properties of 5-Fluorouracil-Loaded Chitosan Microspheres for the Intranasal Administration
Authors: Li Wanqing , Ba Hongyuan , Huang Peng , Zheng Aiping , Yang Xi
Published: July 2018

Objective To study the preparation technique of 5-fluorouracil and the release characteristic of 5-fluorouracil-loaded chitosan microspheres for the intranasal administration.

Methods 5-fluorouracil-loaded chitosan microspheres were prepared by emulsion chemical cross-link technique. The orthogonal experimental design was used to optimize the preparation procedure. Dynamic dialysis method was applied to determine the release characteristic of microspheres in vitro and its influencing factors. Swelling behavior was expressed by swelling ratio. The degree of mucoadhesion was investigated by determining the mucociliary transport rate(MTR) of the microparticle across a frog palate.

Results Microspheres with a good shape and narrow size distribution were prepared. The average diameter was 43±4 μm. The drug loading was (38.5±1.0) %. The entrapment efficiency was (79.0±1.8) %. The drug release profile in vitro could be described by Higuichi eqution as Q=0.1035t1/2+0.0284 (r=0.9965). Chitosan had good mucoadhesive property and caused a significant reduction in MTR(P<0.01).

Conclusion The optimized technique has a good reproducibility and a high entrapment efficiency, so it could be used to prepare 5-fluorouracil-loaded chitosan microspheres for the intranasal administration.Chitosan is a good material for nasal preparation and has prospective development in the pharmaceutical field.
Rehabilitation in Germany 2004–2016 A Multicenter Analysis Over a Period of 13 Years in Children and Adolescents with Diabetes Mellitus
Authors: Schiel Ralf , Stachow Rainer , Hermann Thomas , Satzke Ina , Büttner Thomas , Koch Sibylle , Enderlein Katja , Bambauer Rolf , Steveling Antje , Bollow Esther , Holl Reinhard W. ,   for the DPVWiss Initiative
Published: July 2018

In the treatment of children/adolescents with diabetes medical rehabilitation plays an important role. It was the aim of the survey to analyze trends in the number of patients admitted to rehabilitation, the quality of diabetes care, the incidence of acute complications, risk factors for cardiovascular co-morbidities like lipids and blood pressure and the familial status nationwide and over a period of 13 years. Methods: Currently seven hospitals offer in-patient rehabilitation for children/adolescents with diabetes in Germany. Six hospitals participated in the survey. All children/adolescents (n=7.163) who participated in an in-patient rehabilitation 01/01/2004-31/12/2016 were included. Clinical/familial data were assessed: age, sex, family situation, type/duration of diabetes, insulin dosage, self-monitoring, acute complications, height, body weight, blood pressure and laboratory parameters. For collecting and storage of data the computer software DPV® (Diabetes-Patienten-Verlaufsdokumentation, University of Ulm, Germany) was used. Statistical analyses were performed using the programme SAS (Statistical Analysis Software 9.4, SAS Institute Inc, Cary, North Carolina, USA). Results: During the study period 7.163 patients took part in 10.987 in-patient rehabilitation procedures. The yearly number of patients participating in rehabilitation remained stable. There was no change in the quality of diabetes control (HbA1c: p=0.30, fasting blood glucose: p=0.80). The incidence of severe hypoglycaemia decreased (p<0.001). The incidence of ketacidosis remained stable (p=0.18). The frequency of blood glucose self-monitoring increased (p<0.001). The same was true for patients treated with CSII (p<0.001), whereas the numbers of patients treated with CT or ICT decreased (both p<0.001). There was no change in patients’ total insulin dose (p=0.01). There was a decrease of the number of patients living with both parents (p<0.001), the percentage of children/adolescents living with mother or father alone increased (p<0.001). The percentage of children/adolescents living in mixed cultural families or having a background of immigration increased (p<0.001). Conclusions: There is a change in medical rehabilitation: The number is stable, the proportion of patients using CSII increased, the number of patients living with single parents and the percentage of patients from culturally mixed families increased also.
Ein Erfahrungsbericht
Authors: Schwarz Sarah
Published: July 2018

Als Reaktion auf die deutlich zunehmende Unterernährung im Distrikt von Bokoro, Tschad, eröffnete die Organisation „Ärzte ohne Grenzen“ vor Ort im Frühjahr 2014 ein Nothilfeprogramm zur Behandlung unterernährter Kinder. In dieses Projekt führte die Autorin (angehende Kinderärztin) ihr erster Hilfseinsatz. Für insgesamt 6 Monate arbeitete sie in einem Team aus internationalen und tschadischen Mitarbeitern. Die Patienten wurden je nach Schweregrad der Erkrankung entweder ambulant in mobilen Kliniken oder stationär in einer eigens dafür aufgebauten Krankenstation behandelt. Dabei stand neben einer systematischen Ernährungstherapie mit hochkalorischer Erdnusspaste (PPN, plumpy nut) oder therapeutischer Milchnahrung nur eine eingeschränkte Auswahl an Medikamenten zur Verfügung. Malaria und andere Infektionskrankheiten wie Gastroenteritis und Pneumonie stellten den Großteil der Erkrankungen dar, wobei die körperliche Untersuchung meist zur Diagnosestellung ausreichen musste. Der klinische Blick war hier das wichtigste Werkzeug.
Thrombin Generation in Newborn Plasma Is Critically Dependent on the Concentration of Prothrombin
Authors: Andrew Maureen , Schmidt Barbara , Mitchell Lesley , Paes Bosco , Ofosu Frederick
Published: July 2018

The ability to generate thrombin is decreased and delayed in plasma from the healthy newborn infant compared to the adult. Only 30 to 50% of peak adult thrombin activity can be produced in neonatal plasma. To test whether this observation can be explained by the low neonatal levels of the contact or vitamin K dependent factors, we measured neonatal thrombin generation after raising the concentration of these factors to adult values. We also determined whether the addition of a variety of blood products to neonatal plasma improved thrombin generation. An amidolytic method was used to quantitate intrinsic (APTT) and extrinsic (PT) pathway thrombin generation in defibrinated pooled cord plasma from healthy term infants. Added individually, factors VII, IX, X or the contact factors (CF) failed to alter the rate or the total amount of thrombin generated in neonatal plasma. In contrast, the addition of prothrombin increased the total amount of thrombin generated to above adult values in both the APTT and the PT systems but did not alter the rate of thrombin generation. The rate of thrombin generation in cord plasma shortened after a combination of II, IX, X and CF was added to the APTT system or II, VII and X to the PT system. In both systems, the total amount of thrombin generated was linearly related to the initial prothrombin concentration. Each of fresh frozen plasma, cryoprecipitate, plasma from platelet concentrates, or factor IX concentrate (in amounts used therapeutically) caused an increase in the total amount of thrombin generated which was related to the increase in prothrombin concentration. Thus, the total amount of thrombin generated in newborn plasma is critically dependent on the prothrombin concentration whereas the rate at which thrombin is generated is dependent on the levels of many other coagulation proteins in combination.
Effect of Protein C and Activated Protein C on Coagulation and Fibrinolysis in Normal Human Subjects
Authors: Okajima Kenji , Koga Shin , Kaji Megumi , Inoue Masayasu , Nakagaki Tomohiro , Funatsu Akinobu , Okabe Hiroaki , Takatsuki Kiyoshi , Aoki Nobuo
Published: July 2018

Although protein C (PC) and activated protein C (APC) have been postulated to be useful for treating patients with thrombosis, their critical effect remains to be studied in human subjects. To examine whether purified PC or APC are useful for treating patients with thrombosis without showing any adverse effect, wc studied effects on coagulation and fibrinolysis in normal human subjects.

When highly purified human PC was administered intravenously to healthy subjects, plasma levels of immunoreactive PC decreased with a half-life of 10.9 h. Intravenously administered APC decreased with a half-life of 23 min as measured by prolongation of activated partial thromboplastin time (APTT). However, 1.7 h was obtained for the plasma half-life of APC when it was measured immunologically. These findings suggested that a significant fraction of the administered APC was rapidly inhibited by plasma inhibitor. Upon administration of APC, APTT was prolonged and plasma levels of clotting factor VIII (FVIII) decreased transiently as measured by clotting assay. However, when determined by a chromogenic assay method in which 120-fold diluted plasma samples were used, plasma levels of FVIII remained unchanged. Plasma levels of F-V did not decrease after APC administration. These findings suggested that prolongation of APTT and apparent decrease in plasma F-VIII clotting activity might be due to the in vitro-effect of APC present in plasma samples used. Diurnal fluctuation of plasminogen activator inhibitor in normal subjects was not affected by administration of APC.

Thus, PC or APC seems to function selectively at the site of thrombin-formation without lowering plasma levels of coagulation factors.
Quantification of Functional and Inactivated α2-Macroglobulin in Sepsis
Authors: Abbink J J , Nuijens J H , Eerenberg A J M , Huijbregts C C M , Strack van Schijndel R J M , Thijs L G , Hack C E
Published: July 2018

Alpha2-macroglobulin (α2M) in vitro inhibits numerous proteinases that are generated during inflarnmatory reactions and therefore, probably plays an important role in diseases such as sepsis. To monitor the state of α2M in sepsis, we developed novel assays for functional and inactive α2M. Functional α2M in palsama trypsin. Inactive α2M (iα2M) was assessed with a monoclonal antibody, mcAb M1, that specifically reacts with a neodeterminant exposed on iα2M. This mcAb in combination with chromogenic substrates was used to detect α2M-proteinase complexes.

Functional α2M was reduced in plasma from 48 patients with clinical sepsis compared to healthy controls (p <0.0001). Levels of functional α2M on admission and the lowest levels encountered in 23 patients with shock were lower than in 25 normotensive patienis (p = 0.023 and p = 0.009, respectively). Increased levels of iα2M (>30 nM) at least on one occasion were found in only 4 of the 48 patients, being not different in hypotensive compared With normotensive patients, and not in patients who died compared with those who survived. Levels of functional α2M correlated significantly with levels of factor XII and prekallikrein suggesting that decreases in α2M at least in part were due to contact activation. Indeed, in two patients with increased iα2M, complexes between α2M and kallikrein were demonstrated in addition to plasmin- and thrombin-α2M complexes.
Ticlopidine and Clopidogrel (SR 25990C) Selectively Neutralize ADP Inhibition of PGE1-Activated Platelet Adenylate Cyclase in Rats and Rabbits
Authors: Defreyn G , Gachet C , Savi P , Driot F , Cazenave J P , Maffrand J P
Published: July 2018

Ticlopidine and its potent analogue, clopidogrel, are powerful inhibitors of ADP-induced platelet aggregation. In order to improve the understanding of this ADP-selectivity, we studied the effect of these compounds on PGE1-stimulated adenylate cyclase and on the inhibition of this enzyme by ADP, epinephrine and thrombin. Neither drug changed the basal cAMP levels nor the kinetics of cAMP accumulation upon PGEj-stimulation in rat or rabbit platelets, which excludes any direct effect on adenylate cyclase or on cyclic nucleotide phosphodiesterase. However, the drop in cAMP levels observed after addition of ADP to PGEr stimulated control platelets was inhibited in platelets from treated animals. In contrast, the drop in cAMP levels produced by epinephrine was not prevented by either drug in rabbit platelets. In rat platelets, thrombin inhibited the PGEX-induced cAMP elevation but this effect seems to be entirely mediated by the released ADP. Under these conditions, it was not surprising to find that clopidogrel also potently inhibited that effect of thrombin on platelet adenylate cyclase. In conclusion, ticlopidine and clopidogrel selectively neutralize the ADP inhibition of PGEr activated platelet adenylate cyclase in rats and rabbits.
Subcutaneous Heparin Therapy during Pregnancy: a Need for Concern at the Time of Delivery
Authors: Anderson David R , Ginsberg Jeffrey S , Burrows Robert , Brill-Edwards Pat
Published: July 2018

Subcutaneous heparin is the treatment of choice for women requiring anticoagulant therapy during pregnancy. However, heparin therapy presents a management problem at delivery because of its potential to cause a persistent anticoagulant effect and thus increase the risk of bleeding. In order to avoid therapeutic complications it has been our practice to have women eithei discontinue their heparin injections with the onset of labour or to terminate heparin injections 12 h prior to elective induction. To determine the safety of our anticoagulant protocol at delivery we reviewed consecutive patients treated with subcutaneous heparin therapy during pregnarcl, at our centre. Over a 23 month period we found that six of 11 women receiving subcutaneous heparin during pregnancy delivered while their aPTT was prolonged. In addition, three women received intravenous protamine sulphate prior to delivery and in one patient major bleeding occurred during an emergency cesarean section. Those women who had elevated aPTTs at the time of delivery all gave birth within 28 h of their last injection of heparin. In order to avoid a prolonged aPTT at delivery, we have now adopted a more conservative approach to the management of subcutaneous heparin use at term. Subcutaneous heparin is discontinued 24 h prior to commencing an elective induction of labour.
The British System for Anticoagulant Control
Authors: Poller L
Published: July 2018

The British system for anticoagulant control based on the use of a national reagent with a national system of reporting supported by national quality control using lyophilized plasma preparations appears to offer a model which many countries abroad seem interested in adopting to solve their own national problems. Good progress has already been made in this direction in some Commonwealth countries and in South Africa. At a symposium at the 3rd Mediterranean Congress on Thromboembolism in 1973 invited participants from all over the world agreed to set up an International Study Group to provide an international organisation for anticoagulant control, and an encouraging start has been made.
Assay of Brinase Inhibitors with Soluble and Insoluble Substrates
Authors: Nyman D , Duckert F
Published: July 2018

Two methods for the assay of brinase inhibitors are compared. Neither provided a reliable means of brinase dose prediction. Overdosage can, however, be avoided by preinfusion inhibitor assay.
The Effect of Fatty-acid Autoxidation Products on Blood Coagulation
Authors: Barrowcliffe T. W , Guttteridge J. M. C , Dormandy T. L
Published: July 2018

Polyunsaturated fatty acids were allowed to autoxidise in air over 4 days. The water soluble oxidation products were extracted at daily intervals and tested for their effect on blood coagulation. After 1 day there was slight acceleration of the recalcification and RVV times, but from 2–4 days the extracts became increasingly inhibitory. The P.T. and P.T.T. were also inhibited. In the thrombin generation test the extracts delayed the appearance of thrombin, but the peak thrombin level was increased and its rate of decay was reduced. When added to phospholipid the extracts altered their coagulant activity. The presence of autoxidation products could account for some of the variable results obtained with different preparations of phospholipids.
Plasmin Inhibition of Thrombin-induced Platelet Aggregation
Authors: Miller Jonathan L , Katz Alfred J , Feinstein Maurice B
Published: July 2018

The effects of plasmin treatment upon washed human platelets were studied in an attempt to elucidate the mechanisms underlying thrombin-induced platelet aggregation. At calcium concentrations of 10–20 μM, plasmin (0.2 CTA U/ml) inhibited thrombin-induced aggregation almost completely, but did not diminish the thrombin-induced release of adenine nucleotides, 5-hydroxytryptamine, or calcium. Increasing the calcium concentration partially antagonized plasmin’s inhibition of aggregation.

Studies utilizing calcium chelators and the Kunitz soybean trypsin inhibitor (SBTI) as a plasmin inhibitor indicated that in order to achieve maximal block of aggregation, plasmin must act upon a substrate made fully available only after an initial thrombin-platelet interaction has taken place. Moreover, the time course of this inhibition parallels the time course of the thrombin-induced release reaction.

Plasmin inhibition of aggregation could not be mimicked by exposing the platelets to proteolytic digests of fibrinogen at concentrations as high as 17% total platelet protein. Nor could inhibitory activity be recovered from supernatants of plasmin -treated platelets, upon centrifugation and treatment with SBTI.

With the use of a “cold initiation” technique, the release by thrombin of 46.7 ± 6-7 (mean ± SEM) μg of fibrinogen immunological equivalents per mg platelet protein could be demonstrated. Platelets in which thrombin-induced aggregation was abolished by plasmin treatment (and the plasmin subsequently inactivated by SBTI) aggregated normally upon addition of as little as 10 μg human plasma fibrinogen per mg platelet protein.

It is concluded that plasmin inhibition of aggregation most likely results from its attack upon a protein that is released or becomes fully available subsequent to interaction of thrombin with a platelet receptor mediating release. The results of this study are consistent with a cofactor role for fibrinogen in the aggregation of human platelets by thrombin.
Characterization of the Fawn-Hooded Rat as a Model for Hemostatic Studies
Authors: Raymond Sharon L , Jean Dodds W
Published: July 2018

A large colony of fawn-hooded (FH) rats, comprising five original families and six generations of their progeny, was developed for genetic and comparative studies of their bleeding tendency. The characteristics of the bleeding diathesis in these rats are similar to those originally reported in related rats by Tschopp and Zucker. FH rats have normal clot retraction, ADP-induced platelet aggregation and platelet ADP ; variable aggregation with collagen; minimal aggregation with adrenaline and cobra venom factor; and reduced platelet ATP, ATP/ADP ratio, serotonin content and 14C-serotonin release. In comparison to age- and sex-matched Wistar rats, FH rats have significantly prolonged partial thromboplastin time, shortened Russell’s viper venom time and increased factor X and XI levels. Other coagulation screening tests and specific assays for fibrinogen, plasminogen and factors VII, VIII and IX were normal. Some age- and sex-related differences in coagulation and other parameters were observed within each rat strain. Plasma proteins, glycoproteins and cerulo-plasmin (copper oxidase activity) showed no abnormalities, nor did initial studies of immunoglobulins and complement. However, FH rats have significantly lower glucose and higher cholesterol levels than comparable Wistar rats.
Changes in Human Amniotic Fluid Fibrinolytic Inhibitor Levels during Pregnancy
Authors: Aznar J , Hernandez A , Parrilla J.J , Estelles A , Gilabert J
Published: July 2018

The amniotic fluid (AF) when incubated with the patient’s own plasma diminishes the lytic activity of the plasma. It is suggested that this inhibition is due to the presence of fibrinolytic inhibitors in the AF. The inhibitors rate increases as pregnancy advances. Evaluating these inhibitors in a group of 65 women before and after the 38th week of pregnancy, a higher rate of fibrinolytic inhibitors is found after the 38th week. The said differences are statistically significant. For the moment it does not seem that the increasing of the inhibitors in the last part of pregnancy might be used as a fetal maturity test.
In Vitro and in Vivo Functions of Thrombin-Treated Platelets
Authors: Reimers Hans-Joachim , Kinlough-Rathbone Raelene L. , Cazenave Jean-Pierre , Senyi Andrew F. , Hirsh Jack , Packham Marian A. , Mustard J. Fraser
Published: July 2018

Thrombin-induced platelet aggregation has been generally believed to be irreversible. However, thrombin-induced aggregation of washed platelets is reversible if fibrin formation is prevented or the fibrin which binds the platelets together is removed from the platelet aggregates. After treatment with high concentrations of thrombin (0.5 units/ml) single platelets can be recovered that have lost practically all of their releasable serotonin and adenine nucleotides. These platelets are able to aggregate upon addition of low concentrations of ADP in the presence of fibrinogen. They aggregate in response to the ionophore A23, 187 in the absence of added fibrinogen, whereas sodium arachidonate-induced aggregation requires added fibrinogen. Thrombin-treated platelets change their shape in response to collagen in the absence of fibrinogen, and will aggregate upon the addition of collagen providing fibrinogen is present. This response to collagen can be blocked with aspirin but not with a mixture of creatine phosphate/creatine phosphokinase. Upon a second exposure to thrombin, thrombin-pretreated platelets do not change their shape and do not undergo aggregation. Thrombin-pretreated platelets will not retract a thrombin-induced fibrin clot unless ADP, sodium arachidonate, the ionophore A23, 187 or collagen are added together with thrombin.

The ability of thrombin-treated platelets to adhere to the exposed subendothelial surface of the rabbit aorta is reduced, compared with untreated control platelets. The thrombin-treated platelets shorten the bleeding time of thrombocytopenic rabbits. However, they are not as effective in shortening the bleeding time as normal control platelets. When injected into rabbits with a normal platelet count, the thrombin-treated platelets that circulate after infusion survive for the same length of time as untreated control platelets. These findings indicate that thrombin-induced platelet aggregation with extensive release of granule constituents is not irreversible and that thrombin treatment does not cause irreversible damage of all platelets that would lead to their immediate elimination from the circulation. Furthermore, these platelets can still be haemostatically effective. It is conceivable that platelets that have lost their amine storage granule contents during a release reaction in vivo, such as may occur in certain cases of intravascular coagulation and repeated episodes of thrombosis, may be found in the circulation of man.
Platelet Aggregation by Thimerosal
Authors: Leone G , Boni P , Vincenti A
Published: July 2018

Thimerosal, a sulphydryl inhibitor, induces aggregation of normal platelet rich plasma over a wide range of concentrations. Low doses induce a monophasic response preceded by a lag phase, high doses produce an immediate biphasic response.

Thimerosal induces platelet aggregation through its binding by sulphydryl groups.

Thimerosal induced aggregation is not mediated by ADP, it is not influenced by fibrinogen, von Willebrand factor, calcium, and magnesium ions of the medium.

Thimerosal induced platelet aggregation is normal in patients affected by thrombocyto-pathia (defect of ADP release) but not in patients affected by Glanzmann’s thrombasthenia. Mercaptopropionglycine, a substance which tends to preserve SH groups, inhibits platelet aggregation induced by thimerosal, thrombin, collagen, and ADP.

A mechanism is proposed for thimerosal induced aggregation and the role of SH groups also in ADP, thrombin and collagen induced aggregation is indicated.
Biological Properties of Dialysable Peptides Derived from Plasmin Digestion of Bovine Fibrinogen Preparations
Authors: Buczko W , Gaetano G. de , Franco R , Donati M. B
Published: July 2018

Dialysable peptides (M. W. less than 12,000) were obtained by plasmin digests of purified bovine fibrinogen. The biological effects of these peptides were studied in rats in three different test systems: ADP-induced platelet aggregation, isolated atria contractility and vascular permeability.

The effects induced by the peptides were: inhibition of ADP-induced platelet aggregation, increase in the frequency of isolated atria contractions and local increase in vascular permeability. All these activities were concentration dependent. Six micrograms of the peptides were still effective in increasing vascular permeability; in the in vitro systems the smallest effective dose ranged between 165 and 650 μg/ml.

Following elution through a Sephadex G-25 gel with bidistilled water, four fractions were obtained. The second fraction (M.W. about 5,000) was the most active, followed by the first and then the third one; the fourth fraction was inactive.

These data suggest that local accumulation of peptides in vivo may be of clinical relevancy.
Haemophilia in Australia
Authors: Rickard Kevin A.
Published: July 2018

The major problems currently facing haemophilia management in Australia relate to (1) a need for better co-ordination of our entire national effort for haemophilia therapy and (2) a need to improve the efficiency of our preparation of factor VII concentrates. If we could simply double or treble our factor VIII yields from the same volume of donor plasma many of our urgent treatment problems could be solved.
Deep Vein Thrombosis in Obstetric Patients: Diagnosis and Risk Factors
Authors: Boer Karin de , Büller Harry R , ten Cate Jan W , Levi Marcel
Published: July 2018

This study was performed to assess the prevalence of deep vein thrombosis (DVT) in consecutive obstetric patients with clinical symptoms of DVT, using impedance plethysmography (IPG) as the diagnostic method and to establish the safety of withholding anticoagulant therapy in patients with a repeatedly normal IPG. In addition, in patients with DVT the prevalence of coagulation and fibrinolytic disorders, which may explain the occurrence of venous thrombosis was investigated.Of the 77 obstetric patients with symptoms of DVT 32 (42%) had an abnormal IPG. The remaining 45 patients had a repeatedly normal IPG and showed no venous thromboembolism during a 6 months follow-up period. Twenty percent (six patients) of the patients with an abnormal IPG had a coagulation or fibrinolytic abnormality. These observations suggest that serial IPG can be used effectively in the management of obstetric patients with clinically suspected DVT and that hemostatic abnormalities are frequently found in those patients with DVT
Comparison of the In Vivo Anticoagulant Properties of Standard Heparin and the Highly Selective Factor Xa Inhibitors Antistasin and Tick Anticoagulant Peptide (TAP) in a Rabbit Model of Venous Thrombosis
Authors: Vlasuk George P , Ramjit Denise , Fujita Tsuneo , Dunwiddie Christopher T , Nutt Elka M , Smith Donna E , Shebuski Ronald J
Published: July 2018

An in vivo thromboplastin (TP)-induced venous stasis thrombosis model in rabbits was used to compare the efficacy of standard heparin with the selective factor Xa inhibitors, recombinant tick anticoagulant peptide (rTAP) and recombinant antistasin (rATS), in prophylactic prevention of thrombus formation. Heparin significantly reduced TP-induced clot formation at doses of 55 and 100 U kg−1 h−1 yielding clot weights of 9 ± 4 and 6 ± 2%, respectively. Clot formation was significantly decreased by i.v. infusions of rTAP at doses of 21, 37 and 64 Μg kg−1 min−1 resulting in normalized clot weights of 13 ± 3, 8 ± 2 and 2 ± 1%, respectively. rATS was approximately 10-fold more potent than rTAP, reducing normalized clot weights to 16 ± 5, 2 ± 1 and 1 ± 0.8% at rATS doses of 1.25, 2.5 and 5.0 Μg kg−1 min−1, respectively. These data suggest that factor Xa-mediated inhibition of coagulation with rTAP and rATS is as effective as conventional anticogulant treatment with heparin in preventing venous thrombosis.
The Characterisation of Thrombus Development in an Improved Model of Arterio-Venous Shunt Thrombosis in the Rat and the Effects of Recombinant Desulphatohirudin (CGP 39393), Heparin, and lloprost
Authors: Peters R F , Lees C M , Mitchell K A , Tweed M F , Talbot M D , Wallis R B
Published: July 2018

An existing arterio-venous shunt thrombosis model in the rat has been modified to increase its usefulness for the testing of antithrombotic agents and characterised using morphological and radiometric techniques. The thrombus formed on the cotton thread held in the shunt was found to be composed of platelet aggregates surrounded by red thrombus. After 30 min of blood flow there was a 15-fold increase in the platelet content of the thrombus and a 4-fold increase in the fibrin(ogen) content compared with an equivalent weight of whole blood.

Use of the anticoagulants recombinant desulphatohirudin (CGP 39393, 4 mg/kg, s.c.) and unfractionated heparin (800 IU/ kg, s.c.) showed that approx. 90% inhibition of thrombus weight and approx. 80% inhibition of fibrin(ogen) content could be achieved without significant effect on the platelet content. Conversely, using the platelet inhibitor lloprost (1 Μg kg−1 min−1), a reduction in thrombus weight of 50% was associated with 75% inhibition of platelet content and only 20% inhibition of fibrinogen). These observations suggest that the growth of this type of thrombus is largely the result of continued fibrin formation rather than continued platelet recruitment and activation.