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Introduction: Extracorporeal blood purification techniques have become a well-established part of routine practice in intensive care units. The issue of major concern while applying these techniques is to ensure appropriate anticoagulation to prevent the clotting of the circuit. Aim: The aim of this paper is to present regional anticoagulation as a method which is currently used in continuous extracorporeal blood purification techniques. Material and methods: This work is based on the available literature and the authors' experience. Results and discussion: Anticoagulation used to prevent the clotting of the circuit in extracorporeal blood purification techniques may be regional or systemic. Regional anticoagulation inhibits clotting only in the extracorporeal circuit. In this case either sodium citrate together with calcium substitution or heparin with protamine sulfate is used. Systemic anticoagulation involves the inhibition of clotting in the extracorporeal circuit and in the patient's body. Regional citrate anticoagulation (RCA) is obtained with the use of citrate. With this technique calcium substitution is necessary in order to prevent hypocalcemia. Other possible complications include alkalosis, metabolic acidosis, hypercalcemia and hypomagnesemia. This paper presents also some practical aspects of regional anticoagulation during continuous renal replacement therapy (CRRT) Conclusions: The application of RCA has contributed to a wider use of CRRT in intensive therapy units. The greatest advantage of this method is almost complete elimination of bleeding complications associated with the therapy. It enables effective blood purification in the patients in whom the use of heparins is contraindicated. This fact has found confirmation in Kidney Disease: Improving Global Outcomes (KDIGO) guidelines. [ABSTRACT FROM AUTHOR]

Introduction: Extracorporeal blood purification techniques have become a well-established part of routine practice in intensive therapy units. Ensuring appropriate anticoagulation to prevent the clotting of the circuit is the major concern while applying these techniques. Aim: The aim of this paper is to present methods of systemic anticoagulation which are currently used in continuous extracorporeal blood purification techniques. Material and methods : This work is based on the available literature and the experience of the authors. Results and discussion: The prevention of clotting in the extracorporeal circuit may be achieved through regional or systemic anticoagulation. Systemic anticoagulation is usually achieved by administration of unfractionated heparin. The most common complications include bleeding; additionally, there is a risk of type II thrombocytopenia occurring. Systemic anticoagulation may also be provided through administration of low molecular weight heparins. Some research papers have discussed the use of thrombin antagonists (argatroban, bivalirudin) and heparinoids (danaparoid, fondaparinux), as well as platelet inhibitors as systemic anticoagulants. It is also possible to conduct extracorporeal blood purification without anticoagulation. Conclusions: The introduction of continuous extracorporeal blood purification techniques into everyday practice of intensive care units has brought many unquestioned benefits to the patients treated in this setting. On the other hand, it means that doctors need to show an in-depth knowledge of the anticoagulation methods. Despite the wider use of regional anticoagulation during continuous renal replacement therapy, systemic anticoagulation is still important. This is especially when therapies with high blood flow are performed and contraindications to citrate use are present. [ABSTRACT FROM AUTHOR]

Achiral stilbene polycatenars forming smectic, columnar or cubic phase depending on the terminal chains length, were studied. The cubic Im3m phase exhibited optical activity originating in twisted face-to-face molecular aggregates. The optical activity of the phase is preserved upon sample crystallization, providing evidence of a transfer of chirality on a molecular level. [ABSTRACT FROM AUTHOR]

Gyroid cubic phases are interesting for both scientists and engineers due to possible applications in electronic devices. New series of dimeric molecules, despite their flexible molecular structure, can display double gyroid cubic phase with Ia3d symmetry and lattice parameter corresponding to double molecular length. The cubic phase is structurally related to columnar phase and both phases often coexist in the same temperature window. Apparently, for studied compounds stronger molecular asymmetry promotes cubic structure. Interestingly, for the examined compounds the transition between two isotropic liquids was observed. [ABSTRACT FROM AUTHOR]