STUDY OF STRESSED-DEFORMED STATE OF THE POLYGONAL ARCH COVERINGS OF WOOD

In this work the use of wooden I-beams with OSB wall as the load bearing elements for polygonal arch coverings of buildings of various spans are considered. Special steel connecting pieces can shape the polygonal arch coverings. Calculations of the constructions with a span of 12 and 18 meters and an analysis of their stress-strain state are given.In this work the use of wooden I-beams with OSB wall as the load bearing elements for polygonal arch coverings of buildings of various spans are considered. Special steel connecting pieces can shape the polygonal arch coverings. Calculations of the constructions with a span of 12 and 18 meters and an analysis of their stress-strain state are given

Hepatic veins reconstruction in right lobe liver transplantation from living related donor

Institutul Național de Chirurgie și Transplantologie “А.Shalimov”, Kiev, Ucraina, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Lobul hepatic drept (LHD) reprezintă cea mai frecvent utilizată grefă de transplant alogen la adulți. Prelevarea acestuia fără vena hepatică medie (VHM) poate fi însoțită de congestia segmentelor V și VIII și de sindromul masei mici de transplant la recipient, în timp ce prelevarea cu VHM se poate complica cu sindromul de ficat restant mic și insuficiență hep atică postoperatorie (IHP) la donator. O opțiune ar fi reconstrucția venelor hepatice ale segmentelor V și VIII și prelevarea grefei fără VHM. Scopul lucrării: Studierea rezultatelor diferitor tehnici de reconstrucție a fluxului venos hepatic în cazul transplantului alogen de LHD de la donator viu. Material și metode: Au fost studiate 73 transplanturi alogene de LHD de la donator viu. În 33 cazuri ca grefă de transplant a servit LHD prelevat cu VHM, plastia căreia a fost efectuată cu petic din vena portă a recipientului (tehnica „bumerang”). În 40 cazuri s-a prelevat LHD fără VHM, din care în 4 cazuri reconstrucția fluxului venos de la segmentele hepatice V și VIII s-a efectuat cu ajutorul unui petic sintetic sau autovenă. Prelevarea LHD cu VHM s-a efectuat doar în cazurile prenzenței venei hepatice segmentare IVb bine definite anatomo-radiologic. Vena hepatică dreaptă infero-posterioară a fost reconstruită doar avînd diametrul mai mare de 5 mm. Rezultate: IHP s-a dezvoltat la 5 (15,5%) recipienți în grupa cu VHM și la 16 (40%) recipienți fără VHM (p=0,03). Volumul hemoragiei (1230±20 ml și 1110±35 ml), durata intervenției (612±22 min și 560±39 min), timpul total al ischemiei (86±13 min și 72±14 min) între ambele grupuri nu au fost semnificativ diferite (p>0,05). Deasemenea nu s-au deosebit și complicațiile vasculare: 3 (9%) și 5 (12,5%), respectiv. În grupul cu VHM mortalitatea la 60 zile în cazul recipienților a fost 12,1% (4 cazuri) vs 15% (6 cazuri) în grupul fără VHM. IHP s-a dezvoltat la donatori în 4 (12,1%) cazuri în grupul cu VHM și în 4 (10%) cazuri în grupul fără VHM. Toți donatorii au fost externați la a 7-14-a zi. Rata complicațiilor infecțioase și biliare în ambele grupuri nu s-a deosebit. Concluzii: Prelevarea LHD cu VHM poate fi efectuată în siguranță în cazul prezenței la donator a venei segmentare IVb bine definite. Utilizarea transplantului LHD cu VHM permite scăderea semnificativă a ratei IHP la recipienți. În prezența unor vene afluente segmentare V și VIII de calibru mare în cazul prelevării LHD fără VHM este necesară reconstrucția acestora cu petic autovenos sau sintetic.Introduction: Right hepatic lobe (RHL) is the most commonly used graft for allogenic transplant in adults. Its collecting without middle hepatic vein (MHV) may be accompanied by congestion of V and VIII segments and by syndrome of small-mass transplant at recipients, while the collecting with VHM may be complicated by small remaining-liver syndrome and postoperative liver failure (PLF) at donors. One option would be the reconstruction of hepatic vein of segments V and VIII and taking graft without VHM. The aim: To study the results of different hepatic veins reconstruction techniques in right lobe liver transplantation from living related donor. Material and methods: We studied the results of 73 RHL transplants from a living related donor. In 33 cases, the RHL graft was used with MHV, its reconstruction being performed using auto-venous portal patch from recipient (the "boomerang" technique). In another 40 cases, the RHL graft was used without the MHV. Of these, in 4 cases was performed a reconstruction of V and VIII segmental veins using prosthesis or auto-venous patch. The collecting of RHL graft with MHV was performed only in the presence of well-defined radiographically and anatomically 4b sub-segmental vein. The right infero-posterior hepatic vein reconstruction was performed at a diameter greater than 5 mm. Results: PLF was revealed at 5 (15.5%) recipients with MHV and 16 (40%) recipients without MHV (p=0.03). The volume of bleeding (1230±20 ml and 1110±35 ml), the operating time (612±22 min and 560±39 min), total time of ischemia (86±13 min and 72±14 min) in both groups was not significant different (p>0.05). Also, the vascular complications were no special different 3 (9%) and 5 (12.5%), respectively. In the group with MHV the mortality at 60 days for recipients was 12.1% (4 cases) vs 15% (6 cases) in the group without MHV. PLF has been developed at 4 (12.1%) donors in group with MHV and 4 (10%) donors without VHM. All donors were discharged in 7-14 days. The rate of infectious and biliar complications in both groups was not different. Conclusions: The RHL graft collecting with MHV can be performed safely only in the presence of well-defined 4b subsegmental vein. The using of RHL transplant with MHV allows a significant decrease of PLF rate at recipients. If you have a large segmental venous tributaries from V and VIII segments in RHL graft collecting without MHV, it needs their reconstruction using prosthesis or auto-venous patch

15-years experience of living donor liver transplantation in Ukraine

Institutul Național de Chirurgie și Transplantologie “А.Shalimov”, Kiev, Ucraina, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Transplantul hepatic (TH) reprezintă unica opțiune de tratament radical în cazul patologiilor hepatice terminale. Din 2001 Institutul de Chirurgie și Transplantologie din Ucraina a realizat programul de TH de la donator viu. Scopul lucrării: Evaluarea rezultatelor TH pe perioada anilor 2001-2015. Material și metode: Au fost studiate rezultatele a 142 TH alogene de la donator viu, efectuate pe perioada anilor 2001-2015. Toți recipienții s-au aflat pe lista de așteptare în baza criteriilor UNOS. Indicațiile au fost: ciroza secundară diferitelor maladii (hepatita virală – 23,2%, hepatita autoimună – 9,15%, alte etiologii – 11,3%), ciroza criptogenă – 13,4%, atrezia biliară – 31,7% și tumorile hepatice – 11,3%. Investigarea donatorului a fost efectuată în conformitate cu protocolul prestabilit. Volumul grefei de transplant a fost calculat în baza datelor CT și RMN. Rezultate: Din 142 TH de la un donator viu în 73 cazuri s-a transplantat lobul hepatic drept, 14 – lobul stîng și 54 – secțiunea laterală stângă. Într-un caz, a fost realizat transplantul unimomentan de la 2 donatori vii. Vârsta medie a recipienților a fost – 22,3±8,2 ani (7 luni – 58 ani), 75 dintre aceștia au fost de sex masculin. Toți recipienții au prezentat ciroză decompensată clasa C după Child-Pugh. Valoarea medie a stării funcționale integrale hepatice a fost de 12,5±1,2 puncte. Ascita refractară preoperator a fost observată la 47 pacienți, 8 pacienți au prezentat episoade recurente de peritonită bacteriană spontană, 6 pacienți – sindrom hepatorenal de tip II. Pierderea de sînge intraoperator a fost 2400±900 ml, durata operației – 16±3 ore. Durata ischemiei la rece: 45±17 min, la cald – 48±12 min. Durata medie a spitalizării recipienților a constituit – 32±8 zile. Mortalitatea postoperatorie precoce a fost în 23 cazuri – 16,1%. Rata de supraviețuire la 1 an – 73,9% și la 5 ani – 66,9%. Concluzii: TH alogen de la donator viu reduce semnificativ timpul de aflare a recipientului în lista de așteptare și îmbunătățește supraviețuirea. Rezultatele TH sunt comparabile cu rezultatele studiilor străine, ceea ce face posibilă recomandarea efectuării pe larg a TH, ca metodă de tratament radical a pacienților cu patologii hepatice terminale.Introduction: Liver transplantation is the only radical treatment method of terminal liver diseases. From 2001, Institute of Surgery and Transplantology of Ukraine has been performing allogenic transplantation program from the living donor. Aim: the current study is oriented on the survey of transplantation results for 2001-2015. Material and methods: The study surveyed 142 patients’ transplantations from living donors, performed from 2001 to 2015. All recipients were on the waiting list for transplantation from a relative, according to UNOS Criteria. The indications for inclusion in the waiting-list were: liver cirrhosis as a consequence of different diseases (viral hepatitis – 23.2%; autoimmune hepatitis – 9.15%, other etiology – 11.3%), cryptogenic cirrhosis – 13.4%, biliary atresia – 31.7% and liver cirrhosis – 11.3%. Donor investigations have been done according to the created protocol. Transplant’s volume was calculated with CT and MRI. Results: From 142 patients who supported living donor transplantation, in 73 cases has been performed right hemi-liver transplantation, in 14 – of the left hemi-liver, and in 54 – of the left lateral section. In one case has been performed simultaneous transplantation from 2 living donors. The average recipient’s age was 22.3±8.2 years (7 months – 58 years), 75 recipients were males. All patients with cirrhosis were of C-class according to Child-Pugh. The average index of integral liver functionality has been 12.5±1.2 points. Resistant ascitis in preoperative period was detected in 47 patients, in 8 – recurrent episodes of spontaneous bacterial peritonitis, in 6 – II type hepatorenal syndrome. Intraoperative bleeding was 2400±900mL, time of operation – 16±3 hours. The lasting of cold-ischemia was 45±17 min, warm ischemia – 48±12 min. The average duration of postoperative period for recipients was 32±8 days. Early postoperative lethality was noted in 23 cases – 16.1%. Yearly survival – 73.9%, and the actual 5-year survival rate was 66,9%. Conclusions: Living donor transplantation significantly reduces the patient time from waiting-list and increases patient survival rate. The obtained transplantation results are comparable with the results of international studies, and allow us to recommend transplantation for a large group of indications, as a method of selecting treatment for terminal liver pathology patients

Statistical shape modeling of multi-organ anatomies with shared boundaries

Introduction: Statistical shape modeling (SSM) is a valuable and powerful tool to generate a detailed representation of complex anatomy that enables quantitative analysis of shapes and their variations. SSM applies mathematics, statistics, and computing to parse the shape into some quantitative representation (such as correspondence points or landmarks) which can be used to study the covariance patterns of the shapes and answer various questions about the anatomical variations across the population. Complex anatomical structures have many diverse parts with varying interactions or intricate architecture. For example, the heart is a four-chambered organ with several shared boundaries between chambers. Subtle shape changes within the shared boundaries of the heart can indicate potential pathologic changes such as right ventricular overload. Early detection and robust quantification could provide insight into ideal treatment techniques and intervention timing. However, existing SSM methods do not explicitly handle shared boundaries which aid in a better understanding of the anatomy of interest. If shared boundaries are not explicitly modeled, it restricts the capability of the shape model to identify the pathological shape changes occurring at the shared boundary. Hence, this paper presents a general and flexible data-driven approach for building statistical shape models of multi-organ anatomies with shared boundaries that explicitly model contact surfaces.Methods: This work focuses on particle-based shape modeling (PSM), a state-of-art SSM approach for building shape models by optimizing the position of correspondence particles. The proposed PSM strategy for handling shared boundaries entails (a) detecting and extracting the shared boundary surface and contour (outline of the surface mesh/isoline) of the meshes of the two organs, (b) followed by a formulation for a correspondence-based optimization algorithm to build a multi-organ anatomy statistical shape model that captures morphological and alignment changes of individual organs and their shared boundary surfaces throughout the population.Results: We demonstrate the shared boundary pipeline using a toy dataset of parameterized shapes and a clinical dataset of the biventricular heart models. The shared boundary model for the cardiac biventricular data achieves consistent parameterization of the shared surface (interventricular septum) and identifies the curvature of the interventricular septum as pathological shape differences

Late results of embolization of a portal hepatic vein branches in patients, suffering extended hepatic tumors

Objective. To analyze late results of preoperative  embolization of the portal hepatic vein branches (EPHVB) in patients, suffering extended hepatic tumors and extremely border-like small calculated residual hepatic volume(CRHV). Маterials and methods. From 2004 to 2014 yr the extended hepatic resection (HER) was performed in 285 patients, to whom EPHVB was applied (the main group), аnd in 353 patients as well, but without endovascular preparation (control group). In both groups dynamics of laboratory indices, structure of complications and lethality, late survival were studied. Results. In the main group a trustworthily lower rate of an acute hepatic insufficiency and connected with a lower postoperative lethality - accordingly 2.3 and 4.6%, comparing with a control group - 9.3 and 8.8%, were suggested. The laboratory data dynamics have witnessed a lesser intensiveness of postoperative hepatocytolysis and lesser degree of the hepatic synthetic function lowering in the main group, what have confirmed a better functional adaptation of hepatic residual in patients, to whom preoperative EPHVB was applied. Conclusion. Preoperative EPHVB permits to lower the postoperative complications and lethality rate in patients, suffering hepatic tumors, due to better functional adaptation of hepatic residual

Размер и форма частиц полипиррола в водных растворах поли-( N-винилпирролидона)

Based on the IR spectroscopy data and on the analysis of rheological characteristics of polypyrrole aqueous suspension stabilized with poly-(N-vinylpyrrolidone) we conjecture that a physical lattice composed with poly-(N-vinylpyrrolidone) is formed, where the lattice points are the polypyrrole chain aggregates interlaced with poly-(N-vinylpyrrolidone) chains. It was shown that there is a hydrogen bond between the constitutional repeating units of poly-(N-vinylpyrrolidone) and polypyrrole. It was determined that the size of the particles of the disperse phase decreases with the increase of poly-(N-vinylpyrrolidone) molecular weight. It was also determined that the size of particles increases with the increase of the mass fraction of polypyrrole aqueous suspension. It was shown that the disperse phase particles are rod-like, and the increase of molecular weight of poly-(N-vinylpyrrolidone) in an aqueous solution results in additional lengthwise stretching of particles. It was also shown that the viscosity of the stabilized poly-(N-vinylpyrrolidone) aqueous suspension follows the Einstein law.На основании данных ИК-спектроскопии и анализа реологических характеристик водной суспензии полипиррола, стабилизированной поли-( N -винилпирролидоном), выдвинуто предположение об образовании физической сетки, формируемой цепями поли-( N -винилпирролидона), узлами которой являются агрегаты цепей полипиррола, переплетенные с цепями поли-( N -винилпирролидона). Установлено уменьшение размера частиц дисперсной фазы при увеличении молекулярной массы поли-( N -винилпирролидона)

Хирургические аспекты формирования кишечных стом в онкологии. Обзор литературы

The formation of intestinal stoma is performed during routine and emergency operations. This review provides a brief historical overview of the main stages of development of methods colo- and ileostomy. The article presents indications, as well as possible complications that may happen during operative treatment. It is occurred that there is little evidentiary material of colo- or ileostomy in evaluating complications that are associated with the various surgical methods of intestinal stoma formation. The purpose of this review is to summarize the current data on stoma formation and determine the method to use.Формирование кишечной стомы выполняется при плановых и экстренных операциях. В работе представлен краткий исторический обзор основных этапов развития методов формирования коло- и илеостом. Приведены показания, а также возможные осложнения при выполнении данного оперативного лечения. При оценке осложнений, связанных с формированием кишечной стомы, и определении преимуществ различных хирургических методов выявлено, что доказательных данных о преимуществе коло- или илеостом накоплено мало. Целями данного обзора является обобщение современных данных о кишечных стомах и определение метода выбора для применения в практике

КИНЕТИКА И МЕХАНИЗМ ОКИСЛИТЕЛЬНОЙ ПОЛИМЕРИЗАЦИИ 2-МЕТИЛАНИЛИНА

The kinetics of oxidative polymerization of 2-methylaniline in hydrochloric acid aqueous solution in the presence of ammonium peroxydisulfate as the oxidant was studied. The presence of autocatalysis was demonstrated, and the reaction mechanism was suggested. On the basis of the mechanism a kinetic model of oxidative polymerization of 2-methylaniline was built. The model is in satisfactory agreement with the experimental results.И сследована кинетика окислительной полимеризации 2-метиланилина в солянокислом водном растворе в присутствии пероксидисульфата аммония в качестве окислителя. Показано наличие автокатализа, предложен механизм реакции. На основании механизма построена кинетическая модель окислительной полимеризации 2-метиланилина, находящаяся в удовлетворительном соот-ветствии с результатами эксперимента

Кинетика и механизм окисления 2,4,6-триметиланилина

The kinetics of oxidation of 2,4,6-trimethylaniline hydrochloride with ammonia peroxydisulfate in an aqueous solution was studied by the potentiometric method. It was shown that the reaction proceeds as the second order process. The rate constants of one-electron transfer from 2,4,6-trimethylaniline molecule to peroxydisulfate ion were determined and are 1.46, 2.3, and 3.17 l/(mol.sec) at 30, 35 and 40° С , respectively. The activation energy of one-electron transfer from 2,4,6-trimethylaniline molecule to peroxydisulfate ion is 61 kJ/mol, the entropy of activation is –63 J/(mol К ), and the enthalpy of activation is 58.5kJ/mol. It was determined that 2,4,6-trimethylaniline is not prone to oxidative polymerization. This indicates that cation-radicals of aromatic amines which act as active centers of aniline oxidative polymerization are formed. The fact that there is no autoacceleration during oxidation of 2,4,6-trimethylaniline hydrochloride indicates that the oxidative polymerization of aniline is an autocatalytical process.Потенциометрическим методом исследована кинетика окисления 2,4,6-триметиланилина под действием пероксидисульфата аммония в водном растворе. Показано, что скорость реакции подчиняется уравнению второго порядка. Определены константы скорости и энергия активации окисления 2,4,6-триметиланилина, а также предложен механизм реакции