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Over the last decades outcomes for rectal cancer surgery have improved with increasing survival and lower recurrence rates. Nevertheless, functional disorders are still frequent. Low anterior resection with total mesorectal excision (TME) in patients with rectal cancer has improved oncological outcomes. However, most of them will have significant changes in quality of life, including varying degree of bowel dysfunction. Aim of this study was to analyse prevalence of LARS (low anterior resection syndrome) in patients with rectal cancer after miniinvasive restorative resection and to define its risk factors.Between March 2016 and June 2018, patients who underwent elective miniinvasive (laparoscopic or robotic) rectal resection were enrolled. Bowel dysfunction was evaluated by LARS questionnaire and filled out 6, 12, and 24 months after primary operation or after ileostomy closure. 98 patients completed the questionnaires - 58 laparoscopic operations, 34 robotic and 6 open procedures. 69 patients underwent TME, tumor-specific mesorectal excision 21 patients. 8 patients underwent transanal TME. The clinical characteristics, surgical perioperative and postoperative outcomes did not differ between these groups. Only, significantly more patients underwent neoadjuvant radiotherapy in the robotic group (p=0.004).59.8% patients reported major LARS 6 months after surgery and 29.7% after 24 months. Protentional risk factors are age (p.

Near-infrared (NIR) fluorescence angiography (FA) is an augmented reality (AR) technique. When used in the operating room, it allows colorectal surgeons to visualize and evaluate intestinal blood flow in real time, identify lymph nodes, ureters, or peritoneal metastases. Evaluation of perfusion with FA in augmented reality mode has an impact on reducing the ALR (anastomotic leakage rate) in rectal resections.Data analysis of patients after minimally invasive surgery (MIS) for middle and lower rectal adenocarcinoma with total mesorectal excision (TME) using fluorescent angiography (FA) with indocyanine green (ICG) (100 patients, 20152019) were subsequently compared with a historical control group (100 patients) operated on for the same diagnosis before the introduction of the FA-ICG method (20122015) using minimally invasive approach (MIS). The patients were operated on consequently at one workplace.In fifteen patients (15%), the resection line was shifted due to insufficient perfusion detected by FA-ICG. The incidence of AL was lower in the group with FA compared to the group without FA (9% vs. 19%, p=0.042,#967; test). A retrospective analysis of the group revealed a significant risk factor (RF) for the anastomotic leak, namely diabetes (p=0.036) and, among others, a protective factor, application of the transanal drain (NoCoil) (p=0.032).The introduction of new procedures and the use of new technologies, such as the use of the FA method in the AR mode in resections of the rectum with TME for cancer can lead to a reduction in the incidence of anastomotic leakage.

The primary goal of this study was to evaluate peroperative and early postoperative results of laparoscopic and robotic surgery for rectal cancer with total mesorectal excision (TME) and with primary anastomosis.404 patients were enrolled in the study, divided in two cohorts and compared retrospectively: a laparoscopic group (n=236) versus a robotic (TME + primary coloanal anastomosis) group (n=168). The evaluated cohorts were comparable in sex, age, BMI, ASA score, distal tumor margin from anal verge and neoadjuvant chemoradiotherapy. More advanced tumor stages were observed in the robotic group (p=0.009).The duration of robotic resection was significantly longer compared to laparoscopic resection (p.

Negative pressure wound therapy is a healing modality utilizing continuous or intermittently applied vacuum to the wound bed. Nowadays is available a vacuum system supported by an automated instillation with volumetric control. It`s main therapeutic benefit is the dilution of the exudate, which reduces the viscosity and secures the «delicate» necrectomy.Presentation of the temporary results of a prospective randomized study comparing the effectiveness of both therapeutic techniques. Entirely 41 patients were enrolled in the study from November 2016 to September 2018. The primary goal of the project is to compare the length of therapy, the number of surgical debridements and evaluation the financial costs. Secondary targets are observed changes in biological load and bacterial spectrum.The duration of the therapy was 2 days shorter in the experimental group compared to the control sample. However, the average number of applications was higher. Defects with the instillation system were characterized by a shorter cleaning phase (p=0.057). The secondary suture was reached in the experimental group at 84.2% and in the control group at 72.7%. The differences in these parameters were not statistically significant. Fascial disruption was observed in the trial group in 2 patients. The financial costs of the material used was significantly higher in patients with irrigation system (p.

The rotation dynamics of the spin probe TEMPO in glycerol from ESR is compared with the ortho-positronium ( o-Ps ) annihilation from PALS and interpreted using the relaxation dynamics from BDS. Rotation time scale within the slow motion regime exhibits two Arrhenius regions with the characteristic ESR temperature, T X1 τ , close to the characteristic PALS temperature, T b1 L , which is related to the secondary β process above T g . Next, a slow to fast motion regime transition at the characteristic ESR temperature, T c τ , close to the characteristic PALS temperature, T b2 L , followed by non-Arrhenius fast motion regime region is fully coupled with the primary α process.

Aim Enzalutamide and abiraterone represent new therapeutical options in the treatment of metastatic castration-resistant prostate cancer (mCRPC). The aim of the presented study was retrospective analysis of clinical experience and efficacy of enzalutamide or abiraterone in the postchemo indication in patients with mCRPC. Patients and methods A total of 32 mCRPC patients were evaluated. All patients received one or more lines of chemotherapy. Twenty-three patients were treated by enzalutamide, nine patients were treated by abiraterone. We defined two parameters: over all survival and progression-free survival. Results The median follow-up was 6.5 months. A total of 10 patients treated by enzalutamide progressed (43.47%) and eight patients died (34.78%). A total of five patients treated by abiraterone progressed (55.56%) and one patient died (11.11%). We did not observe any statistical difference in over all survival (HR 0.2362, 95% CI 0.0295- 1.8942; p = 0.102) and in progression-free survival (HR 0.9853, 95% CI 0.2934- 3.308; p = 0.939) between enzalutamide and abirateron. Conclusion Our retrospective study demonstrated similar efficacy of enzalutamide and abiraterone in mCRPC patients previously treated by chemotherapy.

The aim of the study was to evaluate the results of fluorescence angiography for assessing anastomotic perfusion after resection of the sigmoid colon and rectum since its introduction into clinical practice at the authors´ workplace and to evaluate the incidence of necessary resection line repositioning based on the quality of perfusion, and also to record any complications in anastomotic healing.Retrospective unicentric analysis of prospectively collected data from patients with resection of the sigmoid colon and rectum with primary anastomosis. The patient set included 50 patients, 27 males and 23 females; the median age was 64.5 years (33-80). Forty-four patients were indicated for resection for cancer of the sigmoid colon or rectum, while 6 patients had a benign disease. Twenty-nine patients underwent total mesorectal excision with coloanal mechanical or hand-sewn anastomosis and 21 underwent resection of the sigmoid colon or upper rectum with mechanical anastomosis. Prior to the construction of the anastomosis, assessment of perfusion of the anastomotic segments by near infrared (NIR) indocyanine green (ICG) fluorescence angiography was performed in all patients. The quality of perfusion of the mesocolon and bowel wall and its impact on moving the resection line and complications of anastomotic healing 30 days postoperatively were all evaluated.Assessment of perfusion using fluorescence angiography was technically successfully performed in all 50 patients. In 5 cases (10%) the resection line had to be moved for signs of poor perfusion of the bowel wall. Postoperatively, healing of the anastomosis was complicated in four patients (8%). Dehiscence was recorded in 3 patients (10.3%) with total mesorectal excision and in 1 patient (4.8%) after resection of the sigmoid colon and upper rectum.The presented results indicate that fluorescence angiography may lead to a decrease in the incidence of anastomotic dehiscence after colorectal resections by mapping in detail the perfusion of the anastomosed segments.Key words: fluorescence angiography - indocyanine green - anastomotic leak - colorectal resection.

Parastomal hernia is a common stoma complication. Surgical treatment is necessary in approximately 10 to 20% of cases. Mesh hernia repair gives significantly better results. The authors present their initial experience with laparoscopic repair of parastomal hernia using the modified Sugarbaker technique.In the period from January 2011 to December 2013, 15 patients with a symptomatic parastomal hernia underwent laparoscopic repair with modified Sugarbaker technique. All patients had a parastomal hernia at the site of terminal colostomy after abdominoperineal resection. 14 patients underwent primary hernia repair, 1 patient was operated on for recurrence of parastomal hernia after open hernia repair. Parietex Parastomal mesh was used for hernia repair in all cases.Laparoscopic repair was performed successfully in all patients. The mean operating time was 45 minutes (range: 2080 minutes). The mean postoperative hospital stay was 3 days (range: 26 days). No serious postoperative complication was recorded. In the postoperative period, a recurrent symptomatic hernia was found in 1 of 15 patients (6.7%) with reintervention 17 months after primary surgery.Laparoscopic hernia repair of parastomal hernia with modified Sugarbaker technique seems to be a safe method with a very low risk of postoperative complications, including hernia recurrence. .

Resection procedures for colorectal cancer are burdened with a relatively high number of complications. The aim of this study is to define risk factors associated with the development of postoperative complications based on retrospective data analysis.From January 1 st 2007 to December 31st 2012, 1093 patients underwent surgery for colorectal cancer. Retrospectively, we selected a group of 406 patients who underwent planned, elective colon resection for colon cancer. Open surgery was performed in 158 patients (38.9%), laparoscopic resection in 248 patients (61.1%). Based on initial staging of the disease, there were 85 patients (20.9%) in stage I, 137 patients (33.8%) in stage II, 110 patients (27.1%) in stage III and 74 patients (18.2%) in stage IV. Postoperative complications were evaluated according to Clavien - Dindo classification.Grade I complications were observed in 34 patients (8.4%), grade II in 25 patients (6.2%), grade III in 43 patients (10.6%), grade IV in 7 patients (1.7%) and grade V in 8 patients (2.0%). The highest incidence of complications was observed in left colon resection procedures (41.1%), open resections (39.8%), procedures lasting longer than 301 minutes (50%), patients older than 81 years (41.6%) and in procedures performed by the youngest, less experienced surgeon (40.6%).Our results confirmed that the type and approach of surgical procedure, patients age and surgeons experience are risk factors associated with a higher incidence of postoperative complications. High-risk surgical patients should be operated on by experienced surgeon who regularly performs a high number of resection procedures.

A phenomenological model linking the macroscopic volume from dilatometry with the microscopic free volume from positron annihilation lifetime spectroscopy is presented. The temperature dependences of both quantities enable to obtain the so-called initial temperature Ti at which dynamic free volume change sets in, the corresponding initial volume Vi, and subsequently, all free volume characteristics. Application of this model on the literature data of a typical low-molecular weight glass former, o-terphenyl, leads to the findings that (i) Ti ≅ TK the Kauzmann temperature and (ii) a packing fraction of the extrapolated equilibrium liquid at Ti is close to the closest regular packing of hard spheres. The published viscosity−temperature data over 12 decades of magnitude are correlated with the free volume hole fraction fh, as determined from the PALS results, via the WLF−Doolittle type equation. These findings indicate that the orthopositronium (o-Ps) is able to detect the part of the total free volume distri...

The macroradical decay in poly(methyl methacrylate) samples with different thermal histories was investigated in the temperature interval 20–100 °C using ESR spectroscopy and the second order kinetic model. The rate constants exhibit two different regimes with the transitions atTtr=68±1°C which are independent of thermal treatment. ForT Ttr the rate constants as well as the corresponding activation parameters are sensitive to history because of different physical microstructures. The compensation law, i.e., the linear relation between lnko, eff andEeff, was analyzed in terms of the so-called compensation quantitieskc andTc and a proximity betweenTc=Ttr andTo=53±3 °C — Vogel temperature for α-segmental dynamics was found. A comparison of kinetic and dynamic data suggests that the decay of terminal macroradicals in the low-temperature region is controlled by secondary relaxations and that the α-mobility contributes to a more rapid decay at higher temperatures belowTg.

Analyses of large genomes are hampered by high proportions of repetitive DNA, that make the assembly of short sequence reads difficult. This is also the case for meadow fescue (Festuca pratensis Huds.), one of predominant grass species in temperate and Northern regions with the genome size estimated at 1C = 3,175 Mbp. This species is known for its ability to survive under freezing conditions and it has been used widely in intergeneric hybridization with various ryegrass species to produce superior Festulolium cultivars. Here we describe attempts to dissect the meadow fescue’s genome into smaller fractions—individual chromosomes and groups of chromosomes. Following the methods of flow cytogenetics developed for legumes and cereals, we have developed a chromosome sorting protocol for grasses and currently we are able to sort F. pratensis chromosome 4 (the largest in the genome) and two groups of three chromosomes each: 2, 3, 7 and 1, 5, 6. As the first step we sequenced chromosome 4 by Illumina with 50x coverage and assembled low copy and genic regions. This facilitated detailed comparative analysis with sequenced genomes of rice, Brachypodium and sorghum and provided the first insight into the genome composition of this species. The possibility to purify chromosome 4 opens the way for a more efficient analysis of genetic loci on this chromosome that control important agronomic traits, such as freezing tolerance. Moreover, purified chromosomes are excellent templates for PCR screening as well as cytogenetic and physical mapping.

The analysis of non-equilibrium quasistatic CU curves of MIS capacitors reveales that it is possible to distinguish several groups of states differing by their respective effective capture cross sections. A relation between the demarcation energy that separates states in quasi-equilibrium from those in non-equilibrium at the oxide-semiconductor interface, and the equivalent frequency of the quasistatic CU method, is derived. Using the Berglund integral, the surface potential can be calculated even under non-equilibrium conditions. States in the upper half of the gap are found to have up to three orders higher capture cross section for holes compared to that of states in the lower half of the gap.

Changes in the current-voltage characteristics and charge DLTS spectra of Schottky diodes on semi-insulating GaAs after irradiation by protons at different energies and doses are presented and discussed. Apart from a progressive degradation of the Schottky barriers with enhanced proton energy and dose, there is a threshold, positioned between 1014 and 1015protonscm2, for observing trap-limited transients.

We discuss DLTS andC-V measurements on Al/Si3N4/Si(2nm)/n-GaAs (≈ 5×1017 cm−3) structures. Three discrete deep traps superimposed on a U-shaped interface-state continuum have been identified, with respective thermal energies:E c−0.53 eV,E c−0.64 eV, andE v+0.69 eV. The second one (0.64 eV) is presented as an electric field sensitive level, its enhanced phonon-assisted emission resulting in a rapid shift of the corresponding DLTS peak to lower temperatures, as the applied (negative) reverse bias voltage increases. An interpretation through emission from the quantum well, introduced by means of the intermediate ultrathin Si layer, has failed.

The segmental size in amorphous poly(ethylene terephthalate) (PET) was determined by two methods: a) from deformational behavior of amorphous samples in the elastic state by optical birefringence measurement, and b) from dynamic behavior of a small spin probe by ESR measurement of correlation times. The use of the network model for orientation of segments in amorphous polymer and of the generalized free-volume model for re-orientation of the probe in the amorphous phase gave comparable values ofn=2.3 and 2.1 structural units/segment. We conclude that trans ⇌ gauche conformational transitions of rather small macromolecular segments are the basic motion mechanism in αa-segmental mobility in PET.

Silicon wafers with p-n junctions are contaminated by nickel and the temperature behaviour of the reverse current of these p-n junctions is investigated. Nickel-related deep energy levels are studied by DLTS measurement. The dominant energy level of Ni is at Ev + 0.31 eV. The illumination and annealing sensitivity of this level is also observed. An attempt is made to explain qualitatively this phenomenon. Siliziumscheiben mit p-n-Ubergangen werden mit Nickel dotiert, und die Temperaturabhangigkeit des Sperrstroms an diesen Ubergangen gemessen. Die mit Nickel korrelierten tiefen Niveaus werden mit Kapazitatstransienten-Spektroskopie (DLTS) untersucht. Das dominante Niveau fur Nickel wird bei Ev + 0,31 eV gefunden und erweist sich als beeinflusbar durch Beleuchtung und Temperung. Es wird eine qualitative Deutung dieses Phanomens vorgeschlagen.

C–U and DLTS characteristics are measured of aluminium oxide on GaAs obtained by plasma anodisation at different temperatures, Tox, of the substrate. Hysteresis of the flat-band voltage, injection currents, and Fermi-level pinning are observed. Phonon-assisted tunnelling with subsequent trapping in aluminium oxide is the most probable mechanism of the electron injection. The GaAs–oxide interface quality is better for Tox = 150 °C than for Tox = 30 °C. Es werden die C–U- und DLTS-Charakteristiken von Aluminiumoxid auf GaAs gemessen, das durch Plasmaanodisierung bei verschiedenen Substrat-Temperaturen Tox erhalten wird. Hysterese der Flachbandspannung, Injektionsstrome und Ferminiveaufixierung werden beobachtet. Phononenassistiertes Tunneln mit nachfolgendem Anhaften im Aluminiumoxid stellt den wahrscheinlichsten Mechanismus fur die Elektroneninjektion dar. Die GaAs–Oxid-Grenzflachenqualitat ist fur Tox = 150 °C besser als fur Tox = 30 °C.

Polycarbonate was subjected to long-term stress by transverse bending. Stressed, as well as non-fatigued, samples were irradiated by gamma radiation in evacuated ampoules. The concentration of free radicals was measured by ESR in the course of gradual heating of the samples. It appeared that the free radicals in the samples subjected to long-term stress were more stable than the free radicals in the non-fatigued samples. This suggests that the arrangement of polymer chains changes during fatigue and the free volume in the proximity of radical centres decreases so that the transfer of these centres to adjoining chains is retarded.

Analysis of the structure of nine polymers, in terms of the average size of free volume at T 50G for spin probe Tempo, reveals an empirical connection between this microstructural characteristic of matrices and the change in reorientational regime of the spin probe.

The cyclic stress-strain curve of single-slip-oriented single crystals of low-stacking-fault-energy alloy Cu-22%Zn was determined on a large number of specimens. There was an expressive plateau extending from a plastic shear strain amplitude of about 7 × 10−4 to about 7 × 10−3. The plateau shear stress amplitude was 43 MPa.

The WLF equation is one of the most important formulae in polymer physics and for a long time is used to describe the universal non - Arrhenius behavior of viscosity η or of relaxation time τ, Williams et al (1955). Originally, the WLF eq. for the shift factor a (T) was interpreted within the free volume concept using the Doolittle equation, Doolittle(1951): $$ln{\text{ }}a(T) = \ln \eta (T)/\eta (T_g ) = \ln \tau (T)/\tau (T_g ) = B_f [l/f(T) - l/f(T_g )]$$ (1)

Phenomenologically, the mobility properties of supercooled liquids such as viscosity (M = η), relaxation time (M = τ) and diffusion coefficient (M = 1/D) are usually described by the Vogel -Fulcher (VF) equation or, equivalently, by the Williams - Landel - Ferry (WLF) equation, Williams et al (1955). Both the equations are often interpreted within the free volume concept at a phenomenological level using the empirical Doolittle equation, Doolittle (1951) or/and at a quasi-molecular one by means of a free volume model of Cohen, Turnbull (1959). The WLF Doolittle formula for the shift factor a(T) = M(T)/M(Tg) can be expressed as follows: $$ln{\text{ }}a(T) = B_f [l/f(T) - l/f(T_g )]$$ (1)

Forest floor is considered a major feature distinguishing forest from agricultural soils. Forest floor develops as forest stands grow and is composed of more or less altered plant-tissue biomass accumulated on the soil surface. Our study’s aim was to find whether properties of both the organic layers and mineral soil differ according to the land-use history of the sites compared. Each site included an afforested area of immature 50-year-old spruce forest (AFF) on formerly agricultural land plus an adjacent area of old-growth 100-year-old spruce stand (FOR). The localities are situated at altitudes ranging between 600 and 850 metres above sea level. From the results of our study it can be concluded that both forest floor and mineral soil had higher pH and Ca concentration at formerly agricultural sites. C/N ratio is significantly lower in afforested soil. First-generation humus was significantly higher in phosphorus. El piso forestal es considerado una de las principales características distintivas de los suelos forestales frente a los agrícolas. El piso forestal se desarrolla según crecen las masas forestales y se compone de tejidos de vegetales de la biomasa más o menos alterados acumulados en la superficie del suelo. El objetivo de nuestro estudio fue determinar si las propiedades de las capas orgánicas y minerales del suelo difieren de acuerdo a la historia del uso del suelo de los sitios. Cada sitio incluye un área reforestada de bosque de pinabete inmaduro de 50 años de edad (AFF) en antiguo terreno agrícola, más un área adyacente madura de pinabete de 100 años de edad. Las localidades se encuentran en altitudes que oscilan entre 600 y 850 metros sobre el nivel del mar. De los resultados de nuestro estudio se puede concluir que tanto el suelo del bosque como el suelo mineral tenían un pH más alto y mayor concentración de Ca en los sitios agrícolas abandonados. La relación C/N es significativamente menor en los suelos reforestados. La primera generación de humus presentó un significativamente mayor contenido en fósforo.

This paper presents a combined description of the ortho-positronium (o-Ps) response from positron annihilation lifetime spectroscopy (PALS) and viscosity data on bis[m-(m-phenoxy) phenoxyphenyl] ether within the free volume version of the two-order parameter (TOP) model of disordered phase. The quasi-sigmoidal form of the temperature dependence of the o-Ps lifetime, τ3, over a wide temperature interval, can be described by an expression with the distribution function for liquid-like domains 1−F(T) which follows from a phenomenological analysis of the viscosity using the modified Vogel–Fulcher–Tamman–Hesse (MVFTH) equation. This simultaneous description indicates a close connection between the PALS response and the viscosity behavior for the matrix and gives support for the liquid-like and solid-like domain physical picture of all the physical states of the disordered phase.

A detailed study has been made of the rotation of the spin probe 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TANOL) in the regime of fast motion in poly(isobutylene) using the activation energy; a free volume model of the probe mobility in the condensed phase is described. Results of the applications of exact and approximate treatments of the generalized free volume model are compared. An analysis of the geometrical and energy parameter of α-mobility has shown that the motion of the probe in the elastic state of the amorphous phase is controlled by local conformational mobility of small segments of the macromolecules.

Metal-oxide-semiconductor structures are fabricated on an n-type GaAs substrate at room temperature by means of plasma anodic oxidation of aluminium films evaporated on the GaAs substrate. Current and charge transient spectroscopies and low frequency C-U measurements are applied to the MOS capacitors. The optimum processing condition for the minimum interface-state-density is found to be related to the properties of the Al film. Three apparent activation energies of the dominant DLTS peak (Ec - 0.5 eV, Ec - 0.67 eV, Ec - 0.72 eV) for three concentrations of donors (1024, 2.7 × 1023, and 1.4 × 1022 m−3) are determined; the differences in the values of the energies can be estimated as a consequence of the Poole-Frenkel effect with an extrapolated value of the true energy Ec - 0.75 eV. From this point of view the observed DLTS peaks are attributed to the same defect, which can be connected with two simultaneous processes in the course of oxidation: (1) with the out migration of Ga atoms through the oxide layer and (ii) with the forming of a high resistivity O-compensated layer between the oxide and the semiconductor. Mittels anodischer Plasmaoxydation von Aluminiumschichten auf GaAs-Substraten werden Metall-Oxid-Halbleiterstrukturen auf einem n-leitenden GaAs-Substrat bei Zimmertemperatur prapariert. Strom- und Ladungstransientenspektroskopie und Niederfrequenz C-U- Messungen werden fur die Untersuchung der MOS-Kondensatoren benutzt. Es wird gefunden, das die optimalen Prozesbedingungen fur minimale Grenzflachenzustandsdichte mit den Eigenschaften der Al-Schicht verknupft sind. Drei auftretende Aktivierungsenergien des dominierenden DLTS-Maximums (Ec - 0,5 eV, Ec - 0,67 eV, Ec - 0,72 eV) fur drei Donatorkonzentrationen (1024, 2.7 × 1023, and 1.4 × 1022 m−3) werden bestimmt, die Differenzen in den Energiewerten lassen sich als Folge des Poole-Frenkel-Effekts berechnen, mit einem extrapolierten Wert der wahren Energie Ec - 0,75 eV. Von diesem Standpunkt aus werden die beobachteten DLTS-Maxima demselben Defekt zugeordnet, der mit zwei simultanen Prozessen im Verlauf der Oxydation verbunden sein kann : 1) mit der Migration von Ga-Atomen durch die Oxidschicht und 2) mit der Bildung einer hochohmigen O-Kompensationsschicht zwischen dem Oxid und dem Halbleiter.

The influence of the gaseous environment on fatigue crack propagation and on the threshold values in an MnCrNi austenitic steel was examined using atmospheres of dry and moist argon and hydrogen and using moist gases containing traces of chlorine ions. The effect of hydrogen gas and water vapour on the crack rate is less than that for ferritic and martensitic steels, but nevertheless it is easily measurable, especially at low stress intensities. The presence of chlorine ions even in very low concentrations increases the fatigue crack propagation rate substantially and is a prerequisite for crack growth under a sustained load. The results are explained in terms of the hydrogen-induced embrittlement model.

A general version of the Kusumoto-Bullock free-volume model for reorientation dynamics of spin probe in solid polymers is described. Its application enables one to obtain simultaneously the size parameter of a segment and the kinetic-energy parameter of segmental mobility. These data, along with theoretical knowledge of the conformational microstructure and conformational dynamics, allow a discussion of molecular mobility in terms of concrete conformation-segmental motion mechanisms. Participation of one-barrier transitions of the typePptqQ→Pp′g ± q′Q, and two-barrier transition of the type gauche-migration, creation and annihilation of kink sequence was observed for linear polyethylene. In agreement with the conformational microstructure, it was found for isotactic polypropylene that Schatzki's crankshaft motions of four-member segments might be involved.

The values of van der Waals radii rW's according to Bondi [1] and Stokes [4] were summarized for the chosen atoms of the first, second and third row of MPT namely H, Li, C, N, O, F, Na, Mg, Si, P, S and Cl. They were used in the study on how an actual rW value depends on the electronic state of a given atom and how the interaction of the atom with environment affects this value. For all mentioned atoms individual functional dependences of rW on the net charge of atom were found taking into account the effect of electronic cloud alone and the interaction with surroundings moreover. The formulae obtained were tested on some examples.

In experimental work on dogs, was performed a myocardial ischemia of differing duration. By means of a non-suture mammary-coronary artery anastomosis, a revascularisation was achieved. We realise that the diagnosis of the anastomostic potency using normal methods is not sufficiently clear. For this reason we tried to improve our diagnostic potential by means of antibody detection.

Die vorliegende Arbeit beruht auf der Auswertung von 890 praoperativen und von 400 postoperativen Angiographien bei Kranken, die wegen Arterienverschlusse der unteren Gliedmasen operiert wurden. Es wird betont, das die postoperative Kontrollarteriographie zur Routineuntersuchungsmethode gehoren sollte, weil sie unentbehrlich fur die Fruhdiagnose der verschiedenen postoperativen Komplikationen ist. Sie ist weiter notwendig fur die Indikation zur Reoperation und fur die Wahl des Operationsverfahrens. Es hat sich auch gezeigt, das die postoperative Angiographie wichtig fur die Beurteilung der Funktion der rekonstruktiven Operationen, fur das Studium der Veranderungen des Kollateralkreislaufes und fur die Entdeckung der Ursachen der Spatthrombose ist. The present paper is based on data obtained from 890 pro-operative and 400 post-operative angiograms of patients who underwent surgery for arterial occlusive disease of the lower limbs. It is stressed that postoperative angiography should be used routinely, since it is essential for the early diagnosis of various postoperative complications. It is also necessary, if a decision has to be made, to re-operate, and for the choice of appropriate surgical techniques. Post-operative angiography has also been shown to be important for evaluating function of the reconstructed vessels, for a study of changes in the collateral circulation and in order to discover causes of late thrombosis.