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As in a previous paper (Galád [CITE]), the search for effective perturbers among asteroids is done using the same method and during the same time period. The only difference is in the number of asteroids that were processed – 24 599 instead of 9511. Special attention is paid to comparison between perturbations due to (2) Pallas and (10) Hygiea. It is confirmed that the latter has a larger effect on the motion of main belt asteroids, perhaps by a factor of three. This is a reason to include its mass in asteroid orbit determinations.
In addition to the Big Four main belt asteroids – (1) Ceres, (2) Pallas, (4) Vesta, (10) Hygiea – the masses of many other large asteroids, such as (11) Parthenope, (13) Egeria, (15) Eunomia, (16) Psyche, (24) Themis, (29) , (39) Laetitia, (45) Eugenia, (52) Europa, (65) , (121) Hermione, (451) Patientia, and (511) Davida, could be achieved by the end of this decade using astrometric data. In general, over the next decade small asteroids (with much higher numbers than above) will be used more thoroughly for mass determination of large asteroids.

We report patient-reported outcomes and complications associated with contemporary periacetabular osteotomy (PAO) surgery in treating symptomatic acetabular dysplasia and compare these outcomes with total hip arthroplasty (THA) in patients with similar demographic details. Two consecutive cohorts included patients between aged 18 to 40 years who had undergone either PAO (100 hips; 24 male, 76 female) or THA (55 hips; 18 male, 37 female). At a mean follow-up of 5.9 years (2 to 13), there was significant improvement in the modified Harris hip pain (p < 0.001, PAO and p < 0.001, THA), function (p < 0.001, PAO and p = 0.001, THA), and total scores (p < 0.001, PAO and p < 0.001, THA) within each cohort. There were no significant differences in the clinical outcome scores between the groups. Complication rates were low and similar in each cohort (p = 0.68). Similar to THA, contemporary PAO surgery is a clinically effective procedure that improves function and activity levels, provides pain relief and is associated with an acceptable complication rate.Cite this article: Bone JointJ 2015;97-B:1322–7.

We investigated whether, in the management of stable paediatric fractures of the forearm, flexible casts that can be removed at home are as clinically effective,cost-effective and acceptable to both patient and parent as management using a cast conventionally removed in hospital. A single-centre randomised controlled trial was performed on 317 children with a mean age of 9.3 years (2 to 16). No significant differences were seen in the change in Childhood Health Assessment Questionnaire index score (p = 0.10) or EuroQol 5-Dimensions domain scores between the two groups one week after removal of the cast or the absolute scores at six months. There was a significantly lower overall median treatment cost in the group whose casts were removed at home (£150.88 (sem1.90) vs£251.62 (sem2.68); p <  0.001). No difference was seen in satisfaction between the two groups (p = 0.48).Cite this article: Bone Joint J2013;95-B:1714–20.

We present a review of different micropatterning technologies for flexible elastomeric functional nanocomposites with a particular emphasis on mold material and processes for production of large size substrates. The functional polymers include electrically conducting and magnetic materials developed at the Micro-instrumentation Laboratory at Simon Fraser University, Canada. We present a chart that compares many of these different conductive and magnetic functional nanocomposites and their measured characteristics. Furthermore, we have previously reported hybrid processes for nanocomposite polymers micromolded against SU-8 photoepoxy masters. However, SU-8 is typically limited to substrate sizes that are compatible with microelectronics processing as a microelectronics uv-patterning step is typically involved, and de-molding problems are observed. Recently, we have developed new processes that address the problems faced with SU-8 molds. These new technologies for micropatterning nanocomposites involve new substrate materials. A low cost Poly(methyl methacrylate) (PMMA) microfabrication technology has been developed, which involves fabrication of micromold via either CO2laser ablation or deep UV. We have previously reported this large-scale patterning technique using laser ablation. Finally, we compare the two processes for PMMA producing micromolds for nanocomposites.

Ecological restoration efforts in large rivers generally aim to ameliorate ecological effects associated with large‐scale modification of those rivers. This study examined whether the effects of restoration efforts—specifically those of island construction—within a largely open water restoration area of the Upper Mississippi River (UMR) might be seen at the spatial scale of that 3476 ha area. The cumulative effects of island construction, when observed over multiple years, were postulated to have made the restoration area increasingly similar to a positive reference area (a proximate area comprising contiguous backwater areas) and increasingly different from two negative reference areas. The negative reference areas represented the Mississippi River main channel in an area proximate to the restoration area and an open water area in a related Mississippi River reach that has seen relatively little restoration effort. Inferences on the effects of restoration were made by comparing constrained and unconstrained models of summer chlorophyll a(CHL), summer inorganic suspended solids (ISS) and counts of benthic mayfly larvae. Constrained models forced trends in means or in both means and sampling variances to become, over time, increasingly similar to those in the positive reference area and increasingly dissimilar to those in the negative reference areas. Trends were estimated over 12‐ (mayflies) or 14‐year sampling periods, and were evaluated using model information criteria. Based on these methods, restoration effects were observed for CHL and mayflies while evidence in favour of restoration effects on ISS was equivocal. These findings suggest that the cumulative effects of island building at relatively large spatial scales within large rivers may be estimated using data from large‐scale surveillance monitoring programs. Published in 2010 by John Wiley & Sons, Ltd.

This paper presents a new approach to fabricate low cost metallization on PMMA substrates based on commercially available Mirrored-Extruded Acrylic (mirrored Plexiglass / mirrored PMMA). The patterned metal could be subsequently employed as a mask for deep-UV PMMA micropatterning of polymer-MEMS devices. The process presented eliminates the use of sputtered metals and can be scaled up to substrates of sizes 12 inch × 24 inch or larger for batch fabrication. Mirrored Extruded Acrylic has a coating of 6 micron thick vacuum metalized aluminum or copper with an adhesive backing. We have discovered that the adhesive backing can be easily etched away by using ethanol, exposing the aluminum or copper, which can be micropatterned by standard photolithographic processes. We have fabricated various microstructures in aluminum, including microelectrodes and Van de Paw structures. Resistivity measurements show that the resistivity of the micro-machined aluminum is equal to lower than 4.8 × 10-6-m, which is sufficient for sensor electrodes or signal routing applications for MEMS/ MST devices.

We present the large scale micro-pattering of an electrically conducting multiwalled carbon nanotube (MWCNT) polydimethylsiloxane (PDMS) nanocomposite polymer prepared by high frequency (42 kHz) ultrasonic agitation of MWCNTs in the PDMS polymer matrix. Large scale micropatterning of the MWCNT-PDMS nanocomposite is achieved via soft lithography employing a 12" × 24" poly-methyl methacrylate (PMMA, commercially known as Plexiglass) micromold. The process has a 20µm minimum feature size. The PMMA micromold is fabricated by laser ablating 5-mm thick, 12" × 24" sheets using the Universal Laser System's VersaLASER© laser cutter system which employs a CO2laser. We have characterized and compared the resistivity of 1cm × 0.5cm × 0.5cm MWCNT-PDMS structures with varying weight percentage (wt-%) of MWCNT (1-10% wt%) in the PDMS matrix with a result that the percolation threshold is achieved at 2 wt-%. Furthermore, we have demonstrated the ability to fabricate large numbers of microelectrodes with a length of 3.0 cm, width of 500µm, and height of 400µm. The resistivity of these electrodes was found to be equal to 9.93m with a deviation of approximately 10%, indicating uniformity across large areas of the substrate. We have also demonstrated a large scale 12" × 24 hybrid microfabrication process for combining micromolded MWCNT-PDMS nanocomposite microstructures with nonconductive PDMS polymer.

Reliable estimates of abundance are needed to assess consequences of proposed habitat restoration and enhancement projects on freshwater mussels in the Upper Mississippi River (UMR). Although there is general guidance on sampling techniques for population assessment of freshwater mussels, the actual performance of sampling designs can depend critically on the population density and spatial distribution at the project site. To evaluate various sampling designs, we simulated sampling of populations, which varied in density and degree of spatial clustering. Because of logistics and costs of large river sampling and spatial clustering of freshwater mussels, we focused on adaptive and non‐adaptive versions of single and two‐stage sampling. The candidate designs performed similarly in terms of precision (CV) and probability of species detection for fixed sample size. Both CV and species detection were determined largely by density, spatial distribution and sample size. However, designs did differ in the rate that occupied quadrats were encountered. Occupied units had a higher probability of selection using adaptive designs than conventional designs. We used two measures of cost: sample size (i.e. number of quadrats) and distance travelled between the quadrats. Adaptive and two‐stage designs tended to reduce distance between sampling units, and thus performed better when distance travelled was considered. Based on the comparisons, we provide general recommendations on the sampling designs for the freshwater mussels in the UMR, and presumably other large rivers. Published in 2009 by John Wiley & Sons, Ltd.

Summary: We present the preparation, improved micro‐patterning, and electrical property characterization of COOH‐ functionalized mutli‐walled carbon nanotube (MWCNT) and polydimethylsiloxane (PDMS) conductive nanocomposite polymers that can be employed for lab on a chip applications. The nanocomposites are prepared by mixing functionalized MWCNTs into an uncured PDMS matrix and employing high frequency ultrasonics (∼ 42‐50 kHz) using a horn tip probe. The prepared nanocomposites are micromolded using soft lithography techniques down to a feature size of 25 µm against a micropatterned SU‐8 polymer master. An array of peg like microstructures have been fabricated with a radii of 25 µm and height of 100 µm, that are embedded on a non‐conductive PDMS substrate using novel and improved fabrication techniques. The percolation threshold of the prepared nanocomposite is achieved at 1.5 weight percentage (wt.%) of COOH‐ functionalized MWCNT in the PDMS matrix. Resistivity levels at 2 wt.% of functionalized MWCNTs are 62 Ω‐cm or better, which is an improvement over our previously reported nanocomposite resistivity value of 100 Ω‐cm at 2 wt.% of nonfunctionalized MWCNT's in a PDMS matrix. The nanocomposites also have fairly uniform dispersion and no agglomeration of COOH‐ functionalized MWCNT as shown by SEM analysis. Furthermore, the nanocomposites show a negative temperature coefficient of resistivity (NTCR), making them ideal candidates for micropatternable temperature microsensors for lab on a chip systems.

A crossover in the ability of two distinct ruthenium‐based metathesis pre‐catalysts to effect the synthesis of dialkenylboronic esters in solution and on the solid‐phase was observed. Specifically, while the Grubbs 2nd generation pre‐catalyst 3affords a greater degree of conversion to product than the Hoveyda–Grubbs pre‐catalyst 2in a solution‐phase enyne‐metathesis reaction, this trend is reversed in the solid‐phase variant. Systematic investigation showed this trend to be general, regardless of variations in the homoallylic alcohol and alkynylboronic ester components of the reaction, as well as in the type of solid support employed. Experiments to determine a mechanistic hypothesis for this trend highlighted the significance of the ruthenium remaining bound to the substrate after metathetic rearrangement and found the presence of phosphine ligand to be detrimental to the success of the solid‐phase reaction. Therefore, these results suggest an expanded role for phosphine‐free pre‐catalysts, such as 2, in challenging solid‐phase metathesis reactions.

A synthesis strategy for aqueous-cored calcium phosphate nanoparticles is presented that combines ease of preparation, reproducibility, size control, stability, and mean thickness control. Suspension stability and shell thickness control were achieved through the introduction of a “capping” molecule, carboxyethylphosphoric acid (CEPA). Using this method, suspensions of calcium phosphate shells were produced with a size distribution of 120−185 ± 50 nm and predictable mean shell thickness from 10 to 40 nm that were stable up to a month, even in the presence of 200 mM salt and 2.5 g/dL albumin.

Proliferative status and multidrug resistance play a key role in determining cell response to chemotherapy. There is a need to develop multiple labeling method that allows simultaneous assessment of multidrug resistant (MDR) phenotype, proliferative status, apoptosis related changes in mitochondrial potential, in chemosensitive and chemoresistant tumor cell populations. A three-color labeling was performed using Hoechst 33342 (DNA), JC1 (mitochondrial potential), and a far red fluorescent membrane intercalating dye: PTIR271 (proliferation). Combined staining of DNA and mitochondrial potential allows identification of subpopulations expressing and MDR phenotype mediated by P-glycoprotein (Pgp), and, in Pgp negative subpopulations, identification of apoptotic cells and evaluation of cell cycle status in viable cells. Addition of a far red fluorescent membrane intercalating dye, PTIR271, allows simultaneous monitoring of cell division status by dye dilution in both drug sensitive and drug resistant populations. This triple labeling is an interesting method to study the proliferation status of drug sensitivity and drug resistance in viable tumor cells. © 2004 Wiley-Liss, Inc.

A highly diastereoselective, microwave-induced Claisen rearrangement of an appropriately substituted propargylic enol ether allows the formation of the sterically congested C8−C14 bond of azadirachtin. When combined with a radical-mediated cyclization of the corresponding allene, this sequence offers rapid entry to the framework of azadirachtin.

The influence of an endothermic process on propagation of a premixed laminar flame in an exothermic branched chain is considered. The assumption of a quasi–steady–state for the radical intermediate species allows the branched–chain kinetics to be represented as a second–order reaction system. We show that, depending on the initial concentrations of the fuel and the endothermic reactant and the enthalpies of reaction for the two processes, two different flame solutions can exist. A flame frontexists if the exothermic charge in the system exceeds the endothermicity and the temperature rises monotonically through the flame profile. If the endothermicity exceeds the exothermicity, then it is possible to observe flame–pulsesolutions in which the temperature increases from its initial value far ahead of the reaction zone to some maximum value before falling back to its initial value far behind the reaction zone. There is no apparent discontinuity in the observed wave speed as the transition from one solution to another occurs. At higher endothermicity, there is ‘quenching’ leading to the ‘failure’ of the flame to develop into a sustained propagating structure. The critical condition for flame failure has been computed numerically as a function of the other system parameters and shows the characteristics of a saddle–node bifurcation with quenching from some non–zero minimum flame speed.An extension to the model is introduced to examine the situation in which the endothermic reaction leads to the production of a radical scavengerthat catalyses the thermoneutral termination of radical chain carriers. It is shown that this additional channel decreases the critical endothermicity for flame quenching. The model is discussed in the context of a premixed flame subject to quenching by water mist with dissolved ionic salts.

Muramic acid serves as a marker for the presence of bacterial cell wall debris in mammalian tissues. There have been a number of controversial and sometimes conflicting results on assessing the levels of muramic acid in health and disease. The present report is the first to use the state-of-the art technique, gas chromatography-tandem mass spectrometry, to identify and quantify the levels of muramic acid in tissues. Muramic acid was not found in normal rat brain or spleen. However, when tissues were spiked with muramic acid, it was readily identified. The detection limit was <1 ng of muramic acid/100 mg (wet weight) of tissue. The levels of muramic acid reported in diseased human spleen and spleen of arthritic rats, previously injected with bacterial cell walls, were 100- to 1,000-fold higher. In the present study, muramic acid was also readily detected in the cerebrospinal fluid of patients with pneumococcal meningitis (6.8 to 3,900 ng of muramic acid/ml of cerebrospinal fluid). In summary, there can be an enormous difference in the levels of muramic acid found in different mammalian tissues and body fluids in health and disease. This report could have great impact in future studies assessing the role of bacterial cell wall remnants in the pathogenesis of certain human inflammatory diseases.

The steady states of the dynamical Endex CSTR problem are analysed in terms of degenerate bifurcation (singularity) theory. Steady–state analysis is used in two ways: (1) as a device to assist in understanding and predicting complex dynamicalbehaviour; and (2) as a practical design and operational tool, by applying the concept of quasi–static parameter variation. In the bifurcation analysis, consideration is given to the effects of thermal mismatching, kinetic mismatching, and variations in the thermal exchange, mass flux and heat loss rate parameters, on the structure of the parameter space. The qualitative equivalence of the bifurcation structure of the kinetically matched perfectly coupled adiabatic Endex scheme and the single–reaction adiabatic CSTR is demonstrated, with reference to the role of the reaction enthalpy effects. Numerical analysis shows that either kinetic mismatching of the reactions or imperfect heat exchange may introduce Hopf bifurcations into the adiabatic system. This is a result that is both philosophically and practically important because it shows that limit cycles are not restricted to non–adiabatic thermokinetic systems. The coefficients of thermal exchange, mass flux and heat loss are found to induce distortions of the surface of saddle–node bifurcations (the limit–point shell) through codimension–2 bifurcations. The steady–state and oscillatory–state degeneracies are discussed with reference to the design and operational implications for a working system.

Here we describe the Endex reactor, a novel scheme for thermal control of potentially runaway reactions. The reactor is a composite of individual reactors, each of which houses either an exothermal or an endothermal reaction mixture. In this paper, which is Part I, we introduce the concept of an endothermally stabilized chemical reactor as an enthalpy–coupled thermokinetic system, and give it precise mathematical expression in the form of a four–dimensional dynamical system, for the special case of a continuous stirred tank reactor. The principle of enthalpy conservation is applied in the adiabatic case, which togethery with the consequence of taking the limit of a system parameter, collapses the structure of the state space to two dimensions. Criteria are defined for which the system is free of all kinds of thermal misbehaviour. This important dynamical result defines bounds for a large region of the parameter space within which this reactor may be operated safely.

The portal vein contributes little to the blood supply of established liver metastases in the presence of a patent hepatic artery. However, its role in the perfusion of early metastatic liver disease remains controversial. We have quantified the relative contribution of the portal vein and hepatic artery to the internal circulation of small liver tumours. These studies were conducted in a new rat model of liver metastases generated by the intraportal injection of cultured tumour spheroids. A total of 633 lesions were studied in 18 animals using radioisotope tracer microspheres. Nodules ranged from 0·5 to 6·0 mm in diameter, 92 per cent being 3·0 mm or less. The ratio of radioactivity in tumour compared with normal tissue (T:N ratio) was determined after simultaneously injecting microspheres into the portal and arterial circulation of each animal. The mean hepatic artery T:N ratio was significantly greater than that of the portal vein for all tumour sizes studied (P< 0·01). Nodules 0·5 mm in diameter had a mean (s.e.m.) hepatic artery T:N ratio of 1·50 (0·12) in comparison with a mean portal vein ratio of 0·13 (0·04). Tumour nodules 2·0 mm in diameter had a mean (s.e.m.) hepatic artery T:N ratio of 1·26 (0·11) in comparison with a mean portal vein ratio of 0·06 (0·01). The overall T:N ratio for both routes decreased with increasing tumour size. These results indicate that hepatic tumours as small as 0·5 mm already have an established internal vasculature perfused predominantly by the hepatic artery. In contrast, the portal vein contributes insignificantly to the internal perfusion of these lesions. These results have significant implications for adjuvant locoregional therapy in gastrointestinal cancer.

Abstract: A class of nonlinear equations describing the steady propagation of a disturbance on the infinite interval in one dimensional space are shown under certain conditions to admit solution with a unique velocity of propagation. The class of equations describe both initial and final homogeneous steady states which are asymptotically stable with respect to uniform perturbations, in contrast to the Fisher equation, which does not.

Summary Processional trails (foraging expeditions) of the black termiteLongipeditermes longipes (Haviland) from a nest changed frequently during observations in a secondary rainforest on Penang Island, Malaysia, over a four month period. Nearly all of the length covered by the trails was above the ground along dead branches and shrubs and trees. The distance covered by the trails ranged from 6 to over 39 metres. Processional activity appeared to be influenced strongly by climatic conditions and during wet weather none was usually recorded. Most activity was observed in the morning between 8.00 and 11.30 am.

The queen makes a very simple nest structure which appears to be a common design for mostMyrmeciaspecies. However, after the appearance of the first workers the nest structure changes slowly as the colony grows larger to one typical of the species. Although many species, if not all, have a typical nest structure, two basic designs appear evident in theMyrmecia. The first is a simple structure with normally one main shaft, and little or no mound, while the second is a more diffuse and complex structure usually with three or more main shafts and a large mound. Notes on their location, size, and other significant features are given. Details are also given of the adult populations counted in 56 nests representing 20 species and their brood composition. The composition of most colonies appeared to vary seasonally. Larger worker populations were collected in nests with a complex structure than in those with a simple nest structure. La reine construit un nid très simple selon un modèle commun à la plupart des espèces deMyrmecia. Cependant, après l'apparition des premières ouvrières et à mesure que croît la colonie, la structure du nid change lentement pour devenir typique de l'espèce. Bien que beaucoup d'espèces, sinon toutes, aient un nid de structure typique, deux modèles de base caractérisent lesMyrmecia. L'un est simple et consiste habituellement en une cheminée principale et peu ou pas de dôme. L'autre, moins net et plus compliqué, comporte habituellement trois cheminées, ou davantage, et un grand dôme. Des indications sont données sur l'emplacement, la taille et d'autres caractéristiques significatives des nids. Des précisions sont aussi fournies sur les populations adultes dénombrées dans 56 nids représentant 20 espèces et sur la composition du couvain. La composition de la plupart des colonies a changé en fonction de la saison. Les ouvrières ont été récoltées en plus grand nombre dans les nids à structure compliquée que dans les nids simples.

Myrmecia froggattiForel andM. variansMayr workers show monomorphism with limited size variability, while those ofM. simillimaexhibit biphasic monomorphism with considerable size variation. Coefficient of variability values calculated for four characters provided a good measure of species size variation. Frequency histograms of head length against head width were distinetly unimodal in one colony ofM. froggattiand three colonies ofM. varians, and bimodal in the five colonies ofM. simillima. Les ouvrières deMyrmecia froggattiForel et deM. variansMayr présentent un monomorphisme avec une faible variabilité de la taille, tandis que celles deM. simillimamontrent un dimorphisme avec une considérable variation de la taille. Les valeurs des coefficients de variabilité calculés pour quatre caractères fournissent une bonne mesure de la variation spécifique de la taille. Les histogrammes de fréquence du rapport longueur/largeur de la tête sont unimodaux pour une colonie deM. froggattiet trois colonies deM. varianset bimodaux pour cinq colonies deM. simillima.

The utility of microspheres as targeted drug delivery agents is addressed with reference to using heat during formulation and to administration in combination with hyperthermia. It was demonstrated that rate of loading of the drug doxorubicin onto resin microspheres is enhanced under conditions of elevated temperature but this was shown to increase the incidence of microsphere aggregation. Total amount of drug loaded was related to time rather than temperature such that low temperature loading for up to 24 h produced optimum quality injectates. However, release of doxorubicin from microspheres was significantly increased during elevations of temperature to 43°C. Thus, during hyperthermia doxorubicin release can be increased to provide periods of high drug availability targeted to tumour tissue for concomitant thermochemotherapy with microspheres. The therapeutic benefit derived from this combined therapy was assessed in 20 rabbits with VX2 carcinoma implanted in the liver. Hyperthermia was delivered by 2450 MHz microwave applicator to the exteriorized liver at 43°C for 30 min, while chemotherapy was administered by intratumoural injection of doxorubicin microspheres (2·3 mg) into each tumour. Both hyperthermia and chemotherapy alone significantly reduced the size of tumours 10 days following treatment (p<0·01). However, in animals treated with both modalities, the size of tumours was significantly less than either treatment alone (p<0·05). These results provide a strong rationale for combining hyperthermia with targeted chemotherapy using microspheres.

An analysis is presented for a model of a two-species predator-prey system where each species can be harvested or stocked. Using methods from bifurcation theory the qualitative nature of the steady-state solutions is examined. The effect of harvesting and stocking rates and the prey carrying capacity is examined in detail.

The adherence of Streptococcus pneumoniae to human nasopharyngeal epithelial cells was studied as a possible determinant in the development of acute otitis media (AOM). Pneumococcal isolates were obtained from the nasopharynx (NP) and middle ear fluid of infants followed from birth in a prospective study of pneumococcal carriage and infection. The adherence of 33 middle ear fluid isolates from 19 infants with AOM was compared with 143 strains recovered from NP cultures taken from each child both at the time of their acute infections and on other occasions. We studied 171 NP isolates from 29 “carrier” infants, who had no pneumococcal infections, for comparison. Adherence properties were not associated with any particular pneumococcal capsular types, nor were adherent strains more frequent among infants with AOM. There was no evidence to support the hypothesis that pneumococci associated with AOM have a special propensity for adherence. Adherence was a frequent characteristic of pneumococci recovered from the NP, especially in connection with upper respiratory tract infection, and may be required for the establishment of colonization but was not a property that discriminated between carriage strains and those causing AOM.

The influence of liver hyperthermia on hepatic arterial and portal venous blood flow to tumour and normal hepatic tissue was examined in a rabbit VX2 tumour model. Hyperthermia was delivered by 2450 MHz microwave generator to exteriorized livers in 18 rabbits. Blood flow was measured in both portal vein and hepatic artery using radioactive tracer microspheres before, during and 5 min after intense (>43°C) hyperthermia. During hyperthermia a decrease in total liver blood flow was composed primarily of a decrease in hepatic arterial blood flow to tumour tissue. Tumours were supplied almost exclusively by the hepatic artery and thus total tumour blood flow was significantly depressed during heating. The decreased tumour blood flow persisted after the cessation of hyperthermia and was indicative of vascular collapse in the tumour tissue. Temperature differentials in tumour compared to normal tissue ranged from 5°C to 8°C during hyperthermia because of the lower tumour blood flow. The portal vein exerted minimal influence on temperatures attained in the tumour tissue during hyperthermia but would have mediated normal liver tissue heat loss.