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Mechanical metamaterials with variable stiffness recently gained a lot of research interest, as they allow for structures with complex boundary and load conditions. Herein, we highlight the design, additive manufacturing, and mechanical testing of a new kind of bending-dominated metamaterial. By advancing from well-established mechanical metamaterials, the proposed geometry allows for varying the stiffness in the three spatial directions independently. Therefore, structures with different orientational properties can be designed, ranging from isotropic to anisotropic structures, including orthotropic structures. The compression modulus can be varied in the range of several orders of magnitude. Gradual transitions from one unit cell to the next can be realized, enabling smooth transitions from soft to hard regions. Specimens have been additively manufactured with acrylic resins and polylactic acid using Digital Light Processing and Fused Filament Fabrication, respectively. Two different numerical models have been employed using ABAQUS to describe the mechanical properties of the structure and verified by the experiments. Compression tests were performed to investigate the linear elastic properties of isotropic structures. Numerical models, based on three-point-bending test data, have been employed to study orthotropic structures. Compression test results for orthotropic and anisotropic structures are shown to highlight the independent variability. The manufacturing of the structures is not limited to the presented techniques and materials but can be expanded to all available additive manufacturing techniques and their respective materials. For a video of the compression tests of a specimen with three different compression moduli along the spatial axes, see the Supplementary Data available online.

In this study, we tested the hypotheses that, relative to the maximum capacities, ballroom dancing is more intensive for females than males, and that the hold technique (female vs. male) regulates dancing intensity. Ten dance couples were tested in a maximal treadmill test, competition simulation, and stationary dance hold position. Peak heart rate and relative oxygen consumption were measured during the tests, except that oxygen consumption was not measured during competition simulation. Regardless of gender, heart rate increased similarly in the treadmill test and in the competition simulation. In the treadmill test, females achieved an oxygen consumption of 78% of the males (p p

Numerous studies have investigated lipoprotein(a) (Lp(a)) plasma concentrations in patients with ESRD, a patient group with an enormous risk for atherosclerosis. The reported differences in Lp(a) between controls and patients vary from a decrease of 49% to an increase of more than 1,000%. However, data are not consistent, mostly because of problems with statistical analysis, and only limited data are available for patients treated by continuous ambulatory peritoneal dialysis (CAPD). To estimate the significance of Lp(a) in ESRD and to demonstrate the statistical pitfalls concerning Lp(a) in case-control studies, a large multicenter study including 702 patients treated by either hemodialysis (HD) (N = 534) or CAPD (N = 168) was conducted, and results were compared with results from 256 healthy controls. Both patient groups showed significantly elevated Lp(a) levels in comparison with controls: 23.4 +/- 25.0 mg/dL (P < 0.005; HD) and 34.6 +/- 38.4 mg/dL (P < 0.0001; CAPD) versus 18.4 +/- 22.8 mg/dL (controls). CAPD patients showed significantly higher Lp(a) values than did patients treated by HD (P < 0.001). The difference between the two treatment groups possibly reflects an overproduction of Lp(a) to compensate for protein losses in CAPD patients. Both treatment groups included significantly more patients with Lp(a) values greater than the 75th percentile (25.6 mg/dL) of the control group (33.9 and 41.7% for HD and CAPD, respectively; P < 0.005). The higher Lp(a) values in patients were not explained by differences in isoform frequencies and the increase in Lp(a) was apolipoprotein(a) type specific: only patients with high-molecular-weight apolipoprotein(a) isoforms showed a significant elevation in Lp(a) levels. The increased plasma concentrations of Lp(a) may contribute to the high risk for atherosclerosis in ESRD, especially in patients treated by CAPD. Finally, it is believed that small sample sizes are responsible for the diverging results in Lp(a) literature.

Although glomerular damage plays a well-established and important role in the pathomechanism of diabetic nephropathy, it alone does not fully explain the progression of renal complications in long-term diabetes mellitus. We discuss experimental evidence showing involvement of the postglomerular microvessels (peritubular capillaries and venules) in diabetic microangiopathy. This involvement is manifest in increased permeability of these vessels to plasma proteins and in highly augmented lymphatic drainage of the extravasated proteins from the renal interstitium. We suggest that in the advanced phase of diabetic nephropathy, proteinuria (corresponding to excess leakage of proteins through the glomerular capillary wall) indicates the probability that postglomerular microvessels have also allowed leakage of plasma proteins. As long as lymphatic drainage is capable of removing the increased quantity of extravasated plasma proteins from the interstitium, renal function should not be deleteriously affected. However, if the excess amount of extravasated proteins exceeds the capacity of lymphatic drainage, increases in interstitial volume and pressure are unavoidable with detrimental consequences for glomerular filtration and tubular reabsorption. Under these conditions, a potential positive-feedback loop can be visualized that involves increased extravasation of plasma proteins leading to increased interstitial pressure that through dilation of the afferent and efferent arterioles results in a further increase in protein extravasation. These conditions combined with glomerular damage should lead to the eventual collapse of renal function.

Sensitive quantitative in vivo techniques were used to assess the permeability at the blood-retinal barrier (BRB) to [14C]sucrose in the anesthetized streptozocin-diabetic rat at various time points (3 wk, 6 mo, 13 mo) after induction of diabetes. The effects of concomitant administration of an aldose reductase inhibitor (ARI) on sorbitol levels in the retina and on BRB permeability were also measured. No increase in BRB permeability was found in rats diabetic for 3 wk or 6 mo, but after 13 mo of hyperglycemia there was an increase in permeability of 240%. No effect on permeability was seen in diabetic animals given the ARI despite the retinal sorbitol levels being decreased in the treated compared with the untreated diabetic group fed a normal diet. This study suggests that the accumulation of sorbitol within the cells of the BRB is not responsible for the breakdown of BRB permeability seen after 7-13 mo of hyperglycemia and that the enzyme aldose reductase is not involved in its pathogenesis.

In diabetes mellitus of long duration almost all capillary regions are severely affected by microangiopathy including peripheral nerves and the retina of the eye, yet there is little damage to brain capillaries. The experiments we report here were aimed at studying in streptozotocin treated rats potential functional changes in the capillaries of the brain after a long period in untreated diabetes. In co-operation with Professor Sue Lightman of the Institute of Ophthalmology, Moorfields Eye Hospital, University of London, we carried out a study lasting over 14 months after streptozotocin administration.

Multiplicity distributions in various rapidity intervals for charged particles produced in collisions of 360 GeV/c protons with aluminium (Al) and gold (Au) targets are presented. The data were analysed separately for the forward and backward hemispheres. Each distribution is well described by a negative binomial distribution. The experimental distributions are compared with the predictions of the multichain model calculated by the Monte Carlo program MCMHA in which the intranuclear cascade process is included, and also with the Lund Monte Carlo FRITIOF. The results of MCMHA reproduce quite well the multiplicity distributions for various rapidity intervals.

A universal description of multiplicity distributions of negative particles is analysed for hA interactions at 40 GeV/c.

Analysing high transverse momentum π− nucleus interactions at 40 GeV/c, a search has been made for the hypothetical dibaryon H0 with strangeness −2, spin-parity 0+ and mass below the two lambda mass. The data came from an experiment performed with a streamer chamber which is well suited to find the H0 through its unique signature of the weak p decay. No H0 event has been found. The 90% confidence upper limit for the observed frequency of production of the H° dibaryon per inelastic π−A collision amounts to 1.5 ·10−4. Cross section upper limits are estimated for C, Cu and Pb targets, also with 90% confidence level. Suche nach dem neutralen Dibaryon mit der Strangeness -2 in π-Kern-Wechselwirkungen bei 40 GeV/c Im Rahmen der Analyse von π− Kern-Wechselwirkungcn bei 40 GeV/e wurde nach dem hypothetischen Dibaryon H° mit Strangeness -2, Spin-Paritat O+ und einem Massenwert unterhalb der ΛΛ-Masse gesucht. Die Datennahme erfolgte mit einer Streamerkammer, die es gestattet, den schwachen Zerfall des H° in ∑-p gut nachzuweisen. Es konnte kein H°-Ereignis gefunden werden. Eine obere Grenze fur die beobachtete Produktionsrate des H°-Dibaryons mit 90% Konfidenz pro inelastischer π−A-Wechselwirkung ist angegeben. Fur die drei unterschiedlichen Targets C, Cu, Pb wurden obere Grenzen des H°-Wirkungsquerschnitts ebenfalls mit 90% Konfidenz abgeschatzt.

Acetylcholine was infused into the aorta of unanesthetized dogs above the origin of the renal arteries. It produced a statistically significant increase in Na, Cl, and K excretion rates and in renal plasma flow with respect to control values in the same experiments and to results obtained in separate control experiments on the same animals. No consistent change was found in glomerular filtration rate, urine flow, and osmolality. In similar experiments Pitressin was also infused. The renal effects of acetylcholine were slightly enhanced by Pitressin. It was concluded that the antidiuretic hormone was not an important mediator in the production of renal effects during acetylcholine infusion. The possible roles of increased medullary blood flow and of increased angiotensin production are discussed.

SummaryAbsorption and transport of cholesterol were studied in rats with gastric and venous cannula. These studies were made on individual experimental animals by periodically sampling the blood of the same animal. Absorption of cholesterol from the intestine depends upon the degree of saturation of the dietary fat available in the intestine. More cholesterol is absorbed when polyunsaturated fat is present than when saturated fat is present in the intestinal lumen. Analyses of individual cholesterol esters in the plasma of rats show a gradual increase in the specific activity (counts per minute per milligram) of the cholesteryl palmitate fraction and to some degree the cholesteryl oleate as a function of time, while, on the other hand, the cholesteryl linoleate and cholesteryl arachidonate showed a gradual decrease in specific activity within a few hours after administration of the radioactive cholesterol. This pattern was observed regardless of whether glyceryl-monostearate, glyceryl-monooleate or glycer...

The anemia developed by rabbits fed a cholesterol-containing diet seems to be of the hemolytic type. A striking increase in reticulocyte count, the appearance of nucleated red cells of different maturity in the peripheral circulation, anisocytosis, anisochromia and erythrocytes with punctate basophilia are characteristic findings on stained films and are the first symptoms of the progressing anemia. The red cell count decreases and reaches the lowest level at about the 8th–12th week of exposure of the animals to cholesterol. Cr51 survival studies revealed a shortened T 1/2:3.7 days compared to 12 days, which is the established normal value under our conditions. The results of cross-transfusion studies are interpreted as the indication that the anemia is developed as the consequence of the production of red cells with decreased resistance.

A simple and specific chromatographic procedure for the quantitative determination of serum vitamin E is presented. Separation of vitamin E is accomplished by glass-fiber paper chromatography. Subsequently, vitamin E levels are estimated by a colorimetric procedure. The method was applied in a series of clinical experiments to illustrate the usefulness of this technique.

The flow of lymph and the mean transit time of tracers between plasma and lymph were measured simultaneously in renal hilar and capsular lymphatics. These measurements were compared under control and experimental conditions. A high correlation was found in the response of hilar and capsular lymph both in terms of lymph flow and tracer transit time. These data provide no evidence for a specific contribution to hilar lymph from the deep region of the medulla.

1. Under specified experimental conditions the distribution space of labelled chylomicrons in the kidney was 13·8 ± 0·9 ml./100 g. tissue. The assumption is supported that this provides a measure for the quantity of intravascular plasma constituents. 2. Values for red blood cells and albumin distribution spaces were 5·2 ± 0·6 and 20·2 ± 1·0 ml./100 g tissue, respectively, in the whole kidney. The ratio of tissue haematocrit over simultaneous arterial haematocrit averaged 0·56. The extravascular albumin fraction amounted to about 31·0% of the total albumin in the whole kidney. 3. A statistically significant correlation was demonstrated between osmotic urine/plasma (U/P) ratios (within the approximate limits of 0·6-1·8) and quantities of extravascular albumin in the medulla.

La permeabilite a l'albumine des vaisseaux capillaires fut caracterisee par le produit PS deRenkin. Cette mesure fut obtenue par une analyse dynamique de la quantite d'albumine contenue dans les interstices de la zone corticale du rein.

The principles of 'central volume' is applied to the sodium and water contents of the inner medullar of the mammalian kidney. The analysis raises questions about the possibility of concentrating sodium ions in the inner medulla by a mechanism that postulates, in the same tissue segment, water withdrawal from the descending thin limb of the loop of Henle and sodium entry from the ascending thin limb.

1. Microangiopathy affects the peritubular capillaries in experimental diabetes. Five to six months after streptozotocin administration to induce experimental diabetes in rats, a progressive increase of lymph flow and of the entry of albumin from the renal peritubular capillaries into the interstitium was seen. 2. Under these conditions, owing to the alteration of peritubular physical forces, the uptake of tubular reabsorbate into the capillaries can be impaired with potentially severe consequences in diabetic nephropathy.

SummaryA series of experiments was undertaken in an attempt to demonstrate the effects of dietary fats on plasma and liver cholesterol concentration in hyper-, eu- and hypothyroid rats. The lowering effect of unsaturated fat on plasma cholesterol seems to be independent of the thyroid state of the animal; that is, regardless of whether the animal is hyper- eu-, or hypothyroid, cholesterol levels of plasma are always lower when animals are fed cottonseed oil than when they are fed the same amounts of butter. In contrast to these effects on plasma, concentration of cholesterol in liver was always higher in animals which were fed unsaturated fat at any of the thyroid states.

Ce travail compare le passage de l'albumine marquee, de l'inuline, et du thiosulfate a partir du lit capillaire dans la lymphe renale capsulaire et hilaire, chez le chien soumis a des diureses salines et aqueuses. Les resultats suggerent que la permeabilite capillaire peritubulaire est influencee de mainiere differente par la variation des conditions de diurese.

On a determine le renouvellement de l'albumine plasmatique dans les interstices du rein. Le temps moyens de passage fut de 37,5 min. Un flux lymphatique de 0,3–0,4 ml par min/100 g tissu renal parut suffisant pour le drainage total de l'albumine interstitiel du rein.

Measurements of the glucose to mannitol tracer concentration ratios in renal venous blood and renal lymph of rats supported the hypothesis that reabsorbed glucose may have direct access to renal lymph by passage through the interstitium.

CHIMAKADZE1,2 has published an interesting report on the treatment with histidine of rabbits fed with cholesterol. He claimed that daily administration of 80 mgm. of histidine for 20 days lowered the serum cholesterol-levels by 1,000–1,300 mgm. per cent and markedly diminished the deposition of aortic lipids. In view of the potential importance of these claims we decided to repeat and extend the experiment.