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Increasing heat stress caused by anthropogenic climate change may pose a substantial challenge to biodiversity due to associated detrimental effects on survival and reproduction. Therefore, heat tolerance has recently received substantial attention, but its variation throughout ontogeny and effects carried over from one developmental stage to another remained largely neglected. To explore to what extent stress experienced early in life affects later life stages, we here investigate effects of heat stress experienced in the egg stage throughout ontogeny in the tropical butterfly Bicyclus anynana. We found that detrimental effects of heat stress in the egg stage were detectable in hatchlings, larvae and even resulting adults, as evidenced by decreased survival, growth, and body mass. This study shows that even in holometabalous insects with discrete life stages effects of stress experienced early in life are carried over to later stages, substantially reducing subsequent fitness. We argue that such effects need to be considered when trying to forecast species responses to climate change.

We showed in a previous study that a water-nonionic surfactant system, where the surfactant is a 9:1 mixture of tetraethylene glycol monodecyl ether (C(10)E(4)) and pentaethylene glycol monodecyl ether (C(10)E(5)), forms a disconnected lamellar (L(α)) phase. Thus, the isotropic phase spans the whole concentration range from the water-rich L(1) region to the surfactant-rich L(2) region of the phase diagram. The L(1) and L(2) regions are connected via an isotropic channel that separates the two regions of the L(α) phase. In this letter, we monitored the structural evolution of the isotropic phase along a path through this isotropic channel via (1)H NMR self-diffusion measurements. We used this technique because it enables us to distinguish between discrete and bicontinuous structures by comparing the relative self-diffusion coefficients (obstruction factors) D/D(0) of the solvents (i.e. of water and surfactant in the present case). We found that the obstruction factor of water decreases whereas the obstruction factor of the surfactant increases with increasing surfactant concentration and increasing temperature. This trend is interpreted as the transition from a water-continuous L(1) region, which contains discrete micelles, to a bicontinuous structure, which may extend to very high surfactant concentrations. Although there is good evidence of bicontinuity over a broad concentration range, there is no evidence of inverse micelles or any other microstructure at the highest concentration studied in the surfactant-rich L(2) phase.

This paper presents a droplet-based microfluidic platform for miniaturized combinatorial synthesis. As a proof of concept, a library of small molecules for early stage drug screening was produced. We present an efficient strategy for producing a 7 × 3 library of potential thrombin inhibitors that can be utilized for other combinatorial synthesis applications. Picolitre droplets containing the first type of reagent (reagents A(1), A(2), …, A(m)) were formed individually in identical microfluidic chips and then stored off chip with the aid of stabilizing surfactants. These droplets were then mixed to form a library of droplets containing reagents A(1-m), each individually compartmentalized, which was reinjected into a second microfluidic chip and combinatorially fused with picolitre droplets containing the second reagent (reagents B(1), B(2), …, B(n)) that were formed on chip. The concept was demonstrated with a three-component Ugi-type reaction involving an amine (reagents A(1-3)), an aldehyde (reagents B(1-7)), and an isocyanide (held constant), to synthesize a library of small molecules with potential thrombin inhibitory activity. Our technique produced 10(6) droplets of each reaction at a rate of 2.3 kHz. Each droplet had a reaction volume of 3.1 pL, at least six orders of magnitude lower than conventional techniques. The droplets can then be divided into aliquots for different downstream screening applications. In addition to medicinal chemistry applications, this combinatorial droplet-based approach holds great potential for other applications that involve sampling large areas of chemical parameter space with minimal reagent consumption; such an approach could be beneficial when optimizing reaction conditions or performing combinatorial reactions aimed at producing novel materials., (This journal is © The Royal Society of Chemistry 2012)

In classical emulsification processes, surfactants play two roles: first, they reduce the interfacial tension, facilitating droplet deformation and rupture, and second, they reduce droplet coalescence. Here, we use a microfluidic emulsification system to completely uncouple these two processes, allowing stabilization against coalescence to be studied quantitatively and independently of droplet formation. We demonstrate that, in addition to the classical effect of stabilization by an increase of surfactant concentration, the dynamics of adsorption of surfactant at the water-oil interface is a key element for droplet stabilization. Microfluidic emulsification devices can therefore be tailored to improve emulsification while decreasing the concentration of surfactant by increasing the time before the droplets first come into contact.

We studied the stratification behavior of free-standing foam films which are stabilized by nonionic surfactants and contain polyelectrolytes with different backbone flexibilities, namely sulfonated polyacrylamide (PAMPS), carboxymethyl-chitin (CM-Chitin), Xanthan, and DNA. Stratification is due to a specific arrangement of the polymer chains in the confined environment of the thin films. While stratification is easily observed for films containing PAMPS and CM-Chitin, it is more difficult to observe with Xanthan and DNA. We will discuss this effect in terms of different polymer backbone rigidities, which, in turn, are expected to lead to different time scales for polymer network relaxation.

The antimicrobial activity of poly(2-methyl-1,3-oxazoline)s (PMOX) with the antimicrobial N,N-dimethyldodecylammonium (DDA) end group is greatly dependent on the nature of the group at the distal end of the polymer, the satellite group. Three comparable PMOX with a DDA end group and different satellite groups (methyl, decyl, hexadecyl) were investigated with respect to the reasons for the huge differences in their biocidal behavior. Static light scattering (SLS) and pulsed field gradient diffusion NMR measurements revealed that the samples show comparable aggregation conduct, thus, not being responsible for the varying biological activity. Experiments using different liposomal systems as models for bacterial cell membranes have been performed. It was found that differential interactions between the respective polymers and the phospholipid membranes constitute the reason for the varying effectiveness observed in antimicrobial susceptibility determinations.

Ligatures of the supracardiac lymph vessels and the cardiac lymph nodes have been performed in fifty mongrel dogs. Comparative electrocardiographical, light microscopical, scanning and transmission electron microscopical investigations were done one day to three months after surgery. The demonstrated findings confirmed former results concerning the topography and the microstructure of the cardiac lymph vascular drainage system. In addition, the comparative functional and morphological examinations made evident the pathogenetic importance of cardiac lymphostasis. Lymphostatic oedema has been discussed as a pathogenetic co-factor for human heart diseases. Therapeutic attempts on experimental cardiac lymphostasis with i.v. - application of Coumarin-Troxerutin were without effect.

In a series of 342 arterial reconstructions of the iliacolic to popliteal arteries 24 patients with lymph vessel damage were observed. The diagnosis of lymphedema was established in 18 patients by clinical findings and in 2 of them the diagnosis was confirmed by lymphography with followup of 1 year. Three patients developed an internal lymphogenic cyst, 3 showed an external lymph fistula, and 1 patient developed an infection of a dacron bifurcation graft. The infection occurred when an additional occlusion of the left femoral artery was bypassed with an autologous saphenous vein graft and a lymph cyst in the groin, which was excised several times, became infected. The patient was treated successfully by excising the graft and performing an axillofemoral bypass. Although cases of surgical damage to lymph vessels following arterial reconstructions are rare in the literature, it is assumed that this complication occurs more often than reported, because of lack of lymphographic information.

Increased blood and plasma viscosity was found in patients with chronic arterial occlusion in comparison with healthy probands. The measurements were done at high and low shear rates. Parenteral pentoxifylline (Trental) lowered blood and plasma viscosity of patients significantly, especially when measured at low shear rates. Application of bencyclane (Fludilat) produced variable results. A definite connection between rheological changes and alterations of the protein fractions in plasma could not be established.

Acquired arteriovenous fistulas should be surgically cured as soon as possible after the diagnosis. In all the patients we treated, the arteriovenous fistula had existed for quite a long time, i.e. up to 26 years. These arteriovenous fistulas were surgically closed by the separation-method, the resection of the vessels and vascular reconstruction, or by the transvenous technique. - Arteriovenous fistulas, which have been in existence for quite a long time, result in cardiac dilatation, which can be cured after closure of the arteriovenous fistula. Furthermore, there can be pathologic changes of the vein and artery wall: chronic venous insufficiency and arterial ectasia can result. - After closure of the arteriovenous fistula our patients no longer complained of venous reflux disturbances. Even after closure of the arteriovenous fistula, an arterial ectasia is not reversible. The reasons for this are discussed. Symptoms, which occur after the closure of an arteriovenous fistula, which had existed for a long period and had produced a severe arterial ectasia, are looked upon as an autonomous disease. During the progress of this disease many complications can occur, even the rupture of the ectatic artery. The question is therefore discussed, whether it is justified to resect the ectatic arterial segment together with the arteriovenous fistula and to implant an alloplastic vascular graft in its place during the initial operation.