New chiral I+ complexes for "reagent"-controlled reactions : a combined computational and synthetic approach

Amines are known to form strong complexes with ICl, their potential in organic synthesis is therefore of high interest. Thus chiral complexes with enantiomerically pure amines were investigated by synthetic, spectroscopical and computational means. The complex formed between (R)-1-phenyl-ethylamineA and ICl has been investigated in NMR titrations, which showed the formation of a 1:1 complex and indicated subsequent transformations. These compounds have been investigated experimentally and also have been described by quantum chemical investigations. Furthermore with the aid of ab initio and DFT calculations a chiral complex C, formed by B and ICl could be identi�ed. The charge transfer complex C between (R)-1,2,3,4-tetrahydro-1-naphthylamine B and ICl resembles a chiral electrophile and after a proton-iodine exchange the N-iodo species D is formed. This is supported by time-dependent UV/VIS studies and also NMR titration experiments. If the reaction between B and ICl is continued for two hours, followed by an aequeous workup, the formation of �-tetralone was observed, which is also strongly supporting the conversion of C to D. In the iodolactonisation reaction of 4-phenyl-4-pentenoic acid E to 5-iodomethyl-5-phenyl-dihydrofuran-2-one F, an enantiomeric excess (ee) of 45% was observed. This result was obtained after stirring B and ICl for 30 minutes, bevor the actual lactonisation was performed a

Downregulation of Tumor Necrosis Factor Expression in the Human Mono-Mac-6 Cell Line

Mono-Mac-6 cells, but not U937 cells, can be Induced to rapidly express tumor necrosis factor (TNF) mRNA and protein when triggered with Ilpopolysaccharlde (LPS) at 1 pg/mI. Preincubatlon of the cells for 3 d with low amounts of LPS (10 ng/mI) results In nearly complete suppression of TNF secretion. This downreguiatlon appears to occur at the pretranslational level since specIfIc mRNA is virtually undetectable under these conditions. By contrast, the same prelncubatlon with 10 ng/mI LPS results in enhanced phagocytosls (28.6-67.2% for Staphylococcus aureus), demonstrating that not all monocyte functions are suppressed. While these results show that only stringent exclusion of LPS from culture media allows for Induction of TNF In the Mono-Mac-6 cell line, the pronounced effect of LPS preincubatlon may also provide a suitable model with which to study the mechanisms of LPS-lnduced desensitizatIon

POET: A Self-learning Framework for PROFINET Industrial Operations Behaviour

Since 2010, multiple cyber incidents on industrial infrastructure, such as Stuxnet and CrashOverride, have exposed the vulnerability of Industrial Control Systems (ICS) to cyber threats. The industrial systems are commissioned for longer duration amounting to decades, often resulting in non-compliance to technological advancements in industrial cybersecurity mechanisms. The unavailability of network infrastructure information makes designing the security policies or configuring the cybersecurity countermeasures such as Network Intrusion Detection Systems (NIDS) challenging. An empirical solution is to self-learn the network infrastructure information of an industrial system from its monitored network traffic to make the network transparent for downstream analyses tasks such as anomaly detection. In this work, a Python-based industrial communication paradigm-aware framework, named PROFINET Operations Enumeration and Tracking (POET), that enumerates different industrial operations executed in a deterministic order of a PROFINET-based industrial system is reported. The operation-driving industrial network protocol frames are dissected for enumeration of the operations. For the requirements of capturing the transitions between industrial operations triggered by the communication events, the Finite State Machines (FSM) are modelled to enumerate the PROFINET operations of the device, connection and system. POET extracts the network information from network traffic to instantiate appropriate FSM models (Device, Connection or System) and track the industrial operations. It successfully detects and reports the anomalies triggered by a network attack in a miniaturized PROFINET-based industrial system, executed through valid network protocol exchanges and resulting in invalid PROFINET operation transition for the device

Changing mechanical properties of photopolymerized, dityrosine-crosslinked protein-based hydrogels

Hydrogels based on renewable resources are a promising class of materials for future applications in pharmaceutics, drug delivery and personalized medicine. Thus, optional adjustments of mechanical properties such as swelling behavior, elasticity and network strength are desired. In this context, hydrogels based on the biological raw materials bovine serum albumin and casein were prepared by dityrosine-crosslinking of their tyrosine residues through visible light-induced photopolymerization. Changing the tyrosine accessibility by urea addition before photopolymerization increased the storage modulus of the hydrogels by 650% while simultaneously being more elastic. Furthermore, contributions of the buffer system composition, variation of protein concentration and storage medium towards mechanical properties of the hydrogel such as storage moduli, elasticity, fracture strain, compressive strength and relative weight swelling ratio are discussed. It could be shown, that changes in precursor solution and storage medium characteristics are crucial parameters towards tuning the mechanical properties of protein-based hydrogels

Magnetic Resonance Imaging: Time-DependentWetting and Swelling Behavior of an Auxetic Hydrogel Based on Natural Polymers

A time-dependent understanding of swelling characteristics and external stimuli behavior is crucial for the development and understanding of functional hydrogels. Magnetic resonance imaging (MRI) offers the opportunity to study three-dimensional (3D) soft materials nondestructively. This technique is already widely used as an image-based medical diagnostic tool and is applied here to evaluate complex structures of a hydrogel—a double network of chemically crosslinked casein enhanced with alginate—fabricated by 3D printing. When hydrogel disks immersed in four different liquid systems were analyzed, the material exhibited distinct system-dependent behavior characterized by rheological and mechanical measurements. Further material functionalization was achieved by macroscopic structuring of the hydrogel as an auxetic material based on a re-entrant honeycomb structure. MRI offers the advantage of monitoring overall changes in the area of the analyzed specimen and internal structural changes simultaneously. To assess the behavior of this complex structure, a series of short MRI measurements, each lasting 1.7 min, captured liquid diffusion and thus structural swelling behavior. A clear dependence of external and internal structural changes as a function of liquid properties causing these changes was observed. In conclusion, this approach might pave the way for prospective applications to monitor liquid diffusion into (e.g., vascularization) and swelling behavior of functional hydrogels