G?rungserscheinungen

Ohne Zusammenfassung     

Processing and analytical characterisation of pulp-enriched cloudy apple juices

Pulp-enriched cloudy apple juices were manufactured from two apple varieties by blending of apple puree with natural cloudy apple juice in order to enrich bioactive secondary plant substances. Finishing of the puree with a 0.6-mm mesh screen and final product homogenisation revealed as the optimum processing technology for the novel 100% fruit beverage. The presence of large particles originating from the puree prevented long-term cloud stability, but due to the proportion of cloud-stable juice a complete phase separation did not occur. Optimal drinkability was achieved at a viscosity of 11.5 mPa s. Polyphenol compositions and concentrations were determined by means of RP-HPLC/PDA. The results ranged from 109 to 610 mg/l. All samples showed the typical polyphenol pattern of apples with dominating hydroxycinnamic acids followed by flavanols and flavonols. The puree addition to the cloudy apple juices increased the polyphenol concentrations by average 100%. Relatively, the highest increase could be observed for dimeric procyanidins. Different technological variants did not affect significantly the polyphenol concentrations. The dietary fibre contents of the pulp-enriched cloudy apple juices ranged from 5.8 to 9.4 g/l.     

Efficient random subcloning of DNA sheared in a recirculating point-sink flow system

Based on a high-performance liquid chromatographic pump, we have built a device that allows recirculation of DNA through a 63-microm orifice with ensuing fractionation to a minimum fragment size of approximately 300 base pairs. Residence time of the DNA fragments in the converging flow created by a sudden contraction was found to be sufficiently long to allow extension of the DNA molecules into a highly extended conformation and, hence, breakage to occur at midpoint. In most instances, 30 passages sufficed to obtain a narrow size distribution, with >90% of the fragments lying within a 2-fold size distribution. The shear rate required to achieve breakage was found to be inversely proportional to the 1.0 power of the molecular weight. Compared with a restriction digest, up to 40% of all fragments could be cloned directly, with only marginal improvements in cloning efficiency having been observed upon prior end repair with Klenow, T4 polymerase or T4 polynucleotide kinase. Sequencing revealed a fairly random distribution of the fragments.     

Post-concussive symptoms in children with mild traumatic brain injury.

To investigate postconcussive symptoms (PCS) following pediatric mild traumatic brain injury (mTBI), 8- to 15-year-old children with mTBI (n = 186) and a comparison group with uncomplicated orthopedic injuries (OI, n = 99) were recruited from two emergency departments. Parent and child ratings of PCS and symptom counts were obtained within 3 weeks after injury (baseline) and at 1, 3, and 12 months postinjury. The mTBI group also completed magnetic resonance imaging at baseline. Group differences were examined using growth modeling, controlling for age at injury, sex, socioeconomic status, and (for parent-based measures) preinjury symptom levels. Relative to the OI group, the mTBI group had higher ratings of somatic PCS and parent counts of PCS at the initial assessments, but higher parent ratings of cognitive PCS and child counts of PCS throughout follow-up. Higher levels of PCS in the mTBI group were associated with motor-vehicle-related trauma, loss of consciousness, neuroimaging abnormalities, and hospitalization. The findings validate both transient and persistent PCS in children with mTBI and document associations of symptoms with injury and noninjury factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-intensity x-ray diffraction apparatus for pressures up to 100 kilobars and temperatures down to 1.5 K

A high-pressure diamond anvil pressure technique for x-ray structure investigations at temperatures down to 1.5 K is described. An energy dispersive method in conjunction with a newly developed conical x-ray shutter brings maximum intensity to the adjacent germanium detector. Superconductivity is detected by use of a SQUID. The 4096-channel analyzer data are evaluated on-line by a computer. The precision of the lattice parameter determination is discussed.     

Identification of Entry Inhibitors against Delta and Omicron Variants of SARS-CoV-2

Entry inhibitors against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are urgently needed to control the outbreak of coronavirus disease 2019 (COVID-19). This study developed a robust and straightforward assay that detected the molecular interaction between the receptor-binding domain (RBD) of viral spike protein and the angiotensin-converting enzyme 2 (ACE2) receptor in just 10 min. A drug library of 1068 approved compounds was used to screen for SARS-CoV2 entry inhibition, and 9 active drugs were identified as specific pseudovirus entry inhibitors. A plaque reduction neutralization test using authentic SARS-CoV-2 virus in Vero E6 cells confirmed that 2 of these drugs (Etravirine and Dolutegravir) significantly inhibited the infection of SARS-CoV-2. With molecular docking, we showed that both Etravirine and Dolutegravir are preferentially bound to primary ACE2-interacting residues on the RBD domain, implying that these two drug blocks may prohibit the viral attachment of SARS-CoV-2. We compared the neutralizing activities of these entry inhibitors against different pseudoviruses carrying spike proteins from alpha, beta, gamma, and delta variants. Both Etravirine and Dolutegravir showed similar neutralizing activities against different variants, with EC50 values between 4.5 to 5.8 nM for Etravirine and 10.2 to 22.9 nM for Dolutegravir. These data implied that Etravirine and Dolutegravir may serve as general spike inhibitors against dominant viral variants of SARS-CoV-2.     

Biodegradability of biomass pyrolysis oils: Comparison to conventional petroleum fuels and alternatives fuels in current use

Concern with environmental issues such as global climate change has stimulated research into the development of more environmentally friendly technologies and energy sources. One critical area of our economy is liquid fuels. Fast pyrolysis of lignocellulosic biomass for liquids production is of particular concern, as it is one of the most interesting ways to produce renewable liquid fuel for transport and heat and power production.The aerobic biodegradability of various pyrolysis oils from different origins and of a EN 590 diesel sample was examined using the Modified Sturm (OECD 301B). The results demonstrate that all fast pyrolysis oils assessed are biodegradable with similar shaped curves with 41–50% biodegradation after 28 days, whereas the diesel sample reached only 24% biodegradation. Since pyrolysis oils achieved biodegradability over 20% these are classified as inherently biodegradable. Modelling of biodegradation processes was successfully performed with a first-order chemical reaction.The biodegradability results obtained for biomass pyrolysis oils are compared to those of conventional and alternative fuels.     

Zum Mechanismus der thermischen Abspaltung von Chlorwasserstoff aus Polyvinylchlorid. 9. mitt.: Zur struktur der verzweigungen in polyvinylchlorid

The reduction of PVC and of copolymers from vinyl chloride and 2-chloropropene with lithium aluminium hydride occurs in a nearly quantitative manner. A selective reduction of the tertiary chlorine atoms in the copolymers, using lithium deuteride, cannot be observed by means of n.m.r. spectroscopy. The amount of CH₃-groupins the reduced samples was determined by i.r. spectroscopic compensation against polymethylene. The number of methyl groups determined in the copolymers agrees well with the copolymer composition found by n.m.r. spectroscopy. The experimental results of the determination of branches and of the thermal degradation indicate no tertiary chlorine atoms in PVC; therefore, one can assume another structure of branches in PVC.     

The preparation and characterization of the methoxy derivatives of polyunsaturated fatty acids: Stabilized product analogs of lipoxygenase catalysis

The products from the action of soybean lipoxygenase on a series of polyunsaturated fatty acids have been converted in 2 steps into the corresponding methoxy derivatives. The product hydroperoxides were reduced in situ to alcohols with sodium borohydride. The ethers were generated by treatment of the alcohols with sodium hydride and methyl iodide in tetrahydrofuran. 13-Methoxy-9(Z),11(E)-octadecadienoic, 15-methoxy-11(Z),13(E)-eicosadienoic and 15-methoxy-5(Z),8(Z),11(Z), 13(E)-eicosatetraenoic acids were thus prepared. The methyl ethers were analyzed and the structures established by high performance liquid chromatography, nuclear magnetic resonance and infrared spectrometry, polarimetry and mass spectroscopy (as methyl esters). The methylation reaction proceeds without molecular rearrangements or racemiziation.