The influence of lateral forces on the cell stiffness measurement by optical tweezers vertical indentation

We studied the lateral forces arising during the vertical indentation of the cell membrane by an optically trapped microbead, using back focal plane interferometry to determine force components in all directions. We analyzed the cell-microbead interaction and showed that indeed the force had also lateral components. Using the Hertz model, we calculated and compared the elastic moduli resulting from the total and vertical forces, showing that the differences are important and the total force should be considered. To confirm our results we analyzed cells from two breast cancer cell lines: MDA-MB-231 and HBL-100, known to have different cancer aggressiveness and hence stiffness.     

Antimicrobial effect of an Undaria pinnatifida composite film containing vanillin against Escherichia coli and its application in the packaging of smoked chicken breast

To develop a value‐added product, we used the under‐utilised seaweed Undaria pinnatifida as a source material for the fabrication of a biodegradable film by extracting U. pinnatifida protein (UPP). UPP/gelatine composite films with different constituent ratios were prepared. In addition, the UPP/gelatine composite films containing vanillin (0.05%, 0.1% and 0.5%) were prepared as antimicrobial packaging material. To evaluate the utility of the UPP composite film containing 0.5% vanillin as food packaging material, smoked chicken breast samples inoculated with Escherichia coli were packed with the film and stored at 4 °C for 10 days. It was observed that packaging of smoked chicken breast with the UPP composite film containing vanillin decreased the population of the inoculated E. coli by 1.12 log CFU g^?1 compared with that in the control sample. Thus, the UPP/gelatine composite film with added vanillin can be utilised as a packaging material for smoked chicken breast.     

In vitro culture of Boletus badius as a source of indole compounds and zinc released in artificial digestive juices

Food Science and Biotechnology - The objective of this study was to obtain the in vitro cultures of Boletus badius under controlled conditions and investigate the release of indole compounds and...     

Ahdeb油田水平井控水完井及一体化耦合模型

Ahdeb油田上部主力层系采用水平井注采井网开发，前期取得了较好开发效果，但开发过程中部分井组稳产与高含水矛盾日益突出，亟需开展水平井调流控水研究。针对Ahdeb油田这类边水或注入水在高渗层或断层裂缝带突窜引起的水平井见水，基于不同钻遇储层特征，形成了水平井控水完井分类治理方案，并建立了一套同时适用于盲筛分段组合、中心管和ICD控水完井工艺的井筒-油藏一体化耦合数值模型。该模型重点考虑了水平井筒受多种作用力下的变质量流动过程，提高了单井的模拟和实际含水率匹配度。研究表明：对于根部见水的水平井，ICD完井及中心管完井均有较好控水效果，含水率从49.8%分别下降至37.8%和35.0%。完井控水装置的限流范围应略大于出水井段，才能有效控制含水率。调流控水装置下入时机应选择在水平井见水前，能够最大程度降低整个生产过程中的含水率，从而提高单井累产油量。     

Entropy‐Based Optimal Sensor Placement for Model Identification of Periodic Structures Endowed with Bolted Joints

The number of sensors and the corresponding locations are very important for the information content obtained from the measured data, which is a recognized challenging problem for large‐scale structural systems. This article pays special attention to the sensor placement issues on a large‐scale periodically articulated structure representing typical pipelines to extract the most information from measured data for the purpose of model identification. The minimal model parameter estimation uncertainties quantified by the information entropy (IE) measure is taken as the optimality criterion for sensors placement. By utilizing the inherent periodicity property of this type of structure together with the Bloch theorem, a novel tailor‐made modeling approach is proposed and the computational cost required for dynamic analysis to form the IE with respect to the entire periodic structure can be dramatically reduced regardless of the number of contained periodic units. In addition, to avoid the error of dynamic modeling induced by conventional finite element method based on static shape function, the spectral element method, a highly accurate dynamic modeling method, is employed for modeling the periodic unit. Moreover, a novel discrete optimization method is developed, which is very efficient in terms of the number of function evaluations. The proposed methodology is demonstrated by both numerical and laboratory experiments conducted for a bolt‐connected periodic beam model.     

SPHERES, Jülich's high-flux neutron backscattering spectrometer at FRM II

SPHERES is a third-generation neutron backscattering spectrometer, located at the 20 MW German neutron source FRM II and operated by the Ju?lich Centre for Neutron Science. It offers an energy resolution (fwhm) better than 0.65 μeV, a dynamic range of ±?31 μeV, and a signal-to-noise ratio of up to 1750:1.     

How important is tryptophan in human health?

Tryptophan (Trp) is an amino acid and an essential component of the human diet. It plays a crucial role in many metabolic functions. Clinicians can use Trp levels in the course of diagnosing various metabolic disorders and the symptoms associated with those diseases. Furthermore, supplementation with this amino acid is considered in the treatment of depression and sleep disorders, mainly due to the Trp relationship with the synthesis of serotonin (5-HT) and melatonin. It is also used in helping to resolve cognitive disorders, anxiety, or neurodegenerative diseases. Reduced secretion of serotonin is associated with autism spectrum disorder, obesity, anorexia and bulimia nervosa, and other diseases presenting peripherals symptoms. The literature strongly suggests that Trp has a significant role in the correct functionality of the brain-gut axis and immunology. This information leads to the consideration of Trp as an essential dietary component due to its role in the serotonin pathway. A reduced availability of Trp in diet and nutraceutical supplementation should be considered with greater concern than one might expect. This paper constitutes a review of the more salient aspects gleaned from the current knowledge base about the role of Trp in diseases, associated nutritional disorders, and food science, in general.