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Crimp frequency during the stuffer box crimping process is of great importance for controlling morphology of crimped fibers. A fiber is considered as a viscoelastic rheological fluid, and an approximate formulation for crimp frequency is obtained revealing the main factors affecting the crimping process. [ABSTRACT FROM AUTHOR]

The fractal harmonic law admits that the friction between the pure water and the moving surface is the minimum when fractal dimensions of water in Angstrom scale are equal to fractal dimensions of the moving surface in micro scale. In the paper, the fractal harmonic law is applied to demonstrate the mechanism of waterproof/ dustproof. The waterproof phenomenon of goose feathers and lotus leaves is illustrated to verify our results and experimental results agree well with our theoretical analysis. [ABSTRACT FROM AUTHOR]

This paper finds that a polymer liquid membrane can be effectively used for nanomaterials fabrication using a blowing air and an electronic force. Polyvinyl alcohol solution is used to produce membrane on a rotating ring, which passes through periodically the solution, the membrane is deformed into a bubble by the blowing air under the presence of an electrostatic field. The experimental data show that the receptor distance affects the fiber size greatly. [ABSTRACT FROM AUTHOR]

Fabrication of crimped fibers has been caught much attention recently due to remarkable improvement surface-to-volume ratio. The precise mechanism of the fiber crimp is, however, rare and preliminary. This paper finds that pulsation of fibers is the key factor for fiber crimp, and its configuration (wave formation) corresponds to its nature frequency after solidification. Crimping performance can be improved by temperature control of the uncrimped fibers. In the paper, polylactide/ dimethylfomamide solution is fabricated into crimped nanofibers by the bubble electrospinning, an approximate period- amplitude relationship of the wave formation is obtained. [ABSTRACT FROM AUTHOR]

Frictional force is a vitally important factor in the application of engineering either in macroscopic contacts or in micro/nanoscale contacts. Understanding of the influencing factors about frictional force is essential for the design of miniaturized devices and the use of minimal friction force. In the paper, dimensional analysis is used to analysis factors relative to frictional force. We show that the frictional force scales with Aa1N1-a1 where A is the contact area and N is the normal contact force. An experiment is carried out to verify the new friction law. [ABSTRACT FROM AUTHOR]

Decreasing friction force between a swimming suit and water is the key factor to design swimming suits. Water continuum mechanics forbids discontinuous fluids, but in angstrom scale water is indeed discontinuous. Swimming suit is smooth on large scale, but it is discontinuous when the scale becomes smaller. If fractal dimensions of swimming suit and water are the same, a minimum of friction force is predicted, which means fractal harmonization. In the paper, fractal harmonic law is introduced to design a swimsuit whose surface fractal dimensions on a macroscopic scale should be equal to or closed to the water's fractal dimensions on an Angstrom scale. Various possible microstructures of fabric are analyzed and a method to obtain perfect fractal structure of fabric is proposed by spraying nanofibers to its surface. The fractal harmonic law can be used to design a moving surface with a minimal friction. [ABSTRACT FROM AUTHOR]

Here we show an intriguing phenomenon in the bubble electrospinning process that the ruptured film might be stripped upwards by an electronic force to form a very thin and long plate-like strip, which might been received in the metal receiver as discontinuous backbone-like wrinkled materials, rather than smooth nano-fibers or microspheres. The processes are called the bubble electrospinning. The electronic force can be replaced by a blowing air, and the process is called as the blown bubble spinning. We demonstrate that the size and thickness of the ruptured film are the crucial parameters that are necessary to understand the various observations including beads and nanoporous materials. We identify the conditions required for a ruptured film to form discontinuous structure, and a critical width of the ruptured film to form a cylindrical fiber, above which a long and thin plate-like strip might be obtained, and a criterion for oscillatory jet diameter, which leads to bead morphology of the obtained fibers. The space of the adjacent beads depends on the fiber size. We anticipate our assay to be a starting point for more sophisticated study of the bubble electrospinning and the blown bubble spinning and for mass-production of both nanofibers and nanoscale discontinuous materials. [ABSTRACT FROM AUTHOR]

Based on the analysis of relevant literature studies on psychology and emotional labor, the paper develops a theoretical model of emotional labor of tour guides in East China itinerary by applying the theory and method of SEM, combining the characteristics of the management of tour guide human resources and makes an in-depth discussion and analysis of the essential connotation of emotional labor of tour guides, its moderating factors and consequence variables. The study results indicate that the relationship of different variables in SEM fully accords with the hypotheses. The study fills the gap in this area to a certain degree and also offers some practical suggestions regarding better integrating emotional labor management in the human resources management of tour guides. [ABSTRACT FROM AUTHOR]

The nuclear matrix-intermediate filament system of human neuroblastoma SK-N-SH cells before and after retinoic acid (RA) treatment was selectively extracted and the distribution of prohibitin (PHB) in the nuclear matrix, as well as its colocalization with related genes, was observed. Results of two-dimensional gel electrophoresis (2-DE), mass spectrometry (MS) identification, and protein immunoblotting all confirm that PHB was present in the components of SK-N-SH nuclear matrix proteins and was down-regulated after RA treatment. Immunofluorescence microscopy observations show that PHB was localized in the nuclear matrix and its distribution was altered due to RA treatment. Laser confocal microscopy results reveal that PHB colocalized with the expression products of c-myc, c-fos, p53, and Rb, but the colocalization region was altered after RA treatment. Our results prove that PHB is a nuclear matrix protein and is localized in nuclear matrix fibers. The distribution of PHB in SK-N-SH cells and its colocalization with related proto-oncogenes and tumor suppressor genes suggest that PHB plays pivotal roles in the differentiation of SK-N-SH cells and deserves further study. [ABSTRACT FROM AUTHOR]

Nuclear-matrix proteins can be proteomic markers for cancer lesions. The present study aimed to determine the roles of heterogeneous nuclear ribonucleoproteins-A2 and B1 (hnRNP-A2/B1) in human gastric carcinogenesis. Human gastric cancer and non-cancerous tissues were collected for immunohistochemical analysis. Proteomics technique, Western blot, laser confocal microscope, and real-time quantitative reverse transcription-polymerase chain reaction were performed to determine the aberrant expression of nuclear-matrix proteins. hnRNP-A2/B1 existed in the nuclear matrix of gastric cancer cells, and its expression was enhanced in human gastric cancer and decreased by hexamethylene bisacetamide. The colocalization of hnRNP-A2/B1 with c-myc, c-fos, p53, and Rb was translocated from the nucleolus to the cytoplasm during the differentiation of tumor cells. hnRNP-A2/B1 affected tumor cell differentiation through interaction with oncogenes and tumor-suppressor genes, and it was overexpressed in human gastric cancer. We postulate that hnRNP-A2/B1 could serve as a biomarker for the diagnosis of human gastric cancer. [ABSTRACT FROM AUTHOR]

Relationships between hyperhomocysteinemia (HHE) and neurodegenerative diseases have been widely studied. However, the impact of serum total homocysteine (tHcy) levels on cognitive function has not been confirmed. C677T polymorphisms in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene have impacts on tHcy level; it is suspected to influence cognitive function, but only few investigations have assessed its effects on non-dementia adults and the results have been controversial. Moreover, there is no report about Chinese subjects. In the present study, we determined C677T/MTHFR genotype, serum tHcy concentration and cognition in 182 nondemented subjects aged 55–88 years to probe the associations between MTHFRC677T mutation, increased tHcy levels and decreased cognitive function in a northern city in China. A serum tHcy level ≥ 16 μmol/l was deemed HHE. Cognitive function was assessed by the Mini Mental State Examination (MMSE) and Basic Cognitive Aptitude Tests (BCAT). Results showed that: (i) subjects with the T allele had higher serum tHcy levels than those without, especially in lower folate status; (ii) T allele and CT/TT genotype frequencies in subjects with HHE were higher than in non-HHE subjects (P < 0.05); and (iii) serum tHcy level was inversely related to total BCAT score (P < 0.05) but MTHFR677 C to T polymorphism had no association with it. Our results confirmed that the MTHFR 677 C to T mutation, especially in lower serum folate concentration status, results in the increase of serum tHcy levels which is bad for cognitive function and indicates that higher serum folate level is of benefit in keeping lower serum tHcy level and better cognitive function. The results provide some valuable clues for individualized nutrition intervention of HHE and cognition decline in the middle-aged and the elderly. [ABSTRACT FROM AUTHOR]

Hairs of a polar bear (Ursus maritimus) are of superior properties such as the excellent thermal protection. Why do polar bears can resist such cold environment? The paper concludes that its fractal porosity plays an important role, and its fractal dimensions are very close to the golden mean, 1.618, revealing the possible optimal structure of polar bear hair. [ABSTRACT FROM AUTHOR]

Superthin polyvinil alcohol graphene sheet of several nanometers in thickness is obtained by the electrospinning. Polyvinil alcohol (10 wt.%) solution with the additive of ash (0.5 wt.%) is used for this purpose. [ABSTRACT FROM AUTHOR]