Effect of fiber entanglement in chopped glass fiber reinforced composite manufactured via long fiber spray-up molding.

Long Fiber Spray-up Molding (LFSM) deviates from the conventional approach in liquid composite molding (LCM) processes by utilizing extremely long chopped strands of fibers as the primary reinforcement material in its fabrication process. In LFSM, chopped fibers are impregnated with resin that is sprayed vertically downwards before reaching the mold surface. The spraying mechanism is mounted on an actuator, which is capable of spraying freely in any specified pattern or direction. Under LFSM, it is extremely difficult to fabricate a composite part with uniformly distributed fiber content throughout its volume. The consequences of the non-uniform fiber volume distribution arise from the fiber entanglement as the length of the fiber reaches up to 100 mm in LFSM. In this study, the effect of fiber entanglement during LFSM was analyzed through various approaches. This included measuring the coefficient of friction between fibers in contact and examining the correlation between fiber lengths and the number of intersections. Furthermore, the viscoelastic properties of the uncured composite part were assessed by experimenting with the influence of viscosity on fiber length during compression molding. The results were then computed, modeled, and visualized in MATLAB, considering variations in viscosity and fiber length, both before and after compression molding.

Interoperable Nanoparticle Sensor Capable of Strain and Vibration Measurement for Rotor Blade Monitoring.

Recent advances in nanomaterials technology create the new possibility to fabricate high performance sensors. However, there has been limitations in terms of multivariate measurable and interoperable sensors. In this study, we fabricated an interoperable silver nanoparticle sensor fabricated by an aerodynamically focused nanomaterial (AFN) printing system which is a direct printing technique for inorganic nanomaterials onto a flexible substrate. The printed sensor exhibited the maximum measurable frequency of 850 Hz, and a gauge factor of 290.62. Using a fabricated sensor, we evaluated the sensing performance and demonstrated the measurement independency of strain and vibration sensing. Furthermore, using the proposed signal separation algorithm based on the Kalman filter, strain and vibration were each measured in real time. Finally, we applied the printed sensor to quadrotor condition monitoring to predict the motion of a quadrotor.

Stretchable Biaxial and Shear Strain Sensors Using Diffractive Structural Colors.

Structural colors that can be changed dynamically, using either plasmonic nanostructures or photonic crystals, are rapidly emerging research areas for stretchable sensors. Despite the wide applications of various techniques to achieve strain-responsive structural colors, important factors in the feasibility of strain sensors-such as their sensing mechanism, stability, and reproducibility-have not yet been explored. Here, we introduce a stretchable, diffractive, color-based wireless strain sensor that can measure strain using the entire visible spectrum, based on an array of cone-shaped nanostructures on the surface of an elastomeric substrate. By stretching or compressing the substrate, the diffractive color can be tuned according to the changing grating pitch. Using the proposed method, we designed three types of strain-sensing modes: large-deformation (maximum 100%) tensile strain, biaxial 2D strain, and shear strain (maximum 78%). The strain sensors were fabricated, and applicability to strain-sensing was evaluated.

Osteopontin Promotes Cell Migration and Invasion, and Inhibits Apoptosis and Autophagy in Colorectal Cancer by activating the p38 MAPK Signaling Pathway.

BACKGROUND: Osteopontin (OPN) is highly expressed in colorectal cancer (CRC) and is associated with disease progression in vivo. High levels of OPN have been demonstrated to predict low survival rates in CRC. Autophagy is a process of self-digestion, which is thought to play a significant role in carcinogenesis. However, the mechanisms of OPN's effects on CRC cell autophagy have not been elucidated. Therefore, we aimed to investigate possible mechanisms of OPN's effects on CRC autophagy. METHODS: HCT116 cell proliferation, apoptosis, and migration and invasion ability were identified by cell counting k¡t-8 assay, flow cytometry, wound healing assay, and transwell chamber invasion assay, respectively. The ratios of proteins LC3-II/LC3-I, P62, and Atg7 were analyzed by Western-blot. Expressions of Beclin-1, Atg4b, Bnip3, and Vps34, both in transcriptional and translational levels, were analyzed and compared by RT-PCR and Western blot. Immunofluorescence and co-focusing experiments were used to investigate the formation of autophagosomes. RESULTS: The results showed that OPN can promote cell proliferation, migration, and invasion, as well as inhibit cell apoptosis. It was also demonstrated that OPN could inhibit cell autophagy. Further experiments revealed that the inhibitory effect of OPN on autophagy could be reversed by blocking the p38 MAPK pathway in HCT116 cells. CONCLUSION: OPN is involved in HCT116 cell progression and is capable of inhibiting cell autophagy possibly by activating the p38 MAPK signaling pathway, implying that OPN could be a potential novel molecular therapeutic biomarker in patients with CRC.

Resting energy expenditure and body composition in patients with newly detected cancer.

BACKGROUND & AIMS: Elevated resting energy expenditure (REE) may be a major determinant in the development of cancer cachexia. The aim of the study was to evaluate REE and body composition in cancer patients and find out the relationship between energy expenditure and substrate utilization. METHODS: Measured resting energy expenditure (mREE), carbohydrate oxidation (C-O), and fat oxidation (F-O) were measured by indirect calorimetry in 714 cancer patients and 642 controls. Extracellular fluid (ECF), intracellular fluid (ICF), and total water (TW) were measured by bioelectrical impedance appliance; fat mass (FM), fat free mass (FFM), and body cell mass (BCM) were further determined. RESULTS: Compared with the controls, cancer patients showed no significant difference in mREE, but had higher mREE/FFM and mREE/pREE. 46.7% (n=333) of cancer patients were hypermetabolic, 43.5% (n=310) normometabolic, and 9.8% (n=71) hypometabolic; whereas 25.2% (n=162) of control subjects were hypermetabolic, 56.5% (n=363) normometabolic, and 18.3% (n=117) hypometabolic. Cancer patients showed an increase in F-O, ECF, TW/BW and ECF/BW; and a decrease in C-O, npRQ, ICF, ICF/BW. REE was correlated to substrate oxidation rate. Cancer patients exhibited an elevation in FM, FM/BW, FFM, and BCM, and a decrease in FFM/BW. CONCLUSIONS: 1. Cancer patients had elevated REE. Cancer type, pathological stage and duration of disease influenced REE. 2. Aberrations in substrate utilization may contribute to the elevated REE in cancer patients. 3. FM, FFM, and BCM diminished in cancer patients, which may be related to the elevated REE.

[Assessment of energy expenditure and body composition in cancer patients].

OBJECTIVE: To demonstrate the changes of resting energy expenditure (REE), substrate metabolism and body composition in cancer patients. METHODS: From September 2004 to March 2008, REE, carbohydrate oxidation (CO) and fat oxidation (FO) in 936 cancer patients and 840 control subjects were measured by indirect calorimetry. Bioelectrical impedance appliance was applied to assess intracellular fluid, extracellular fluid, fat mass (FM) and fat free mass (FFM) in the two groups. RESULTS: No difference in REE was found between the cancer patients and non-cancer patients [(1452.2 +/- 196.4) kcal/d vs. (1429.5 +/- 182.6) kcal/d, P = 0.136]. But REE/FFM and REE/pREE were elevated in cancer patients than in controls (all P < 0.05). Of the cancer patients, 48.6% were hypermetabolic, 42.9% normal and 8.5% hypometabolic, while those were 22.5%, 58.5% and 19.0% in controls. Cancer patients had higher FO [(77.8 +/- 11.3) g/min vs. (67.1 +/- 12.1) g/min, P = 0.000], lower CO and npRQ [(68.7 +/- 10.5) g/min vs. (88.8 +/- 12.1) g/min, P = 0.000; 0.782 +/- 0.012 vs. 0.810 +/- 0.014, P = 0.000]. Cancer patients exhibited lower FM and FFM [(14.9 +/- 4.5) kg vs. (18.4 +/- 5.2) kg, P = 0.000; (44.4 +/- 7.2) kg vs. (46.1 +/- 8.1) kg, P = 0.008]. CONCLUSIONS: Elevated REE is common in cancer patients. Substrate metabolism of the cancer patients features in increased FO, decreased CO and npRQ, which is correlated with the elevated REE. FM and FFM loses in proportion in cancer patients.

[Prevalence of malnutrition in general surgical patients: evaluation of nutritional status and prognosis].

OBJECTIVE: To estimate prevalence of malnutrition on admission to hospital and the relationship between nutritional status and prognosis. METHODS: Four thousand and twelve patients admitted to general surgery department were evaluated by a lot of nutrition indexes within 48 h. Operative morbidity and complications were recorded to identify the difference between malnourished and well-nourished patients. RESULTS: Malnutrition rate of all patients according to BMI, TSF, MAC, AMC, albumin, prealbumin, and lymphocyte count was 21.3%, 50.6%, 20.5%, 21.2%, 24.2%, 35.4% and 55.8%, respectively. The prevalence of malnutrition as defined by SGA and MNA were 38.8% and 20.8%. The older patients (> 60 years old) were associated with a higher prevalence of malnutrition (47.6%) compared with those younger than 60 (31.5%). Malnutrition was more frequently occurred in cancer patients than non-oncologic patients (64.5% vs 22.4%). Patients with digestive tract disease had higher rates of malnutrition than those without digestive tract disease (52.6% vs 30.0%). There were large differences in the morbidity and complications between well nourished patients and malnourished patients (4.0% vs 1.1%, P < 0.01 for morbidity; 19.8% vs 5.9% for complications). CONCLUSIONS: The prevalence of malnutrition in hospitalized surgical patients is high. Malnutrition was associated with increased length of stay, higher operative morbidity and complications.