Quasi-1D Conductive Network Composites for Ultra-Sensitive Strain Sensing.

Highly performance flexible strain sensor is a crucial component for wearable devices, human-machine interfaces, and e-skins. However, the sensitivity of the strain sensor is highly limited by the strain range for large destruction of the conductive network. Here the quasi-1D conductive network (QCN) is proposed for the design of an ultra-sensitive strain sensor. The orientation of the conductive particles can effectively reduce the number of redundant percolative pathways in the conductive composites. The maximum sensitivity will reach the upper limit when the whole composite remains only "one" percolation pathway. Besides, the QCN structure can also confine the tunnel electron spread through the rigid inclusions which significantly enlarges the strain-resistance effect along the tensile direction. The strain sensor exhibits state-of-art performance including large gauge factor (862227), fast response time (24 ms), good durability (cycled 1000 times), and multi-mechanical sensing ability (compression, bending, shearing, air flow vibration, etc.). Finally, the QCN sensor can be exploited to realize the human-machine interface (HMI) application of acoustic signal recognition (instrument calibration) and spectrum restoration (voice parsing).

Highly Sensitive Pressure Sensor Based on Elastic Conductive Microspheres.

Elastic pressure sensors play a crucial role in the digital economy, such as in health care systems and human-machine interfacing. However, the low sensitivity of these sensors restricts their further development and wider application prospects. This issue can be resolved by introducing microstructures in flexible pressure-sensitive materials as a common method to improve their sensitivity. However, complex processes limit such strategies. Herein, a cost-effective and simple process was developed for manufacturing surface microstructures of flexible pressure-sensitive films. The strategy involved the combination of MXene-single-walled carbon nanotubes (SWCNT) with mass-produced Polydimethylsiloxane (PDMS) microspheres to form advanced microstructures. Next, the conductive silica gel films with pitted microstructures were obtained through a 3D-printed mold as flexible electrodes, and assembled into flexible resistive pressure sensors. The sensor exhibited a sensitivity reaching 2.6 kPa-1 with a short response time of 56 ms and a detection limit of 5.1 Pa. The sensor also displayed good cyclic stability and time stability, offering promising features for human health monitoring applications.

Structural Design and DLP 3D Printing Preparation of High Strain Stable Flexible Pressure Sensors.

Flexible pressure sensors are crucial force-sensitive devices in wearable electronics, robotics, and other fields due to their stretchability, high sensitivity, and easy integration. However, a limitation of existing pressure sensors is their reduced sensing accuracy when subjected to stretching. This study addresses this issue by adopting finite element simulation optimization, using digital light processing (DLP) 3D printing technology to design and fabricate the force-sensitive structure of flexible pressure sensors. This is the first systematic study of how force-sensitive structures enhance tensile strain stability of flexible resistive pressure sensors. 18 types of force-sensitive structures have been investigated by finite element design, simultaneously, the modulus of the force-sensitive structure is also a critical consideration as it exerts a significant influence on the overall tensile stability of the sensor. Based on simulation results, a well-designed and highly stretch-stable flexible resistive pressure sensor has been fabricated which exhibits a resistance change rate of 0.76% and pressure sensitivity change rate of 0.22% when subjected to strains ranging from no tensile strain to 20% tensile strain, demonstrating extremely low stretching response characteristics. This study presents innovative solutions for designing and fabricating flexible resistive pressure sensors that maintain stable sensing performance even under stretch conditions.

Riemannian Surface on Carbon Anodes Enables Li-Ion Storage at -35 °C.

Since sluggish Li+ desolvation leads to severe capacity degradation of carbon anodes at subzero temperatures, it is urgently desired to modulate electron configurations of surface carbon atoms toward high capacity for Li-ion batteries. Herein, a carbon-based anode material (O-DF) was strategically synthesized to construct the Riemannian surface with a positive curvature, which exhibits a high reversible capacity of 624 mAh g-1 with an 85.9% capacity retention at 0.1 A g-1 as the temperature drops to -20 °C. Even if the temperature drops to -35 °C, the reversible capacity is still effectively retained at 160 mAh g-1 after 200 cycles. Various characterizations and theoretical calculations reveal that the Riemannian surface effectively tunes the low-temperature sluggish Li+ desolvation of the interfacial chemistry via locally accumulated charges of non-coplanar sp x (2 < x < 3) hybridized orbitals to reduce the rate-determining step of the energy barrier for the charge-transfer process. Ex-situ measurements further confirm that the sp x -hybridized orbitals of the pentagonal defect sites should denote more negative charges to solvated Li+ adsorbed on the Riemannian surface to form stronger Li-C coordinate bonds for Li+ desolvation, which not only enhances Li-adsorption on the curved surface but also results in more Li+ insertion in an extremely cold environment.

Characterization of different non-Saccharomyces yeasts via mono-fermentation to produce polyphenol-enriched and fragrant kiwi wine.

To improve the functional property and flavor quality of kiwi wine, the performance of 11 strains of non-Saccharomyces yeasts from 5 species were comprehensively characterized in kiwi wine. Chemical compositions and sensorial profiles of all kiwi wines were assessed. The results indicated that most non-Saccharomyces cerevisiae produced more polyphenols than Saccharomyces cerevisiae WLS21 (Sc21). A total of 130 volatiles were observed in the kiwi wines. Zygosaccharomyces rouxii IFO30 (Zr30), Zygosaccharomyces bailii IFO37 (Zb37) and Schizosaccharomyces pombe 1757 (Sp57) were found to produce more concentration of volatile compounds than the other strains including Sc21. 25 volatiles with a rOAV ≥0.1 were identified. Principal component analysis (PCA) revealed that Zr30 and Zb37 specifically increased the concentrations of ethyl esters, 2-methylbutan-1-ol and phenethyl acetate, while Sp57 primarily enhanced the contents of phenylacetaldehyde, 2-methylbutan-1-ol and phenethyl acetate. The sensory analysis demonstrated that Zr30 and Zb37 strains were more optimal than S. cerevisiae in aroma generation. In addition, the partial least-squares regression (PLSR) analysis revealed that tropical fruits, red fruits, dried fruits, flowers and floral odors showed an intensely positive impact on the overall acceptability of the kiwi wine.

Assessment of chemical constitution and aroma properties of kiwi wines obtained from pure and mixed fermentation with Wickerhamomyces anomalus and Saccharomyces cerevisiae.

BACKGROUND: To improve the aroma of kiwi wine through the utilization of Wickerhamomyces anomalus, kiwi juice was fermented using a selected W. anomalus strain in pure culture and mixed fermentations with Saccharomyces cerevisiae, which was inoculated simultaneously and sequentially. The physicochemical indices, volatile compounds and aroma properties of the kiwi wines were assessed. RESULTS: The study suggested that the ethanol, color indices and organic acids of the wines were closely related to the method of inoculation. Compared with the pure S. cerevisiae fermentation, the mixed fermentations produced more varieties and concentrations of volatiles. The sequential fermentations increased the concentrations of esters and terpenes, improving the flower and sweet fruit notes of the wines. The simultaneous inoculation enhanced the contents of esters and aldehydes, intensifying the flower, sweet and sour fruit of the wines. Partial least-squares regression analysis showed that esters and terpenes contributed greatly to the flower and sweet fruit aroma, whereas aldehydes were the major contributors to the sour note. CONCLUSION: Based on our results, the mixed fermentations not only enriched the types and concentrations of volatiles, but also had better sensory properties. © 2021 Society of Chemical Industry.

Corrigendum to "Excretory Function of Intestinal Tract Enhanced in Kidney Impaired Rats Caused by Adenine".

[This corrects the article DOI: 10.1155/2016/2695718.].

A Self-Healable Bifunctional Electronic Skin.

For the mimicry of human skin, one of the challenges is how to detect and recognize different stimulus by electronic device, while still has the ability of skin self-recovery at the same time. Because of the excellent elasticity and flexibility, strong self-healing ability, in this paper, we reported a bifunctional self-healing e-skin with polyurethane (PU) and polyurethane@multiwalled carbon nanotubes (PU@CNT) as the sensing materials by integrating a resistance temperature sensor on top of a capacitive pressure sensor on the same flexible cellulose nanocrystals@carboxylated nitrile rubber@polyethylenimine (CNC@XNBR) substrate. Studies found that each type of sensor exhibited fast and superior response to only the target stimuli. Meanwhile, due to the self-recovery properties of PU and CNC@XNBR, as-fabricated e-skin has the self-healing ability after damage and remains excellent sensitivity to temperature and pressure after healing. A 5 × 5 device array was also fabricated, which can simultaneously image the pressure and temperature distribution.

Intestinal tract is an important organ for lowering serum uric acid in rats.

The kidney was recognized as a dominant organ for uric acid excretion. The main aim of the study demonstrated intestinal tract was an even more important organ for serum uric acid (SUA) lowering. Sprague-Dawley rats were treated normally or with antibiotics, uric acid, adenine, or inosine of the same molar dose orally or intraperitoneally for 5 days. Rat's intestinal tract was equally divided into 20 segments except the cecum. Uric acid in serum and intestinal segment juice was assayed. Total RNA in the initial intestinal tract and at the end ileum was extracted and sequenced. Protein expression of xanthine dehydrogenase (XDH) and urate oxidase (UOX) was tested by Western blot analysis. The effect of oral UOX in lowering SUA was investigated in model rats treated with adenine and an inhibitor of uric oxidase for 5 days. SUA in the normal rats was 20.93±6.98 µg/ml, and total uric acid in the intestinal juice was 308.27±16.37 µg, which is two times more than the total SUA. The uric acid was very low in stomach juice, and attained maximum in the juice of the first segment (duodenum) and then declined all the way till the intestinal end. The level of uric acid in the initial intestinal tissue was very high, where XDH and most of the proteins associated with bicarbonate secretion were up-regulated. In addition, SUA was decreased by oral UOX in model rats. The results suggested that intestinal juice was an important pool for uric acid, and intestinal tract was an important organ for SUA lowering. The uric acid distribution was associated with uric acid synthesis and secretion in the upper intestinal tract, and reclamation in the lower.

Excretory Function of Intestinal Tract Enhanced in Kidney Impaired Rats Caused by Adenine.

The main aim of the study was to prove the compensative effect of intestine for renal function. Rat kidney was impaired by intragastrically administrating adenine (400 mg per day for 5 days). Intestinal tract was harvested and equally divided into 20 segments except cecum. Kidneys were harvested and histologically examined with hematoxylin-eosin staining kits. Uric acid, urea (BUN), and creatinine in serum were determined with assay kits, and BUN and creatinine in every intestinal segment were also determined. The results showed that adenine was able to increase uric acid level in serum from 20.98 ± 6.98 µg/mL to 40.77 ± 7.52 µg/mL and cause renal function damage with BUN (from 3.87 ± 0.62 mM to 12.33 ± 3.27 mM) and creatinine (from 51.48 ± 6.98 µM to 118.25 ± 28.63 µM) increasing in serum and with abnormally micromorphological changes in kidney. The amount of BUN and creatinine distributed in intestinal tract was positively correlated with those in blood. In impaired renal function rats, the amount of BUN (from 4.26 ± 0.21 µMole to 10.72 ± 0.55 µMole) and creatinine (from 681.4 ± 23.3 nMole to 928.7 ± 21.3 nMole) distributed in intestinal tract significantly increased. All the results proved that intestinal tract had excretory function compensative for renal function.

The biological effects of individual-level PM(2.5) exposure on systemic immunity and inflammatory response in traffic policemen.

BACKGROUND: Ambient fine-particle particulate matter (PM2.5) exposure is associated with the decline in pulmonary function, prevalence of coronary heart disease and incidence of myocardial infarction. The study is to observe the effects of ambient PM2.5 on the cardiovascular system and to explore the potential inflammatory and immune mechanisms. METHODS: The subjects included 110 traffic policemen in Shanghai, China, who were aged 25-55 years. Two-times continuous 24 h individual-level PM2.5 measurements were performed in winter and summer, respectively. The inflammatory marker (high-sensitivity C-reactive protein, hs-CRP), immune parameters (IgA, IgG, IgM and IgE) and lymphocyte profiles (CD4 T cells, CD8 T cells, CD4/CD8 T cells) were measured in blood. The associations between individual-level PM2.5 and inflammatory marker and immune parameters were analysed by multiple linear regression. RESULTS: The average concentration of 24 h personal PM2.5 for participants was 116.98 µg/m(3) and 86.48 µg/m(3) in winter and summer, respectively. In the main analysis, PM2.5 exposure is associated with the increases in hs-CRP of 1.1%, IgG of 6.7%, IgM of 11.2% and IgE of 3.3% in participants, and decreases in IgA of 4.7% and CD8 of 0.7%, whereas we found no statistical association in CD4 T cells and CD4/CD8 T cells. In the adjusted model, the results showed that the increase of PM2.5 was associated with the changes of inflammatory markers and immune markers both in winter and summer. CONCLUSIONS: Traffic policeman have been a high-risk group suffering inflammatory response or immune injury because of the high exposure to PM2.5. These findings provided new insight into the mechanisms linking ambient PM2.5 and inflammatory and immune response.

[Effects of airborne fine particulate matter on human respiratory symptoms and pulmonary function].

OBJECTIVE: to explore effects of airborne fine particulate matter exposure on human respiratory symptoms and pulmonary function. METHODS: one hundred and seven field traffic policemen were recruited as airborne fine particulate matter high-exposure group and one hundred and one male residents as common exposure group. The individual sampler was used to measure fine particulate matter exposure levels of the two groups. To obtain personal information, especially respiratory symptoms such as cough, sputum, etc. a questionnaire survey was used. The pulmonary ventilation function was detected: forced expiratory vital capacity (FVC), the first 1 second forced expiratory volume (FEV1.0), FVC/FEV1.0% and peak flow values (PEF), and the difference of fine particulate matter exposure level and respiratory function of the two groups was compared. RESULTS: 24 h individual average fine particulate matter exposure concentration of traffic police and residents were respectively (115.4 ± 46.17) microg/m(3) and (74.94 ± 40.09) microg/m(3), the traffic police PM2.5 exposure levels were significantly higher than the residents. In the incidence of respiratory symptoms, compared with high-exposure group and common exposure group, coughing, expectoration, throat unwell, asthma, short of breath and nose discomfort, traffic police group was higher than residents group (P < 0.05). The abnormal rate of lung ventilation function indexes, such as FVC and FEV1.0 was 25.23% and 12.15% respectively in high-exposure group, 11.88% and 2.97% in common exposure group, there was no statistical difference between two groups. Besides, the abnormal rate of FVC and FEV1.0, showed rising trend in high-exposure group with seniority. CONCLUSION: long-term higher levels of airborne fine particulate matter exposure, may impact respiratory health and impair pulmonary function.

[Effects of airborne fine particulate matters on human immunological indicators].

OBJECTIVE: To explore effects of airborne fine particulate matters on human immunological indicators. METHODS: All subjects were measured the level of PM2. 5 individual exposure with personal sampling devices. Serum immunological indicators, such as WBC, NE, NE%, Ly, Ly%, CD4+, CD8+, CD4+ / CD8+, IgA, IgM, IgG and IgE were detected through enzyme-linked immunosorbent assay. Then, comparing the difference of PM2.5 exposure and immunological indicators between two groups. RESULTS: For the level of PM2.5 daily exposure, traffic policemen (115.4 +/- 46.2) microg/m3) was significantly higher than residents ((74.9 +/- 40.1) +/- g/ m(-3)). And there was also significant difference in some immunological indicators, such as Ly%, CD4+, CD8+, IgM, IgG, IgE, CC 16 and CRP, between two groups. CONCLUSION: Long-term high level of airborne fine particulate matters exposure may change some blood immunological indicators, affect the health of the immune system.