Conjugated Polymer-Based Nanocomposites for Pressure Sensors.

Flexible sensors are the essential foundations of pressure sensing, microcomputer sensing systems, and wearable devices. The flexible tactile sensor can sense stimuli by converting external forces into electrical signals. The electrical signals are transmitted to a computer processing system for analysis, realizing real-time health monitoring and human motion detection. According to the working mechanism, tactile sensors are mainly divided into four types-piezoresistive, capacitive, piezoelectric, and triboelectric tactile sensors. Conventional silicon-based tactile sensors are often inadequate for flexible electronics due to their limited mechanical flexibility. In comparison, polymeric nanocomposites are flexible and stretchable, which makes them excellent candidates for flexible and wearable tactile sensors. Among the promising polymers, conjugated polymers (CPs), due to their unique chemical structures and electronic properties that contribute to their high electrical and mechanical conductivity, show great potential for flexible sensors and wearable devices. In this paper, we first introduce the parameters of pressure sensors. Then, we describe the operating principles of resistive, capacitive, piezoelectric, and triboelectric sensors, and review the pressure sensors based on conjugated polymer nanocomposites that were reported in recent years. After that, we introduce the performance characteristics of flexible sensors, regarding their applications in healthcare, human motion monitoring, electronic skin, wearable devices, and artificial intelligence. In addition, we summarize and compare the performances of conjugated polymer nanocomposite-based pressure sensors that were reported in recent years. Finally, we summarize the challenges and future directions of conjugated polymer nanocomposite-based sensors.

Comparative Multi-Omics Analysis Reveals Lignin Accumulation Affects Peanut Pod Size.

Pod size is one of the important factors affecting peanut yield. However, the metabolites relating to pod size and their biosynthesis regulatory mechanisms are still unclear. In the present study, two peanut varieties (Tif and Lps) with contrasting pod sizes were used for a comparative metabolome and transcriptome analysis. Developing peanut pods were sampled at 10, 20 and 30 days after pegging (DAP). A total of 720 metabolites were detected, most of which were lipids (20.3%), followed by phenolic acids (17.8%). There were 43, 64 and 99 metabolites identified as differentially accumulated metabolites (DAMs) at 10, 20 and 30 DAP, respectively, and flavonoids were the major DAMs between Tif and Lps at all three growth stages. Multi-omics analysis revealed that DAMs and DEGs (differentially expressed genes) were significantly enriched in the phenylpropanoid biosynthesis (ko00940) pathway, the main pathway of lignin biosynthesis, in each comparison group. The comparisons of the metabolites in the phenylpropanoid biosynthesis pathway accumulating in Tif and Lps at different growth stages revealed that the accumulation of p-coumaryl alcohol (H-monolignol) in Tif was significantly greater than that in Lps at 30 DAP. The differential expression of gene-LOC112771695, which is highly correlated with p-coumaryl alcohol and involved in the biosynthesis of monolignols, between Tif and Lps might explain the differential accumulation of p-coumaryl alcohol. The content of H-lignin in genetically diverse peanut varieties demonstrated that H-lignin content affected peanut pod size. Our findings would provide insights into the metabolic factors influencing peanut pod size and guidance for the genetic improvement of the peanut.

Change of urinary fluoride and bone metabolism indicators in the endemic fluorosis areas of southern China after supplying low fluoride public water.

BACKGROUND: Few studies have evaluated health impacts, especially biomarker changes, following implementation of a new environmental policy. This study examined changes in water fluoride, urinary fluoride (UF), and bone metabolism indicators in children after supplying low fluoride public water in endemic fluorosis areas of Southern China. We also assessed the relationship between UF and serum osteocalcin (BGP), calcitonin (CT), alkaline phosphatase (ALP), and bone mineral density to identify the most sensitive bone metabolism indicators related to fluoride exposure. METHODS: Four fluorosis-endemic villages (intervention villages) in Guangdong, China were randomly selected to receive low-fluoride water. One non-endemic fluorosis village with similar socio-economic status, living conditions, and health care access, was selected as the control group. 120 children aged 6-12 years old were randomly chosen from local schools in each village for the study. Water and urinary fluoride content as well as serum BGP, CT, ALP and bone mineral density were measured by the standard methods and compared between the children residing in the intervention villages and the control village. Benchmark dose (BMD) and benchmark dose lower limit (BMDL) were calculated for each bone damage indicator. RESULTS: Our study found that after water source change, fluoride concentrations in drinking water in all intervention villages (A-D) were significantly reduced to 0.11 mg/l, similar to that in the control village (E). Except for Village A where water change has only been taken place for 6 years, urinary fluoride concentrations in children of the intervention villages were lower or comparable to those in the control village after 10 years of supplying new public water. The values of almost all bone indicators in children living in Villages B-D and ALP in Village A were either lower or similar to those in the control village after the intervention. CT and BGP are sensitive bone metabolism indicators related to UF. While assessing the temporal trend of different abnormal bone indicators after the intervention, bone mineral density showed the most stable and the lowest abnormal rates over time. CONCLUSIONS: Our results suggest that supplying low fluoride public water in Southern China is successful as measured by the reduction of fluoride in water and urine, and changes in various bone indicators to normal levels. A comparison of four bone indicators showed CT and BGP to be the most sensitive indicators.

[Bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach for osteoporotic vertebral compression fracture of lumbar].

OBJECTIVE: To evaluate the feasibility and short-term effectiveness of bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach for osteoporotic vertebral compression fracture (OVCF) of lumbar. METHODS: A retrospective analysis was made on the clinical data of 93 patients with OVCF of lumbar who met the selection criteria between January 2018 and June 2019. According to the different surgical methods, they were divided into group A (44 cases, treated with bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach) and group B [49 cases, treated with percutaneous kyphoplasty (PKP) via bilateral transpedicle approach]. There was no significant difference in gender, age, body mass index, T value of bone mineral density, injury cause, fractured level, time from injury to operation, comorbidities, and preoperative Cobb angle of injured vertebra, visual analogue scale (VAS) score, and Oswestry disability index (ODI) between the two groups ( P>0.05). The operation time, intraoperative fluoroscopy times, bone cement injection amount, and incidence of bone cement leakage were recorded and compared between the two groups; Cobb angle of the injured vertebrae, VAS score, and ODI were measured before operation, at 2 days and 1 year after operation. The contralateral distribution ratio of bone cement was calculated according to the anteroposterior X-ray film at 2 days after operation. RESULTS: The operation time and the intraoperative fluoroscopy times in group A were significantly less than those in group B ( P<0.05). There was no bone cement adverse reactions, cardiac and cerebrovascular adverse events, and no complications such as puncture needles erroneously inserted into the spinal canal and nerve injuries occurred in the two groups. Bone cement leakage occurred in 6 cases and 8 cases in groups A and B, respectively, all of which were asymptomatic paravertebral or intervertebral leakage, and no intraspinal leakage occurred; the bone cement injection amount and incidence of bone cement leakage between the two groups showed no significant differences ( P>0.05). The contralateral distribution ratio of bone cement in group A was significantly lower than that in group B ( t=2.685, P=0.009). Patients in both groups were followed up 12-20 months, with an average of 15.3 months. The Cobb angle of the injured vertebrae, VAS score, and ODI in the two groups were significantly improved at 2 days after operation, however, the Cobb angle of the injured vertebra at 1 year after operation was significantly lost when compared with the 2 days after operation, the VAS score and ODI at 1 year after operation were significantly further improved when compared with the 2 days after operation, the differences were all significant ( P<0.05). There was no significant difference in the Cobb angle of the injured vertebrae, VAS score, and ODI between the two groups at each time point after operation ( P>0.05). CONCLUSION: Bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach is comparable to bilateral PKP in short-term effectiveness with regard to fracture reduction, reduction maintenance, pain relief, and functional improvement. It has great advantages in reducing operation time and radiation exposure, although it is inferior in bone cement distribution.

Bioinspired, Self-Powered, and Highly Sensitive Electronic Skin for Sensing Static and Dynamic Pressures.

Flexible piezoresistive pressure sensors obtain global research interest owing to their potential applications in healthcare, human-robot interaction, and artificial nerves. However, an additional power supply is usually required to drive the sensors, which results in increased complexity of the pressure sensing system. Despite the great efforts in pursuing self-powered pressure sensors, most of the self-powered devices can merely detect the dynamic pressure and the reliable static pressure detection is still challenging. With the help of redox-induced electricity, a bioinspired graphite/polydimethylsiloxane piezoresistive composite film acting both as the cathode and pressure sensing layer, a neoteric electronic skin sensor is presented here to detect not only the dynamic forces but also the static forces without an external power supply. Additionally, the sensor exhibits a fascinating pressure sensitivity of ∼103 kPa-1 over a broad sensing range from 0.02 to 30 kPa. Benefiting from the advanced performance of the device, various potential applications including arterial pulse monitoring, human motion detecting, and Morse code generation are successfully demonstrated. This new strategy could pave a way for the development of next-generation self-powered wearable devices.

[Effects of soluble microbial product on the performance of submerged membrane bioreactor].

The behaviors of soluble microbial products (SMP) and SMP effects on an operational process of submerged membrane bioreactor (SMBR) were studied. Within 90 days performance period, total organic carbon (TOC), molecular weight distributions (MWDs), specific oxygen uptake rate (SOUR)were periodically monitored. The dead-end filtration tests were used to indicate the SMP effect on membrane fouling. Experiment results showed that the concentration of SMP in SMBR supernatant obviously accumulated. As the operation time was prolonged, the concentrations of SMP with MW > 10,000 remarkably increased in SMBR supernatant. Compared with the SMP of MW < 1,000, the SMP with MW > 10,000 obviously affected sludge activity and membrane fouling, but did not significantly influence the SMBR effluent.

[Effect of aeration intensity on the filterability of mixed liquor in membrane bioreactor].

The influence of aeration intensity on membrane fouling in membrane bioreactors (MBR) was to investigate. Two lab-scale MBR with aeration intensity of 500 and 100 L/h were operated for 60 days at a constant permeate flux. The dead-end filtration tests were conducted to confirm the mixed sludge filterability under each condition. The effect of aeration intensity on relative molecular mass distributions of SMP, the particle size distributions (PSD) of flocs and the quantity of extracellular polymeric substances (EPS) in MBRs were also tested. The results show that large aeration intensity has a negative influence on the filterability of mixed sludge in MBR. Further research finds that the large aeration intensity results in the increase of soluble microbial products (SMP) with a relative molecular mass (M(r)) > 10 000 in supernatant, which obviously affects the filtration of mixed sludge. It is also found that small particles in the range of 1-10 microm and the concentration of EPS in flocs remarkably increase under high aeration intensity of 500 L/h.

Effect of delayed pulsed-wave ultrasound on local pharmacokinetics and pharmacodynamics of vancomycin-loaded acrylic bone cement in vivo.

This study sought to investigate the effect of delayed pulsed-wave ultrasound with low frequency on drug release from and the antimicrobial efficacy of vancomycin-loaded acrylic bone cement in vivo and the possible mechanism of this effect. After the implantation of cement and the inoculation of Staphylococcus aureus into the bilateral hips of rabbits, ultrasound (average intensity, 300 mW/cm(2); frequency, 46.5 kHz; on/off ratio, 20 min/10 min) was applied to animals in the normal ultrasound group (UG(0-12)) from 0 through 12 h after surgery and to those in the delayed-ultrasound group (UG(12-24)) from 12 through 24 h after surgery. The control group (CG) was not exposed to ultrasound. Based on vancomycin concentrations in left hip cavities at projected time intervals, the amount of time during which the local drug concentration exceeded the MIC (T(>MIC)) in UG(12-24) was significantly prolonged compared with that in either CG or UG(0-12), and the ratios between the areas under the concentration-time curves over 24 h and the MIC for UG(0-12) and UG(12-24) were both increased compared with that for CG. The greatest reductions in bacterial densities in both right hip aspirates and right femoral tissues at 48 h were achieved with UG(12-24). Local hemorrhage in rabbits of UG(0-12) during the 12-h insonation was more severe than that in rabbits of UG(12-24). Of four variables, the T(>MIC) and the bioacoustic effect were both identified as parameters predictive of the enhancement of the antimicrobial efficacy of cement by ultrasound. Sustained concentrations above the MIC replaced early high maximum concentrations and long-term subtherapeutic release of the drug, provided that ultrasound was not applied until local hemorrhage was relieved. The enhancement of the antimicrobial efficacy of cement by ultrasound may be attributed to the prolonged T(>MIC) and the bioacoustic effect caused by ultrasound.