Terahertz liquid crystal programmable metasurface based on resonance switching.

A programmable metasurface based on liquid crystal is of great significance to versatile dynamic wave manipulation such as beamforming and beam steering. One of the biggest obstacles currently is the lack of a simple way to multi-bit programming scheme for massive electrically addressable arrays, which limits its application and magnifies drawbacks like unavoidable symmetrical beam diffraction. Here, we put forward the concept of a liquid crystal metasurface based on a resonance switching mechanism for quasi-2-bit coding control, which is established upon interdigital structure electrodes. This enables a more elaborate control of meta-unit and a quasi-2-bit modulation based on a universal binary coding system to be realized. Our design could suppress unwanted -1 diffraction order with a maximum single-beam scanning angle of ± 21° under active beam manipulation. This concept paves the way for a feasible and robust multi-bit coding scheme of a liquid crystal metasurface, which is promising for THz applications such as spatial light modulators and wireless communication.

Association of dialysate calcium concentration with fetuin A level and carotid intima-media thickness in peritoneal dialysis patients.

Serum fetuin A has been shown to be associated with the risk of vascular calcification and atherosclerosis, and it can predict the onset of cardiovascular mortality in dialysis patients. The carotid intima-media thickness (cIMT) is an accessible and reliable method to identify the subclinical atherosclerosis. The aim of this study was to investigate the relationships between dialysate calcium concentrations and fetuin A or cIMT in patients undergoing peritoneal dialysis (PD). Forty patients, newly diagnosed end-stage renal disease (ESRD) and undergoing peritoneal dialysis, were enrolled in the study, with a calcium content of the peritoneal dialysis (PD) solution of 1.25 mmol/L in 20 patients (low-Ca group) and 1.75 mmol/L in 20 patients (standard-Ca group). The patients were followed up for 12 months after the PD conducted. Serum fetuin A was determined using a human fetuin A enzyme-linked immunosorbent assay kit and cIMT was detected using ultrasonic wave. We observed no difference between two groups with regard to the baseline data of fetuin A, cIMT, calcium, phosphorus, calcium-phosphorus product, high sensitivity CRP (hsCRP), parathyroid hormone (PTH), or lipid parameters. After 12 months follow-up, fetuin A (263.92 ± 16.1 vs. 282.76 ± 21.0, p = 0.017) and calcium-phosphorus product (39.85 ± 7.76 vs. 47.50 ± 6.65, p = 0.009) were obviously lower in the low-Ca group than standard-Ca group, the other serum parameters were not different between these two groups. Compared with baseline data, serum fetuin A concentration significantly reduced in low-Ca group ( p < 0.05). The number of patients with increased cIMT and newly occurring cardiovascular events in the low-Ca group were significantly reduced than standard-Ca group ( p < 0.05). In conclusion, our data suggest that low calcium dialysate treatment is associated with the decreased serum fetuin A concentration and serum calcium-phosphorus product, and it is associated with the reduced number of PD patients with increased cIMT or with newly occurring cardiovascular events. However, more studies with lager sample size should be performed in the future.

Multilevel Printed Wearable Radio-Frequency Intelligent Identification Platform for Object Recognition.

As a noncontact target recognition technique, radio-frequency identification (RFID) technology demonstrates attractive potential in constructing human-machine interaction (HMI) systems. However, the current development of RFID technologies in HMI systems is hampered by critical challenges in manufacturing high-performance RFID readers with superior flexibility and wearing comfort. Hence, we propose a multilevel printing strategy to overcome the difficulties in manufacturing high-performance large-scale microwave systems. Compared to traditional processes, the RFID system fabricated by the hybrid additive manufacturing technique exhibits equivalent electromagnetic performance and has obvious advantages in terms of manufacturing cost and environmental friendliness. A printed reconfigurable antenna with intelligent radiation mode is seamlessly integrated with the reader circuit via a "one-step" printing technology. Additionally, through chemical doping and artificial intelligence (AI) prediction, we have developed a modified polydimethylsiloxane (PDMS) encapsulation to miniaturize the system volume and enhance reliability. Electromagnetic and mechanical measurements demonstrated that our flexible RFID platform offers superior reliability and stability during long-term daily use. The RFID platform possesses exceptional capabilities in target positioning and accurate identification, demonstrating unique potential in noncontact sensing and recognition, which are highly demanded by flexible and wearable HMI systems.

[Relations of fetuin-A with estimated glomerular filtration rate and carotid artery calcification in patients with chronic kidney disease].

OBJECTIVE: To investigate the association of fetuin-A with residual renal function and carotid artery calcification in patients with chronic kidney disease (CKD). METHODS: Blood examples were collected form 60 CKD patients in stages CKD3 to CKD5 (20 patients per stage) for measurement of serum fetuin-A, albumin, calcium, phosphorus and parathyroid hormone, cholesterol, triglycercide, low-density lipoprotein, and high-density lipoprotein. MDRD equation was used to calculate the estimated glomerular filtration rate (eGFR), and ELISA was used to detect serum fetuin-A. Color Doppler ultrasound was performed to measure carotid intima-media thickness (CIMT). RESULTS: As the eGFR decreased, serum fetuin-A significantly decreased in CKD5 stage compared with that in CKD4 stage (P<0.05); compared with that in CKD3 stage, serum fetuin-A level was significantly lowered in CKD4 stage (P<0.05). Linear regression analysis suggested a significant positive correlation between fetuin-A and eGFR. The rate of carotid artery calcification was the highest in CKD5 stage. Rank correlation analysis showed a negative correlation between fetuin-A and cIMT, and logistic regression analysis identified decreased serum Fetuin-A as a risk factor of carotid artery calcification. CONCLUSION: Serum fetuin-A decreases following the decrease in eGFR, and decreased serum Fetuin-A level is a risk factor of carotid artery calcification in CKD patients.