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A hepta-mode wideband microstrip antenna is proposed for use on the back cover of mobile terminals, targeting Wi-Fi 6/6E and ultrawideband (UWB) channels 5–11 MIMO applications. This multiple-input multiple-output (MIMO) ant- enna design comprises four elements arranged in a sequential rotation pattern, each featuring four small patches with two asymmetric notches. Through proper adjustment of patch and notch dimensions, seven modes are effectively excited by a rotated L-shaped feeding probe, thereby amplifying bandwidth of the proposed antenna. In addition, size miniaturization is achieved using a circle of blind vias. To validate the design strategy, a prototype of the MIMO antenna is constructed with dimensions measuring $60.6\times 60.6\times 2$ mm3. Meeting the requirements for mobile antenna specifications, the proposed MIMO antenna covers a wide range of frequencies, including Wi-Fi 6/6E and UWB channels 5–11, with a measured −6-dB impedance bandwidth of 5.14–9.05 GHz and an isolation of over 12 dB between each antenna element. Combining broad bandwidth, compact dimensions, and a low profile, this MIMO antenna demonstrates significant potential for supporting diverse wireless services on mobile terminals.

The branched fructooligosaccharides ABW90-1 and ABW50-1 from Achyranthes bidentatawith potent antiosteoporosis activities have been synthesized for the first time. The synthetic approach highlights the following features: (1) 6-O-picoloyl-directed β-d-fructofuranosylation via a hydrogen-bond-mediated aglycone delivery strategy for the highly stereoselective constructions of β-(2 → 6)-d-fructofuranosidic linkages and β-(2 → 1)-d-fructofuranosidic linkages in the internal positions under the reaction conditions (DBDMH, −20 °C, CH2Cl2) and (2) the reaction conditions (DBDMH, −78 °C to −35 °C, toluene) for highly stereoselective formations of β-(2 → 1)-d-fructofuranosidic linkages in the terminal positions.

In this article, we introduce a balanced broadband mu-near-zero (MNZ) loop antenna, which is designed for Wi-Fi 6/6E applications in full metal housing tablet computers. Different from the previous MNZ segmented loop antenna with the single $0^{\text {th}}$ mode, the higher order $1^{\text {st}}$ / $2^{\text {nd}}$ / $3^{\text {rd}}$ modes are also included for broadband purpose. By adjusting the effective permeability through the distributed capacitors in the proposed antenna, the electrical lengths of the $0^{\text {th}}$ / $1^{\text {st}}$ / $2^{\text {nd}}$ / $3^{\text {rd}}$ modes are reasonably stretched. This allows for multimode synergy in a single MNZ loop located in full metal housing computers. Therefore, the proposed MNZ loop antenna, with a planar structure of $6.8\times 45.4$ mm2, exhibits a broad bandwidth with $S_{11} \lt -6$ dB from 4.5 to 7.5 GHz, covering Wi-Fi 6/6E bands. As another merit for practical applications, this broadband MNZ loop antenna is also balanced with less current on the motherboard, performing excellent robustness against changes in tablet computer sizes or affecting by hands. The proposed MNZ loop antenna, with its multiple modes, offers valuable insights for the development of broadband and robust antennas in full metal housing devices.

In chemical and biological analysis, different substances have different requirements for RI detection. In this article, we propose and experimentally validate a molybdenum disulfide (MoS2)-modulated surface plasmon resonance (SPR) sensor. Due to the high effective refractive index (RI) of MoS2, the detection accuracy of the sensor after MoS2 modulation is good. The numerical simulation results verify that the MoS2 film has a good improvement effect on the performance of fiber sensing. The sensor is fabricated by coating a silver film and a MoS2 film on a photonic crystal fiber (PCF) using a magnetron sputtering method. First, the optimal sensing length and sputtering time of the silver film are determined experimentally, and the MoS2 film is coated on the optimal silver-based sensor. Experimental results show that the maximum sensitivity of the MoS2-modulated sensor in the detection range of RI from 1.415 to 1.420 is 16000 nm/RIU. The RI sensitivity of the MoS2-modulated sensor is increased by 167.35% compared with that of silver-based sensors, which means that the sensor is suitable for high-sensitivity detection applications of specific substances.

Fiber curvature sensors based on surface plasmon resonance (SPR) have lower curvature detection sensitivity compared to existing curvature sensors. However, they offer advantages that other sensors cannot match, including insensitivity to parameters such as temperature and axial strain. To improve the detection sensitivity of SPR curvature sensors, we propose a no-core fiber (NCF) curvature sensor that measures curvature based on the intensity modulation method. In this curvature sensor, NCF of ZnO/silver film sputtered by a magnetron sputtering method is used as the sensing probe, and multimode fibers (MMFs) are used as the input and output units for optical signals on both sides of the sensing probe. This curvature sensor does not need to cascade other devices to avoid the effect of cross-sensitivity, which meets the current trend of device miniaturization. Due to the excellent light-guiding ability of NCF, the resonance valley excited by the SPR effect is sensitive to small changes in curvature. The experimental results show that the maximum curvature sensitivity of the curvature sensor in the curvature detection range of 0–35 m−1 is 0.4424 dB/m−1 and its linearity can reach 0.95588. This curvature sensor has the advantages of miniaturization, insensitivity to temperature and axial strain, and high curvature sensitivity, providing a new method for fiber SPR curvature sensors.

Twist detection is of great significance in industrial production, aerospace, biomedicine, and other fields. Aiming at the problem of the low sensitivity of the twisted sensor, this article proposed and prepared a kind of fiber twist sensor with high sensitivity based on Sagnac interference. The sensitive area of the sensor is a helical elliptical-core polarization maintaining (HEPM) fiber, the optical fiber with an elliptical core has linear birefringence property, and when the fiber is rotated, it has circular birefringence property. The HEPM fiber is plugged into the light loop to form Sagnac interference. Since circular birefringence is proportional to the degree of fiber distortion, the interference spectral trough will respond to different angles of fiber torsion. In addition, the sensor can not only identify the twist direction but also maintain good stability in different twist directions. The experimental results show that the free spectral range (FSR) of the interference spectrum increases and the sensitivity of twist sensing increases as the length of the used HEPM fiber decreases. The maximum twist sensitivity that can be achieved is 8740.64 pm/(rad/m) when the length of HEPM fiber is 15 cm in the twist range of plus or negative 120°, which is higher than the sensitivity of existing studies. The proposed sensor can be used for high-sensitivity distortion sensing. The temperature stability of the sensor is studied experimentally, and a sensing matrix is established that can simultaneously measure the torsion and temperature to eliminate the error caused by temperature. In summary, the proposed sensor not only has high sensitivity but also has an excellent linear response and can identify the twist direction, which has great potential in practical distortion detection.

Sensitivity is an important index parameter for evaluating the performance of a sensor. To improve the sensitivity of the sensor, we propose and demonstrate a surface plasmon resonance (SPR) fiber sensor based on Ti3C2Tx-Mxene/silver film. A V-shaped photonic crystal fiber (V-PCF) is used as the sensing probe, and a silver film is deposited on its surface by magnetron sputtering to excite the SPR effect. Multimode fibers are used to transmit signals at both ends of the sensor probe. Simulation results show that light can be stably transmitted in the cladding of the V-PCF. Experimental results show that the refractive index (RI) measurement range of the sensor is between 1.333 and 1.420, and the maximum RI sensitivity is 20188 nm/RIU; In order to extend the detection function of the sensor, we coated PDMS film on the Ti3C2Tx-MXene/silver film. When the sensor is used to measure temperature, the maximum temperature sensitivity is 9.33 nm/°C in the range of 0 °C–100 °C. Therefore, the proposed composite film structure sensor in this paper has the advantages of ultra-high detection sensitivity and oxidation resistance, which can have a great competitive advantage in the sensing field.

In order to cope with the crosstalk between temperature and refractive index (RI) caused by high-temperature environments, this study proposes to modify the surface plasmon resonance (SPR) fiber optic sensors with molybdenum disulfide (MoS2). MoS2 efficiently modulates the resonance wavelength, enabling the sensor to operate in high-temperature environments. The effect of MoS2 film thickness on the resonance wavelength was investigated by depositing MoS2 film on the surface of no-core fiber (NCF) using the magnetron sputtering method. The analysis shows that MoS2 can induce a significant redshift of the resonance dip, and the degree of redshift is related to the film thickness. In addition, a dual-parameter SPR sensor capable of detecting RI at high temperatures was prepared in this work by selecting the optimal Ag film thickness and MoS2 film thickness. The sensor was obtained by cascading an Ag-based NCF with an Ag/MoS2-based NCF, which was simulated and tested experimentally. The results show that the maximum temperature sensitivity is 4.3 nm/°C over the 50 °C–90 °C temperature range. The maximum RI sensitivity is 5243.4 nm/RIU over the RI range of 1.333–1.395. The test results also show that the two channels of the sensor are independent of each other and have good stability. Therefore, Ag/MoS2-based SPR sensors have the advantages of adjustable bandwidth, dual-parameter independent detection, and high sensitivity. These are essential in the future fields of multiparameter sensing, compensated detection, and real-time biomonitoring.

Piezoelectric sensors are excellent damage detectors that can be applied to structural health monitoring (SHM). SHM for complex structures of aerospace vehicles working in harsh conditions is frequently required, posing challenging requirements for a sensor’s flexibility, radiation hardness, and high-temperature tolerance. Here, we fabricate a flexible and lightweight Pb(Zr0.53Ti0.47)O3piezoelectric film on flexible KMg3(AlSi3O10)F2substrate via van der Waals (vdW) heteroepitaxy, endowing it with robust ferroelectric and piezoelectric properties under low energy-high flux protons (LE-HFPs) radiation (1015p/cm2). More importantly, the Pb(Zr0.53Ti0.47)O3film sensor maintains highly stable damage monitoring sensitivity on an aluminum plate under harsh conditions of LE-HFPs radiation (1015p/cm2, flat structure), high temperature (175 °C, flat structure), and mechanical fatigue (bending 105cycles under a radius of 5 mm, curved structure). All these superior qualities are suggested to result from the outstanding film crystal quality due to vdW epitaxy. The flexible and lightweight Pb(Zr0.53Ti0.47)O3film sensor demonstrated in this work provides an ideal candidate for real-timeSHM of aerospace vehicles with flat and complex curve-like structures working in harsh aerospace environments.

Graphical Abstract: In the current work, different contents of Sr were added to the Al-6.5Si-20Cu-1.5Ni filler metal to improve the microstructure and brazing properties of filler metals which were used to braze 6063 aluminum alloy. When the addition of Sr was 0.08 wt.%, the brittle phases primary Si and Al-Si in the filler metal were refined completely and the shear strength of brazed joint achieved the greatest.

ABSTRACTTo investigate mechanism of pericytes in the early stage of subarachnoid haemorrhage (SAH) and its associated microvascular spasm and neurovascular injury, 100 healthy 8-week-old Sprague-Dawley male rats were taken as subjects and divided into four groups: group A (sham operation, control group), group B (SAH operation group), group C (SAH operation group treated with scutellarin), and group D (SAH operation group treated with L-nitro-arginine). 72 hours after the operation, the rats were conducted assessment of neurological impairment, observation of microangiography, detection of blood-brain barrier permeability, observation of skull base haemorrhage, identification of pericyte culture, and measurement of blood nitric oxide. The results showed that neurological impairment score, degree of micro-vasoconstriction, and BBB permeability of group C were significantly better than those of group B and D (P<0.05), there was no significant difference between group C and group A (P>0.05). There were significantly fewer blood clots in the brain of group C, and the order of expression levels of α-smooth muscle actin (α-SMA) in perioperative cells of the four groups from highest to lowest were D, B, C, and A. Nitric oxide concentration inhibited expression of α-SMA in pericytes after SAH at both protein and mRNA levels. The detection results of nitric oxide in the blood of four groups of rats confirmed that pericyte phenotype conversion and actin α-SMA expression could be prevented by upregulation of nitric oxide in serum, so as to relieve pathological symptoms after SAH operation.

ABSTRACTTo investigate the effect of miR-149-5p on sphingosine-1-phosphate receptor 2 (S1PR2) expression level and contents of matrix metalloproteinase (MMP-9) and superoxide dismutase (SOD) in the pericytes after acute cerebral ischemia reperfusion in rats, so as to clarify the neuroprotective molecular mechanism induced by miR-149-5p and provide references for the treatment of neurological diseases, 60 male SD rats aged 7–8 weeks were selected and divided randomly into test group (establishing middle cerebral artery occlusion (MCAO) model) and control group (no modeling). Rat pericytes and peripheral cerebral infarction tissues were collected 12 h, 1 d, 3 d, 5 d, and 7 d after MCAO modeling, respectively. The pericytes were identified by immunofluorescence assay (IFA) and transfected with miR-149-5p. Fluorescence quantitative PCR (FQPCR) and Western blot were adopted to detect S1PR2 expression level. The expression of S1PR2 in MCAO model rats was detected by IFA. Immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR) were used to detect the changes of MMP9 protein and mRNA levels of SOD1, SOD2, and SOD3 in brain tissue. The results showed that mRNA level and protein expression level of S1PR2 in the test group were higher than those in the control group three days after MCAO modeling (P< 0.05); the expression of S1PR2 increased 12 h after MCAO modeling and returned to the normal level on the 5th day, and the content of MMP9 protein in brain tissue of the test group was significantly lower than that of the control group (P< 0.05); the mRNA levels and SODs activity of SOD1, SOD2, and SOD3 in the test group were higher than those in the control group (P< 0.05). Therefore, miR-149-5p played a neuroprotective role by regulating S1PR2 to change the expression levels of SODS and MMP9.

Perovskite oxide SrSnO3has attracted considerable attentions recently due to its high carrier mobility and high transparency. Here, we experimentally and theoretically investigated the effects of La and Pb doping on the microstructure, band gaps, and electrical properties of SrSnO3epitaxial thin films. X-ray diffraction analysis showed that the in-plane lattice constants of Pb-doped SrSnO3(SrSn1–xPbxO3, x= 0–1, SSPO) films increased from 4.053 to 4.178 Å with the increase in Pb doping content. High-resolution transmission electron microscopy images revealed that SSPO films were coherently grown on LaAlO3(001) substrates. The optical band-gap values were considerably decreased gradually from 4.43 to 2.16 eV with Pb doping content while maintaining high optical transmittance in the visible wavelength range. Density functional theory calculations showed that the narrowing of band gap was attributed to a finite overlap between Pb 6s and Sn 5s orbitals around the bottom of the conduction band. As doping with 5% La in SSPO films, the electrical conductivity was improved greatly, and transport properties were investigated through temperature-dependent resistivity and Hall measurements. A lowest room-temperature resistivity of 0.5 mΩ cm and a maximum mobility of 39.9 cm2/Vs were observed in 5% La in the SSPO film at x= 1. Such wide-range tuning of the band gaps and excellent electrical properties of La- and Pb-doped SrSnO3epitaxial thin films may provide promising applications in optoelectronic devices.

Perovskite SrSnO3(SSO) thin films were epitaxially grown on LaAlO3(001) substrates by pulsed laser deposition at various oxygen pressures. X-ray diffraction was carried out to characterize the microstructure of the films, and the results showed that the unit-cell volume of the films increased gradually with lowering the growth oxygen pressures while remaining the perovskite structure. X-ray photoelectron spectroscopy results indicated that oxygen vacancies (OVs) existed in SSO thin films. Optical property measurements showed that all samples have a transmittance of more than 75% in the visible and near-infrared wavelength region. Furthermore, the band gaps of SSO films were found to increase from 4.56 to 5.21 eV with the decrease of deposition oxygen pressures calculated by linear fitting absorption edges of optical transmittance. In order to further ascertain the effect of OVs on band gaps of SSO films, the as-deposited 10 Pa film was annealed at 10–4Pa oxygen pressures and the band gap was found to increase by more than 1 eV. Density functional theory was used to explain the effects of OVs on band gaps and the ferromagnetism of SSO films, and the results suggested that an impurity energy level of OVs appeared near the Fermi level, causing the widening of the band gaps, which is consistent with our experimental results. Meanwhile, the room-temperature ferromagnetism was observed in the SSO films, and saturation magnetization increased gradually from 4.46 to 7.69 emu/cm3with decreasing the growth oxygen pressures.

Face masks are key personal protective equipment for reducing exposure to viruses and other environmental hazards such as air pollution. Integrating flexible and wearable sensors into face masks can provide valuable insights into personal and public health. The advantages that a breath-monitoring face mask requires, including multi-functional sensing ability and continuous, long-term dynamic breathing process monitoring, have been underdeveloped to date. Here, we design an effective human breath monitoring face mask based on a flexible La0.7Sr0.3MnO3(LSMO)/Mica respiration sensor. The sensor’s capabilities and systematic measurements are investigated under two application scenes, namely clinical monitoring mode and daily monitoring mode, to monitor, recognise, and analyse different human breath status, i.e., cough, normal breath, and deep breath. This sensing system exhibits super-stability and multi-modal capabilities in continuous and long-time monitoring of the human breath. We determine that during monitoring human breath, thermal diffusion in LSMO is responsible for the change of resistance in flexible LSMO/Mica sensor. Both simulated and experimental results demonstrate good discernibility of the flexible LSMO/Mica sensor operating at different breath status. Our work opens a route for the design of novel flexible and wearable electronic devices.

Objective:The aim of this study was to evaluate the feasibility and safety of multimodal therapy for patients with non-superacute vertebral basilar artery occlusion. Method:We performed a retrospective analysis of multimodal therapy for patients with vertebral basilar artery occlusion. All patients who were beyond the time window to receive intravenous thrombolysis and who had deterioration of symptoms after drug treatment received small-balloon dilatation of the occlusive artery to estimate vascular occlusion aetiology. Thrombectomy with a Solitaire AB system was applied to the thrombus, and angioplasty with intracranial stents was used to treat stenosis. During the 3-month follow-up, National Institute of Health Stroke Scale (NIHSS) and modified Rankin scale (mRS) scores were recorded regularly. Results:We included 12 patients with a mean age of 60.4 (SD: 12.9) years. The average score on the NIHSS was 16.6 (SD: 11.6), and the average time from onset to admission was 95 h (SD: 121). The arteries were recanalized for all patients, but the degree of residual stenosis in the parent artery was 17.5% (SD: 20.1). During the follow-up period, one patient died of pulmonary haemorrhage and infection, and another patient died from haemorrhage related to high perfusion. After 3 months of follow-up, the 10 surviving patients showed an average NIHSS score of 7.9 (SD: 8.7) and an average mRS score below 2 (1.3 ± 1.4). Conclusion:For patients with posterior circulation stroke due to basilar artery or vertebral artery occlusion who present to the hospital 6 h after symptom onset and who exhibit deterioration of symptoms after drug treatment, multimodal recanalization of the occluded artery may be a feasible and safe therapy.

•1. Changes in human settlement distribution during the Shang and Western Zhou dynasties were analyzed.•2. Extreme flooding and associated hydrological changes during the late Shang dynasty likely influenced settlement distribution patterns.•3. Ancient inhabitants probably responded to flooding by raising their dwellings.

The temporal-spatial distribution features of prehistoric cultures since the Holocene in Zhejiang region were comparatively analyzed based on GIS spatial analysis. Results show that the prehistoric cultures expanded gradually in this region before 4000 cal. a BP. The notable expansions occurred twice, one in the Majiabang-Hemudu cultural period, the other in the Liangzhu cultural period. Meanwhile, the prehistoric cultures were disseminated from west to east coast along river valleys. After 4000 cal. a BP, as represented by the Maqiao Culture, the distributed area of each prehistoric culture contracted. This is obviously due to the termination of spreading trends to east coast, which was simultaneously accompanied by two different modes of production and economic transitions in the north and south Zhejiang region respectively. The distribution of prehistoric cultures was closely related with Holocene sea-level fluctuations, especially on the banks of Hangzhou Bay, where the distribution changes of prehistoric cultural sites were greatly affected by sea-level changes, with the closest relationships between them. After 7000 cal. a BP, the process of lowered sea-level and regression-epeirogenesis provided wider terrestrial living spaces for prehistoric inhabitants. Based on the comparative analyses of the changes of prehistoric cultures and the environmental evolution information recorded in the Qianmutian subalpine peat of Mt. Tianmu and muddy area on the inner shelf of the East China Sea, it is indicated that the changes of prehistoric cultures were synchronized with environmental changes in Zhejiang region. Before 4000 cal. a BP, the eastward expansion of prehistoric cultures in Zhejiang occurred under the background of the Holocene Optimum, and was the expansion and extension under the joint influences of agricultural civilization and maritime civilization. However, after 4000 cal. a BP, the geographical contraction of prehistoric cultures in Zhejiang occurred under the back ground of dry-cold climate trend and deterioration of coastal marine environment. It is evidenced from the above fact that the development, expansion and contraction of prehistoric cultures are positively correlated to environmental change. The change of the climatic environment is just the underlying reason for these changes and transitions of production modes and economic forms. Therefore, the climatic environment is the dominant factor of prehistoric culture vicissitudes in Zhejiang region, which has exerted great influence on distribution, dissemination, expansion and transmutation of the culture.

This study presents an analysis of the spatial-temporal distribution of 230 archaeological sites in Guizhou Province, Southwest China for three selected time periods from the Paleolithic Age to the Shang-Zhou Dynasties. The relationship between archaeological sites distribution and environmental changes is also discussed based on paleo-environmental proxies of δ18O and δ13C recorded in stalagmites from Southwest China. The results show that: in the Paleolithic Age (260−10 ka BP), archaeological sites were concentrated in the central, northwestern and southwestern parts of Guizhou, where the high-altitudinal karst landforms with many natural caves suitable for human habitation are developed. In the Neolithic Age (10−3.6 ka BP), most of human settlements were concentrated in the central, northwestern and southwestern parts, while, a fewer sites were found on river terraces in the southern and eastern parts, and the intermontane basins in the central and western Guizhou. During the Shang-Zhou Dynasties (3.6−2.2 ka BP), the sites were mainly distributed in the intermontane basins and on river terraces, which were suitable for primitive aerial farming. The analysis of paleo-environmental proxies of δ18O and δ13C since 260 ka BP suggested that climate fluctuations had little impact on human settlements in this study area. The distinct physical environment, especially the spatial patterns of karst landforms and arable land played an important role in the archaeological sites distribution of Guizhou.

The formation of eight biogenic amines (BAs), total volatile base nitrogen (TVB-N), aerobic plate counts (APC), and sensory evaluation in crucian carp (Carassius auratus) during storage in ice and at 4°C were investigated. The sum of contents of all eight biogenic amines (SBA) in crucian carp increased from 49.82 to 197.09 mg/kg on day 36 when stored in ice and from 49.82 to 219.35 mg/kg on day 24 when stored at 4°C. TVB-N content increased with storage time; good relationships between TVB-N content and SBA were observed during storage in ice and at 4°C (R2= 0.95 and 0.93, respectively). APC of all samples significantly (P< 0.05) increased with storage time in the first 12 days and toward the end of the storage period, there were only minor changes; good relationships between APC and SBA were observed during storage in ice and at 4°C (R2= 0.96 and 0.58, respectively). According to sensory evaluation results, the crucian carp became unacceptable on days 24 and 16 during storage in ice and at 4°C, respectively. Putrescine and tyramine contents could be good quality evaluation indices for crucian carp during storage.