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1.
Nat Commun ; 15(1): 3838, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714685

RESUMO

The powerful capability of reconfigurable intelligent surfaces (RISs) in tailoring electromagnetic waves and fields has put them under the spotlight in wireless communications. However, the current designs are criticized due to their poor frequency selectivity, which hinders their applications in real-world scenarios where the spectrum is becoming increasingly congested. Here we propose a filtering RIS to feature sharp frequency-selecting and 2-bit phase-shifting properties. It permits the signals in a narrow bandwidth to transmit but rejects the out-of-band ones; meanwhile, the phase of the transmitted signals can be digitally controlled, enabling flexible manipulations of signal propagations. A prototype is designed, fabricated, and measured, and its high quality factor and phase-shifting characteristics are validated by scattering parameters and beam-steering phenomena. Further, we conduct a wireless communication experiment to illustrate the intriguing functions of the RIS. The filtering behavior enables the RIS to perform wireless signal manipulations with anti-interference ability, thus showing big potential to advance the development of next-generation wireless communications.

2.
Acta Biomater ; 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38761961

RESUMO

The regenerative microenvironment after peripheral nerve injury is imbalanced and difficult to rebalance, which is mainly affected by inflammation, oxidative stress, and inadequate blood supply. The difficulty in remodeling the nerve regeneration microenvironment is the main reason for slow nerve regeneration. Traditional drug treatments have certain limitations, such as difficulty in penetrating the blood-nerve barrier and lack of pleiotropic effects. Therefore, there is an urgent need to build multifunctional nerve grafts that can effectively regulate the regenerative microenvironment and promote nerve regeneration. Nitric oxide (NO), a highly effective gas transmitter with diatomic radicals, is an important regulator of axonal growth and migration, synaptic plasticity, proliferation of neural precursor cells, and neuronal survival. Moreover, NO provides potential anti-inflammation, anti-oxidation, and blood vessel promotion applications. However, excess NO may cause cell death and neuroinflammatory cell damage. The prerequisite for NO treatment of peripheral nerve injury is that it is gradually released over time. In this study, we constructed an injectable NO slow-release system with two main components, including macromolecular NO donor nanoparticles (mPEG-P(MSNO-EG) nanoparticles, NO-NPs) and a carrier for the nanoparticles, mPEG-PA-PP injectable temperature-sensitive hydrogel. Due to the multiple physiological regulation of NO and better physiological barrier penetration, the conduit effectively regulates the inflammatory response and oxidative stress of damaged peripheral nerves, promotes nerve vascularization, and nerve regeneration and docking, accelerating the nerve regeneration process. STATEMENT OF SIGNIFICANCE: The slow regeneration speed of peripheral nerves is mainly due to the destruction of the regeneration microenvironment. Neural conduits with drug delivery capabilities have the potential to improve the microenvironment of nerve regeneration. However, traditional drugs are hindered by the blood nerve barrier and cannot effectively target the injured area. NO, an endogenous gas signaling molecule, can freely cross the blood nerve barrier and act on target cells. However, excessive NO can lead to cell apoptosis. In this study, a NO sustained-release system was constructed to regulate the microenvironment of nerve regeneration through various pathways and promote nerve regeneration.

3.
Sci Bull (Beijing) ; 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38594099

RESUMO

Magnetic impurities in superconductors are of increasing interest due to emergent Yu-Shiba-Rusinov (YSR) states and Majorana zero modes for fault-tolerant quantum computation. However, a direct relationship between the YSR multiple states and magnetic anisotropy splitting of quantum impurity spins remains poorly characterized. By using scanning tunneling microscopy, we systematically resolve individual transition-metal (Fe, Cr, and Ni) impurities induced YSR multiplets as well as their Zeeman effects in the K3C60 superconductor. The YSR multiplets show identical d orbital-like wave functions that are symmetry-mismatched to the threefold K3C60(1 1 1) host surface, breaking point-group symmetries of the spatial distribution of YSR bound states in real space. Remarkably, we identify an unprecedented fermion-parity-preserving quantum phase transition between ground states with opposite signs of the uniaxial magnetic anisotropy that can be manipulated by an external magnetic field. These findings can be readily understood in terms of anisotropy splitting of quantum impurity spins, and thus elucidate the intricate interplay between the magnetic anisotropy and YSR multiplets.

4.
Pediatr Res ; 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38600299

RESUMO

BACKGROUND: Intermittent hypoxemia (IH) may influence retinopathy of prematurity (ROP) development in preterm infants, however, previous studies had mixed results. This study tests the hypothesis that increased IH is associated with Type 1 ROP; a stage beyond which treatment is indicated. METHODS: IH was quantified by continuously monitoring oxygen saturation (SpO2) using high-resolution pulse oximeters during the first 10 weeks of life. Statistical analyses assessed the relationship and predictive ability of weekly and cumulative IH for Type 1 ROP development. RESULTS: Most analyses showed no association between IH and Type 1 ROP adjusting for gestational age (GA) and birth weight (BW). However, cumulative IH of longer duration during weeks 5-10, 6-10, and 7-10 were significantly associated with Type 1 ROP adjusting for GA and BW, e.g., the adjusted odds ratio of Type 1 ROP was 2.01 (p = 0.03) for every 3.8 seconds increase in IH duration from week 6-10. IH did not provide statistically significant added predictive ability above GA and BW. CONCLUSIONS: For most analyses there was no significant association between IH and Type 1 ROP adjusting for GA and BW. However, infants with longer IH duration during the second month of life had higher risk for Type 1 ROP. IMPACT: The relationship and predictive ability of intermittent hypoxemia (IH) on retinopathy of prematurity (ROP) is controversial. This study shows no significant association between IH events and Type 1 ROP after adjusting for gestational age (GA) and birth weight (BW), except for cumulative IH of longer duration in the second month of life. In this cohort, IH does not provide a statistically significant improvement in ROP prediction over GA and BW. This study is the first to assess the cumulative impact of IH measures on Type 1 ROP. Interventions for reducing IH duration during critical postnatal periods may improve ROP outcomes.

5.
Nat Commun ; 15(1): 3157, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605044

RESUMO

Large-scale stretchable strain sensor arrays capable of mapping two-dimensional strain distributions have gained interest for applications as wearable devices and relating to the Internet of Things. However, existing strain sensor arrays are usually unable to achieve accurate directional recognition and experience a trade-off between high sensing resolution and large area detection. Here, based on classical Mie resonance, we report a flexible meta-sensor array that can detect the in-plane direction and magnitude of preloaded strains by referencing a dynamically transmitted terahertz (THz) signal. By building a one-to-one correspondence between the intrinsic electrical/magnetic dipole resonance frequency and the horizontal/perpendicular tension level, arbitrary strain information across the meta-sensor array is accurately detected and quantified using a THz scanning setup. Particularly, with a simple preparation process of micro template-assisted assembly, this meta-sensor array offers ultrahigh sensor density (~11.1 cm-2) and has been seamlessly extended to a record-breaking size (110 × 130 mm2), demonstrating its promise in real-life applications.

6.
Materials (Basel) ; 17(8)2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38673122

RESUMO

Understanding the mechanical properties of coal is crucial for efficient mining and disaster prevention in coal mines. Coal contains numerous cracks and fissures, resulting in low strength and challenges in preparing standard samples for testing coal fracture toughness. In engineering, indicators such as the hardness coefficient (f value) and Hardgrove grindability index (HGI) are straightforward to measure. Various experiments, including drop weight, grinding, uniaxial compressive strength and three-point bending experiments, were conducted using notched semi-circular bend (NSCB) specimens and particle sizes of 1-2 mm/0.425-1 mm. Theoretical and experimental results indicate that the hardness coefficient of coal and rock is proportional to the crushing work ratio and inversely proportional to the mean equivalent diameter. Moreover, the square of the fracture toughness of coal and rock is directly proportional to the crushing work ratio, inversely proportional to the newly added area, directly proportional to the mean equivalent diameter and directly proportional to the hardness coefficient. The Mode-I fracture toughness of coal and rock can be rapidly determined through the density, the equivalent diameter after crushing and the elastic modulus, with experimental verification of its accuracy. Considering that smaller particle sizes exhibit greater resistance to breakage, the distribution mode of new surface areas after particle breakage was established, influenced by the initial particle size and the energy of a single broken particle. This study can assist in quickly and accurately determining the fracture toughness of coal.

7.
IEEE Trans Image Process ; 33: 3145-3160, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38656843

RESUMO

Multi-view subspace clustering (MVSC) has drawn significant attention in recent study. In this paper, we propose a novel approach to MVSC. First, the new method is capable of preserving high-order neighbor information of the data, which provides essential and complicated underlying relationships of the data that is not straightforwardly preserved by the first-order neighbors. Second, we design log-based nonconvex approximations to both tensor rank and tensor sparsity, which are effective and more accurate than the convex approximations. For the associated shrinkage problems, we provide elegant theoretical results for the closed-form solutions, for which the convergence is guaranteed by theoretical analysis. Moreover, the new approximations have some interesting properties of shrinkage effects, which are guaranteed by elegant theoretical results. Extensive experimental results confirm the effectiveness of the proposed method.

8.
BMC Genomics ; 25(1): 426, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38684965

RESUMO

BACKGROUND: In the beef industry, bull calves are usually castrated to improve flavor and meat quality; however, this can reduce their growth and slaughter performance. The gut microbiota is known to exert a significant influence on growth and slaughter performance. However, there is a paucity of research investigating the impact of castration on gut microbiota composition and its subsequent effects on slaughter performance and meat flavor. RESULT: The objective of this study was to examine the processes via which castration hinders slaughter productivity and enhances meat quality. Bull and castrated calves were maintained under the same management conditions, and at slaughter, meat quality was assessed, and ileum and epithelial tissue samples were obtained. The research employed metagenomic sequencing and non-targeted metabolomics techniques to investigate the makeup of the microbiota and identify differential metabolites. The findings of this study revealed the Carcass weight and eye muscle area /carcass weight in the bull group were significantly higher than those in the steer group. There were no significant differences in the length, width, and crypt depth of the ileum villi between the two groups. A total of 53 flavor compounds were identified in the two groups of beef, of which 16 were significantly higher in the steer group than in the bull group, and 5 were significantly higher in the bull group than in the steer group. In addition, bacteria, Eukaryota, and virus species were significantly separated between the two groups. The lipid metabolism pathways of α-linolenic acid, linoleic acid, and unsaturated fatty acids were significantly enriched in the Steers group. Compared with the steer group, the organic system pathway is significantly enriched in the bull group. The study also found that five metabolites (LPC (0:0/20:3), LPC (20:3/0:0), LPE (0:0/22:5), LPE (22:5/0:0), D-Mannosamine), and three species (s_Cloning_vector_Hsp70_LexA-HP1, s_Bacteroides_Coprophilus_CAG: 333, and s_Clostridium_nexile-CAG: 348) interfere with each other and collectively have a positive impact on the flavor compounds of beef. CONCLUSIONS: These findings provide a basic understanding that under the same management conditions, castration does indeed reduce the slaughter performance of bulls and improve the flavor of beef. Microorganisms and metabolites contribute to these changes through interactions.


Assuntos
Microbioma Gastrointestinal , Íleo , Carne Vermelha , Animais , Bovinos , Masculino , Carne Vermelha/microbiologia , Íleo/microbiologia , Íleo/metabolismo , Metabolômica
9.
Chem Sci ; 15(10): 3524-3529, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38454999

RESUMO

An unprecedented fluoroarylation of 1,1-difluoroallenes with a cost-effective nucleophilic fluoride reagent and aryldiazonium salts is reported. This visible light promoted gold-catalyzed reaction allows a stereo- and regioselective incorporation of both the fluorine atom and aryl group, enabling a straightforward construction of multi-substituted trifluoromethyl alkenes. Under the mild reaction conditions, a nice tolerance of diverse functional groups is achieved. The high regioselectivity for fluorine-incorporation is rationalized by considering the thermodynamic driving force of trifluoromethyl group formation, whereas the counterintuitive stereoselectivity that aryl is installed on the side of the bulkier γ-substituent is interpreted by alleviating the increasing 1,3-allylic interaction in the gold-coordinated allene intermediate en route to the product.

10.
Eur J Pharmacol ; 970: 176491, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38503399

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disease with the hallmark of aggregation of beta-amyloid (Aß) into extracellular fibrillar deposition. Accumulating evidence suggests that soluble toxic Aß oligomers exert diverse roles in neuronal cell death, oxidative stress, neuroinflammation, and the eventual pathogenesis of AD. Aß is derived from the sequential cleavage of amyloid-ß precursor protein (APP) by ß-secretase (BACE1) and γ-secretase. The current effect of single targeting is not ideal for the treatment of AD. Therefore, developing multipotent agents with multiple properties, including anti-Aß generation and anti-Aß aggregation, is attracting more attention for AD treatment. Previous studies indicated that Quercetin was able to attenuate the effects of several pathogenetic factors in AD. Here, we showed that naturally synthesized Quercetin-3-O-glc-1-3-rham-1-6-glucoside (YCC31) could inhibit Aß production by reducing ß-secretase activity. Further investigations indicated that YCC31 could suppress toxic Aß oligomer formation by directly binding to Aß. Moreover, YCC31 could attenuate Aß-mediated neuronal death, ROS and NO production, and pro-inflammatory cytokines release. Taken together, YCC31 targeting multiple pathogenetic factors deserves further investigation for drug development of AD.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Humanos , Secretases da Proteína Precursora do Amiloide/metabolismo , Quercetina/farmacologia , Quercetina/uso terapêutico , Citocinas , Ácido Aspártico Endopeptidases/metabolismo , Ácido Aspártico Endopeptidases/uso terapêutico , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Glucosídeos/uso terapêutico
11.
Adv Sci (Weinh) ; 11(19): e2306850, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38477543

RESUMO

Micro-Doppler effect is a vital feature of a target that reflects its oscillatory motions apart from bulk motion and provides an important evidence for target recognition with radars. However, establishing the micro-Doppler database poses a great challenge, since plenty of experiments are required to get the micro-Doppler signatures of different targets for the purpose of analyses and interpretations with radars, which are dramatically limited by high cost and time-consuming. Aiming to overcome these limits, a low-cost and powerful simulation platform of the micro-Doppler effects is proposed based on time-domain digital coding metasurface (TDCM). Owing to the outstanding capabilities of TDCM in generating and manipulating nonlinear harmonics during wave-matter interactions, it enables to supply rich and high-precision electromagnetic signals with multiple micro-Doppler frequencies to describe the micro-motions of different objects, which are especially favored for the training of artificial intelligence algorithms in automatic target recognition and benefit a host of applications like imaging and biosensing.

12.
Angew Chem Int Ed Engl ; 63(21): e202400769, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38544401

RESUMO

Generating circularly polarized luminescence (CPL) with simultaneous high photoluminescence quantum yield (PLQY) and dissymmetry factor (glum) is difficult due to usually unmatched electric transition dipole moment (µ) and magnetic transition dipole moment (m) of materials. Herein we tackle this issue by playing a "cascade cationic insertion" trick to achieve strong CPL (with PLQY of ~100 %) in lead-free metal halides with high glum values reaching -2.3×10-2 without using any chiral inducers. Achiral solvents of hydrochloric acid (HCl) and N, N-dimethylformamide (DMF) infiltrate the crystal lattice via asymmetric hydrogen bonding, distorting the perovskite structure to induce the "intrinsic" chirality. Surprisingly, additional insertion of Cs+ cation to substitute partial (CH3)2NH2 + transforms the chiral space group to achiral but the crystal maintains chiroptical activity. Further doping of Sb3+ stimulates strong photoluminescence as a result of self-trapped excitons (STEs) formation without disturbing the crystal framework. The chiral perovskites of indium-antimony chlorides embedded on LEDs chips demonstrate promising potential as CPL emitters. Our work presents rare cases of chiroptical activity of highly luminescent perovskites from only achiral building blocks via spontaneous resolution as a result of symmetry breaking.

13.
Huan Jing Ke Xue ; 45(2): 678-688, 2024 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-38471908

RESUMO

Based on the one-year observational data of volatile organic compounds (VOCs) in an urban area of Yuncheng in 2021, the concentration, composition, sources, and ozone-sensitive species of VOCs in four seasons were analyzed. The results showed that the average annual concentration of VOCs was (32.1 ±24.2)×10-9, i.e., at the national middle level. The seasonal concentrations of VOCs were in the order of: winter (46.3×10-9)> autumn (35.5×10-9)> spring (25.6×10-9)> summer (21.2×10-9). Alkanes and OVOCs were the most dominant VOCs compounds, accounting for 69.0%-80.4% of TVOCs in Yuncheng. Affected by changes in source emissions, the proportion of OVOCs was higher in spring and summer (41%-43%), whereas the proportion of alkanes was higher in autumn and winter (42%-43%). Vehicle exhaust, LPG/NG, industrial production, and combustion sources were identified as the main sources of VOCs in Yuncheng. The largest contributors in the four seasons were vehicle exhaust (28.5% in spring), secondary + combustion sources (29.0% in summer), LPG/NG sources (30.4% in autumn), and coal combustion (27.3% in winter). The ozone formation was located in the transitional regime in summer and in the VOC-limited regime in other seasons. Ozone production was more sensitive to alkenes (isoprene, ethylene, and propene), OVOCs (acetaldehyde and propanal), and aromatics (xylene, toluene, and benzene). Winter was more sensitive to ethylene, and the other seasons were more sensitive to isoprene. The primary emission sources related to these sensitive species should be reduced to achieve the goal of air quality improvement.

14.
Natl Sci Rev ; 11(3): nwad299, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38312383

RESUMO

A digital coding metasurface is a platform connecting the digital space and electromagnetic wave space, and has therefore gained much attention due to its intriguing value in reshaping wireless channels and realizing new communication architectures. Correspondingly, there is an urgent need for electromagnetic information theory that reveals the upper limit of communication capacity and supports the accurate design of metasurface-based communication systems. To this end, we propose a macroscopic model and a statistical model of the digital coding metasurface. The macroscopic model uniformly accommodates both digital and electromagnetic aspects of the meta-atoms and predicts all possible scattered fields of the digital coding metasurface based on a small number of simulations or measurements. Full-wave simulations and experimental results show that the macroscopic model is feasible and accurate. A statistical model is further proposed to correlate the mutual coupling between meta-atoms with covariance and to calculate the entropy of the equivalent currents of digital coding metasurface. These two models can help reconfigurable intelligent surfaces achieve more accurate beamforming and channel estimation, and thus improve signal power and coverage. Moreover, the models will encourage the creation of a precoding codebook in metasurface-based direct digital modulation systems, with the aim of approaching the upper limit of channel capacity. With these two models, the concepts of current space and current entropy, as well as the analysis of information loss from the coding space to wave space, is established for the first time, helping to bridge the gap between the digital world and the physical world, and advancing developments of electromagnetic information theory and new-architecture wireless systems.

15.
Biomacromolecules ; 25(3): 1509-1526, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38376392

RESUMO

The multifaceted process of nerve regeneration following damage remains a significant clinical issue, due to the lack of a favorable regenerative microenvironment and insufficient endogenous biochemical signaling. However, the current nerve grafts have limitations in functionality, as they require a greater capacity to effectively regulate the intricate microenvironment associated with nerve regeneration. In this regard, we proposed the construction of a functional artificial scaffold based on a "two-pronged" approach. The whole system was developed by encapsulating Tazarotene within nanomicelles formed through self-assembly of reactive oxygen species (ROS)-responsive amphiphilic triblock copolymer, all of which were further loaded into a thermosensitive injectable hydrogel. Notably, the hydrogel exhibits obvious temperature sensitivity at a concentration of 6 wt %, and the nanoparticles possess concentration-dependent H2O2-response capability with a controlled release profile in 48 h. The combined strategy promoted the repair of injured peripheral nerves, attributed to the dual role of the materials, which mainly involved providing structural support, modulating the immune microenvironment, and enhancing angiogenesis. Overall, this study opens up intriguing prospects in tissue engineering.


Assuntos
Sistemas de Liberação de Medicamentos , Peróxido de Hidrogênio , Peróxido de Hidrogênio/farmacologia , Engenharia Tecidual , Hidrogéis/farmacologia , Hidrogéis/química , Nervos Periféricos/fisiologia , Regeneração Nervosa
16.
Nat Chem ; 16(5): 741-748, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38238464

RESUMO

Skeletal editing is a straightforward synthetic strategy for precise substitution or rearrangement of atoms in core ring structures of complex molecules; it enables quick diversification of compounds that is not possible by applying peripheral editing strategies. Previously reported skeletal editing of common arenes mainly relies on carbene- or nitrene-type insertion reactions or rearrangements. Although powerful, efficient and applicable to late-stage heteroarene core structure modification, these strategies cannot be used for skeletal editing of pyridines. Here we report the direct skeletal editing of pyridines through atom-pair swap from CN to CC to generate benzenes and naphthalenes in a modular fashion. Specifically, we use sequential dearomatization, cycloaddition and rearomatizing retrocycloaddition reactions in a one-pot sequence to transform the parent pyridines into benzenes and naphthalenes bearing diversified substituents at specific sites, as defined by the cycloaddition reaction components. Applications to late-stage skeletal diversification of pyridine cores in several drugs are demonstrated.

17.
ACS Omega ; 9(2): 2911-2919, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38250367

RESUMO

This study investigated the evolution of furnace conditions during the heat conversion process of multisource organic solid waste. To achieve this, combustion tests involving different sludge mixing ratios, variable load operation, and multisource organic solid waste collaborative disposal were performed on a 750 t/d new municipal solid waste incineration grate furnace. The test results revealed that as the sludge mixing ratios increased from 0 to 10 and 20%, the temperature level in the furnace decreased and the fuel-type NOx emission increased. Moreover, the sludge featured poor combustion stability under low-load conditions owing to fluctuations in its calorific value and moisture content. Field tests of multisource organic solid waste revealed that after mixing waste cloth strips and papermaking waste, the temperature level in the furnace increased. Additionally, the emissivity distribution was positively correlated with the furnace flame temperature distribution, and NOx emissions also increased. The overall results indicated the feasibility of controlling the mixing rate of different organic solid wastes in the municipal solid waste incinerator within a reasonable range for cooperative incineration.

18.
Opt Express ; 32(1): 825-834, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38175102

RESUMO

The diffraction efficiency, defined as the ratio of diffracted power to incident power, is one of the key working indicators for a computer-generated hologram (CGH). The CGH with high diffraction efficiency could suppress stray light and eliminate ghost images, thus improving interferometric performance in aspherical testing of low-reflectivity or large off-axis distance surfaces. However, the high-efficiency CGH is hard to precisely fabricate by traditional reactive ion etching and focusing ion beam, because it requires high etching depth with a high uniformity and sub-nanometric roughness in the glass, especially in the fabrication of a large CGH with an aperture of up to 300 mm. In this study, fabrication of the above-mentioned CGH was demonstrated via what we believe to be a new method called scanning homogenization etching (SHE), in which the ion source with a Gaussian energy distribution accurately scans the glass surface to realize homogenization etching. Different from controlling dwell time at each etching point, this paper proposes to control the scanning rate to achieve not only uniform but also quantitative depth removal in a single scan. Moreover, the depth errors in deep etching across the whole glass surface can be remarkably reduced due to homogenization effects introduced by multiple scanning etching. Finally, the target etching depth of 692.3 nm with an etching uniformity of 2.2% in the etching of a 300 mm CGH was achieved. The roughness of the etched and unetched area both have Ra values of 0.3 nm. The diffraction efficiency of working order is 39.998%, achieving 98.6% of the theoretical diffraction efficiency. In addition, the SHE is not limited by the aperture of the ion source, so it can achieve even larger diffractive optical elements with high diffraction efficiency and high accuracy.

19.
Zhongguo Gu Shang ; 37(1): 21-6, 2024 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-38286447

RESUMO

OBJECTIVE: To investigate the clinical effect of modified suspension reduction method combined with percutaneous vertebroplasty in the treatment of osteoporotic thoracolumbar compression fractures. METHODS: From February 2020 to October 2021, 92 patients with thoracolumbar osteoporotic compression fracture were treated by percutaneous vertebroplasty. According to different treatment methods, they were divided into the observation group and the control group. The observation group was treated with modified suspension reduction and then percutaneous vertebroplasty, while the control group was treated with percutaneous vertebroplasty alone. The observation group (47 cases), including 20 males and 27 females, the age ranged from 59 to 76 years old with an average of (69.74±4.50) years old, fractured vertebral bodies:T10(2 cases), T11(7 cases), T12(19 cases), L1(14 cases), L2(5 cases);the control group(45 cases), including 21 males and 24 females, the age ranged from 61 to 78 years old with an average of (71.02±3.58) years old, fractured vertebral bodies:T10(3 cases), T11(8 cases), T12(17 cases), L1(12 cases), L2(5 cases);The leakage of bone cement were observed, the visual analogue scale (VAS), Oswestry lumbar dysfunction index (ODI), anterior vertebrae height (AVH), Cobb angle of kyphosis and the amount of bone cement injected before and after operation were recorded and compared between the two groups. RESULTS: All patients were followed up, ranged from 6 to10 with an average of (8.45±1.73) months. Two patients ocurred bone cement leakage in observation group and 3 patients in control group. AVH of observation group increased (P<0.05) and Cobb angle of injured vertebrae decreased (P<0.05). Cobb angle of injured vertebrae and AVH of the control group were not significantly changed (P>0.05). Cobb angle of injured vertebrae of the observation group was lower than that of control group (P<0.05) and AVH was higher than that of the control group (P<0.05). In the observation group, VAS before operation and 1 week, 3 and 6 months after operation respectively were(7.32±1.05) scores, (3.56±1.18) scores, (1.83±0.67) scores, (1.27±0.34) scores, and ODI were(40.12±14.69) scores, (23.76±10.19) scores, (20.15±6.39) scores, (13.45±3.46) scores. In the control group, VAS before operation and 1 week, 3 and 6 months after operation respectively were(7.11±5.26) scores, (3.82±0.68) scores, (1.94±0.88) scores, (1.36±0.52) scores, and ODI were(41.38±10.23) scores, (25.13±14.22) scores , (20.61±5.82) scores, (14.55±5.27) scores . The scores of VAS and ODI after operation were lower than those before operation (P<0.05), but there was no significant difference between the two groups (P<0.05). CONCLUSION: Modified suspension reduction method combined with PVP surgery for osteoporotic thoracolumbar compression fractures has achieved good clinical results, which can effectively relieve lumbar back pain, restore vertebral height, correct kyphosis, improve lumbar function and patients' quality of life.


Assuntos
Fraturas por Compressão , Cifose , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Vertebroplastia , Masculino , Feminino , Humanos , Pessoa de Meia-Idade , Idoso , Cimentos Ósseos/uso terapêutico , Vertebroplastia/métodos , Fraturas por Compressão/cirurgia , Qualidade de Vida , Resultado do Tratamento , Fraturas da Coluna Vertebral/cirurgia , Vértebras Lombares/cirurgia , Vértebras Lombares/lesões , Fraturas por Osteoporose/cirurgia , Cifose/cirurgia , Estudos Retrospectivos
20.
Adv Sci (Weinh) ; 11(7): e2306181, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38064159

RESUMO

Due to its ability to adapt to a variety of electromagnetic (EM) environments, the sensing-enabled metasurface has garnered significant attention. However, large-scale EM-field sensing to obtain more information is still very challenging. Here, an adaptive information metasurface is proposed to enable intelligent sensing and wave manipulating simultaneously or more specifically, to realize intelligent target localization and beam tracking adaptively. The metasurface is composed of an array of meta-atoms, and each is loaded with two PIN diodes and a sensing-channel structure, for polarization-insensitive and programmable beamforming and sensing. By controlling the state of the PIN diode, the proposed meta-atom has 1-bit phase response in the designed frequency band, while the sensing loss keeps higher than -10 dB for both "ON" and "OFF" states. Hence there is nearly no interaction between the beamforming and sensing modes. Experiments are conducted to show multiple functions of the metasurface, including intelligent target sensing and self-adaptive beamforming, and the measured results are in good agreement with the numerical simulations and theoretical calculations.

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