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1.
Appl Opt ; 63(4): 999-1006, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38437397

RESUMO

In this paper, we investigate the energy efficiency optimization for a parallel relay-assisted underwater wireless optical communication (UWOC) system with simultaneous lightwave information and power transfer (SLIPT) over an aggregate channel. In this system, relay nodes are equipped with energy harvesting devices, getting energy from the direct current component of the received signal transmitted by the source node. These nodes utilize the harvested energy to transmit the signal to the destination node with the decoding and forwarding strategy. The harvested energy for each relay node is derived by the Gauss-Laguerre quadrature formula and the outage probability is deduced by the Meijer-G function. Then, the system's energy efficiency can be calculated and an energy efficiency maximization problem is built up with respect to the bias current. We propose a three-level-iteration algorithm to solve this problem. In the first level, the Dinkelbach method is used to represent energy efficiency in a parametric subtractive form. In the second level, we use the penalty function method to convert the object function and constraint. In the third level, the objective function is transformed into a quadratic function by using a successive convex approximate method, thereby solving for the bias current. The effects of system parameters on energy efficiency are also analyzed. Theoretical results and Monte Carlo simulations suggest that employing the solved bias current can significantly improve the system's energy efficiency.

2.
Sensors (Basel) ; 24(10)2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38794050

RESUMO

Reverberation in real environments is an important factor affecting the high resolution of target sound source localization (SSL) methods. Broadband low-frequency signals are common in real environments. This study focuses on the localization of this type of signal in reverberant environments. Because the time reversal (TR) method can overcome multipath effects and realize adaptive focusing, it is particularly suitable for SSL in a reverberant environment. On the basis of the significant advantages of the sparse Bayesian learning algorithm in the estimation of wave direction, a novel SSL is proposed in reverberant environments. First, the sound propagation model in a reverberant environment is studied and the TR focusing signal is obtained. We then use the sparse Bayesian framework to locate the broadband low-frequency sound source. To validate the effectiveness of the proposed method for broadband low-frequency targeting in a reverberant environment, simulations and real data experiments were performed. The localization performance under different bandwidths, different numbers of microphones, signal-to-noise ratios, reverberation times, and off-grid conditions was studied in the simulation experiments. The practical experiment was conducted in a reverberation chamber. Simulation and experimental results indicate that the proposed method can achieve satisfactory spatial resolution in reverberant environments and is robust.

3.
Molecules ; 29(11)2024 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-38893496

RESUMO

A novel low-density composite for the absorption of microwaves was prepared by loading La-doped spinel cobalt ferrite (La-CFO) onto biomass carbon (BC) derived from corn stalks using a hydrothermal method. This composite (La-CFO@BC) not only maintained the advantageous properties of low density and abundant porosity, but also exhibited a unique morphology, with La-CFO displaying a carpet-like structure interspersed with dandelion-shaped particles. The incorporation of La-CFO effectively tuned the electromagnetic parameters of the composite, thereby improving its impedance-matching attributes and its ability to absorb microwave radiation. At a frequency of 12.8 GHz for electromagnetic waves and with a thickness of 2.5 mm, La-CFO@BC demonstrated remarkable performance in microwave absorption, attaining a noteworthy minimum reflection (RLmin) of -53.2 dB and an effective absorption bandwidth (EAB) of 6.4 GHz. Furthermore, by varying the thickness of the La-CFO@BC within the range of 1.0 to 5.5 mm, the EAB could be broadened to 13.8 GHz, covering the entire X-band, the entire Ku-band, and a substantial portion of the C-band. This study demonstrated that La-CFO@BC was a promising alternative for electromagnetic wave attenuation, which offered superior performance in microwave absorption.

4.
Curr Issues Mol Biol ; 45(10): 8013-8026, 2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37886949

RESUMO

Concurrent chemoradiotherapy is an effective treatment option for patients with low-grade colorectal cancer (CRC) in the local disease stage. At present, the principle of the Taiwan Medical Center is to treat CRC patients with combination radiotherapy and chemotherapy (high-dose 5-FU) for a period of about five weeks prior to surgery. Radical resection of the tumor is performed at least six to eight weeks after concurrent chemoradiotherapy (CCRT). However, this approach fails to produce the desired therapeutic effect in approximately 20% to 30% of patients, and such patients are unnecessarily exposed to the risks of radiation and drug toxicity posed by this therapy. Therefore, it is crucial to explore new biomarkers to predict the prognosis of CRC. SUMO-activating enzyme subunit 1 (SAE1) plays an important role in SUMOylation, a post-translational modification involved in cellular functions, such as cell proliferation, cell cycle, and apoptosis. In our study, to explore the clinical-pathological role of SAE1 protein in CRC, we evaluated the clinical data and paraffin sections from CRC patients. The expression of SAE1 was evaluated using immunohistochemical analysis, and clinical parameters were analyzed using chi-square and Kaplan-Meier survival tests. The results of in vitro proliferation and radiosensitive assays were compared between control groups and SAE1 siRNA groups. Western blotting was also used to detect the expressions of the SAE1, PARP, cyclin D1, p-NF-κB, and NF-κB proteins. Flow cytometry and colony formation assays were used to detect the effect of SAE-1 on radiosensitivity. In vivo, we detected the growth curve in a mouse xenograft model. The results showed that SAE-1 was revealed to be an independent prognostic biomarker of CRC. SAE1 knockdown inhibited CRC proliferation in vitro and in vivo, and led to the cleavage of PARP, downregulation of cyclin D1 protein expression, and downregulation of p-NF-κB/NF-κB. Additionally, SAE1 knockdown promoted radiosensitivity in CRC cells. Therefore, it was inferred that SAE1 may be used as a potential therapeutic target in CRC treatment.

5.
J Endovasc Ther ; : 15266028231168352, 2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37154346

RESUMO

OBJECTIVE: To report demographics and clinical, laboratory, and imaging features of acute renal infarction (ARI) due to symptomatic isolated spontaneous renal artery dissection (SISRAD) and to analyze outcomes after the initial therapy for SISRAD. METHODS: Thirteen patients with ARI due to SISRAD between January 2016 and March 2021 were enrolled in this retrospective study. We reviewed the demographics, clinical, laboratory, and imaging features (location of the infarct kidney, the branch artery involved by dissection, true lumen stenosis, false lumen thrombosis, and aneurysm), treatment modalities, and follow-up results; analyzed the difference between SISRAD and other causes of ARI; and propose an appropriate therapy strategy for SISRAD based on our data and literature. RESULT: Patients with ARI due to SISRAD were mostly young men (43 [24-53] years; 12/13 [92%]). No patients had atrial fibrillation or acute kidney injury at admission (0/13). All 13 patients received conservative treatment as the initial treatment. Sixty-two percent (8/13) of patients progressed, and 88% (7/8) of them had dissection aneurysm on the admission computed tomographic angiography (CTA) image. Seventy-five percent (6/8) of patients underwent endovascular intervention as follows, stent placement in 1 patient, renal artery embolization in 1, and stent placement with embolization in 4. Two patients with disease progression died: 1 during the conservative treatment period and 1 after the stent placement. Thirty-eight percent (5/13) of patients in remission continued to receive conservative treatment, none of whom had dissection aneurysm on the admission CTA. CONCLUSION: Symptomatic isolated spontaneous renal artery dissection is a rare and fatal disease. For young ARI patients with no previous history of tumors and cardiogenic diseases, CTA examination is recommended to exclude SISRAD. Dissection aneurysm seems to be a risk of progression for SISRAD in this series. Conservative treatment, a recognized initial treatment, has a good effect on patients without dissection aneurysm, and we recommend endovascular intervention as the initial treatment for the patient with dissection aneurysm at admission. Multicenter clinical studies are needed to explore a more-appropriate treatment for patients with SISRAD. CLINICAL IMPACT: This article report the related factors, risks, demographics and laboratory data of Acute renal infarction (ARI) due to Symptomatic isolated spontaneous renal artery dissection (SISRAD) and explore a better initial therapy strategy for SISRAD. It will help improve the effectiveness of SISRAD treatment and reduce the mortality rate from this rare but lethal disease.

6.
Inorg Chem ; 62(5): 1864-1874, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-35830693

RESUMO

By incorporating photoreactive anthracene moieties into binuclear Dy2O2 motifs, we obtain two new compounds with the formulas [Dy2(SCN)4(L)2(dmpma)4] (1) and [Dy2(SCN)4(L)2(dmpma)2(CH3CN)2] (2), where HL is 4-methyl-2,6-dimethoxyphenol and dmpma is dimethylphosphonomethylanthracene. Compound 1 contains face-to-face π-π interacted anthracene groups that meet the Schmidt rule for a [4 + 4] photocycloaddition reaction, while stacking of the anthracene groups in compound 2 does not meet the Schmidt rule. Compound 1 undergoes a reversible single-crystal-to-single-crystal structural transformation upon UV-light irradiation and thermal annealing, forming a one-dimensional coordination polymer of [Dy2(SCN)4(L)2(dmpma)2(dmpma2)]n (1UV). The process is concomitant with changes in the magnetic dynamics and photoluminescent properties. The spin-reversal energy barrier is significantly increased from 1 (55.9 K) to 1UV (116 K), and the emission color is changed from bright yellow for 1 to weak blue for 1UV. This is the first binuclear lanthanide complex that exhibits synergistic photocontrollable magnetic dynamics and photoluminescence. Ab initio calculations are conducted to understand the magnetostructural relationships of compounds 1, 1UV, and 2.

7.
J Phys Chem A ; 127(14): 3088-3095, 2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-36988266

RESUMO

Theoretical investigations on mixed-valence dilanthanide complexes (CpiPr5)2Ln2I3 (Ln = Tb, Dy, and Ho) indicate that the total spin of the 4f shell couples preferentially to the σ electron spin and then to the orbital angular momentum, improving the strength of spin-orbit coupling (SOC) for each magnetic center. On the other hand, the concentration of negative charges containing the delocalized σ electron in the axial direction leads to a large crystal-field (CF) splitting. Both strong SOC and large CF splitting lead to the largest energy barrier Ueff of such complexes up to now. In addition, our calculations show that the introduction of σ electron can better suppress the quantum tunneling of magnetization in the ground spin-orbit state, and the Ueff of (CpiPr5)2Ln2I3 is expected to originate from the contribution of both Ln ions under such strong Ln-σ exchange coupling.

8.
Sensors (Basel) ; 23(9)2023 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-37177390

RESUMO

Automatic modulation classification (AMC) plays an important role in intelligent wireless communications. With the rapid development of deep learning in recent years, neural network-based automatic modulation classification methods have become increasingly mature. However, the high complexity and large number of parameters of neural networks make them difficult to deploy in scenarios and receiver devices with strict requirements for low latency and storage. Therefore, this paper proposes a lightweight neural network-based AMC framework. To improve classification performance, the framework combines complex convolution with residual networks. To achieve a lightweight design, depthwise separable convolution is used. To compensate for any performance loss resulting from a lightweight design, a hybrid data augmentation scheme is proposed. The simulation results demonstrate that the lightweight AMC framework reduces the number of parameters by approximately 83.34% and the FLOPs by approximately 83.77%, without a degradation in performance.

9.
Entropy (Basel) ; 25(11)2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37998216

RESUMO

Quantum obfuscation is one of the important primitives in quantum cryptography that can be used to enhance the security of various quantum cryptographic schemes. The research on quantum obfuscation focuses mainly on the obfuscatability of quantum functions. As a primary quantum function, the quantum power function has led to the development of quantum obfuscation because it is applicable to construct new obfuscation applications such as quantum encryption schemes. However, the previous definition of quantum power functions is constrained and cannot be beneficial to the further construction of other quantum functions. Thus, it is essential to extend the definition of the basic quantum power function in a more general manner. In this paper, we provide a formal definition of two quantum power functions called generalized quantum power functions with coefficients, each of which is characterized by a leading coefficient and an exponent that corresponds to either a quantum or classical state, indicating the generality. The first is the quantum power function with a leading coefficient, and the second is the quantum n-th power function, which are both fundamental components of quantum polynomial functions. In addition, obfuscation schemes for the functions are constructed by quantum teleportation and quantum superdense coding, and demonstrations of their obfuscatability are also provided in this paper. This work establishes the fundamental basis for constructing more quantum functions that can be utilized for quantum obfuscation, therefore contributing to the theory of quantum obfuscation.

10.
Pak J Pharm Sci ; 36(1): 89-97, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36967501

RESUMO

Development of adjuvant chemotherapy drugs against drug-resistant lung cancer cells is necessary. The use of non-toxic adjuvant natural product combined with chemotherapy drugs will be an important treatment mode in the future. The purpose of the study investigates that fucoidan enhances chemotherapy drug poisoning drug-resistant lung cancer cell. Drug-resistant lung cancer cells are established in the study. Cell culture, MTT assay, wound healing assay, gelatin zymography assay, DNA fragmentation assay, apoptosis assay, reverse transcription polymerase chain reaction (RT-PCR) western blot analysis was adopted. The results showed that fucoidan synergized with doxorubicin increased efficacy of poisoning drug-resistant lung cancer cells and enhanced the ability of doxorubicin to inhibit the migration of drug-resistant lung cancer cells. It was observed that fucoidan synergized with doxorubicin induced the increase of apoptosis and inhibited expression of MMP-9, LC3, Beclin-1 and ß-catenin in drug-resistant lung cancer cells. Fucoidan synergized with doxorubicin significantly inhibited proliferation, migration and metastasis of drug-resistant lung cancer cells. Fucoidan strengthened doxorubicin to induce apoptosis and autophagy of drug-resistant lung cancer cells. This study confirms that the combined use of fucoidan and chemotherapeutic drugs can effectively poison drug-resistant lung cancer cells.


Assuntos
Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Apoptose , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêutico , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Proliferação de Células , Linhagem Celular Tumoral
11.
Opt Express ; 30(22): 39492-39509, 2022 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-36298900

RESUMO

In this paper, we investigate joint subchannel assignment and power allocation for the energy efficiency (EE) optimization in an indoor visible light communication (VLC)-Internet of Things (IoT) system with simultaneous lightwave information and power transfer (SLIPT). A mixed-integer fractional nonlinear programming problem that is challenging to solve is formulated. To tackle this problem, the optimal transmission scheme is decomposed into subchannel assignment and power allocation. Firstly, a virtual cell formation and subchannel assignment (VCF-SA) scheme is proposed, which considers the location of IoT devices, quality of service requirements, and energy states. Secondly, a quadratic transformation-based power allocation (QTBPA) scheme is designed to transform the fractional nonlinear programming problem into a series of convex problems that can be solved iteratively. Simulation results illustrate the effectiveness of the proposed scheme in terms of system EE compared to the benchmarks. The impact of system parameters on the EE is also analyzed.

12.
J Endovasc Ther ; : 15266028221112254, 2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35852451

RESUMO

OBJECTIVES: Endovascular treatment (EVT) is an alternative method used to treat isolated dissection of the celiac artery (IDCA). However, only a few mid-term results have been reported. This study aimed to analyze and compare the outcomes of endovascular and non-operative therapies for IDCA. METHODS: Data from a cohort of consecutive IDCA patients enrolled in the study hospital between April 2012 and September 2020 were retrospectively reviewed. Demographic information, imaging features, treatment modalities, and follow-up results of celiac artery remodeling and adverse events were collected and analyzed. RESULTS: A total of 87 patients were enrolled in the study. Stents were deployed in 68 patients, and non-operative treatment (blood pressure control and pain management) was continued in the remaining 19 patients who did not receive stenting; among these 19 patients, EVT failed in 6. The mean follow-up period was 37.3 (range, 10-85 months) and 44.0 (range, 9-80 months) months in the EVT and non-operative groups, respectively. During follow-up, the overall complete remodeling (absence of residual dissection with no false lumen or no intramural thrombus) rate was significantly higher in the EVT group than in the non-operative group (87.3% vs 7.1%, p<0.001). The incomplete remodeling (improved true lumen with malabsorption or partial thrombosis of the false lumen) rate was not significantly different between the EVT and non-operative groups (6.3% vs 14.3%; p=0.2984). Meanwhile, the adverse event-free survival rates were 89.0%, 67.0%, and 67.0% at 1, 3, and 5 years, respectively, in the EVT group compared with 39.7% and 29.8% at 1 and 3 years in the non-operative group (p<0.0001). CONCLUSIONS: EVT for IDCA may be considered an effective management option with a favorable clinical success rate, an encouraging complete remodeling rate, and a satisfactory adverse event-free survival rate. However, further evaluation with a long-term follow-up is required. CLINICAL IMPACT: Endovascular intervention for isolated dissection of the celiac artery has attracted inadequate attention. In this retrospective study with comparative analysis of endovascular versus conservative therapy for isolated dissection of the celiac artery patients, a better complete remodeling rate and a higher adverse event-free survival rate were observed in the endovascular treatment (EVT) group during follow-up, indicating that EVT could be an effective management option for isolated dissection of the celiac artery.

13.
Cochrane Database Syst Rev ; 9: CD014703, 2022 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-36074662

RESUMO

BACKGROUND: Spontaneous isolated dissection of the superior mesenteric artery (SIDSMA) occurs when a tear in the inner layer of the superior mesenteric artery (SMA) allows blood to flow between the layers of the SMA, forcing the layers apart, and creating two lumens. Abdominal pain is the most prevalent clinical manifestation. Other people may have no symptoms or experience nausea, vomiting, diarrhea, or blood in their stools. For people with SIDSMA who are not suspected of intestinal necrosis or intra-abdominal bleeding, medical treatment and endovascular therapy are the main treatment options. There is no consensus on the optimum first-line management strategy. OBJECTIVES: To evaluate the benefits and harms of endovascular therapy versus medical treatment for spontaneous isolated dissection of the superior mesenteric artery (SIDSMA). SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 3 August 2021. SELECTION CRITERIA: We planned to include all randomized controlled trials (RCTs) which compared endovascular therapy and medical treatments for SIDSMA. We planned to exclude studies where participants were treated with open surgery. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were endovascular intervention rate and recurrent abdominal pain. Our secondary outcomes were open surgery rate, remodeling rate of SMA, new aneurysm formation of SMA, SMA occlusion, new dissection of SMA, death, symptom relief rate and complications of endovascular therapy. We planned to use GRADE to assess certainty of evidence for each outcome. MAIN RESULTS: We did not identify any RCTs to include in any analysis. AUTHORS' CONCLUSIONS: We were not able to include any RCTs that compared endovascular therapy versus medical treatment in people with SIDSMA. High-quality RCTs that evaluate the benefits and harms of these interventions are needed to help determine the optimal strategy for managing SIDSMA.


Assuntos
Dissecção Aórtica , Procedimentos Endovasculares , Dor Abdominal/etiologia , Dor Abdominal/terapia , Dissecção Aórtica/cirurgia , Procedimentos Endovasculares/métodos , Humanos , Artéria Mesentérica Superior/cirurgia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
14.
Appl Opt ; 61(17): 5090-5097, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-36256187

RESUMO

We propose an instantaneous frequency measurement (IFM) scheme featured with unambiguous measurement utilizing a Sagnac loop with an embedded bi-directional phase modulator and an optical filter with a linear frequency response. The frequency of the microwave signal to be measured is instantaneously estimated by calculating an amplitude comparison function (ACF) of photocurrents from the upper and lower branches of the proposed structure. Compared to previous IFM schemes, the ACF in the proposed scheme is monotonic, by which the frequency of the unknown microwave signal can be uniquely confirmed without ambiguity. Only one laser source and a phase modulator are needed, which simplifies the measurement system. In addition, the monotonous ACF can guarantee measurement accuracy in a wide range, from low frequency to high frequency. The IFM system has robustness in optical and RF power shifts. Simulation results show that frequency measurement over the range of 30 GHz with a measurement error of 0.4 GHz is achieved.

15.
Lab Invest ; 101(9): 1142-1152, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34103662

RESUMO

Numerous studies have revealed that hyperglycemia is a pivotal driver of diabetic vascular complications. However, the mechanisms of hyperglycemia-induced endothelial dysfunction in diabetes remain incompletely understood. This study aims to expound on the underlying mechanism of the endothelial dysfunction induced by hyperglycemia from the perspective of long non-coding RNAs (lncRNA). In this study, a downregulation of SNHG15 was observed in the ischemic hind limb of diabetic mice and high glucose (HG)-treated HUVECs. Functionally, the overexpression of SNHG15 promoted cell proliferation, migration, and tube formation, and suppressed cell apoptosis in HG-treated HUVECs. Mechanistically, SNHG15 reduced thioredoxin-interacting protein (TXNIP) expression by enhancing ITCH-mediated ubiquitination of TXNIP. TXNIP overexpression abrogated the protective effect of lncRNA SNHG15 overexpression on HG-induced endothelial dysfunction. The following experiment further confirmed that SNHG15 overexpression promoted angiogenesis of the ischemic hind limb in diabetic mice. In conclusion, SNHG15 is a novel protector for hyperglycemia-induced endothelial dysfunction via decreasing TXNIP expression.


Assuntos
Proteínas de Transporte , Hiperglicemia/metabolismo , RNA Longo não Codificante , Tiorredoxinas , Ubiquitinação/genética , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Células Cultivadas , Diabetes Mellitus Experimental/metabolismo , Células Endoteliais/citologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Tiorredoxinas/genética , Tiorredoxinas/metabolismo
16.
J Vasc Res ; 58(5): 311-320, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33882503

RESUMO

BACKGROUND: Pathogenesis of cardiovascular diseases begins with endothelial dysfunction. Our previous study has shown that advanced glycation end products (AGE) could inhibit the expression of homeobox A9 (Hoxa9), thereby inducing endothelial dysfunction. Leucine-rich repeat flightless-interacting protein 1 (LRRFIP1) has been found to participate in a variety of pathological processes, but reports of its role in endothelial dysfunction are rare. OBJECTIVES: This study aims to investigate whether LRRFIP1 is involved in AGE-induced endothelial dysfunction through Hoxa9-mediated transcriptional activation. METHODS: Chromatin immunoprecipitation was used to detect the transcriptional regulation of Hoxa9 on LRRFIP1 promoters. Human umbilical vein endothelial cells were treated with AGE or pyrrolidinedithiocarbamate (nuclear factor kappa-B [NF-κB] inhibitor). Moreover, changes in apoptosis, proliferation, migration, release of nitric oxide, and angiogenesis were detected. RESULTS: Hoxa9 promotes LRRFIP1 expression by binding to the -LRRFIP1 promoter. Meanwhile, overexpression of LRRFIP1 inhibited phosphorylation of P65 and elevated expression of Hoxa9. Overexpression of LRRFIP1 or/and Hoxa9 reversed the effects of AGE on HUVEC. AGE-induced inhibition on the expression of LRRFIP1 and Hoxa9 could be reversed by the NF-κB inhibitor. CONCLUSION: LRRFIP1 is involved in AGE-induced endothelial dysfunction via being regulated by the NF-κB/Hoxa9 axis.


Assuntos
Células Endoteliais/efeitos dos fármacos , Produtos Finais de Glicação Avançada/toxicidade , Proteínas de Homeodomínio/metabolismo , NF-kappa B/metabolismo , Neovascularização Fisiológica/efeitos dos fármacos , Proteínas de Ligação a RNA/metabolismo , Soroalbumina Bovina/toxicidade , Apoptose/efeitos dos fármacos , Sítios de Ligação , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Proteínas de Homeodomínio/genética , Células Endoteliais da Veia Umbilical Humana , Humanos , NF-kappa B/antagonistas & inibidores , Fosforilação , Regiões Promotoras Genéticas , Pirrolidinas/farmacologia , Proteínas de Ligação a RNA/genética , Transdução de Sinais , Tiocarbamatos/farmacologia , Fator de Transcrição RelA/metabolismo , Ativação Transcricional
17.
Arterioscler Thromb Vasc Biol ; 40(7): 1705-1721, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32268790

RESUMO

OBJECTIVE: A decrease in nitric oxide, leading to vascular smooth muscle cell proliferation, is a common pathological feature of vascular proliferative diseases. Nitric oxide synthesis by eNOS (endothelial nitric oxide synthase) is precisely regulated by protein kinases including AKT1. ENH (enigma homolog protein) is a scaffolding protein for multiple protein kinases, but whether it regulates eNOS activation and vascular remodeling remains unknown. Approach and Results: ENH was upregulated in injured mouse arteries and human atherosclerotic plaques and was associated with coronary artery disease. Neointima formation in carotid arteries, induced by ligation or wire injury, was greatly decreased in endothelium-specific ENH-knockout mice. Vascular ligation reduced AKT and eNOS phosphorylation and nitric oxide production in the endothelium of control but not ENH-knockout mice. ENH was found to interact with AKT1 and its phosphatase PHLPP2 (pleckstrin homology domain and leucine-rich repeat protein phosphatase 2). AKT and eNOS activation were prolonged in VEGF (vascular endothelial growth factor)-induced ENH- or PHLPP2-deficient endothelial cells. Inhibitors of either AKT or eNOS effectively restored ligation-induced neointima formation in ENH-knockout mice. Moreover, endothelium-specific PHLPP2-knockout mice displayed reduced ligation-induced neointima formation. Finally, PHLPP2 was increased in the endothelia of human atherosclerotic plaques and blood cells from patients with coronary artery disease. CONCLUSIONS: ENH forms a complex with AKT1 and its phosphatase PHLPP2 to negatively regulate AKT1 activation in the artery endothelium. AKT1 deactivation, a decrease in nitric oxide generation, and subsequent neointima formation induced by vascular injury are mediated by ENH and PHLPP2. ENH and PHLPP2 are thus new proatherosclerotic factors that could be therapeutically targeted.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Lesões das Artérias Carótidas/enzimologia , Artéria Carótida Primitiva/enzimologia , Proteínas dos Microfilamentos/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Remodelação Vascular , Proteínas Adaptadoras de Transdução de Sinal/deficiência , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Aterosclerose/enzimologia , Aterosclerose/patologia , Aterosclerose/fisiopatologia , Lesões das Artérias Carótidas/genética , Lesões das Artérias Carótidas/patologia , Lesões das Artérias Carótidas/fisiopatologia , Artéria Carótida Primitiva/patologia , Artéria Carótida Primitiva/fisiopatologia , Células Cultivadas , Doença da Artéria Coronariana/enzimologia , Doença da Artéria Coronariana/patologia , Doença da Artéria Coronariana/fisiopatologia , Modelos Animais de Doenças , Células Endoteliais da Veia Umbilical Humana/enzimologia , Humanos , Proteínas com Domínio LIM/genética , Proteínas com Domínio LIM/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas dos Microfilamentos/deficiência , Proteínas dos Microfilamentos/genética , Neointima , Óxido Nítrico/metabolismo , Fosfoproteínas Fosfatases/deficiência , Fosfoproteínas Fosfatases/genética , Fosforilação , Transdução de Sinais
18.
Ann Vasc Surg ; 77: 280-287, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34411679

RESUMO

BACKGROUND: To evaluate the quality of in vitro fenestrations during in situ fenestration (ISF) and investigate the differences between needle and laser puncture in current stent-grafts. METHODS: An in vitro study evaluated the damage created by needle ISF on stent-graft fabrics versus laser ISF. Fenestrations were made in 5 different commercially available stent-grafts, including polyester stent-grafts (Relay, Valiant and Hercules) and expanded polytetrafluoroethylene (ePTFE) stent-grafts (TAG and Ankura). Each stent-graft received fenestration by needle and laser separately, followed by gradual dilation (4 mm, 6 mm, 8 mm, and 10 mm sequentially) of noncompliant balloons. Quantitative and qualitative evaluations including fenestration diameter, area, shape and margins were conducted using light microscopy and scanning electron microscope. RESULTS: The primary fenestrations created by needle were slit-like with visible cut-off fibers in polyester stent-grafts and were almost circular with clear margins in ePTFE stent-grafts; those created by laser were squared or elliptical with ragged edges and burned fibers in all the stent-grafts. Fabric debris and toxic particles due to burning of the material were generated during laser-assisted fenestration. The Primary holes in polyester stent-grafts (Relay, Valiant and Hercules) by needle showed smaller area (0.05 mm2 vs. 0.22 mm2, 0.52 mm2 vs. 0.70 mm2 and 0.28 mm2 vs. 0.46 mm2; P < 0.01) and worse shape (0.93 vs. 2.46, 1.17 vs. 2.33 and 0.93 vs. 2.47; P < 0.01) than those by laser, while larger area (0.67 vs.0.43, 0.59 vs.0.45; P < 0.05), better shape (3.93 vs. 2.53, 3.90 vs. 2.93; P < 0.05) and better margin (3.83 vs. 2.47, 3.83 vs. 2.53; P < 0.05) in ePTFE stent-grafts (TAG and Ankrura). After gradual balloon dilation, the final holes showed no evident difference in maximal length, fenestration area, scores of shape and margin between the 2 ways of fenestration (P > 0.05). Ankura stent-graft showed the largest holes with best quality than the others. CONCLUSIONS: The primary fenestrations were different between needle and laser puncture, laser induced fabric debris and toxic particles release should be cautiously considered. The final fenestrations were similar after gradual balloon dilation.


Assuntos
Angioplastia com Balão/instrumentação , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Lasers , Agulhas , Desenho de Prótese , Stents , Humanos , Poliésteres/química , Politetrafluoretileno/química
19.
Appl Opt ; 60(12): 3482-3486, 2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33983255

RESUMO

The optical approach to estimate the direction-of-arrival (DOA) estimation of microwave signals has attracted a lot of attention recently. Most of the existing methods are based on a one-sensor array system, which converts the DOA estimation problem into an optical power estimation problem. Their main disadvantage is that additional work is needed to represent the relationship between the phase shifts and the optical powers before estimation. The algorithm proposed in this paper is based on an N-sensor array (N>2), where the optical power vector is obtained first and then a compressive sensing-based approach is applied to directly estimate the phase shift. As demonstrated by simulation results, the proposed algorithm can achieve much better estimation accuracy and robustness than existing optical DOA estimation algorithms considered.

20.
Opt Express ; 28(15): 21627-21640, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32752436

RESUMO

This paper investigates a downlink power allocation scheme for application of non-orthogonal multiple access (NOMA) in visible light communication (VLC) systems. Aiming to achieve a flexible tradeoff between sum rate and user fairness depending on administrators' subjective setting and acquire the optimal solution for any setting, we formulate two optimization problems, which are closely aligned with the practical application. Specifically, one is user fairness-guaranteed sum rate maximization, the other is sum rate-guaranteed user fairness maximization. Moreover, through classified discussion around the threshold guaranteeing user fairness or sum rate, we present rigorous mathematical derivation and optimization analysis, and two corresponding algorithms are proposed. Furthermore, through numerical simulation, the superiority of our proposed algorithms over conventional schemes is verified in terms of meeting the practical demand and performance gain in sum rate, user fairness, and coverage probability.

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