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1.
Nature ; 630(8015): 222-229, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38657677

RESUMO

Gamma delta (γδ) T cells, a unique T cell subgroup, are crucial in various immune responses and immunopathology1-3. The γδ T cell receptor (TCR), which is generated by γδ T cells, recognizes a diverse range of antigens independently of the major histocompatibility complex2. The γδ TCR associates with CD3 subunits, initiating T cell activation and holding great potential in immunotherapy4. Here we report the structures of two prototypical human Vγ9Vδ2 and Vγ5Vδ1 TCR-CD3 complexes5,6, revealing two distinct assembly mechanisms that depend on Vγ usage. The Vγ9Vδ2 TCR-CD3 complex is monomeric, with considerable conformational flexibility in the TCRγ-TCRδ extracellular domain and connecting peptides. The length of the connecting peptides regulates the ligand association and T cell activation. A cholesterol-like molecule wedges into the transmembrane region, exerting an inhibitory role in TCR signalling. The Vγ5Vδ1 TCR-CD3 complex displays a dimeric architecture, whereby two protomers nestle back to back through the Vγ5 domains of the TCR extracellular domains. Our biochemical and biophysical assays further corroborate the dimeric structure. Importantly, the dimeric form of the Vγ5Vδ1 TCR is essential for T cell activation. These findings reveal organizing principles of the γδ TCR-CD3 complex, providing insights into the unique properties of γδ TCR and facilitating immunotherapeutic interventions.


Assuntos
Complexo CD3 , Receptores de Antígenos de Linfócitos T gama-delta , Linfócitos T , Humanos , Complexo CD3/química , Complexo CD3/imunologia , Complexo CD3/metabolismo , Complexo CD3/ultraestrutura , Colesterol/metabolismo , Colesterol/química , Microscopia Crioeletrônica , Ligantes , Ativação Linfocitária/imunologia , Modelos Moleculares , Domínios Proteicos , Multimerização Proteica , Receptores de Antígenos de Linfócitos T gama-delta/química , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/ultraestrutura , Linfócitos T/química , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Transdução de Sinais , Membrana Celular/química , Membrana Celular/metabolismo
2.
Chemistry ; 30(10): e202302959, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38012090

RESUMO

A two-enzyme cascade system containing ω-transaminase (ω-TA) and L-threonine aldolase (L-ThA) was reported for the synthesis of 3-Phenylserine starting from benzylamine, and PLP was utilized as the only cofactor in these both two enzymes reaction system. Based on the transamination results, benzylamine was optimized as an advantageous amino donor as confirmed by MD simulation results. This cascade reaction system could not only facilitate the in situ removal of the co-product benzaldehyde, enhancing the economic viability of the reaction, but also establish a novel pathway for synthesizing high-value phenyl-serine derivatives. In our study, nearly 95 % of benzylamine was converted, yielding over 54 % of 3-Phenylserine under the optimized conditions cascade reaction.


Assuntos
Glicina Hidroximetiltransferase , Serina , Serina/análogos & derivados , Serina/metabolismo , Glicina Hidroximetiltransferase/metabolismo , Benzilaminas , Fosfato de Piridoxal
3.
Langmuir ; 40(26): 13467-13475, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38889438

RESUMO

Because of the deep and zigzag microporous structure, porous carbon materials exhibit inferior capacitive performance and sluggish electrochemical kinetics for supercapacitor electrode materials. Herein, a single-step carbonation and activation approach was utilized to synthesize coal-based porous carbon with an adjustable pore structure, using CaO as a hard template, KOH as an activator, and oxidized coal as precursors to carbon. The obtained sample possesses an interconnected and hierarchical porous structure, higher SSA (1060 m2 g-1), suitable mesopore volume (0.25 cm3 g-1), and abundant surface heteroatomic functional groups. Consequently, the synthesized carbon exhibits an exceptionally high specific capacitance of 323 F g-1 at 1 A g-1, along with 80.3% capacitance retention at 50 A g-1. The assembled two-electrode configuration demonstrates a remarkable capacitance retention of up to 95% and achieves Coulombic efficiency of nearly 100% with 10,000 cycles in a 6 M KOH electrolyte. Furthermore, the Zn-ion hybrid capacitor also exhibits a specific capacity of up to 139.1 mA h g-1 under conditions of 0.2 A g-1. This work offers a simple method in preparation of coal-based porous carbon with controllable pore structure.

4.
Lipids Health Dis ; 23(1): 187, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38907262

RESUMO

PURPOSE: The ratio of non-high-density lipoprotein cholesterol (non-HDL-c) to high-density lipoprotein cholesterol (HDL-c) (NHHR) is a novel comprehensive lipid index. The aim of this study was to investigate the relationship between the NHHR and the prevalence of hyperuricaemia (HUA) in the adult population of the U.S. METHODS: This cross-sectional study collected data from the National Health and Nutrition Examination Survey (NHANES) (2007-2018). HUA was defined as a serum uric acid (SUA) concentration ≥ 7 mg/dL in men and ≥ 6 mg/dL in women. Multivariate logistic regression models and the restricted cubic spline (RCS) method were applied to examine the relationship between the NHHR and the risk of developing HUA. Subgroup analyses and interaction tests were also performed. RESULTS: The prevalence of HUA increased with increasing NHHR values (9.01% vs. 13.38% vs. 17.31% vs. 25.79%, P < 0.001). The NHHR was independently correlated with the risk of developing HUA (OR = 1.10, 95% CI: 1.05-1.16; P < 0.001). Furthermore, the risk of developing HUA was significantly greater among individuals with the highest NHHR quartile than among those with the lowest NHHR quartile (OR = 1.94, 95% CI: 1.62-2.33; P < 0.001). This relationship was consistent across subgroups. According to the RCS analysis, an inverted U-shaped relationship existed between the NHHR and the risk of developing HUA. CONCLUSIONS: The NHHR was closely associated with an increased risk of developing HUA. Further studies on the NHHR could be beneficial for preventing and treating HUA.


Assuntos
HDL-Colesterol , Hiperuricemia , Ácido Úrico , Humanos , Hiperuricemia/sangue , Hiperuricemia/epidemiologia , Feminino , Masculino , HDL-Colesterol/sangue , Pessoa de Meia-Idade , Adulto , Estudos Transversais , Ácido Úrico/sangue , Inquéritos Nutricionais , Fatores de Risco , Prevalência , Idoso , LDL-Colesterol/sangue , Modelos Logísticos
5.
Langmuir ; 39(19): 6865-6873, 2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37133428

RESUMO

Porous carbon, one of the characteristic materials for electrochemical energy storage devices, has been paid wide-ranging attention. However, balancing the reconcilable mesopore volume with a large specific surface area (SSA) was still a challenge. Herein, a dual-salt-induced activation strategy was developed to obtain a porous carbon sheet with ultrahigh SSA (3082 m2 g-1), desirable mesopore volume (0.66 cm3 g-1), nanosheet morphology, and high surface O (7.87%) and S (4.0%) content. Hence, as a supercapacitor electrode, the optimal sample possessed a high specific capacitance (351 F g-1 at 1 A g-1) and excellent rate performance (holding capacitance up to 72.2% at 50 A g-1). Furthermore, the assembled zinc-ion hybrid supercapacitor also exhibited superior reversible capacity (142.7 mAh g-1 at 0.2 A g-1) and highly stable cycling (71.2 mAh g-1 at 5 A g-1 after 10,000 cycles with retention of 98.9%). This work was delivered a new possibility for the development of coal resources for the preparation of high performance porous carbon materials.

6.
Langmuir ; 39(49): 18073-18081, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38014689

RESUMO

The defective BiOCl nanosheet exposed (001) facet with favorable photocatalytic performance was designed. The surface microstructure analysis and theoretical calculation certified the dominant exposed (001) facet and rich surface oxygen defects of Br--doped BiOCl (B-6) nanosheets. The energy level structure analysis indicates that the band gap can be narrowed and the light absorption range can be widened by introducing Br- to BiOCl, and the presence of defective energy levels increases the photogenerated carrier transfer efficiency. Moreover, the doping of Br- in BiOCl promotes the directional flow of electrons to the surface of B-6, which improves the photocatalytic performance of the sample. Thus, the Br--doped BiOCl can degrade 96.5% RhB within 6 min under visible-light irradiation with high apparent reaction rate constants of 0.51 min-1, exhibiting the strongest photocatalytic degradation performance. This work provides guidance for the preparation of Bi-based photocatalysts with excellent performance.

7.
J Nanobiotechnology ; 21(1): 16, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36647125

RESUMO

BACKGROUND: Oral administration offered a painless way and improved compliance for diabetics. However, the emerging GLP-1 analog peptide drugs for diabetes primarily rely on the injection route, and the development of oral dosage forms was hampered by the low oral bioavailability due to the structural vulnerability to digestive enzymes and molecule impermeability in the gastrointestinal tract. RESULTS: In this study, the non-covalent interaction between cholic acid (CA) and liraglutide (LIRA) was found and theoretically explained by molecular docking simulation. Formation of this physical complex of liraglutide and cholic acid (LIRA/CA Complex) reduced the self-aggregation of LIRA and accelerated intestinal epithelium penetration. By the anti-solvent method, LIRA/CA Complex was loaded into zein/rhamnolipids nanoparticles (LIRA/CA@Zein/RLs) with a loading efficiency of 76.8%. LIRA was protected from fast enzymatic degradation by the hydrophobic zein component. Meanwhile, Rhamnolipids, a glycolipid with surface activity, promoted endocytosis while also stabilizing the nanoparticles. The two components worked synergistically to ensure the delivery of LIRA/CA Complex to intestinal villi and improved oral absorption without disrupting tight junctions. LIRA/CA@Zein/RLs demonstrated a considerable intestinal epithelium absorption in mouse gastrointestinal section and a retention in vivo over 24 h, resulting in a significant and long-lasting hypoglycemic effect in Type 2 diabetes mice. CONCLUSION: This study provided a promising oral delivery approach for LIRA and exhibited the potential for further translation into clinical application.


Assuntos
Diabetes Mellitus Tipo 2 , Nanocompostos , Zeína , Camundongos , Animais , Liraglutida/farmacologia , Zeína/química , Ácido Cólico , Simulação de Acoplamento Molecular , Hipoglicemiantes/farmacologia , Glicolipídeos , Mucosa Intestinal
8.
Sensors (Basel) ; 23(13)2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37448039

RESUMO

Multiple unmanned aerial vehicles (UAVs) have a greater potential to be widely used in UAV-assisted IoT applications. UAV formation, as an effective way to improve surveillance and security, has been extensively of concern. The leader-follower approach is efficient for UAV formation, as the whole formation system needs to find only the leader's trajectory. This paper studies the leader-follower surveillance system. Owing to different scenarios and assignments, the leading velocity is dynamic. The inevitable communication time delays resulting from information sending, communicating and receiving process bring challenges in the design of real-time UAV formation control. In this paper, the design of UAV formation tracking based on deep reinforcement learning (DRL) is investigated for high mobility scenarios in the presence of communication delay. To be more specific, the optimization UAV formation problem is firstly formulated to be a state error minimization problem by using the quadratic cost function when the communication delay is considered. Then, the delay-informed Markov decision process (DIMDP) is developed by including the previous actions in order to compensate the performance degradation induced by the time delay. Subsequently, an extended-delay informed deep deterministic policy gradient (DIDDPG) algorithm is proposed. Finally, some issues, such as computational complexity analysis and the effect of the time delay are discussed, and then the proposed intelligent algorithm is further extended to the arbitrary communication delay case. Numerical experiments demonstrate that the proposed DIDDPG algorithm can significantly alleviate the performance degradation caused by time delays.


Assuntos
Algoritmos , Inteligência , Cadeias de Markov , Políticas , Registros
9.
Molecules ; 28(13)2023 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-37446628

RESUMO

To reduce the issue of tri-primary color reabsorption, a new approach for single-phase phosphors as light-emitting diodes (LEDs) has been recommended. The structures, morphology, photoluminescence, thermal stability, and luminescence mechanism of a variety of Ca3Bi (PO4)3 (CBPO): Ce3+/Dy3+ phosphors were investigated. XRD characterization showed that all CBPO samples were eulytite structures. Furthermore, the energy transfer process from Ce3+ to Dy3+ in CBPO is systematically investigated in this work, and the color of light can be adjusted by changing the ratio of doped ions. Under UV light, energy is transferred from Ce3+-Dy3+ mainly through quadrupole-quadrupole interactions in the CBPO host, and doping with different Dy3+ concentrations tunes the emission color from blue to white. The thermal stability of the CBPO: 0.04Ce3+, 0.08Dy3+ samples is outstanding, and the CIE coordinates of the samples after emission have little effect with temperature, while their emission intensity at 423 K is as strong as that at room temperature, reaching 90%. The above results indicate that this CBPO material has great potential as a white light phosphor under near-UV excitation at the optimized concentration of Ce3+ and Dy3+.


Assuntos
Disprósio , Luminescência , Disprósio/química , Raios Ultravioleta , Transferência de Energia , Temperatura
10.
Molecules ; 28(9)2023 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-37175070

RESUMO

The surface properties and the hierarchical pore structure of carbon materials are important for their actual application in supercapacitors. It is important to pursue an integrated approach that is both easy and cost-effective but also challenging. Herein, coal-based hierarchical porous carbon with nitrogen doping was prepared by a simple dual template strategy using coal as the carbon precursor. The hierarchical pores were controlled by incorporating different target templates. Thanks to high conductivity, large electrochemically active surface area (483 m2 g-1), hierarchical porousness with appropriate micro-/mesoporous channels, and high surface nitrogen content (5.34%), the resulting porous carbon exhibits a high specific capacitance in a three-electrode system using KOH electrolytes, reaching 302 F g-1 at 1 A g-1 and 230 F g-1 at 50 A g-1 with a retention rate of 76%. At 250 W kg-1, the symmetrical supercapacitor assembled at 6 M KOH shows a high energy density of 8.3 Wh kg-1, and the stability of the cycling is smooth. The energy density of the symmetric supercapacitor assembled under ionic liquids was further increased to 48.3 Wh kg-1 with a power output of 750 W kg-1 when the operating voltage was increased to 3 V. This work expands the application of coal-based carbon materials in capacitive energy storage.

11.
Angew Chem Int Ed Engl ; 62(44): e202311549, 2023 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-37715322

RESUMO

Both hydrogen (H2 ) and copper ions (Cu+ ) can be used as anti-cancer treatments. However, the continuous generation of H2 molecules and Cu+ in specific sites of tumors is challenging. Here we anchored Cu2+ on carbon photocatalyst (Cu@CDCN) to allow the continuous generation of H2 and hydrogen peroxide (H2 O2 ) in tumors using the two-electron process of visible water splitting. The photocatalytic process also generated redox-active Cu-carbon centers. Meanwhile, the Cu2+ residues reacted with H2 O2 (the obstacle to the photocatalytic process) to accelerate the two-electron process of water splitting and cuprous ion (Cu+ ) generation, in which the Cu2+ residue promoted a pro-oxidant effect with glutathione through metal-reducing actions. Both H2 and Cu+ induced mitochondrial dysfunction and intracellular redox homeostasis destruction, which enabled hydrogen therapy and cuproptosis to inhibit cancer cell growth and suppress tumor growth. Our research is the first attempt to integrate hydrogen therapy and cuproptosis using metal-enhanced visible solar water splitting in nanomedicine, which may provide a safe and effective cancer treatment.


Assuntos
Carbono , Cobre , Humanos , Transformação Celular Neoplásica , Hidrogênio , Água , Apoptose
12.
Angew Chem Int Ed Engl ; 62(27): e202303482, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37129053

RESUMO

Although large amount of effort has been invested in combating thermal quenching that severely degrades the performance of luminescent materials particularly at high temperatures, not much affirmative progress has been realized. Herein, we demonstrate that the Frenkel defect formed via controlled annealing of Sc2 (WO4 )3 :Ln (Ln=Yb, Er, Eu, Tb, Sm), can work as energy reservoir and back-transfer the stored excitation energy to Ln3+ upon heating. Therefore, except routine anti-thermal quenching, thermally enhanced 415-fold downshifting and 405-fold upconversion luminescence are even obtained in Sc2 (WO4 )3 :Yb/Er, which has set a record of both the Yb3+ -Er3+ energy transfer efficiency (>85 %) and the working temperature at 500 and 1073 K, respectively. Moreover, this design strategy is extendable to other hosts possessing Frenkel defect, and modulation of which directly determines whether enhanced or decreased luminescence can be obtained. This discovery has paved new avenues to reliable generation of high-temperature luminescence.

13.
J Viral Hepat ; 29(6): 438-446, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35357759

RESUMO

Several hepatitis B virus (HBV) serum markers have been identified as risk factors for liver fibrosis in patients with chronic HBV infection, and several noninvasive fibrosis tests based on serum indexes are now used to identify the severity of liver fibrosis. We aimed to identify the relationship between hepatitis B core-related antigen (HBcrAg) serum levels and liver fibrosis in treatment-naive chronic HBV infection patients. A total of 246 treatment-naive chronic HBV infection patients were enrolled in this study. All of the patients underwent liver biopsies at baseline. Using the METAVIR fibrosis stages, there were 15, 140, 50, 26 and 15 patients in the F0, F1, F2, F3 and F4 stages (METAVIR scoring system), respectively. The biochemical, serological and virological parameters were measured using standard laboratory procedures. The HBcrAg serum levels of the patients were examined via ELISA. HBcrAg serum levels of F2, F3 and F4 stage patients were significantly higher than those of nonsignificant liver fibrosis patients (METAVIR F0-F1), but there were no significant differences among F2, F3 and F4 stage patients. Serum HBcrAg (OR, 2.18; 95% confidence interval [CI], 1.51-3.16), albumin (ALB) (OR, 0.60; 95% CI, 0.41-0.87), prothrombin activity (PTA) (OR, 0.58; 95% CI, 0.40-0.83) and platelet (PLT) counts (OR, 0.38; 95% CI, 0.25-0.57) were associated with significant liver fibrosis (METAVIR F2-F4). The serum HBcrAg value enabled the correct identification of patients with significant fibrosis, with an area under the receiver operating characteristic curve of 0.81 (95% CI, 0.75-0.88). The APRI, FIB-4 index and ALBI score can identify significant liver fibrosis with an area under the ROC curve of 0.74 (95% CI, 0.66-0.81), 0.73 (95% CI, 0.65-0.80) and 0.63 (95% CI, 0.55-0.72), respectively. Compared with these three indexes, the accuracy rate of diagnosis of significant fibrosis based on HBcrAg was higher than that of the FIB-4 index (p = 0.0479) and ALBI score (p = 0.0030). HBcrAg, ALB, PTA serum levels and PLT counts were associated with significant liver fibrosis in treatment-naive chronic HBV infection patients. HBcrAg serum levels enabled the correct identification of patients with significant fibrosis (METAVIR F2-F4), and HBcrAg was more effective than the FIB-4 index and ALBI score.


Assuntos
Vírus da Hepatite B , Hepatite B Crônica , Biomarcadores , Antígenos do Núcleo do Vírus da Hepatite B , Humanos , Fígado/patologia , Cirrose Hepática/patologia , Estudos Retrospectivos
14.
J Nanobiotechnology ; 20(1): 427, 2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36175957

RESUMO

Primary liver cancer has become the second most fatal cancer in the world, and its five-year survival rate is only 10%. Most patients are in the middle and advanced stages at the time of diagnosis, losing the opportunity for radical treatment. Liver cancer is not sensitive to chemotherapy or radiotherapy. At present, conventional molecularly targeted drugs for liver cancer show some problems, such as short residence time, poor drug enrichment, and drug resistance. Therefore, developing new diagnosis and treatment methods to effectively improve the diagnosis, treatment, and long-term prognosis of liver cancer is urgent. As an emerging discipline, nanobiotechnology, based on safe, stable, and efficient nanomaterials, constructs highly targeted nanocarriers according to the unique characteristics of tumors and further derives a variety of efficient diagnosis and treatment methods based on this transport system, providing a new method for the accurate diagnosis and treatment of liver cancer. This paper aims to summarize the latest progress in this field according to existing research and the latest clinical diagnosis and treatment guidelines in hepatocellular carcinoma (HCC), as well as clarify the role, application limitations, and prospects of research on nanomaterials and the development and application of nanotechnology in the diagnosis and treatment of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Nanoestruturas , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/tratamento farmacológico , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/tratamento farmacológico , Nanoestruturas/uso terapêutico , Medicina de Precisão , Prognóstico
15.
Sleep Breath ; 26(3): 1011-1022, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-34657273

RESUMO

PURPOSE: Many studies have shown that chitinase-3-like protein 1 (CHI3L1), also known as YKL-40, is associated with asthma. The purpose of this meta-analysis was to evaluate the role of serum YKL-40 in the diagnosis and differential diagnosis of asthma, severity grading, and determination of disease state. METHODS: The PubMed, Ovid, and Cochrane databases were searched. A total of 17 articles involving 5696 subjects were included in this meta-analysis. RESULTS: The results showed that the level of YKL-40 was significantly higher in asthmatic patients than in the normal group regardless of age and residential location, and increased with severity and acute exacerbation (p < 0.05). YKL-40 levels were significantly different between chronic obstructive pulmonary disease (COPD) and asthma, and also between asthma-COPD overlap syndrome (ACO) and asthma (p < 0.05). CONCLUSION: YKL-40 may act as a potential serological marker for the diagnosis of asthma, assessment of severity, indicator of the disease state, and differential diagnosis of COPD, ACO, and asthma.


Assuntos
Asma , Proteína 1 Semelhante à Quitinase-3/sangue , Doença Pulmonar Obstrutiva Crônica , Biomarcadores , Diagnóstico Diferencial , Humanos
16.
Int J Mol Sci ; 23(12)2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35743296

RESUMO

Carbon monoxide (CO) oxidation performance heavily depends on the surface-active species and the oxygen vacancies of nanocomposites. Herein, the CuOx/Cu1.5Mn1.5O4 were fabricated via solid-state strategy. It is manifested that the construction of CuOx/Cu1.5Mn1.5O4 nanocomposite can produce abundant surface CuOx species and a number of oxygen vacancies, resulting in substantially enhanced CO oxidation activity. The CO is completely converted to carbon dioxide (CO2) at 75 °C when CuOx/Cu1.5Mn1.5O4 nanocomposites were involved, which is higher than individual CuOx, MnOx, and Cu1.5Mn1.5O4. Density function theory (DFT) calculations suggest that CO and O2 are adsorbed on CuOx/Cu1.5Mn1.5O4 surface with relatively optimal adsorption energy, which is more beneficial for CO oxidation activity. This work presents an effective way to prepare heterogeneous metal oxides with promising application in catalysis.


Assuntos
Nanocompostos , Oxigênio , Catálise , Cobre
17.
Entropy (Basel) ; 24(2)2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35205598

RESUMO

With the rapid development of UAV technology, the research of optimal UAV formation tracking has been extensively studied. However, the high maneuverability and dynamic network topology of UAVs make formation tracking control much more difficult. In this paper, considering the highly dynamic features of uncertain time-varying leader velocity and network-induced delays, the optimal formation control algorithms for both near-equilibrium and general dynamic control cases are developed. First, the discrete-time error dynamics of UAV leader-follower models are analyzed. Next, a linear quadratic optimization problem is formulated with the objective of minimizing the errors between the desired and actual states consisting of velocity and position information of the follower. The optimal formation tracking problem of near-equilibrium cases is addressed by using a backward recursion method, and then the results are further extended to the general dynamic case where the leader moves at an uncertain time-varying velocity. Additionally, angle deviations are investigated, and it is proved that the similar state dynamics to the general case can be derived and the principle of control strategy design can be maintained. By using actual real-world data, numerical experiments verify the effectiveness of the proposed optimal UAV formation-tracking algorithm in both near-equilibrium and dynamic control cases in the presence of network-induced delays.

18.
Angew Chem Int Ed Engl ; 61(45): e202212089, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36102873

RESUMO

Different from organic dye/quantum dot possessing one luminescent center, upconversion luminescence (UCL) is actually a statistic of temporal behaviors of countless individual activators. Our experimental results have shown that the rise and decay dynamics of UCL is directly associated with the relative contribution of sensitizer-to-activator energy transfer and energy migration among sensitizers, which can be physically modulated by simply tuning the excitation laser. Therefore, dynamic UCL with record-wide 20-fold lifetime, ≈70-fold red-to-green intensity ratio, and reversibly definable emission color is easily realized by just modulating the excitation laser. Moreover, this generally applicable strategy only requires a simplest-possible UCL system whereas prevalent material engineering such as complicated composition design, sophisticated core-shell construction, or tedious chemical synthesis, is no longer needed.

19.
BMC Womens Health ; 21(1): 266, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34225734

RESUMO

BACKGROUND: Premenstrual dysphoric disorder (PMDD) is a common, recently recognized, psychiatric condition among reproductive women, reflecting abnormal responsivity to ovarian steroids. Moreover, the potential organizational effect of prenatal sex hormones during PMDD has got attentions, but there have been considerably less of researches on this topic. The aim of this research was to investigate the possible role of prenatal androgen in the PMDD. METHODS: Anogenital distance (AGD), the distance between a woman's clitoris and her urethral meatus (CUMD), left and right 2D:4D ratios were measured in 77 subjects (25 patients with PMDD), as these anthropometric indicators are considered to indirectly reflect prenatal androgen exposures in utero. RESULTS: Patients with PMDD had a longer CUMD than controls (25.03 ± 4.73 vs. 22.07 ± 4.30, P = 0.008), while there were no significant difference between PMDD group and control group in the AGD and right and left 2D:4D ratios. CONCLUSION: Atypical high prenatal androgen exposure might predispose individuals to be susceptible to PMDD.


Assuntos
Transtorno Disfórico Pré-Menstrual , Síndrome Pré-Menstrual , Clitóris , Feminino , Humanos , Ovário , Gravidez , Esteroides , Uretra
20.
Respiration ; 97(4): 355-362, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30544115

RESUMO

BACKGROUND: Most of the patients on noninvasive positive pressure ventilation require aerosol inhalation therapy to moisturize the airways or deliver drugs in acute settings. However, the effect of jet nebulization on noninvasive positive pressure ventilation (NPPV) has not been determined. OBJECTIVES: This study was designed to investigate the impact of jet nebulization on NPPV applied in ventilators. METHODS: Aerosol therapy during NPPV was conducted in a simulated lung. The jet nebulizer was connected at both the distal and proximal end of the exhalation valve for the noninvasive ventilators, while it was placed both in front of the Y tube proximal to the patient and at 15 cm distance from the Y-tube inspiratory limb distal to the patient for the intensive care unit (ICU) ventilators. Driving flow was set at 4 and 8 L/min, respectively. RESULTS: TPmin (time from the beginning of the lung simulator's inspiratory effort to the lowest value of airway pressure needed to trigger the ventilator), Ttrig (time to trigger), and Ptrig (the magnitude of airway pressure drop needed to trigger) were not significantly altered by jet nebulization in the noninvasive ventilators, while they were significantly increased in the ICU ventilators. The greater the driving flow, the stronger the impact on TPmin, Ttrig, and Ptrig. The actual tidal volume and control performance were not significantly affected by jet nebulization in either noninvasive or ICU ventilators. The tidal volume monitored was significantly increased at 8 L/min driving flow. The greater the driving flow, the stronger the impact on the tidal volume monitored. CONCLUSION: The effect of jet nebulization on NPPV was different when compared to invasive ventilation. Jet nebulization only affected the tidal volume monitored in the noninvasive ventilator. Jet nebulization also affected the triggering performance and tidal volume monitored in the ICU ventilator.


Assuntos
Administração por Inalação , Respiração com Pressão Positiva , Ventiladores Mecânicos , Cuidados Críticos , Unidades de Terapia Intensiva , Volume de Ventilação Pulmonar
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