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1.
Parasitol Res ; 123(4): 189, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38639821

RESUMO

Toxocara canis is a parasitic zoonose that is distributed worldwide and is one of the two pathogens causing toxocariasis. After infection, it causes serious public health and safety problems, which pose significant veterinary and medical challenges. To better understand the regulatory effects of T. canis infection on the host immune cells, murine macrophages (RAW264.7) were incubated with recombinant T. canis C-type lectin 4 (rTc-CTL-4) protein in vitro. The quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were used to analyze the nucleotide-binding oligomerization domain-containing protein 1/2 (NOD1/2), receptor-interacting protein 2 (RIP2), nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB), and mitogen-activated protein kinase (MAPK) on mRNA level and protein expression level in macrophages. Our results indicated that 10 µg/mL rTc-CTL-4 protein could modulate the expression of NOD1, NOD2, and RIP2 at both the transcriptional and translational levels. The protein translation levels of NF-κB, P-p65, p38, and P-p38 in macrophages were also modulated by rTc-CTL-4 protein. Macrophages were co-incubated with rTc-CTL-4 protein after siRNA silencing of NOD1, NOD2, and RIP2. The expression levels of NF-κB, P-p65, p38, and P-p38 were significantly changed compared with the negative control groups (Neg. Ctrl.). Taken together, rTc-CTL-4 protein seemed to act on NOD1/2-RIP2-NF-κB and MAPK signaling pathways in macrophages and might activate MAPK and NF-κB signaling pathways by regulating NOD1, NOD2, and RIP2. The insights from the above studies could contribute to our understanding of immune recognition and regulatory mechanisms of T. canis infection in the host animals.


Assuntos
NF-kappa B , Toxocara canis , Animais , Camundongos , NF-kappa B/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Toxocara canis/metabolismo , Transdução de Sinais/fisiologia , Macrófagos
2.
Sci Rep ; 14(1): 6537, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38503891

RESUMO

The rapid growth of artificial intelligence is revolutionizing classical engineering society, offering novel approaches to material and structural design and analysis. Among various scientific machine learning techniques, physics-informed neural network (PINN) has been one of the most researched subjects, for its ability to incorporate physics prior knowledge into model training. However, the intrinsic continuity requirement of PINN demands the adoption of domain decomposition when multiple materials with distinct properties exist. This greatly complicates the gradient computation of design features, restricting the application of PINN to structural shape optimization. To address this, we present a novel framework that employs neural network coordinate projection for shape optimization within PINN. This technique allows for direct mapping from a standard shape to its optimal counterpart, optimizing the design objective without the need for traditional transition functions or the definition of intermediate material properties. Our method demonstrates a high degree of adaptability, allowing the incorporation of diverse constraints and objectives directly as training penalties. The proposed approach is tested on magnetostatic problems for iron core shape optimization, a scenario typically plagued by the high permeability contrast between materials. Validation with finite-element analysis confirms the accuracy and efficiency of our approach. The results highlight the framework's capability as a viable tool for shape optimization in complex material design tasks.

3.
Oncogene ; 43(18): 1353-1368, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38459120

RESUMO

Undifferentiated pleomorphic sarcoma (UPS) is a highly aggressive malignant soft tissue tumor with a poor prognosis; however, the identity and heterogeneity of tumor populations remain elusive. Here, eight major cell clusters were identified through the RNA sequencing of 79,569 individual cells of UPS. UPS originates from mesenchymal stem cells (MSCs) and features undifferentiated subclusters. UPS subclusters were predicted to exist in two bulk RNA datasets, and had a prognostic value in The Cancer Genome Atlas (TCGA) dataset. The functional heterogeneity of malignant UPS cells and the immune microenvironment were characterized. Additionally, the fused cells were innovatively detected by expressing both monocyte/macrophage markers and other subcluster-associated genes. Based on the ligand-receptor interaction analysis, cellular interactions with epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) were abundant. Furthermore, 73% of patients with UPS (48/66) showed positive EGFR expression, which was associated with a poor prognosis. EGFR blockade with cetuximab inhibited tumor growth in a patient-derived xenograft model. Our transcriptomic studies delineate the landscape of UPS intratumor heterogeneity and serve as a foundational resource for further discovery and therapeutic exploration.


Assuntos
Receptores ErbB , Sarcoma , Análise de Célula Única , Humanos , Animais , Receptores ErbB/genética , Receptores ErbB/metabolismo , Camundongos , Sarcoma/patologia , Sarcoma/genética , Prognóstico , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia , Ensaios Antitumorais Modelo de Xenoenxerto , Cetuximab/farmacologia , Cetuximab/uso terapêutico , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica
4.
Opt Express ; 32(2): 2539-2553, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38297780

RESUMO

Synthetic aperture Ladar (SAL) is an extension of synthetic aperture technology in the optical frequency band. Owing to the short wavelength of lasers, the system has high-resolution, high-data-rate, and refined imaging capabilities, which has potential in high-resolution observation fields such as ground observation and space target observation. However, the short wavelength of lasers also makes SAL severely sensitive to vibrations even on the micron order which cause azimuth defocusing and range cell migration. To address this problem, we establish a de-chirp signal model under vibration environment, and propose a vibration error estimation and compensation method using triangular interferometric signals. According to the symmetrical characteristics of triangular frequency modulated continuous wave (T-FMCW) and the time-frequency information introduced by the azimuthal vibration phase, we use a two-stage interferometry method to estimate instantaneous frequency introduced by the vibration errors that cause range cell migration. For the scenarios without obvious range cell migration, we use a one-stage interferometry method to estimate the instantaneous frequency. Subsequently, we establish a vibration compensation filter using the estimated instantaneous frequency to compensate for the vibration errors. We use two experiments to verify the effectiveness and superiority of the proposed method. The results show that the proposed method effectively eliminates range cell migration and azimuthal phase errors introduced by vibration errors, producing SAL imaging results with higher resolution than the conventional spectral correlation method.

5.
Environ Sci Pollut Res Int ; 31(5): 8046-8060, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38175516

RESUMO

Earth pressure balance (EPB) shield is increasingly employed in metro tunnel construction, and causes a series of environmental, safety, and resource waste problems due to the disposal of a considerable amount of muck. In situ recycling of EPB shield muck is an effective solution, whereas the foam is generated by residual foaming agents used as the muck conditioning material during tunnelling, which often adsorbs clay particles and overflows the flocculation tank. To achieve defoaming and antifoaming during the reuse of muck, this study prepared novel eco-friendly silicone oil-polyether defoamers by condensation, compounding, and shear emulsification. Defoaming and antifoaming performances of different defoamers were tested using a modified Ross-Miles method and a scale model of field flocculation systems. The results indicated that a high efficiency in defoam and antifoam was characterized by chemical grafting of nano-SiO2 from silicone oils, uniform distribution and large size of grains, low viscosity, and surface tension. The defoamer dosage of 0.002-0.004 wt% near critical micelle concentration (CMC) for each defoamer is reasonable. Overall, the prepared hydroxyl silicone oil-glycerol polyoxypropylene ether (H-G) defoamer compared with other silicone oil-polyether defoamers and commercial defoamers presents the highest defoaming and antifoaming efficiency. Considering the effects of EPB shield muck, the H-G defoamer is least affected by the compound materials and increasing concentration of the commercial foaming agent. Nevertheless, the stability of the H-G emulsion system is weaker than that of the dimethyl silicone oil-glycerol polyoxypropylene ether (D-G) emulsion system after 1 month of sealed storage.


Assuntos
Antiespumantes , Polímeros , Propilenoglicóis , Óleos de Silicone , Antiespumantes/química , Antiespumantes/farmacologia , Óleos de Silicone/química , Emulsões/química , Glicerol , Tensoativos , Éteres
6.
Small ; : e2307309, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38150611

RESUMO

Ferroptosis is associated with the occurrence and development of many diseases, which is the result of an imbalance in cellular metabolism and oxidation-reduction balance. Therefore, it is an effective therapeutic strategy that simultaneously regulating the intracellular oxidation-reduction system. Herein, a click reaction of alkynylamide with thiol groups in the presence of amine or in PBS (pH = 7.4) is developed, which can react efficiently with thiol substances, such as cysteine (Cys), glutathione (GSH), and bovine serum albumin (BSA). Notably, MBTB-PA, an aggregation-induced emission (AIE) photosensitizer with an alkynylamide unit, is synthesized and its intracellular behavior is visualized in situ by fluorescence imaging, demonstrating its excellent ability to target the endoplasmic reticulum. Furthermore, MBTB-PA reacted with proteins in tumor cells, consumed reducing substances, and triggered intracellular oxidative stress, resulting in cell death. Based on this reaction therapy strategy, click reaction is combined with photodynamic therapy to achieve effective killing of tumor cells by simultaneously raising the intracellular oxidative state and reducing the reductive state. This work not only develops an application of click reaction of alkynamide with thiol in bioconjugation and anti-tumor therapy, but also provides feasible ideas for organic reactions in the exploration of organisms.

7.
Cancer Med ; 2023 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-38102873

RESUMO

BACKGROUND: Visceral sarcoma is a rare malignancy with a poor prognosis. However, there is no recommended prognostic staging system for the malignant disease. METHOD: We analyzed the data of patients diagnosed with primary soft tissue sarcoma (STS) of the abdomen and thoracic visceral organs between 2006 and 2017 at our hospital. Prognostic factors (size, tumor grade, and lymph node metastasis) were analyzed in our cohort (n = 203) and the SEER validation cohort (n = 5826). RESULTS: Tumor size, grade, and lymph node metastasis were important prognostic factors for visceral sarcoma in both our and the SEER cohorts. Based on these prognostic factors, we established a new staging system for visceral sarcoma, by which patients could be stratified into clinically meaningful and non-overlapping stages in both our cohort and the SEER validation series. Moreover, the area under the curve (AUC) value of the staging system for 5-year survival was 0.84 (95% CI: 0.78-0.89) in our series and 0.80 (95% CI: 0.79-0.81) in SEER series, respectively. In addition, compared with the widely used FIGO staging system for female genital sarcoma, the visceral sarcoma staging system could more effectively and reliably stratify patients into four different prognostic groups. CONCLUSIONS: The visceral sarcoma staging system is applicable for STS of the abdomen and thoracic visceral organs and is better than the current FIGO staging system for female genital sarcoma and should be incorporated into the AJCC Cancer Staging Manual.

8.
Angew Chem Int Ed Engl ; 62(41): e202311099, 2023 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-37639670

RESUMO

Mononuclear nonheme iron(II) and 2-oxoglutarate (Fe/2OG)-dependent oxygenases and halogenases are known to catalyze a diverse set of oxidative reactions, including hydroxylation, halogenation, epoxidation, and desaturation in primary metabolism and natural product maturation. However, their use in abiotic transformations has mainly been limited to C-H oxidation. Herein, we show that various enzymes of this family, when reconstituted with Fe(II) or Fe(III), can catalyze Mukaiyama hydration-a redox neutral transformation. Distinct from the native reactions of the Fe/2OG enzymes, wherein oxygen atom transfer (OAT) catalyzed by an iron-oxo species is involved, this nonnative transformation proceeds through a hydrogen atom transfer (HAT) pathway in a 2OG-independent manner. Additionally, in contrast to conventional inorganic catalysts, wherein a dinuclear iron species is responsible for HAT, the Fe/2OG enzymes exploit a mononuclear iron center to support this reaction. Collectively, our work demonstrates that Fe/2OG enzymes have utility in catalysis beyond the current scope of catalytic oxidation.


Assuntos
Ferro , Oxigenases , Oxigenases/metabolismo , Ferro/metabolismo , Ácidos Cetoglutáricos/metabolismo , Oxirredução , Catálise , Hidrogênio
9.
Opt Express ; 31(9): 13585-13600, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37157243

RESUMO

Optical aberrations of optical systems cause significant degradation of imaging quality. Aberration correction by sophisticated lens designs and special glass materials generally incurs high cost of manufacturing and the increase in the weight of optical systems, thus recent work has shifted to aberration correction with deep learning-based post-processing. Though real-world optical aberrations vary in degree, existing methods cannot eliminate variable-degree aberrations well, especially for the severe degrees of degradation. Also, previous methods use a single feed-forward neural network and suffer from information loss in the output. To address the issues, we propose a novel aberration correction method with an invertible architecture by leveraging its information-lossless property. Within the architecture, we develop conditional invertible blocks to allow the processing of aberrations with variable degrees. Our method is evaluated on both a synthetic dataset from physics-based imaging simulation and a real captured dataset. Quantitative and qualitative experimental results demonstrate that our method outperforms compared methods in correcting variable-degree optical aberrations.

10.
Bioact Mater ; 23: 223-233, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36439086

RESUMO

The research on pharmacology usually focuses on the structure-activity relationships of drugs, such as antibiotics, to enhance their activity, but often ignores their optical properties. However, investigating the photophysical properties of drugs is of great significance because they could be used to in situ visualize their positions and help us to understand their working metabolism. In this work, we identified a class of commercialized antibiotics, such as levofloxacin, norfloxacin, and moxifloxacin (MXF) hydrochloride, featuring the unique aggregation-induced emission (AIE) characteristics. By taking advantage of their AIE feature, antibiotic metabolism in cells could be in situ visualized, which clearly shows that the luminescent aggregates accumulate in the lysosomes. Moreover, after a structure-activity relationship study, we found an ideal site of MXF to be modified with a triphenylphosphonium and an antibiotic derivative MXF-P was prepared, which is able to specifically differentiate bacterial species after only 10 min of treatment. Moreover, MXF-P shows highly effective broad-spectrum antibacterial activity, excellent therapeutic effects and biosafety for S. aureus-infected wound recovery. Thus, this work not only discovers the multifunctionalities of the antibiotics but also provides a feasible strategy to make the commercialized drugs more powerful.

11.
Cancer Med ; 12(3): 2722-2730, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35984371

RESUMO

BACKGROUND: Fine-needle aspiration (FNA) cytology is a rapid, inexpensive, and uncomplicated method. However, its role in the assessment of soft tissue lesions (STL) remains controversial, and its ability to guide surgical treatment remains unclear. This study investigated the positive predictive value (PPV) of FNA for detecting malignancy and its guiding role in the surgical treatment of STL. METHODS: We retrospectively reviewed 514 patients with STL who underwent preoperative FNA and surgical resection between March 2015 and August 2021. Imaging assessments confirmed that radical surgery was possible. The FNA results were compared with the final postoperative histopathology. RESULTS: Of the 514 patients with STL, 496 (mean age, 48.9 years; range, 21-91 years) were eligible for analysis, the male to female ratio was 111:100. According to the 496 FNA results, 90 (18.2%) were positive for malignancy, 84 (16.9%) were suspicious for malignancy, 80 (16.1%) were spindle cell present, and 242 (48.8%) were negative for malignant cells. Compared with postoperative histopathology, FNA correctly detected all 90 malignant lesions and 203 of the 242 benign lesions. A total of 39 false-negative results were obtained. FNA showed an accuracy of 88.3%, sensitivity of 69.8%, specificity of 100%, negative predictive value (NPV) of 83.9%, and PPV of 100%. In the other seven validation cohorts (n = 1157), FNA had a consistently high PPV, with values all more than 93%. CONCLUSION: Our results demonstrate that FNA has a high PPV for detecting malignancy. For patients with resectable lesions and malignant FNA, the core needle biopsy (CNB) step can be omitted with multidisciplinary evaluation, and subsequent radical surgery can be performed.


Assuntos
Neoplasias , Adulto , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Biópsia por Agulha Fina/métodos , Estudos Retrospectivos , Sensibilidade e Especificidade , China , Biópsia com Agulha de Grande Calibre
12.
ACS Appl Bio Mater ; 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36112526

RESUMO

It is well-known that bacterial infections will induce a variety of diseases in the clinic. In particular, the emergence of drug-resistant bacteria has increased the threat to human health. The development of multiple modes of therapy will effectively fight against drug-resistant bacterial infections. In this work, we covalently attached an AIE photosensitizer to the antibiotic of moxifloxacin hydrochloride (MXF-HCl) and synthesized an antibiotic derivative, MXF-R, with pharmacological activity and photodynamic activation. In infected cells, MXF-R showed enhanced fluorescence after it specifically binds to bacteria; thus, in situ visualization of the bacteria was realized. Notably, through chemo- and photodynamic therapy, MXF-R exhibited better antibacterial activity than its parent antibiotic in rapid sterilization, and it achieved effective killing for moxifloxacin resistant bacteria. In addition, MXF-R shows a broad-spectrum antibacterial effect and could be used in the recovery therapy of infected wounds in mice, demonstrative of a significant therapeutic effect and good biological safety. Thus, as a promising multifunctional antibacterial agent, MXF-R will have tremendous potential in in situ visualization study and killing of drug-resistant bacteria. This work provides an innovative strategy for solving critical disease through the combination of materials and biomedical sciences.

13.
ACS Nano ; 16(6): 9479-9497, 2022 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-35713471

RESUMO

Oral infectious diseases and tooth staining, the main challenges of dental healthcare, are inextricably linked to microbial colonization and the formation of pathogenic biofilms. However, dentistry has so far still lacked simple, safe, and universal prophylactic options and therapy. Here, we report copper-doped carbon dots (Cu-CDs) that display enhanced catalytic (catalase-like, peroxidase-like) activity in the oral environment for inhibiting initial bacteria (Streptococcus mutans) adhesion and for subsequent biofilm eradication without impacting the surrounding oral tissues via oxygen (O2) and reactive oxygen species (ROS) generation. Especially, Cu-CDs exhibit strong affinity for lipopolysaccharides (LPS) and peptidoglycans (PGN), thus conferring them with excellent antibacterial ability against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), such that they can prevent wound purulent infection and promoting rapid wound healing. Additionally, the Cu-CDs/H2O2 system shows a better performance in tooth whitening, compared with results obtained with other alternatives, e.g., CDs and clinically used H2O2, particularly its negligible enamel and dentin destruction. It is anticipated that the biocompatible Cu-CDs presented in this work are a promising nano-mouthwash for eliminating oral pathogenic biofilms, prompting wound healing as well as tooth whitening, highlighting their significance in oral health management.


Assuntos
Cobre , Infecção dos Ferimentos , Humanos , Cobre/farmacologia , Carbono , Peróxido de Hidrogênio , Staphylococcus aureus , Biofilmes , Antibacterianos/farmacologia , Escherichia coli , Coloração e Rotulagem
14.
ACS Nano ; 16(6): 9130-9141, 2022 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-35584060

RESUMO

Photodynamic therapy as an emerging phototheranostic approach holds great potential for antibacterial treatment, but is limited by compromised reactive oxygen species (ROS) generation in an aggregate and hypoxic microenvironment. Herein, we report a molecular cationization approach to boost the ROS, especially type I ROS generation of aggregation-induced emission (AIE) photosensitizers for photodynamic treatment of drug-resistant bacteria. Such cationization reinforces the electron-accepting ability of the cationic moiety, promotes intersystem crossing (ISC), and increases electron separation and transfer processes. The resultant CTBZPyI exhibits largely enhanced ROS generation ability with predominant hydroxyl radical generation over its neutral counterpart in aggregate. Moreover, cationization also confers CTBZPyI with the bacterial binding ability and a moderate bacterial inactivation ability in the dark. Further light irradiation leads to superb antibacterial performance, which largely promotes the healing process of a MRSA-infected wound. Such a cationization strategy is expected to be a general strategy for the design of highly effective type I photosensitizers for bacterial infection treatment.


Assuntos
Fotoquimioterapia , Fármacos Fotossensibilizantes , Fármacos Fotossensibilizantes/química , Espécies Reativas de Oxigênio/metabolismo , Antibacterianos/farmacologia , Bactérias/metabolismo
15.
Sensors (Basel) ; 22(7)2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35408210

RESUMO

Circular synthetic aperture radar (CSAR), which can observe the region of interest for a long time and from multiple angles, offers the opportunity for moving-target detection (MTD). However, traditional MTD methods cannot effectively solve the problem of high probability of false alarm (PFA) caused by strong clutter. To mitigate this, a novel, three-step scheme combining clutter background extraction, multichannel clutter suppression, and the degree of linear consistency of radial velocity interferometric phase (DLRVP) test is proposed. In the first step, the spatial similarity of the scatterers and the correlation between sub-aperture images are fused to extract the strong clutter mask prior to clutter suppression. In the second step, using the data remaining after elimination of the background clutter in Step 1, an amplitude-based detector with higher processing gain is utilized to detect potential moving targets. In the third step, a novel test model based on DLRVP is proposed to further reduce the PFA caused by isolated strong scatterers. After the above processing, almost all false alarms are excluded. Measured data verified that the PFA of the proposed method is only 20% that of the comparison method, with improved detection of slow and weakly moving targets and with better robustness.

16.
Small ; 18(17): e2200743, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35347841

RESUMO

Developing effective therapies to fight against biofilm-associated infection is extremely urgent. The complex environment of biofilm forces the bacteria to evade the elimination of antibiotics, resulting in recalcitrant chronic infections. To address this issue, a cationic antibacterial agent based on phosphindole oxide (ß-PM-PIO) is designed and prepared. The unique molecular structure endows ß-PM-PIO with aggregation-induced emission feature and efficient singlet oxygen generation ability. ß-PM-PIO shows excellent visual diagnostic function to planktonic bacteria and biofilm. In addition, owing to the synergistic effect of phototoxicity and dark toxicity, ß-PM-PIO can achieve superb antibacterial and antibiofilm performance against Gram-positive bacteria with less potential of developing drug resistance. Notably, ß-PM-PIO also holds excellent anti-infection capacity against drug-resistant bacteria in vivo with negligible side effects. This work offers a promising platform to develop advanced antibacterial agents against multidrug-resistant bacterial infection.


Assuntos
Infecções Bacterianas , Fármacos Fotossensibilizantes , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias , Biofilmes , Cátions , Humanos , Testes de Sensibilidade Microbiana , Óxidos/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Plâncton
17.
Adv Healthc Mater ; 10(24): e2101067, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34418328

RESUMO

The in situ visualization of drugs can improve the understanding of their pharmacokinetics and mechanisms. Aggregation-induced emission (AIE) materials, which can aid in the visualization of drugs, are gradually being employed in pharmaceutical research due to their excellent fluorescence properties, good biocompatibility, and extremely high sensitivity. Herein, the progress of AIE materials in pharmaceutical research, including AIE carriers for drug delivery, AIE multifunctional prodrugs, and AIE compounds as bioactive reagents for theranostics is briefly described. Moreover, the opportunities and challenges of AIE materials in pharmaceutical research are discussed in depth. It is believed that versatile AIE materials hold great promise for the promotion of pharmacological research and can facilitate significant advancements in clinical fields.


Assuntos
Pesquisa Farmacêutica , Sistemas de Liberação de Medicamentos , Fluorescência , Medicina de Precisão
18.
Opt Express ; 29(11): 15918-15939, 2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34154167

RESUMO

Triangular frequency-modulated continuous-wave (FMCW) laser radars (ladars) are extremely sensitive to vibration errors. An FMCW ladar 3D imaging system may suffer from severe vibrations and can use only one-period echoes for the ranging of each observation spot; consequently, it can provide only few measurement results. These vibrations may cause large errors because conventional vibration compensation methods are ineffective when applied to fast disturbances with limited measurement results. To solve this problem, we analyze the influence of vibrations on FMCW ladar ranging and propose a vibration compensation method based on an instantaneous ranging model for one-period triangular FMCW ladar signals. We first use a synchrosqueezing wavelet transform to extract time-frequency curves of the up- and down-dechirp signals and then build an instantaneous ranging model that can characterize local vibration errors. Based on the instantaneous ranges, we remove the disturbance vibration errors by taking the mean values of the instantaneous ranges and obtain the target range by using the triangular relations of the up and down observations. Experiments based on synthetic and real data verify the effectiveness of the proposed method and its superiority over the three-point method and Doppler shift method in compensating for vibrations with different frequencies and noise levels.

19.
Adv Healthc Mater ; 10(12): e2100136, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34019741

RESUMO

New ionic compounds with aggregation-induced emission (AIE) feature has been widely studied. These AIE-based luminogens (AIEgens) not only effectively resolve aggregation-caused quenching (ACQ) problems that are encountered for most of conventional fluorescent dyes, but also exhibit promising applications in biological imaging, potentially for a wide variety of diseases. However, such an AIE system needs to be further developed. In this work, a series of novel cationic AIEgens that are comprised of tricyclic 2-aminopyridinium derivatives with seven-membered rings are designed and synthesized via a simple, multicomponent reaction. Notably, these AIEgens exhibit the ability to specifically stain gram-positive bacteria. Moreover, a specific AIEgen, BMTAP-7, possesses highly efficient bacteriostatic ability for Staphylococcus aureus (S. aureus) in both liquid medium and solid agar plates, which have a minimum inhibitory concentration (MIC) between 4 and 8 µg mL-1 . Using live-cell imaging and a wash-free process, it is observed that hydrophilic AIEgens are localized to mitochondria, whereas lipophilic AIEgens display specific staining of lysosomes. These AIEgens with bacteriostatic activity hold great promise for distinguishing between bacterial types and inhibiting bacterial infections in situ.


Assuntos
Corantes Fluorescentes , Staphylococcus aureus , Cátions , Bactérias Gram-Positivas
20.
Angew Chem Int Ed Engl ; 60(27): 14892-14896, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-33900670

RESUMO

An electrochemical ODI-[5+2] cascade reaction was developed which enables the rapid assembly of diversely functionalized bicyclo[3.2.1]octadienones from sensitive ethynylphenols. By combining a directed retro-aldol/aldol process, a [2,3]-sigmatropic rearrangement, and an Al(O-iPr)3 -promoted reductive 1,3-transposition, the asymmetric total syntheses of five 8,9-seco-ent-kauranoids-(-)-shikoccin, (-)-O-methylshikoccin, (-)-epoxyshikoccin, (+)-O-methylepoxyshikoccin, and (+)-rabdo-hakusin-have been achieved in a concise and efficient manner.

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