Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 786
Filtrar
1.
Cell ; 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38657602

RESUMEN

Antigen presentation defects in tumors are prevalent mechanisms of adaptive immune evasion and resistance to cancer immunotherapy, whereas how tumors evade innate immunity is less clear. Using CRISPR screens, we discovered that IGSF8 expressed on tumors suppresses NK cell function by interacting with human KIR3DL2 and mouse Klra9 receptors on NK cells. IGSF8 is normally expressed in neuronal tissues and is not required for cell survival in vitro or in vivo. It is overexpressed and associated with low antigen presentation, low immune infiltration, and worse clinical outcomes in many tumors. An antibody that blocks IGSF8-NK receptor interaction enhances NK cell killing of malignant cells in vitro and upregulates antigen presentation, NK cell-mediated cytotoxicity, and T cell signaling in vivo. In syngeneic tumor models, anti-IGSF8 alone, or in combination with anti-PD1, inhibits tumor growth. Our results indicate that IGSF8 is an innate immune checkpoint that could be exploited as a therapeutic target.

2.
Biomol Biomed ; 2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38581716

RESUMEN

The application of immune checkpoint inhibitors has proven to be an effective treatment for cancer. Immune checkpoints such as programmed cell death protein 1/programmed cell death protein 1 ligand 1 (PD-1/PD-L1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), T-cell immunoglobulin-3 (TIM-3), T-cell immunoglobulin and ITIM domain (TIGIT), and lymphocyte activation gene-3 (LAG-3) have received extensive attention, and the efficacy of antibodies or inhibitors against these checkpoints (either alone or in combination) has been evaluated in many tumors. This paper provides a brief overview of the PD-1 and LAG-3 checkpoints, and then shifts focus to the combined use of PD-1 and LAG-3 antibodies in both in vivo and in vitro experiments. In the in vitro experiments, we examined the correlation between the expression and activation of these inhibitors on T cells, and also assessed toxicity in animals in preparation for in vivo experiments. The effects of the combined use of PD-1 and LAG-3 antibodies were then summarized in animal models of melanoma, MC38 carcinoma, and other tumors. In clinical studies, the combined application of these antibodies was assessed in patients with melanoma, colorectal, breast, and renal cell cancers, as well as other solid tumors. In general, the combination of PD-1 and LAG-3 antibodies has shown promising results in both in vivo and in vitro studies.

3.
J Fungi (Basel) ; 10(4)2024 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-38667917

RESUMEN

Fusarium sacchari is a causal agent of sugarcane Pokkah boeng, an important fungal disease that causes a considerable reduction in yield and sugar content in susceptible varieties of sugarcane worldwide. Despite its importance, the fungal factors that regulate the virulence of this pathogen remain largely unknown. In our previous study, mapping of an insertional mutant defect in virulence resulted in the identification of a cutinase G-box binding protein gene, designated FsCGBP, that encodes a C2H2-type transcription factor (TF). FsCGBP was shown to localize in the nuclei, and the transcript level of FsCGBP was significantly upregulated during the infection process or in response to abiotic stresses. Deletion or silencing of FsCGBP resulted in a reduction in mycelial growth, conidial production, and virulence and a delay in conidial germination in the F. sacchari. Cutinase genes FsCUT2, FsCUT3, and FsCUT4 and the mitogen-activated protein kinase (MAPK) genes FsHOG1, FsMGV1, and FsGPMK1, which were significantly downregulated in ΔFsCGBP. Except for FsHOG1, all of these genes were found to be transcriptionally activated by FsCGBP using the yeast one-hybrid system in vitro. The deletion of individual cutinase genes did not result in any of the phenotypes exhibited in the ΔFsCGBP mutant, except for cutinase activity. However, disruption of the MAPK pathway upon deletion of FsMGV1 or FsGPMK1 resulted in phenotypes similar to those of the ΔFsCGBP mutant. The above results suggest that FsCGBP functions by regulating the MAPK pathway and cutinase genes, providing new insights into the mechanism of virulence regulation in F. sacchari.

4.
Anal Methods ; 16(14): 2071-2076, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38505988

RESUMEN

The thermal desorption (TD) technique is widely employed in modern mass spectrometry to facilitate the detection of non-volatile analytes. In this study, we developed a compact TD device based on a small resistance wire and coupled it with a self-aspirating corona discharge ionization (CDI) source to conduct direct MS analysis of various liquid and solid samples. Due to its small size and low heat capacity, the temperature of the TD module can be flexibly and rapidly modulated by controlling the power sequence. Multiple heating modes, including pulse heating (PH), isothermal heating, and step heating (SH), are realized and characterized, and then applied for the detection of different real samples. In particular, the PH mode is suitable for the simultaneous detection of multiple components in samples with relatively simple matrices, while the SH mode is capable of component separation. In addition, the sensitivity and quantitative capability of the TD-CDI system for DEP solutions were tested, showing acceptable stability with a relative standard deviation of about 6.7% and a detection limit of 0.088 ng. Overall, the developed TD-CDI system provides a simple, convenient, and versatile tool for direct mass spectrometry analysis of real samples.

5.
Pest Manag Sci ; 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38488318

RESUMEN

BACKGROUND: Voltage-dependent anion-selective channels (VDACs) serve as pore proteins within the mitochondrial membrane, aiding in the regulation of cell life and cell death. Although the occurrence of cell death is crucial for defense against virus infection, the function played by VDAC in Bombyx mori, in response to the influence of Bombyx mori nucleopolyhedrovirus (BmNPV), remains unclear. RESULTS: BmVDAC was found to be relatively highly expressed both during embryonic development, and in the Malpighian tubule and midgut. Additionally, the expression levels of BmVDAC were found to be different among silkworm strains with varying levels of resistance to BmNPV, strongly suggesting a connection between BmVDAC and virus infection. To gain further insight into the function of BmVDAC in BmNPV, we employed RNA interference (RNAi) to silence and overexpress it by pIZT/V5-His-mCherry. The results revealed that BmVDAC is instrumental in developing the resistance of host cells to BmNPV infection in BmN cell-line cells, which was further validated as likely to be associated with initiating programmed cell death (PCD). Furthermore, we evaluated the function of BmVDAC in another insect, Spodoptera exigua. Knockdown of the BmVDAC homolog in S. exigua, SeVDAC, made the larvae more sensitive to BmNPV. CONCLUSION: We have substantiated the pivotal role of BmVDAC in conferring resistance against BmNPV infection, primarily associated with the initiation of PCD. The findings of this study shine new light on the molecular mechanisms governing the silkworm's response to BmNPV infection, thereby supporting innovative approaches for pest biocontrol. © 2024 Society of Chemical Industry.

6.
Food Chem ; 446: 138811, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38412809

RESUMEN

Mislabeling the geographical origin of coffee is a prevalent form of fraud. In this study, a rapid, nondestructive, and high-throughput method combining mass spectrometry (MS) analysis and intelligence algorithms to classify coffee origin was developed. Specifically, volatile compounds in coffee aroma were detected using self-aspiration corona discharge ionization mass spectrometry (SACDI-MS), and the acquired MS data were processed using a customized deep learning algorithm to perform origin authentication automatically. To facilitate high-throughput analysis, an air curtain sampling device was designed and coupled with SACDI-MS to prevent volatile mixing and signal overlap. An accuracy of 99.78% was achieved in the classification of coffee samples from six origins at a throughput of 1 s per sample. The proposed approach may be effective in preventing coffee fraud owing to its straightforward operation, rapidity, and high accuracy and thus benefit consumers.


Asunto(s)
Aprendizaje Profundo , Compuestos Orgánicos Volátiles , Café/química , Odorantes/análisis , Espectrometría de Masas/métodos , Algoritmos , Compuestos Orgánicos Volátiles/análisis
7.
Insect Mol Biol ; 33(3): 246-258, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38323672

RESUMEN

Molybdenum cofactor sulfurase (MoCoS) is a key gene involved in the uric acid metabolic pathway that activates xanthine dehydrogenase to synthesise uric acid. Uric acid is harmful to mammals but plays crucial roles in insects, one of which is the immune responses. However, the function of Bombyx mori MoCoS in response to BmNPV remains unclear. In this study, BmMoCoS was found to be relatively highly expressed in embryonic development, gonads and the Malpighian tubules. In addition, the expression levels of BmMoCoS were significantly upregulated in three silkworm strains with different levels of resistance after virus infection, suggesting a close link between them. Furthermore, RNAi and overexpression studies showed that BmMoCoS was involved in resistance to BmNPV infection, and its antivirus effects were found to be related to the regulation of uric acid metabolism, which was uncovered by inosine- and febuxostat-coupled RNAi and overexpression. Finally, the BmMoCoS-mediated uric acid pathway was preliminarily confirmed to be a potential target to protect silkworms from BmNPV infection. Overall, this study provides new evidence for elucidating the molecular mechanism of silkworms in response to BmNPV infection and new strategies for the prevention of viral infections in sericulture.


Asunto(s)
Bombyx , Nucleopoliedrovirus , Ácido Úrico , Animales , Bombyx/virología , Bombyx/genética , Bombyx/metabolismo , Bombyx/crecimiento & desarrollo , Ácido Úrico/metabolismo , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Larva/metabolismo , Larva/crecimiento & desarrollo , Larva/virología , Metaloproteínas/metabolismo , Metaloproteínas/genética , Cofactores de Molibdeno , Interferencia de ARN
8.
J Prim Care Community Health ; 15: 21501319231224253, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38212904

RESUMEN

INTRODUCTION: Self-efficacy in individuals optimizes their hypertension management. Electronic patient portals are being increasingly used to support chronic disease management, as they raise the health literacy of patients and enable them in self-management. However, the association between the use of patient portals and self-efficacy in hypertension management remains unclear. The study aimed to determine the association between self-efficacy among patients with hypertension who are managed in primary care and their demographic characteristics and usage patterns of patient portals. METHOD: A cross-sectional survey was conducted at a public primary care clinic in urban Singapore. Multi-ethnic adult patients with hypertension were invited to participate in a self-administered electronic questionnaire. Chi-square test was performed for bivariate analysis; adjusted logistic regression models were used for factors with P value <.1. RESULTS: A total of 310 patients (66.8% Chinese, 55.5% males, mean age of 63.1 years) completed the survey. Patient portal users had higher self-efficacy scores than non-users (mean score=63 vs 60, maximum = 80, P = .011). The factors associated with increased patient portal access included younger age <65 years (absolute odds ratio [AOR] = 2.634, 95%CI = 1.432-4.847; P = .002), monthly income >$5000 (AOR = 2.324, 95%CI = 1.104-4.892; P = .026), and post-secondary education level (AOR = 3.128, 95%CI = 1.675-5.839; P < .001). Most patients (93.1%) used the portal to check medical appointments but only1.3% of them used it to record home blood pressure measurements (HBPM). CONCLUSIONS: Patient portal usage was associated with higher self-efficacy scores in patients with hypertension. These users were younger, more educated, and earned more than the non-users, but only 1.3% of them used it for HBPM documentation.


Asunto(s)
Alfabetización en Salud , Hipertensión , Portales del Paciente , Adulto , Masculino , Humanos , Persona de Mediana Edad , Anciano , Femenino , Autoeficacia , Estudios Transversales , Hipertensión/terapia
9.
Clin Oral Investig ; 28(1): 121, 2024 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-38280038

RESUMEN

OBJECTIVE: We aimed to develop a tool for virtual orthodontic bracket removal based on deep learning algorithms for feature extraction from bonded teeth and to demonstrate its application in a bracket position assessment scenario. MATERIALS AND METHODS: Our segmentation network for virtual bracket removal was trained using dataset A, containing 978 bonded teeth, 20 original teeth, and 20 brackets generated by scanners. The accuracy and segmentation time of the network were tested by dataset B, which included an additional 118 bonded teeth without knowing the original tooth morphology. This tool was then applied for bracket position assessment. The clinical crown center, bracket center, and orientations of separated teeth and brackets were extracted for analyzing the linear distribution and angular deviation of bonded brackets. RESULTS: This tool performed virtual bracket removal in 2.9 ms per tooth with accuracies of 98.93% and 97.42% (P < 0.01) in datasets A and B, respectively. The tooth surface and bracket characteristics were extracted and used to evaluate the results of manually bonded brackets by 49 orthodontists. Personal preferences for bracket angulation and bracket distribution were displayed graphically and tabularly. CONCLUSIONS: The tool's efficiency and precision are satisfactory, and it can be operated without original tooth data. It can be used to display the bonding deviation in the bracket position assessment scenario. CLINICAL SIGNIFICANCE: With the aid of this tool, unnecessary bracket removal can be avoided when evaluating bracket positions and modifying treatment plans. It has the potential to produce retainers and orthodontic devices prior to tooth debonding.


Asunto(s)
Aprendizaje Profundo , Recubrimiento Dental Adhesivo , Soportes Ortodóncicos , Recubrimiento Dental Adhesivo/métodos , Desconsolidación Dental/métodos , Microscopía Electrónica de Rastreo
10.
Int J Biol Macromol ; 254(Pt 3): 128024, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37972830

RESUMEN

The cocoon silk of silkworms (Bombyx mori) has multiple potential applications in biomedicine due to its good biocompatibility, mechanical properties, degradability, and plasticity. Numerous studies have confirmed that silk material dressings are more effective than traditional ones in the skin wound healing process. Silk material research has recently moved toward functionalized biomaterials and achieved remarkable results. Herein, we summarize the recent advances in functionalized silk materials and their efficacy in skin wound healing. In particular, transgenic technology has realized the specific expression of human growth factors in the silk glands of the silkworms, which lays the foundation for fabricating novel and low-cost functionalized materials. Without a green and safe preparation process, the best raw silk materials cannot be made into medically safe products. Therefore, we provide an overview of green and gentle approaches for silk degumming and silk sericin (SS) extraction. Moreover, we summarize and discuss the processing methods of silk fibroin (SF) and SS materials and their potential applications, such as burns, diabetic wounds, and other wounds. This review aims to enhance our understanding of new advances and directions in silk materials and guide future biomedical research.


Asunto(s)
Bombyx , Fibroínas , Animales , Humanos , Seda , Materiales Biocompatibles/farmacología , Cicatrización de Heridas , Fibroínas/farmacología
11.
Sci China Life Sci ; 67(3): 475-487, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37219765

RESUMEN

Cardiopulmonary bypass has been speculated to elicit systemic inflammation to initiate acute lung injury (ALI), including acute respiratory distress syndrome (ARDS), in patients after cardiac surgery. We previously found that post-operative patients showed an increase in endothelial cell-derived extracellular vesicles (eEVs) with components of coagulation and acute inflammatory responses. However, the mechanism underlying the onset of ALI owing to the release of eEVs after cardiopulmonary bypass, remains unclear. Plasma plasminogen-activated inhibitor-1 (PAI-1) and eEV levels were measured in patients with cardiopulmonary bypass. Endothelial cells and mice (C57BL/6, Toll-like receptor 4 knockout (TLR4-/-) and inducible nitric oxide synthase knockout (iNOS-/-)) were challenged with eEVs isolated from PAI-1-stimulated endothelial cells. Plasma PAI-1 and eEVs were remarkably enhanced after cardiopulmonary bypass. Plasma PAI-1 elevation was positively correlated with the increase in eEVs. The increase in plasma PAI-1 and eEV levels was associated with post-operative ARDS. The eEVs derived from PAI-1-stimulated endothelial cells could recognize TLR4 to stimulate a downstream signaling cascade identified as the Janus kinase 2/3 (JAK2/3)-signal transducer and activator of transcription 3 (STAT3)-interferon regulatory factor 1 (IRF-1) pathway, along with iNOS induction, and cytokine/chemokine production in vascular endothelial cells and C57BL/6 mice, ultimately contributing to ALI. ALI could be attenuated by JAK2/3 or STAT3 inhibitors (AG490 or S3I-201, respectively), and was relieved in TLR4-/- and iNOS-/- mice. eEVs activate the TLR4/JAK3/STAT3/IRF-1 signaling pathway to induce ALI/ARDS by delivering follistatin-like protein 1 (FSTL1), and FSTL1 knockdown in eEVs alleviates eEV-induced ALI/ARDS. Our data thus demonstrate that cardiopulmonary bypass may increase plasma PAI-1 levels to induce FSTL1-enriched eEVs, which target the TLR4-mediated JAK2/3/STAT3/IRF-1 signaling cascade and form a positive feedback loop, leading to ALI/ARDS after cardiac surgery. Our findings provide new insight into the molecular mechanisms and therapeutic targets for ALI/ARDS after cardiac surgery.


Asunto(s)
Lesión Pulmonar Aguda , Vesículas Extracelulares , Proteínas Relacionadas con la Folistatina , Síndrome de Dificultad Respiratoria , Animales , Humanos , Ratones , Lesión Pulmonar Aguda/etiología , Lesión Pulmonar Aguda/tratamiento farmacológico , Lesión Pulmonar Aguda/metabolismo , Células Endoteliales/metabolismo , Vesículas Extracelulares/metabolismo , Proteínas Relacionadas con la Folistatina/metabolismo , Proteínas Relacionadas con la Folistatina/uso terapéutico , Inflamación/metabolismo , Lipopolisacáridos/farmacología , Pulmón/metabolismo , Ratones Endogámicos C57BL , Inhibidor 1 de Activador Plasminogénico/metabolismo , Inhibidor 1 de Activador Plasminogénico/uso terapéutico , Síndrome de Dificultad Respiratoria/etiología , Receptor Toll-Like 4/metabolismo , Receptor Toll-Like 4/uso terapéutico
12.
Sci Adv ; 9(48): eadg9721, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-38039357

RESUMEN

The efficacy of CAR-T cells for solid tumors is unsatisfactory. EpCAM is a biomarker of epithelial tumors, but the clinical feasibility of CAR-T therapy targeting EpCAM is lacking. Here, we report pre- and clinical investigations of EpCAM-CAR-T cells for solid tumors. We demonstrated that EpCAM-CAR-T cells costimulated by Dectin-1 exhibited robust antitumor activity without adverse effects in xenograft mouse models and EpCAM-humanized mice. Notably, in clinical trials for epithelial tumors (NCT02915445), 6 (50%) of the 12 enrolled patients experienced self-remitted grade 1/2 toxicities, 1 patient (8.3%) experienced reversible grade 3 leukopenia, and no higher-grade toxicity reported. Efficacy analysis determined two patients as partial response. Three patients showed >23 months of progression-free survival, among whom one patient experienced 2-year progress-free survival with detectable CAR-T cells 200 days after infusion. These data demonstrate the feasibility and tolerability of EpCAM-CAR-T therapy.


Asunto(s)
Neoplasias Glandulares y Epiteliales , Receptores Quiméricos de Antígenos , Humanos , Animales , Ratones , Molécula de Adhesión Celular Epitelial , Linfocitos T , Inmunoterapia/efectos adversos , Neoplasias Glandulares y Epiteliales/tratamiento farmacológico
13.
Anal Chem ; 95(47): 17407-17415, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-37963290

RESUMEN

The mass spectrometer is an important tool for modern chemical analysis and detection. Especially, the emergence of miniature mass spectrometers has provided new tools for field analysis and detection. The resolution of a mass spectrometer reflects the ability of the instrument to discriminate between adjacent mass-to-charge ratio ions, and the higher the resolution, the better the discrimination of complex mixtures. Quadrupole ion traps are generally considered as a low-resolution mass spectrometry method, but they have gained wide attention and development in recent years because of their suitability for miniaturization and high qualitative capability. For an ion trap mass spectrometer, the mass sensitivity and resolution can be mutually constrained and need to be balanced by setting an appropriate scanning speed. In this study, a super-resolution U-net algorithm (SR-Unet) is proposed for ion trap mass spectrometry, which can estimate the possible ions from the overlapping ion peaks of low-resolution spectra and improve the equivalent resolution while ensuring sufficient sensitivity and analysis speed of the instrument. By determining the mass spectra of a linear ion trap mass spectrometer (LTQ XL) in Turbo and Normal scan modes, the same unit mass resolution as that at a scan speed of 16,667 Da/s was successfully obtained at 125,000 Da/s. Also, the experiments demonstrated that the algorithm is capable of the mass-to-charge ratio and instrument migration. SR-Unet can be migrated and applied to a miniature mass spectrometer for cruise detection of volatile organic compounds (VOCs), and the identification of VOC species in Photochemical Assessment Monitoring Stations (PAMS) was improved from 31 to 50 species with the same monitoring and analysis speed requirement. Further, super-unit mass resolution peptide detection was achieved on a miniature mass spectrometer with the help of the SR-Unet algorithm, which reduced the full width at half-maxima (FWHM) of bradykinin divalent ions (m/z 531) from 0.35 to 0.15 Da at a scan speed of 375 Da/s and improved the equivalent resolution to 3540. The proposed method provides a new idea to enhance the field mixture detection capability of miniature ion trap mass spectrometers.

14.
Anal Chem ; 95(47): 17166-17169, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-37966263

RESUMEN

As a simple soft ionization method, photoionization (PI) is often coupled with mass spectrometry (MS) for the direct analysis of volatile organic compounds (VOCs). PI enables selective ionization of analytes, but the ion yield is generally not high due to the limited light intensity of the ultraviolet lamp. Here, a hydrogen-assisted photoionization (HAPI) strategy was developed and integrated into a miniature ion trap mass spectrometer. In particular, hydrogen was introduced as a versatile buffer gas to facilitate both photoionization and ion trap operation. This can increase the ion yields by up to 2 orders of magnitude compared to conventional PI-MS, with a low hydrogen consumption (less than 100 µL) for each analysis. The generation of protonated ions indicates a specific photochemical process in HAPI, which has also been studied and initially revealed. The detection of various VOCs and plant volatile gases confirmed the versatility and practicality of the HAPI technology.

15.
Hum Gene Ther ; 34(23-24): 1248-1256, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37917093

RESUMEN

Distant metastasis and primary tumor relapse are the two main hurdles to the success of surgical treatment for cancer patients. Circulating tumor cells (CTCs) and incomplete surgical resection are the primary cause of distant metastasis and local recurrence of tumors, respectively. Chimeric antigen receptor (CAR)-modified T cells target residual carcinomas and CTCs hold the potential to inhibit primary recurrence and reduce tumor metastasis, but the experimental evidence is lacking. Here, we developed a surgery-induced tumor metastasis model in immunocompetent mice to investigate the efficacy of CAR-T cells therapy in preventing metastasis and local recurrence. We observed that subcutaneous tumor resection has induced a large number of CTCs intravasated into circulation. EpCAM-specific CAR-T was effective in clearing CTCs following surgical removal of the tumor. This resulted in less pulmonary metastasis and longer survival in mice when compared to mice treated with surgery followed by Mock-T cells infusion. In addition, the local relapse was obviously inhibited at the surgical site followed by EpCAM-CAR-T cell treatment. This study demonstrated that CAR-T cell therapy can be an adjuvant treatment following surgery to prevent tumor metastasis and inhibit primary tumor relapse for cancer patients.


Asunto(s)
Receptores Quiméricos de Antígenos , Humanos , Animales , Ratones , Receptores Quiméricos de Antígenos/genética , Molécula de Adhesión Celular Epitelial/genética , Recurrencia Local de Neoplasia/prevención & control , Recurrencia Local de Neoplasia/patología , Inmunoterapia Adoptiva/métodos , Recurrencia , Tratamiento Basado en Trasplante de Células y Tejidos
16.
Entropy (Basel) ; 25(10)2023 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-37895498

RESUMEN

The Minimum Vertex Weighted Coloring (MinVWC) problem is an important generalization of the classic Minimum Vertex Coloring (MinVC) problem which is NP-hard. Given a simple undirected graph G=(V,E), the MinVC problem is to find a coloring s.t. any pair of adjacent vertices are assigned different colors and the number of colors used is minimized. The MinVWC problem associates each vertex with a positive weight and defines the weight of a color to be the weight of its heaviest vertices, then the goal is the find a coloring that minimizes the sum of weights over all colors. Among various approaches, reduction is an effective one. It tries to obtain a subgraph whose optimal solutions can conveniently be extended into optimal ones for the whole graph, without costly branching. In this paper, we propose a reduction algorithm based on maximal clique enumeration. More specifically our algorithm utilizes a certain proportion of maximal cliques and obtains lower bounds in order to perform reductions. It alternates between clique sampling and graph reductions and consists of three successive procedures: promising clique reductions, better bound reductions and post reductions. Experimental results show that our algorithm returns considerably smaller subgraphs for numerous large benchmark graphs, compared to the most recent method named RedLS. Also, we evaluate individual impacts and some practical properties of our algorithm. Furthermore, we have a theorem which indicates that the reduction effects of our algorithm are equivalent to that of a counterpart which enumerates all maximal cliques in the whole graph if the run time is sufficiently long.

17.
Sci Bull (Beijing) ; 68(23): 2982-2992, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37798176

RESUMEN

Electrocatalytic oxidation of renewable biomass (such as glucose) into high-value-added chemicals provides an effective approach to achieving carbon neutrality. CuO-derived materials are among the most promising electrocatalysts for biomass electrooxidation, but the identification of their active sites under electrochemical conditions remains elusive. Herein, we report a potential-dependent structure evolution over CuO in the glucose oxidation reaction (GOR). Through systematic electrochemical and spectroscopic characterizations, we unveil that CuO undergoes Cu2+/Cu+ and Cu3+/Cu2+ redox processes at increased potentials with successive generation of Cu(OH)2 and CuOOH as the active phases. In addition, these two structures have distinct activities in the GOR, with Cu(OH)2 being favorable for aldehyde oxidation, and CuOOH showed faster kinetics in carbon-carbon cleavage and alcohol/aldehyde oxidation. This work deepens our understanding of the dynamic reconstruction of Cu-based catalysts under electrochemical conditions and may guide rational material design for biomass valorization.

19.
Adv Clin Chem ; 115: 1-32, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37673518

RESUMEN

New psychoactive substances (NPS) are chemical compounds designed to mimic the action of existing illicit recreational drugs. Synthetic cannabinoids (SCs) are a subclass of NPS which bind to the cannabinoid receptors, CB1 and CB2, and mimic the action of cannabis. SCs have dominated recent NPS seizure reports worldwide. While urine is the most common matrix for drug-of-abuse testing, SCs undergo extensive Phase I and Phase II metabolism, resulting in almost undetectable parent compounds in urine samples. Therefore, the major urinary metabolites of SCs are usually investigated as surrogate biomarkers to identify their consumption. Since seized urine samples after consuming novel SCs may be unavailable in a timely manner, human hepatocytes, human liver microsomes and human transporter overexpressed cell lines are physiologically-relevant in vitro systems for performing metabolite identification, metabolic stability, reaction phenotyping and transporter experiments to establish the disposition of SC and its metabolites. Coupling these in vitro experiments with in vivo verification using limited authentic urine samples, such a two-pronged approach has proven to be effective in establishing urinary metabolites as biomarkers for rapidly emerging SCs.


Asunto(s)
Líquidos Corporales , Cannabinoides , Drogas Ilícitas , Humanos , Biomarcadores
20.
Exp Dermatol ; 32(11): 1900-1914, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37622736

RESUMEN

Psoriasis is an autoimmune skin disease that often co-occurs with psychological morbidities such as anxiety and depression, and psychosocial issues also lead psoriasis patients to avoid other people. However, the precise mechanism underlying the comorbidity of psoriasis and anxiety is unknown. Also, whether the social avoidance phenomenon seen in human patients also exists in psoriasis-like animal models remains unknown. In the present study, anxiety-like behaviours and social avoidance-like behaviours were observed in an imiquimod-induced psoriasis-like C57-BL6 mouse model along with typical psoriasis-like dermatitis and itch-like behaviours. The 11.7T resting-state functional magnetic resonance imaging showed differences in brain regions between the model and control group, and voxel-based morphometry showed that the grey matter volume changed in the basal forebrain region, anterior commissure intrabulbar and striatum in the psoriasis-like mice. Seed-based resting state functional connectivity analysis revealed connectivity changes in the amygdala, periaqueductal gray, raphe nuclei and lateral septum. We conclude that the imiquimod-induced psoriasis-like C57-BL6 mouse model is well suited for mechanistic studies and for performing preclinical therapeutic trials for treating anxiety and pathological social avoidance in psoriasis patients.


Asunto(s)
Imagen por Resonancia Magnética , Psoriasis , Humanos , Ratones , Animales , Imiquimod , Ansiedad/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Psoriasis/diagnóstico por imagen , Psoriasis/psicología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...