Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.695
Filtrar
1.
Brief Bioinform ; 2023 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-36892171

RESUMO

The adaptive immune receptor repertoire (AIRR), consisting of T- and B-cell receptors, is the core component of the immune system. The AIRR sequencing is commonly used in cancer immunotherapy and minimal residual disease (MRD) detection of leukemia and lymphoma. The AIRR is captured by primers and sequenced to yield paired-end (PE) reads. The PE reads could be merged into one sequence by the overlapped region between them. However, the wide range of AIRR data raises the difficulty, so a special tool is required. We developed a software package for IMmune PE reads merger of sequencing data, named IMperm. We used the k-mer-and-vote strategy to pin down the overlapped region rapidly. IMperm could handle all types of PE reads, eliminate adapter contamination and successfully merge low-quality and minor/non-overlapping reads. Compared with existing tools, IMperm performed better in both simulated and sequencing data. Notably, IMperm was well suited to processing the data of MRD detection in leukemia and lymphoma and detected 19 novel MRD clones in 14 patients with leukemia from previously published data. Additionally, IMperm can handle PE reads from other sources, and we demonstrated its effectiveness on two genomic and one cell-free deoxyribonucleic acid datasets. IMperm is implemented in the C programming language and consumes little runtime and memory. It is freely available at https://github.com/zhangwei2015/IMperm.

2.
Curr Microbiol ; 80(5): 142, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36930356

RESUMO

An actinobacterium, designated as SYSU T00001T, was isolated from a tidal flat sediment sample from Guangdong province, China. Cells were Gram-stain-positive, aerobic, motile and short rod-shaped. Colonies on marine agar 2216 were smooth, yellow-pigmented, and circular with low convexity. The isolate was able to grow at the temperature range 4-37 °C (optimum 30 °C), at pH 4.0-10.0 (optimum 7.0) and in the presence of 0-10% (w/v) NaCl. The major menaquinones were MK-11 and MK-10. The cell wall contained alanine, glutamic acid, lysine and ornithine. The major fatty acids were C19:0 cyclo ω8c (35.7%) and anteiso C15:0 (26.0%). The polar lipids consisted of one diphosphatidyl glycerol, one unidentified glycolipid and one unknown lipid. Whole genome sequencing of strain SYSU T00001T revealed 2,837,702 bp with a DNA G + C content of 67.8%. Phylogenetic analyses clearly demonstrated that strain SYSU T00001T belonged to the genus Salinibacterium, and the highest 16S rRNA gene similarity to Salinibacterium hongtaonis 194T (97.8%). The ANI and dDDH values of strain SYSU T00001T relative to Salinibacterium hongtaonis 194T were 74.5% and 19.5%, respectively. According to our data, strain SYSU T00001T represents a novel species of the genus Salinibacterium, for which the name Salinibacterium sedimenticola sp. nov. is proposed, the type strain is SYSU T00001T (= GDMCC 1.3283T = KCTC 49758T).

3.
J Econ Entomol ; 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36895199

RESUMO

Increased atmospheric CO2 concentrations may directly affect insect behavior. Thrips hawaiiensis Morgan and T. flavus Schrank are economically important thrips pests native to China. We studied the development, survival, and oviposition of these two thrips under elevated CO2 concentrations (800 µl liter-1) and ambient CO2 (400 µl liter-1; control) conditions. Both thrips species developed faster but had lower survival rates under elevated CO2 levels compared with control conditions (developmental time: 13.25 days vs. 12.53 days in T. hawaiiensis, 12.18 days vs. 11.61 days in T. flavus; adult survival rate: 70.00% vs. 64.00% in T. hawaiiensis, 65.00% vs. 57.00% in T. flavus under control vs. 800 µl liter-1 CO2 conditions, respectively). The fecundity, net reproductive rate (R0), and intrinsic rate of increase (rm) of the two species were also lower under elevated CO2 concentrations (fecundity: 47.96 vs. 35.44 in T. hawaiiensis, 36.68 vs. 27.88 in T. flavus; R0: 19.83 vs. 13.62 in T. hawaiiensis, 14.02 vs. 9.86 in T. flavus; and rm: 0.131 vs. 0.121 in T. hawaiiensis, 0.113 vs. 0.104 in T. flavus under control and 800 µl liter-1 CO2 conditions, respectively). T. hawaiiensis developed slower but had a higher survival rate, fecundity, R0, and rm compared with T. flavus at each CO2 concentration. In summary, elevated CO2 concentrations negatively affected T. hawaiiensis and T. flavus populations. In a world with higher CO2 concentrations, T. hawaiiensis might be competitively superior to T. flavus where they co-occur.

4.
Sci Total Environ ; 876: 162584, 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36889407

RESUMO

Modeling stomatal behavior is necessary for accurate stomatal simulation and predicting the terrestrial water­carbon cycle. Although the Ball-Berry and Medlyn stomatal conductance (gs) models have been widely used, variations and the drivers of their key slope parameters (m and g1) remain poorly understood under salinity stress. We measured leaf gas exchange, physiological and biochemical traits, soil water content and electrical conductivity of saturation extract (ECe), and fitted slope parameters of two genotypes of maize growing in two water and two salinity levels. We found m was different between the genotypes, but no difference in g1. Salinity stress reduced m and g1, saturated stomatal conductance (gsat), the fraction of leaf epidermis area allocation to stomata (fs), and leaf nitrogen (N) content, and increased ECe, but no marked decrease in slope parameters under drought. Both m and g1 were positively correlated with gsat, fs, and leaf N content, and negatively correlated with ECe in the same fashion among the two genotypes. Salinity stress altered m and g1 by modulating gsat and fs via leaf N content. The prediction accuracy of gs was improved using salinity-specific slope parameters, with root mean square error (RMSE) being decreased from 0.056 to 0.046 and 0.066 to 0.025 mol m-2 s-1 for the Ball-Berry and Medlyn models, respectively. This study provides a modeling approach to improving the simulation of stomatal conductance under salinity.

5.
Sci Adv ; 9(11): eadf4051, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36921055

RESUMO

Artificial dry adhesives have exhibited great potential in the field of robotics. However, there is still a wide gap between bioinspired adhesives and living tissues, especially regarding the surface adaptability and switching ability of attachment/detachment. Here, we propose a sensing-triggered stiffness-tunable smart adhesive material, combining the functions of muscle tissues and sensing nerves rather than traditional biomimetic adhesive strategy that only focuses on structural geometry. Authorized by real-time perception of the interface contact state, conformal contact, shape locking, and active releasing are achieved by adjusting the stiffness based on the magnetorheological effect. Because of the fast switching of the magnetic field, a millisecond-level attachment/detachment response is successfully achieved, breaking the bottleneck of adhesive materials for high-speed manipulation. The innovative design can be applied to any toe's surface structure, opening up a previously unknown avenue for the development of adhesive materials.

6.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 45(1): 117-123, 2023 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-36861164

RESUMO

Intervention mapping (IM) is a framework for formulating theory-and evidence-based health education projects with participatory approaches from ecological perspectives.The intervention program designed via IM plays a role in reducing the exposure of cancer risk factors,increasing cancer prevention behaviors,and promoting early cancer screening and rehabilitation of cancer patients.This study summarizes the characteristics,implementation steps,and application status of IM in tertiary prevention of cancer,aiming to provide reference for the application of IM in the health education projects for cancer in China.


Assuntos
Neoplasias , Humanos , Prevenção Terciária , Neoplasias/prevenção & controle , China , Fatores de Risco
7.
Sci Adv ; 9(11): eadd5582, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36930720

RESUMO

Using genome-wide data of 89 ancient individuals dated to 5100 to 100 years before the present (B.P.) from 29 sites across the Tibetan Plateau, we found plateau-specific ancestry across plateau populations, with substantial genetic structure indicating high differentiation before 2500 B.P. Northeastern plateau populations rapidly showed admixture associated with millet farmers by 4700 B.P. in the Gonghe Basin. High genetic similarity on the southern and southwestern plateau showed population expansion along the Yarlung Tsangpo River since 3400 years ago. Central and southeastern plateau populations revealed extensive genetic admixture within the plateau historically, with substantial ancestry related to that found in southern and southwestern plateau populations. Over the past ~700 years, substantial gene flow from lowland East Asia further shaped the genetic landscape of present-day plateau populations. The high-altitude adaptive EPAS1 allele was found in plateau populations as early as in a 5100-year-old individual and showed a sharp increase over the past 2800 years.

8.
J Genet Genomics ; 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36933795

RESUMO

The settlement of the Tibetan Plateau epitomizes human adaptation to a high-altitude environment that poses great challenges to human activity. Here, we reconstructed a 4000-year maternal genetic history of Tibetans using 128 ancient mitochondrial genome data from 37 sites in Tibet. The phylogeny of haplotypes M9a1a, M9a1b, D4g2, G2a'c, and D4i show ancient Tibetans shared the most recent common ancestor (TMRCA) with ancient Middle and Upper Yellow River populations around the Early and Middle Holocene. In addition, the connections between Tibetans and Northeastern Asians varied over the past 4000 years, with a stronger matrilineal connection between the two during 4000-3000 BP, and a weakened connection after 3000 BP, that coincident with climate change, followed by a reinforced connection after the Tubo period (1400-1100 BP). Besides, an over 4000-year matrilineal continuity was observed in some of the maternal lineages. We also found the maternal genetic structure of ancient Tibetans is correlated to the geography and interactions between ancient Tibetans and ancient Nepal and Pakistan populations. Overall, the maternal genetic history of Tibetans can be characterized as a long-term matrilineal continuity with frequent internal and external population interactions that were dynamically shaped by geography, climate changes, as well as historical events.

9.
Brief Bioinform ; 2023 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-36907658

RESUMO

The adaptive immune response to foreign antigens is initiated by T-cell receptor (TCR) recognition on the antigens. Recent experimental advances have enabled the generation of a large amount of TCR data and their cognate antigenic targets, allowing machine learning models to predict the binding specificity of TCRs. In this work, we present TEINet, a deep learning framework that utilizes transfer learning to address this prediction problem. TEINet employs two separately pretrained encoders to transform TCR and epitope sequences into numerical vectors, which are subsequently fed into a fully connected neural network to predict their binding specificities. A major challenge for binding specificity prediction is the lack of a unified approach to sampling negative data. Here, we first assess the current negative sampling approaches comprehensively and suggest that the Unified Epitope is the most suitable one. Subsequently, we compare TEINet with three baseline methods and observe that TEINet achieves an average AUROC of 0.760, which outperforms baseline methods by 6.4-26%. Furthermore, we investigate the impacts of the pretraining step and notice that excessive pretraining may lower its transferability to the final prediction task. Our results and analysis show that TEINet can make an accurate prediction using only the TCR sequence (CDR3$\beta $) and the epitope sequence, providing novel insights to understand the interactions between TCRs and epitopes.

10.
Surg Endosc ; 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36917343

RESUMO

OBJECTIVE: The objective of the study was to assess the validity of the NASA-TLX score in rating the workload of pediatric robotic operations. METHODS: The workload of 230 pediatric gastrointestinal and thoracic robotic operations was rated using the NASA-TLX score. The difference between the high workload group and the low workload group in each subscale of the NASA-TLX score was analyzed. The correlation of each subscale with the total workload score in the high workload group and low workload group was also analyzed. A logistic regression analysis was subsequently conducted to assess the effects of different factors (sex, age, weight, procedure duration, procedure specialties, combined malformation and blood loss) on the workload. RESULTS: The average NASA-TLX score was 56.5 ± 5.1 for the total group, 56.9 ± 5.0 for the gastrointestinal group and 54.6 ± 4.8 for the thoracic group, p = 0.007. The score of the high workload group was 62.7 ± 3.2, while it was 50.6 ± 2.7 for the low workload group (p < 0.001). The score on each subscale was also significantly different between the high and low workload groups. In the high workload group, a stronger correlation was observed between the total score and TD and Fr and a lower correlation with MD and Pe. In the low workload group, all six subscales showed a moderate correlation with the total score. A multivariate logistic regression analysis revealed that the procedure duration was an independent influencing factor for a higher workload score. CONCLUSIONS: NASA-TLX is a valid tool to rate the surgeon's workload in pediatric robotic surgery. A longer operative time contributes to a higher workload.

11.
Int J Mol Sci ; 24(5)2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36902033

RESUMO

Despite the significant progress that has been made in terms of understanding the pathophysiology and risk factors of Hirschsprung-associated enterocolitis (HAEC), the morbidity rate has remained unsatisfactorily stable, and clinical management of the condition continues to be challenging. Therefore, in the present literature review, we summarized the up-to-date advances that have been made regarding basic research on the pathogenesis of HAEC. Original articles published between August 2013 and October 2022 were searched in a number of databases, including PubMed, Web of Science, and Scopus. The keywords "Hirschsprung enterocolitis", "Hirschsprung's enterocolitis", "Hirschsprung's-associated enterocolitis", and "Hirschsprung-associated enterocolitis" were selected and reviewed. A total of 50 eligible articles were obtained. The latest findings of these research articles were grouped into gene, microbiome, barrier function, enteric nervous system, and immune state categories. The present review concludes that HAEC is shown to be a multifactorial clinical syndrome. Only deep insights into this syndrome, with an accrual of knowledge in terms of understanding its pathogenesis, will elicit the necessary changes that are required for managing this disease.


Assuntos
Sistema Nervoso Entérico , Enterocolite , Doença de Hirschsprung , Microbiota , Humanos , Lactente , Doença de Hirschsprung/genética , Enterocolite/etiologia , Sistema Nervoso Entérico/patologia , Fatores de Risco
12.
Int J Mol Sci ; 24(5)2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36902211

RESUMO

The small brown planthopper (SBPH, Laodelphax striatellus) is one of the most destructive insect pests in rice (Oryza sativa), which is the world's major grain crop. The dynamic changes in the rice transcriptome and metabolome in response to planthopper female adult feeding and oviposition have been reported. However, the effects of nymph feeding remain unclear. In this study, we found that pre-infestation with SBPH nymphs increased the susceptibility of rice plants to SBPH infestation. We used a combination of broadly targeted metabolomic and transcriptomic studies to investigate the rice metabolites altered by SBPH feeding. We observed that SBPH feeding induced significant changes in 92 metabolites, including 56 defense-related secondary metabolites (34 flavonoids, 17 alkaloids, and 5 phenolic acids). Notably, there were more downregulated metabolites than upregulated metabolites. Additionally, nymph feeding significantly increased the accumulation of seven phenolamines and three phenolic acids but decreased the levels of most flavonoids. In SBPH-infested groups, 29 differentially accumulated flavonoids were downregulated, and this effect was more pronounced with infestation time. The findings of this study indicate that SBPH nymph feeding suppresses flavonoid biosynthesis in rice, resulting in increased susceptibility to SBPH infestation.


Assuntos
Hemípteros , Oryza , Animais , Feminino , Oryza/genética , Ninfa , Metabolismo Secundário , Perfilação da Expressão Gênica , Hemípteros/genética
13.
Bioinformatics ; 39(3)2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36857587

RESUMO

MOTIVATION: The confusion of acute inflammation infected by virus and bacteria or noninfectious inflammation will lead to missing the best therapy occasion resulting in poor prognoses. The diagnostic model based on host gene expression has been widely used to diagnose acute infections, but the clinical usage was hindered by the capability across different samples and cohorts due to the small sample size for signature training and discovery. RESULTS: Here, we construct a large-scale dataset integrating multiple host transcriptomic data and analyze it using a sophisticated strategy which removes batch effect and extracts the common information from different cohorts based on the relative expression alteration of gene pairs. We assemble 2680 samples across 16 cohorts and separately build gene pair signature (GPS) for bacterial, viral, and noninfected patients. The three GPSs are further assembled into an antibiotic decision model (bacterial-viral-noninfected GPS, bvnGPS) using multiclass neural networks, which is able to determine whether a patient is bacterial infected, viral infected, or noninfected. bvnGPS can distinguish bacterial infection with area under the receiver operating characteristic curve (AUC) of 0.953 (95% confidence interval, 0.948-0.958) and viral infection with AUC of 0.956 (0.951-0.961) in the test set (N = 760). In the validation set (N = 147), bvnGPS also shows strong performance by attaining an AUC of 0.988 (0.978-0.998) on bacterial-versus-other and an AUC of 0.994 (0.984-1.000) on viral-versus-other. bvnGPS has the potential to be used in clinical practice and the proposed procedure provides insight into data integration, feature selection and multiclass classification for host transcriptomics data. AVAILABILITY AND IMPLEMENTATION: The codes implementing bvnGPS are available at https://github.com/Ritchiegit/bvnGPS. The construction of iPAGE algorithm and the training of neural network was conducted on Python 3.7 with Scikit-learn 0.24.1 and PyTorch 1.7. The visualization of the results was implemented on R 4.2, Python 3.7, and Matplotlib 3.3.4.


Assuntos
Transcriptoma , Viroses , Humanos , Redes Neurais de Computação , Bactérias , Viroses/diagnóstico , Viroses/genética , Inflamação
14.
ACS Appl Bio Mater ; 6(2): 848-856, 2023 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-36723405

RESUMO

Since the concept of tissue engineering was proposed, biocompatible hydrogel materials have attracted the attention of researchers. With the help of three-dimensional (3D) printing technology, precise shaping of hydrogels can be realized. In this paper, we synthesized a cellulosic photosensitive acrylamide (AM)/N,N-methylenebisacrylamide (MBA) hydrogel. With the high-efficiency water-soluble photoinitiator TPO@Tw developed by our research group, the efficient photocuring cross-linking process of the hydrogel can be realized under 405 nm visible light. In consideration of the viscosity, curing mass, curing depth, and break distance of the hydrogel, we screened out hydroxypropyl cellulose (HPC) as the preferred tackifier of the material. The addition of HPC greatly improved the mechanical properties of the hydrogel. The compressive modulus of the optimal sample AM-HPC-5 increased by 709.2% and the tensile strength increased by 76.7% compared with the blank control group. By adding a PEGDA shell to the surface of the material, the water retention capacity of the hydrogel was effectively improved. The water loss rate was greatly reduced. The 3D wooden-pile structure model was printed by a DIW 3D printer. Further, through coaxial extrusion, the microtubule structure that may be applied in tissue engineering was obtained. Cell experiment results showed high biocompatibility of the hydrogel. NIH 3T3 cells could adhere and grow on the surface of microtubules.


Assuntos
Hidrogéis , Engenharia Tecidual , Animais , Camundongos , Engenharia Tecidual/métodos , Hidrogéis/química , Materiais Biocompatíveis/química , Luz , Água
15.
Molecules ; 28(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36838691

RESUMO

Brain-type glycogen phosphorylase (PYGB) inhibitors are recognized as prospective drugs for treating ischemic brain injury. We previously reported compound 1 as a novel glycogen phosphorylase inhibitor with brain-protective properties. In this study, we validated whether PYGB could be used as the therapeutic target for hypoxic-ischemic diseases and investigated whether compound 1 exerts a protective effect against astrocyte hypoxia/reoxygenation (H/R) injury by targeting PYGB. A gene-silencing strategy was initially applied to downregulate PYGB proteins in mouse astrocytes, which was followed by a series of cellular experiments with compound 1. Next, we compared relevant indicators that could prove the protective effect of compound 1 on brain injury, finding that after PYGB knockdown, compound 1 could not obviously alleviate astrocytes H/R injury, as evidenced by cell viability, which was not significantly improved, and lactate dehydrogenase (LDH) leakage rate, intracellular glucose content, and post-ischemic reactive oxygen species (ROS) level, which were not remarkably reduced. At the same time, cellular energy metabolism did not improve, and the degree of extracellular acidification was not downregulated after administration of compound 1 after PYGB knockdown. In addition, it could neither significantly increase the level of mitochondrial aerobic energy metabolism nor inhibit the expression of apoptosis-associated proteins. The above results indicate that compound 1 could target PYGB to exert its protective effect against cellular H/R injury in mouse astrocytes. Simultaneously, we further demonstrated that PYGB could be an efficient therapeutic target for ischemic-hypoxic diseases. This study provides a new reference for further in-depth study of the action mechanism of the efficacy of compound 1.


Assuntos
Lesões Encefálicas , Glucose , Camundongos , Animais , Glucose/metabolismo , Glicogênio Fosforilase/metabolismo , Hipóxia/metabolismo , Encéfalo/metabolismo , Lesões Encefálicas/metabolismo , Indóis/farmacologia , Astrócitos
16.
Front Nutr ; 10: 988632, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36776611

RESUMO

Background: Few studies have evaluated the significance of sarcopenia in predicting the outcomes of patients with adenocarcinoma of the esophagogastric junction (AEG), especially those who received neoadjuvant chemoradiotherapy (NCRT). We aimed to identify the sarcopenic status and its impact on the outcomes of patients with locally advanced AEG who received NCRT followed by radical surgery or systemic therapy. Materials and methods: Patients with T3-4N+M0 AEG with accessible abdominal computed tomography (CT) before and after NCRT were retrospectively analyzed. Body composition parameters, particularly the skeletal muscle index (SMI), were assessed using a CT-based method, and sarcopenia was defined using a predetermined SMI cutoff value. Survival analysis was conducted using the Kaplan-Meier method. A Cox proportional hazards regression model was used to identify independent prognostic factors. Receiver operating characteristic curve analysis was carried out, and the area under the curve (AUC) was calculated to test the prognostic accuracy of different factors. Results: A total of 63 patients were enrolled, 65.1 and 79.4% of whom developed pre- and post-NCRT sarcopenia, respectively. Patients with pre-NCRT sarcopenia had lower radical surgery rates (70.7 vs. 95.5%, p = 0.047) than those without sarcopenia; however, sarcopenic status did not affect other short-term outcomes, including treatment-related toxicity and efficacy. Pre-NCRT sarcopenia was identified as an independent predictive factor for poor overall survival (OS) [adjusted hazard ratio (HR), 6.053; p = 0.002] and progression-free survival (PFS) (adjusted HR, 2.873; p = 0.031). Compared with nutritional indices such as the Nutritional Risk Screening 2002, weight loss during NCRT, and post-NCRT sarcopenia, pre-NCRT sarcopenia was regarded as the best predictive index for the 5-year OS (AUC = 0.735) and PFS rates (AUC = 0.770). Conclusion: Pre-NCRT sarcopenia may be an independent predictive factor for OS and PFS rates in patients with locally advanced AEG receiving multimodal treatment.

17.
Opt Express ; 31(2): 2029-2038, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36785225

RESUMO

Manipulating the polarization state of terahertz waves is critical for terahertz communication systems. This study proposes a terahertz band polarization conversion metasurface based on dislocation-induced anisotropy. Numerical simulation results revealed that the polarization conversion of orthogonal linearly polarized light, orthogonal circularly polarized light, linearly polarized light to circularly polarized light, and circularly polarized light to linearly polarized light can be realized. Furthermore, the simulation revealed that multifunctional polarization conversion could be achieved by various structures of the bilayer metasurface. Thus, the proposed design can be generalized. The proposed metasurface exhibits considerable potential for applications in terahertz communications.

18.
J Am Chem Soc ; 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36780205

RESUMO

Spirooxindoles have emerged as promising architectures for engineering biologically active compounds. The diastereodivergent construction of unique scaffolds of this type with full control of continuous chiral centers including an all-carbon quaternary stereogenic center is yet to be developed. Here, we report an unprecedented diastereodivergent desymmetric [3 + 3] annulation of oxabicyclic alkenes with enals enabled by N-heterocyclic carbene (NHC)/Rh cooperative catalysis, leading to a series of enantiomerically enriched spirooxindole lactones with excellent enantioselectivities (up to >99% ee) and diastereoselectivities (up to >95:5 dr). The combined catalyst system comprises a rhodium complex that controls the configuration at the electrophilic carbon and an NHC catalyst that controls the configuration at the nucleophilic oxindole-containing carbon; thus, four stereoisomers of the spirooxindole products can be readily obtained simply by switching the configurations of the two chiral catalysts. Transformations of the chiral spirooxindoles delivered synthetically useful compounds. Importantly, those chiral spirooxindoles arrested mammalian cells in mitosis and exhibited potent antiproliferative activities against HeLa cells. Significantly, both absolute and relative configurations exert prominent effects on the bioactivities, underscoring great importance of catalytic asymmetric diastereodivergent synthesis beyond creating useful tools for the exploration of structure-activity relationships.

19.
Brief Bioinform ; 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36752378

RESUMO

T-cell receptors (TCRs) play an essential role in the adaptive immune system. Probabilistic models for TCR repertoires can help decipher the underlying complex sequence patterns and provide novel insights into understanding the adaptive immune system. In this work, we develop TCRpeg, a deep autoregressive generative model to unravel the sequence patterns of TCR repertoires. TCRpeg largely outperforms state-of-the-art methods in estimating the probability distribution of a TCR repertoire, boosting the average accuracy from 0.672 to 0.906 measured by the Pearson correlation coefficient. Furthermore, with promising performance in probability inference, TCRpeg improves on a range of TCR-related tasks: profiling TCR repertoire probabilistically, classifying antigen-specific TCRs, validating previously discovered TCR motifs, generating novel TCRs and augmenting TCR data. Our results and analysis highlight the flexibility and capacity of TCRpeg to extract TCR sequence information, providing a novel approach for deciphering complex immunogenomic repertoires.

20.
Artigo em Inglês | MEDLINE | ID: mdl-36753048

RESUMO

Environmental humidity and thermal control are of primary importance for fighting global warming, growing energy consumption, and greenhouse gas emissions. Sorption-based atmospheric water harvesting is an emerging technology with great potential in clean water production and passive cooling applications. However, sorption-based humidity management and their hybrid applications are limited due to the lack of energywise designs of hygroscopic materials and devices. Herein, all polymeric 3D foams are developed and evaluated as hygroscopic and photothermal materials. The gas-foaming method generates closed-cell structures with interconnected hydrophilic networks and wrinkled surfaces, expanding hygroscopic, photothermal, and evaporating areas of the 3D foams. These unique advantages lead to efficient water vapor sorption in a wide broad relative humidity (RH) range of 50-90% and efficient water release in a wide solar intensity (0.4-1 sun) and temperature range (27-80 °C). The reversible moisture sorption/release in 50 adsorption/desorption cycles highlights the excellent durability of the 3D foams compared to conventional inorganic desiccants. The 3D foams disclose passive and efficient apparent temperature regulation in warm and humid environments. Moreover, the use of the 3D foams as loose fill for fruit preservation and packaging is demonstrated for the first time by taking the merit of the 3D foams' moisture-absorbing, quick-drying, cushioning, and thermal-insulating properties. This work presents an integrated design of polymeric desiccants and scaffolds, not merely delivering stable water adsorption/desorption but also discovering innovative hybrid applications in humidity management and protective packaging.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...