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OBJECTIVE: Colorectal cancer (CRC), specifically colon adenocarcinoma, is the third most prevalent and the second most lethal form of cancer. Anoikis is found to be specialized form of programmed cell death (PCD), which plays a pivotal role in tumor progression. This study aimed to investigate the role of the anoikis related genes (ARGs) in colon cancer. METHODS: Consensus unsupervised clustering, differential expression analysis, tumor mutational burden analysis, and analysis of immune cell infiltration were utilized in the study. For the analysis of RNA sequences and clinical data of COAD patients, data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were obtained. A prognostic scoring system for overall survival (OS) prediction was developed using Cox regression and LASSO regression analysis. Furthermore, loss-of-function assay was utilized to explore the role of RAD9A played in the progression of colon cancer. RESULTS: The prognostic value of a risk score composed of NTRK2, EPHA2, RAD9A, CDC25C, and SNAI1 genes was significant. Furthermore, these findings suggested potential mechanisms that may influence prognosis, supporting the development of individualized treatment plans and management of patient outcomes. Further experiments confirmed that RAD9A could promote proliferation and metastasis of colon cancer cells. These effects may be achieved by affecting the phosphorylation of AKT. CONCLUSION: Differences in survival time and the tumor immune microenvironment (TIME) were observed between two gene clusters associated with ARGs. In addition, a prognostic risk model was established and confirmed as an independent risk factor. Furthermore, our data indicated that RAD9A promoted tumorigenicityby activating AKT in colon cancer.
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Nanodomain engineering in lithium niobate on insulator (LNOI) is critical to realize advanced photonic circuits. Here, we investigate the tip-induced nanodomain formation in x-cut LNOI. The effective electric field exhibits a mirror symmetry, which can be divided into preceding and sequential halves according to the tip movement. Under our configuration, the preceding electric field plays a decisive role rather than the sequential one as in previous reports. The mechanism is attributed to the screening field formed by the preceding field counteracting the effect of the subsequent one. In experiment, we successfully fabricate nanodomain dots, lines, and periodic arrays. Our work offers a useful approach for nanoscale domain engineering in x-cut LNOI, which has potential applications in integrated optoelectronic devices.
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Myrosinase (Myr) catalyzes the hydrolysis of glucosinolates, yielding biologically active metabolites. In this study, glucoraphanin (GRA) extracted from broccoli seeds was effectively hydrolyzed using a Myr-obtained cabbage aphid (Brevicoryne brassicae) (BbMyr) to produce (R)-sulforaphane (SFN). The gene encoding BbMyr was successfully heterologously expressed in Escherichia coli, resulting in the production of 1.6 g/L (R)-SFN, with a remarkable yield of 20.8 mg/gbroccoli seeds, achieved using recombination E. coli whole-cell catalysis under optimal conditions (pH 4.5, 45 °C). Subsequently, BbMyr underwent combinatorial simulation-driven mutagenesis, yielding a mutant, DE9 (N321D/Y426S), showing a remarkable 2.91-fold increase in the catalytic efficiency (kcat/KM) compared with the original enzyme. Molecular dynamics simulations demonstrated that the N321D mutation in loopA of mutant DE9 enhanced loopA stability by inducing favorable alterations in hydrogen bonds, while the Y426S mutation in loopB decreased spatial resistance. This research lays a foundation for the environmentally sustainable enzymatic (R)-SFN synthesis.
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Afídeos , Brassica , Glicosídeo Hidrolases , Isotiocianatos , Sulfóxidos , Sulfóxidos/química , Sulfóxidos/metabolismo , Animais , Isotiocianatos/metabolismo , Isotiocianatos/química , Afídeos/enzimologia , Afídeos/genética , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Glicosídeo Hidrolases/química , Brassica/genética , Brassica/enzimologia , Brassica/química , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Proteínas de Insetos/química , Glucosinolatos/metabolismo , Glucosinolatos/química , Cinética , Simulação de Dinâmica Molecular , Oximas/química , Oximas/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Evolução Molecular Direcionada , Imidoésteres/metabolismo , Imidoésteres/químicaRESUMO
Objective: To compare the clinical efficacy of endoscopic retrograde cholangiopancreatography (ERCP) combined with laparoscopic cholecystectomy (LC) and laparoscopic common bile duct exploration and lithotomy (LCBDE) in the treatment of cholecystolithiasis combined with bile duct stones. Methods: From September 2018 to January 2022, 195 patients with cholecystolithiasis complicated with extrahepatic bile duct stones from Department of Department of General Surgery, Shanghai Jiading Central Hospital met the inclusion criteria, including 60 cases in the LC group and 86 cases in the LCBDE group. The general condition, operation success rate, complications and residual stone rate of the two groups were retrospectively analyzed. Results: In the simultaneous operation group, 58 patients successfully performed ERCP, and the indwelling rate of the abdominal drainage tube (41.7 % vs. 95.3 %) was significantly better than that in the LCBDE group. There was no significant difference in the conversion rate to open surgery, operation time, and intraoperative blood loss between the two groups. In the simultaneous surgery group, 4 patients (6.7 %) developed pancreatitis after ERCP, which was cured by conservative treatment. The pain score at 6 h after operation was significantly lower than that in the LCBDE group (3.9 ± 1.6 vs 6.5 ± 2.4). There were no significant differences in biliary leakage (1.7 % vs. 4.7 %), postoperative cholangitis (5.0 % vs. 5.8 %), incision infection (3.3 % vs. 3.5 %), and bile duct stone residue rate (5.0 % vs 3.5 %) between the two groups. There was no severe pancreatitis, second operation or death. The duration of hospital stay was shortened in the concurrent operation group (5.1 ± 2.3d vs 7.9 ± 3.7d), and the operation cost was significantly higher than that in the LCBDE group (48839.9 ± 8549.5 vs 34635.9 ± 5893.7 yuan). Conclusion: ERCP combined with LC and LCBDE are both safe and effective methods for the treatment of cholecystolithiasis combined with extrahepatic bile duct stones. The simultaneous operation group has certain advantages in patient comfort and rapid rehabilitation, which can be popularized in qualified units.
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Metal nanoparticle (NP) cocatalysts are widely investigated for their ability to enhance the performance of photocatalytic materials; however, their practical application is often limited by the inherent instability under light irradiation. This challenge has catalyzed interest in exploring high-entropy alloys (HEAs), which, with their increased entropy and lower Gibbs free energy, provide superior stability. In this study, 3.5 nm-sized noble-metal-free NPs composed of a FeCoNiCuMn HEA are successfully synthesized. With theoretic calculation and experiments, the electronic structure of HEA in augmenting the catalytic CO2 reduction has been uncovered, including the individual roles of each element and the collective synergistic effects. Then, their photocatalytic CO2 reduction capabilities are investigated when immobilized on TiO2. HEA NPs significantly enhance the CO2 photoreduction, achieving a 23-fold increase over pristine TiO2, with CO and CH4 production rates of 235.2 and 19.9 µmol g-1 h-1, respectively. Meanwhile, HEA NPs show excellent stability under simulated solar irradiation, as well high-energy X-ray irradiation. This research emphasizes the promising role of HEA NPs, composed of earth-abundant elements, in revolutionizing the field of photocatalysis.
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BACKGROUND: Bladder cancer (BC), a prevalent malignancy in the urinary system, often poses challenges for effective treatment. Immunotherapy, harnessing the immune system, has exhibited promise in early-stage clinical trials. Mucosal associated invariant T (MAIT) cells, a subset of immune cells implicated in various diseases, including certain cancer, have yet to be explored in BC patients. We aimed to investigate the quantity, function, and anti-tumor effects of MAIT cells in BC patients. METHODS: A total of 75 newly diagnosed BC patients and 183 healthy volunteers were included. Blood samples were collected and analyzed to evaluate the quantity and function of MAIT cells. Surgical resection provided BC tissues for further analysis, and the clinical features of BC tumors were collected and their relationship with MAIT cells was explored. RESULTS: MAIT cells were identified in both healthy individuals and BC patients. The proportion of MAIT cells in the peripheral blood of BC patients did not significantly differ from that of healthy controls. However, the study revealed a correlation between the proportion of IFN-γ producing MAIT cells and tumor number and invasion in BC patients. Furthermore, MAIT cells exhibited cytotoxic effects on BC cells in vitro and in vivo. CONCLUSIONS: This study sheds light on the role of MAIT cells in BC. While the quantity of MAIT cells showed no significant change in BC patients, their functional attributes and association with tumor characteristics suggest their potential as an immunotherapy target in BC treatment.
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Células T Invariantes Associadas à Mucosa , Neoplasias da Bexiga Urinária , Humanos , Neoplasias da Bexiga Urinária/imunologia , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/terapia , Células T Invariantes Associadas à Mucosa/imunologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Animais , Interferon gama/metabolismo , Adulto , Linhagem Celular Tumoral , Imunoterapia/métodos , Camundongos , Citotoxicidade ImunológicaRESUMO
Polyphenolic compounds have natural antioxidant properties, and their antioxidant activity is usually related to the number and position of hydroxyls. Here, we successfully applied the engineered 4-hydroxyphenylacetate 3-hydroxylases (4HPA3Hs) derived from Pseudomonas aeruginosa to catalyze ferulic acid (FA) synthesis of ortho-hydroxyferulic acid (5-hydroxyferulic acid, 5-OHFA). Through optimization of co-expression, the oxygenase component (PaHpaB) and the reductase component (PaHpaC) in E. coli, and optimization of whole-cell catalytic conditions, the engineered strain BC catalyzed ortho-hydroxylation of 2 g/L of FA with a yield of 75 % from 39 %. Through tunnel engineering of PaHpaB, the obtained mutants F301A and Q376A almost completely transformed 2 g/L of FA. Further, a multiple mutant L214A/F301A/Q376A converted 4 g/L FA into 5-OHFA within 12 h, and the yield reached 99.9 %, which was approximately 2.39-fold of the wild type. The kcat/Km value of L214A/F301A/Q376A was about 307 times greater than that of the wide type. Analysis of three-dimensional structural models showed that L214, F301, and Q376 mutated into Ala, which greatly shortened the side chain and broadened the tunnel size, thereby significantly improving the catalytic efficiency of L214A/F301A/Q376A. This biosynthesis of 5-OHFA is simple, efficient, and green, suggesting that it is useful for efficient biosynthesis of polyphenolic compounds.
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Ácidos Cumáricos , Oxigenases de Função Mista , Fenilacetatos , Pseudomonas aeruginosa , Oxigenases de Função Mista/química , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Hidroxilação , Escherichia coli/metabolismoRESUMO
OBJECTIVES: The dissemination of New Delhi metallo-ß-lactamase-5 (NDM-5) among various species of Enterobacterales has attracted serious global attention. Here, we characterise the genomic characterisation of blaNDM-5-IncX3 plasmid (pNDM-KA3) in an ST4 Klebsiella aerogenes (KA3) strain isolated from a neonate with pneumonia. METHODS: Antimicrobial susceptibility and multilocus sequence typing was performed for the KA3. The plasmid conjugation assay and plasmid stability of the KA3 (pNDM-KA3) were also analysed. The pNDM-KA3 plasmid was further analysed by whole-genome sequencing and comparative analysis to determine the genetic environment of blaNDM-5. RESULTS: The KA3 strain belongs to ST4 and shows high resistance to ß-lactam antibiotics, including carbapenems, but is susceptible to ciprofloxacin, amikacin, tigecycline, and colistin. The pNDM-KA3 was successfully transferred to the recipient E. coli J53 and showed strong stability in K. aerogenes. Genomic sequencing revealed that the pNDM-KA3 plasmid was assigned to plasmid incompatibility group X3 with 43367 bp, and a conserved structure sequence of â³IS3000-â³ISAba125-IS5-blaNDM-5-bleMBL- trpF-dsbC-IS26 was detected upstream and downstream of the blaNDM-5 gene. Further analysis revealed that insertion sequences mediated the dissemination of blaNDM-5 from other species of Enterobacterales. The pNDM-KA3 showed high similarity to blaNDM-5-harbouring plasmids in other species of Enterobacterales, with these plasmids carrying genes for replication (repB), partitioning (parA and parB), stability (hns), and conjugative transfer (virB and virD). CONCLUSIONS: Continued monitoring for the dissemination of blaNDM-5 among uncommon Enterobacterales species should be further reinforced.
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Antibacterianos , Enterobacter aerogenes , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Plasmídeos , Sequenciamento Completo do Genoma , beta-Lactamases , Plasmídeos/genética , beta-Lactamases/genética , Humanos , Antibacterianos/farmacologia , Enterobacter aerogenes/genética , Enterobacter aerogenes/efeitos dos fármacos , Enterobacter aerogenes/isolamento & purificação , Recém-Nascido , Genoma Bacteriano , Infecções por Klebsiella/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Conjugação GenéticaRESUMO
Phenylalanine ammonia-lyase (PAL) plays a pivotal role in the biosynthesis of phenylalanine. PAL from Zea mays (ZmPAL2) exhibits a bi-function of direct deamination of L-phenylalanine (L-Phe) or L-tyrosine(-L-Tyr) to form trans-cinnamic acid or p-coumaric acid. trans-Cinnamic acid and p-coumaric acid are mainly used in flavors and fragrances, food additives, pharmaceutical and other fields. Here, the Activity of ZmPAL2 toward L-Phe or L-Tyr was improved by using semi-rational and rational designs. The catalytic efficiency (kcat/Km) of mutant PT10 (V258I/I459V/Q484N) against L-Phe was 30.8⯵M-1 s-1, a 4.5-fold increase compared to the parent, and the catalytic efficiency of mutant PA1 (F135H/I459L) to L-tyrosine exhibited 8.6⯵M-1 s-1, which was 1.6-fold of the parent. The yield of trans-cinnamic acid in PT10 reached 30.75â¯g/L with a conversion rate of 98%. Meanwhile, PA1 converted L-Tyr to yield 3.12â¯g/L of p-coumaric acid with a conversion rate of 95%. Suggesting these two engineered ZmPAL2 to be valuable biocatalysts for the synthesis of trans-cinnamic acid and p-coumaric acid. In addition, MD simulations revealed that the underlying mechanisms of the increased catalytic efficiency of both mutant PT10 and PA1 are attributed to the substrate remaining stable within the pocket and closer to the catalytically active site. This also provides a new perspective on engineered PAL.
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Cinamatos , Ácidos Cumáricos , Fenilalanina Amônia-Liase , Zea mays , Fenilalanina Amônia-Liase/genética , Fenilalanina Amônia-Liase/química , Fenilalanina , TirosinaRESUMO
Understanding the mixing behaviour of elements in a multielement material is important to control its structure and property. When the size of a multielement material is decreased to the nanoscale, the miscibility of elements in the nanomaterial often changes from its bulk counterpart. However, there is a lack of comprehensive and quantitative experimental insight into this process. Here we explored how the miscibility of Au and Rh evolves in nanoparticles of sizes varying from 4 to 1 nm and composition changing from 15% Au to 85% Au. We found that the two immiscible elements exhibit a phase-separation-to-alloy transition in nanoparticles with decreased size and become completely miscible in sub-2 nm particles across the entire compositional range. Quantitative electron microscopy analysis and theoretical calculations were used to show that the observed immiscibility-to-miscibility transition is dictated by particle size, composition and possible surface adsorbates present under the synthesis conditions.
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OBJECTIVE: To explore the combined effect of abdominal obesity and depressive symptoms on the risk to type 2 diabetes, while also assessing the potential influence of various glycemic states and gender on this combined relationship. METHODS: Data is acquired from the China Health and Retirement Longitudinal Study, and 5949 participants were included for analysis. Participants were divided into four groups: neither have abdominal obesity nor depressive symptoms (AO-/DS-), only have depressive symptoms (AO-/DS+), only have abdominal obesity (AO+/DS-), and have both abdominal obesity and depressive symptoms (AO+/DS+). Stratified analyses differentiating the glycemic statuses and sex of the participants were also carried out. RESULTS: After adjusting for the confounders, the AO-/DS+, AO+/DS- and AO+/DS+ phenotypes were all discovered to be risk factors for type 2 diabetes (OR = 1.38, 95%CI: 1.06-1.79; OR = 2.07, 95%CI: 1.63-2.63; OR = 2.38, 95%CI: 1.83-3.11, respectively) compared with the AO-/DS- phenotype in the overall population. In further stratified analyses, we arrived at the same conclusion for normoglycemic individuals, especially in females. For prediabetes and males, the AO+/DS- and AO+/DS+ phenotypes are risk factors for type 2 diabetes compared with the AO-/DS- phenotype, but not with AO-/DS+. CONCLUSION: Regardless of glycemic status and sex, the coexistence of abdominal obesity and depressive symptoms were associated with an increased risk of type 2 diabetes. Depressive symptoms were independent risk factors for type 2 diabetes only in normoglycemic individuals and females.
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Diabetes Mellitus Tipo 2 , Masculino , Feminino , Humanos , Estudos de Coortes , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/complicações , Obesidade Abdominal/complicações , Obesidade Abdominal/epidemiologia , Estudos Longitudinais , Depressão/complicações , Obesidade/complicações , Fatores de RiscoRESUMO
Macropinocytosis, an evolutionarily conserved endocytic pathway, mediates nonselective bulk uptake of extracellular fluid. It is the primary route for axenic Dictyostelium cells to obtain nutrients and has also emerged as a nutrient-scavenging pathway for mammalian cells. How cells adjust macropinocytic activity in various physiological or developmental contexts remains to be elucidated. We discovered that, in Dictyostelium cells, the transcription factors Hbx5 and MybG form a functional complex in the nucleus to maintain macropinocytic activity during the growth stage. In contrast, during starvation-induced multicellular development, the transcription factor complex undergoes nucleocytoplasmic shuttling in response to oscillatory cyclic adenosine 3',5'-monophosphate (cAMP) signals, which leads to increased cytoplasmic retention of the complex and progressive downregulation of macropinocytosis. Therefore, by coupling macropinocytosis-related gene expression to the cAMP oscillation system, which facilitates long-range cell-cell communication, the dynamic translocation of the Hbx5-MybG complex orchestrates a population-level adjustment of macropinocytic activity to adapt to changing environmental conditions.
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Dictyostelium , Animais , Dictyostelium/metabolismo , Pinocitose/fisiologia , Citoplasma , Núcleo Celular , Fatores de Transcrição/metabolismo , MamíferosRESUMO
Photothermal therapy (PTT), which utilizes nanomaterials to harvest laser energy and convert it into heat to ablate tumor cells, has been rapidly developed for lung tumor treatment, but most of the PTT-related nanomaterials are not degradable, and the immune response associated with PTT is unclear, which leads to unsatisfactory results of the actual PTT. Herein, we rationally designed and prepared a manganese ion-doped polydopamine nanomaterial (MnPDA) for immune-activated PTT with high efficiency. Firstly, MnPDA exhibited 57.2% photothermal conversion efficiency to accomplish high-efficiency PTT, and secondly, MnPDA can be stimulated by glutathione (GSH) to the release of Mn2+, and it can produce ·OH in a Fenton-like reaction with the overexpressed H2O2 and stimulate the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. These two synergistically can effectively remove lung tumor cells that have not been ablated by PTT, resulting in an 86.7% tumor suppression rate under laser irradiation of MnPDA in vivo, and further significantly activated the downstream immune response, as evidenced by an increased ratio of cytotoxic T cells to immunosuppressive Treg cells. Conclusively, the GSH degradable MnPDA nanoparticles can be used for photothermal therapy and cGAS-STING-activated immunotherapy of lung tumors, which provides a new idea and strategy for the future treatment of lung tumors.
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Indóis , Neoplasias Pulmonares , Nanopartículas , Neoplasias , Polímeros , Humanos , Manganês , Peróxido de Hidrogênio , Terapia Fototérmica , Imunoterapia , Neoplasias Pulmonares/terapia , GlutationaRESUMO
Computational design advances enzyme evolution and their use in biocatalysis in a faster and more efficient manner. In this study, a synergistic approach integrating tunnel engineering, evolutionary analysis, and force-field calculations has been employed to enhance the catalytic activity of D-lactonohydrolase (D-Lac), which is a pivotal enzyme involved in the resolution of racemic pantolactone during the production of vitamin B5. The best mutant, N96S/A271E/F274Y/F308G (M3), was obtained and its catalytic efficiency (kcat/KM) was nearly 23-fold higher than that of the wild-type. The M3 whole-cell converted 20 % of DL-pantolactone into D-pantoic acid (D-PA, >99 %â e.e.) with a conversion rate of 47 % and space-time yield of 107.1â g L-1 h-1, demonstrating its great potential for industrial-scale D-pantothenic acid production. Molecular dynamics (MD) simulations revealed that the reduction in the steric hindrance within the substrate tunnel and conformational reconstruction of the distal loop resulted in a more favourable"catalytic" conformation, making it easier for the substrate and enzyme to enter their pre-reaction state. This study illustrates the potential of the distal residue on the pivotal loop at the entrance of the D-Lac substrate tunnel as a novel modification hotspot capable of reshaping energy patterns and consequently influencing the enzymatic activity.
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4-Butirolactona/análogos & derivados , Simulação de Dinâmica Molecular , Engenharia de Proteínas , Engenharia de Proteínas/métodos , CatáliseRESUMO
Objective: Cholangiocarcinoma (CHOL) is a malignant disease that affects the digestive tract, and it is characterized by a poor prognosis. This research sought to explore the involvement of cuproptosis-related lncRNAs (CRLs) in the prognostic prediction and immune infiltration of cholangiocarcinoma. Methods: The expression profiles and clinical data of CHOL patients were acquired from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, and CRLs were defined via co-expression analysis. Two molecular clusters distinguished by cuproptosis-related genes (CRGs) were produced. Then a risk signature consisted by four CRLs was formed, and all samples were separated into low- and high-risk groups using a risk score. Kaplan-Meier survival analysis, principal component analysis, differentially expressed analysis, immune cell infiltration analysis, and sensitivities analysis of chemotherapy drugs were conducted between the two groups. Simultaneously, the expression values of four lncRNAs confirmed by real-time PCR in our own 20 CHOL samples were brought into the risk model. Results: The CHOL samples could be differentiated into two molecular clusters, which displayed contrasting survival times. Additionally, patients with higher risk scores had significantly worse prognosis compared to those in the low-risk group. Furthermore, both immune infiltration and enrichment analysis revealed significant discrepancies in the tumor immune microenvironment (TIME) between different risk groups. Moreover, the predictive power and the correlation with CA19-9 and CEA of risk signature were validated in our own samples. Conclusion: We developed a risk signature which could serve as an independent prognostic factor and offer a promising prediction for not only prognosis but also TIME in CHOL patients.
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A nonlinear holographic technique is capable of processing optical information in the newly generated optical frequencies, enabling fascinating functions in laser display, security storage, and image recognition. One popular nonlinear hologram is based on a periodically poled lithium niobate (LN) crystal. However, due to the limitations of traditional fabrication techniques, the pixel size of the LN hologram is typically several micrometers, resulting in a limited field-of-voew (FOV) of several degrees. Here, we experimentally demonstrate an ultra-high-resolution LN hologram by using the laser poling technique. The minimal pixel size reaches 200 nm, and the FOV is extended above 120° in our experiments. The image distortions at large view angles are effectively suppressed through the Fourier transform. The FOV is further improved by combining multiple diffraction orders of SH fields. The ultimate FOV under our configuration is decided by a Fresnel transmission. Our results pave the way for expanding the applications of nonlinear holography to wide-view imaging and display.
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4-Hydroxyphenylacetate 3-hydroxylase (4HPA3H) is a long-known class of two-component flavin-dependent monooxygenases from bacteria, including an oxygenase component (EC 1.14.14.9) and a reductase component (EC 1.5.1.36), with the latter being accountable for delivering the cofactor (reduced flavin) essential for o-hydroxylation. 4HPA3H has a broad substrate spectrum involved in key biological processes, including cellular catabolism, detoxification, and the biosynthesis of bioactive molecules. Additionally, it specifically hydroxylates the o-position of the C4 position of the benzene ring in phenolic compounds, generating high-value polyhydroxyphenols. As a non-P450 o-hydroxylase, 4HPA3H offers a viable alternative for the de novo synthesis of valuable natural products. The enzyme holds the potential to replace plant-derived P450s in the o-hydroxylation of plant polyphenols, addressing the current significant challenge in engineering specific microbial strains with P450s. This review summarizes the source distribution, structural properties, and mechanism of 4HPA3Hs and their application in the biosynthesis of natural products in recent years. The potential industrial applications and prospects of 4HPA3H biocatalysts are also presented.
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Produtos Biológicos , Oxigenases de Função Mista , Fenilacetatos , Oxigenases de Função Mista/metabolismo , Hidroxilação , Flavinas/químicaRESUMO
Strain gradients widely exist in development and physiological activities. The directional movement of cells is essential for proper cell localization, and directional cell migration in responses to gradients of chemicals, rigidity, density, and topography of extracellular matrices have been well-established. However; it is unclear whether strain gradients imposed on cells are sufficient to drive directional cell migration. In this work, a programmable uniaxial cell stretch device is developed that creates controllable strain gradients without changing substrate stiffness or ligand distributions. It is demonstrated that over 60% of the single rat embryonic fibroblasts migrate toward the lower strain side in static and the 0.1 Hz cyclic stretch conditions at ≈4% per mm strain gradients. It is confirmed that such responses are distinct from durotaxis or haptotaxis. Focal adhesion analysis confirms higher rates of contact area and protrusion formation on the lower strain side of the cell. A 2D extended motor-clutch model is developed to demonstrate that the strain-introduced traction force determines integrin fibronectin pairs' catch-release dynamics, which drives such directional migration. Together, these results establish strain gradient as a novel cue to regulate directional cell migration and may provide new insights in development and tissue repairs.