Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 260
Filtrar
1.
Small ; : e2310360, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38698606

RESUMO

Circulating tumor cells (CTCs) are widely considered as a reliable and promising class of markers in the field of liquid biopsy. As CTCs undergo epithelial-mesenchymal transition (EMT), phenotype detection of heterogeneous CTCs based on EMT markers is of great significance. In this report, an integrated analytical strategy that can simultaneously capture and differentially detect epithelial- and mesenchymal-expressed CTCs in bloods of non-small cell lung cancer (NSCLS) patients is proposed. First, a commercial biomimetic polycarbonate (PCTE) microfiltration membrane is employed as the capture interface for heterogenous CTCs. Meanwhile, differential detection of the captured CTCs is realized by preparing two distinct CdTe quantum dots (QDs) with red and green emissions, attached with EpCAM and Vimentin aptamers, respectively. For combined analysis, a polydimethylsiloxane (PDMS) chip with simple structure is designed, which integrates the membrane capture and QDs-based phenotype detection of CTCs. This chip not only implements the analysis of the number of CTCs down to 2 cells mL-1, but enables EMT process tracking according to the specific signals of the two QDs. Finally, this method is successfully applied to inspect the correlations of numbers or proportions of heterogenous CTCs in 94 NSCLS patients with disease stage and whether there is distant metastasis.

2.
Materials (Basel) ; 17(8)2024 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-38673160

RESUMO

Welded steel plates are widely used in various structural applications, and the presence of inclined welds is often encountered in practical scenarios. Carbon fiber reinforced polymer (CFRP) has been proven to be effective for strengthening steel structures. However, the behavior of CFRP-strengthened welded steel plates with inclined welds, particularly considering the influence of welding residual stress, is limited. This paper aims to investigate the tensile behavior of CFRP-strengthened welded Q355 steel plates with inclined welds considering welding residual stress (WRS). First, WRS data were obtained by the X-ray diffraction (XRD) method at different locations. The maximum tensile and compressive residual stresses are 0.39 and 0.14 times the yield strength of the steel, respectively. Then, finite element models were established to investigate the effects of weld angles, weld width, and height on the WRS distribution of welded steel plates. Finally, the tensile performance of CFRP-strengthened welded plates with WRS was studied by numerical simulation. The results showed that the weld angles have little effect on the distribution pattern of residual stress but significantly affect the peak tensile WRS. When the weld angle changes from 0° to 60°, the peak tensile WRS decreases significantly from 0.32 to 0.06 times the yield strength of steel; furthermore, the influence of weld width and height on WRS is relatively limited. Under tension loading, the maximum stress occurs near the weld. The ends of the weld enter the yielding state later than the middle part of the weld due to the distribution of the WRS. As the weld angle increases and the length of the weld increases, the stress in the weld zone decreases, while the stress in the base material zone correspondingly increases. In addition, CFRP strengthening can reduce the magnitude of stress. This study provides preliminary references for understanding the tensile behavior of CFRP-strengthened welded steel plates with inclined welds.

3.
Bioresour Technol ; 400: 130691, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38599347

RESUMO

Indole acetic acid (IAA) as a plant hormone, was one of the valuable products of anaerobic fermentation. However, the enriching method remained unknown. Moreover, whether zero valent iron (ZVI) could enhance IAA production was unexplored. In this work, IAA producing bacteria Klebsiella (63 %) was enriched successfully. IAA average production rate and concentration were up to 3 mg/L/h and 56 mg/L. With addition of 1 g/L ZVI, IAA average production rate and concentration was increased for 2 and 3 folds. Mechanisms indicated ZVI increased Na+K+-ATP activity and electron transport activity for 2 folds and 1 fold. Moreover, macro transcription determined indole pyruvate pathway activity like primary-amine oxidase, indole pyruvate decarboxylase and aldehyde dehydrogenase were increased for 146 %, 187 %, and 557 %, respectively. Therefore, ZVI was suitable for enhancement IAA production from mixed culture anaerobic fermentation.


Assuntos
Fermentação , Ácidos Indolacéticos , Ferro , Triptofano , Ácidos Indolacéticos/metabolismo , Triptofano/metabolismo , Anaerobiose , Ferro/metabolismo , Klebsiella/metabolismo
4.
Nat Commun ; 15(1): 2760, 2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38553448

RESUMO

The cGAS-STING pathway plays a crucial role in anti-tumoral responses by activating inflammation and reprogramming the tumour microenvironment. Upon activation, STING traffics from the endoplasmic reticulum (ER) to Golgi, allowing signalling complex assembly and induction of interferon and inflammatory cytokines. Here we report that cGAMP stimulation leads to a transient decline in ER cholesterol levels, mediated by Sterol O-Acyltransferase 1-dependent cholesterol esterification. This facilitates ER membrane curvature and STING trafficking to Golgi. Notably, we identify two cholesterol-binding motifs in STING and confirm their contribution to ER-retention of STING. Consequently, depletion of intracellular cholesterol levels enhances STING pathway activation upon cGAMP stimulation. In a preclinical tumour model, intratumorally administered cholesterol depletion therapy potentiated STING-dependent anti-tumoral responses, which, in combination with anti-PD-1 antibodies, promoted tumour remission. Collectively, we demonstrate that ER cholesterol sets a threshold for STING signalling through cholesterol-binding motifs in STING and we propose that this could be exploited for cancer immunotherapy.


Assuntos
Proteínas de Membrana , Neoplasias , Humanos , Proteínas de Membrana/metabolismo , Transdução de Sinais/fisiologia , Interferons/metabolismo , Nucleotidiltransferases/metabolismo , Neoplasias/terapia , Neoplasias/metabolismo , Retículo Endoplasmático/metabolismo , Microambiente Tumoral
5.
Sci Rep ; 14(1): 5486, 2024 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-38448552

RESUMO

Varicose veins of the lower extremities (VVLEs) are prevalent globally. This study aims to identify prognostic factors and develop a prediction model for recurrence survival (RS) in VVLEs patients after surgery. A retrospective analysis of VVLEs patients from the Third Hospital of Nanchang was conducted between April 2017 and March 2022. A LASSO (Least Absolute Shrinkage and Selection Operator) regression model pinpointed significant recurrence predictors, culminating in a prognostic nomogram. The model's performance was evaluated by C-index, receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA). The LASSO regression identified seven predictors for the nomogram predicting 1-, 2-, and 5-year RS. These predictors were age, body mass index (BMI), hypertension, diabetes, the Clinical Etiological Anatomical Pathophysiological (CEAP) grade, iliac vein compression syndrome (IVCS), and postoperative compression stocking duration (PCSD). The nomogram's C-index was 0.716, with AUCs (Area Under the Curve scores) of 0.705, 0.725, and 0.758 for 1-, 2-, and 5-year RS, respectively. Calibration and decision curve analyses validated the model's predictive accuracy and clinical utility. Kaplan-Meier analysis distinguished between low and high-risk groups with significant prognostic differences (P < 0.05). This study has successfully developed and validated a nomogram for predicting RS in patients with VVLEs after surgery, enhancing personalized care and informing clinical decision-making.


Assuntos
Nomogramas , Varizes , Humanos , Prognóstico , Estudos Retrospectivos , Extremidade Inferior , Varizes/cirurgia
6.
Plants (Basel) ; 13(5)2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38475576

RESUMO

Meloidogyne javanica is one of the most widespread and economically important sedentary endoparasites. In this study, a comparative transcriptome analysis of M. javanica between pre-parasitic second-stage juveniles (Pre-J2) and parasitic juveniles (Par-J3/J4) was conducted. A total of 48,698 unigenes were obtained, of which 18,826 genes showed significant differences in expression (p < 0.05). In the differentially expressed genes (DEGs) from transcriptome data at Par-J3/J4 and Pre-J2, a large number of unigenes were annotated to the C-type lectin (CTL, Mg01965), the cathepsin L-like protease (Mi-cpl-1), the venom allergen-like protein (Mi-mps-1), Map-1 and the cellulase (endo-ß-1,4-glucanase). Among seven types of lectins found in the DEGs, there were 10 CTLs. The regulatory roles of Mj-CTL-1, Mj-CTL-2 and Mj-CTL-3 in plant immune responses involved in the parasitism of M. javanica were investigated. The results revealed that Mj-CTL-2 could suppress programmed cell death (PCD) triggered by Gpa2/RBP-1 and inhibit the flg22-stimulated ROS burst. In situ hybridization and developmental expression analyses showed that Mj-CTL-2 was specifically expressed in the subventral gland of M. javanica, and its expression was up-regulated at Pre-J2 of the nematode. In addition, in planta silencing of Mj-CTL-2 substantially increased the plant resistance to M. javanica. Moreover, yeast co-transformation and bimolecular fluorescence complementation assay showed that Mj-CTL-2 specifically interacted with the Solanum lycopersicum catalase, SlCAT2. It was demonstrated that M. javanica could suppress the innate immunity of plants through the peroxide system, thereby promoting parasitism.

7.
Biomed Opt Express ; 15(3): 1709-1718, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38495691

RESUMO

This study presents the development of an in-situ background-free Raman fiber probe, employing two customized double-cladding anti-resonant hollow-core fibers (AR-HCFs). The Raman background noise measured in the AR-HCF probe is lower than that of a conventional multi-mode silica fiber by two orders of magnitude. A plug-in device for fiber coupling optics was designed that was compatible with a commercially available confocal Raman microscope, enabling in-situ Raman detection. The numerical aperture (NA) of both AR-HCF claddings exceeds 0.2 substantially enhancing the collection efficiency of Raman signals at the distal end of the fiber probe. The performance of our Raman fiber probe is demonstrated by characterizing samples of acrylonitrile-butadiene-styrene (ABS) plastics, alumina ceramics, and ethylene glycol solution.

8.
Opt Lett ; 49(4): 989-992, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38359243

RESUMO

We demonstrated an efficient way to enhance and flatten the emission cross sections of Er3+ ions at the L-band in the silicate fiber amplifier by increasing Mg2+ (up to 22.5 mol%) with high field strength. High values of Er3+ concentration, lifetime, and L-band emission cross section were achieved in our silicate fibers. Particularly, the flatness at the L-band was achieved to be 0.8 dB, and a high gain coefficient at 1625 nm (4.7 dB/m) was demonstrated by pumping meter-scale Er-silicate fibers. The as-prepared Er-silicate fibers are attractive for the L-band fiber amplifier.

9.
Phys Chem Chem Phys ; 26(5): 3869-3879, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38226609

RESUMO

Rare-earth-doped silica-based composite glasses (Re-SCGs) are widely used as high-quality laser gain media in defense, aerospace, energy, power, and medical applications. The variable regional chemical environments of Re-SCGs can induce new photoluminescence properties of rare-earth ions but can cause the selective aggregation of rare-earth ions, limiting the application of Re-SCGs in the field of high-power lasers. Here, topological engineering is proposed to adjust the degree of cross-linking of phase-separation network chains in Re-SCGs. A combination of experimental and theoretical characterization techniques suggested that the selective aggregation of rare-earth ions originates from the formation of phase-separated structures in glasses. The decomposition of nanoscale phase separation structures to the sub-nanometer scale, enabled by incorporating Al3+ ions, not only maintains the high luminescence efficiency of rare earth ions but also increases light transmittance and reduces light scattering. Furthermore, our investigation encompassed the exploration of the inhibitory mechanism of Al3+ ions on phase-separation structures, as well as their influence on the spectral characteristics of Re-SCGs. This work provides a new design concept for composite glass materials doped with rare-earth ions and could broaden their application in the field of high-power lasers.

10.
J Gynecol Oncol ; 35(1): e10, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37857565

RESUMO

OBJECTIVE: To compare the efficacy and safety of neoadjuvant chemotherapy combined with concurrent chemoradiotherapy (NACT+CCRT) vs. concurrent chemoradiotherapy (CCRT) in locally advanced cervical cancer (LACC) patients with large tumor masses. METHODS: LACC patients with localized tumor diameter >4 cm, were randomly allocated in an unblinded 1:1 ratio to NACT+CCRT or CCRT groups. Patients in the NACT+CCRT group were given paclitaxel combined with cisplatin (TP) NACT every 3 weeks for 2 cycles, followed by CCRT, with the chemotherapy regimen the same as for NACT. CCRT group were given CCRT with the same as for NACT. RESULTS: From March 1, 2019, to June 30, 2021, 146 patients were included in the final analysis. Sixty-eight (93.2%) patients in the NACT+CCRT group and 66 (90.4%) patients in the CCRT group completed the expected treatment course. The complete response (CR) rate in the NACT+CCRT group was significantly higher than in the CCRT group (87.7% vs. 67.6%, χ²=54.540, p=0.000). In the NACT+CCRT group, the 1- and 2-year overall survival (OS) rates were significantly higher than those in the CCRT group (96% vs. 89% and 89% vs. 79%, χ²=5.737, p=0.017). Additionally, the rate of recurrences and distant metastases was significantly lower in the NACT+CCRT group than in the CCRT group (4.11% vs. 7.35%, χ²=4.059, p=0.021). Most treatment-related adverse events in both groups were grade 3. CONCLUSION: Compared to CCRT, NACT+CCRT might improve the treatment completion rate, increase CR rate and 1- and 2-year OS rates, and reduce distant metastases rate for LACC patients with large tumor masses.


Assuntos
Quimiorradioterapia , Terapia Neoadjuvante , Neoplasias do Colo do Útero , Feminino , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Quimiorradioterapia/efeitos adversos , Cisplatino/efeitos adversos , Terapia Neoadjuvante/efeitos adversos , Estadiamento de Neoplasias , Resultado do Tratamento , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/terapia
11.
Eur J Cancer Prev ; 33(2): 141-151, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37751366

RESUMO

OBJECTIVE: Risk perception and disease cognition may influence the efficiency of lung cancer screening by affecting the participation rate. There is still some uncertainty regarding the association between risk perception and disease cognition and how they affect participation in lung cancer screening. Therefore, we explored the influence of risk perception and disease cognition on the willingness to participate in screening among people at high risk of lung cancer. METHODS: Subjects with high-risk factors for lung cancer were recruited in Lu'an City, Anhui Province, China. Questionnaires were used to determine their demographic characteristics, risk perception, disease cognition, and willingness to engage in screening. RESULTS: Of the 1955 subjects with high risk factors for lung cancer, 1136 (58.12%) were willing to participate in lung cancer screening. Univariable and multivariable analyses showed that disease cognition ( adj OR = 2.012, 95% CI: 1.528-2.649, P  = 0.000), cognitive risk ( adj OR = 7.661, 95% CI: 6.049-9.704, P  = 0.000), and affective risk ( adj OR = 5.964, 95% CI: 4.552-7.815, P  = 0.000) were significant factors in promoting screening participation. For those with moderate risk perception, improving disease cognition was a key approach to increase screening participation. CONCLUSION: This study elucidated the relationship between various factors and lung cancer screening participation and proposed a feasible route for the screening implementation, providing a theoretical basis to further improve the participation rate and efficiency of lung cancer screening.


Assuntos
Detecção Precoce de Câncer , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/epidemiologia , Fatores de Risco , Inquéritos e Questionários , Cognição , Percepção
12.
Psychiatry Res ; 331: 115612, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38039652

RESUMO

The epidemiology of schizophrenia has been reported in many countries. However, due to the limitations of those studies, the findings cannot be generalized to other parts of the world, especially in China. In this study, the incidence, prevalence, and mortality of schizophrenia in Shandong, China were calculated using data from the National Severe Mental Disorder Registration System collected between 2016 and 2020 and census data from 2010 to 2020. The overall incidence decreased from 9.61 per 100,000 in 2016 to 4.40 per 100,000 in 2020, the aggregate prevalence was approximately 3.20 per 1000, and the overall mortality ranged from 6.17 per 100,000 to 7.71 per 100,000. The evidence from this study indicated that the incidence, prevalence, and mortality of schizophrenia were higher in rural areas than in urban areas. Females had higher incidence, prevalence, and mortality than males. This study provided epidemiological information on schizophrenia and opened avenues for future research.


Assuntos
Esquizofrenia , Feminino , Masculino , Humanos , Esquizofrenia/epidemiologia , Incidência , Prevalência , População Rural , População Urbana , Sistema de Registros , China/epidemiologia
13.
Lipids Health Dis ; 22(1): 191, 2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-37950240

RESUMO

BACKGROUND: Low-carbohydrate diet (LCD) is effective for weight loss and glycaemic control in humans. Here, the study aimed to explore the effects of LCD/high-fat diet (HFD) in both humans and mice. METHODS: Twenty-two overweight or obese participants received LCD for 3 weeks. Based on carbohydrate intake > 10% or ≤ 10% of calories, the participants were divided into moderate LCD (MLCD) and very LCD (VLCD) groups. The participants completed a 10-question food preference survey. Meanwhile, C57BL/6J mice were assigned to five groups: chow diet (CD, 10% fat), HFD with 60%, 70%, and 75% fat from cocoa butter (HFD-C), and HFD with 60% fat from lard (HFD-L) and fed for 24 weeks. Eight mice were acclimatised for the food-choice test. RESULTS: LCD decreased the total energy intake in humans. The VLCD group showed greater weight loss and better glycaemic control than the MLCD group. A food preference survey showed that 65% of participants tended to choose high-carbohydrate foods. In mice, HFD resulted in energy overconsumption, obesity, and metabolic disorders. When CD and HFD-L were administered simultaneously, mice rarely consumed CD. In the HFD-C groups, the energy intake and body weight increased with increasing dietary fat content. Compared with the HFD-C group, the HFD-L group consumed more energy and had poorer metabolism. CONCLUSIONS: Lower carbohydrate intake contributed to lower energy intake and improved metabolism in humans. In mice, diets with a higher proportion of fat become more attractive and obesogenic by fixing the fat sources. Since the mice preferred lard to cocoa butter, lard induced excess energy intake and poorer metabolism. Different food preferences may be the underlying mechanism behind the opposite effects of the LCD/HFD in humans and mice. TRIAL REGISTRATION: The clinical trial was registered with the Chinese Clinical Trial Registry ( www.chictr.org.cn ). The registration number is ChiCTR1800016786. All participants provided written informed consent prior to enrolment.


Assuntos
Dieta com Restrição de Gorduras , Dieta Hiperlipídica , Humanos , Camundongos , Animais , Dieta Hiperlipídica/efeitos adversos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Ingestão de Energia , Redução de Peso , Carboidratos
14.
Opt Express ; 31(20): 33741-33752, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37859147

RESUMO

We demonstrate a high ytterbium concentration Yb/Al/P/Ce co-doped silica fiber by conventional modified chemical vapor deposition (MCVD) technology and solution doping process. The fiber has a Yb concentration of about 2.5 wt%, and the corresponding core absorption coefficient is measured to be ∼1400 dB/m at 976 nm. The gain coefficient was measured to be approximately 1.0 dB/cm. It is found that the Yb/Al/P/Ce co-doped silica shows a lower photodarkening-induced equilibrium loss of 52 dB/m at 633 nm than the Yb/Al/P co-doped silica fiber of 117 dB/m. Using the heavily Yb3+-doped silica fiber, a compact and robust ultrashort cavity single-frequency fiber laser was achieved with a maximum output power of 75 mW and a linewidth of 14 kHz. Furthermore, a compact passively mode-locked fiber laser (MLFL) with a repetition rate of 1.23 GHz was also proposed using our developed Yb-doped fiber. The laser properties of the proposed lasers were systematically investigated, demonstrating the superior performance of this fiber in terms of photodarkening resistance and ultrashort-cavity laser application. Furthermore, utilizing an all-fiber structure based on silica-based fiber offers the significant advantage of high stability and reliability.

15.
Int J Pharm X ; 6: 100199, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37521247

RESUMO

The aim of this study was to design a chitosan-coated hollow tin dioxide nanosphere (CS-HSn) for loading febuxostat (FEB) using an adsorption method to obtain a sustained-release system (CS-HSn-FEB) to improve the oral bioavailability of FEB. The morphological characteristics of hollow tin dioxide nanospheres (HSn) and CS-HSn were analyzed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The hemolysis test and CCK-8 test were used to assess the biosafety of HSn and CS-HSn. Powder X-ray diffraction (PXRD) and differential scanning thermal analysis (DSC) were performed on CS-HSn-FEB to analyze the drug presence status. The dissolution behavior and changes in plasma drug concentration of CS-HSn-FEB were evaluated in vitro and in vivo. Sections of intestinal tissues from SD rats were obtained to observe whether chitosan could increase the distribution of nanoparticles in the intestinal tissues. The results showed that FEB was present in CS-HSn in an amorphous state. Moreover, CS-HSn, with good biosafety, significantly improved the water solubility and oral absorption of FEB, indicating that CS-HSn has great potential to improve the intestinal absorption and oral bioavailability of insoluble drugs.

16.
Polymers (Basel) ; 15(13)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37447570

RESUMO

Glass fiber-reinforced polymer (GFRP) rebars are commonly used as an alternative to conventional steel reinforcement in a variety of structural applications due to their superior low cost, strength-to-weight ratio, and durability. However, their mechanical properties after exposure to elevated temperatures, particularly in fire-prone environments, remain a significant concern. To address this concern, the present study focuses on investigating the residual tensile behavior, specifically the tensile strength and elastic modulus, of GFRP rebars exposed to high temperatures that are realistically encountered during fire incidents. The temperature range considered in this analysis spans from 100 °C to 400 °C, with a heating rate of 20 °C/min. The fire duration of 1 h is used. This comprehensive analysis is essential for enhancing our understanding of the performance and applicability of GFRP rebars in fire-prone environments. Based on their actual application in the construction industry, five specimens of three different rebar sizes (16, 20, and 25 mm) were examined for the effect of rebar size on tensile behavior after fire exposure. In addition, the effects were investigated of air- and water-cooling methods on residual tensile behavior. The nominal tensile strength, elastic modulus, and ultimate strain of GFRP rebars at ambient temperature are 930 MPa, 50.2 GPa and 1.85%, respectively. The test results indicated that as the temperature increased to 400 °C, the ultimate tensile strength of the GFRP bars decreased by up to 55%, while the ultimate strain increased by up to 44%, regardless of the cooling method. In addition, when rebars of sizes 16-25 mm were subjected to a 400 °C fire treatment, the smaller the rebar, the greater the percentage of ultimate tensile and strain reduction. These findings hold great significance for the utilization of GFRP bars within the construction industry. This study offers valuable insights into the design of fire-resilient structures, emphasizing the importance of considering rebar size and cooling methods due to their impact on the post-fire tensile strength and strain of GFRP rebars.

17.
J Agric Food Chem ; 71(23): 8998-9008, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37260384

RESUMO

Plant bioactive metabolites such as flavonoids are usually present in glycosylated forms by the attachment of various sugar groups. In this study, a catalytically flexible and reversible glycosyltransferase (HtUGT72AS1) was cloned and characterized from Helleborus thibetanus. HtUGT72AS1 could directly accept six sugar donors (UDP-glucose/-arabinose/-galactose/-xylose/-N-acetylglucosamine/-rhamnose) to catalyze the 3-OH glycosylation of flavonols. It also catalyzed the 4' and 7-OH glycosylation of other types of flavonoids, which lacked the 3-OH group. Additionally, the HtUGT72AS1-catalyzed reaction was highly reversible when using 2-chloro-4-nitrophenyl glycosides as substrates, which could be used for one-pot or coupled production of bioactive glycosides. It is the first reported UGT for the synthesis of arabinosides and galactosides using a transglycosylation platform. Based on structural modeling and mutagenetic analysis, the mutation of Tyr377 to Ara enhanced the catalytic efficiency of HtUGT72AS1 toward UDP-N-acetylglucosamine, and the V146S mutant gained an improvement in the regioselectivity toward 7-OH of flavonoids.


Assuntos
Acetilglucosamina , Glicosiltransferases , Glicosiltransferases/metabolismo , Glicosídeos/química , Flavonoides/química , Plantas/metabolismo , Catálise , Açúcares , Difosfato de Uridina
18.
Opt Express ; 31(13): 21870-21880, 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37381274

RESUMO

In this work, multi-mode anti-resonant hollow-core fiber (AR-HCF) with 18 fan-shaped resonators is fabricated and characterized. The ratio of core diameter over transmitted wavelengths in the lowest transmission band is up to 85. The measured attenuation at 1 µm wavelength is below 0.1 dB/m and the bend loss below 0.2 dB/m at a bend radius smaller than 8 cm. Modal content of the multi-mode AR-HCF is characterized using the S2 imaging technique and seven LP-like modes in total are identified using a 23.6 meter fiber length. Multi-mode AR-HCFs for longer wavelengths are fabricated by scaling up the same design, extending the transmission window beyond 4 µm wavelength. Low-loss multi-mode AR-HCF could find applications in the delivery of high-power laser light with a medium beam quality, where higher coupling efficiency and laser damage threshold are expected.

19.
Opt Express ; 31(8): 13307-13316, 2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37157470

RESUMO

Nd3+-doped three-level (4F3/2-4I9/2) fiber lasers with wavelengths in the range of 850-950 nm are of considerable interest in applications such as bio-medical imaging and blue and ultraviolet laser generation. Although the design of a suitable fiber geometry has enhanced the laser performance by suppressing the competitive four-level (4F3/2-4I11/2) transition at ∼1 µm, efficient operation of Nd3+-doped three-level fiber lasers still remains a challenge. In this study, taking a developed Nd3+-doped silicate glass single-mode fiber as gain medium, we demonstrate efficient three-level continuous-wave lasers and passively mode-locked lasers with a gigahertz (GHz) fundamental repetition rate. The fiber is designed using the rod-in-tube method and has a core diameter of 4 µm with a numerical aperture of 0.14. In a short 4.5-cm-long Nd3+-doped silicate fiber, all-fiber CW lasing in the range of 890 to 915 nm with a signal-to-noise ratio (SNR) greater than 49 dB is achieved. Especially, the laser slope efficiency reaches 31.7% at 910 nm. Furthermore, a centimeter-scale ultrashort passively mode-locked laser cavity is constructed and ultrashort pulse at 920 nm with a highest GHz fundamental repetition is successfully demonstrated. Our results confirm that Nd3+-doped silicate fiber could be an alternative gain medium for efficient three-level laser operation.

20.
J Glob Health ; 13: 04059, 2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37227033

RESUMO

Background: Published guidelines on decision-making and resuscitation of extremely preterm infants primarily focus on high-income countries. For rapidly industrializing ones like China, there is a lack of population-based data for informing prenatal management and practice guidelines. Methods: The Sino-northern Neonatal Network conducted a prospective multi-centre cohort study between 1 January 2018 and 31 December 2021. Infants with a gestational age (GA) between 22 (postnatal age in days = 0) and 28 (postnatal age in days = 6) admitted to 40 tertiary NICUs in northern China were included and evaluated for death or severe neurological injury before discharge. Results: For all extremely preterm infants (n = 5838), the proportion of admission to the neonatal was 4.1% at 22-24 weeks, 27.2% at 25-26 weeks, and 75.2% at 27 and 28 weeks. Among 2228 infants admitted to the NICU, 216 (11.1%) were still elected for withdrawal of care (WIC) due to non-medical factors. Survival rates without severe neurological injury were 6.7% for infants at 22-23 weeks, 28.0% at 24 weeks, 56.7% at 24 weeks, 61.7% at 25 weeks, 79.9% at 26 weeks, and 84.5% at 27 and 28 weeks. Compared with traditional criterion at 28 weeks, the relative risk for death or severe neurological injury were 1.53 (95% confidence interval (CI) = 1.26-1.86) at 27 weeks, 2.32 (95% CI = 1.73-3.11) at 26 weeks, 3.62 (95% CI = 2.43-5.40) at 25 weeks, and 8.91 (95% CI = 4.69-16.96) at 24 weeks. The NICUs with higher proportion of WIC also had a higher rate of death or severe neurological injury after maximal intensive care (MIC). Conclusions: Compared to the traditional threshold of 28 weeks, more infants received MIC after 25 weeks, leading to significant increases in survival rates without severe neurological injury. Therefore, the resuscitation threshold should be gradually adjusted from 28 to 25 weeks based on reliable capacity. Registration: China Clinical Trials Registry. ID: ChiCTR1900025234.


Assuntos
Lactente Extremamente Prematuro , Ressuscitação , Humanos , Masculino , Feminino , Taxa de Sobrevida , Estudos Prospectivos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , China
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...