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1.
Opt Lett ; 49(7): 1660-1663, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38560830

RESUMO

We report a high-performance wavelength-switchable near-infrared Pr3+:LiYF4 (Pr:YLF) laser by InGaN laser diode (LD) pumping. The 895, 922, and 924 nm lasers with low emission cross sections in the Pr:YLF crystal have been successfully realized using a birefringent filter Lyot as well as designing and optimizing optical thin films and the laser resonant cavity. The maximum output powers of the 895, 922, and 924 nm lasers are 2.01, 1.92, and 1.95 W, respectively. As far as we know, these are the highest power for Pr:YLF lasers at 895, 922, and 924 nm so far. The beam quality M x2 and M y2 factors are measured to be 1.85 and 1.71 at 895 nm, 1.94 and 1.67 at 922 nm, and 1.76 and 1.60 at 924 nm, respectively. The laser output power fluctuates within ±3%. In addition, the transmittance of the Lyot is theoretically calculated to achieve laser wavelength switching. The successful realization of the wavelength-switchable watt-level continuous wave near-infrared Pr:YLF laser can provide many practical applications in biomedicine and other fields.

2.
Angew Chem Int Ed Engl ; 63(20): e202401498, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38499469

RESUMO

Herein, multiple types of chiral Os(II) complexes have been designed to address the appealing yet challenging asymmetric C(sp3)-H functionalization, among which the Os(II)/Salox species is found to be the most efficient for precise stereocontrol in realizing the asymmetric C(sp3)-H amidation. As exemplified by the enantioenriched pyrrolidinone synthesis, such tailored Os(II)/Salox catalyst efficiently enables an intramolecular site-/enantioselective C(sp3)-H amidation in the γ-position of dioxazolone substrates, in which benzyl, propargyl and allyl groups bearing various substituted forms are well compatible, affording the corresponding chiral γ-lactam products with good er values (up to 99 : 1) and diverse functionality (>35 examples). The unique performance advantage of the developed chiral Os(II)/Salox system in terms of the catalytic energy profile and the chiral induction has been further clarified by integrated experimental and computational studies.

3.
Anal Chem ; 95(42): 15745-15754, 2023 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-37842978

RESUMO

Exosomal surface glycan reveals the biological function and molecular information on the protein, especially in indicating the pathogenesis of certain diseases through monitoring of specific protein glycosylation accurately. However, in situ and nondestructive measurement techniques for certain Exosomal glycoproteins are still lacking. In this work, combined with on-chip purification, we designed a proximity ligation assay-induced rolling circle amplification (RCA) strategy for highly sensitive identification of Exosomal protein-specific glycosylation based on a couple of proximity probes to target Exosomal protein and the protein-specific glycosylation site. Benefiting from efficient separation, scalable dual-recognition, and proximity-triggered RCA amplification, the proposed strategy could convert different protein-specific glycan levels to prominent changes in absorbance signals, resulting in accurate quantification of specific glycosylated Exosomal protein. When detecting the glycosylated PD-L1 on MDA-MB-231 exosomes and glycosylated PTK7 on HepG2 exosomes, the detection limits were calculated to be as low as 1.04 × 104 and 2.759 × 103 particles/mL, respectively. In addition, we further expand the dual-recognition site to investigate the potential correlation of Exosomal glycosylation with polarization of THP-1 cells toward the tumor-suppressive M1 phenotype. Overall, this strategy provides a universal tool for multiple analyses of diverse protein-specific glycosylated exosomes, exhibiting enormous potential to explore exosome function and search for new early diagnosis markers.


Assuntos
Exossomos , Proteínas , Glicosilação , Proteínas/análise , Polissacarídeos/metabolismo , Exossomos/química
4.
Eur Respir J ; 61(1)2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35926878

RESUMO

BACKGROUND: Variable clinical outcomes are reported with fungal sensitisation in chronic obstructive pulmonary disease (COPD), and it remains unclear which fungi and what allergens associate with the poorest outcomes. The use of recombinant as opposed to crude allergens for such assessment is unknown. METHODS: A prospective multicentre assessment of stable COPD (n=614) was undertaken in five hospitals across three countries: Singapore, Malaysia and Hong Kong. Clinical and serological assessment was performed against a panel of 35 fungal allergens including crude and recombinant Aspergillus and non-Aspergillus allergens. Unsupervised clustering and topological data analysis (TDA) approaches were employed using the measured sensitisation responses to elucidate if sensitisation subgroups exist and their related clinical outcomes. RESULTS: Aspergillus fumigatus sensitisation was associated with increased exacerbations in COPD. Unsupervised cluster analyses revealed two "fungal sensitisation" groups. The first was characterised by Aspergillus sensitisation and increased exacerbations, poorer lung function and worse prognosis. Polysensitisation in this group conferred even poorer outcome. The second group, characterised by Cladosporium sensitisation, was more symptomatic. Significant numbers of individuals demonstrated sensitisation responses to only recombinant (as opposed to crude) A. fumigatus allergens f 1, 3, 5 and 6, and exhibited increased exacerbations, poorer lung function and an overall worse prognosis. TDA validated these findings and additionally identified a subgroup within Aspergillus-sensitised COPD of patients with frequent exacerbations. CONCLUSION: Aspergillus sensitisation is a treatable trait in COPD. Measuring sensitisation responses to recombinant Aspergillus allergens identifies an important patient subgroup with poor COPD outcomes that remains overlooked by assessment of only crude Aspergillus allergens.


Assuntos
Aspergillus fumigatus , Doença Pulmonar Obstrutiva Crônica , Humanos , Aspergillus fumigatus/genética , Alérgenos , Estudos Prospectivos , Imunoglobulina E , Doença Pulmonar Obstrutiva Crônica/complicações , Aspergillus
5.
Small ; : e2308716, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38072769

RESUMO

The selective quantification of copper ions (Cu2+ ) in biosamples holds great importance for disease diagnosis, treatment, and prognosis since the Cu2+ level is closely associated with the physiological state of the human body. While it remains a long-term challenge due to the extremely low level of free Cu2+ and the potential interference by the complex matrices. Here, a pore-engineered hydrogen-bonded organic framework (HOF) fluorosensor is constructed enabling the ultrasensitive and highly selective detection of free Cu2+ . Attributing to atomically precise functionalization of active amino "arm" within the HOF pores and the periodic π-conjugated skeleton, this porous HOF fluorosensor affords high affinity toward Cu2+ through double copper-nitrogen (Cu─N) coordination interactions, resulting in specific fluorescence quenching of the HOF as compared with a series of substances ranging from other metal ions, metabolites, amino acids to proteins. Such superior fluorescence quenching effect endows the Cu2+ quantification by this new HOF sensor with a wide linearity of 50-20 000 nm, a low detection limit of 10 nm, and good recoveries (89.5%-115%) in human serum matrices, outperforming most of the reported approaches. This work highlights the practicability of hydrogen-bonded supramolecular engineering for designing facile and ultrasensitive biosensors for clinical free Cu2+ determination.

6.
Analyst ; 148(20): 4954-4966, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37721099

RESUMO

Exosomes are a kind of extracellular vesicles, which play a significant role in intercellular communication and molecular exchange. Cancer-derived exosomes are potential and ideal biomarkers for the early diagnosis and treatment monitoring of cancers because of their abundant biological information and contribution to the interaction between cancer cells and the tumor microenvironment. However, there are a number of drawbacks, such as low sensitivity and tedious steps, in conventional detection techniques. Furthermore, exosome quantification is not enough to accurately distinguish cancer patients from healthy individuals. Therefore, developing efficient, accurate, and inexpensive exosome surface protein analysis techniques is necessary and critical. In recent years, a considerable number of researchers have presented novel detection strategies in this field. This review summarizes the recent progress in quantitative technologies for the analysis of cancer-related exosome proteins, mainly including the detection methods based on aptamers, nanomaterials, and antibodies, discusses a roadmap for future developments, and aims to offer an innovative perspective of exosome research.


Assuntos
Exossomos , Neoplasias , Humanos , Exossomos/metabolismo , Proteínas/metabolismo , Biomarcadores/metabolismo , Neoplasias/metabolismo , Anticorpos/metabolismo , Microambiente Tumoral
7.
J Ultrasound Med ; 42(7): 1413-1422, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36715025

RESUMO

In knee osteoarthritis (KOA), timely and accurate assessment of the severity is essential to help orthopedic surgeons determine the most appropriate therapeutic strategies and evaluate disease outcomes and responses for corresponding treatments. In KOA, musculoskeletal ultrasonography (MSUS) could effectively help detect various abnormalities, including synovitis, osteophytes, and cartilage damage. Further, MSUS could be used to monitor the response to different therapies in KOA, to guide local diagnostic and therapeutic procedures. In the future, applications based on continuously evolving US tools could enhance the clinical utility of MSUS in KOA.


Assuntos
Osteoartrite do Joelho , Osteófito , Sinovite , Humanos , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/terapia , Ultrassonografia/métodos , Articulação do Joelho/diagnóstico por imagem
8.
Perfusion ; 38(1): 178-185, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-34541941

RESUMO

OBJECTIVE: To investigate the effects of glucose-free and glucose-containing dialysates during dialysis in maintenance hemodialysis (MHD) patients by the prospective cross-over study, and detect glucose control methods in MHD patients. METHODS: A total of 66 MHD 18-75 years old patients in our hospital from Nov. 2019 to Mar. 2020 were recruited. All patients underwent HD with 4 hours per time, three times per week. Glucose-free dialysate (glucose-free group) and then 5.55 mmol/L glucose-containing dialysate (glucose-5.55 group) were used alternately in dialysis. The demographics and parameters of pre- and post-dialysis were recorded. RESULTS: A total of 60 patients were analyzed, and 28 patients among them had type 2 diabetes. Serum glucose pre and post dialysis were 8.64 ± 4.18 mmol/L versus 5.74 ± 1.82 mmol/L (p < 0.01) in glucose-free dialysate, and 9.31 ± 4.89 mmol/L versus 7.80 ± 2.59 mmol/L (p < 0.01) in glucose-5.55 dialysate. The post-dialysis blood glucose of glucose-free group was lower than glucose-5.55 group (5.74 ± 1.82 vs 7.80 ± 2.59, p < 0.01). About 18 (30.00%) patients in glucose-free group and 1 patient (1.67%) in glucose-5.55 group whose blood glucose was lower than 4.44 mmol/L (p < 0.01). About 29 patients (48.33%) in glucose-free group and 17 patients (28.33%; p = 0.02) in glucose-5.55 group have hunger feeling. Serum sodium level in the glucose-free group was higher than that in Glucose-5.55 group (137.92 ± 1.64 vs 136.70 ± 1.64, p < 0.01). Post-dialysis blood glucose had no significant differences between patients not using diabetes-related medication (13 patients) and patients using diabetes-related medication (15 patients) in glucose-free group (7.13 ± 1.78 mmol/L vs 6.08 ± 2.84 mmol/L, p = 0.23) and glucose-5.55 group (9.22 ± 2.59 mmol/L vs 9.35 ± 2.88 mmol/L, p = 0.90). CONCLUSIONS: Glucose-free and glucose-5.55 dialysate both decrease the blood glucose post-dialysis. Dialysates containing 5.55 mmol/L glucose can reduce the incidence of hypoglycemia and lower serum sodium, but have no effect on blood pressure during dialysis. Stopping insulin and oral anti-diabetic drugs once before dialysis may not affect the control of blood glucose.


Assuntos
Diabetes Mellitus Tipo 2 , Falência Renal Crônica , Adolescente , Adulto , Idoso , Humanos , Pessoa de Meia-Idade , Adulto Jovem , Glicemia , Estudos Cross-Over , Diabetes Mellitus Tipo 2/tratamento farmacológico , Soluções para Diálise/farmacologia , Soluções para Diálise/uso terapêutico , Glucose/farmacologia , Glucose/uso terapêutico , Soluções para Hemodiálise , Falência Renal Crônica/terapia , Estudos Prospectivos , Diálise Renal/métodos , Sódio
9.
Anal Chem ; 94(21): 7703-7712, 2022 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-35575685

RESUMO

Exosomes are lipid bilayer extracellular vesicles secreted by various types of cells and inherit abundant molecular information from parental cells. Tumor-derived exosomes have been widely recognized as noninvasive biomarkers for early cancer diagnosis and surveillance, but the separation of intact exosomes and detection of exosomal proteins remain challenging. Herein, we proposed a microfluidic chip for specific exosome isolation, integrated with sensitive quantification by a novel PTCDI-aptamer signal switch strategy. To enhance the capture efficiency, an alternating drop-shaped micropillar array was designed to assist the capture of tumor-derived exosomes by Tim4-modified magnetic beads (Tim4 beads) on the chip. Following capture, a chelating agent can easily elute intact exosomes which were further used for profiling exosomal surface proteins by the multiplexed fluorescence turn-on approach. Profiting from the efficient on-chip enrichment of the Tim4 beads and superior fluorescence signal transduction strategy, the detection limit of the analysis platform for HepG2 exosomes is as low as 8.69 × 103 particles/mL with a wide linear range spanning 6 orders of magnitude. Meanwhile, the proposed platform could recognize subtle changes in protein levels on the exosomal surface from various cell lines. More importantly, this strategy is successfully applied to analyze exosomes in human serum to distinguish liver cancer patients from healthy individuals. Combined analysis of different types of biomarkers on the exosomal membrane surface can greatly improve the accuracy of cancer type identification and disease monitoring. We hope that this convenient, rapid, and sensitive platform may become a powerful tool in the field of exosome analysis and early cancer screening.


Assuntos
Exossomos , Neoplasias Hepáticas , Perileno , Exossomos/metabolismo , Humanos , Imidas , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/metabolismo , Perileno/análogos & derivados
10.
Opt Lett ; 47(12): 3051-3054, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35709047

RESUMO

High-power red lasers (mainly at 639 and 670 nm) based on Pr3+:YLF crystals have been presented in many works. However, the spectral resources of Pr3+:YLF in the red region have not been fully developed to obtain lasers due to their relatively low emission cross sections and the irrepressible strong emission at ∼639 nm. In this work, we propose a scheme to further develop the spectral resources of Pr3+:YLF in the red region and improve the red laser powers based on this crystal. The laser wavelengths are obtained from 634.5 to 674.7 nm (continuous tunings are achieved at some wavebands). To the best of our knowledge, the output powers obtained at 638.7, 644.6, 670.1, and 674.7 nm (2.88 W, 1.87 W, 3.55 W, and 1.73 W, respectively) are the highest to date. Furthermore, lasing originating from the 3P2 energy level of Pr3+:YLF (∼653 nm) is realized for the first time.


Assuntos
Lasers de Estado Sólido , Luz
11.
Opt Lett ; 47(24): 6405-6408, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36538449

RESUMO

To date, lasing in the visible to near-infrared wavelengths has been studied for praseodymium-doped fluoride fibers with the upper energy level of 3P0. In this Letter, a fiber laser operating at 1015 nm has been realized for the first time, to the best of our knowledge, which confirms a new mechanism where 1D2 can be the upper energy level. A maximum output power of 241 mW, with a slope efficiency of 30%, was achieved by using a 150-cm-long active fiber pumped at a maximum pump power of 823 mW. Furthermore, the broad emission spectra of Pr3+-doped fibers in the near-infrared band have been exploited as new, to the best of our knowledge, spectral sources.

12.
Langmuir ; 38(1): 299-308, 2022 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-34936368

RESUMO

Glioblastoma multiforme (GBM) is the most aggressive tumor of the central nervous system in adults. The standard therapy of GBM fails to eradicate it due to the drug resistance of glioblastoma stem cells (GSCs) and the presence of the blood-brain-barrier (BBB). Temozolomide (TMZ) is the first-line anti-GBM drug after surgery. However, the high activity of O6-alkylguanine-DNA alkyltransferase (AGT) limits the therapeutic effect of TMZ. Herein, we reported dual-receptor-specific exosomes as vehicles loaded with TMZ and O6-benzylguanine (BG) for eradicating TMZ-resistant GBM. Exosomes pose great promise as nanocarriers due to their intrinsic low immunogenicity, strong cargo-protective capacity, ideal size range, and natural penetration ability of the blood-brain-barrier (BBB). The target ligands angiopep-2 and CD133 RNA aptamers were conjugated on exosomes via an amphiphilic molecule bridge, which was induced to express on donor cells. The resulting nanocarriers exhibited efficient uptake by U87MG and GSCs, excellent BBB penetration ability, and perfect GBM accumulation due to An2 and CD133 aptamer functionalization. Such superior properties of the two dual-receptor-specific exosomes resulted in excellent in vitro proliferation inhibition of U87MG and GSCs and extension of the median survival time of U87MG-bearing mice, without causing adverse effects. The formed exosome nanocomposites can serve as powerful nanomedicine for GBM therapy and provide a promising avenue for targeted therapy against other diseases of the central nervous system.


Assuntos
Neoplasias Encefálicas , Exossomos , Glioblastoma , Glioma , Preparações Farmacêuticas , Animais , Neoplasias Encefálicas/tratamento farmacológico , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Glioblastoma/tratamento farmacológico , Camundongos , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Analyst ; 147(14): 3209-3218, 2022 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-35708052

RESUMO

Compared with the well-studied cations, the development of methods for anion detection is relatively slow due to the anion characteristics such as a complex geometry, strong hydration and a low charge density. Herein, a colorimetric and ratiometric fluorescent anion sensing platform based on trihexyltetradecylphosphonium chloride ([THTP][Cl]) was developed for the first time. Such nanosensors exhibited a pH response of 5-7 as well as a high selectivity to perchlorate. The selectivity behavior followed the Hofmeister series in which lipophilic anions were more readily co-extracted. To deviate from the Hofmeister series, anion ionophores should be introduced for selective complexation of the target anions. As a proof of concept, the organomercury compounds ETH9033 and ETH9009 were employed as model ionophores. The obtained nitrate- and chloride-selective [THTP][Cl]-based nanosensors demonstrated prominent colorimetric and spectroscopic transformations specifically induced by the anion species. The fluorescence (I675/I600) and absorbance (A650/A500) intensities versus the logarithm values of anion concentrations proved a high selectivity towards the major anion. The excellent performance such as high selectivity, good sensitivity and fast response times enabled the accurate determination of nitrate in mineral water. More importantly, through simply altering the ionophores, a pool of [THTP][Cl]-based anion-selective nano-optodes for extended targets could be achieved. The nanosensor shows great potential for anion determination in the environmental and biomedical fields.


Assuntos
Nitratos , Compostos Organofosforados , Ânions , Cloretos/química , Ionóforos/química
14.
Clin Nephrol ; 97(6): 311-320, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35006070

RESUMO

AIM: To explore the safety, effectiveness, and dialysis adequacy of simplified regional citrate anticoagulation hemodialysis (SRCA-HD) in hemodialysis patients with high risk of bleeding. MATERIALS AND METHODS: From 64 hemodialysis patients, 400 cases of low blood flow (150 mL/min, dialysate flow 300 mL/min) SRCA-HD were retrospectively analyzed and subsequently referred to as the LBF-SRCA group. Then, a prospective cross-over study was performed in 24 hemodialysis patients with normal blood flow (200 mL/min, dialysate flow 500 mL/min) SRCA-HD, which was called the NBF-SRCA group. Citrate was pumped at the artery pipeline, and calcium-containing dialysate (A group: 1.25 mmol/L, B group: 1.5 mmol/L) was used. The differences in laboratory tests, pipeline and dialyzer clotting, adequacy of dialysis, and adverse events of the groups were compared. RESULTS: 1) In the LBF-SRCA study, the correlation between citrate dosage and serum Ca2+ level at 2 hours post-filter during dialysis was negative (r = -0.228, p < 0.05). Compared with the LBF-SRCA and NBF-SRCA-A group, the pump speed of citrate in the NBF-SRCA-B group was the highest, with 355.0 ± 19.5 mL/h, 396.3 ± 11.9 mL/h, and 407.7 ± 13.0 mL/h, respectively, p < 0.001. 2) The serum Ca2+ at 2 and 4 hours post-filter during dialysis in the NBF-SRCA-B group was closer to the physiological level and significantly higher than in the A group, with 0.80 ± 0.06 vs. 0.68 ± 0.12 mmol/L, p < 0.001; 1.03 ± 0.11 vs. 0.93 ± 0.10 mmol/L, p = 0.005, respectively. 3) Both Kt/V of the NBF-SRCA-A (1.17 ± 0.24) and B (1.22 ± 0.23) group were significantly higher than that of the LBF-SRCA group (0.94 ± 0.02), p = 0.024 and p = 0.005, respectively. 4) The efficiency of anticoagulation was higher than 95% LBF-SRCA, NBF-SRCA-A and NBF-SRCA-B groups. The total clotting in the NBF-SRCA-B group (5/24) was significantly higher than that in the A group (3/24), p = 0.005. CONCLUSION: SRCA is safe, simple, and effective in hemodialysis. The dosage of citrate can be adjusted by monitoring serum Ca2+ at 2 hours post-filter during dialysis. BFR of 200 mL/min, dialysate flow rate of 500 mL/min, and 1.5 mmol/L calcium dialysate are much safer in hemodialysis patients with a high-risk of bleeding.


Assuntos
Anticoagulantes , Citratos , Diálise Renal , Anticoagulantes/efeitos adversos , Cálcio , Citratos/efeitos adversos , Estudos Cross-Over , Soluções para Diálise , Hemorragia/induzido quimicamente , Humanos , Estudos Prospectivos , Estudos Retrospectivos
15.
Eur Respir J ; 57(3)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32972986

RESUMO

INTRODUCTION: The chronic obstructive pulmonary disease (COPD) bacteriome associates with disease severity, exacerbations and mortality. While COPD patients are susceptible to fungal sensitisation, the role of the fungal mycobiome remains uncertain. METHODS: We report the largest multicentre evaluation of the COPD airway mycobiome to date, including participants from Asia (Singapore and Malaysia) and the UK (Scotland) when stable (n=337) and during exacerbations (n=66) as well as nondiseased (healthy) controls (n=47). Longitudinal mycobiome analysis was performed during and following COPD exacerbations (n=34), and examined in terms of exacerbation frequency, 2-year mortality and occurrence of serum specific IgE (sIgE) against selected fungi. RESULTS: A distinct mycobiome profile is observed in COPD compared with controls as evidenced by increased α-diversity (Shannon index; p<0.001). Significant airway mycobiome differences, including greater interfungal interaction (by co-occurrence), characterise very frequent COPD exacerbators (three or more exacerbations per year) (permutational multivariate ANOVA; adjusted p<0.001). Longitudinal analyses during exacerbations and following treatment with antibiotics and corticosteroids did not reveal any significant change in airway mycobiome profile. Unsupervised clustering resulted in two clinically distinct COPD groups: one with increased symptoms (COPD Assessment Test score) and Saccharomyces dominance, and another with very frequent exacerbations and higher mortality characterised by Aspergillus, Curvularia and Penicillium with a concomitant increase in serum sIgE levels against the same fungi. During acute exacerbations of COPD, lower fungal diversity associates with higher 2-year mortality. CONCLUSION: The airway mycobiome in COPD is characterised by specific fungal genera associated with exacerbations and increased mortality.


Assuntos
Micobioma , Doença Pulmonar Obstrutiva Crônica , Ásia , Progressão da Doença , Humanos , Malásia , Escócia , Singapura
16.
New Phytol ; 232(3): 1286-1296, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34324717

RESUMO

Close coupling between water loss and carbon dioxide uptake requires coordination of plant hydraulics and photosynthesis. However, there is still limited information on the quantitative relationships between hydraulic and photosynthetic traits. We propose a basis for these relationships based on optimality theory, and test its predictions by analysis of measurements on 107 species from 11 sites, distributed along a nearly 3000-m elevation gradient. Hydraulic and leaf economic traits were less plastic, and more closely associated with phylogeny, than photosynthetic traits. The two sets of traits were linked by the sapwood to leaf area ratio (Huber value, vH ). The observed coordination between vH and sapwood hydraulic conductivity (KS ) and photosynthetic capacity (Vcmax ) conformed to the proposed quantitative theory. Substantial hydraulic diversity was related to the trade-off between KS and vH . Leaf drought tolerance (inferred from turgor loss point, -Ψtlp ) increased with wood density, but the trade-off between hydraulic efficiency (KS ) and -Ψtlp was weak. Plant trait effects on vH were dominated by variation in KS , while effects of environment were dominated by variation in temperature. This research unifies hydraulics, photosynthesis and the leaf economics spectrum in a common theoretical framework, and suggests a route towards the integration of photosynthesis and hydraulics in land-surface models.


Assuntos
Fotossíntese , Folhas de Planta , Árvores , Água , Madeira
17.
Opt Express ; 29(10): 15564-15575, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33985254

RESUMO

Green laser sources have become increasingly important for the application in scientific research and industry. Although several laser approaches have been investigated, the development of green lasers with the necessary efficiency and spectral characteristics required for practical deployment continues to attract immense interest. In this study, the efficient green laser operation of a Ho3+-doped fluoride fiber directly pumped by a commercial blue laser diode (LD) is experimentally investigated at various active fiber lengths. In the free-running laser, the slope efficiency was optimized up to 59.3% with 543.9 nm lasing, with respect to the launched pump power, using a 20-cm long active fiber. This is the maximum slope efficiency reported to date for a green fiber laser. A maximum output power of 376 mW at 543.5 nm was achieved by using a 17-cm long active fiber pumped at a maximum available launched pump power of 996 mW. Moreover, broadband tuning operation was demonstrated by employing a range of active fiber lengths, together with an intracavity bandpass filter. The operating wavelength was tunable from 536.3 nm to 549.3 nm. A maximum tuning power achieved was 118 mW at 543.4 nm for a 17-cm long active fiber. Moderate Ho3+-doped fiber length is shown to be effective in producing a high performance of a green fiber laser. The short-length of the active fiber considerably extends the green short wavelength operation due to limited reabsorption of the signal below 540 nm.

18.
Mol Cell Biochem ; 476(2): 1051-1061, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33170430

RESUMO

Long non-coding RNAs (lncRNAs) are known as crucial regulators in the development of OC. In the current study, we aim to explore the function and molecular mechanism of lncRNA DLEU1 in OC. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to determine the expression of DLEU1, miR-429, and TFAP2A in OC cells and tissues. The relationship among DLEU1, miR-429, and TFAP2A was tested by dual-luciferase reporter (DLR) assay. Besides, the proliferative, migratory and invasive abilities of OC cells were analyzed by MTT, wound healing, and transwell assays, respectively. Western blot was performed to determine the protein expression of TFAP2A. The expression of lncRNA DLEU1 and TFAP2A were upregulated, and miR-429 was downregulated in OC tissues. Silencing of DLEU1 inhibited the proliferation, migration, and invasion of OC cells. Bioinformation and DLR assay showed that DLEU1 acted as the sponge for miR-429. Moreover, miR-429 could directly target TFAP2A and inhibit the proliferation, migration, and invasion of OC cells. Moreover, we observed a negative correlation between miR-429 and DLEU1, and between miR-429 and TFAP2A in OC tissues. The transfection of miR-429 inhibitor or pcDNA-TFAP2A reversed the inhibitory effects of si-DLEU1 on the proliferation, migration, and invasion of OC cells. Silencing of DLEU1 inhibited the proliferation, migration, and invasion of OC cells by regulating miR-429/TFAP2A axis, indicating a potential therapeutic target for OC.


Assuntos
Carcinoma Epitelial do Ovário/prevenção & controle , Regulação Neoplásica da Expressão Gênica , Inativação Gênica , MicroRNAs/genética , Neoplasias Ovarianas/prevenção & controle , RNA Longo não Codificante/antagonistas & inibidores , Fator de Transcrição AP-2/antagonistas & inibidores , Adulto , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/metabolismo , Carcinoma Epitelial do Ovário/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Biologia Computacional/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , RNA Longo não Codificante/genética , Transdução de Sinais , Fator de Transcrição AP-2/metabolismo , Regulação para Cima
19.
Analyst ; 146(18): 5542-5549, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34515703

RESUMO

Tumor-related exosomes, which are heterogeneous membrane-enclosed nanovesicles shed from cancer cells, have been widely recognized as potential noninvasive biomarkers for early cancer diagnosis. Herein, an artificial enzyme cascade amplification strategy based on a switchable DNA tetrahedral (SDT) scaffold was proposed for quantification of breast cancer-derived exosomes. The SDT scaffold is composed of G-quadruplex mimicking DNAzyme sequences on its two single-stranded edges and glucose oxidase (GOx) on the four termini of the complementary strands. In the initial state, the SDT scaffold is blocked by the switch strand which consists of partial complementary domains with the DNA tetrahedron and a MUC1 aptamer. MCF-7 exosomes could release the quadruplex-forming sequences through the recognition of the MUC1 aptamer. The newly formed DNAzyme brings GOx into spatial proximity and induces high-efficiency enzyme cascade catalytic reactions on the SDT. Consequently, high sensitivity toward MCF-7 exosome analysis was obtained with a wide linear range of 3.8 × 106 to 1.2 × 108 particles per mL and a limit of detection of 1.51 × 105 particles per mL. In addition, such a DNAzyme reconfiguration strategy was able to distinguish MCF-7 exosomes from other breast cancer cell derived exosomes, indicating its excellent method specificity. The proposed enzyme cascade strategy not only provides a novel signal transformation and amplification nanoplatform for quantifying the specific populations of exosomes, but also can be further expanded to the analysis of multiple cancer biomarkers.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Neoplasias da Mama , DNA Catalítico , Exossomos , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , DNA Catalítico/genética , Exossomos/genética , Feminino , Humanos , Limite de Detecção
20.
Eur Respir J ; 56(2)2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32341102

RESUMO

INTRODUCTION: Allergic sensitisation to fungi such as Aspergillus are associated to poor clinical outcomes in asthma, bronchiectasis and cystic fibrosis; however, clinical relevance in COPD remains unclear. METHODS: Patients with stable COPD (n=446) and nondiseased controls (n=51) were prospectively recruited across three countries (Singapore, Malaysia and Hong Kong) and screened against a comprehensive allergen panel including house dust mites, pollens, cockroach and fungi. For the first time, using a metagenomics approach, we assessed outdoor and indoor environmental allergen exposure in COPD. We identified key fungi in outdoor air and developed specific-IgE assays against the top culturable fungi, linking sensitisation responses to COPD outcomes. Indoor air and surface allergens were prospectively evaluated by metagenomics in the homes of 11 COPD patients and linked to clinical outcome. RESULTS: High frequencies of sensitisation to a broad range of allergens occur in COPD. Fungal sensitisation associates with frequent exacerbations, and unsupervised clustering reveals a "highly sensitised fungal predominant" subgroup demonstrating significant symptomatology, frequent exacerbations and poor lung function. Outdoor and indoor environments serve as important reservoirs of fungal allergen exposure in COPD and promote a sensitisation response to outdoor air fungi. Indoor (home) environments with high fungal allergens associate with greater COPD symptoms and poorer lung function, illustrating the importance of environmental exposures on clinical outcomes in COPD. CONCLUSION: Fungal sensitisation is prevalent in COPD and associates with frequent exacerbations representing a potential treatable trait. Outdoor and indoor (home) environments represent a key source of fungal allergen exposure, amenable to intervention, in "sensitised" COPD.


Assuntos
Poluição do Ar em Ambientes Fechados , Doença Pulmonar Obstrutiva Crônica , Poluição do Ar em Ambientes Fechados/análise , Alérgenos , Fungos , Hong Kong , Humanos , Malásia/epidemiologia , Singapura
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