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1.
Neurosci Bull ; 2024 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-39312108

RESUMEN

Stroke, a major cerebrovascular disease, has high morbidity and mortality. Effective methods to reduce the risk and improve the prognosis are lacking. Currently, uric acid (UA) is associated with the pathological mechanism, prognosis, and therapy of stroke. UA plays pro/anti-oxidative and pro-inflammatory roles in vivo. The specific role of UA in stroke, which may have both neuroprotective and damaging effects, remains unclear. There is a U-shaped association between serum uric acid (SUA) levels and ischemic stroke (IS). UA therapy provides neuroprotection during reperfusion therapy for acute ischemic stroke (AIS). Urate-lowering therapy (ULT) plays a protective role in IS with hyperuricemia or gout. SUA levels are associated with the cerebrovascular injury mechanism, risk, and outcomes of hemorrhagic stroke. In this review, we summarize the current research on the role of UA in stroke, providing potential targets for its prediction and treatment.

2.
Ital J Pediatr ; 50(1): 178, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39285390

RESUMEN

BACKGROUND: To evaluate the impact of implementation of 2019 European respiratory distress syndrome (RDS) guidelines on the incidence of bronchopulmonary dysplasia (BPD). METHOD: We retrospectively collected the clinical data of very preterm infants (VPIs) born before 32 gestational weeks from January 1st 2018 to December 31st 2021. VPIs were divided into group A and group B according to their birth date which was before or at/after January 1st 2020, when the 2019 European RDS guidelines were introduced. BPD is considered as primary outcome. We statistically analyzed all the data, and we compared the general characteristics, ventilation support, medication, nutrition and the outcomes between the two groups. RESULTS: A total of 593 VPIs were enrolled, including 380 cases in group A and 213 cases in group B. There were no statistic differences regarding to gender ratio, gestational age, birth weight and delivery mode between the two groups. Compared with group A, group B showed higher rate of antenatal corticosteroid therapy (75.1% vs. 65.5%). The improvement of ventilation management in these latter patients included lower rate of invasive ventilation (40.4% vs. 50.0%), higher rate of volume guarantee (69.8% vs. 15.3%), higher positive end expiratory pressure (PEEP) [6 (5, 6) vs. 5 (5, 5) cmH2O] and higher rate of synchronized nasal intermittent positive pressure ventilation (sNIPPV) (36.2% vs. 5.6%). Compared with group A, group B received higher initial dose of pulmonary surfactant [200 (160, 200) vs. 170 (130, 200) mg/Kg], shorter antibiotic exposure time [13 (7, 23) vs. 17 (9, 33) days], more breast milk (86.4% vs. 70.3%) and earlier medication for hemodynamically significant patent ductus arteriosus (hsPDA) treatment [3 (3, 4) vs. 8 (4, 11) days] (p < 0.05). As the primary outcome, the incidence of BPD was significantly decreased (16.9% vs. 24.2%) (p < 0.05), along with lower extrauterine growth retardation (EUGR) rate (39.0% vs. 59.7%), while there were no statistic differences regarding to other secondary outcomes, including mortality, intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), retinopathy of preterm (ROP) and necrotizing enterocolitis (NEC). However, in the subgroups of infants less than 28 gestational weeks or infants less than 1,000 g, the incidence of BPD was not significantly decreased (p > 0.05). CONCLUSIONS: After implementation of 2019 European RDS guidelines, the overall incidence of BPD was significantly decreased in VPIs. Continuous quality improvement is still needed in order to decrease the incidence of BPD in smaller infants who are less than 28 gestational weeks or less than 1,000 g.


Asunto(s)
Displasia Broncopulmonar , Síndrome de Dificultad Respiratoria del Recién Nacido , Humanos , Displasia Broncopulmonar/epidemiología , Displasia Broncopulmonar/terapia , Recién Nacido , Femenino , Estudios Retrospectivos , Masculino , Síndrome de Dificultad Respiratoria del Recién Nacido/terapia , Guías de Práctica Clínica como Asunto , Incidencia , Respiración Artificial , Recien Nacido Prematuro , Europa (Continente) , Recien Nacido Extremadamente Prematuro
3.
Heliyon ; 10(17): e37119, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-39286084

RESUMEN

A nanocrystalline alloy, with an iron-based composition (Fe58.5Si16.7B6.5Nb5.1Cu13.2) and a Curie temperature of 570 °C, was investigated for its effectiveness as magnetic shielding films in an induction heating system. The primary focus of the research was to evaluate the shielding performance of the 3-turned (9-layered) shielding films with dimensions of 135 mm × 17 mm × 0.15 mm. Upon winding, these films formed a cylindrical structure that enveloped the coil, with a diameter of 13.9 mm and a height of 17 mm. The results showed that increasing the degree of fragmentation within the nanocrystalline shielding films significantly reduced the magnetic permeability by decreasing the real component from 11,500 to 400 and the imaginary part from 2800 to 20. However, a lower degree of fragmentation led to a 10 % increase in the resistance (Rs) of the heating module, although this effect was less pronounced as the relative permeability continued to increase. Furthermore, observations on preheating time to a set temperature of 400 °C and total energy consumption over a duration of 250s revealed an initial downward trend, followed by a rapid increase that even exceeded the initial values as the magnetic permeability of the nanocrystalline shielding films augmented. Notably, the study emphasized that nanocrystalline shielding films with a relative permeability value of 1000 demonstrated exceptional magnetic shielding performance, resulting in a 12.5 % reduction in preheat time and 7 % less energy consumption during preheating. In addition to empirical findings, the study developed a theoretical model elucidating the shielding mechanism inherent in induction heating systems. This model serves as a robust framework for the application of nanocrystalline shielding materials in such systems, laying the groundwork for enhanced magnetic shielding capabilities in future applications.

4.
J Neuroinflammation ; 21(1): 237, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39334416

RESUMEN

BACKGROUND: Early severe cerebral edema and chronic hydrocephalus are the primary cause of poor prognosis in patients with subarachnoid hemorrhage (SAH). This study investigated the role of cerebrospinal fluid (CSF) inflammatory cytokines and coagulation factors in the development of severe cerebral edema and chronic hydrocephalus in patients with SAH. METHODS: Patients with SAH enrolled in this study were categorized into mild and severe cerebral edema groups based on the Subarachnoid Hemorrhage Early Brain Edema Score at admission. During long-term follow-up, patients were further classified into hydrocephalus and non-hydrocephalus groups. CSF samples were collected within 48 h post-SAH, and levels of inflammatory cytokines and coagulation factors were measured. Univariate and multivariate logistic regression analyses were performed to identify independent factors associated with severe cerebral edema and chronic hydrocephalus. The correlation between inflammatory cytokines and coagulation factors was further investigated and validated in a mouse model of SAH. RESULTS: Seventy-two patients were enrolled in the study. Factors from the extrinsic coagulation pathway and inflammatory cytokines were associated with both severe cerebral edema and chronic hydrocephalus. Coagulation products thrombin-antithrombin complexes (TAT) and fibrin, as well as inflammatory cytokines IL-1ß, IL-2, IL-5, IL-7, and IL-4, were independently associated with severe cerebral edema. Additionally, Factor VII, fibrin, IL-2, IL-5, IL-12, TNF-α, and CCL-4 were independently associated with chronic hydrocephalus. A positive correlation between extrinsic coagulation factors and inflammatory cytokines was observed. In the SAH mouse model, tissue plasminogen activator was shown to alleviate neuroinflammation and cerebral edema, potentially by restoring glymphatic-meningeal lymphatic function. CONCLUSIONS: Elevated levels of inflammatory cytokines and extrinsic coagulation pathway factors in the CSF are associated with the development of early severe cerebral edema and chronic hydrocephalus following SAH. These factors are interrelated and may contribute to post-SAH glymphatic-meningeal lymphatic dysfunction.


Asunto(s)
Biomarcadores , Edema Encefálico , Citocinas , Hidrocefalia , Hemorragia Subaracnoidea , Humanos , Hidrocefalia/líquido cefalorraquídeo , Hidrocefalia/etiología , Hemorragia Subaracnoidea/líquido cefalorraquídeo , Hemorragia Subaracnoidea/complicaciones , Masculino , Femenino , Edema Encefálico/líquido cefalorraquídeo , Edema Encefálico/etiología , Persona de Mediana Edad , Estudios Prospectivos , Citocinas/líquido cefalorraquídeo , Citocinas/sangre , Animales , Anciano , Ratones , Biomarcadores/líquido cefalorraquídeo , Biomarcadores/sangre , Enfermedades Neuroinflamatorias/líquido cefalorraquídeo , Enfermedades Neuroinflamatorias/etiología , Adulto , Enfermedad Crónica , Ratones Endogámicos C57BL , Coagulación Sanguínea/fisiología
5.
PeerJ ; 12: e18107, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39346046

RESUMEN

Background: We analyzed cervical sagittal parameters and muscular function in different cervical kyphosis types. Methods: This cross-sectional study enrolled subjects with cervical spine lordosis (cervical curvature < -4°) or degenerative cervical kyphosis (cervical curvature > 4°), including C-, S-, and R-type kyphosis. We recorded patients' general information (gender, age, body mass index), visual analog scale (VAS) scores, and the Neck Disability Index (NDI). Cervical sagittal parameters including C2-C7 Cobb angle (Cobb), T1 slope (T1S), C2-C7 sagittal vertical axis (SVA), spino-cranial angle (SCA), range of motion (ROM), and muscular function (flexion-relaxation ratio (FRR) and co-contraction ratio (CCR) of neck/shoulder muscles on surface electromyography). Differences in cervical sagittal parameters and muscular function in subjects with different cervical spine alignments, and correlations between VAS scores, NDI, cervical sagittal parameters, and muscular function indices were statistically analyzed. Results: The FRR of the splenius capitis (SPL), upper trapezius (UTr), and sternocleidomastoid (SCM) were higher in subjects with cervical lordosis than in subjects with cervical kyphosis. FRRSPL was higher in subjects with C-type kyphosis than in subjects with R- and S-type kyphosis (P < 0.05), and was correlated with VAS scores, Cobb angle, T1S, and SVA. FRRUTr was correlated with NDI, SCA, T1S, and SVA. FRRSCM was correlated with VAS scores and Cobb angle. CCR was correlated with SCA and SVA. Conclusion: Cervical sagittal parameters differed among different cervical kyphosis types. FRRs and CCRs were significantly worse in R-type kyphosis than other kyphosis types. Cervical muscular functions were correlated with cervical sagittal parameters and morphological alignment.


Asunto(s)
Vértebras Cervicales , Electromiografía , Cifosis , Lordosis , Músculos del Cuello , Rango del Movimiento Articular , Humanos , Estudios Transversales , Masculino , Femenino , Electromiografía/métodos , Vértebras Cervicales/fisiopatología , Vértebras Cervicales/diagnóstico por imagen , Persona de Mediana Edad , Cifosis/fisiopatología , Cifosis/diagnóstico por imagen , Rango del Movimiento Articular/fisiología , Lordosis/fisiopatología , Lordosis/diagnóstico por imagen , Músculos del Cuello/fisiopatología , Músculos del Cuello/diagnóstico por imagen , Adulto , Anciano
6.
Int Orthop ; 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39269485

RESUMEN

PURPOSE: To investigate whether congenital cervical spinal stenosis (CCSS) affects the outcome of three-level anterior cervical discectomy and fusion (ACDF) in patients with cervical spondylotic myelopathy (CSM). METHODS: One hundred seventeen patients with CSM who underwent three-level ACDF between January 2019 and January 2023 were retrospectively examined. Patients were grouped according to presence of CCSS, which was defined as Pavlov ratio ≤ 0.75. The CCSS and no CCSS groups comprised 68 (58.1%) and 49 (41.9%) patients, respectively. RESULTS: The Japanese Orthopaedic Association (JOA) score did not significantly differ between the two groups at any postoperative time point (p > 0.05). The JOA improvement rate was lower in the CCSS group 1 month after surgery (41.7% vs. 45.5%, p < 0.05), but showed no difference at any follow-up time point after one month. Multivariate logistic regression identified preoperative age (OR = 10.639), JOA score (OR = 0.370), increased signal intensity (ISI) in the spinal cord on T2-weighted MRI (T2-WI) (Grade 1: OR = 6.135; Grade 2: OR = 29.892), and degree of spinal cord compression (30-60%: OR = 17.919; ≥60%: OR = 46.624) as independent predictors of a poor one year outcome (JOA recovery rate < 50%). CONCLUSION: Although early JOA improvement is slower in the CCSS group, it does not affect the final neurological improvement at 1 year. Therefore, CCSS should not be considered a contraindication for three-level ACDF in patients with CSM. The main factors influencing one year outcome were preoperative age, JOA score, ISI grade, and degree of spinal cord compression.

7.
World Neurosurg ; 191: 172-185, 2024 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-39182836

RESUMEN

This review was performed to analyze the research on cervical spondylotic myelopathy published during the past 25 years, summarize the developments in existing research, and predict future hotspots in the field. The goal is to provide a comprehensive overview and exploration of developments in this research area. A bibliometric analysis was performed using CiteSpace and VOSviewer to quantitatively and visually analyze relevant literature from Web of Science between 1998 and 2023. Co-occurrence analysis and co-citation analysis were conducted to evaluate papers, authors, journals, countries, and keywords. In total, 1886 papers were included. The overall publication output in this field increased throughout the review period. Stable author collaboration groups were formed, with the most influential author being Fehlings M.G. Japan and the United States contributed the highest number of publications. The predicted future research hotspots include risk factor analysis, outcome prediction, and machine learning. This study provides both an overview of the research trajectory in the field of cervical spondylotic myelopathy for scholars interested in this area, as well as offering insights and references for future research directions in the field.

8.
Exploration (Beijing) ; 4(4): 20230008, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39175889

RESUMEN

Cornea is the major barrier to drug delivery to the eye, which results in low bioavailability and poor efficacy of topical eye treatment. In this work, we first select cornea-binding aptamers using tissue-SELEX on pig cornea. The top two abundant aptamers, Cornea-S1 and Cornea-S2, could bind to pig cornea, and their K d values to human corneal epithelial cells (HCECs) were 361 and 174 nм, respectively. Aptamer-functionalized liposomes loaded with cyclosporine A (CsA) were developed as a treatment for dry eye diseases. The K d of Cornea-S1- or Cornea-S2-functionalized liposomes reduces to 1.2 and 15.1 nм, respectively, due to polyvalent binding. In HCECs, Cornea-S1 or Cornea-S2 enhanced liposome uptake within 15 min and extended retention to 24 h. Aptamer CsA liposomes achieved similar anti-inflammatory and tight junction modulation effects with ten times less CsA than a free drug. In a rabbit dry eye disease model, Cornea-S1 CsA liposomes demonstrated equivalence in sustaining corneal integrity and tear break-up time when compared to commercial CsA eye drops while utilizing a lower dosage of CsA. The aptamers obtained from cornea-SELEX can serve as a general ligand for ocular drug delivery, suggesting a promising avenue for the treatment of various eye diseases and even other diseases.

9.
Front Pediatr ; 12: 1295868, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39108691

RESUMEN

Objective: This study aims to investigate the effects of hyperoxia exposure on TGF-ß1-induced endothelial-mesenchymal transition (EndoMT) and regulatory T cell (Treg)-mediated immunomodulation in human pulmonary microvascular endothelial cells (HPMECs), which could provide a theoretical basis for further studies of the pathogenesis of bronchopulmonary dysplasia (BPD). Methods: A BPD cell model was established by exposing HPMECs to hyperoxia. Flow cytometry was used to isolate CD4 + CD3 + CD25 + CD127- Tregs from the peripheral blood samples of preterm infants. HPMECs were divided into four groups based on whether they were exposed to hyperoxia and/or co-cultured with Tregs. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) were used to test the expression levels of TGF-ß1, α-SMA, Foxp3, IL-10, and reactive oxygen species (ROS). Results: The results showed that the expression levels of TGF-ß1 and α-SMA in HPMECs increased at 24 h, 48 h, and 72 h of hyperoxia exposure. In the co-culture group of HPMECs and Tregs, Foxp3 and IL-10 expressions decreased at 48 h and 72 h of hyperoxia exposure. ROS expression increased in the hyperoxia group of HPMECs at 24 h, 48 h, and 72 h of hyperoxia exposure, which were higher than those in the hyperoxia group of HPMECs and Tregs. Conclusion: These findings suggest that hyperoxia exposure promotes EndoMT in HMPECs and inhibits the immunosuppressive effect of Tregs. Despite this, Tregs still seem could protect HPMECs from oxidative stress injury.

10.
J Food Sci ; 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39138635

RESUMEN

Previous systematic evaluations and meta-analyses of the relationship between cruciferous vegetable (CV) intake and cancer risk have yielded inconsistent results. Herein, we summarize and evaluate the existing data and examine the relationship between CV intake and cancer risk. We searched four databases for cancer risk as a key outcome indicator. AMSTAR-2 was used to evaluate the methodological quality of the included systematic reviews, PRISMA 2020 was used to evaluate the report quality, and corrected coverage area analysis was used to evaluate the duplication rate of the original documents. Overall, 22 meta-analyses involving 175 independent cancer studies were included. Evidence on lung, gastric, prostate, breast, endometrial, and ovarian cancer, as well as renal cell carcinoma, suggests a potential association between cancer and CV intake, which influences the risk of various cancers. Future research should focus on improving methods and techniques, controlling influencing factors, elucidating underlying mechanisms, and improving evidence quality to demonstrate the association between CV intake and cancer. The potential role of dietary CVs in cancer control has implications for public health policies.

11.
Materials (Basel) ; 17(15)2024 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-39124375

RESUMEN

Chromium-plated diamond/copper composite materials, with Cr layer thicknesses of 150 nm and 200 nm, were synthesized using a vacuum hot-press sintering process. Comparative analysis revealed that the thermal conductivity of the composite material with a Cr layer thickness of 150 nm increased by 266%, while that with a Cr layer thickness of 200 nm increased by 242%, relative to the diamond/copper composite materials without Cr plating. This indicates that the introduction of the Cr layer significantly enhanced the thermal conductivity of the composite material. The thermal properties of the composite material initially increased and subsequently decreased with rising sintering temperature. At a sintering temperature of 1050 °C and a diamond particle size of 210 µm, the thermal conductivity of the chromium-plated diamond/copper composite material reached a maximum value of 593.67 W∙m-1∙K-1. This high thermal conductivity is attributed to the formation of chromium carbide at the interface. Additionally, the surface of the diamond particles in contact with the carbide layer exhibited a continuous serrated morphology due to the interface reaction. This "pinning effect" at the interface strengthened the bonding between the diamond particles and the copper matrix, thereby enhancing the overall thermal conductivity of the composite material.

12.
Pest Manag Sci ; 2024 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-39003636

RESUMEN

BACKGROUND: The natural product paeonol is a rich and sustainable natural bioresource, and its derivatives have various unique biological efficacy. As is well known, Schiff bases are a class of organic compounds with a wide range of biological activities, including anti-fungal, insecticidal, anti-viral, and nematicidal. RESULTS: To discover biorational natural product-based pesticides, nine intermediates (2-10), 12 sulfonylhydrazones (11a-11c, 12a-12c, 13a-13c, and 14a-14c) and 20 benzylidene hydrazones (18a-18r, 19a, and 20a) were synthesized by structural modification of paeonol, and their structures were characterized by proton nuclear magnetic resonance (1H NMR), carbon-13 (13C) NMR, and high-resolution mass spectrometry (HRMS). The stereochemical configurations of compounds 14a, 18d, and 18r were unambiguously confirmed by single-crystal X-ray diffraction. Furthermore, bioactivities of these compounds as anti-oomycete, anti-fungal, and nematicidal agents against three serious agricultural pests, Phytophthora capsici, Fusarium graminearum, and Heterodera glycines were evaluated. Among all tested compounds: (i) compound 7 exhibited promising anti-oomycete against Phytophthora capsici, with a half maximal effective concentration (EC50) value of 15.81 mg L-1; (ii) compounds 2, 7, 10, and 19a displayed promising anti-fungal against F. graminearum, with EC50 values of 12.22, 14.72, 23.39, and 33.10 mg L-1, respectively; (iii) ten compounds (12a-12c, 14c, 18g-18j, 18m, and 19a) showed significant nematicidal activity against H. glycines, with median lethal concentration (LC50) values all less than 30.00 mg L-1. Especially for compound 18g, its LC50 value is the smallest, at 12.65 mg L-1. CONCLUSION: The research results indicate that introducing nitro groups at the C5 position of paeonol, or introducing halogens at both C5 and C3 positions, can significantly enhance its biological activity against Phytophthora capsici, F. graminearum, and H. glycines. © 2024 Society of Chemical Industry.

13.
Int J Biol Macromol ; 275(Pt 1): 133643, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38964680

RESUMEN

In this study, the effects of different ultrasonic treatment intensities (57, 170, and 283 W/cm2) on the chemical composition, molecular chain characteristics, crystal structure, micromorphology, interfacial adsorption behavior and emulsifying properties of sugar beet pectin (SBP) were investigated. Ultrasonic treatment did not change the types of SBP monosaccharides, but it had impacts on their various monosaccharide contents. Moreover, the feruloylated, acetyl, and methoxy groups of SBP also undergo varying degrees of changes. The increase in ultrasonic treatment intensity led to transition in the molecular chain conformation of SBP from rigid semi-flexible chains to flexible chains, accompanied by modification in its crystal structure. Microstructural analysis of SBP confirmed the significant change in molecular chain conformation. Modified SBP could form an elastic interfacial film with higher deformation resistance on the oil-water interface. The SBP sample modified with 170 W/cm2 exhibited better emulsifying properties owing to its better interfacial adsorption behavior. Moreover, the emulsions prepared with modified SBP exhibited better stability capability under different environmental stresses (pH value, salt ion concentration, heating temperature and freeze-thaw treatment). The results revealed that the ultrasonic technology is useful to improve the emulsifying properties of SBP.


Asunto(s)
Beta vulgaris , Pectinas , Beta vulgaris/química , Pectinas/química , Emulsiones/química , Ondas Ultrasónicas , Adsorción , Conformación Molecular , Concentración de Iones de Hidrógeno
14.
J Asian Nat Prod Res ; 26(10): 1166-1174, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38859556

RESUMEN

Twenty 3-acyloxymaltol/ethyl maltol derivatives (7a-j and 8a-j) were synthesized and evaluated in vitro for their anti-oomycete activity against Phytophthora capsici, respectively. Among all of twenty derivatives, more than half of the compounds 7f, 7h, 8a-h and 8j had anti-oomycete activity higher than the positive control zoxamide (EC50 = 22.23 mg/L), and the EC50 values of 18.66, 20.32, 12.80, 16.18, 10.59, 14.98, 16.80, 10.36, 15.32, 12.64, and 13.59 mg/L, respectively. Especially, compounds 8c and 8f exhibited the best anti-oomycete activity against P. capsici with EC50 values of 10.59 and 10.36 mg/L, respectively. Overall, hydroxyl group of maltol/ethyl maltol is important active modification site.


Asunto(s)
Phytophthora , Estructura Molecular , Phytophthora/efectos de los fármacos , Pironas/farmacología , Pironas/química , Pironas/síntesis química , Relación Estructura-Actividad , Diseño de Fármacos
16.
Chem Commun (Camb) ; 60(49): 6280-6283, 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38809225

RESUMEN

We serendipitously discovered Zn2+-binding DNA aptamers when selecting insulin aptamers. The Zn-1 aptamer binds to Zn2+ with a dissociation constant (Kd) of ∼1 µM, and has 450-fold higher selectivity for Zn2+ over Cd2+. A strand-displacement based fluorescent sensor achieved a limit of detection of 0.2 µM Zn2+.


Asunto(s)
Aptámeros de Nucleótidos , Insulina , Zinc , Aptámeros de Nucleótidos/química , Zinc/química , Insulina/química , Insulina/análisis , Colorantes Fluorescentes/química , Técnicas Biosensibles , Humanos , Límite de Detección
17.
Materials (Basel) ; 17(8)2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38673197

RESUMEN

In order to enhance the quality of diamond composite materials, this work employs a Cu-Co-Fe and Ni-Cr-Cu pre-alloyed powder mixture as a transition layer, and utilizes laser-welding technology for saw blade fabrication. By adjusting the laser-welding process parameters, including welding speed and welding power, well-formed welded joints were achieved, and the microstructure and mechanical properties of the welded joints were investigated. The results demonstrate that the best welding performance was achieved at a laser power of 1600 W and a welding speed of 1400 mm/min, with a remarkable tooth engagement strength of up to 819 MPa. The fusion zone can be divided into rich Cu phase and rich Fe phase regions, characterized by coarse grains without apparent preferred orientation. The microstructure of the heat-affected zone primarily consists of high-hardness brittle quenched needle-like martensite, exhibiting a sharp increase in microhardness up to 550 HV. Fracture occurred at the boundary between the fusion zone and the heat-affected zone of the base material, where stress concentration was observed. By adjusting the welding parameters and transition layer materials, the mechanical properties of the joints were improved, thereby achieving a reliable connection between diamond composite materials and the metal substrate.

18.
Langmuir ; 40(16): 8730-8737, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38616350

RESUMEN

An elevated level of blood uric acid (UA) can cause the formation of kidney stones, gout, and other diseases. We recently isolated a few DNA aptamers that can selectively bind to UA. In this work, we investigated the adsorption of a UA aptamer and random sequence DNA onto sodium urate crystals. Both DNA strands adsorbed similarly to urate crystals. In addition, both the UA aptamer and random DNA can inhibit the growth of urate crystals, suggesting a nonspecific adsorption mechanism rather than specific aptamer binding. In the presence of 500 nM DNA, the growth of needle-like sodium urate crystals was inhibited, and the crystals appeared granular after 6 h. To understand the mechanism of DNA adsorption, a few chemicals were added to desorb DNA. DNA bases contributed more to the adsorption than the phosphate backbone. Surfactants induced significant DNA desorption. Finally, DNA could also be adsorbed onto real UA kidney stones. This study provides essential insights into the interactions between DNA oligonucleotides and urate crystals, including the inhibition of growth and interface effects of DNA on sodium urate crystals.

19.
Chem Biodivers ; 21(7): e202400929, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38661022

RESUMEN

In order to explore novel natural product-based insecticidal agent, two important intermediates (2 and 3) and 4-acyloxy-2'-bromo-6'-chloropodophyllotoxin derivatives (4 a-f and 5 a-f) were designed and prepared, and their structures were confirmed by 1H-NMR, 13C NMR, HRMS, ESI-MS, optical rotation and melting point (mp). The stereochemical configuration of compound 4 b was unambiguously confirmed by single-crystal X-ray diffraction. Moreover, we evaluated the insecticidal activity of target compounds 4 a-f and 5 a-f against a serious agricultural pest of Mythimna separata by using the leaf-dipping method. Among all tested compounds, compounds 4 d, 5 d and 5 f exhibited stronger insecticidal activity with a final mortality rate exceeding 60 %. Especially compound 5 d exhibited the best insecticidal activity, with a final mortality rate of 74.1 %. It has been proven that introducing bromine or chlorine atoms at the C-2', C-2' and C-6' positions of the E ring of podophyllotoxin can produce more potent compounds. In addition, the configuration of the C-4 position is important for insecticidal activity, and 4ß-configuration is optimal. This will pave the way for further design, structural modification, and development of derivatives of podophyllotoxin as insecticidal agents.


Asunto(s)
Insecticidas , Mariposas Nocturnas , Podofilotoxina , Insecticidas/síntesis química , Insecticidas/farmacología , Insecticidas/química , Animales , Podofilotoxina/farmacología , Podofilotoxina/química , Podofilotoxina/síntesis química , Podofilotoxina/análogos & derivados , Mariposas Nocturnas/efectos de los fármacos , Relación Estructura-Actividad , Estructura Molecular , Cristalografía por Rayos X , Conformación Molecular
20.
Food Chem ; 447: 139008, 2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-38513488

RESUMEN

We hypothesized that the addition of milk fat globule membranes (MFGMs) to infant formula would improve its lipolysis, making it more similar to human milk (HM) and superior to commercial infant formula (CIF) in fat digestion. Therefore, we prepared two model infant formulas (MIFs) by adding MFGMs to dairy ingredients in different ways and compared their fat digestion behavior with those of HM and CIF. MFGMs were added alone (MIF1) and with other milk-based materials (MIF2) before homogenization. The addition of MFGMs reduced the flocculation of lipids and proteins in the gastric phase and promoted lipolysis in the intestine phase. The amount of free fatty acids released followed the order of HM > MIF1 > CIF ≥ MIF2. After digestion, the number of different glyceride species between each sample and HM reached 64 (MIF1), 73 (MIF2), 67 (CIF1), and 72 (CIF2). In conclusion, the fat digestion of MIF1 had the highest similarity with HM.


Asunto(s)
Digestión , Glicoproteínas , Gotas Lipídicas , Lipidómica , Lactante , Humanos , Glucolípidos , Leche Humana , Fórmulas Infantiles
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