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1.
Small ; : e2400997, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38712477

ABSTRACT

Dielectric capacitors are widely used in advanced electrical and electronic systems due to the rapid charge/discharge rates and high power density. High comprehensive energy storage properties are the ultimate ambition in the field of application achievements. Here, the high-entropy strategy is proposed to design and fabricate single-phase homogeneous (Bi0.5Ba0.1Sr0.1Ca0.2Na0.1)(Fe0.5Ti0.3Zr0.1Nb0.1)O3 ceramic, the hierarchical heterostructure including rhombohedral-tetragonal multiphase nanoclusters and locally disordered oxygen octahedral tilt can lead to the increased dielectric relaxation, diffused phase transition, diverse local polarization configurations, grain refinement, ultrasmall polar nanoregions, large random field, delayed polarization saturation and improved breakdown field. Accordingly, a giant Wrec ≈13.3 J cm-3 and a high η ≈78% at 66.4 kV mm-1 can be simultaneously achieved in the lead-free high-entropy BiFeO3-based ceramic, showing an obvious advantage in overall energy-storage properties over BiFeO3-based lead-free ceramics. Moreover, an ultrafast discharge rate (t0.9 = 18 ns) can be achieved at room temperature, concomitant with favorable temperature stability in the range of 20-160 °C, due to the enhanced diffuse phase transition and fast polarization response. This work provides a feasible pathway to design and generate dielectric materials exhibiting high comprehensive energy-storage performance.

2.
BMC Cancer ; 24(1): 576, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38730348

ABSTRACT

OBJECTIVE: Nasopharyngeal adenoid cystic carcinoma (NACC) is a rare malignancy with special biological features. Controversies exist regarding the treatment approach and prognostic factors in the IMRT era. This study aimed to evaluate the long-term outcomes and management approaches in NACC. METHODS: Fifty patients with NACC at our institution between 2010 and 2020 were reviewed. Sixteen patients received primary radiotherapy (RT), and 34 patients underwent primary surgery. RESULTS: Between January 2010 and October 2020, a total of 50 patients with pathologically proven NACC were included in our analysis. The median follow-up time was 58.5 months (range: 6.0-151.0 months). The 5-year overall survival rate (OS) and progression-free survival rate (PFS) were 83.9% and 67.5%, respectively. The 5-year OS rates of patients whose primary treatment was surgery and RT were 90.0% and 67.3%, respectively (log-rank P = 0.028). The 5-year PFS rates of patients whose primary treatment was surgery or RT were 80.8% and 40.7%, respectively (log-rank P = 0.024). Multivariate analyses showed that nerve invasion and the pattern of primary treatment were independent factors associated with PFS. CONCLUSIONS: Due to the relative insensitivity to radiation, primary surgery seemed to provide a better chance of disease control and improved survival in NACC. Meanwhile, postoperative radiotherapy should be performed for advanced stage or residual tumours. Cranial nerve invasion and treatment pattern might be important factors affecting the prognosis of patients with NACC.


Subject(s)
Carcinoma, Adenoid Cystic , Nasopharyngeal Neoplasms , Radiotherapy, Intensity-Modulated , Humans , Carcinoma, Adenoid Cystic/radiotherapy , Carcinoma, Adenoid Cystic/mortality , Carcinoma, Adenoid Cystic/pathology , Carcinoma, Adenoid Cystic/surgery , Male , Female , Radiotherapy, Intensity-Modulated/methods , Middle Aged , Adult , Nasopharyngeal Neoplasms/radiotherapy , Nasopharyngeal Neoplasms/mortality , Nasopharyngeal Neoplasms/pathology , Aged , Retrospective Studies , Nasopharyngeal Carcinoma/radiotherapy , Nasopharyngeal Carcinoma/mortality , Nasopharyngeal Carcinoma/pathology , Young Adult , Prognosis , Survival Rate , Treatment Outcome , Follow-Up Studies , Adolescent , Progression-Free Survival
3.
BMC Womens Health ; 24(1): 307, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38783362

ABSTRACT

BACKGROUND: This study aimed to analyze the relationship between physical activity and the risk of premenstrual syndrome among college students. METHODS: Eligible studies were searched from the PubMed, Web of Science, and Embase databases. The link between physical activity and the risk of premenstrual syndrome was evaluated using odds ratio (OR) and 95% confidence interval (CI). The heterogeneity of the included studies was tested and their sources were explored by subgroup analysis. A sensitivity analysis was performed to assess the effect of a single study on the pooled results. The included studies were evaluated for publication bias. Five moderate-quality studies were included in this meta-analysis. RESULTS: Physical activity levels were negatively associated with risk of premenstrual syndrome among college students (OR [95%CI] = 1.46 [1.09, 1.96], P = .011). The pooled results were not influenced after being stratified by the study region and whether multi-factor correction was performed or not. Publication bias was not observed in the included studies. CONCLUSION: A high level of physical activity is dramatically associated with a reduced risk of premenstrual syndrome among female college students.


Subject(s)
Exercise , Premenstrual Syndrome , Students , Humans , Premenstrual Syndrome/epidemiology , Female , Students/statistics & numerical data , Exercise/physiology , Universities , Young Adult , Risk Factors , Adult
4.
Environ Sci Pollut Res Int ; 31(21): 31240-31258, 2024 May.
Article in English | MEDLINE | ID: mdl-38630395

ABSTRACT

Sub-Saharan Africa (SSA) is seeing exceptional urbanization and economic expansion rates. Therefore, the STIRPAT (Stochastic Impacts by Regression on Population, Affluence, and Technology) parameters and the spatial econometric framework are used in this work to examine the influence of economic growth and urbanization on SSA's CO2 emissions. Likewise, to determine the spatial effect and understand how factors influence the spatial dependence of carbon emissions, the study builds a spatial Durbin model (SDM). In line with the findings, the spatial correlation test revealed the spatial correlations across various countries. This indicates that the changes in sub-Saharan African country's CO2 emissions impacted nearby countries and the countries themselves. Additionally, the findings reveal that, in the SSA's countries, urbanization, economic growth, industrial structure, trade, and population, excluding energy intensity, which failed the significant test, all positively influence CO2 outflows, in line with the spatial econometric model's findings. Thus, energy intensity shares an adverse impact on carbon emissions. As an outcome, energy intensity reduces carbon dioxide emissions in nearby nations and the entire region. Thus, the study recommends that policymakers account for the effects of spatial spillover when establishing low-carbon policies, encouraging a low-carbon lifestyle, promoting environmentally friendly technologies, and improving regional collaboration.


Subject(s)
Carbon Dioxide , Economic Development , Urbanization , Carbon Dioxide/analysis , Africa South of the Sahara , Air Pollutants/analysis , Humans , Air Pollution
5.
Oncogene ; 43(21): 1594-1607, 2024 May.
Article in English | MEDLINE | ID: mdl-38565944

ABSTRACT

Prostate cancer (PCa) remains a significant cause of morbidity and mortality among men worldwide. A number of genes have been implicated in prostate tumorigenesis, but the mechanisms underlying their dysregulation are still incompletely understood. Evidence has established the competing endogenous RNA (ceRNA) theory as a novel regulatory mechanism for post-transcriptional alterations. Yet, a comprehensive characterization of ceRNA network in PCa lacks. Here we utilize stringent in-silico methods to construct a large ceRNA network across different PCa stages, and provide experimental demonstration for the competing regulation among protumorigenic SEC23A, PHTF2, and their corresponding ceRNA pairs. Using machine learning, we establish a ceRNA-based signature (ceRNA_sig) predictive of androgen receptor (AR) activity, tumor aggressiveness, and patient outcomes. Importantly, we identify miR-375 as a key node in PCa ceRNA network, which is upregulated in PCa relative to normal tissues. Forced expression of miR-375 significantly inhibits, while its inhibition promotes, aggressive behaviors of both AR+ and AR- PCa cells in vitro and in vivo. Mechanistically, we show that miR-375 predominantly targets genes possessing oncogenic roles (e.g., proliferation, DNA repair, and metastasis), and thus release targets with tumor suppressive functions. This action model well clarifies why an upregulated miRNA plays a tumor suppressive role in PCa. Together, our study provides new insights into understanding of transcriptomic aberrations during PCa evolution, and nominates miR-375 as a potential therapeutic target for combating aggressive PCa.


Subject(s)
Gene Expression Regulation, Neoplastic , Gene Regulatory Networks , MicroRNAs , Prostatic Neoplasms , MicroRNAs/genetics , Humans , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Male , Mice , Animals , Up-Regulation/genetics , Cell Line, Tumor , Receptors, Androgen/genetics , Receptors, Androgen/metabolism , Genes, Tumor Suppressor , Cell Proliferation/genetics , RNA, Competitive Endogenous
6.
J Agric Food Chem ; 72(15): 8618-8631, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38569082

ABSTRACT

Daidzein (DAN) is an isoflavone, and it is often found in its natural form in soybean and food supplements. DAN has poor bioavailability owing to its extremely low water solubility and first-pass metabolism. Herein, we hypothesized that a bioactivatable natural amino acid-bearing carbamate prodrug strategy could increase the water solubility and metabolic stability of DAN. To test our hypothesis, nine amino acid prodrugs of DAN were designed and synthesized. Compared with DAN, the optimal prodrug (daidzein-4'-O-CO-N-isoleucine, D-4'-I) demonstrated enhanced water solubility and improved phase II metabolic stability and activation to DAN in plasma. In addition, unlike the passive transport of DAN, D-4'-I maintained high permeability via organic anion-transporting polypeptide 2B1 (OATP2B1)-mediated transport. Importantly, D-4'-I increased the oral bioavailability by 15.5-fold, reduced the gender difference, and extended the linear absorption capacity in the pharmacokinetics of DAN in rats. Furthermore, D-4'-I exhibited dose-dependent protection against liver injury. Thus, the natural amino acid-bearing carbamate prodrug strategy shows potential in increasing water solubility and improving phase II metabolic stability to enhance the oral bioavailability of DAN.


Subject(s)
Isoflavones , Prodrugs , Animals , Rats , Administration, Oral , Amino Acids/chemistry , Biological Availability , Carbamates/chemistry , Prodrugs/chemistry , Solubility , Water
7.
Biochem Biophys Res Commun ; 710: 149887, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38581954

ABSTRACT

SS-31 is a mitochondria-targeting short peptide. Recent studies have indicated its hepatoprotective effects. In our study, we investigated the impact of SS-31 on LPS-induced autophagy in HepG2 cells. The results obtained from a dual-fluorescence autophagy detection system revealed that SS-31 promotes the formation of autolysosomes and autophagosomes, thereby facilitating autophagic flux to a certain degree. Additionally, both ELISA and qPCR analyses provided further evidence that SS-31 safeguards HepG2 cells against inflammatory responses triggered by LPS through ATG5-dependent autophagy. In summary, our study demonstrates that SS-31 inhibits LPS-stimulated inflammation in HepG2 cells by upregulating ATG5-dependent autophagy.


Subject(s)
Autophagy , Lipopolysaccharides , Humans , Hep G2 Cells , Lipopolysaccharides/pharmacology , Autophagosomes , Inflammation , Autophagy-Related Protein 5/genetics
8.
Sci Adv ; 10(14): eadm7098, 2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38569039

ABSTRACT

Histopathological heterogeneity is a hallmark of prostate cancer (PCa). Using spatial and parallel single-nucleus transcriptomics, we report an androgen receptor (AR)-positive but neuroendocrine-null primary PCa subtype with morphologic and molecular characteristics of small cell carcinoma. Such small cell-like PCa (SCLPC) is clinically aggressive with low AR, but high stemness and proliferation, activity. Molecular characterization prioritizes protein translation, represented by up-regulation of many ribosomal protein genes, and SP1, a transcriptional factor that drives SCLPC phenotype and overexpresses in castration-resistant PCa (CRPC), as two potential therapeutic targets in AR-indifferent CRPC. An SP1-specific inhibitor, plicamycin, effectively suppresses CRPC growth in vivo. Homoharringtonine, a Food And Drug Administration-approved translation elongation inhibitor, impedes CRPC progression in preclinical models and patients with CRPC. We construct an SCLPC-specific signature capable of stratifying patients for drug selectivity. Our studies reveal the existence of SCLPC in admixed PCa pathology, which may mediate tumor relapse, and establish SP1 and translation elongation as actionable therapeutic targets for CRPC.


Subject(s)
Prostatic Neoplasms, Castration-Resistant , Male , Humans , Prostatic Neoplasms, Castration-Resistant/drug therapy , Receptors, Androgen/genetics , Receptors, Androgen/metabolism , Neoplasm Recurrence, Local , Transcription Factors/metabolism , Protein Biosynthesis , Cell Line, Tumor , Gene Expression Regulation, Neoplastic
9.
Adv Sci (Weinh) ; : e2309303, 2024 Apr 06.
Article in English | MEDLINE | ID: mdl-38582516

ABSTRACT

The development of highly active, reusable catalysts for aqueous-phase reactions is challenging. Herein, metallic nickel is encapsulated in a nitrogen-doped carbon-silica composite (SiO2@Ni@NC) as a catalyst for the selective hydrogenation of vanillin in aqueous media. The constructed catalyst achieved 99.8% vanillin conversion and 100% 4-hydroxymethyl-2-methoxyphenol selectivity at room temperature. Based on combined scanning transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman analyses, the satisfactory catalytic performance is attributed to the composite structure consisting of an active metal, carbon, and silica. The hydrophilic silica core promoted dispersion of the catalyst in aqueous media. Moreover, the external hydrophobic NC layer has multiple functions, including preventing oxidation or leaching of the internal metal, acting as a reducing agent to reduce the internal metal, regulating the active-site microenvironment by enriching the concentrations of H2 and organic reactants, and modifying the electronic structure of the active metal via metal-support interactions. Density functional theory calculations indicated that NC facilitates vanillin adsorption and hydrogen dissociation to promote aqueous-phase hydrogenation. This study provides an efficient strategy for constructing encapsulated Ni-based amphiphilic catalysts to upgrade biomass-derived compounds.

10.
Front Plant Sci ; 15: 1362149, 2024.
Article in English | MEDLINE | ID: mdl-38516660

ABSTRACT

The improvement of nutrients in soil is essential for using deserts and decertified ecosystems and promoting sustainable agriculture. Grapevines are suitable crops for desert soils as they can adapt to harsh environments and effectively impact soil nutrients; however, the mechanisms underlying this remain unclear. This study explored the impact of the different duration(3, 6, and 10 years) of grape cultivation on soil organic carbon, physicochemical properties, enzyme activities, microbial communities, and carbon cycle pathways in both rhizosphere and bulk soils. Partial least squares path modeling was used to further reveal how these factors contributed to soil nutrient improvement. Our findings indicate that after long-term grape cultivation six years, soil organic carbon, total nitrogen, total phosphorus, microbial biomass carbon and nitrogen, and enzyme activities has significantly increased in both rhizosphere and bulk soils but microbial diversity decreased in bulk soil. According to the microbial community assembly analysis, we found that stochastic processes, particularly homogenizing dispersal, were dominant in both soils. Bacteria are more sensitive to environmental changes than fungi. In the bulk soil, long-term grape cultivation leads to a reduction in ecological niches and an increase in salinity, resulting in a decrease in soil microbial diversity. Soil enzymes play an important role in increasing soil organic matter in bulk soil by decomposing plant litters, while fungi play an important role in increasing soil organic matter in the rhizosphere, possibly by decomposing fine roots and producing mycelia. Our findings enhance understanding of the mechanisms of soil organic carbon improvement under long-term grape cultivation and suggest that grapes are suitable crops for restoring desert ecosystems.

11.
STAR Protoc ; 5(1): 102942, 2024 Mar 15.
Article in English | MEDLINE | ID: mdl-38457344

ABSTRACT

Septic cardiomyopathy is associated with high mortality in septic patients, characterized by reversible systolic and diastolic dysfunction. It is essential to monitor cardiac function and hemodynamic changes in septic animals. Here, we present a protocol to monitor cardiac function and hemodynamics in septic rodents. We describe steps for performing cecal ligation and puncture on rodents to induce sepsis, acquiring two-dimensional echocardiographic and M-mode ultrasonic images, and assessing mean arterial pressure in septic animals. For complete details on the use and execution of this protocol, please refer to Zhang et al.1.


Subject(s)
Rodentia , Sepsis , Animals , Humans , Hemodynamics , Echocardiography
12.
FASEB J ; 38(6): e23548, 2024 Mar 31.
Article in English | MEDLINE | ID: mdl-38491832

ABSTRACT

Colorectal cancer (CRC) is a multifaceted disease characterized by a complex interaction between tumor cells and the surrounding microenvironment. Within this intricate landscape, exosomes have emerged as pivotal players in the tumor-stroma crosstalk, influencing the immune microenvironment of CRC. These nano-sized vesicles, secreted by both tumoral and stromal cells, serve as molecular transporters, delivering a heterogeneous mix of biomolecules such as RNAs, proteins, and lipids. In the CRC context, exosomes exert dual roles: they promote tumor growth, metastasis, and immune escape by altering immune cell functions and activating oncogenic signaling pathways and offer potential as biomarkers for early CRC detection and treatment targets. This review delves into the multifunctional roles of exosomes in the CRC immune microenvironment, highlighting their potential implications for future therapeutic strategies and clinical outcomes.


Subject(s)
Colorectal Neoplasms , Exosomes , Humans , Exosomes/metabolism , RNA/metabolism , Stromal Cells/metabolism , Colorectal Neoplasms/pathology , Tumor Microenvironment
14.
Nutr Cancer ; 76(5): 432-441, 2024.
Article in English | MEDLINE | ID: mdl-38439655

ABSTRACT

BACKGROUND: Observational studies suggests that diets and medications affect bladder cancer (BC) development, which are subject to confounding and difficult to make causal inference. Here we aimed to investigate whether those observational associations are causal and determining the potential directions and pathways. METHODS: We used 2-sample Mendelian randomization (MR) analysis to assess associations of dietary intakes, medication uses and molecules with BC risk. Genetic summary data were derived from participants of predominantly European ancestry with rigorous instruments selection, where univariable MR, mediation MR and multivariable MR were performed. RESULTS: The results of univariable MR showed 4 dietary intakes and 4 medication uses having a protective effect on BC, while 4 circulating metabolites, 440 circulating proteins and 2 gut microbes were observed to be causally associated with BC risk. Through mediation MR, we found 572 analytes showing consistent mediating effects between dietary intakes or medication uses and BC risk. Furthermore, 9 out of 16 diet-medication pairs showed significant interactions and alterations on BC when consumed jointly. CONCLUSION: In summary, the findings obtained from the current study have important implications for informing prevention strategies that point to potential lifestyle interventions or medication prescriptions to reduce the risk of developing BC.HighlightsThe current study extends observational literature in showing the importance of diets and medications on bladder cancer prevention.The associations of diets and medications on bladder cancer prevention might be through circulating metabolites, circulating proteins and gut microbiotaOur results provide a new understanding of interactions in certain diet-medication pairs which should be taken into account by both physicians and patients during the development of a treatment strategy.


Subject(s)
Ascomycota , Urinary Bladder Neoplasms , Humans , Mendelian Randomization Analysis , Urinary Bladder Neoplasms/genetics , Urinary Bladder Neoplasms/prevention & control , Life Style , Eating
15.
iScience ; 27(4): 109356, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38510149

ABSTRACT

Familial Mediterranean fever (FMF) is a periodic fever syndrome caused by variation in MEFV. FMF is known for IL-1ß dysregulation, but the innate immune landscape of this disease has not been comprehensively described. Therefore, we studied circulating inflammatory proteins, and the function of monocytes and (albeit less extensively) neutrophils in treated FMF patients in remission. We found that monocyte IL-1ß and IL-6 production was enhanced upon stimulation, in concordance with alterations in the plasma inflammatory proteome. We did not observe changes in neutrophil functional assays. Subtle differences in chromatin accessibility and transcriptomics in our small patient cohort further argued for monocyte dysregulation. Together, these observations suggest that the MEFV-mutation-mediated primary immune dysregulation in monocytes leads to chronic inflammation that is subsequently associated with counterregulatory epigenetic/transcriptional changes reminiscent of tolerance. These data increase our understanding of the innate immune changes in FMF, aiding future management of chronic inflammation in these patients.

17.
Mol Cancer ; 23(1): 49, 2024 03 08.
Article in English | MEDLINE | ID: mdl-38459596

ABSTRACT

Circular RNAs (circRNAs) play important roles in gastric cancer progression but the regulatory role of circRNAs in controlling macrophage function remains elusive. Exosomes serve as cargo for circRNAs and play a crucial role as mediators in facilitating communication between cancer cells and the tumor microenvironment. In this study, we found that circATP8A1, a previously unreported circular RNA, is highly expressed in both gastric cancer tissues and exosomes derived from plasma. Increased circATP8A1 was associated with advanced TNM stage and worse prognosis in patients with gastric cancer. We showed that  the circATP8A1 knockdown significantly inhibited gastric cancer proliferation and invasion in vitro and in vivo. Functionally, exosome circATP8A1 induced the M2 polarization of macrophages through the STAT6 pathway instead of the STAT3 pathway. Mechanistically, circATP8A1 was shown to activate the STAT6 pathway through competitive binding to miR-1-3p, as confirmed by Fluorescence In Situ Hybridization (FISH), RNA immunoprecipitation, RNA pulldown, and Luciferase reporter assays. The reversal of circATP8A1-induced STAT6 pathway activation and macrophage polarization was observed upon blocking miR-1-3p. Macrophages treated with exosomes from gastric cancer cells overexpressing circATP8A1 were able to promote gastric cancer migration, while knockdown of circATP8A1 reversed these effects in vivo. In summary, exosome-derived circATP8A1 from gastric cancer cells induce macrophages M2 polarization via the circATP8A1/miR-1-3p/STAT6 axis, and tumor progression. Our results highlight circATP8A1 as a potential prognostic biomarker and therapeutic target in gastric cancer.


Subject(s)
Exosomes , MicroRNAs , Stomach Neoplasms , Humans , Cell Line, Tumor , Cell Proliferation , Exosomes/genetics , In Situ Hybridization, Fluorescence , Macrophages , MicroRNAs/genetics , RNA, Circular/genetics , STAT6 Transcription Factor/genetics , Stomach Neoplasms/genetics , Tumor Microenvironment
18.
Int J Med Sci ; 21(4): 674-680, 2024.
Article in English | MEDLINE | ID: mdl-38464822

ABSTRACT

Background: IgA nephropathy (IgAN) is a cause of chronic kidney disease (CKD). Tubular atrophy/interstitial fibrosis is associated with IgAN prognosis. However, simple tools for predicting pathological lesions of IgAN remain limited. Our objective was to develop a tool for evaluating tubular atrophy/interstitial fibrosis in patients with IgAN. Methods: In this cross-sectional study, 410 biopsy-verified IgAN patients were included. The factors associated with the incident interstitial fibrosis or tubular atrophy in IgAN were confirmed by using logistic regression analysis. A nomogram was developed using logistic regression coefficients to evaluate tubular atrophy or interstitial fibrosis. Receiver operating characteristic curves (ROC) and calibration curves were used to determine the discriminative ability and predictive accuracy of the nomogram. Results: In this study, the IgAN patients with tubular atrophy or interstitial fibrosis were older and had a higher percentage of males, hypertension and urinary protein excretion (UPE), with high levels of serum cystatin C, serum creatinine, high-sensitivity C-reactive protein and serum C4. The eGFRcr-cys equation calculated using serum creatinine, cystatin C and UPE were considered independent influencing factors of tubular atrophy or interstitial fibrosis in patients with IgAN. Furthermore, the nomogram demonstrated good discrimination (AUC: 0.87, 95% CI 0.81 to 0.93) and calibration in the validation cohort. Conclusion: The eGFRcr-cys and UPE are associated with tubular atrophy or interstitial fibrosis in patients with IgAN. Diagnostic nomogram can predict tubular atrophy or interstitial fibrosis in IgAN.


Subject(s)
Glomerulonephritis, IGA , Male , Humans , Glomerulonephritis, IGA/diagnosis , Glomerulonephritis, IGA/complications , Cystatin C , Nomograms , Creatinine , Cross-Sectional Studies , Fibrosis , Atrophy/complications , Retrospective Studies , Kidney/pathology
19.
Chem Sci ; 15(9): 3214-3222, 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38425513

ABSTRACT

We developed a new cysteine-specific solubilizing tag strategy via a cysteine-conjugated succinimide. This solubilizing tag remains stable under common native chemical ligation conditions and can be efficiently removed with palladium-based catalysts. Utilizing this approach, we synthesized two proteins containing notably difficult peptide segments: interleukin-2 (IL-2) and insulin. This IL-2 chemical synthesis represents the simplest and most efficient approach to date, which is enabled by the cysteine-specific solubilizing tag to synthesize and ligate long peptide segments. Additionally, we synthesized a T8P insulin variant, previously identified in an infant with neonatal diabetes. We show that T8P insulin exhibits reduced bioactivity (a 30-fold decrease compared to standard insulin), potentially contributing to the onset of diabetes in these patients. In summary, our work provides an efficient tool to synthesize challenging proteins and opens new avenues for exploring research directions in understanding their biological functions.

20.
Micromachines (Basel) ; 15(2)2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38398956

ABSTRACT

We have developed a manufacturing process for micromirrors based on microelectromechanical systems (MEMS) technology. The process involves designing an electrostatic vertically comb-driven actuator and utilizing a self-alignment process to produce a height difference between the movable comb structure and the fixed comb structure of the micromirror. To improve the stability of the micromirror, we propose four instability models in micromirror operation with the quasi-static driving principle and structure of the micromirror considered, which can provide a basic guarantee for the performance of vertical comb actuators. This analysis pinpoints factors leading to instability, including the left and right gap of the movable comb, the torsion beams of the micromirror, and the comb-to-beams distance. Ultimately, the voltages at which device failure occurs can be determined. We successfully fabricated a one-dimensional micromirror featuring a 0.8 mm mirror diameter and a 30 µm device layer thickness. The height difference between the movable and fixed comb structures was 10 µm. The micromirror was able to achieve a static mechanical angle of 2.25° with 60 V@DC. Stable operation was observed at voltages below 60 V, in close agreement with the theoretical calculations and simulations. At the driving voltage of 80 V, we observed the longitudinal displacement movement of the comb fingers. Furthermore, at a voltage of 129 V, comb adhesion occurred, resulting in device failure. This failure voltage corresponds to the lateral torsional failure voltage.

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