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1.
Front Med (Lausanne) ; 11: 1395790, 2024.
Article in English | MEDLINE | ID: mdl-38818392

ABSTRACT

Background: Recent studies have indicated an association between sedentary behavior (SB), particularly patterns of SB, and bone health. However, it remains uncertain how different patterns of SB in overweight/obesity older women impact their bone health. This study aimed to investigate the association between objectively measured SB patterns and bone health in Chinese community-dwelling overweight/obesity older women. Methods: Cross-sectional data were obtained from a baseline survey of Physical Activity and Health in Older Women Study. Quantitative ultrasound was used to measure speed of sound (SOS), broadband ultrasound attenuation (BUA), bone quality index (BQI) and T value to evaluate bone health. SB patterns were measured using triaxial accelerometers, including sedentary time in SB bouts of ≥ 10, 30, and 60 min, number of SB bouts ≥ 10, 30, and 60 min. Multiple linear regression was used to examine the associations of different SB patterns with bone health. Results: After adjusting for confounders, sedentary time in SB bouts ≥ 60 min, number of SB bouts ≥ 60 min were significantly associated with bone health, with a lower SOS [ß = -2.75, 95% confidence interval (CI): -4.96 to -0.53, P = 0.015], BUA (ß = -1.20, 95% CI: -2.14 to -0.26, P = 0.013), BQI (ß = -1.56, 95% CI: -2.63 to -0.49, P = 0.004), T value (ß = -0.08, 95% CI: -0.14 to -0.03, P = 0.004) per 60 min increase of sedentary time in SB bouts ≥ 60 min, and a lower SOS (ß = -3.97, 95% CI: -7.54 to -0.40, P = 0.029), BUA (ß = -1.80, 95% CI: -3.44 to -0.16, P = 0.031), BQI (ß = -2.28, 95% CI: -4.08 to -0.47, P = 0.014) and T value (ß = -0.12, 95% CI: -0.22 to -0.03, P = 0.013) per bout increase of SB bouts ≥ 60 min, respectively. Conclusion: Limiting the duration of prolonged sedentary bouts and minimizing the occurrence of number of SB bouts ≥ 60 min could be essential in bone health management, especially for those older people who are overweight/obesity.

2.
Nanomaterials (Basel) ; 14(9)2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38727341

ABSTRACT

The rough morphology at the growth surface results in the non-uniform distribution of indium composition, intentionally or unintentionally doped impurity, and thus impacts the performance of GaN-based optoelectronic and vertical power electronic devices. We observed the morphologies of unintentionally doped GaN homo-epitaxially grown via MOCVD and identified the relations between rough surfaces and the miscut angle and direction of the substrate. The growth kinetics under the effect of the Ehrlich-Schwoebel barrier were studied, and it was found that asymmetric step motions in samples with a large miscut angle or those grown at high temperature were the causes of step-bunching. Meandering steps were believed to be caused by surface free energy minimization for steps with wide terraces or deviating from the [11¯00] m-direction.

3.
J Ovarian Res ; 17(1): 113, 2024 May 25.
Article in English | MEDLINE | ID: mdl-38796525

ABSTRACT

Ovarian cancer accounts for more deaths than any other female reproductive tract cancer. The major reasons for the high mortality rates include delayed diagnoses and drug resistance. Hence, improved diagnostic and therapeutic options for ovarian cancer are a pressing need. Extracellular vesicles (EVs), that include exosomes provide hope in both diagnostic and therapeutic aspects. They are natural lipid nanovesicles secreted by all cell types and carry molecules that reflect the status of the parent cell. This facilitates their potential use as biomarkers for an early diagnosis. Additionally, EVs can be loaded with exogenous cargo, and have features such as high stability and favorable pharmacokinetic properties. This makes them ideal for tumor-targeted delivery of biological moieties. The International Society of Extracellular Vesicles (ISEV) based on the Minimal Information for Studies on Extracellular Vesicles (MISEV) recommends the usage of the term "small extracellular vesicles (sEVs)" that includes exosomes for particles that are 30-200 nm in size. However, majority of the studies reported in the literature and relevant to this review have used the term "exosomes". Therefore, this review will use the term "exosomes" interchangeably with sEVs for consistency with the literature and avoid confusion to the readers. This review, initially summarizes the different isolation and detection techniques developed to study ovarian cancer-derived exosomes and the potential use of these exosomes as biomarkers for the early diagnosis of this devastating disease. It addresses the role of exosome contents in the pathogenesis of ovarian cancer, discusses strategies to limit exosome-mediated ovarian cancer progression, and provides options to use exosomes for tumor-targeted therapy in ovarian cancer. Finally, it states future research directions and recommends essential research needed to successfully transition exosomes from the laboratory to the gynecologic-oncology clinic.


Subject(s)
Biomarkers, Tumor , Exosomes , Ovarian Neoplasms , Humans , Exosomes/metabolism , Female , Ovarian Neoplasms/therapy , Ovarian Neoplasms/diagnosis , Ovarian Neoplasms/metabolism
4.
Chemistry ; : e202401325, 2024 May 02.
Article in English | MEDLINE | ID: mdl-38698535

ABSTRACT

Chiral secondary alcohols, serving as essential structural motifs, hold significant potential for diverse applications. The exploration of effective synthetic strategies toward these compounds is both attractive and challenging. Herein, we present an asymmetric oxa-Michael reaction involving aliphatic alcohols as nucleophiles and ß-fluoroalkyl vinylsulfones catalyzed by bifunctional phosphonium salt (BPS), achieving high yields and excellent enantioselectivities (up to 98% yield and 98% ee). Additionally, a sequential process including asymmetric oxa-Michael and debenzylation, facilitated by BPS/Lewis acid cooperation, was revealed for synthesizing diverse chiral secondary alcohol compounds in high yields (81-88%) with consistent stereoselectivities. Furthermore, mechanistic explorations and subsequent results unveiled that the enantioselectivity originates from hydrogen-bonding and ion-pair interactions between the BPS catalyst and the substrates.

5.
Environ Pollut ; 350: 123937, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38631453

ABSTRACT

Per- and poly-fluoroalkyl substances (PFAS) have been reported to have hepatotoxic effects. However, it is unclear whether they are linked to non-alcoholic fatty liver disease (NAFLD). This nested case-control study focused on the epidemiological links between PFAS and the prevalence of NAFLD. We selected 476 new cases of NAFLD and 952 age- and sex-matched controls from the Jinchang cohort population between 2014 and 2019. Serum concentrations of PFAS were measured using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Only PFAS with a detection rate of ≥90 % were included for analysis, which included PFPeA, PFOA, PFNA, PFHxS, PFOS, and 9Cl-PF3ONS. The relationship between single and co-exposure to PFAS and the occurrence of NAFLD was evaluated using conditional logistic regression, Quantile g-computation (QgC), and Bayesian kernel machine regression (BKMR) model. Logistic regression indicated that PFPeA, PFOA, and 9Cl-PF3ONS were positive correlation with the incidence of NAFLD after adjusting for confounders, with odds ratios (OR) and 95 % confidence interval (CI) of 3.13 (95 % CI: 2.53, 3.86), 1.39 (95 % CI: 1.12, 1.73), and 1.41 (95 % CI: 1.20, 1.66), respectively. PFNA, PFHxS, and PFOS were nonlinearly and negatively associated with the incidence of NAFLD, with OR (95 % CI) of 0.53 (0.46, 0.62), 0.83 (0.73, 0.95), and 0.52 (0.44, 0.61), respectively. QgC showed a significant joint effect of PFAS mixture on NAFLD onset (OR: 1.52, 95 % CI: 1.24, 1.88). BKMR showed a weak positive trend between PFAS mixtures and NAFLD incidence. Positive correlations were primarily driven by PFPeA and 9Cl-PF3ONS, while negative correlations were mainly influenced by PFNA and PFOS. The BKMR model also suggested that there was an interaction between PFOS and PFNA and other four PFAS compounds. In conclusion, our findings suggest that individual and co-exposure to PFAS is associated with a risk of NAFLD onset.


Subject(s)
Environmental Pollutants , Fluorocarbons , Non-alcoholic Fatty Liver Disease , Non-alcoholic Fatty Liver Disease/epidemiology , Non-alcoholic Fatty Liver Disease/chemically induced , Case-Control Studies , Humans , Fluorocarbons/blood , China/epidemiology , Male , Female , Middle Aged , Environmental Pollutants/blood , Adult , Environmental Exposure/statistics & numerical data
6.
J Am Chem Soc ; 146(10): 6675-6685, 2024 Mar 13.
Article in English | MEDLINE | ID: mdl-38427024

ABSTRACT

Peptide stapling is recognized as an effective strategy for improving the proteolytic stability and cell permeability of peptides. In this study, we present a novel approach for the site-selective unsymmetric perfluoroaryl stapling of Ser and Cys residues in unprotected peptides. The stapling reaction proceeds smoothly under very mild conditions, exhibiting a remarkably rapid reaction rate. It can furnish stapled products in both liquid and solid phases, and the presence of nucleophilic groups other than Cys thiol within the peptide does not impede the reaction, resulting in uniformly high yields. Importantly, the chemoselective activation of Ser ß-C(sp3)-H enables the unreacted -OH to serve as a reactive handle for subsequent divergent modification of the staple moiety with various therapeutic functionalities, including a clickable azido group, a polar moiety, a lipid tag, and a fluorescent dye. In our study, we have also developed a visible-light-induced chemoselective C(sp3)-H polyfluoroarylation of the Ser ß-position. This reaction avoids interference with the competitive reaction of Ser -OH, enabling the precise late-stage polyfluoroarylative modification of Ser residues in various unprotected peptides containing other highly reactive amino acid residues. The biological assay suggested that our peptide stapling strategy would potentially enhance the proteolytic stability and cellular permeability of peptides.


Subject(s)
Amino Acids , Peptides , Peptides/chemistry , Sulfhydryl Compounds/chemistry , Fluorescent Dyes , Peptide Hydrolases
7.
Angew Chem Int Ed Engl ; 63(22): e202403707, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38520267

ABSTRACT

Despite the significance of chiral allene skeletons in catalysis, organic synthesis and medicinal chemistry et al., there is a scarcity of reports on axially chiral allenyl phosphorus compounds. Here, we disclosed an efficient and straightforward cascade reaction between ethynyl ketones and phosphine oxides, resulting in a broad array of trisubstituted allenes incorporating a phosphorus moiety in high yields with excellent stereoselectivities facilitated by peptide-mimic phosphonium salt (PPS) catalysis, Additionally, comprehensive series of mechanistic experiments have been conducted to elucidate that this cascade reaction proceeds via an asymmetric Pudovik addition reaction followed by a subsequent phospha-Brook rearrangement that occurs concomitantly with kinetic resolution, representing a stereospecific rearrangement and protonation process facilitating central-to-axial chirality transfer in a cascade manner. We anticipate that our research will pave the way for a promising exploration of novel stereo-induction pattern in the Pudovik addition/phospha-Brook rearrangement cascade reaction.

8.
Heliyon ; 10(3): e25299, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38317934

ABSTRACT

Artificial precipitation enhancement (APE) activities have been applied extensively around the world to enhance water resources. However, the transport way of the silver iodide catalyst utilized remains completely unknown. To address this issue, in this study, we monitored the content of silver ions (Ag+) in a water body under the influence of APE for a period of 16 years (2004-2019). Additionally, we monitored the content of silver ions in the multi-period rainfall and soil. Our findings indicate that after the APE operation, the detected silver content in the precipitation initially demonstrated an upward trend and then decreased to 0. Furthermore, we observed that some of the silver ions remained in the air for a period extending from the time of artificial rain till the next rain. The silver ion content in the soil during the flood season was elevated by 44 % in comparison to the non-operation period; the concentration of silver ions in the water body during the operation period was 42.86 % higher than that in the non-operation period. During the long-term study, spanning 16 years, the water body played a leading role in regulating the content of silver ions released by the APE, resulting in an increase in silver ion content by 3.3 %. Our results revealed the presence of silver in the precipitation after the APE operation, indicating that silver iodide initially entered the precipitation after catalysis. Furthermore, upon the comparison of the soil and surface water during the operation period and non-operation period, the silver content during the operation period was observed to be higher than that in the non-operation period, indicating that silver iodide was incorporated into the underlying surface from the precipitation. Therefore, we have concluded that the transport pathway of silver involves its initial entry into precipitation after sowing, subsequently descending with the precipitation to reach the soil and surface water. The findings of this study establish a scale ruler for the impact of increasing global APE activities on the environment, as well as first-hand data for preventing possible future environmental risks.

9.
Bone ; 181: 117025, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38272435

ABSTRACT

INTRODUCTION: We examined the association between physical activity (PA) and sedentary behavior (SEB) time with bone health and whether it changes depending on different patterns. MATERIALS AND METHODS: Cross-sectional data were derived from the baseline of the Physical Activity and Health in Older Women Study. PA and SEB were measured using Actigraph wGT3X-BT accelerometers. Bone mineral density (BMD) was derived from the SONOST-2000 ultrasound bone densitometer, with unhealthy bone defined as a BMD T-score of <2.5 standard deviation a young adult reference population's mean. A 10 min-bouted SEB was defined as an SEB duration of >10 min (allow 2 min 0 counts), similar to 30 min-bouted and 60 min-bouted SEBs. Sporadic and bouted PAs were defined by PA duration of <10 min or ≥ 10 min. Multivariate logistic regression analysis investigated the associations between PA and SEB patterns with bone health. RESULTS: Among 1111 female participants, 42.12 % had unhealthy bones. In a fully-adjusted model, increasing 30 min/day of SEB was associated with a higher odds ratio (OR) for an unhealthy bone (OR, 1.08; P = 0.005), similar to the 10 (OR, 1.06; P = 0.012), 30 (OR, 1.06; P = 0.043), and 60 min-bouted (OR 1.08, P = 0.032) SEBs. Total light PA (LPA) time (OR, 0.97; P = 0.005) had a lower OR for unhealthy bone. After adjusting for sporadic LPA time, bouted LPA (OR, 0.97; P = 0.005) retained this association. No association was observed between total moderate-to-vigorous PA (MVPA) and bone health, sporadic MVPA, and bouted MVPA. CONCLUSIONS: Performing bouted LPA and reducing 10 min-bouted SEB may maintain bone health.


Subject(s)
Bone Density , Sedentary Behavior , Young Adult , Humans , Female , Aged , Cross-Sectional Studies , Exercise , China , Accelerometry
10.
Int J Numer Method Biomed Eng ; 40(3): e3807, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38281812

ABSTRACT

Endovascular coiling is the predominant method for treating cerebral aneurysms. Extensive reports on selecting coil length, hardness, and material are available. However, the impact of coil diameter on postoperative outcomes remains unclear. This study enrolled six personalized geometric models of intracranial aneurysms: three bifurcation aneurysms and three sidewall aneurysms. Four coil models were constructed by changing the coil diameter. Coil embolization was simulated using the finite element method. Computational fluid dynamics was used to characterize hemodynamics in the aneurysms after embolization. Evaluation parameters included velocity reduction, wall shear stress (WSS), low WSS (LWSS), oscillatory shear index (OSI), relative residence time (RRT), and residual flow volume in the aneurysms. At the peak time (t = 0.17 s), the proportion of LWSS area in bifurcation aneurysms increase with the rise in coil diameter: 0.8D, 71.28 ± 12.62% versus 1D, 74.97 ± 19.17% versus 1.2D, 78.88 ± 18.56% versus 1.4D, 84.00 ± 11.53% (mean ± SD). The proportion of high OSI area decreases as the coil diameter increases: 0.8D, 4.41% ± 2.82% versus 1.0D, 3.78 ± 3.33% versus 1.2D, 2.28% ± 1.77% versus 1.4D, 1.58% ± 1.11% (mean ± SD). The proportion of high RRT area increases as the coil diameter rises: 0.8D, 3.40% ± 1.68% versus 1.0D, 7.67 ± 4.12% versus 1.2D, 9.84% ± 9.50% versus 1.4D, 22.29% ± 14.28% (mean ± SD). Side wall aneurysms do not exhibit the aforementioned trend. Bifurcation aneurysms plugged with a coil of 1.4 times the diameter have the largest RFVs (<10 mm/s) within the group. Aforementioned patterns are not found in sidewall aneurysms. In the treatment of aneurysms with coiling, varying coil diameters can result in different hemodynamic environments within the aneurysm. Larger coil diameters have improved hemodynamic performance for bifurcation aneurysms. However, coil diameter and embolization effectiveness have no significant relationship for sidewall aneurysms.


Subject(s)
Embolization, Therapeutic , Intracranial Aneurysm , Humans , Intracranial Aneurysm/surgery , Hemodynamics , Blood Vessel Prosthesis , Embolization, Therapeutic/methods , Hydrodynamics
11.
EMBO Rep ; 25(3): 971-990, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38279020

ABSTRACT

Tumor metastasis involves cells migrating directionally in response to external chemical signals. Reactive oxygen species (ROS) in the form of H2O2 has been demonstrated as a chemoattractant for neutrophils but its spatial characteristics in tumor microenvironment and potential role in tumor cell dissemination remain unknown. Here we investigate the spatial ROS distribution in 3D tumor spheroids and identify a ROS concentration gradient in spheroid periphery, which projects into a H2O2 gradient in tumor microenvironment. We further reveal the role of H2O2 gradient to induce chemotaxis of tumor cells by activating Src and subsequently inhibiting RhoA. Finally, we observe that the absence of mitochondria cristae remodeling proteins including the mitochondria-localized actin motor Myosin 19 (Myo19) enhances ROS gradient and promotes tumor dissemination. Myo19 downregulation is seen in many tumors, and Myo19 expression is negatively associated with tumor metastasis in vivo. Together, our study reveals the chemoattractant role of tumor microenvironmental ROS and implies the potential impact of mitochondria cristae disorganization on tumor invasion and metastasis.


Subject(s)
Chemotaxis , Hydrogen Peroxide , Reactive Oxygen Species , Myosins/metabolism , Chemotactic Factors
12.
J Control Release ; 365: 286-300, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37992875

ABSTRACT

Multidrug resistance (MDR) is an inevitable clinical problem in chemotherapy due to the activation of abundant P-glycoprotein (P-gp) that can efflux drugs. Limitations of current cancer therapy highlight the need for the development of a comprehensive cancer treatment strategy, including drug-resistant cancers. Small extracellular vesicles (sEVs) possess significant potential in surmounting drug resistance as they can effectively evade the efflux mechanism and transport small molecules directly to MDR cancer cells. One mechanism mediating MDR in cancer cells is sustaining increased levels of reactive oxygen species (ROS) and maintenance of the redox balance with antioxidants, including glutathione (GSH). Herein, we developed GSH-depleting benzoyloxy dibenzyl carbonate (B2C)-encapsulated sEVs (BsEVs), which overcome the efflux system to exert highly potent anticancer activity against human MDR ovarian cancer cells (OVCAR-8/MDR) by depleting GSH to induce oxidative stress and, in turn, apoptotic cell death in both OVCAR-8/MDR and OVCAR-8 cancer cells. BsEVs restore drug responsiveness by inhibiting ATP production through the oxidation of nicotinamide adenine dinucleotide with hydrogen (NADH) and inducing mitochondrial dysfunction, leading to the dysfunction of efflux pumps responsible for drug resistance. In vivo studies showed that BsEV treatment significantly inhibited the growth of OVCAR-8/MDR and OVCAR-8 tumors. Additionally, OVCAR-8/MDR tumors showed a trend towards a greater sensitivity to BsEVs compared to OVCAR tumors. In summary, this study demonstrates that BsEVs hold tremendous potential for cancer treatment, especially against MDR cancer cells.


Subject(s)
Antineoplastic Agents , Neoplasms , Humans , Antineoplastic Agents/pharmacology , Reactive Oxygen Species/metabolism , Pharmaceutical Preparations , Drug Resistance, Neoplasm , Cell Line, Tumor , Neoplasms/drug therapy
13.
Sci Total Environ ; 914: 169695, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38160829

ABSTRACT

The rapid development of marine aquaculture has led to the increased use and release of antibiotics into the marine environment, consequently contributing to the emergence of antibiotic resistance. Information on antibiotic resistance in nearshore marine aquaculture areas remains limited, and research on the microbial composition and potential hosts of antibiotic resistance genes (ARGs) in marine aquaculture areas is scarce. This study used SmartChip real-time fluorescent quantitative PCR and qPCR to quantitatively analyze 44 ARGs and 10 mobile genetic elements (MGEs) genes in 12 sampling points in the nearshore aquaculture area of Wenchang. High-throughput sequencing of 16S rRNA was used to study microbial diversity in the study area, to clarify the correlation between ARGs, MGEs, and microbial diversity, and to determine the possible sources and potential hosts of ARGs. The results showed that a total of 37 ARGs and 8 MGEs were detected in the study area. The detection rate of 9 ARGs (aac(6')-Ib(aka aacA4)-02, catA1, cmlA, cfr, sul1, sul2, sulA/folP-01, tetC, tetX) was 100 %. The absolute abundance of ARGs in the 12 sampling points ranged from 2.75 × 107 to 3.79 × 1010 copies·L-1, and the absolute abundance of MGEs was 1.30 × 105 to 2.54 × 107 copies·L-1, which was relatively high compared to other research areas. ARGs and MGEs were significantly correlated, indicating that MGEs play an important role as a mediator in the spread of ARGs. At the phylum level, Proteobacteria and Cyanobacteria were the dominant bacteria in the study area, with HIMB11 and unidentifiedChloroplast being the dominant levels, respectively. Network analysis of ARGs and microorganisms (genus level) revealed that Cognatishimia, Thalassobius, Aestuariicoccus, Thalassotalea, and Vibrio were significantly correlated with multiple ARGs and were the main potential hosts of ARGs in the nearshore waters of Wenchang.


Subject(s)
Anti-Bacterial Agents , Genes, Bacterial , Anti-Bacterial Agents/analysis , RNA, Ribosomal, 16S/genetics , Drug Resistance, Microbial/genetics , China , Aquaculture
14.
Org Lett ; 26(1): 292-297, 2024 Jan 12.
Article in English | MEDLINE | ID: mdl-38157220

ABSTRACT

The diaryl ether represents a prevalent structural motif found in numerous biologically active molecules. Herein, we describe a dirhodium-catalyzed C(sp2)-O cross coupling reaction between diazo quinones and phenols for the construction of diaryl ethers in moderate to high yields. The reaction proceeds under mild and neutral conditions and is tolerant of various functional groups. The synthetic method has been successfully applied to the concise synthesis of a Navl.7 inhibitor.

15.
Nat Commun ; 14(1): 8440, 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-38114531

ABSTRACT

Autophagy receptor NDP52 triggers bacterial autophagy against infection. However, the ability of NDP52 to protect against viral infection has not been established. We show that NDP52 binds to envelope proteins of hepatitis B virus (HBV) and triggers a degradation process that promotes HBV clearance. Inactivating NDP52 in hepatocytes results in decreased targeting of viral envelopes in the lysosome and increased levels of viral replication. NDP52 inhibits HBV at both viral entry and late replication stages. In contrast to NDP52-mediated bacterial autophagy, lysosomal degradation of HBV envelopes is independent of galectin 8 and ATG5. NDP52 forms complex with Rab9 and viral envelope proteins and links HBV to Rab9-dependent lysosomal degradation pathway. These findings reveal that NDP52 acts as a sensor for HBV infection, which mediates a unique antiviral response to eliminate the virus. This work also suggests direct roles for autophagy receptors in other lysosomal degradation pathways than canonical autophagy.


Subject(s)
Hepatitis B virus , Hepatitis B , Humans , Hepatitis B virus/physiology , Hepatocytes/metabolism , Autophagy/physiology , Lysosomes/metabolism , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Antiviral Agents/metabolism , Virus Replication/physiology
16.
Micromachines (Basel) ; 14(12)2023 Nov 30.
Article in English | MEDLINE | ID: mdl-38138367

ABSTRACT

The increasing demand for accurate imaging spectral information in remote sensing detection has driven the development of hyperspectral remote sensing instruments towards a larger view field and higher resolution. As the core component of the spectrometer slit, the designed length reaches tens of millimeters while the precision maintained within the µm level. Such precision requirements pose challenges to traditional machining and laser processing. In this paper, a high-precision air slit was created with a large aspect ratio through MEMS technology on SOI silicon wafers. In particular, a MEMS slit was prepared with a width of 15 µm and an aspect ratio exceeding 4000:1, and a spectral spectroscopy system was created and tested with a Hg-Cd light source. As a result, the spectral spectrum was linear within the visible range, and a spectral resolution of less than 1 nm was obtained. The standard deviation of resolution is only one-fourth of that is seen in machined slits across various view fields. This research provided a reliable and novel manufacturing technique for high-precision air slits, offering technical assistance in developing high-resolution wide-coverage imaging spectrometers.

17.
Article in English | MEDLINE | ID: mdl-37929797

ABSTRACT

Mitochondria are the powerhouse of the cell and play important roles in multiple cellular processes including cell metabolism, proliferation, and programmed cell death. Mitochondria are double-membrane organelles with the inner membrane folding inward to form cristae. Mitochondria networks undergo dynamic fission and fusion. Deregulation of mitochondrial structure has been linked to perturbed mitochondrial membrane potential and disrupted metabolism, as evidenced in tumorigenesis, neurodegenerative diseases, etc. Actin and its motors-myosins have long been known to generate mechanical forces and participate in short-distance cargo transport. Accumulating knowledge from biochemistry and live cell/electron microscope imaging has demonstrated the role of actin filaments in pre-constricting the mitochondria during fission. Recent studies have suggested the involvement of myosins in cristae maintenance and mitochondria quality control. Here, we review current findings and discuss future directions in the emerging fields of cytoskeletal regulation in cristae formation, mitochondrial dynamics, intracellular transport, and mitocytosis, with focus on the actin cytoskeleton and its motor proteins.

18.
Prev Med ; 175: 107722, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37783314

ABSTRACT

AIMS: To examine the association between daily steps and step intensity with bone health in Chinese community-dwelling older women. METHODS: Data from 1116 women in the Physical Activity and Health in Older Women Study in China, 2021. Three bone parameters: bone quality index (BQI), speed of sound (SOS), and broadband ultrasound attenuation (BUA) were measured in the left heel using an ultrasound bone densitometer and transformed into dichotomous variables from medians. Daily steps and step intensity (slow step time, brisk step time, peak 1-min cadence, peak 30-min cadence, and peak 60-min cadence) were measured using a triaxial accelerometer. Participants with high BQI, SOS, and BUA levels were used as references for logistic regression models to explore the association of daily steps and step intensity with bone health. RESULTS: Daily steps were positively associated with the BQI (odds ratio [OR] = 0.94, confidence interval [CI] = 0.89,1.00), SOS (OR = 0.93, CI = 0.88,0.99), and BUA (OR = 0.93, CI = 0.88,0.99) among older women. There was no significant association between peak cadence and bone health. Slow step time was positively associated with the BQI (OR = 0.94, CI = 0.90,0.99) and SOS (OR = 0.93, CI = 0.88,0.97), while brisk step time was positively associated with the BQI (OR = 0.89, CI = 0.82,0.97), SOS (OR = 0.87, CI = 0.80,0.94), and BUA (OR = 0.89, CI = 0.82,0.97). Moreover, 10,000 steps/day or more was significantly associated with the BQI (OR = 0.52, CI = 0.33,0.81), SOS (OR = 0.55, CI = 0.35,0.86), and BUA (OR = 0.45, CI = 0.28, 0.70) compared to <6000 steps/day. CONCLUSION: Increasing the number of daily steps or the duration of walking, whether fast or slow, may benefit the bone health of older women.


Subject(s)
Bone Density , Independent Living , Humans , Female , Aged , Cross-Sectional Studies , Walking , Ultrasonography , China
19.
Ann Dyslexia ; 73(3): 487-509, 2023 10.
Article in English | MEDLINE | ID: mdl-37422551

ABSTRACT

Within the framework of the theory of visual attention (TVA), the visual attention span (VAS) deficit among individuals with developmental dyslexia has been ascribed to the problems entailed by bottom-up (BotU) and top-down (TopD) attentional processes. The former involves two VAS subcomponents: the visual short-term memory storage and perceptual processing speed; the latter consists of the spatial bias of attentional weight and the inhibitory control. Then, what about the influences of the BotU and TopD components on reading? Are there differences in the roles of the two types of attentional processes in reading? This study addresses these issues by using two types of training tasks separately, corresponding to the BotU and TopD attentional components. Three groups of Chinese children with dyslexia-15 children each in the BotU training, TopD training, and non-trained active control groups were recruited here. Participants completed reading measures and a CombiTVA task which was used to estimate VAS subcomponents, before and after the training procedure. Results showed that BotU training improved both the within-category and between-category VAS subcomponents and sentence reading performance; meanwhile, TopD training enhanced character reading fluency through improving spatial attention capacity. Moreover, benefits on attentional capacities and reading skills in the two training groups were generally maintained three months after the intervention. The present findings revealed diverse patterns in the influences of VAS on reading within the TVA framework, which contributes to enriching the understanding of VAS-reading relation.


Subject(s)
Attention , Dyslexia , Reading , Visual Perception , Child , Humans , Dyslexia/therapy , East Asian People , Memory, Short-Term
20.
Article in English | MEDLINE | ID: mdl-37453026

ABSTRACT

A high ethanol usage of alcohol oxidase (AOX) was required in industry. In this study, a "expand substrate pocket" strategy achieved a high activity AOX from Hansenula polymorpha (H. polymorpha) by Phe to Val residue (F/V) site-directed mutation to enlarge ethanol channel. Although H. Polymorpha AOX (HpAOX) possessed respectively 71.3% and 76.1% similarity with AOX (PpAOX) from Pichia pastoris (P. pastoris) in DNA and protein sequences, their active site structures including catalytic site and substrate channel were similar according to computer-aided analysis. After 3D structure analysis, Phe99 residue of their substrate channels was the most important residue to impact enzyme activity because of its large aromatic side chains. F99V mutation of HpAOX (HpAOXF99V) was designed and executed based on the enzyme catalytic mechanism and molecular computation in order to allow more larger size ethanol into active site. The highest enzyme activity of the fourth strains of HpAOXF99V mutant strain exhibited 12.06-folds increase than that of the host GS115 strain. Furthermore, kinetic studies indicated that the HpAOXF99V significantly promoted catalytic efficiency of ethanol than HpAOX, including Km, Vmax, kcat and kcat/Km. We also provided a new insight that the cofactor FAD irritated both active AOX octamer biosynthesis production and enzyme-catalysed ability due to help enzyme assembly and redox potential.

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