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1.
Artigo em Inglês | MEDLINE | ID: mdl-35040616

RESUMO

Fe-based nanomaterials with Fenton reaction activity are promising for tumor-specific chemodynamic therapy (CDT). However, most of the nanomaterials suffer from low catalytic efficiency due to its insufficient active site exposure and the relatively high tumor intracellular pH, which greatly impede its clinical application. Herein, macrophage membrane-camouflaged carbonic anhydrase IX inhibitor (CAI)-loaded hollow mesoporous ferric oxide (HMFe) nanocatalysts are designed to remodel the tumor microenvironment with decreased intracellular pH for self-amplified CDT. The HMFe not only serves as a Fenton agent with high active-atom exposure to enhance CDT but also provides hollow cavity for CAI loading. Meanwhile, the macrophage membrane-camouflaging endows the nanocatalysts with immune evading capability and improves tumoritropic accumulation by recognizing tumor endothelium and cancer cells through α4/VCAM-1 interaction. Once internalized by tumor cells, the CAI could be specifically released, which can not only inhibit CA IX to induce intracellular H+ accumulation for accelerating the Fenton reaction but also could prevent tumor metastasis because of the insufficient H+ formation outside cells for tumor extracellular matrix degradation. In addition, the HMFe can be employed to highly efficient magnetic resonance imaging to real-time monitor the agents' bio-distribution and treatment progress. Both in vitro and in vivo results well demonstrated that the nanocatalysts could realize self-amplified CDT and breast cancer metastasis inhibition via tumor microenvironment remodeling, which also provides a promising paradigm for improving CDT and antimetastatic treatment.

3.
Chemosphere ; 286(Pt 3): 131758, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34399255

RESUMO

Wasted polyethylene (PE) products caused pollution has become a global issue. Researchers have identified PE-degrading bacteria which have been considered as a sustainable alleviation to this crisis. However, the degradation mechanism employed by currently isolated bacteria is unclear and their degradation efficiencies are insufficient. More importantly, there is little research into bacteria capable of degrading PE mulching film to solve "white" pollution in agriculture. We determined the PE degradation efficiency of two Pseudomonas, identified by 16S rDNA analysis, and elucidated their potential mechanisms through whole genome sequencing. During an 8-week period, PE mulch lost 5.95 ± 0.03% and 3.62 ± 0.32% of its mass after incubated with P. knackmussii N1-2 and P. aeruginosa RD1-3 strains, respectively. Moreover, considerable pits and wrinkles were observed on PE.The hydrophobicity of PE films also decreased, and new oxygenic functional groups were detected on PE mulch by Fourier Transform Infrared Spectrometry (FTIR). Complete genome sequencing analysis indicated that two Pseudomonas strains encode genes for enzymes and metabolism pathways involved in PE degradation. The results provide a theoretical basis for further research that investigates the mechanism driving the degradation and metabolism of discarded PE in the environment.


Assuntos
Polietileno , Pseudomonas , Agricultura , Bactérias , Biodegradação Ambiental , Pseudomonas/genética
4.
Invest Ophthalmol Vis Sci ; 62(15): 1, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34851376

RESUMO

Purpose: The purpose of this study was to determine the longitudinal changes in macular retinal and choroidal microvasculature in normal healthy and highly myopic eyes. Methods: Seventy-one eyes, including 32 eyes with high myopia and 39 healthy control eyes, followed for at least 12 months and examined using optical coherence tomography angiography imaging in at least 3 visits, were included in this study. Fovea-centered 6 × 6 mm scans were performed to measure capillary density (CD) of the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC). The rates of CD changes in both groups were estimated using a linear mixed model. Results: Over a mean 14-month follow-up period, highly myopic eyes exhibited a faster rate of whole image CD (wiCD) loss (-1.44%/year vs. -0.11%/year, P = 0.001) and CD loss in the outer ring of the DCP (-1.67%/year vs. -0.14%/year, P < 0.001) than healthy eyes. In multivariate regression analysis, baseline axial length (AL) was negatively correlated with the rate of wiCD loss (estimate = -0.27, 95% confidence interval [CI] = -0.48 to -0.06, P = 0.012) and CD loss in the outer ring (estimate = -0.33, 95% CI = -0.56 to -0.11, P = 0.005), of the DCP. The CD reduction rates in the SCP and CC were comparable in both groups (all P values > 0.05). Conclusions: The rate of CD loss in the DCP is significantly faster in highly myopic eyes than in healthy eyes and is related to baseline AL. The CD in the outer ring reduces faster in eyes with longer baseline AL.

5.
Adv Healthc Mater ; : e2102060, 2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34894092

RESUMO

The anti-tumor efficacy of single photodynamic therapy (PDT) and radiotherapy (RT) has been greatly affected by inadequate tumor uptake of photo/radiation sensitizers, limited laser penetration depth, and radiation sickness caused by high doses of X-rays. Here, we report a biomimetic coronavirus-inspired hollow mesoporous gadolinium/bismuth nanocarrier loaded with a new NIR photosensitizer HB (referred to as HB@VHMBi-Gd) for magnetic resonance imaging (MRI)-guided synergistic photodynamic-RT. HB@VHMBi-Gd displayed a faster cellular uptake rate than the conventional spherical HMBi-Gd loaded with HB (HB@SHMBi-Gd) because of the rough surface-enhanced adhesion. After intravenous injection, HB@VHMBi-Gd was efficiently delivered to the tumor and rapidly invaded the tumor cells by surface spikes. Interestingly, lysosomal acidity could trigger the degradation of VHMBi-Gd to produce ultrasmall nanoparticles to amplify the X-ray attenuation ability and enhance MRI contrast and radiosensitization. Under laser and X-ray irradiation, HB@VHMBi-Gd significantly enhanced 1 O2 generation from HB to induce activation of caspase 9/3 and inhibition of C-myc, while enhancing hydroxyl radical generation from Bi2 O3 to induce intense DNA breakage. By synergistically inducing cell apoptosis by distinct reactive oxygen species (ROS), HB@VHMBi-Gd exhibited superior anticancer efficacy with ∼90% tumor inhibition. We envision that biomimetic virus-inspired hollow hybrid metal nanoparticles could provide a promising strategy for imaging-guided synergistic photodynamic-RT. This article is protected by copyright. All rights reserved.

6.
Adv Sci (Weinh) ; : e2103498, 2021 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-34923766

RESUMO

Free radical-based anticancer modality has been widely applied to cancer therapies. However, it still faces challenges of low delivery efficiency and poor selectivity of free radical generation specifically toward tumors. Herein, a virus-mimicking hollow mesoporous disulfide-bridged organosilica is designed to encapsulate •C precursor 2, 2'-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIPH), which is then enclosed by tannic acid (TA)/FeIII photothermal assembly and further cloaked by natural killer (NK) cell membrane to achieve synergistic thermodynamic-chemodynamic therapy. The nanogenerator can first evade immune surveillance via NK cell membrane "cloaking" mechanism to strongly accumulate in tumors. Interestingly, the NIR laser-induced heat can trigger NK cell membrane rupture for "shape reversal" to expose a virus-like surface to amplify the cellular uptake, and simultaneously break the azo bonds of AIPH for in situ controlled •C generation. Then upon glutathione (GSH) triggering, the nanogenerator disintegrates via disulfide-thiol exchange and efficiently generates •OH by lysosomal pH-initiated TA-FeIII reaction; notably, the consumption of GSH can amplify oxidative stress to enhance free radical therapy by weakening the self-defense mechanism of tumor cells. It is envisioned that the NK cell membrane-cloaked virus-mimicking and NIR/GSH sequentially activated •C/•OH radical nanogenerator can provide a promising strategy for oxidative stress-based anticancer therapy.

7.
Small Methods ; 5(3): e2001066, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34927825

RESUMO

Near-infrared (NIR) fluorescence imaging is an emerging noninvasive imaging modality, with unique advantages in guiding tumor resection surgery, thanks to its high sensitivity and instantaneity. In the past decade, studies on the conventional NIR window (NIR-I, 750-900 nm) have gradually focused on the second NIR window (NIR-II, 1000-1700 nm). With its reduced light scattering, photon absorption, and auto-fluorescence qualities, NIR-II fluorescence imaging significantly improves penetration depths and signal-to-noise ratios in bio-imaging. Recently, several studies have applied NIR-II imaging to navigating cancer surgery, including localizing cancers, assessing surgical margins, tracing lymph nodes, and mapping important anatomical structures. These studies have exemplified the significant prospects of this new approach. In this review, several NIR-II fluorescence agents and some of the complex applications for guiding cancer surgeries are summarized. Future prospects and the challenges of clinical translation are also discussed.

8.
Invest Ophthalmol Vis Sci ; 62(14): 17, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34787640

RESUMO

High myopia is among the most common causes of vision impairment, and it is mainly characterized by abnormal elongation of the axial length, leading to pathologic changes in the ocular structures. Owing to the close relationship between high myopia and glaucoma, the association between intraocular pressure (IOP) and high myopia progression has garnered attention. However, whether lowering IOP can retard the progression of high myopia is unclear. On reviewing previous studies, we suggest that lowering IOP plays a role in progressive axial length elongation in high myopia, particularly in pathologic myopia, wherein the sclera is more remodeled. Based on the responses of the ocular layers, we further proposed the potential mechanisms. For the sclera, lowering the IOP could inhibit the activation of scleral fibroblasts and then reduce scleral remodeling, and a decrease in the scleral distending force would retard the ocular expansion like a balloon. For the choroid, lowering IOP results in an increase in choroidal blood perfusion, thereby reducing scleral hypoxia and slowing down scleral remodeling. The final effect of these pathways is slowing axial elongation and the development of scleral staphyloma. Further animal and clinical studies regarding high myopia with varied degree of IOP and the changes of choroid and sclera during IOP fluctuation in high myopia are needed to verify the role of IOP in the pathogenesis and progression of high myopia. It is hoped that this may lead to the development of a prospective treatment option to prevent and control high myopia progression.

9.
Adv Sci (Weinh) ; 8(23): e2103334, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34664422

RESUMO

The synergistic combination of chemotherapy and photodynamic therapy has attracted considerable attention for its enhanced antitumoral effects; however, it remains challenging to successfully delivery photosensitizers and anticancer drugs while minimizing drug leakage at off-target sites. A red-light-activatable metallopolymer, Poly(Ru/PTX), is synthesized for combined chemo-photodynamic therapy. The polymer has a biodegradable backbone that contains a photosensitizer Ru complex and the anticancer drug paclitaxel (PTX) via a singlet oxygen (1 O2 ) cleavable linker. The polymer self-assembles into nanoparticles, which can efficiently accumulate at the tumor sites during blood circulation. The distribution of the therapeutic agents is synchronized because the Ru complex and PTX are covalently conjugate to the polymer, and off-target toxicity during circulation is also mostly avoided. Red light irradiation at the tumor directly cleaves the Ru complex and produces 1 O2 for photodynamic therapy. Sequentially, the generated 1 O2 triggers the breakage of the linker to release the PTX for chemotherapy. Therefore, this novel sequential dual-model release strategy creates a synergistic chemo-photodynamic therapy while minimizing drug leakage. This study offers a new platform to develop smart delivery systems for the on-demand release of therapeutic agents in vivo.

10.
Ann Transl Med ; 9(16): 1330, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34532467

RESUMO

Background: Lung squamous cell carcinoma (LUSC) is characterized by frequent mutations of tumor protein p53 (TP53) and cyclin dependent kinase inhibitor 2A (CDKN2A). However, to date, the impact of TP53/CDKN2A status on the clinical outcome of patients with early-stage LUSC is unclear. Methods: Tissue samples from 16 early-stage, surgically resected LUSCs were analyzed by next-generation sequencing (NGS). Information regarding TP53 and CDKN2A alterations and patient survival time was downloaded from The Cancer Genome Atlas (TCGA) database. The associations between TP53 and CDKN2A status and tumor characteristics, outcomes including overall survival (OS) and disease-free survival (DFS), and mutation counts were investigated. Results: TP53 and CDKN2A exhibited a high frequency of somatic mutations in early-stage LUSC in our center. Data for 1,176 samples were collected from TCGA. CDKN2A mutation status was associated with TP53 mutation status (P=0.040). TP53 mutation was a favorable prognostic factor for early-stage LUSC. The OS times of patients with wild-type and mutated TP53 were 28.94 and 60.48 months, respectively (P=0.002). In contrast, CDKN2A mutations were significantly associated with a shorter survival time in early-stage LUSC. The OS times for wild-type and mutated CDKN2A patients were 62.81 and 37.55 months, respectively (P=0.026). Patients with TP53 mutations had higher total mutation counts compared to patients with wild-type TP53. Furthermore, OS was significantly shorter in patients with a low mutation count compared to patients with a median or high mutation count. Conclusions: Early-stage LUSC patients with TP53 mutations had a longer OS, while those with CDKN2A mutations had a shorter OS. Furthermore, patients with TP53 mutation/CDKN2A wild-type status had a longer OS. CDKN2A mutation is a vital indicator for prognostic assessment according to TP53 status. The prolonged survival of patients with TP53 mutations may be due to their high mutation counts. Larger datasets are required to validate these observations.

11.
ACS Appl Mater Interfaces ; 13(37): 44013-44027, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34494427

RESUMO

Synergetic therapy includes the combination of two or more conventional therapeutic approaches and can be used for tumor treatment by combining the advantages and avoiding the drawbacks of each type of treatment. In the present study, truncated tissue factor (tTF)-EG3287 fusion protein-encapsulated gold nanorod (GNR)-virus-inspired mesoporous silica core-shell nanoparticles (vinyl hybrid silica nanoparticles; VSNP) (GNR@VSNP-tTF-EG3287) were synthesized to achieve synergetic therapy by utilizing selective vascular thrombosis therapy (SVTT) and photothermal therapy (PTT). By integrating the targeted coagulation activity of tTF-EG3287 and the high tumor ablation effect of GNR@VSNP, local hyperthermia could induce a high percentage of apoptosis of vascular endothelial cells by using near-infrared light. This provided additional phospholipid sites for tTF-EG3287 and enhanced its procoagulant activity in vitro. In addition, the nanoparticles, which had unique topological viral structures, exhibited superior cellular uptake properties leading to significant antitumor efficacy. The in vivo antitumor results further demonstrated an interaction between SVTT and PTT, whereas the synergetic therapy (SVTT and PTT) achieved an enhanced effect, which was superior to the respective treatment efficacy of each modality or the additive effect of their individual efficacies. In summary, the synthesized GNR@VSNP-tTF-EG3287 exerted synergetic effects and enhanced the antitumor efficiency by avoiding multiple injections and suboptimal administration. These effects simultaneously affected both tumor blood supply and cancer cell proliferation. The data suggested that the integration of SVTT induced by tTF-EG3287 and PTT could provide potential strategies for synergetic tumor therapy.

12.
Ophthalmology ; 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34339778

RESUMO

PURPOSE: To develop and validate a multimodal artificial intelligence algorithm, FusionNet, using the pattern deviation probability plots from visual field (VF) reports and circular peripapillary OCT scans to detect glaucomatous optic neuropathy (GON). DESIGN: Cross-sectional study. SUBJECTS: Two thousand four hundred sixty-three pairs of VF and OCT images from 1083 patients. METHODS: FusionNet based on bimodal input of VF and OCT paired data was developed to detect GON. Visual field data were collected using the Humphrey Field Analyzer (HFA). OCT images were collected from 3 types of devices (DRI-OCT, Cirrus OCT, and Spectralis). Two thousand four hundred sixty-three pairs of VF and OCT images were divided into 4 datasets: 1567 for training (HFA and DRI-OCT), 441 for primary validation (HFA and DRI-OCT), 255 for the internal test (HFA and Cirrus OCT), and 200 for the external test set (HFA and Spectralis). GON was defined as retinal nerve fiber layer thinning with corresponding VF defects. MAIN OUTCOME MEASURES: Diagnostic performance of FusionNet compared with that of VFNet (with VF data as input) and OCTNet (with OCT data as input). RESULTS: FusionNet achieved an area under the receiver operating characteristic curve (AUC) of 0.950 (0.931-0.968) and outperformed VFNet (AUC, 0.868 [95% confidence interval (CI), 0.834-0.902]), OCTNet (AUC, 0.809 [95% CI, 0.768-0.850]), and 2 glaucomatologists (glaucomatologist 1: AUC, 0.882 [95% CI, 0.847-0.917]; glaucomatologist 2: AUC, 0.883 [95% CI, 0.849-0.918]) in the primary validation set. In the internal and external test sets, the performances of FusionNet were also superior to VFNet and OCTNet (FusionNet vs VFNet vs OCTNet: internal test set 0.917 vs 0.854 vs 0.811; external test set 0.873 vs 0.772 vs 0.785). No significant difference was found between the 2 glaucomatologists and FusionNet in the internal and external test sets, except for glaucomatologist 2 (AUC, 0.858 [95% CI, 0.805-0.912]) in the internal test set. CONCLUSIONS: FusionNet, developed using paired VF and OCT data, demonstrated superior performance to both VFNet and OCTNet in detecting GON, suggesting that multimodal machine learning models are valuable in detecting GON.

13.
Front Mol Biosci ; 8: 684262, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34179090

RESUMO

Promotion of apoptosis and suppression of proliferation in tumor cells are popular strategies for developing anticancer drugs. Sinomenine (SIN), a plant-derived alkaloid, displays antitumor activity. However, the mechanism of action of SIN against hepatocellular carcinoma (HCC) is unclear. Herein, several molecular technologies, such as Western Blotting, qRT-PCR, flow cytometry, and gene knockdown were applied to explore the role and mechanism of action of SIN in the treatment of HCC. It was found that SIN arrests HCC cell cycle at G0/G1 phase, induces apoptosis, and suppresses proliferation of HCC cells via down-regulating the expression of membrane-associated RING-CH finger protein 1 (MARCH1). Moreover, SIN induces cell death and growth inhibition through AMPK/STAT3 signaling pathway. MARCH1 expression was silenced by siRNA to explore its involvement in the regulation of AMPK/STAT3 signaling pathway. Silencing MARCH1 caused down-regulation of phosphorylation of AMPK, STAT3 and decreased cell viability and function. Our results suggested that SIN inhibits proliferation and promotes apoptosis of HCC cells by MARCH1-mediated AMPK/STAT3 signaling pathway. This study provides new support for SIN as a clinical anticancer drug and illustrates that targeting MARCH1 could be a novel treatment strategy in developing anticancer therapeutics.

14.
Exp Ther Med ; 21(6): 651, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33968181

RESUMO

Protein kinase (PK) N1, also called PKC-related protein 1, participates in the proliferation, invasion and metastasis of various malignant tumors. However, the role of PKN1 in liver cancer remains to be elucidated. The present study investigated the expression of PKN1 using immunohistochemistry in surgical specimens from 36 patients and analyzed the correlation with VEGF, microvascular density (MVD), cell proliferation index (Ki67) and clinicopathological parameters. PKN1 was highly expressed in hepatocellular carcinoma (HCC) and was positively correlated with histological grading of HCC, Ki67 expression and MVD. PKN1 expression in moderately and poorly differentiated HCC was significantly higher compared with highly differentiated HCC. Expression of PKN1 was positively correlated with Ki67 and MVD, and Ki67 expression was positively correlated with MVD. The effects of PKN1 on proliferation, invasion and apoptosis of liver cancer cells were detected in vitro. Cell viability, migration and invasion were reduced and the apoptosis rate was significantly improved when PKN1 expression was silenced in liver cancer cells. Thus, PKN1 serves an important role in the development and progression of liver cancer. Inhibition of PKN1 activity may provide a promising therapeutic target for liver cancer.

15.
Nanomedicine ; 34: 102381, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33771705

RESUMO

The Gram-positive bacterium Staphylococcus aureus (MRSA) and the Gram-negative bacillus Escherichia coli (E. coli) can be commonly found in diabetic foot ulcers. However, the multi-drug resistant pathogenic bacteria infection is often difficult to eradicate by the conventional antibiotics and easy to spread which can lead to complications such as gangrene or sepsis. In this work, in order to pull through the low cell wall adhesion capability of typical antibacterial Ag nanoparticles, we fabricated biomimic virus-like mesoporous silica coated Ag nanocubes with gentamicin loading, and then the core-shell nanostructure was entrapped in the FDA approved hydrogel dressing. Interestingly, the Ag nanocubes with virus-like mesoporous silica coating are capable of effectively adsorbing on the rigid cell wall of both E. coli and MRSA. The intracellular H2S in natural bacterial environment can induce generation of small Ag nanospheres, which are the ideal antibacterial nanoagents. Combined with the gentamicin delivery, the pathogenic bacteria in diabetic wound can be completely eradicated by our dressing to improve the wound healing procedure. This virus-like core-shell nanostructure sheds light for the future wound healing dressing design to promote the clinical applications on antibacterial eradication.

16.
Br J Radiol ; 94(1120): 20200437, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33684313

RESUMO

OBJECTIVES: To investigate the feasibility of relative CT numbers to periappendiceal fat attenuation as an applicable index for estimating the severity of acute appendicitis. METHODS: In total, 308 consecutive surgery-confirmed acute appendicitis patients and 243 controls with available preoperative CT were analyzed retrospectively. The radiological parameters were appendix diameter, length, and wall thickness as concurrent appendicitis signs. CT numbers of periappendiceal fat, mesenteric fat, subcutaneous fat in the anterior and posterior abdominal wall, retroperitoneal fat, gluteal subcutaneous fat and psoas major muscle were measured, as well as the relative CT numbers of periappendiceal fat compared with other locations. RESULTS: There were 287 suppurative acute appendicitis (SAA) and 21 gangrenous or perforated acute appendicitis (GPAA) cases confirmed by pathology. The CT number of periappendiceal fat was significantly higher in patients than in controls (P<0.01) although there was a wide overlap (-72.33 HU-117.43 HU). Significant differences in relative CT numbers were observed between the groups in gluteal subcutaneous fat (RCTgl) and psoas major muscle (RCTps) (P<0.01). The AUCs of RCTgl and RCTps showed high accuracy to discriminate acute appendicitis from controls (AUC = 0.803, 0.761; 0.854, 0.847) and GPAA from SAA (AUC = 0.905, 0.851). CONCLUSIONS: Attenuation of periappendiceal fat on CT is related to the severity of appendicitis, and relative CT numbers (RCTgl and RCTps) could be an applicable index for severity determination. ADVANCES IN KNOWLEDGE: Periappendiceal fat infiltration is related to the severity of acute appendicitis (especially relative CT number). Other clinical and CT features also need to be considered in the evaluation of inflammation.


Assuntos
Tecido Adiposo/diagnóstico por imagem , Apendicite/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Doença Aguda , Tecido Adiposo/patologia , Adulto , Apendicite/patologia , Apêndice/diagnóstico por imagem , Apêndice/patologia , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Índice de Gravidade de Doença
17.
Exp Brain Res ; 239(5): 1617-1626, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33760958

RESUMO

Age-related declines in fine motor control may impact tool-use and thereby limit functional independence. Most previous research has, however, focused on the effect of aging on gross motor tasks. Few studies have investigated the effects of aging on the strategy or quality of fine motor skills, especially in tool-use, which may better reflect how age impacts complex movement capability. Twenty-two young (ages 19-35) and 18 older adults (ages 58-87) performed a timed upper extremity task using a tool to acquire and transport objects to different locations. Overall task performance was divided into two phases based on 3-D position of the tool: a gross motor phase (object transport) and a fine motor phase (object acquisition). Overall, older adults took longer to complete the task. A linear model indicated that this was due to the duration of the fine motor phase more so than the gross motor phase. To identify age-related differences in the quality of the fine motor phase, we fit three-dimensional ellipsoids to individual data and the calculated the ellipsoid volume. Results demonstrated a significant volume-by-age interaction, whereby increased ellipsoid volume (space the tool occupied) related to increased mean dwell time for the older adult group only; younger adults did not demonstrate this relationship. Additionally, older adults with longer movement times during the fine motor phase also had lower cognitive scores. No age-related differences were observed for the gross motor phase, suggesting that age-related declines in tool-use may be due to changes in fine motor control and cognitive status.


Assuntos
Comportamento de Utilização de Ferramentas , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Humanos , Pessoa de Meia-Idade , Destreza Motora , Movimento , Análise e Desempenho de Tarefas , Extremidade Superior , Adulto Jovem
18.
Opt Lett ; 46(5): 937-940, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33649625

RESUMO

Using ultra-high repetition rate lasers (≥100kHz) is one of the most promising strategies for the next generation of satellite laser ranging (SLR) systems. We present successful 1 MHz repetition rate SLR to targets up to inclined geosynchronous orbits at nighttime. Among those, a maximum return rate of up to 53% was achieved, equivalent to 265 k returns per second for the satellite Swarm-B. In addition, daytime megahertz (MHz) SLR was realized by utilizing a propagated MHz range gate to reduce the massive background noise. In the future, MHz SLR will greatly improve current technology with respect to data amount and data precision, shorter acquisition time, target signature detection, and attitude determination.

20.
Acta Psychol (Amst) ; 214: 103261, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33524606

RESUMO

Age-related declines in motor learning may be related to poor visuospatial function. Thus, visuospatial testing could evaluate older adults' potential for motor learning, which has implications for geriatric motor rehabilitation. To this end, the purpose of this study was to identify which visuospatial test is most predictive of motor learning within older adults. Forty-five nondemented older adults completed six standardized visuospatial tests, followed by three weekly practice sessions on a functional upper-extremity motor task. Participants were re-tested 1 month later on the trained task and another untrained upper-extremity motor task to evaluate the durability and generalizability of motor learning, respectively. Principal component analysis first reduced the dimensions of the visuospatial battery to two principal components for inclusion in a mixed-effects model that assessed one-month follow-up performance as a function of baseline performance and the principal components. Of the two components, only one was related to one-month follow-up. Factor loadings and post hoc analyses suggested that of the six visuospatial tests, the Rey-Osterrieth test (visual construction and memory) was related to one-month follow-up of the trained and untrained tasks. Thus, it may be plausible that older adults' long-term motor learning capacity could be evaluated using the Rey-Osterrieth test, which would be feasible to administer prior to motor rehabilitation to indicate risk of non-responsiveness to therapy.


Assuntos
Envelhecimento , Destreza Motora , Idoso , Humanos , Aprendizagem , Memória , Testes Neuropsicológicos
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