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1.
Phytochemistry ; 221: 114050, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38479586

RESUMO

Under the guidance of antioxidant evaluation combined with molecular networking, six pairs of enantiomeric lignans including seven undescribed ones (1a, 2a/2b-4a/4b), along with five known analogs (1b, 5a/5b-6a/6b) were isolated from Cimicifuga heracleifolia Kom. Their structures were determined by extensive spectroscopic data analysis, including HRESIMS, 1D and 2D NMR, experimental and calculated ECD. All the enantiomeric isolates were evaluated for antioxidation by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2'-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS) free radical scavenging tests. Compounds 1a and 3a/3b exhibited great DPPH and ABTS scavenging activities. The results are of great value for understanding structurally interesting enantiomeric lignans with antioxidant activity from C. heracleifolia in depth and providing its further development in functional evaluation and drug development.


Assuntos
Benzotiazóis , Cimicifuga , Lignanas , Ácidos Sulfônicos , Lignanas/química , Antioxidantes/química , Estrutura Molecular
2.
Bioorg Chem ; 143: 107052, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38171154

RESUMO

Eucommiae Cortex is one of important traditional Chinese medicines (TCMs) used in Asia for preventing and treating osteoporosis induced by estrogen deficiency. However, the low exposure of prototype components in Eucommiae Cortex in vivo is difficult to interpret its efficacy. Under the guidance of UPLC-Q/TOF-MS, 42 metabolites including 32 lignans and 10 phenolics, 21 of which were new compounds, were isolated from rat urine and feces after oral administration of aqueous extract of E. ulmoides Oliv. by various chromatographic techniques. Their structures were determined based on extensive physicochemical analyses and spectral data. Their absolute configurations were determined by experimental and calculated ECD spectra, along with the calculated NMR with DP4 evaluation. Additionally, all isolated metabolites were evaluated for their estrogen-like activities, and there are 15 metabolites having estrogen-like effects after assessing influences in MCF-7 cells. Further, Dual Luciferase Reporter Gene Assay was used to determine their activation with estrogen receptor, M10 and M11 mixtures, M14, M19, M33, M27, M31, M38-M41 could activate ERα, and M19 and M41 could activate ERß. These results not only clarify the pharmacological substances of Eucommiae Cortex, but also provide a basis for guiding its clinical application.


Assuntos
Medicamentos de Ervas Chinesas , Lignanas , Ratos , Animais , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/análise , Cromatografia Líquida de Alta Pressão/métodos , Medicina Tradicional Chinesa , Estrogênios/farmacologia , Lignanas/farmacologia
3.
Rev Sci Instrum ; 95(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38170817

RESUMO

Supercritical fluids (SCFs) can be found in a variety of environmental and industrial processes. They exhibit an anomalous thermodynamic behavior, which originates from their fluctuating heterogeneous micro-structure. Characterizing the dynamics of these fluids at high temperature and high pressure with nanometer spatial and picosecond temporal resolution has been very challenging. The advent of hard x-ray free electron lasers has enabled the development of novel multi-pulse ultrafast x-ray scattering techniques, such as x-ray photon correlation spectroscopy (XPCS) and x-ray pump x-ray probe (XPXP). These techniques offer new opportunities for resolving the ultrafast microscopic behavior in SCFs at unprecedented spatiotemporal resolution, unraveling the dynamics of their micro-structure. However, harnessing these capabilities requires a bespoke high-pressure and high-temperature sample system that is optimized to maximize signal intensity and address instrument-specific challenges, such as drift in beamline components, x-ray scattering background, and multi-x-ray-beam overlap. We present a pressure cell compatible with a wide range of SCFs with built-in optical access for XPCS and XPXP and discuss critical aspects of the pressure cell design, with a particular focus on the design optimization for XPCS.

4.
Food Chem ; 427: 136656, 2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-37393637

RESUMO

The effect of different types of monoglycerides, including monopalmitin, capryl monoglyceride (GMB), and succinylated monoglyceride (GMSA) in combination with palm kernel stearin (PKS) and beeswax (BW), on the formation, crystal network structure, and partial coalescence properties of aerated emulsions (20 % w/w fat) was investigated. The stability of BW and PKS crystals with a 1 % concentration of GMSA and GMB, respectively, in the oil phase was lower than the other crystals. BW-GMSA and PKS-GMB crystals exhibited a lower crystallization rate, higher contact angles and no significant peak shift in the small-angle X-ray scattering results. The BW-GMSA and PKS-GMB emulsions had a lower nucleation rate in the bulk and a higher nucleation rate at the interface, resulting in a higher fraction of crystals adsorbed at the oil/water interface. This reduced the number of interfacial proteins and led to a high degree of partial coalescence and the formation of stable aerated networks.


Assuntos
Monoglicerídeos , Tensoativos , Emulsões/química , Monoglicerídeos/química
5.
Am J Mens Health ; 17(4): 15579883221138190, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37462134

RESUMO

Health status during the reproductive years influences fecundity, fertility, and the future health of males and their offspring. There remains a dearth of literature examining men's preconception health, especially among high-risk populations, such as those with disabilities. The objective of this study was to examine indicators of preconception health, including chronic medical conditions, lifestyle behaviors, and health care utilization, among males of reproductive age with and without disabilities in the United States. Data were from 3,702 males of reproductive age (18-44 years) who participated in the National Health and Nutrition Examination Surveys, 2013-2018. Approximately 14% of males reported having at least one disability related to vision, hearing, cognition, mobility, self-care, or independent living. Among all men, suboptimal preconception health indicators were prevalent including poor or fair self-rated health; low education and household income status; lack of health insurance and no recent utilization of health care and dental care; cigarette smoking; frequent alcohol consumption and binge drinking; marijuana and illegal drug use; obesity; low fruit and vegetable intake and no multi-vitamin use; low physical activity; short sleep durations; depressive symptoms; and hypertension and asthma. Compared to males with no disabilities, males with any disabilities were more likely to have suboptimal preconception health indicators. Strategies to promote and improve sexual health, preconception care, and family planning services among all men are needed. For males with disabilities, specifically, further investigation of their specific health needs related to sex, reproduction, family planning, and fatherhood, as well as interactions with health care providers, is required.


Assuntos
Pessoas com Deficiência , Cuidado Pré-Concepcional , Gravidez , Masculino , Feminino , Humanos , Estados Unidos/epidemiologia , Adolescente , Adulto Jovem , Adulto , Inquéritos Nutricionais , Estilo de Vida , Reprodução , Fatores Socioeconômicos
6.
J Int Med Res ; 51(5): 3000605231171009, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37161265

RESUMO

With the development of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S ribosomal RNA (rRNA) gene sequencing, increasing numbers of new microorganisms are being discovered. In this report, Kerstersia gyiorum was isolated for the first time from the sputum of two elderly patients with neurodegenerative disease, and integrated traditional Chinese and Western medicine was used for treatment. The bacteria's growth characteristics, biochemical reaction characteristics, sensitivity to antibiotics, and the patients' treatment are described, with a review of previous reports.


Assuntos
Alcaligenaceae , Doenças Neurodegenerativas , Idoso , Humanos , Antibacterianos/uso terapêutico , Idioma
7.
BMC Infect Dis ; 23(1): 333, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37198537

RESUMO

BACKGROUND: Sneathia amnii is a conditional pathogen of the female genital tract that is involved in bacterial vaginosis and poor reproductive and perinatal outcomes. Few studies have reported subcutaneous cysts following invasive infection caused by S amnii. CASE PRESENTATION: Here we report the case of a 27-year-old woman who presented with Bartholin's gland cyst due to S amnii infection, and was successfully treated with surgical neostomy and antibiotic agents. The isolate was gram-negative, bacillary, anaerobic, and was identified by polymerase chain reaction (PCR) amplification of the 16 S rRNA. CONCLUSIONS: S amni is an important but underappreciated pathogen that needs further investigation. This report describes the microbial and pathogenic characteristics of S amnii and is expected to provide a valuable reference in obstetric and gynecologic clinical practice.


Assuntos
Glândulas Vestibulares Maiores , Cistos , Feminino , Humanos , Adulto , Glândulas Vestibulares Maiores/microbiologia , Glândulas Vestibulares Maiores/patologia , Glândulas Vestibulares Maiores/cirurgia , Antibacterianos/uso terapêutico , Fusobactérias , Cistos/diagnóstico
8.
Food Chem ; 405(Pt B): 134867, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36435120

RESUMO

The oxidative stability of pecan kernels and its relationship with the in-vitro behavior of oleosomes during storage were analyzed. The oxidation index of oil extracted from pecans stored for 20 days increased significantly. At the same time oleosomes in pecans were damaged, indicating a relationship between oleosomes and the oxidative stability of pecans. The rupture of oleosomes increases contact between oil and oxygen leading to an acceleration of oil oxidation. Further analysis of oleosomes showed that their oil content decreased during storage while their particle size increased significantly. It is possible that hydrolysis of endogenous proteins, especially oleosins, was responsible for the rupture of oleosomes, as seen by Tricine-SDS-PAGE. As a result, the content of free fatty acids and oxidized triacylglycerols in oleosomes increased, whereas the polyunsaturated fatty acids content decreased significantly. An in-vitro model confirmed that rupture of oleosomes led to oil leakage and thus accelerated endogenous oil oxidation.


Assuntos
Carya , Gotículas Lipídicas , Metabolismo dos Lipídeos , Ácidos Graxos não Esterificados , Triglicerídeos
9.
Cell Rep ; 41(11): 111804, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36516778

RESUMO

Fats are essential in healthy diets, but how dietary fats affect immune cell function and overall health is not well understood. Mimicking human high-fat diets (HFDs), which are rich in different fatty acid (FA) components, we fed mice various HFDs from different fat sources, including fish oil and cocoa butter. Mice consuming the fish oil HFD exhibit a hair-loss phenotype. Further studies show that omega-3 (n-3) FAs in fish oil promote atypical infiltration of CD207- (langerin-) myeloid macrophages in skin dermis, which induce hair loss through elevated TNF-α signaling. Mechanistically, epidermal fatty acid binding protein (E-FABP) is demonstrated to play an essential role in inducing TNF-α-mediated hair loss by activating the n-3 FA/ROS/IL-36 signaling pathway in dermal resident macrophages. Absence of E-FABP abrogates fish oil HFD-induced murine hair loss. Altogether, these findings support a role for E-FABP as a lipid sensor mediating n-3 FA-regulated macrophage function and skin health.


Assuntos
Ácidos Graxos Ômega-3 , Óleos de Peixe , Camundongos , Humanos , Animais , Óleos de Peixe/farmacologia , Óleos de Peixe/metabolismo , Dieta Hiperlipídica/efeitos adversos , Fator de Necrose Tumoral alfa/metabolismo , Gorduras na Dieta/farmacologia , Macrófagos/metabolismo , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Ácidos Graxos Ômega-3/metabolismo , Alopecia/metabolismo
10.
Int J Med Robot ; 18(6): e2440, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35848917

RESUMO

PURPOSE: Vision-based tissue tracking is a significant component for building efficient autonomous surgical robot system. While the methodology involves various challenges caused by occlusion, deformation and appearance changes. METHODS: We propose a novel correlation filter tissue tracking framework for minimally invasive surgery. Our model contains the innovative design of synthetic features, a bi-branch is exploited to enhance the response map. An incrementally learnt detector with the novel updating and trigger schemes is embedded to model the re-detection module for capturing the lost target. RESULTS: Promising validation has been conducted on the publicly available tracking benchmark datasets, a surgical tissue tracking dataset based on publicly available Cholec80 dataset has also been developed to focus on the application in intra-operative scenes. CONCLUSIONS: Our proposed framework meets the outstanding performance and surpasses the existing methods. The work demonstrates the feasibility to perform tissue tracking by taking advantage of the correlation filter.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Cirurgia Assistida por Computador , Humanos , Algoritmos , Cirurgia Assistida por Computador/métodos , Procedimentos Cirúrgicos Minimamente Invasivos/métodos
11.
Artigo em Inglês | MEDLINE | ID: mdl-35565038

RESUMO

This study examined product use among pregnant women and new mothers in New York City during the COVID-19 pandemic (July 2020-June 2021). Women reported use of personal care and household cleaning products within the previous month, changes in antibacterial product use, receipt of healthcare provider advice, and opinions on environmental chemicals (n = 320). On average, women used 15 personal care products and 7 household cleaning products. Non-Hispanic Black women used nearly two more personal care products; non-Hispanic Black women, those with a college degree, and essential workers used 1-3 more household cleaning products. Women who were Hispanic or reported their race and ethnicity as Other were two times more likely to use antibacterial personal care products. Non-Hispanic Black, Hispanic, and women who reported their race and ethnicity as Other were 1.5 times more likely to increase antibacterial product use during the pandemic. Nearly all women agreed that environmental chemicals pose health risks and are impossible to avoid, while less than one quarter received advice regarding product use. Product use is a modifiable source of chemical exposures. Results from this study suggest that women may have increased their product use during the pandemic. Healthcare providers may use the current focus on health hygiene to promote discussion and assessment of environmental chemical exposures with patients.


Assuntos
COVID-19 , Cosméticos , Antibacterianos , COVID-19/epidemiologia , Feminino , Humanos , Mães , Pandemias , Gravidez , Gestantes
12.
J Digit Imaging ; 35(4): 923-937, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35266089

RESUMO

Vision-based detection and tracking of surgical instrument are attractive because it relies purely on surgical instrument already in the operating scenario. The vision knowledge of the surgical instruments is a crucial piece of topic for surgical task understanding, autonomous robot control and human-robot collaborative surgeries to enhance surgical outcomes. In this work, a novel method has been demonstrated by developing a multitask lightweight deep neural network framework to explore surgical instrument articulated joint detection. The model has an end-to-end architecture with two branches, which share the same high-level visual features provided by a lightweight backbone while holding respective layers targeting for specific tasks. We have designed a novel subnetwork with joint detection branch and an instrument classification branch to sufficiently take advantage of the relatedness of surgical instrument presence detection and surgical instrument articulated joint detection tasks. The lightweight joint detection branch has been employed to efficiently locate the articulated joint position with simultaneously holding low computational cost. Moreover, the surgical instrument classification branch is introduced to boost the performance of joint detection. The two branches are merged to output the articulated joint location with respective instrument type. Extensive validation has been conducted to evaluate the proposed method. The results demonstrate promising performance of our proposed method. The work represents the feasibility to perform real-time surgical instrument articulated joint detection by taking advantage of the components of surgical robot system, contributing to the reference for further surgical intelligence.


Assuntos
Procedimentos Cirúrgicos Robóticos , Robótica , Humanos , Redes Neurais de Computação , Procedimentos Cirúrgicos Robóticos/métodos , Instrumentos Cirúrgicos
13.
J Colloid Interface Sci ; 607(Pt 2): 1908-1918, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34798707

RESUMO

The utilization of mechanical energy to control water pollutants under dark conditions is currently a point of study focus. Herein, biochar -zinc oxide (BC-ZnO) composites with various structures were synthesized by co-pyrolysis of cotton and ZnO at different temperature and used for tribo-catalytic reaction. The introduction of BC can improve charge transmission and separation efficiency. Ultraviolet photoelectron spectra (UPS) and density functional theory (DFT) calculation prove the addition of BC can reduce work function of ZnO, and enhance its electron-donating ability. Specially, suitable adsorption amount is the key factor to improve the tribo-catalytic performance. When the pyrolysis temperature is 600 °C, BC-ZnO has the best degradation efficiency, which can degrade 90% Rhodamine B (RhB) in 75 min, while ZnO can degrade only 38%. On this basis, using bovine serum albumin (BSA) as a model, the effect of tribo-catalytic reaction on controlling proteins in water was studied by fluorescence excitation-emission matrix spectroscopy (3D EEM) and infrared microscope, and the transformation of proteins was further analyzed. This study provides a new strategy to improve the tribo-catalytic performance of ZnO, and explores its application prospects of biological wastewater control.


Assuntos
Poluentes Químicos da Água , Óxido de Zinco , Adsorção , Catálise , Carvão Vegetal
14.
Sensors (Basel) ; 21(23)2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34884149

RESUMO

Non-invasive positive pressure ventilation has attracted increasing attention for air management in general anesthesia. This work proposes a novel robot equipped with two snake arms and a mask-fastening mechanism to facilitate trachea airway management for anesthesia as well as deep sedation and to improve surgical outcomes. The two snake arms with supporting terminals have been designed to lift a patient's jaw with design optimization, and the mask-fastening mechanism has been utilized to fasten the mask onto a patient's face. The control unit has been developed to implement lifting and fastening force control with safety and robustness. Loading experiments on the snake arm and tension experiments on the mask-fastening mechanism have been performed to investigate and validate the performances of the proposed anesthesia airway management robot. Experiments on a mock person have also been employed to further verify the effectiveness and reliability of the developed robot system. As an early study of an anesthesia airway management robot, it was verified as a valid attempt to perform mask non-invasive positive pressure ventilation technology by taking advantage of a robotic system.


Assuntos
Anestesia , Robótica , Manuseio das Vias Aéreas , Humanos , Reprodutibilidade dos Testes
15.
Phys Rev Lett ; 127(5): 058001, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34397240

RESUMO

We report observations of nanosecond nonuniform colloidal dynamics in a free flowing liquid jet using ultrafast x-ray speckle visibility spectroscopy. Utilizing a nanosecond double-bunch mode, the Linac Coherent Light Source free electron laser produced pairs of femtosecond coherent hard x-ray pulses. By exploring anisotropy in the visibility of summed speckle patterns which relates to the correlation functions, we evaluate not only the average particle flow rate in a colloidal nanoparticle jet, but also the nonuniform flow field within. The methodology presented here establishes the foundation for the study of nano- and atomic-scale inhomogeneous fluctuations in complex matter using x-ray free electron laser sources.

16.
Acta Crystallogr C Struct Chem ; 77(Pt 6): 291-298, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34089253

RESUMO

Multidentate carboxylate ligands have been widely used in the construction of metal-organic frameworks (MOFs) owing to the rich variety of their coordination modes, which can lead to crystalline products with interesting structures and properties. Two new main-group MOFs, namely, poly[[di-µ-aqua-diaqua(dimethylformamide)[µ7-5,5'-methylenebis(2,4,6-trimethylbenzene-1,3-dicarboxylato)]dibarium(II)] trihydrate], {[Ba2(C23H20O8)(C3H7NO)(H2O)4]·3H2O}n or {[Ba2(BTMIPA)(DMF)(H2O)4]·3H2O}n (1), and poly[[diaqua[µ6-5,5'-methylenebis(2,4,6-trimethylbenzene-1,3-dicarboxylato)]dilead(II)] 2.5-hydrate], {[Pb2(C23H20O8)(H2O)2]·2.5H2O}n or {[Pb2(BTMIPA)(H2O)2]·2.5H2O}n (2), were prepared by the self-assembly of metal salts with the semi-rigid tetracarboxylic acid ligand 5,5'-methylenebis(2,4,6-trimethylisophthalic acid) (H4BTMIPA). Both structures were characterized by elemental analysis (EA), single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), IR spectroscopy and thermogravimetric analysis (TGA). Complex 1 reveals a three-dimensional (3D) flu network formed via bridging tetranuclear secondary building units (SBUs) and complex 2 displays a 3D framework with an sqp topology based on one-dimensional metal chains. The BTMIPA4- ligands adopt a rare coordination mode in 2, although the ligands in both 1 and 2 are X-shaped. The luminescence properties of both complexes were investigated in the solid state.

17.
J Synchrotron Radiat ; 27(Pt 6): 1470-1476, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33147171

RESUMO

X-ray free-electron lasers (X-FELs) present new opportunities to study ultrafast lattice dynamics in complex materials. While the unprecedented source brilliance enables high fidelity measurement of structural dynamics, it also raises experimental challenges related to the understanding and control of beam-induced irreversible structural changes in samples that can ultimately impact the interpretation of experimental results. This is also important for designing reliable high performance X-ray optical components. In this work, X-FEL beam-induced lattice alterations are investigated by measuring the shot-to-shot evolution of near-Bragg coherent scattering from a single crystalline germanium sample. It is shown that X-ray photon correlation analysis of sequential speckle patterns measurements can be used to monitor the nature and extent of lattice rearrangements. Abrupt, irreversible changes are observed following intermittent high-fluence monochromatic X-ray pulses, thus revealing the existence of a threshold response to X-FEL pulse intensity.

18.
Technol Cancer Res Treat ; 19: 1533033820957022, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32912078

RESUMO

BACKGROUND: Doxorubicin (DOX) has antitumor effects mediated by cell viability inhibition and by inducing cellular apoptosis. However, it has limited use in clinical applications due to various factors such as hydrophobicity, dose-dependent toxicity effects on normal tissues, short cycle retention time, and low targeting ability. This study aims at enhancing hydrophilicity of DOX to restrict its toxic effects to within or around the tumor sites and also to improve its targeting ability to enhance antitumor efficiency. METHODS: Micelles composed of biodegradable poly (ethylene glycol)-poly (lactic acid) copolymers (PEG-PLA) were employed to deliver DOX via a self-assembly method and were coupled to VEGF antibodies. The morphology, size, and physical stability of PEG-PLA-DOX targeting VEGF micelles (VEGF-PEG-PLA-DOX micelles) were assessed. Then, the release ability of DOX from these micelles was monitored, and their drug loading capacity was calculated. MTT assay revealed the in vitro antitumor effect of VEGF-PEG-PLA-DOX micelles. Moreover, ROS release was measured to evaluate apoptotic effects of these nanoparticle micelles. In vivo therapeutic efficiencies of VEGF-PEG-PLA-DOX micelles on a lung cancer nude mouse model was evaluated. RESULTS: DOX-loaded micelles were obtained with a drug loading capacity of 12.2% and were monodisperse with 220 nm average diameter and a controlled in vitro DOX release for extended periods. In addition, VEGF-PEG-PLA-DOX micelles displayed a larger cell viability inhibitory effect as measured via MTT assays and greater cell apoptosis induction through in vitro ROS levels compared with PEG-PLA-DOX micelles or free DOX. Furthermore, VEGF-PEG-PLA-DOX micelles could improve in vivo antitumor effects of DOX by reducing tumor volume and weight. CONCLUSIONS: VEGF-PEG-PLA-DOX micelles displayed a larger anti-tumor effect both in in vitro A549 cells and in an in vivo lung cancer nude mouse model compared with PEG-PLA-DOX micelles or free DOX, and hence they have potential clinical applications in human lung cancer therapy.


Assuntos
Antineoplásicos/farmacologia , Doxorrubicina/farmacologia , Portadores de Fármacos/farmacologia , Lactatos/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Polietilenoglicóis/farmacologia , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Células A549 , Animais , Anticorpos/imunologia , Anticorpos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Micelas , Fator A de Crescimento do Endotélio Vascular/imunologia
19.
Int J Comput Assist Radiol Surg ; 15(12): 2061-2069, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32808149

RESUMO

PURPOSE: The knowledge of laparoscope vision can greatly improve the surgical operation room (OR) efficiency. For the vision-based computer-assisted surgery, the hand-eye calibration establishes the coordinate relationship between laparoscope and robot slave arm. While significant advances have been made for hand-eye calibration in recent years, efficient algorithm for minimally invasive surgical robot is still a major challenge. Removing the external calibration object in abdominal environment to estimate the hand-eye transformation is still a critical problem. METHODS: We propose a novel hand-eye calibration algorithm to tackle the problem which relies purely on surgical instrument already in the operating scenario for robot-assisted minimally invasive surgery (RMIS). Our model is formed by the geometry information of the surgical instrument and the remote center-of-motion (RCM) constraint. We also enhance the algorithm with stereo laparoscope model. RESULTS: Promising validation of synthetic simulation and experimental surgical robot system have been conducted to evaluate the proposed method. We report results that the proposed method can exhibit the hand-eye calibration without calibration object. CONCLUSION: Vision-based hand-eye calibration is developed. We demonstrate the feasibility to perform hand-eye calibration by taking advantage of the components of surgical robot system, leading to the efficiency of surgical OR.


Assuntos
Abdome/cirurgia , Laparoscópios , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Algoritmos , Calibragem , Mãos , Humanos , Movimento (Física)
20.
Opt Lett ; 45(7): 2086-2089, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32236074

RESUMO

We present the design and analysis of a hard x-ray split-delay optical arrangement that combines diffractive and crystal optics. Transmission gratings are employed to achieve the much-desired amplitude splitting and recombination of the beam. Asymmetric channel-cut crystals are utilized to tune the relative delay time. The use of a dispersion-compensation arrangement of the crystals allows the system to achieve subnanoradian pointing stability during a delay scan. It also minimizes wavefront distortion and preserves the pulse front and pulse duration. We analyze the performance of a prototype design that can cover a delay time range of 15 ps with a sub-20 fs time resolution at 10 keV. We anticipate that this system can fully satisfy the very demanding stability requirements for performing split-pulse x-ray photon correlation spectroscopy measurements for the investigation of fast atomic scale dynamics in complex disordered matter.

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