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1.
Sci Rep ; 14(1): 7909, 2024 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-38575582

RESUMO

This retrospective study aimed to investigate the impact of lumbar disc herniation (LDH) on vertebral axial rotation (VAR) in the lumbar spine, focusing on both close and distant neighboring vertebrae. A total of 516 patients with LDH and an equal number of healthy individuals were included in the study, matched for age and gender. The degree of axial rotation for each lumbar spine vertebra was assessed using the Nash-Moe index. The results revealed that the prevalence of VAR in the lumbar spine was significantly higher in the LDH group compared to the Control group (65.7% vs 46.7%, P < 0.001). Among the LDH group, the L2 vertebra had the highest frequency of VAR (49.5%), followed by L1 (45.1%), and then L3 to L5 (33.6%, 8.9%, 3.1%, respectively). A similar pattern was observed in the Control group (L2, 39.8%; L1, 34.6%; L3, 23.2%; L4, 3.1%; L5, 0.8%). Furthermore, the study found that disc herniation was associated with a higher incidence of VAR not only in close neighboring vertebrae but also in distant neighboring vertebrae. This indicates that the biomechanical influence of LDH extends beyond just the immediate adjacent vertebrae. To identify potential risk factors for VAR in LDH patients, multivariate analysis was performed. The results revealed that age was an independent risk factor for VAR (OR 1.022, 95% CI [1.011, 1.034], P < 0.001). However, the duration of symptoms and presence of back pain were not found to be significant risk factors for VAR.


Assuntos
Deslocamento do Disco Intervertebral , Humanos , Deslocamento do Disco Intervertebral/epidemiologia , Estudos Retrospectivos , Rotação , Prevalência , Vértebras Lombares/diagnóstico por imagem , Fatores de Risco , Fenômenos Biomecânicos
2.
Biomed Microdevices ; 26(2): 22, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38592604

RESUMO

We report a centrifugal microfluidic device that automatically performs sample preparation under steady-state rotation for clinical applications using mass spectrometry. The autonomous microfluidic device was designed for the control of liquid operation on centrifugal hydrokinetics (CLOCK) paradigm. The reported device was highly stable, with less than 7% variation with respect to the time of each unit operation (sample extraction, mixing, and supernatant extraction) in the preparation process. An agitation mechanism with bubbling was used to mix the sample and organic solvent in this device. We confirmed that the device effectively removed the protein aggregates from the sample, and the performance was comparable to those of conventional manual sample preparation procedures that use high-speed centrifugation. In addition, probe electrospray ionization mass spectrometry (PESI-MS) was performed to compare the device-treated and manually treated samples. The obtained PESI-MS spectra were analyzed by partial least squares discriminant analysis, and the preparation capability of the device was found to be equivalent to that of the conventional method.


Assuntos
Microfluídica , Espectrometria de Massas por Ionização por Electrospray , Centrifugação , Dispositivos Lab-On-A-Chip , Rotação
3.
Sci Rep ; 14(1): 8828, 2024 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632471

RESUMO

The aim of this split-mouth randomized clinical trial was to evaluate the clinical outcomes (operative time, edema, trismus, and pain), the immediate histological effects, the alveolar repair (2 and 4 months), and the quality of life after the extraction of impacted third molars using high-speed pneumatic and electrical rotation. Sixteen patients underwent extraction of the two mandibular third molars with a minimum interval of 15 days. On one side of the participant's mouth, high-speed pneumatic rotation was used (Control Group-CG) while for the other side, high-speed electrical rotation was used (Study Group-SG). Statistical analysis included ANOVA repeated measures and Pearson correlations. SG group showed: shorter operative time (p = 0.019), less pain (p = 0.034), swelling (p < 0.001) and trismus (p = 0.025) on the 1st postoperative day; less pain (p = 0.034) and trismus (p = 0.010) on the 3rd postoperative day; less trismus (p = 0.032) on the 7th postoperative day; and better quality of life (p = 0.007). No differences were observed for peripheral bone damage or bone density of alveolar repair at 2 and 4 months between groups. Electric high-speed rotation provided better postoperative clinical parameters of pain, edema and trismus when compared with pneumatic high-speed rotation for mandibular third molar surgery.Trial registration: Brazilian Registry of Clinical Trials registration number RBR-4xyqhqm ( https://ensaiosclinicos.gov.br/rg/RBR-4xyqhqm ).


Assuntos
Dente Serotino , Trismo , Humanos , Dente Serotino/cirurgia , Rotação , Estudos Prospectivos , Qualidade de Vida , Dor Pós-Operatória , Extração Dentária , Boca , Edema
4.
Sci Rep ; 14(1): 9358, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38653758

RESUMO

The goal of this experimental study was to quantify the influence of helical pitch and gantry rotation time on image quality and file size in ultrahigh-resolution photon-counting CT (UHR-PCCT). Cervical and lumbar spine, pelvis, and upper legs of two fresh-frozen cadaveric specimens were subjected to nine dose-matched UHR-PCCT scan protocols employing a collimation of 120 × 0.2 mm with varying pitch (0.3/1.0/1.2) and rotation time (0.25/0.5/1.0 s). Image quality was analyzed independently by five radiologists and further substantiated by placing normed regions of interest to record mean signal attenuation and noise. Effective mAs, CT dose index (CTDIvol), size-specific dose estimate (SSDE), scan duration, and raw data file size were compared. Regardless of anatomical region, no significant difference was ascertained for CTDIvol (p ≥ 0.204) and SSDE (p ≥ 0.240) among protocols. While exam duration differed substantially (all p ≤ 0.016), the lowest scan time was recorded for high-pitch protocols (4.3 ± 1.0 s) and the highest for low-pitch protocols (43.6 ± 15.4 s). The combination of high helical pitch and short gantry rotation times produced the lowest perceived image quality (intraclass correlation coefficient 0.866; 95% confidence interval 0.807-0.910; p < 0.001) and highest noise. Raw data size increased with acquisition time (15.4 ± 5.0 to 235.0 ± 83.5 GByte; p ≤ 0.013). Rotation time and pitch factor have considerable influence on image quality in UHR-PCCT and must therefore be chosen deliberately for different musculoskeletal imaging tasks. In examinations with long acquisition times, raw data size increases considerably, consequently limiting clinical applicability for larger scan volumes.


Assuntos
Fótons , Humanos , Tomografia Computadorizada por Raios X/métodos , Cadáver , Rotação , Doses de Radiação , Tomografia Computadorizada Espiral/métodos
5.
Sci Rep ; 14(1): 8531, 2024 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609470

RESUMO

This study presents a thorough numerical evaluation of the crashworthiness properties of a new bio-inspired DNA tubes (BIDNATs) with circular, elliptical, and rectangular cross-sections. Deformation and crashworthiness behaviors are evaluated using axial quasi-static crushing simulations by ABAQUS/Explicit (Abaqus 6.14, https://www.3ds.com/products-services/simulia/products/abaqus/ ). The study compares the performance of conventional tubes with rectangular and elliptical cross-sections to DNA-inspired tubes. Increasing the rotation angle leads to more helices and a pronounced helix angle, resulting in lower initial peak force (IPF). However, lower cross-section aspect ratios generally have higher IPF and specific energy absorption (SEA) values. BIDNATs with rectangular cross-sections and a 540° rotation angle have the lowest SEA and IPF values across all aspect ratios. Notably, for the 110/100 aspect ratio, the SEA of E110/100 is 71% higher than the conventional tube. Overall, BIDNATs with elliptical cross-sections and a 360° rotation angle exhibit higher SEA values and lower IPF values, particularly for a width (W) of 100 mm. Conventional circular and elliptical tubes generally have SEA values exceeding 6 J/g, with only E110/100 surpassing this among DNA-inspired tubes. The NE110/100 tube has the highest SEA, surpassing E110/100 by 54%, while its IPF is 10% greater than DNA-inspired E110/100. It's worth noting that conventional circular and elliptical tubes have higher IPF values compared to their DNA-inspired counterparts. These findings offer valuable insights for engineers and researchers in the design of crash tubes to improve overall vehicle safety for both occupants and pedestrians.


Assuntos
DNA , Pedestres , Humanos , Engenharia , Pesquisadores , Rotação
6.
PLoS One ; 19(3): e0298028, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38507361

RESUMO

The bacterial flagellum is a complex structure formed by more than 25 different proteins, this appendage comprises three conserved structures: the basal body, the hook and filament. The basal body, embedded in the cell envelope, is the most complex structure and houses the export apparatus and the motor. In situ images of the flagellar motor in different species have revealed a huge diversity of structures that surround the well-conserved periplasmic components of the basal body. The identity of the proteins that form these novel structures in many cases has been elucidated genetically and biochemically, but in others they remain to be identified or characterized. In this work, we report that in the alpha proteobacteria Cereibacter sphaeroides the novel protein MotK along with MotE are essential for flagellar rotation. We show evidence that these periplasmic proteins interact with each other and with MotB2. Moreover, these proteins localize to the flagellated pole and MotK localization is dependent on MotB2 and MotA2. These results together suggest that the role of MotK and MotE is to activate or recruit the flagellar stators to the flagellar structure.


Assuntos
Proteínas de Bactérias , Proteínas Periplásmicas , Proteínas de Bactérias/metabolismo , Proteínas Periplásmicas/metabolismo , Rotação , Flagelos/metabolismo , Periplasma/metabolismo
7.
Phys Chem Chem Phys ; 26(13): 10343-10356, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38501246

RESUMO

Rhodopsins are light-responsive proteins forming two vast and evolutionary distinct superfamilies whose functions are invariably triggered by the photoisomerization of a single retinal chromophore. In 2018 a third widespread superfamily of rhodopsins called heliorhodopsins was discovered using functional metagenomics. Heliorhodopsins, with their markedly different structural features with respect to the animal and microbial superfamilies, offer an opportunity to study how evolution has manipulated the chromophore photoisomerization to achieve adaptation. One question is related to the mechanism of such a reaction and how it differs from that of animal and microbial rhodopsins. To address this question, we use hundreds of quantum-classical trajectories to simulate the spectroscopically documented picosecond light-induced dynamics of a heliorhodopsin from the archaea thermoplasmatales archaeon (TaHeR). We show that, consistently with the observations, the trajectories reveal two excited state decay channels. However, inconsistently with previous hypotheses, only one channel is associated with the -C13C14- rotation of microbial rhodopsins while the second channel is characterized by the -C11C12- rotation typical of animal rhodopsins. The fact that such -C11C12- rotation is aborted upon decay and ground state relaxation, explains why illumination of TaHeR only produces the 13-cis isomer with a low quantum efficiency. We argue that the documented lack of regioselectivity in double-bond excited state twisting motion is the result of an "adaptation" that could be completely lost via specific residue substitutions modulating the steric hindrance experienced along the isomerization motion.


Assuntos
Rodopsina , Rodopsinas Microbianas , Animais , Isomerismo , Rodopsinas Microbianas/química , Rodopsina/química , Rotação
8.
Biosensors (Basel) ; 14(3)2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38534219

RESUMO

The rotation of cells is of significant importance in various applications including bioimaging, biophysical analysis and microsurgery. Current methods usually require complicated fabrication processes. Herein, we proposed an induced charged electroosmosis (ICEO) based on a chip manipulation method for rotating cells. Under an AC electric field, symmetric ICEO flow microvortexes formed above the electrode surface can be used to trap and rotate cells. We have discussed the impact of ICEO and dielectrophoresis (DEP) under the experimental conditions. The capabilities of our method have been tested by investigating the precise rotation of yeast cells and K562 cells in a controllable manner. By adjusting the position of cells, the rotation direction can be changed based on the asymmetric ICEO microvortexes via applying a gate voltage to the gate electrode. Additionally, by applying a pulsed signal instead of a continuous signal, we can also precisely and flexibly rotate cells in a stepwise way. Our ICEO-based rotational manipulation method is an easy to use, biocompatible and low-cost technique, allowing rotation regardless of optical, magnetic or acoustic properties of the sample.


Assuntos
Eletricidade , Eletro-Osmose , Eletro-Osmose/métodos , Rotação , Eletrodos , Acústica
9.
Sensors (Basel) ; 24(6)2024 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-38544186

RESUMO

In biomechanics, movement is typically recorded by tracking the trajectories of anatomical landmarks previously marked using passive instrumentation, which entails several inconveniences. To overcome these disadvantages, researchers are exploring different markerless methods, such as pose estimation networks, to capture movement with equivalent accuracy to marker-based photogrammetry. However, pose estimation models usually only provide joint centers, which are incomplete data for calculating joint angles in all anatomical axes. Recently, marker augmentation models based on deep learning have emerged. These models transform pose estimation data into complete anatomical data. Building on this concept, this study presents three marker augmentation models of varying complexity that were compared to a photogrammetry system. The errors in anatomical landmark positions and the derived joint angles were calculated, and a statistical analysis of the errors was performed to identify the factors that most influence their magnitude. The proposed Transformer model improved upon the errors reported in the literature, yielding position errors of less than 1.5 cm for anatomical landmarks and 4.4 degrees for all seven movements evaluated. Anthropometric data did not influence the errors, while anatomical landmarks and movement influenced position errors, and model, rotation axis, and movement influenced joint angle errors.


Assuntos
Aprendizado Profundo , Movimento , Rotação , Fenômenos Biomecânicos , Fotogrametria
10.
Neural Netw ; 174: 106237, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38513508

RESUMO

Although 3D human pose estimation has recently made strides, it is still difficult to precisely recreate a 3D human posture from a single image without the aid of 3D annotation for the following reasons. Firstly, the process of reconstruction inherently suffers from ambiguity, as multiple 3D poses can be projected onto the same 2D pose. Secondly, accurately measuring camera rotation without laborious camera calibration is a difficult task. While some approaches attempt to address these issues using traditional computer vision algorithms, they are not differentiable and cannot be optimized through training. This paper introduces two modules that explicitly leverage geometry to overcome these challenges, without requiring any 3D ground-truth or camera parameters. The first module, known as the relative depth estimation module, effectively mitigates depth ambiguity by narrowing down the possible depths for each joint to only two candidates. The second module, referred to as the differentiable pose alignment module, calculates camera rotation by aligning poses from different views. The use of these geometrically interpretable modules reduces the complexity of training and yields superior performance. By adopting our proposed method, we achieve state-of-the-art results on standard benchmark datasets, surpassing other self-supervised methods and even outperforming several fully-supervised approaches that heavily rely on 3D annotations.


Assuntos
Algoritmos , Imageamento Tridimensional , Humanos , Imageamento Tridimensional/métodos , Postura , Rotação , Calibragem
11.
J Biomech ; 166: 112019, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38479149

RESUMO

A few reports on scapular motion during shoulder joint extension exist. Understanding the normal motion of shoulder joint extension may be useful in evaluating and treating patients with diminished or minimal shoulder joint extension. Therefore, this study aimed to identify scapular motion during shoulder joint extension movement in a sitting position. Shoulder joint extension movement in the sitting position were measured in 22 healthy adults (age, 25.8 ± 2.7 years). Shoulder joint extension, scapular upward rotation, anterior tilt, external rotation angles, and the acromion position were investigated using a three-dimensional motion analyzer. The difference from each value of 10° to 50° shoulder joint extension to each value of 0° shoulder joint extension were checked. The results were compared using multiple comparison method. In most participants, the scapula tilted posteriorly up to 30° of the shoulder joint extension and anteriorly after 30°. Scapular upward and external rotation continued to increase with shoulder extension. Furthermore, the acromion was displaced upward and backward. Thus, scapular posterior tilt is necessary for shoulder joint extension during the initial movement, followed by anterior tilt. The acromion may have been displaced posteriorly because of clavicular retraction, causing the scapula to tilt posteriorly. After 30° of shoulder joint extension, the scapular anterior tilt may have prevailed over the scapular posterior tilt.


Assuntos
Articulação do Ombro , Adulto , Humanos , Adulto Jovem , Fenômenos Biomecânicos , Escápula , Ombro , Movimento , Amplitude de Movimento Articular , Rotação
12.
Sci Rep ; 14(1): 6217, 2024 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-38485965

RESUMO

Switching between tasks entails costs when compared to repeating the same task. It is unclear whether switch costs also occur when repeating the same task but switching the underlying cognitive strategy (CS). Here, we investigated whether CS switch costs exist despite overlap in mental processing between CSs and a lack of abstract goal (always "solve task X") or answer key binding switches. Specifically, we asked participants to judge the identity of two misaligned objects by either mental or manual computer-mediated object rotation. In each trial of Block 1, to measure switch costs without choice-related cognitive processes, a cue indicated which CS (mental/manual) to use. In Block 2, the CS was freely chosen. Participants exhibited considerable CS switch costs for both cued and freely chosen switches. Moreover, Block 1 switch costs moderately predicted Block 2 switch frequency, while an overall tendency for CS repetition was observed. In sum, we found that switch costs are not confined to situations in which tasks are switched but generalize to situations in which the task stays identical and the CS is switched instead. The results have implications for modern computerized cognitive environments in which a multitude of cognitive strategies is available for the same task.


Assuntos
Sinais (Psicologia) , Desempenho Psicomotor , Humanos , Tempo de Reação , Rotação , Cognição
13.
Cognition ; 246: 105759, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38430752

RESUMO

A key issue in recent visual word recognition literature is whether text rotation disrupts the early stages of orthographic processing. Previous research found no masked repetition priming effect when primes were rotated ≥90° in alphabetic languages. The present study investigated the impact of text rotation using logographic (two-character Japanese kanji) words. In Experiment 1, we conducted a masked repetition priming lexical decision experiment with upright and 180° rotated primes. The rotated primes produced a significant priming effect, although the effect was smaller than the upright primes. In Experiment 2, we further examined the effectiveness of 180° rotated primes in two different conditions: the whole words were rotated vs. each constituent character was rotated at their own positions. Both prime types produced significant priming effects of similar magnitudes. These findings suggest that orthographic processing is more robust against text rotation in logographic languages than in alphabetic languages.


Assuntos
Reconhecimento Visual de Modelos , Leitura , Humanos , Rotação , Japão , Idioma , Priming de Repetição , Mascaramento Perceptivo
14.
Knee Surg Sports Traumatol Arthrosc ; 32(5): 1298-1307, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38504507

RESUMO

PURPOSE: Total knee arthroplasty (TKA), which has medial pivot and mobile-bearing mechanisms, has been developed and clinically used. However, the in vivo dynamic kinematics of the mobile medial pivot-type TKA (MMPTKA) is unclear. This study analysed the in vivo kinematics of MMPTKA in weight-bearing and nonweight-bearing conditions. METHODS: The study included 10 knees that underwent primary TKA using MMPTKA. After TKA, lateral view radiographs of the knee in full extension, 90° of flexion and passive full flexion were taken under general anaesthesia in the nonweight-bearing condition. At least 6 months postoperatively, knee motion during squatting from a weight-bearing standing position was observed using a flat-panel detector and analysed using the three-dimensional-to-two-dimensional image registration technique. RESULTS: Under anaesthesia: in passive full flexion, the anteroposterior (AP) locations of the femoral component's medial and lateral distal points were 10.2 and 16.0 mm posterior, and the rotational angles of the femoral component's X-axis (FCX) and insert were 8.1° external rotation and 18.5° internal rotation to full extension, respectively. Squatting: the AP translations of the femoral component's medial and lateral most distal points were 2.2 and 6.4 mm, and the rotational angles of the FCX and insert were 5.7° and 1.6° external rotation, respectively. Significant differences were observed in the AP translation of the femoral component's medial and lateral most distal points and changes in the insert's rotational angle when comparing under anaesthesia and squatting. CONCLUSIONS: The kinematics of the insert in MMPTKA was significantly influenced by loading and muscle contraction. The femoral component exhibited substantial external rotation and posterior translation under anaesthesia, which may contribute to achieving an optimal range of motion. The insert remained relatively stable during squatting and minimal rotation was observed, indicating good stability. MMPTKA was expected to demonstrate rational kinematics by incorporating mobile and medial pivot mechanisms. LEVEL OF EVIDENCE: Level IV, prospective biomechanical case series study.


Assuntos
Artroplastia do Joelho , Amplitude de Movimento Articular , Suporte de Carga , Humanos , Artroplastia do Joelho/métodos , Artroplastia do Joelho/instrumentação , Masculino , Feminino , Idoso , Fenômenos Biomecânicos , Pessoa de Meia-Idade , Articulação do Joelho/cirurgia , Articulação do Joelho/fisiologia , Articulação do Joelho/fisiopatologia , Prótese do Joelho , Osteoartrite do Joelho/cirurgia , Osteoartrite do Joelho/fisiopatologia , Idoso de 80 Anos ou mais , Rotação
15.
J Sports Sci ; 42(4): 365-372, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38507567

RESUMO

Patellofemoral pain syndrome (PFPS) is a common injury among runners, and it is thought that abnormal lower extremity biomechanics contribute to its development. However, the relationship between biomechanical changes after a marathon and PFPS injury remains limited. This study aims to investigate whether differences in knee and hip kinematics and lower extremity muscle activities exist in recreational runners before and after a marathon. Additionally, it aims to explore the relationship between these biomechanical changes and the development of PFPS injury. 12 recreational runners participated in the study. Kinematics and muscle activities of the lower extremity were recorded during walking (5 km/h) and running (10 km/h) tasks within 24 hours before and within 5 hours after a marathon. After the marathon, there was a significant decrease in peak knee flexion (walking: p = 0.006; running: p = 0.006) and an increase in peak hip internal rotation (walking: p = 0.026; running: p = 0.015) during the stance phase of both walking and running compared to before the marathon. The study demonstrates a decrease in knee flexion and an increase in hip internal rotation during the stance phase of gait tasks after completing a marathon, which may increase the risk of developing PFPS injury.


Assuntos
Extremidade Inferior , Corrida de Maratona , Músculo Esquelético , Síndrome da Dor Patelofemoral , Caminhada , Humanos , Fenômenos Biomecânicos , Caminhada/fisiologia , Masculino , Adulto , Músculo Esquelético/fisiologia , Extremidade Inferior/fisiologia , Feminino , Corrida de Maratona/fisiologia , Síndrome da Dor Patelofemoral/fisiopatologia , Corrida/fisiologia , Marcha/fisiologia , Articulação do Quadril/fisiologia , Quadril/fisiologia , Eletromiografia , Joelho/fisiologia , Adulto Jovem , Articulação do Joelho/fisiologia , Rotação , Estudos de Tempo e Movimento
16.
Math Biosci Eng ; 21(2): 3110-3128, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38454721

RESUMO

Carotid plaque classification from ultrasound images is crucial for predicting ischemic stroke risk. While deep learning has shown effectiveness, it heavily relies on substantial labeled datasets. Achieving high performance with limited labeled images is essential for clinical use. Self-supervised learning (SSL) offers a potential solution; however, the existing works mainly focus on constructing the SSL tasks, neglecting the use of multiple tasks for pretraining. To overcome these limitations, this study proposed a self-supervised fusion network (Fusion-SSL) for carotid plaque ultrasound image classification with limited labeled data. Fusion-SSL consists of two SSL tasks: classifying image block order (Ordering) and predicting image rotation angle (Rotating). A dual-branch residual neural network was developed to fuse feature presentations learned by the two tasks, which can extract richer visual boundary shape and contour information than a single task. In this experiment, 1270 carotid plaque ultrasound images were collected from 844 patients at Zhongnan Hospital (Wuhan, China). The results showed that Fusion-SSL outperforms single SSL methods across different percentages of labeled training data, ranging from 10 to 100%. Moreover, with only 40% labeled training data, Fusion-SSL achieved comparable results to a single SSL method (predicting image rotation angle) with 100% labeled data. These results indicate that Fusion-SSL could be beneficial for the classification of carotid plaques and the early warning of a stroke in clinical practice.


Assuntos
Hospitais , Acidente Vascular Cerebral , Humanos , China , Redes Neurais de Computação , Rotação , Acidente Vascular Cerebral/diagnóstico por imagem
17.
Opt Express ; 32(4): 5287-5300, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38439260

RESUMO

Misfolding of amyloid protein will cause neurodegeneration and trigger conformational disease. The lack of an effective detection approach is a brake on unveiling the mechanism of protein misfolding. We theoretically proposed a novel metasurface-based biosensor for characterizing the protein's conformation. The coupling complementary split ring resonator (cSRR) was engineered to manipulate incident waves in the near-infrared (NIR) and mid-infrared (MIR) windows at the same sensing surface. The cSRRs had the advantages of intensifying the electric field and sharpening the resonance profile, resulting in a highly qualified biosensing performance. In the NIR window, the biolayer's refractive index and thickness change were detected by the dual-wavelength, which resolved into an optogeometrical parameter of the amyloid biolayer. In the MIR window, the resonant wave specifically triggered the rotation-vibration transition of amyloid protein molecules with different conformations, which was shown as the unique Amide I and II bands in the fingerprint spectrum. Thus, our proposed biosensor presented sensitive detection of biolayer and specific identification of constituent molecules. It is helpful to interpret the protein's misfolding behavior on the molecular level by associating the biolayer's structure and the constituent molecule's conformational change.


Assuntos
Amidas , Proteínas Amiloidogênicas , Conformação Proteica , Eletricidade , Rotação
18.
Proc Natl Acad Sci U S A ; 121(11): e2314199121, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38451940

RESUMO

Proton-powered c-ring rotation in mitochondrial ATP synthase is crucial to convert the transmembrane protonmotive force into torque to drive the synthesis of adenosine triphosphate (ATP). Capitalizing on recent cryo-EM structures, we aim at a structural and energetic understanding of how functional directional rotation is achieved. We performed multi-microsecond atomistic simulations to determine the free energy profiles along the c-ring rotation angle before and after the arrival of a new proton. Our results reveal that rotation proceeds by dynamic sliding of the ring over the a-subunit surface, during which interactions with conserved polar residues stabilize distinct intermediates. Ordered water chains line up for a Grotthuss-type proton transfer in one of these intermediates. After proton transfer, a high barrier prevents backward rotation and an overall drop in free energy favors forward rotation, ensuring the directionality of c-ring rotation required for the thermodynamically disfavored ATP synthesis. The essential arginine of the a-subunit stabilizes the rotated configuration through a salt bridge with the c-ring. Overall, we describe a complete mechanism for the rotation step of the ATP synthase rotor, thereby illuminating a process critical to all life at atomic resolution.


Assuntos
ATPases Mitocondriais Próton-Translocadoras , Prótons , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Conformação Proteica , Trifosfato de Adenosina , Rotação , ATPases Translocadoras de Prótons/metabolismo
19.
Artigo em Inglês | MEDLINE | ID: mdl-38522875

RESUMO

En bloc rotation of the outflow tracts or double root translocation offers an anatomic repair of transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction and closely related forms of double outlet right ventricle. The technical principle is to excise aortic and pulmonary root en bloc, rotate them as a whole by 180°, and reimplant them. The left ventricular outflow tract is enlarged with the patch closing the ventricular septal defect. In our experience, two thirds of the pulmonary valves could be preserved. Growth of the aortic and pulmonary root could be demonstrated in several studies performed by our group. It is still a complex and technically demanding procedure with long cardiopulmonary bypass periods and cross-clamp times. However, perioperative mortality and complications do not differ significantly from other forms of reconstruction. The reoperation rate is significantly lower. Presently, the best time to perform this operation seems to be after the newborn period within the first year of life.


Assuntos
Dupla Via de Saída do Ventrículo Direito , Comunicação Interventricular , Transposição dos Grandes Vasos , Recém-Nascido , Humanos , Lactente , Transposição dos Grandes Vasos/cirurgia , Transposição dos Grandes Vasos/complicações , Resultado do Tratamento , Rotação , Dupla Via de Saída do Ventrículo Direito/complicações , Dupla Via de Saída do Ventrículo Direito/cirurgia , Comunicação Interventricular/cirurgia
20.
IEEE Trans Vis Comput Graph ; 30(5): 2624-2632, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38446650

RESUMO

Humans perceive the world by integrating multimodal sensory feedback, including visual and auditory stimuli, which holds true in virtual reality (VR) environments. Proper synchronization of these stimuli is crucial for perceiving a coherent and immersive VR experience. In this work, we focus on the interplay between audio and vision during localization tasks involving natural head-body rotations. We explore the impact of audio-visual offsets and rotation velocities on users' directional localization acuity for various viewing modes. Using psychometric functions, we model perceptual disparities between visual and auditory cues and determine offset detection thresholds. Our findings reveal that target localization accuracy is affected by perceptual audio-visual disparities during head-body rotations, but remains consistent in the absence of stimuli-head relative motion. We then showcase the effectiveness of our approach in predicting and enhancing users' localization accuracy within realistic VR gaming applications. To provide additional support for our findings, we implement a natural VR game wherein we apply a compensatory audio-visual offset derived from our measured psychometric functions. As a result, we demonstrate a substantial improvement of up to 40% in participants' target localization accuracy. We additionally provide guidelines for content creation to ensure coherent and seamless VR experiences.


Assuntos
Percepção Espacial , Realidade Virtual , Humanos , Masculino , Adulto , Feminino , Percepção Espacial/fisiologia , Adulto Jovem , Gráficos por Computador , Percepção Auditiva/fisiologia , Rotação , Percepção Visual/fisiologia , Movimentos da Cabeça/fisiologia , Interface Usuário-Computador
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