Magnetic resonance imaging (MRI) is an important medical imaging method, whose major limitation is its long scan time due to the imaging mechanism, increasing patients' cost and waiting time for the examination. Currently, parallel imaging (PI) and compress sensing (CS) together with other reconstruction technologies have been proposed to accelerate image acquisition. However, the image quality of PI and CS depends on the image reconstruction algorithms, which is far from satisfying in respect to both the image quality and the reconstruction speed. In recent years, image reconstruction based on generative adversarial network (GAN) has become a research hotspot in the field of magnetic resonance imaging because of its excellent performance. In this review, we summarized the recent development of application of GAN in MRI reconstruction in both single- and multi-modality acceleration, hoping to provide a useful reference for interested researchers. In addition, we analyzed the characteristics and limitations of existing technologies and forecasted some development trends in this field.
Humans ; Acceleration ; Algorithms ; Magnetic Resonance Imaging ; Technology

A protective device was designed that can be worn on the elderly, which consists of protective airbag, control box and protective mechanism. The combined acceleration, combined angular velocity and human posture angle are selected as the parameters to determine the fall, and the threshold algorithm and SVM algorithm are used to detect the fall. The protective mechanism is an inflatable device based on CO₂ compressed air cylinder, and the equal-width cam structure is applied to its transmission part to improve the puncture efficiency of the compressed gas cylinder. A fall experiment was designed to obtain the combined acceleration and angular velocity eigenvalues of fall actions (forward fall, backward fall and lateral fall) and daily activities (sitting-standing, walking, jogging and walking up and down stairs), showing that the specificity and sensitivity of the protection module reached 92.1% and 84.4% respectively, which verified the feasibility of the fall protection device.
Humans ; Aged ; Monitoring, Ambulatory ; Activities of Daily Living ; Wearable Electronic Devices ; Walking ; Acceleration ; Algorithms

Accompanied by changes in modern work and lifestyle, the incidence of cervical spondylosis has increased year by year. In view of the fact long-term fixed posture of the head and neck is one of the main causes of cervical spondylosis, a set of wearable cervical spondylosis prevention system is developed. The system comprises a head and neck movement collection module based on the acceleration sensor and a head and neck motion recognition module based on artificial intelligence. Experimental results showed that the system can accurately identify long-term posture of the head and neck, and guide users to complete effective exercise therapy under the supervision of motion recognition module. Using this system can be beneficial for the prevention of cervical spondylosis.
Acceleration ; Artificial Intelligence ; Cervical Vertebrae ; Exercise Therapy/instrumentation* ; Humans ; Movement ; Neck ; Posture ; Spondylosis/prevention & control* ; Treatment Outcome ; Wearable Electronic Devices

Immune checkpoint blockade targeting PD-1 and PD-L1 has resulted in unprecedented clinical benefit for cancer patients. Anti-PD-1/PD-L1 therapy has become the standard treatment for diverse cancer types as monotherapy or in combination with other anti-cancer therapies, and its indications are expanding. However, many patients do not benefit from anti-PD-1/PD-L1 therapy due to primary and/or acquired resistance, which is a major obstacle to broadening the clinical applicability of anti-PD-1/PD-L1 therapy. In addition, hyperprogressive disease, an acceleration of tumor growth following anti-PD-1/PD-L1 therapy, has been proposed as a new response pattern associated with deleterious prognosis. Anti-PD-1/PD-L1 therapy can also cause a unique pattern of adverse events termed immune-related adverse events, sometimes leading to treatment discontinuation and fatal outcomes. Investigations have been carried out to predict and monitor treatment outcomes using peripheral blood as an alternative to tissue biopsy. This review summarizes recent studies utilizing peripheral blood immune cells to predict various outcomes in cancer patients treated with anti-PD-1/PD-L1 therapy.
Acceleration ; Antigens, CD274 ; Biomarkers ; Biopsy ; Drug-Related Side Effects and Adverse Reactions ; Fatal Outcome ; Humans ; Prognosis ; Programmed Cell Death 1 Receptor

In order to reduce the impact caused by the contact between the foot and the ground when wearing the lower extremity exoskeleton under the condition of high load, this paper proposed an exoskeleton foot mechanism for improving the foot comfort, and optimized the key index of its influence on the comfort. Firstly, the physical model of foot mechanism was established based on the characteristics of foot stress in gait period, and then the mathematical model of vibration was abstracted. The correctness of the model was verified by the finite element analysis software ANSYS. Then, this paper analyzed the influence of vibration parameters on absolute transmissibility based on vibration mathematical model, and optimized vibration parameters with MATLAB genetic algorithm toolbox. Finally, this paper took white noise to simulate the road elevation as the vibration input, and used the visual simulation tool Simulink in MATLAB and the vibration equation to construct the acceleration simulation model, and then calculated the vibration weighted root mean square acceleration value of the foot. The results of this study show that this foot comfort mechanism can meet the comfort indexes of vibration absorption and plantar pressure, and this paper provides a relatively complete method for the design of exoskeleton foot mechanism, which has reference significance for the design of other exoskeleton foot and ankle joint rehabilitation mechanism.
Acceleration ; Ankle Joint ; Biomechanical Phenomena ; Exoskeleton Device ; Finite Element Analysis ; Foot ; Gait ; Humans ; Lower Extremity ; Models, Theoretical ; Vibration

acceleration factors of 2 and 3 (SMS2-DWI and SMS3-DWI, respectively) using a 3T scanner. Acquisition times of the three DWI sequences were measured. Image quality in the three DWI sequences was reviewed by two independent radiologists using a 4-point Likert scale and subsequently compared using the Friedman test. Apparent diffusion coefficient (ADC) values for rectal cancer and the normal rectal wall were compared among the three sequences using repeated measures analysis of variance.RESULTS: Acquisition times using C-DWI, SMS2-DWI, and SMS3-DWI were 173 seconds, 107 seconds, (38.2% shorter than C-DWI), and 77 seconds (55.5% shorter than C-DWI), respectively. For all image quality parameters other than distortion (margin sharpness, artifact, lesion conspicuity, and overall image quality), C-DWI and SMS2-DWI yielded better results than did SMS3-DWI (Ps < 0.001), with no significant differences observed between C-DWI and SMS2-DWI (Ps ≥ 0.054). ADC values of rectal cancer (p = 0.943) and normal rectal wall (p = 0.360) were not significantly different among C-DWI, SMS2-DWI, and SMS3-DWI.CONCLUSION: SMS-DWI using an acceleration factor of 2 is feasible for rectal MRI resulting in substantial reductions in acquisition time while maintaining diagnostic image quality and similar ADC values to those of C-DWI.]]>
Acceleration ; Artifacts ; Diffusion ; Humans ; Magnetic Resonance Imaging ; Rectal Neoplasms ; Rectum

Role of growth hormone (GH) in mammalian aging is actively explored in clinical, epidemiological, and experimental studies. The age-related decline in GH levels is variously interpreted as a symptom of neuroendocrine aging, as one of causes of altered body composition and other unwelcome symptoms of aging, or as a mechanism of natural protection from cancer and other chronic diseases. Absence of GH signals due to mutations affecting anterior pituitary development, GH secretion, or GH receptors produces an impressive extension of longevity in laboratory mice. Extension of healthspan in these animals and analysis of survival curves suggest that in the absence of GH, aging is slowed down or delayed. The corresponding endocrine syndromes in the human have no consistent impact on longevity, but are associated with remarkable protection from age-related disease. Moreover, survival to extremely old age has been associated with reduced somatotropic (GH and insulin-like growth factor-1) signaling in women and men. In both humans and mice, elevation of GH levels into the supranormal (pathological) range is associated with increased disease risks and reduced life expectancy likely representing acceleration of aging. The widely advertised potential of GH as an anti-aging agent attracted much interest. However, results obtained thus far have been disappointing with few documented benefits and many troublesome side effects. Possible utility of GH in the treatment of sarcopenia and frailty remains to be explored.
Acceleration ; Aging* ; Animals ; Body Composition ; Chronic Disease ; Female ; Growth Hormone* ; Humans ; Life Expectancy ; Longevity ; Male ; Mice ; Sarcopenia

OBJECTIVES: The sensitivity and positive predictive value of widely used intraoperative neuromonitoring (IONM) using electromyography (EMG) of the vocalis muscle in thyroid surgery are controversial. Thus, we developed a novel IONM system with an accelerometer sensor that uses the piezoelectric effect instead of EMG to detect laryngeal twitching. The objective of this study was to evaluate the feasibility and safety of this novel IONM system during thyroid surgery in a porcine model. METHODS: We developed an accelerometer sensor that uses the piezoelectric effect to measure laryngeal twitching in three dimensions. This novel accelerometer sensor was placed in the anterior neck skin (transcutaneous) or postcricoid area. Stimulus thresholds, amplitude, and latency of laryngeal twitching measured using the accelerometer sensor were compared to those measured through EMG of the vocalis muscle. RESULTS: The amplitudes of the accelerometer sensor at the anterior neck and postcricoid area were significantly lower than those of EMG because of differences in the measurement method used to evaluate laryngeal movement. However, no significant differences in stimulus thresholds between the EMG endotracheal tube and transcutaneous or postcricoid accelerometer sensors were observed. CONCLUSION: Accelerometer sensors located at the anterior neck or postcricoid area were able to identify laryngeal twitching. The stimulus intensity measured with these sensors was equivalent to that from conventional vocalis EMG. Our novel IONM system with an accelerometer sensor that checks changes in surface acceleration can be an alternative to EMG of the vocalis muscle for IONM in the future.
Acceleration ; Electromyography ; Laryngeal Muscles ; Methods ; Neck ; Recurrent Laryngeal Nerve ; Skin ; Thyroid Gland ; Thyroidectomy

Methylphenidate (MPH) is the most preferred drug for treatment of the attention deficit hyperactivity disorder (ADHD). Here, we aimed to discuss the possible effects and mechanisms of MPH on precocious puberty (PP) via a case series with seven children who had normal body mass index. In this case series we evaluated seven children with ADHD, who had received MPH for at least 6 months (0.5 mg/kg/dose three times a day, maximum 60 mg) and admitted to Department of Pediatric Endocrinology with PP symptoms. The mean age was 8.16 years. Basal hormonal levels (luteinizing hormone [LH], follicle stimulating hormone, and estrogen/testosterone) were within normal range. Results of LH-releasing hormone stimulation tests demonstrated central pubertal responses. Glutamine, dopamine and noradrenaline are most important excitatory neurotransmitters that have a role at the beginning of puberty. The effect of MPH, cumulating dopamine and noradrenaline in the synaptic gap could be associated with the acceleration of puberty with the excitatory effect of dopamine’s gonadotropin-releasing hormone (GnRH) release, excitatory effect of noradrenaline’s GnRH release and the disappearance of GnRH receptor expression suppressor effect on prolactin disinhibitory effect.
Acceleration ; Adolescent ; Attention Deficit Disorder with Hyperactivity ; Body Mass Index ; Child ; Dopamine ; Endocrinology ; Follicle Stimulating Hormone ; Glutamine ; Gonadotropin-Releasing Hormone ; Humans ; Methylphenidate ; Neurotransmitter Agents ; Norepinephrine ; Prolactin ; Puberty ; Puberty, Precocious ; Receptors, LHRH ; Reference Values

OBJECTIVES: In this paper, we present an efficient method to visualize computed tomography (CT) datasets using ambient occlusion, which is a global illumination technique that adds depth cues to the output image. We can change the transfer function (TF) for volume rendering and generate output images in real time. METHODS: In preprocessing, the mean and standard deviation of each local vicinity are calculated. During rendering, the ambient light intensity is calculated. The calculation is accelerated on the assumption that the CT value of the local vicinity of each point follows the normal distribution. We approximate complex TF forms with a smaller number of connected line segments to achieve additional acceleration. Ambient occlusion is combined with the existing local illumination technique to produce images with depth in real time. RESULTS: We tested the proposed method on various CT datasets using hand-drawn TFs. The proposed method enabled real-time rendering that was approximately 40 times faster than the previous method. As a result of comparing the output image quality with that of the conventional method, the average signal-to-noise ratio was approximately 40 dB, and the image quality did not significantly deteriorate. CONCLUSIONS: When rendering CT images with various TFs, the proposed method generated depth-sensing images in real time.
Acceleration ; Computer Systems ; Cues ; Dataset ; Lighting ; Mathematical Computing ; Methods ; Signal-To-Noise Ratio