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91.
Jagoe Charles H. Dallas Cham E. Chesser Ronald K. Smith Michael H. Lingenfelser Susan K. Lingenfelser J.T. Holloman Kevin Lomakin Michael 《Ecotoxicology (London, England)》1998,7(4):201-209
Samples of fish and sediments collected from waters within 10 km of the Chernobyl Nuclear Power Plant were analysed for radiocaesium and other atmospherically transported pollutants (lead (Pb) and mercury (Hg)) were measured in fish tissues. For comparison, fish muscle was also sampled from a less-contaminated area of the Kiev Reservoir and from a hatchery in Kiev. In sediments, 137Cs was the major gamma-emitting isotope, with concentrations of over 100 Bq g–1 in canals adjacent to the reactor and in ponds that were downwind during the accident. The radiocaesium distributions appeared non-normal, were very patchy and could vary by over 100% in samples collected metres to tens of metres apart. Fish muscle radiocaesium from ponds within 10 km of the power plant was in the range of 6–192 Bq g–1. The fish muscle radiocaesium concentrations were highest in ponds from the downwind sites and were correlated with the sediment radiocaesium concentrations. The lead and mercury concentrations in fish were relatively low (medians <0.8 g Hg per g dry mass and <150 ng Pb per g dry mass), suggesting little contamination from lead applied to the burning reactor after the accident. The radiocaesium levels in fish in areas close to the reactor continue to be high enough to cause health concerns to humans that might utilize these resources. 相似文献
92.
New dynamic particle image velocimetry (PIV) technology was applied to the study of the flow field associated with prosthetic
heart valves. Four bileaflet prostheses, the St. Jude Medical (SJM) valve, the On-X valve with straight leaflets, the Jyros
(JR) valve, and the Edwards MIRA (MIRA) valve with curved leaflets, were tested in the mitral position under pulsatile flow
conditions to find the effect of the leaflet shape and overall valve design on the flow field, particularly in terms of the
turbulent stress distribution, which may influence hemolysis, platelet activation, and thrombus formation. Comparison of the
time-resolved flow fields associated with the opening, accelerating, peak, and closing phases of the diastolic flow revealed
the effects of the leaflet shape and overall valve design on the flow field. Anatomically and antianatomically oriented bileaflet
valves were also compared in the mitral position to study the effects of the orientation on the downstream flow field. The
experimental program used a dynamic PIV system utilizing a high-speed, high-resolution video camera to map the true time-resolved
velocity field inside the simulated ventricle. Based on the experimental data, the following general conclusions can be made.
High-resolution dynamic PIV can capture true chronological changes in the velocity and turbulence fields. In the vertical
measuring plane that passes the centers of both the aortic and mitral valves (A-A section), bileaflet valves show clear and
simple circulatory flow patterns when the valve is installed in the antianatomical orientation. The SJM, the On-X, and the
MIRA valves maintain a relatively high velocity through the central orifice. The curved leaflets of the JR valve generate
higher velocities with a divergent flow during the accelerating and peak flow phases when the valve is installed in the anatomical
orientation. In the velocity field directly below the mitral valve and normal to the previous measuring plane (B-B section),
where characteristic differences in valve design on the three-dimensional flow should be visible, the symmetrical divergent
nature of the flow generated by the two inclined half-disks installed in the antianatomical orientation was evident. The SJM
valve, with a central downward flow near the valve, is contrasted with the JR valve, which has a peripherally strong downward
circulation with higher turbulent stresses. The On-X valve has a strong central downward flow attributable to its large opening
angle and flared inlet shape. The MIRA valve also has a relatively strong downward central flow. The MIRA valve, however,
diverts the flow three-dimensionally due to its peripherally curved leaflets. 相似文献
93.
Terence Ng Shu Mei Teo Hui Ling Yeo Maung Shwe Yan Xiang Gan Yin Ting Cheung Koon Mian Foo Mooi Tai Cham Jung Ah Lee Yee Pin Tan Gilbert Fan Wei Sean Yong Madhukumar Preetha Wei-Jen Kiley Loh Si-Lin Koo Amit Jain Guek Eng Lee Mabel Wong Rebecca Dent Yoon Sim Yap Raymond Ng Chiea Chuen Khor Han Kiat Ho Alexandre Chan 《Neuro-oncology》2016,18(2):244-251
Background
Brain-derived neurotrophic factor (BDNF), a neurotrophin that regulates neuronal function and development, is implicated in several neurodegenerative conditions. Preliminary data suggest that a reduction of BDNF concentrations may lead to postchemotherapy cognitive impairment. We hypothesized that a single nucleotide polymorphism (rs6265) of the BDNF gene may predispose patients to cognitive impairment. This study aimed to evaluate the effect of BDNF gene polymorphism on chemotherapy-associated cognitive impairment.Methods
Overall, 145 patients receiving chemotherapy for early-stage breast cancer (mean age: 50.8 ± 8.8 y; 82.1% Chinese) were recruited. Patients'' cognitive functions were assessed longitudinally using the validated Functional Assessment of Cancer Therapy–Cognitive Function (v.3) and an objective computerized tool, Headminder. Genotyping was performed using Sanger sequencing. Logistic regression was used to evaluate the association between BDNF Val66Met polymorphism and cognition after adjusting for ethnicity and clinically important covariates.Results
Of the 145 patients, 54 (37%) reported cognitive impairment postchemotherapy. The Met/Met genotype was associated with statistically significant lower odds of developing cognitive impairment (odds ratio [OR] = 0.26; 95% CI: 0.08–0.92; P = .036). The Met carriers were less likely to experience impairment in the domains of verbal fluency (OR = 0.34; 95% CI: 0.12–0.90; P = .031) and multitasking ability (OR = 0.37; 95% CI: 0.15–0.91; P = .030) compared with the Val/Val homozygote. No associations were observed between Headminder and the BDNF Val66Met polymorphism.Conclusions
This is the first study to provide evidence that carriers of the BDNF Met allele are protected against chemotherapy-associated cognitive impairment. Further studies are required to validate the findings. 相似文献94.
Weinsaft JW Cham MD Janik M Min JK Henschke CI Yankelevitz DF Devereux RB 《International journal of cardiology》2008,126(3):359-365
95.
Wei Lv PhD Tao Chen ME Yifan Zeng BE Weihong Liu BE Chuying Huang BE 《Journal of Cosmetic Dermatology》2023,22(9):2565-2578
Background
Deep-learning object detection has been applied in various industries, including healthcare, to address hair loss.Methods
In this paper, YOLOv5 object detection algorithm was used to detect hair follicles in a small and specific image dataset collected using a specialized camera on the scalp of individuals with different ages, regions, and genders. The performance of YOLOv5 was compared with other popular object detection models.Results
YOLOv5 performed well in the detection of hair follicles, and the follicles were classified into five classes based on the number of hairs and the type of hair contained. In single-class object detection experiments, a smaller batch size and the smallest YOLOv5s model achieved the best results, with an map of 0.8151. In multiclass object detection experiments, the larger YOLOv5l model was able to achieve the best results, and batch size affected the result of model training.Conclusion
YOLOv5 is a promising algorithm for detecting hair follicles in a small and specific image dataset, and its performance is comparable to other popular object detection models. However, the challenges of small-scale data and sample imbalance need to be addressed to improve the performance of target detection algorithms. 相似文献96.
Yongheon Kim BE Hyunseon Yu MS Sunghwan An MD Donghoon Ha BE Byungjo Jung PhD 《Journal of Cosmetic Dermatology》2023,22(11):2982-2988
Objective
Although focused ultrasound modalities have achieved positive clinical results in noninvasive skin rejuvenation, they presented various side effects and particularly severe pain during treatment. This study introduces a microfocused ultrasound (MFU) device, ULTIGHT, to overcome the severe pain issue, providing quasi-facial lifting.Materials and Methods
Transducer surface was imaged with a scanning electron microscope. The energies of four treatment cartridges were measured using an ultrasound power meter. In vitro experiments were performed to quantitatively evaluate the MFU thermal zones (MFUTZs) and treatment line (TL) of 10 MFUTZs. Ex vivo experiments were performed to evaluate the MFUTZs and temperature rise in tissue. Clinical trials using eight volunteers were performed to qualitatively evaluate facial lifting.Results
The MFU transducer clearly showed a smooth and no air gap surface. ULTIGHT produced 10 discrete MFUTZs in a TL of length 10 mm. In ex vivo tissue, discrete linear MFUTZs were clearly observed at lower number of TLs; however, they started to aggregate at higher number of TLs. The temperature rise was linearly increased as a function of the number of treatments. A single MFUTZ resulted in a temperature rise of 3°C–10°C that could cause hyperthermia for body temperature. In the clinical trials, the volunteers showed quasi-facial lifting right after treatment on the lower facial region.Conclusions
ULTIGHT provides relatively low energy, which may be advantageous or disadvantageous depending on clinical applications. Additionally, it has the advantage of being pain-free even without anesthetic during treatment, providing quasi-facial lifting right after treatment. 相似文献97.
98.
Role of nitric oxide in regulation of coronary blood flow during myocardial ischemia in dogs 总被引:6,自引:0,他引:6
Masafumi Kitakaze Md Koichi Node MD Tetsuo Minamino MD Hiroaki Kosaka MD Yoshiro Shinozaki BE Hidezo Mori MD Michitoshi Inoue MD Masatsugu Hori MD Takenobu Kamada MD 《Journal of the American College of Cardiology》1996,27(7):1804-1812
Objectives. This study was undertaken to examine whether nitric oxide released in ischemic myocardium decreases the coronary vascular resistance and attenuates the severity of contractile and metabolic dysfunction.Background. Endothelium-derived relaxing factor, recently identified as nitric oxide, is a potent relaxant of coronary smooth muscle.Methods. The left anrterior descending coronary artery was perfused through an extracorporeal bypass tube placed in the carotid artery in 56 open chest dogs. After hemodynamic stabilization, we occluded this bypass tube to decrease coronary blood flow to one third of the control flow. Thereafter, we maintained a constant coronary perfusion pressure(40.9 ± 3.1mm Hg).Results. Under ischemic conditions, the coronary arteriovenous differences in nitrate and nitrite (end products of nitric oxide) increased (from 3.5 ± 0.4 [mean ± SEM] to 12.9 ± 2.1 μmol/liter, p < 0.01).
0-Monomethyl
-arginine (3 μg/kg body weight per min, intracoronary) decreased the coronary arteriovenous differences in nitrate and nitrite (5.0 ± 0.9 μmol/liter, p < 0.05) and coronary blood flow (from 29.8 ± 0.5 to 18.1 ± 1.1 ml/100 g per min, p < 0.001). Fractional shortening (from 3.7 ± 1.0 to −1.3 ± 0.7%, p < 0.001) and lactate extraction ration (from −44.0 ± 4.1 to −59.2 ± 4.9%, p < 0.005) of the perfused area also decreased. These values were restored by the concomitant administration of
-arginine. Blood flow to the endomyocardium was decreased relative to the epimyocardium. A reduction in coronary blood flow and worsening of myocardial contractile and metabolic functions due to the administration of
G-monomethyl
-arginine during ischemia were observed in denervated hearts. A reduction in coronary blood flow in ischemic myocardium was observed with the administration of
W-nitro-
-arginene methyl ester as well, although neither
W-nitro-
-arginine methyl ester nor
G-monomethyl
-arginine changed coronary blood flow and myocardial contractile and metabolic functions in the nonischemic myocardium. The cyclic guanosine monophosphate content of epicardial coronary artery increased due to myocardial ischemia; this increased was attenuated with
G-monomethyl
-arginine treatment.Conclusions. We conclude that endogenous nitric oxide predominantly decreases the coronary vascular resistance of ischemic endomyocardium, thereby improving myocardial contractility and metabolic function. 相似文献
99.
Masumeh Bagherzadeh Cham Mohammad Ali Mohseni-Bandpei Mahmood Bahramizadeh Saeed Kalbasi Akbar Biglarian 《Neurological sciences》2018,39(6):1079-1084
Peripheral sensory neuropathy seems to be the main risk factor for diabetic foot ulceration. Previous studies demonstrated that stochastic resonance can improve the vibrotactile sensation of diabetic patients. The aim of this study was to evaluate the effects of Vibro-medical insole on pressure and vibration sensation in diabetic patients with mild-to-moderate peripheral neuropathy. A total of 20 patients with mild-to-moderate diabetic neuropathy were included in the pre-test and post-test clinical trial study. Vibro-medical insole consists of medical insole and vibratory system. Medical insole was made independently for each participant and vibratory system was inserted in it. Pressure and vibration sensation were evaluated before and after 30-min walking with Vibro-medical insole. Semmes-Weinstein monofilaments and tuning fork were used to evaluate pressure and vibration sensation, respectively. Pressure sensation showed significantly improvement using Vibro-medical insole at the heel, first and fifth metatarsophalangeal heads, and hallux of both feet in all participants (p?<?0.001). Vibration sensation also improved at the big toe of both feet with 256 Hz tuning fork (p?<?0.05) but no statistically significant effect was found with 128 Hz tuning fork (p?>?0.05). Vibro-medical insole significantly improved pressure and vibration sensation of the foot in diabetic patients with mild-to-moderate peripheral neuropathy. The results suggest that Vibro-medical insole can be used for daily living activities to overcome sensory loss in diabetic neuropathy patients. 相似文献
100.
Impact of Insurance Provider on Overall Costs in Failed Back Surgery Syndrome: A Cost Study of 122,827 Patients
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