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The synthesis of large-size graphene materials is still a central focus of research into additional potential applications in various areas. In this study, large-size graphene platelets were successfully produced by pulsed discharge of loose graphite strips with a dimension of 2 mm × 0.5 mm × 80 mm in distilled water. The graphite strips were made by pressing and cutting well-oriented expanded graphite paper. The recovered samples were characterized by various techniques, including TEM, SEM, optical microscopy (OM), atomic force microscopy (AFM), XRD and Raman spectroscopy. Highly crystalline graphene platelets with a lateral dimension of 100-200 µm were identified. The high yield of recovered graphene platelets is in a range of 90-95%. The results also indicate that increasing charging voltage improves the yield of graphene platelets and decreases the number of graphitic layers in produced graphene platelets. The formation mechanism of graphene platelets was discussed. This study provides a one-step cost-effective route to prepare highly crystalline graphene platelets with a sub-millimeter lateral size.
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Background: The objective of this pilot study was to evaluate the cerebral effects of laser stimulation and traditional needle acupuncture in patients after stroke. Methods: Seventeen stroke patients (12 female and five male; mean age ± SD: 66.5 ± 12.9 years) were randomly selected in a stroke rehabilitation hospital. Patients' regional cerebral blood oxygen saturation (rSO2) values were recorded before, during, and after needle acupuncture (scalp, ear and body) as well as before, during, and after corresponding laser stimulation (red laser, four points: 100 mW, 658 nm, 500 µm; yellow laser, one point: 50 mW, 589 nm, 500 µm; infrared laser, three points: 100 mW, 810 nm, 500 µm; green laser, one point: 5 mW, 532 nm, 500 µm) in a cross-over study design. Results: There were no significant changes after needle acupuncture in the phases immediately after needle insertion or during acupuncture stimulation. However, after manual needle acupuncture and after laser stimulation, the majority of the rSO2 values showed increases. The highest value (+3%) was reached after laser stimulation treatment. Heart rate and blood pressure before and after the treatments did not show significant alterations. Conclusions: Changes in local cerebral oxygen saturation could be quantified, although confirmation may only be expected after extensive follow-up studies.
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To study the microstructural evolution in high-strain-rate shear deformation of Ti-5Al-5Mo-5V-1Cr-1Fe (Ti-55511) alloy, a series of forced shear tests of hat-shaped specimens have been conducted using a split Hopkinson pressure bar combined with the "strain-frozen" technique. A localized shear band is induced in Ti-55511 alloy in these tests. The experimental results demonstrate that the flow stress in hat-shaped specimens remains constant (about 600 MPa) and is independent of punching depth. The width of the adiabatic shear band increases with increasing punching depth and tends to saturate at 30 µm, and the estimation of the adiabatic shear band (ASB) width in hat-shaped (HS) specimens has been modified. Relying on the experimental results, thermal softening has a minor effect on the onset of the adiabatic shear band and dynamic recrystallization formation, and the nucleation mechanism for dynamic recrystallization is strain-induced boundary migration and subgrain rotation and coalescence. In addition, we suggest the concept of adhesive fracture as the dynamic failure mechanism for Ti-55511 alloy.
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The objective of this study was to investigate the impact of femoral head perfusion by traditional Chinese medicine Guanxinning injection promoting blood circulation for removing blood stasis on the expression of Bcl-2 and Bax induced by liquid nitrogen freezing-mediated femoral head necrosis. 90 rabbits were randomized into three groups. Normal control group was not subjected to any medication. Saline and Guanxinning group were perfused with 0.9% saline and Guanxinning injection once every three days through the hip joint, respectively. Six animals in each group were sacrificed at weeks 1, 3, 6, 9, and 12. PCR and Western blot measured the expressions of Bcl-2 and Bax in the femoral head. The bax expression in the Guanxinning group reduced at the third week significantly compared to the normal control group (P < 0.01). The Bcl-2 expression in the Guanxinning group increased substantially at the third week (P < 0.05 or P < 0.01). Prolonged treatment elevated the expression of Bcl-2 in the Guanxinning group while that of Bax reduced remarkably (P < 0.01). Moreover, the ratio of Bcl-2 to Bax increased gradually in the Guanxinning group with prolonged drug administration. Guanxinning injection can inhibit the cell apoptosis of femoral head necrosis through the treatment by femoral head perfusion.
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BACKGROUND: The role of the piriform cortex (PC) in olfactory information processing remains largely unknown. The anterior part of the piriform cortex (APC) has been the focus of cortical-level studies of olfactory coding, and associative processes have attracted considerable attention as an important part in odor discrimination and olfactory information processing. Associational connections of pyramidal cells in the guinea pig APC were studied by direct visualization of axons stained and quantitatively analyzed by intracellular biocytin injection in vivo. RESULTS: The observations illustrated that axon collaterals of the individual cells were widely and spatially distributed within the PC, and sometimes also showed a long associational projection to the olfactory bulb (OB). The data showed that long associational axons were both rostrally and caudally directed throughout the PC, and the intrinsic associational fibers of pyramidal cells in the APC are omnidirectional connections in the PC. Within the PC, associational axons typically followed rather linear trajectories and irregular bouton distributions. Quantitative data of the axon collaterals of two pyramidal cells in the APC showed that the average length of axonal collaterals was 101 mm, out of which 79 mm (78% of total length) were distributed in the PC. The average number of boutons was 8926 and 7101, respectively, with 79% of the total number of boutons being distributed in the PC. The percentage of the total area of the APC and the posterior piriform cortex occupied by the average distribution region of the axon collaterals of two superficial pyramidal (SP) cells was about 18 and 5%, respectively. CONCLUSION: Our results demonstrate that omnidirectional connection of pyramidal cells in the APC provides a substrate for recurrent processes. These findings indicate that the axon collaterals of SP cells in the PC could make synaptic contacts with all granule cells in the OB. This study provides the morphological evidence for understanding the mechanisms of information processing and associative memory in the APC.
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Axones , Corteza Piriforme/citología , Células Piramidales/citología , Animales , Tamaño de la Célula , Femenino , Cobayas , Lisina/análogos & derivados , Masculino , Bulbo Olfatorio/citología , Vías Olfatorias/citología , FotomicrografíaRESUMEN
Hypertension is one of the major risk factors for cardiovascular disease worldwide. Over 70% of the patients use antihypertensive drugs, so nonpharmacological treatments in addition to the medication are important. Our goal was to investigate acupuncture treatment on the Quchi acupoint using heart rate (HR) and heart rate variability (HRV) and to find out whether there is a laterality in acute effects. Sixty hypertensive patients (36 female, 24 male; mean age ± SD 55.8 ± 9.7 years) were randomly assigned to two manual needle acupuncture groups (group A: left Quchi (LI11) acupoint, group B: right Quchi acupoint). There was a significant (P < 0.05) decrease in HR immediately after inserting and stimulating the needle at the left and the right Quchi acupuncture point. In contrast, total HRV increased immediately after inserting the needle, but this increase was significant only towards the end of the stimulation phase and after removing the needle. There were some differences between stimulation of the left and right Quchi acupoint, but they remained insignificant. This study provides evidence that there is a beneficial effect on heart rate variability in patients with hypertension and that there are some effects of laterality of the acupoint Quchi.
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We observed the effect of scalp point cluster-needling treatment on learning and memory function and neurotransmitter levels in rats with vascular dementia (VD). Permanent ligation of the bilateral carotid arteries was used to create the VD rat model. A Morris water maze was used to measure the rats' learning and memory function, and the changes in neurotransmitter levels in the rats' hippocampus were analyzed. The results show that scalp point cluster-needling can increase the VD rat model's learning and memory score. The VD rat model's learning and memory score was significantly different when compared with that of the sham operation group (P < 0.05). Hippocampal acetylcholine (ACh), dopamine (DA), and 5-hydroxytryptamine (5-HT) concentrations significantly decreased in the rat model. Compared with the model group, the scalp point cluster-needling group's ACh concentration markedly increased and DA and 5-HT levels increased as well. In conclusion, scalp point cluster-needling can improve learning and memory function in VD rats, and its function may be related to an increase in neurotransmitter release.
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Tongue acupuncture (TA) is a method which is not used in western medicine and even in China it is applied very rarely in clinical practice. This study aimed at investigating whether additional TA can improve the efficacy of body acupuncture (BA) in patients with depression. Twenty patients with a mean age of ± SD of 42.9 ± 11.2 years were randomly divided into two groups (n = 10 patients each), one group receiving BA (Zusanli, Sanyinjiao, Neiguan, Shenting, Yintang, and Baihui) and the other receiving BA and TA (Liver, Heart, and Brain). The quantitative and qualitative outcome measures were heart rate (HR), heart rate variability (HRV), and different clinical scores. We found that in both groups all scores and HR improved significantly, whereas HRV increased partly significantly. It seems that TA can enhance acute and treatment effects of BA in patients with depression. The investigation of de qi sensation in TA needs further attention.
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The goal of this study was to investigate the impact and acceptability of providing continuous auricular electroacupuncture as an adjunct to conventional medications for patients with depression. Ten patients with a mean age ± SD of 43.3 ± 10.4 years were able to provide informed consent. The quantitative and qualitative outcome measures were heart rate, heart rate variability (HRV), and different clinical scores. The study documented that a special kind of auricular electro acupuncture, applied over a period of three days, can improve various aspects of quality of life significantly but also highlighted the significant increase of HRV whilst having acupuncture treatment. In conclusion, our study shows stimulation-related and quantifiable clinical and physiological alterations in parameters after continuous auricular acupoint stimulation in patients with depression. Improved access to electro acupuncture treatment would be of major benefit for these patients. Further studies are necessary in order to verify the gained results.
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It has been shown in previous studies that the autonomic nervous system can be affected by acupuncture. Within this study, teleacupuncture between China and Austria is used for quantifying the effects of heart rate (HR) and heart rate variability (HRV) in 33 Chinese patients (27 females, 6 males; mean age ± SD 49.5 ± 13.1 years; range 22-72 years) suffering from depression. Electrocardiographic signals before, during, and after acupuncture at the acupoint Baihui (GV20) were recorded in Harbin and analyzed in Graz using teleacupuncture. HRV data were analyzed in the time and frequency domain. Mean HR decreased significantly (P < 0.05) during and after acupuncture, whereas total HRV increased significantly after the third acupuncture stimulation period (P < 0.05) and also 5-10 minutes after (P < 0.05) acupuncture. The study shows that HRV could be a useful parameter for quantifying clinical effects of acupuncture on the autonomic nervous system.