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排序方式: 共有429条查询结果,搜索用时 31 毫秒
1.
Fifteen parameters that play a role in the optimal transmission of therapeutic signals by inductively coupled implantable neurostimulator have been investigated. For this purpose, at first, a model of the system was constructed from which the system transfer function was obtained. Then, the relationship between the transfer gain and each parameter was evaluated using mathematical equations and a specifically built computer program. This study showed that the gain could be increased selecting small values for some parameters (the number of active coil windings, first radii of inner and outer paths of the core, heights of the core base and windings, position under the skin, internal resistances of the active and passive coils, tissue impedance between the contacts of electrode), and high values for the others (the number of passive coil windings, second radii of inner and outer paths of the core, frequency of the signal, relative magnetic permeability of the core). Critical saturation values were another considerable point. The nearest commercially available standard values should be preferred in practical applications. 相似文献
2.
Mehmet Erturk Hamdi Pusuroglu Ali Kemal Kalkan Muhammet Gurdogan Ibrahim Faruk Akturk 《Clinical and experimental hypertension (New York, N.Y. : 1993)》2014,36(8):572-578
Objectives: To evaluate subclinical left ventricular and right ventricular systolic impairment in dipper and non-dipper hypertensives by using isovolumic acceleration.Methods: About 45 normotensive healthy volunteers (20 men, mean age 43?±?9 years), 45 dipper (27 men, mean age 45?±?9 years) and 45 non-dipper (25 men, 47?±?7 years) hypertensives were enrolled. Isovolumic acceleration was measured by dividing the peak myocardial isovolumic contraction velocity by isovolumic acceleration time.Results: Non-dippers indicated lower left ventricular (2.2?±?0.4?m/s2 versus 2.8?±?1.0?m/s2, p?0.01) and right ventricular isovolumic acceleration values (2.8?±?0.8?m/s2 versus 3.5?±?1.0?m/s2, p?=?0.012) compared with dippers. Left ventricular mass index (p?=?0.001), interventricular septal thickness (p?=?0.002) and myocardial performance index (p?0.001) were negatively correlated with left ventricular isovolumic acceleration. Left ventricular septal thickness (p?=?0.002), mass index (p?=?0.001) and right ventricular myocardial performance index (p?0.001) were negatively correlated with right ventricular isovolumic acceleration.Conclusion: The present study demonstrates that non-dipper hypertensives have increased left and right ventricular subclinical systolic dysfunction compared with dippers. Isovolumic acceleration is the only echocardiographic parameter in predicting this subtle impairment. 相似文献
3.
4.
Ali Akal Turgay Ulas Tugba Goncu Muhammet Emin Guldur Sezen Kocarslan Abdullah Taskin 《Cutaneous and ocular toxicology》2015,34(2):139-143
Objective: In this experimental study, we investigated the possible effects of intracameral moxifloxacin on oxidative stress parameters and endothelial cell morphology in corneal tissue.Methods: In total, 30 rats were randomly assigned to three groups of 10 rats: the sham group (Group 1, n?=?10); the control group (Group 2), where balanced salt solution (BSS) was administered at a dose of 0.01?cc (n?=?10); and the treatment group (Group 3), where moxifloxacin was administered at a dose of 0.05?mg/0.01?cc (n?=?10). Total antioxidant status (TAS) and total oxidant status (TOS) in corneal tissue and blood samples were measured and the oxidative stress index (OSI) was calculated. Also, corneal tissue histopathology was evaluated with caspase-3 and caspase-8 staining. Apoptotic activity was also evaluated.Results: In blood samples, TAS, TOS, and OSI levels were not statistically significantly different (all p?>?0.05). Compared with the sham and control groups, TOS and OSI levels in cornea tissue were significantly different in the moxifloxacin group (all p?0.05). However, compared with the control group, no statistically significant difference was found in the sham group (all p?>?0.05). Compared with the sham and control groups, apoptotic activity was higher in the moxifloxacin group, in both immunohistochemical staining for caspase-3 and caspase-8.Conclusions: Intracameral moxifloxacin injection seems to be safe systemically, but it may have toxic effects on corneal tissues, as suggested by oxidative stress parameters and a histopathological evaluation. 相似文献
5.
Rabia Akan Karolis Parfeniukas Carmen Vogt Muhammet S. Toprak Ulrich Vogt 《RSC advances》2018,8(23):12628
Metal-assisted chemical etching (MACE) reaction parameters were investigated for the fabrication of specially designed silicon-based X-ray zone plate nanostructures using a gold catalyst pattern and etching solutions composed of HF and H2O2. Etching depth, zone verticality and zone roughness were studied as a function of etching solution composition, temperature and processing time. Homogeneous, vertical etching with increasing depth is observed at increasing H2O2 concentrations and elevated processing temperatures, implying a balance in the hole injection and silica dissolution kinetics at the gold–silicon interface. The etching depth decreases and zone roughness increases at the highest investigated H2O2 concentration and temperature. Possible reasons for these observations are discussed based on reaction chemistry and zone plate design. Optimum MACE conditions are found at HF : H2O2 concentrations of 4.7 M : 0.68 M and room temperature with an etching rate of ≈0.7 μm min−1, which is about an order of magnitude higher than previous reports. Moreover, our results show that a grid catalyst design is important for successful fabrication of vertical high aspect ratio silicon nanostructures.Specially designed X-ray zone plates with high aspect-ratios have been fabricated via metal-assisted chemical etching, by controlling the reaction kinetics. 相似文献
6.
Gokhan Soker Bozkurt Gulek Eda Soker Omer Kaya Ibrahim Inan Muhammet Arslan Kaan Esen Derya Memis Cengiz Yilmaz 《Journal of Medical Ultrasonics》2018,45(2):287-294
Purpose
In this study, we aimed to establish a quantitative threshold value in the diagnosis of subacromial impingement syndrome by measuring the thickness of the subacromial bursa during abduction and adduction.Materials and methods
Forty-five patients with subacromial impingement syndrome and 54 healthy individuals underwent dynamic shoulder ultrasonography. The subacromial bursa, between the supraspinatus tendon margin and peribursal adipose tissue, was measured between the acromion and humeral head at its widest part. The subacromial impingement ratio was calculated by dividing the subacromial bursa thickness during abduction to the subacromial bursa thickness during adduction. Shapiro–Wilk test was used in the assessment of normal distribution of parameters.Results
The mean subacromial bursa thickness in the abduction position was 1.8 ± 1.1 mm in the study group and 0.9 ± 0.3 mm in the control group. The mean subacromial bursa thickness in the adduction position was 0.9 ± 0.5 mm in the study group and 0.8 ± 0.3 mm in the control group. The subacromial impingement ratio showed a statistically significant difference between groups (p < 0.0001), and the ratio being 2.0 ± 0.5 in the study group and 1.2 ± 0.1 in the control group. For measurements performed in the abduction position, the best cut-off value was calculated as 1.3 mm, and sensitivity and specificity were 70.6 and 85.2%, respectively. The best cut-off value was 1.4 for the subacromial impingement ratio, and sensitivity and specificity were 88.2 and 96.3%, respectively.Conclusion
Subacromial impingement ratio is a very practical and reliable method in subacromial impingement syndrome diagnosis.7.
Mahmut Akyol Muhammet Kazm Erol Ozdemir Ozdemir Deniz Turgut Coban Ahmet Burak Bilgin Esin Sogutlu Sari Elif Betul Turkoglu 《国际眼科》2015,8(1):23-28
AIM
To investigate the association of serum glucocorticoid kinase gene-1 (SGK-1) DNA variants with chronic central serous chorioretinopathy (CSC).METHODS
We enrolled 32 eyes of 32 patients who were diagnosed with chronic CSC and composed 32 normal eyes as a control group. Peripheral blood was used for DNA extraction and polymerase chain reaction (PCR) amplification. SGK1 gene was sequenced by using BigDye® Terminator v3.1 cycle sequencing KIT (Applied Biosystems, Foster City, CA, USA). The SGK1 gene and its variants were investigated in CSC patient group and control group.RESULTS
We identified a new polymorphism M32V in two person in the patient group (Minor allele frequency (MAF)=0.009) on the region of 1-60 amino acids. The rs1057293 was located in the encoder region of the SGK 1 gene but not associated with CSC (P=0.68). An intrinsic rs1743966 is also not associated (P=0.28).CONCLUSIONS
The new polymorphism M32V is located on the region of 1-60 amino acids which is necessary for localization to the mitochondria in CSC patient. This mutation is probably important for the energy metabolism and plays an important role in the cellular response to hyperosmotic stress and other stress stimuli. Both rs1057293 and rs1743966 are not associated with CSC. 相似文献8.
Guven Yenmis Elif Yaprak Sarac Nail Besli Tugba Soydas Cihan Tastan Derya Dilek Kancagi Muhammet Yilanci Kazim Senol Onur Olgac Karagulle Cumhur Gokhan Ekmekci Ercument Ovali Matem Tuncdemir Turgut Ulutin Gonul Kanigur Sultuybek 《Acta histochemica》2021,123(4):151709
Current evidence strongly suggests that aberrant activation of the nuclear factor kappa B (NF-kB) signaling cascade is connected to carcinogenesis. The matrix metalloproteinases (MMP) which are also the key agents for tumor metastasis may be potent candidates for tumor diagnosis in clinics. In this in vitro study, we hypothesized that metformin with an effective dose can inhibit tumor cell proliferation and metastasis by modulating the expressions of MMP-2 and -9 and interfering with NF-kB signaling in primary breast cancer cells (PBCCs). 300 000 cells per ml were obtained from biopsies of breast tumors from five human donors. The cell viability and proliferation were tested. Immunocytochemistry was performed for MMP-2, MMP-9, and NF-kB, and enzyme-linked immunosorbent assay for NF-kB activity, quantitative real-time PCR for RELA/p65, IkBα, MMP-2, and MMP-9. Three different doses of metformin (5, 10, and 25 mM) (Met) reduced the viability and proliferation of PBCCs in a dose-dependent manner, maximum inhibition was observed at 25 mM Met. The expression of RELA/p65 was not affected by 25 mM Met. Nuclear immunoreactivity and activity of NF-kB reduced while cytoplasmic NF-kB (p65) elevated by 25 mM Met compared to non-treatment (P < 0.05). The expression and immunoreactivity of MMP-9 but not MMP-2 were decreased by 25 mM Met treatment, compared with the non-treatment (P < 0.05). Metformin may have an essential antitumor role in the invasion and metastasis pathways of PBCCs by downregulating the MMP-9 expression blocking both the activity and nuclear translocation of NF-kB. 相似文献
9.
Mujgan Gungor Hatipoglu Sermet Inal Sahin Kabay Muhammet Kasim Cayci Ay?enur Deger Halil Isa Kuru Sayit Altikat Gizem Akkas 《Acta stomatologica Croatica》2015,49(4):325-330
The aim
The aim of this study was to investigate the effect of dexketoprofen trometamol, meloxicam, diclofenac sodium on any untreated alveolar bone when they are used as drugs for another indication.Materials and Methods
Twenty eight male Spraque-Dawley rats were randomized into four groups as dexketoprofen trometamol (Group I), meloxicam (Group II), diclofenac sodium (Group III) and control group. Nonsteroidal anti-inflammatory drugs (NSAID) were administered after a fibula fracture for 10 days. Untreated alveolar bone was histopathologically examined for spongious bone density, osteoclastic density and osteoblastic density.Results
Spongious bone density was lower in study groups (Group I, group II and group III) than the control group (p<0.05). In contrast, the increase in osteoclastic density was observed in other groups apart from the control group (p<0.05). Osteoblastic density was evaluated and it was determined that group II and group III had lower results than the control group (p<0.05) but group I was equal to the control group.Conclusion
This study showed that systemically administrated NSAIDs have the potential to affect untreated alveolar bone. This should also be considered in long term use of NSAIDs.Key Words: Non-steroidal anti-inflammatory agents, bone remodeling, osteoblast, osteoclast, maxillary bone 相似文献10.