Inductively coupled transmission of neuro-active signals: analysis of optimal parameters

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.     

Comparison of subclinical left and right ventricular systolic dysfunction in non-dipper and dipper hypertensives: impact of isovolumic acceleration

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?2 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?p?=?0.002), mass index (p?=?0.001) and right ventricular myocardial performance index (p?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.     

Life experiences of women with breast cancer in south western Turkey: A qualitative study

PurposeThis qualitative study explores the experience of women living with breast cancer.MethodsThe study was conducted among eight women with ongoing breast cancer chemotherapy treatment, which occurred in an ambulatory unit. The data were collected using semi-structured and in-depth individual interviews. All interviews were tape-recorded, and the results were obtained by analysing the content of the recorded data.ResultsThree major themes related to the experiences of women living with breast cancer were identified. They are as follows: (1) needs (the need for spouse and family support, the need to worship, and the need to receive and share information), (2) living with losses (loss of the breast and of one’s hair), and (3) changes (changes in one’s normal life, change in self-perception, changes in the perception of the value of health, and a greater appreciation for life).ConclusionsThis study was conducted to increase awareness concerning women’s perceptions of their care and various needs during breast cancer treatment. The results of this study challenge health care providers and educators to be more aware of the difficulties that women face when living with breast cancer.     

Serum copper and zinc concentrations in patients with chronic hepatitis C

The aim of this study was to measure the alterations in serum trace elements, including zinc and copper in patients with chronic hepatitis C and to compare them with the results of healthy individuals. Seventeen patients with chronic hepatitis C and 17 healthy individuals were included in this study. Serum zinc and cooper concentrations were measured by using atomic absorption spectrophotometer of patients with chronic hepatitis C and the results were statistically compared with those of healthy individuals. Serum zinc concentrations were 105.6+/-22.8 microg/dl in patients with chronic hepatitis C and 94.41+/-19 microg/dl in healthy controls, respectively. Serum copper concentrations were 103.17+/-20.8 microg/dl in patients with chronic hepatitis C and 90.8+/-14.3 microg/dl in healthy subjects, respectively. Serum zinc and copper concentrations were not found statistically different in patients with chronic hepatitis C compared with those of healthy individuals (p>0.05). In conclusion, serum trace element concentrations did not show statistical alterations in patients with chronic hepatitis C compared to healthy subjects.     

Does moxifloxacin alter oxidant status in the cornea? An experimental study

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?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.     

Reaction control of metal-assisted chemical etching for silicon-based zone plate nanostructures

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.     

Sonographic assessment of subacromial bursa distension during arm abduction: establishing a threshold value in the diagnosis of subacromial impingement syndrome

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.

     

A novel mutation of sgk-1 gene in central serous chorioretinopathy

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.