Amorphous FeCoCrSiB Ribbons with Tailored Anisotropy for the Development of Magnetic Elements for High Frequency Applications

The ferromagnetic resonance (FMR) in the frequency range of 0.5 to 12.5 GHz has been investigated as a function of external magnetic field for rapidly quenched Fe₃Co₆₇Cr₃Si₁₅B₁₂ amorphous ribbons with different features of the effective magnetic anisotropy. Three states of the ribbons were considered: as-quenched without any treatment; after relaxation annealing without stress at the temperature of 350 °C during 1 h; and after annealing under specific stress of 230 MPa at the temperature of 350 °C during 1 h. For FMR measurements, we adapted a technique previously proposed and tested for the case of microwires. Here, amorphous ribbons were studied using the sample holder based on a commercial SMA connector. On the basis of the measurements of the reflection coefficient S_11, the total impedance including its real and imaginary components was determined to be in the frequency range of 0.5 to 12.5 GHz. In order to confirm the validity of the proposed technique, FMR was also measured by the certified cavity perturbation technique using a commercial Bruker spectrometer operating at X-band frequency of 9.39 GHz. As part of the characterization of the ribbons used for microwave measurements, comparative analysis was performed of X-ray diffraction, optical microscopy, transmission electron microscopy, inductive magnetic hysteresis loops, vibrating sample magnetometry, magneto-optical Kerr effect (including magnetic domains) and magnetoimpedance data for of all samples.     

The role of interferon-gamma release assay in tuberculosis control

Tuberculosis is still one of the major global public health threats. Countries with low incidence must focus on exhausting the reservoir of future cases by preventing reactivation. Therefore, it is important to identify and effectively treat those individuals who have latent tuberculosis infection and who may develop active disease. The tuberculin skin test has been the standard for detection of immune response against M. tuberculosis since the beginning of the 20th century. The new millennium has brought advancement in the diagnosis of latent tuberculosis infection. The name of the new blood test is interferon-gamma release assay (IGRA). Croatia is a middle-incidence country with a long decreasing trend and developed tuberculosis control. To reach low incidence and finally eliminate tuberculosis, its tuberculosis programme needs a more aggressive approach that would include intensive contact investigation and treatment of persons with latent tuberculosis infection. This article discusses the current uses of IGRA and its role in tuberculosis control.     

Theoretical investigation of photon partial pathlengths in multilayered turbid media

Functional near infrared spectroscopy (fNIRS) is a valuable tool for assessing oxy- and deoxyhemoglobin concentration changes (Δ[HbO] and Δ[HbR], respectively) in the human brain. To this end, photon pathlengths in tissue are needed to convert from light attenuation to Δ[HbO] and Δ[HbR]. Current techniques describe the human head as a homogeneous medium, in which case these pathlengths are easily computed. However, the head is more appropriately described as a layered medium; hence, the partial pathlengths in each layer are required. The current way to do this is by means of Monte Carlo (MC) simulations, which are time-consuming and computationally expensive. In this work, we introduce an approach to theoretically calculate these partial pathlengths, which are computed several times faster than MC simulations. Comparison of our approach with MC simulations show very good agreement. Results also suggest that these analytical expressions give much more specific information about light absorption in each layer than in the homogeneous case.     

Improvement of a method for the sequential determination of Pb, Ra, and uranium isotopes by LSC and alpha-particle spectrometry

In a previous paper the authors proposed a sequential method for the determination of isotopes of uranium, thorium, radium, and lead from environmental samples using alpha-particle spectrometry and LSC techniques. Although the radiochemical yields were suitable when the assays were performed on synthetic samples, application to real environmental samples caused a major decrease in the radiochemical yield, especially for uranium in inorganic samples (soils). A modification of the procedure is described that overcomes this drawback.     

Advances in urinary proteome analysis and biomarker discovery

Noninvasive diagnosis of kidney diseases and assessment of the prognosis are still challenges in clinical nephrology. Definition of biomarkers on the basis of proteome analysis, especially of the urine, has advanced recently and may provide new tools to solve those challenges. This article highlights the most promising technological approaches toward deciphering the human proteome and applications of the knowledge in clinical nephrology, with emphasis on the urinary proteome. The data in the current literature indicate that although a thorough investigation of the entire urinary proteome is still a distant goal, clinical applications are already available. Progress in the analysis of human proteome in health and disease will depend more on the standardization of data and availability of suitable bioinformatics and software solutions than on new technological advances. It is predicted that proteomics will play an important role in clinical nephrology in the very near future and that this progress will require interactive dialogue and collaboration between clinicians and analytical specialists.     

Ovariectomy Enhances Acetylcholinesterase Activity But Does Not Alter Ganglioside Content in Cerebral Cortex of Female Adult Rats

In the present work we investigated the effect of ovariectomy on acetylcholinesterase (AChE) activity and ganglioside content in cerebral cortex of female rats. We also studied the activity of butyrylcholinesterase (BuChE) in serum of these animals. Adult Wistar rats were divided into three groups: (1) naive females (control), (2) sham-operated females and (3) castrated females (ovariectomy). Thirty days after ovariectomy, rats were sacrificed by decapitation without anaesthesia. Blood was collected and the serum used for BuChE determination. Cerebral cortex was homogenized to determine AChE activity and extracted with chlorophorm:methanol for ganglioside evaluation. Results showed that rats subjected to ovariectomy presented a significant increase of AChE activity, but did not change the content and the profile of gangliosides in cerebral cortex when compared to sham or naive rats. BuChE activity was decreased in serum of rats ovariectomized. Our findings suggest that the alteration in the activity of brain AChE, as well as serum BuChE activity caused by ovariectomy may contribute to the impaired cognition and/or other neurological dysfunction found in post-menopausal women.     

Effect of different swallow time intervals on the nutcracker esophagus

OBJECTIVE: Nutcracker esophagus (NE) is defined as the presence of peristaltic contractions in which the average distal esophageal amplitude is greater than 180 mm Hg. The underlying mechanism responsible for these abnormalities is not known. The aim of this study was to test the hypothesis that NE might be caused by a defect in the inhibitory pathway controlling esophageal peristalsis. METHODS: Eight patients with NE (seven women, 1 man, mean age 50 yr) and eight age- and sex-matched normal volunteers (seven women, 1 man, mean age 48 yr) underwent a special protocol using three-channel (3, 8, and 16 cm above the lower esophageal sphincter) solid state esophageal manometry to evaluate deglutitive inhibition. Ten pairs of 5 ml of wet swallows were given at each of five different time intervals (30, 20, 15, 10, and 5 s). Pairs of swallows were spaced by 30 s, and different time intervals were spaced by 1 min. Tracings were recorded using a computer program and blindly automatically analyzed for both amplitude and duration of the contraction separately for the first and second swallow of each pair. Presence of deglutitive inhibition or muscle refractoriness was assessed according to interactions between the first and second swallow of the pair. Results were found abnormal when larger than the mean percent variation of the second and first swallow calculated for the 30-s interval, considered as baseline for each participant. Statistics included paired and nonpaired nonparametrical comparisons as appropriate. RESULTS: The median amplitude for the NE was 202 mm Hg (range 186-376) and for the controls was 118 mm Hg (range 64-167) (p = 0.0002). The median duration in the NE group was 5.1 s (range 4-9.3) versus 4.1 (range 3.3-5.0) for the controls (p = 0.02). The percent variation in duration (p = 0.31), amplitude (p = 0.42), and propagation velocity of the peristaltic waves (p = 0.69) did not differ between the control and NE groups. Peristalsis frequency dropped at the 5-s interval for both studied groups (p = 0.84). CONCLUSION: Central and local inhibitory mechanisms induced by closely timed swallows are preserved in the NE and do not explain the mechanism of the high amplitude and long duration contractions.     

Secondary amyloidosis (AA) and renal disease

Amyloidosis is a disease resulting from extracellular deposition of fibrillar protein in various organs. AA amyloidosis may complicate chronic inflammatory diseases, chronic infections and another chronic diseases. We review 31 patients (13 males and 18 females) with biopsy proven renal or rectal AA amyloidosis, referred to out hospital between january 1999 and november 2002. Renal failure was defined as serum creatinine > or = 1.5 mg/dl. Mean age was 58.4 +/- 15.7 years. The causes of AA amyloidosis were an underlying chronic rheumatologic disease (51.6%), chronic infection (41.9%) and a chronic inflammatory intestinal disorder (6.5%). Renal failure (RF) was detected in 20 patients (61.2%) and proteinuria and hematuria were found in 90.3% and 45.5 respectively. Proteinuria at diagnosis was 5.2 +/- 3.9 g/24 h and mean serum creatinine 3.5 +/- 3.7 mg/dl. Survival of patients without dialysis was 66.8 (51.1% RF, 90.9% non-RF) and 53.4% (38.2 RF, 77.9% non-RF) at 12 and 24 months respectively (p = 0.017). End-stage renal disease developed in 13 patients (41.9%). Ten patients were maintained on hemodialysis and 3 on CAD. Survival in dialysis at 6 and 12 months was 68.3% and 42.7% respectively. Fifteen patients died and the main causes of death were: infections (46.6) haemorrhagic complications (33.3%), cardiovascular events (13.3%) and cachexia (6.6%).