Programmable constant phase element realization with crossbar arrays.

INTRODUCTION: Constant Phase Elements (CPEs) have been widely used in many applications due to the extra degree of freedom, which offers new responses and behaviors. OBJECTIVES: This paper proposes a new programmable CPE realization using resistive crossbar arrays. By programming the resistive devices, different CPEs can be obtained. METHODS: The proposed realization can be approximated as a weighted sum of low and high pass filters having the same cut-off frequency (i.e., Lapicque model). The closed-form approximation expression is derived, and then the Flower Pollination Algorithm (FPA) is used to find the optimal values of the network components. RESULTS: Different design examples are given over the frequency range of 106-109 rad/sec to prove the ability of this realization achieving any fractional order with less than 5% relative error in both phase and pseudo-capacitance. Monte-Carlo simulations are performed to evaluate the sensitivity of the proposed realization against device variability. In addition, multiple CPEs can be designed at the same time by utilizing the multiple ports of the crossbar array. The proposed realization is compared with two other state-of-art realizations showing comparable results as standalone realization and within fractional-order relaxation oscillator application. CONCLUSION: The proposed crossbar realization has proven its ability to realize any CPE with acceptable error. In addition, this multiple-port design offers high flexibility and on-the-fly switching of the CPE.

Transport kinetics of chromium in perfused human placental lobule in late gestation: in vitro study.

Objective: Reports relating to maternal-fetal transport kinetics of chromium, an essential trace element in the human pregnancies are scanty. Hence, we thought it interesting to investigate the transport kinetics of this trace element in the human placenta in late gestation in vitro. Methods: Human placentae were collected immediately after delivery from normal uncomplicated pregnancies. Chromium chloride solution (GFS Chem Inc, Ohio, USA) at 10 times the physiological concentrations and antipyrine (Sigma Chem Co., St. Louis, USA) as internal reference marker was injected as a single bolus (100 µl) into the maternal arterial circulation of perfused placental lobules and perfusate samples were collected from maternal and fetal circulations over a study period of 5 minutes. National culture and Tissue collection medium, diluted with Earle's buffered salt solution was used as the perfusate. Serial perfusate samples were collected from fetal venous perfusate for a period of 30 minutes. Chromium concentration in perfusate samples was determined using atomic absorption spectrophotometry and the concentration of reference marker, antipyrine was measured by spectrophotometry. Transport kinetics and transport parameters of study and reference markers were assessed using well-established parameters. Results: Differential transport rates of chromium and antipyrine in 10 perfusions differed significantly for 10 and 50% efflux fractions (ANOVA test, p < .05) while those of 25, 75, and 90% efflux fractions were not significantly different between the study and reference substances. Chromium transport fraction (TF) averaged 54.9% of bolus dose in 10 perfusions while that of antipyrine averaged 89% of bolus dose, representing 61.80% of reference marker TF. The difference observed in TF values of chromium and antipyrine was statistically significant (Student's t-test, p < .05). Pharmacokinetic parameters such as area under the curve, clearance, absorption rate, elimination rate of chromium compared to reference marker was significantly different (ANOVA test, p < .05) between the study and reference substances. Conclusions: Our studies report for the first time maternal-fetal transport kinetics of chromium in human placenta in vitro. Considering the restricted transfer of this essential trace element from maternal to fetal circulation despite its small molecular weight, we hypothesize an active transport of chromium across the human placental membrane. Further studies relating to placental transport kinetics of this trace element in various pregnancy-related disease states are in progress.

Human placental PPAR-γ and SOX-2 expression in serologically proved toxoplasmosis.

To explore PPAR-γ and SOX-2 transcription factors expression in placenta according to maternal anti-Toxoplasma gondii serological profile during pregnancy and pregnancy outcome. The study included 240 placentas, grouped according to IgM and IgG serostatus and then subgrouped according to pregnancy outcome that varied between miscarriages, premature labour, stillbirth and giving birth to CNS anomaly or apparently healthy neonates. Samples were H&E stained and histopathologically scored blindly. PPAR-γ expression was measured by ELISA, while SOX-2-positive nuclei were stained immunohistochemically to be calculated by ImageJ. The mean pathological score was significantly higher in IgM+ve and IgG rising than IgG-ve and persistent low groups. Former groups showed significantly higher PPAR-γ (mean = 258.63, 227.11). However, PPAR-γ was higher in apparently healthy neonate subgroups. SOX-2 was significantly lower in IgM+ve and IgG rising groups (mean = 12.87, 43.13) and associated with obvious fibrosis. SOX-2 lowest count was in CNS anomaly subgroup. PPAR-γ and SOX-2 changes may give clues of how Toxoplasma induces pathogenesis during vertical transmission. Triggering PPAR-γ expression may be a tool to downregulate the inflammatory response and establish a metabolically permissive cellular environment for Toxoplasma persistence. Low SOX-2 is suspected to disturb placental mesenchymal stem cells pluripotency and neuroectoderm development.

Atlas-based knee osteophyte assessment with ultrasonography and radiography: relationship to arthroscopic degeneration of articular cartilage.

OBJECTIVES: To investigate intra- and inter-reader agreement of ultrasonography (US) and conventional radiography (CR) for the evaluation of osteophyte presence and size within the tibiofemoral joint. In addition, to correlate these findings with arthroscopic degeneration of the articular cartilage. METHOD: Forty adult patients with knee pain were enrolled in this study. Knee CR and US scanning of the medial and lateral bone margins were performed on all patients. A novel atlas for the US grading of knee osteophytes was used in the evaluation. The number and size of the osteophytes were evaluated semi-quantitatively in two rounds from both the CR images (four readers) and the US images (14 readers). The Noyes grading system was used for the evaluation of arthroscopic degeneration of the articular cartilage in 26 patients. RESULTS: On average, intra- and inter-reader US and CR agreement was substantial and comparable to each other (κ = 0.60-0.72). US detected more osteophytes than CR at both the medial (65% vs. 48%) and lateral (70% vs. 60%) compartments. A statistically significant correlation between CR- or US-based osteophyte and arthroscopy grades was observed only for US at the medial compartment (rs = 0.747, p < 0.001). CONCLUSIONS: The detection of knee osteophytes using the novel US atlas is as reproducible as reading conventional radiographs. US is more sensitive to detect knee osteophytes than CR. Furthermore, osteophytes detected with US correlate significantly with arthroscopic cartilage changes at the medial knee compartment whereas those detected by CR do not.

Adverse pregnancy outcome among teenagers: a reality?

The objective of this retrospective analysis was to evaluate maternal, fetal and neonatal outcomes in primi-adolescent pregnancies in Kuwait. Case records of primigravidae under 29 years of age, attending the antenatal clinic at our tertiary hospital, between January 2002 and December 2010, were analysed. The study group (up to 19 years of age at first pregnancy) consisted of 3,863 women and the control group (20-29 years of age at first pregnancy) comprised of 4,416 women. Maternal obstetric, fetal and neonatal complications were compared between the groups. Rates of ectopic pregnancy, pre-eclampsia, eclampsia, preterm labour, premature rupture of membrane and caesarean section were significantly higher among adolescents < 15 years of age; the risk then decreased steadily with age and became comparable with the control group after 16 years of age.

Cervical tracheal resection with cricotracheal anastomosis: experience in adults with grade III-IV tracheal stenosis.

INTRODUCTION: Laryngotracheal stenosis is currently one of the most common complications associated with nasal and orotracheal intubation and tracheotomy. Once established, tracheal stenosis can be a complex and difficult problem to manage. PATIENTS AND METHODS: We retrospectively analysed 2004-2010 data for 12 male patients with postintubation cervical tracheal stenosis (grade III-IV) treated in the otolaryngology department, Mansoura University Hospitals. All patients had a tracheostomy at presentation, and all underwent tracheal resection with primary cricotracheal anastomosis and suprahyoid release. RESULTS: Grade III stenosis was present in five patients (41.7 per cent) and grade IV stenosis in seven patients (58.3 per cent). The length of trachea resected ranged from 2 to 4 cm, representing one to four tracheal rings. In all 12 patients, the procedure allowed successful tracheotomy decannulation. Minor complications comprised surgical emphysema (n = 2) and wound infection (n = 1), and were managed conservatively. Major complications consisted of restenosis (n = 3), managed in two patients by repeated dilatation; one patient was lost to follow up. CONCLUSION: Segmental tracheal resection with cricotracheal anastomosis was successful in 11/12 (92 per cent) patients with severe cervical tracheal stenosis. The strategy for treatment of airway stenosis is now well established and success rates are high, with minimal or no sequelae.

Molecular cloning, characterization, expression pattern and cellular distribution of an ovarian lipophorin receptor in the cockroach, Leucophaea maderae.

A cDNA that encodes a lipophorin receptor (LpR) with a predicted structure similar to that of the low density lipoprotein receptor (LDLR) gene superfamily was cloned from ovaries of the cockroach, Leucophaea maderae (Lem) and characterized. This is the first LpR sequenced from the order Dictyoptera. The cDNA has a length of 3362 bp coding for an 888-residue mature protein with a predicted molecular mass of ~99.14 kDa and a pI value of 4.68. The deduced amino acid sequence showed that the LemLpR harbours eight ligand-binding repeats (LBRs) at the N-terminus similar to the other insect LpRs, and thus resembles vertebrate VLDLRs. In addition to eight tandemly arranged LBRs, the five-domain receptor contains an O-linked sugar region and the classic LDLR internalization signal, FDNPVY. Northern blot analysis revealed the presence of ~4.0 kb ovarian mRNA that was transcribed throughout oogenesis with its peak especially during late previtellogenic and vitellogenic periods (from days 3 to 11). LpR transcript(s) or homologues of LDLRs were also detected in the head, midgut, Malpighian tubules, muscles and in the fat body. RNA in situ hybridization and immunocytochemistry localized the LpR mRNA and protein to germ line-derived cells, the oocytes, and revealed that LpR gene transcription and translation starts very early during oocyte differentiation in the germarium. LpR protein was evenly distributed throughout the cytoplasm during previtellogenic periods of oogenesis. However, during vitellogenic stages, the receptor was accumulated mainly in the cortex of the oocyte. Immunoblot analysis probed an ovarian LpR protein of ~115 and 97 kDa under reducing and nonreducing conditions, respectively. The protein signal appeared on day 2, increased every day and was high during vitellogenic periods from day 4 to day 7. Southern blot analysis suggested the presence of a single copy of the LpR gene in the genome of Le. maderae.

Insulinoma in Saudi Arabia: a twenty-year hospital study.

The study was designed to assess retrospectively clinical pattern of insulinoma at a national referral center in the Kingdom of Saudi Arabia. All cases of insulinoma recorded at King Khalid University Hospital Riyadh between January 1987 and December 2006 were reviewed. During the 20-year period five patients were seen comprising three females (ages 38, 40, and 70 years) and two males (17 and 34 years). The duration of symptoms prior to diagnosis ranged between one and eight years. The commonest mode of presentation before diagnosis was inability to observe Ramadan fasting. Other notable symptoms included dizziness and loss of consciousness. All the five patients proceeded to operation. At surgery all were found to be benign tumors. Post-operatively, three of the patients developed pseudocyst, which resolved upon undergoing second surgery. Though clinical presentation of insulinoma in Saudi subjects is similar to those reported in the literature, our study revealed prominent symptoms occurring during yearly ramadan religious fast could be a useful information in history taking. Further studies on a larger population are needed to further characterize our findings.

Insulinoma in Saudi Arabia: a twenty-year hospital study.

The study was designed to assess retrospectively clinical pattern of insulinoma at a national referral center in the Kingdom of Saudi Arabia. All cases of insulinoma recorded at King Khalid University Hospital Riyadh between January 1987 and December 2006 were reviewed. During the 20-year period five patients were seen comprising three females (ages 38, 40, and 70 years) and two males (17 and 34 years). The duration of symptoms prior to diagnosis ranged between one and eight years. The commonest mode of presentation before diagnosis was inability to observe Ramadan fasting. Other notable symptoms included dizziness and loss of consciousness. All the five patients proceeded to operation. At surgery all were found to be benign tumors. Post-operatively, three of the patients developed pseudocyst, which resolved upon undergoing second surgery. Though clinical presentation of insulinoma in Saudi subjects is similar to those reported in the literature, our study revealed prominent symptoms occurring during yearly ramadan religious fast could be a useful information in history taking. Further studies on a larger population are needed to further characterize our findings.

Diagnostic and prognostic utility of t(14;18) in follicular lymphoma.

BACKGROUND: Follicular lymphoma (FL) is one of the most common non-Hodgkin's lymphomas of B cells, being closely associated with a t(14;18) translocation. Detection of t(14;18), which is present in 70-95% of FL, might aid in FL diagnosis. OBJECTIVE: To compare the efficacy of routine polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) techniques in detecting t(14;18) in paraffin-embedded tissue samples of FL patients at different stages. Combined with other immunophenotypic biological determinants, detection of t(14;18) might help to determine patients at increased risk according to the FL International Prognostic Index (FLIPI) and therefore facilitate appropriate treatment. DESIGN AND METHODS: This study was mainly based on a retrospective examination of formalin-fixed, paraffin-embedded lymph nodes. We selected fixed tissue samples of 21 FL patients treated at the National Cancer Institute Center in the period from 2000 to 2001. RESULTS: FISH techniques could detect 14 of 18 FL cases with a sensitivity of 77.8%, while the PCR technique could detect only 11 of 18 FL cases with a sensitivity of 61.1%, resulting in a statistically significant difference between both techniques (p = 0.004). According to the FLIPI index, 9 of the 18 FL patients were categorized into the high-risk group (50%), 5 in the intermediated-risk group (27.8%) and 4 in the low-risk group (22.2%). CONCLUSION: The sensitivity of FISH is superior to that of PCR in the detection of the t(14;18) translocation in paraffin-embedded tissue samples. There is a statistically significant correlation between both CD10 and FISH with FLIPI.