A Varactor-Based Very Compact Tunable Filter with Wide Tuning Range for 4G and Sub-6 GHz 5G Communications.

A very compact microstrip reconfigurable filter for fourth-generation (4G) and sub-6 GHz fifth-generation (5G) systems using a new hybrid co-simulation method is presented in this manuscript. The basic microstrip design uses three coupled line resonators with λ/4 open-circuited stubs. The coupling coefficients between the adjacent and non-adjacent resonators are used to tune the filter at the required center frequency to cover the frequency range from 2.5 to 3.8 GHz. The coupling coefficient factors between the adjacent resonators are adjusted to control and achieve the required bandwidth, while the input and output external quality factors are adjusted to ensure maximum power transfer between the input and output ports. Two varactor diodes and biasing circuit components are selected and designed to meet the targeted performance for the tunable filter. The impedance bandwidth is maintained between 95 and 115 MHz with measured return losses of more than 17 dB and measured insertion loss of less than 1 dB. Computer simulation technology (CST) is utilized to design and optimize the presented reconfigurable filter, with hybrid co-simulation technique, using both CST microwave studio (MWS) and CST design studio (DS), is applied to build the model by considering the SPICE representation for the varactor switches and all electronic elements of the biasing circuit. The introduced reconfigurable microstrip filter is also fabricated using a Rogers RO3010 material with a relative dielectric constant of 10.1 and it is printed on a very compact size of 13 × 8 × 0.81 mm3. An excellent agreement is obtained between the simulation and measurement performance.

Nephronophthisis and retinal degeneration in tmem218-/- mice: a novel mouse model for Senior-Løken syndrome?

Mice deficient in TMEM218 (Tmem218(-/-) ) were generated as part of an effort to identify and validate pharmaceutically tractable targets for drug development through large-scale phenotypic screening of knockout mice. Routine diagnostics, expression analysis, histopathology, and electroretinogram analyses completed on Tmem218(-/-) mice identified a previously unknown role for TMEM218 in the development and function of the kidney and eye. The major observed phenotypes in Tmem218(-/-) mice were progressive cystic kidney disease and retinal degeneration. The renal lesions were characterized by diffuse renal cyst development with tubulointerstitial nephropathy and disruption of tubular basement membranes in essentially normal-sized kidneys. The retinal lesions were characterized by slow-onset loss of photoreceptors, which resulted in reduced electroretinogram responses. These renal and retinal lesions are most similar to those associated with nephronophthisis (NPHP) and retinitis pigmentosa in humans. At least 10% of NPHP cases present with extrarenal conditions, which most often include retinal degeneration. Senior-Løken syndrome is characterized by the concurrent development of autosomal recessive NPHP and retinitis pigmentosa. Since mutations in the known NPHP genes collectively account for only about 30% of NPHP cases, it is possible that TMEM218 could be involved in the development of similar ciliopathies in humans. In reviewing all other reported mouse models of NPHP, we suggest that Tmem218(-/-) mice could provide a useful model for elucidating the pathogenesis of cilia-associated disease in both the kidney and the retina, as well as in developing and testing novel therapeutic strategies for Senior-Løken syndrome.

Arsenic levels in tube-wells water, food, residents' urine and the prevalence of skin lesions in Yatenga province, Burkina Faso.

The aim of the present study was to evaluate the levels of arsenic in tube-well water, food and residents' urines samples in Yatenga province, Burkina Faso. The prevalence of skin lesions was evaluated as well. The study was cross-sectional in design. It was conducted during April 2009. Permanent residents of 20 villages were included in the study. Water samples were collected from 31 tube-wells located in the selected villages. Tomatoes, cabbages, and potatoes produced in the selected village were randomly sampled. Arsenic content in water, food, and residents' urine was determined by atomic absorption spectrophotometry using hydride generation method. Finally, 240 people were examined by a medical doctor for skin lesions. Arsenic concentrations from the tube-well water ranged from 1 to 124 µg/l. Arsenic concentrations of more than one-half (52%) of the water samples exceeded the WHO guideline value (10 µg/l). No trace of arsenic was found in the samples of tomatoes, cabbages, and potatoes. Variation in arsenic concentrations in the urines was correlated to arsenic concentrations in tube-well water. Clinical examinations revealed that melanosis and keratosis were respectively identified in 29.26% and 46.34% of the population. Both conditions were observed in 24.39% of the population. The frequency of skin lesions was positively associated with the arsenic concentration in tube-well water. A great majority (89.53%) of those who had skin lesions were at least 18 years old. In conclusion, chronic arsenic poisoning remains a major public health problem in the province of Yatenga (Burkina Faso).

The positive impact of red palm oil in school meals on vitamin A status: study in Burkina Faso.

BACKGROUND: Vitamin A (VA) deficiency is widespread in sub-Saharan Africa and school-age children are a vulnerable group. In Burkina Faso, the production and consumption of red palm oil (RPO) is being promoted as a food supplement for VA. The objective of the study was to assess the impact on serum retinol of adding RPO to school lunch in two test zones of Burkina Faso. METHODS: Over one school year, 15 ml RPO was added to individual meals 3 times a week in selected primary schools in two sites. Serum retinol was measured with HPLC at baseline and exactly 12 months later to take account of seasonality. A simple pre-post test design was used in the Kaya area (north-central Burkina), where 239 pupils from 15 intervention schools were randomly selected for the evaluation. In Bogandé (eastern Burkina), 24 schools were randomised for the controlled intervention trial: 8 negative controls (G1) with only the regular school lunch; 8 positive controls (G2) where the pupils received a single VA capsule (60 mg) at the end of the school year; and 8 schools with RPO through the school year (G3). A random sample of 128 pupils in each school group took part in the evaluation. RESULTS: In Kaya, serum retinol went from 0.77 +/- 0.37 micromol/L at baseline to 1.07 +/- 0.40 micromol/L one year later (p < 0.001). The rate of low serum retinol (< 0.7 micromol/L) declined from 47.2% to 13.1%. In Bogandé, serum retinol increased significantly (p < 0.001) only in the capsule and RPO groups, going from 0.77 +/- 0.28 to 0.98 +/- 0.33 micromol/L in the former, and from 0.82 +/- 0.3 to 0.98 +/- 0.33 micromol/L in the latter. The rate of low serum retinol went from 46.1 to 17.1% in the VA capsule group and from 40.4% to 14.9% in the RPO group. VA-deficient children benefited the most from the capsule or RPO. Female sex, age and height-for-age were positively associated with the response to VA capsules or RPO. CONCLUSION: RPO given regularly in small amounts appears highly effective in the reduction of VA deficiency. RPO deserves more attention as a food supplement for VA and as a potential source of rural income in Sahelian countries.

The relationship between human papillomavirus and p53 gene in conjunctival squamous cell carcinoma.

PURPOSE: The p53 tumor-suppressor gene has been documented to exist in mutated forms in many types of squamous cell carcinoma in the body. Also in conjunctival squamous cell carcinoma, human papillomavirus (HPV) is accepted as an oncogenic factor. The objective of our study was to establish a correlation between p53 overexpression and the presence of HPV infection within tumor tissues from patients with conjunctival squamous cell carcinoma. METHODS: Tissue sections obtained from paraffin-embedded conjunctival squamous cell carcinoma specimens from 23 patients were examined with light microscopy, polymerase chain reaction (PCR), and immunohistochemistry. RESULTS: Seventy-eight percent of tumors were positive for p53, whereas 22% were positive for HPV. The proportion of patients positive for both p53 and HPV was 17%, whereas another 17% of the patients were negative for both p53 and HPV. Therefore no significant disproportion was found in the distribution of patients' HPV status and p53 status (p = 1.00). No significant correlation or linear association was found between the HPV status and p53 status (r = 0.022; p = 0.920). CONCLUSION: We could not show any statistical association between abnormal p53 gene-product expression by immunohistochemistry in conjunctival squamous cell carcinomas and HPV infection by PCR detection techniques.

Nasolacrimal tuberculosis in a patient with conjunctivodacryocystorhinostomy.

PURPOSE: To present an unusual case of nasolacrimal tuberculosis that was diagnosed with polymerase chain reaction (PCR) and to discuss the role of PCR as a diagnostic aid. METHODS: Case presentation with diagnostic modalities including PCR, cytopathologic, and histopathologic examinations with special stains. RESULTS: A 40-year-old woman with bilateral lacrimal drainage system obstruction underwent a right dacryocystorhinostomy with stents and left conjunctivodacryocystorhinostomy with Jones bypass tube. Although the findings of direct and endoscopic examinations of the nasal cavity were within normal limits, the tissue removed during surgery from the middle turbinate revealed caseating granulomatous lesions on histopathologic examination. Acid-fast organisms were demonstrated in postoperative nasal washings, and Mycobacterium tuberculosis infection was confirmed with PCR. CONCLUSION: Primary tuberculosis of the nasolacrimal mucosa is rare, and its occurrence without any symptoms, as in this patient, is even less frequent. The most interesting aspect of this case was the identification of the M. tuberculosis DNA in the mucosa of anterior turbinate and fibrous tissue within the previous surgical site. Histopathologically, the presence of caseating granulomas was seen only in the nasal mucosa, indicating that PCR may be of use in identifying the causative organism even in the absence of typical histopathologic features.

Human papilloma virus in neoplastic and non-neoplastic conditions of the external eye.

AIM: Human papilloma virus (HPV) types 16 and 18 have been associated with neoplastic conditions of the conjuctiva. However, the presence of this virus has not been reported in non-neoplastic disorders of the external eye nor has it been studied in normal conjunctival tissues. METHODS: Ninety six paraffin embedded tissue specimens with neoplastic and non-neoplastic lesions and 19 conjunctiva samples free from overt disease were studied for HPV types 16 and 18 positivity with the polymerase chain reaction. RESULTS: HPV types 16 and 18 DNA were identified in 57% of in situ squamous cell carcinoma, in 55% of invasive squamous cell carcinoma, in 20% of climatic droplet keratopathy, in 35% of scarred corneas, and in 32% of normal conjunctival tissue obtained during routine cataract extractions. CONCLUSION: These findings indicate that HPV types 16 and 18 are detectable with the polymerase chain reaction not only in epithelial neoplasms of the ocular mucous membrane but also in non-neoplastic lesions as well as in apparently healthy conjunctiva.

[Primary multiple tumors of the larynx]. / Pervichno-mnozhestvennye opukholi gortani.

A rare combination of two histogenetically different tumours of the larynx in a male patient of 43, namely chondrosarcoma and squamous cell carcinoma is described. These tumours developed simultaneously, therefore the carcinoma could not result from the radiotherapy. No similar observation has been published in the literature.

Assignment of the NRAS protooncogene to chromosome 12 of Syrian hamster by in situ hybridization.

The NRAS protooncogene codes for a GTP binding/GTPase p21 protein which resides on the inner surface of the plasma membrane. Using a human cDNA probe for NRAS, we have assigned the gene to Syrian hamster chromosome 12 with the most likely localization being 12qa5.

Tissue reaction to prosthetic materials in human temporal bones.

We studied tissue reaction to polymeric silicone (Silastic), polyethylene, tantalum wire, and polytetrafluorethylene (Teflon) in temporal bones and to Silastic in removed shunt tubes. A purpose of this study was to determine which synthetic material is best for insulation of cochlear implant electrodes. We found fibrous tissue around all shunt tubes and in all bones, giant cells in some specimens, and lymphocytic infiltration in a few. We consider none of these findings to indicate bioincompatibility, except in one case with a presumed idiosyncratic reaction to Silastic. We conclude that all four materials are well tolerated by the human ear. Our finding that Silastic is well tolerated for long periods of time leads us to conclude that it is good choice for insulation for implanted wires.

The effect of stapedectomy on hearing of patients with otosclerosis and Meniere's disease.

To determine new guidelines for stapedectomy in patients with both Meniere's disease and otosclerosis, we studied the position of the saccular membrane and Reissner's membrane in relation to the stapes footplate in eight temporal bones from patients with Meniere's disease. We also reviewed charts of four patients with both otosclerosis and Meniere's disease who had stapedectomy. Histologic and clinical findings were compared with preoperative bone conduction levels at 500 Hz and at high frequencies. We found that the saccular and Reissner's membranes did not contact the stapes footplate ain bones of patients with preoperative bone conduction levels of 35 dB or better at 500 Hz and no high-frequency loss. We also found that stapedectomy was successful in patients with the same criteria. We therefore conclude that stapedectomy does not increase the risk of sensorineural hearing loss for patients with otosclerosis and Meniere's disease who have bone conduction levels of 35 dB o better at 500 Hz and no high-tone loss, but it is contraindicated for patients with 45 dB at 500 Hz or worse and with high-tone loss.