Photonic metacrystal: design methodology and experimental characterization.

We report a design methodology for creating high-performance photonic crystals with arbitrary geometric shapes. This design approach enables the inclusion of subwavelength shapes into the photonic crystal unit cell, synergistically combining metamaterials concepts with on-chip guided-wave photonics. Accordingly, we use the term "photonic metacrystal" to describe this class of photonic structures. Photonic metacrystals exploiting three different design freedoms are demonstrated experimentally. With these additional degrees of freedom in the design space, photonic metacrystals enable added control of light-matter interactions and hold the promise of significantly increasing temporal confinement in all-dielectric metamaterials.

Quasi-Static Pull-in: an Instability in Electrostatic Actuators.

We identify a new instability in electrostatic actuators dubbed quasi-static pull-in. We report experimental evidence of the instability and study its characteristics in two types of micro actuators operating in ambient air. We found that the underlying mechanism is a fast-slow dynamic interaction between slowly-varying electrostatic excitation and fast resonator response that instigate large non-resonant oscillatory orbits and eventually disappears in a global Shilnikov bifurcation. Based on these findings, we formulate and present a new taxonomy of pull-in instabilities in electrostatic actuators.

Psychiatric Disorders among Prisoners: A National Study in Egypt.

OBJECTIVES: To estimate the overall prevalence of psychiatric disorders among prisoners and its associated factors, and to estimate the prevalence of different mental and personality disorders. METHODS: This was a cross-sectional descriptive study carried out in 16 randomly selected prisons in Egypt. A stratified proportional random sample of 1350 adult prisoners was included in the study. Data were collected by a psychiatrist by direct interview with prisoners. The study questionnaire obtained information about socio-demographics, prisoner circumstances, medical history, psychological factors, legal history of the prisoner as well as the Arabic version of the Structured Clinical Interview for the DSM-IV Axis I and Axis II disorders. Bivariate and logistic regression analyses were performed to determine the significant factors associated with presence of psychiatric disorder. RESULTS: The overall point prevalence of psychiatric disorders was 22%, excluding substance abuse and alcohol intake. The independent predictors for psychiatric disorders were work in prison (adjusted odds ratio = 0.6), family visits (0.5), substance abuse outside prison (2.7), history of psychiatric disorders outside prison (2.0), and repeated admission to the prison (2.5). The prevalence of mood disorders and psychosis was 3.3% and 1.3%, respectively. The overall prevalence of personality disorders was 13.6%. CONCLUSIONS: Psychiatric disorders are prevalent among prisoners; the most common being personality and antisocial disorders. There is a need for psychiatric assessment of prisoners when first imprisoned and for subsequent regular monitoring and treatment.

Dynamic potential and surface morphology study of sertraline membrane sensors.

New rapid, sensitive and simple electrometric method was developed to determine sertraline hydrochloride (Ser-Cl) in its pure raw material and pharmaceutical formulations. Membrane sensors based on heteropolyacids as ion associating material were prepared. Silicomolybdic acid (SMA), silicotungstic acid (STA) and phosphomolybdic acid (PMA) were used. The slope and limit of detection are 50.00, 60.00 and 53.24 mV/decade and 2.51, 5.62 and 4.85 µmol L(-1) for Ser-ST, Ser-PM and Ser-SM membrane sensors, respectively. Linear range is 0.01-10.00 for the three sensors. These new sensors were used for the potentiometric titration of Ser-Cl using sodium tetraphenylborate as titrant. The surface morphologies of the prepared membranes with and without the modifier (ion-associate) were studied using scanning and atomic force microscopes.

Distributed electrode Mach-Zehnder modulator with double-pass phase shifters and integrated inductors.

A novel high-speed Mach-Zehnder modulator (MZM) fully integrated into a 90 nm CMOS process is presented. The MZM features 'double-pass' optical phase shifter segments, and the first use of integrated inductors in a 'velocity-matched' distributed-electrode configuration.

Surface morphology changes of polymer membrane and carbon paste sertraline sensors.

Polymer membrane and chemically modified carbon paste (CMCP) sensors for determination of sertraline HCl (Ser-Cl) incorporating sertraline tetraphenylborate (Ser-TPB) as an electro-active material were constructed. They showed a rapid and linear response for Ser-ion over the concentration range 0.01-10.00 mmol L(-1). The limits of detection were 2.80 and 9.55 µmol L(-1), and Nernastian slopes were 56.60, 59.60 mV decade(-1) for membrane and CMCP sensors for batch method. In flow injection analysis (FIA), the electrodes revealed comparatively good selectivity for Ser-ion with regard to a wide variety of different cations, sugars, and amino acids. The addition of different anionic additives, namely sodium tetraphenylborate (NaTPB), potassium tetraphenylborate (KTPB), potassium tetrakis[3,5-bis-(triflouromethyl)phenyl]borate (KTFMPB), and sodium tetrakis[3,5-bis(trifluoro-methyl)phenyl]borate (NaTFMPB), to the prepared mixture improved their response characteristics. The surface morphologies of membrane films containing PVC only (blank), plasticizer+PVC, Ser-TPB+plasticizer+PVC, and Ser-TPB +plasticizer+PVC+additive were studied using scanning and atomic force electron microscopes. These sensors had been used in the potentiometric titration of Ser-ion against NaTPB. Standard addition method for the pure raw material and some of its pharmaceutical tablets was used for Ser-Cl determination. The obtained results were tested for their repeatability and reproducibility and were statistically treated by F- and t- tests.

The mosquito borne West Nile virus infection: is it threating to Egypt or a neglected endemic disease?

West Nile virus (WNV) is a mosquito-borne zoonotic arbovirus belonging to the genus Flavivirus in the family Flaviviridae. The virus is found in temperate and tropical regions worldwide, but first identified in the West Nile sub-region in the East African nation of Uganda in 1937. Prior to the mid-1990s WNV infection was sporadically and considered a minor risk for humans, until an outbreak in Algeria in 1994, with cases of WNV-caused encephalitis, and the first large outbreak in Romania in 1996; with a high number of cases with neuroinvasive disease. WNV has now spread globally to Europe beyond the Mediterranean Basin and the United States, is now considered to be an endemic pathogen in worldwide especially in Africa The WNV transmission is mainly b y v a rious mosquitoes species, also tickswere incriminated The birds especially passerines are the most commonly infected animal and serving as the prime reservoir host In Egypt more than 110 mosquito species and subspecies and more than 32 genera of ticks were identified. Besides, not less than 150 species of migratory birds visit Egypt annually in addition to 350 resident ones. This review provided an overview of the current understanding flaviviruses mainly WNFV. Primary care physician and senior nurse should be able to include the disaster diseases in differential diagnosis of various clinical conditions. They should take a thorough history to request specific dependable laboratory test(s) as soon as possible, and positive patient should be transferred to the fever hospital.

Single and mixed chemically modified carbon paste ion-selective electrodes for determination of ketotifen fumarate.

New modified carbon paste electrodes for determination of ketotifen fumarate in its pure and pharmaceutical preparations were constructed. The used modifiers are ketotifen phosphotungestate (Keto(3) PT), and ketotifen tetraphenylborate (Keto-TPB). Single and mixed ion-associate electrodes were prepared. Both Keto-TPB and mixed (Keto-TPB and Keto(3) PT) electrodes have a linearity range of 1.00 × 10(-5) -1.00 × 10(-2) mol L(-1) . The slopes were 58.30 and 54.20 mV/decade for Keto-TPB and mixed chemically modified carbon paste electrodes (CMCPE), respectively. The limits of detection were 1.42 × 10(-6) and 1.00 × 10(-5) mol L(-1) for Keto-TPB and mixed CMCPEs, respectively. The potential variation due to pH change is considered acceptable in the pH ranges 4.44-9.11 and 2.50-9.00 for Keto-TPB and mixed ion-exchanger CMCPE, respectively. The response time was ≤10 s for both electrodes. Selectivity coefficients values towards different inorganic cations, sugars, and amino acids reflect high selectivity of the prepared electrodes. Potentiometric titrations and standard addition methods were applied for the determination of ketotifen ion in its pure samples and pharmaceutical formulations (Zaditen tablet and syrup) using proposed electrodes. The electrodes were also tested in flow injection analysis (FIA). The results obtained from both methods were statistically treated by F- and t-tests. The carbon paste electrodes have the advantages of being more easily prepared and longer life span compared to the plastic membrane electrodes previously reported.

Nutritional status in older adults with mild cognitive impairment living in elderly homes in Cairo, Egypt.

OBJECTIVES: To delineate the difference in nutritional risk between older adults with normal cognitive function and mild cognitive impairment living in elderly homes. DESIGN: Cross-sectional study. SETTING: Three elderly homes in Cairo, Egypt. PARTICIPANTS: One hundred twenty older adults; men and women aged 60 years and older. MEASUREMENTS: Comprehensive geriatric assessment was done for every participant to evaluate medical, functional, cognitive and affective aspects. Nutritional status was assessed by using the mini-nutritional assessment (MNA). Nutritional deficit was considered to be present if the individuals were classified as malnourished or at nutritional risk by means of the MNA. The cognitive function was assessed by using the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). RESULTS: MCI was identified in 46 (38.3%) of the participants. According to the MNA classification, 58 (48.3%) of the sample study was assessed as well nourished, 49 (40.8%) at risk of malnutrition and 13 (10.8%) as malnourished. Older adults with MCI had significantly higher frequency of being at risk of malnutrition or malnourished than those with normal cognition. Multiple logistic regression analysis revealed that the associations between MCI and nutritional deficit remained significant after adjustment for age, illiteracy, female gender and depression. CONCLUSION: These results suggest that MCI may be associated with nutritional risk, which emphasizes the importance of early identification of nutritional status among individuals with MCI. It remains to be demonstrated whether improvement in nutritional status may improve the cognitive function or delay progression to dementia in these patients.

Flow injection determination of ketotifen fumarate using PVC membrane selective electrodes.

In this study a PVC membrane electrode for determination of ketotifen fumarate is reported, where ketotifen tetraphenylborate (Keto-TPB) was used as ion exchanger. The electrode has linear range of 5.6x10(-6)-1.0x10(-2) and 1.0x10(-5)-1.0x10(-2) mol/L, with detection limits 2.37x10(-6)and 4.60x10(-6) mol/L in batch and flow injection analysis (FIA), respectively. The electrodes show a Nernstian slope value (58.40 and 61.50 mV/decade in batch and FIA, respectively), and the response time is very short (

Laparoscopic versus open appendectomy: a prospective comparative study of 227 patients.

BACKGROUND: Although laparoscopic appendectomy is widely practiced in developed countries, still there are many questions regarding the advantages and disadvantages of this approach in the treatment of acute appendicitis. Several controlled trials have been conducted, some in favor of laparoscopic appendectomy others not. The aim of this study was to evaluate laparoscopic appendectomy in comparison with open appendectomy, with special emphasis on postoperative septic complications. METHODS: For this study, 227 consecutive patients (159 males and 68 females) with a diagnosis of suspected appendicitis between 1995 and 1999 were assigned either to laparoscopic appendectomy (n = 108) or open appendectomy (n = 119). The patients were assigned according to insurance company approval and patient preference. There were no exclusion criteria and no age limits in this study. RESULTS: Wound infection was significantly higher in the open group (incidence, 7.6%) than in the laparoscopic group (incidence, 0%; p <0.003). Intraabdominal infections were equal in both groups. Hospital stay was significantly shorter in the laparoscopic group (p <0.046), but operative time was little longer than in the open group (p <0.002). Conversion to open surgery was necessary in one case. CONCLUSIONS: Laparoscopic appendectomy is as safe and effective as the open procedure. It significantly reduces the rate of postoperative wound infection. However, it is still acceptable to perform the open procedure, especially in hospitals without a large amount of laparoscopic experience.

Evaluation of the protective potential of Ambrosia maritima extract on acetaminophen-induced liver damage.

The hepatoprotective activity of the aqueous-methanolic extract of Ambrosia maritima was investigated against acetaminophen (paracetamol, 4-hydroxy acetanilide) induced hepatic damage. Acetaminophen at the dose of 640 mg/kg produced liver damage in rats as manifested by the significant (P < 0.001) rise in serum levels of glutamate oxaloacetate transaminase (AST), glutamate pyruvate transaminase (ALT) and alkaline phosphatase (ALP) to 1178.5 +/-118.05; 607.5 +/- 32.6 and 274.16 +/- 8.89 IU/l (n = 10), respectively, compared with respective control values of 97.83+/-3.23; 46.0 +/- 3.92 and 168.67 +/- 7.86 IU/l. Pretreatment of rats with the plant extract (100 and 200 mg/kg) lowered significantly (P < 0.001) the respective serum AST to 203.3+/-5.74 and 157.1 +/- 8.78 IU/l, ALT to 138.67 +/- 7.7 and 87.5 +/- 3.6 IU/l and ALP levels to 238.0 +/- 5.89 and 206.5 +/- 7.5 IU/l, respectively. Treatment of rats with acetaminophen led to a marked increase in lipid peroxidation as measured by malondialdehyde (MDA) (42%). This was associated with a significant reduction of the hepatic antioxidant system e.g. reduced glutathione (GSH) (65%), glutathione reductase (GSH-R) (35%), total glutathione peroxidase (GSH-Px) (32%) and glutathione-S-transferase (GST) (16%). These biochemical alterations resulting from acetaminophen administration were inhibited by pretreatment with A. maritima L. extract. These data suggest that the plant A. maritima L. may act as a hepatoprotective and antioxidant agent.

Bacterial meningitis in Saudi children.

During the four years period from 1988 to 1991, 50 pediatric patients were diagnosed to have bacterial meningitis, out of a total number of 9057 pediatric admissions at Qatif Central Hospital, Qatif, Saudi Arabia, and 82% were less than two years of age. The causative organisms were isolated in 27 (54%) patients. The bacteria grown included Haemophilus influenzae type B in 8 patients (29.6%), Neisseria meningitidis in 8 patients (29.6%), Streptococcus pneumonia in 6 (22%) patients, and other bacteria in 5 patients (18.5%). Cerebro spinal fluid cultures from twenty three patients (46%) showed no organisms, however their clinical and C.S.F. findings were compatible with bacterial meningitis. One case of H. influenzae type B was resistant to ampicillin. Six patients died with an over all mortality of 12%, and 10 patients (20%) developed some kind of C.N.S. sequelae. Partially treated meningitis formed a large percentage of our sample.

Incidence of major infection in sickle cell pediatric patients at Qatif Central Hospital.

During the two-year period, 20 Jumada I 1408 (January 9, 1989) to 20 Jumada I 1410 (December 18, 1989), a total of 450 pediatric patients with sickle-cell anemia were admitted to the pediatric ward of Qatif Central Hospital. Thirty-nine patients had a major infection (septicemia, meningitis, or osteomyelitis), with an incidence of 8.6%. During the same period, 3700 non-sickle pediatric patients were admitted and 38 of them had a major infection, with an incidence of 1% (P<0.001). Three patients died in the sickle cell groups, for a case fatality rate of 7.6%, while only one patient in the control group died, for a case fatality rate of 2.6% (P<0.002). Salmonella species were responsible for 12 cases of septicemia and three episodes of osteomyelitis, and Streptococcus pneumoniae was the source in eight cases of septicemia and one case of meningitis in sicklers. Meningitis was caused by different organisms, such as Streptococcus pneumoniae, Salmonella, and Meningococcus. Antibiotics that cover both Salmonella and Streptococcus pneumoniae must be considered in all children with sickle cell anemia who have a febrile illness.

Natural killer cell regulation of age-related and type-specific variations in antibody responses to pneumococcal polysaccharides.

Pretreatment of mice with anti-asialo GM1, which has been shown to deplete NK cytolytic activity without affecting cytotoxic T cells or macrophages, increased the weak anti-PPS 6 responses of adult mice to levels similar to that of their anti-PPS 3 responses, and increased the weak-to-absent anti-PPS 3 and anti-PPS 6 responses of weanling mice to the same levels as achieved by adult mice. By contrast, pretreatment with poly(IC), which augments NK activity, resulted in a 14-fold reduction in the anti-PPS 3 responses of adult mice. The enhancement of anti-PPS responses in mice treated with anti-asialo GM1 was due to inactivation or depletion of NK cells, and not T suppressor cells, since this enhancement occurred in athymic nude mice as well as in euthymic mice. In addition, strains of mice with low or absent endogenous NK activity were found to have considerably stronger anti-PPS responses than strains of mice with normal NK activity. NK depletion enhanced anti-PPS 6 IgM but not IgG response, and resulted in a true increase in antibody production rather than an alteration in the time course of the response. These findings indicate that NK cells physiologically downregulate anti-PPS responses, and that age-dependent and type-specific variations in these responses are primarily determined by NK regulatory effects.