EPI System Research Articles

Experimental study of the influence of phenozanic acid and its combination with valproic acid on the development of the epileptic system

To study the effect of phenosanic acid (PA) and its combination with valproic acid (VA) on the development of the Epi system. A model of focal chronic epilepsy in rats was created by applying metallic cobalt to the surface of the sensorimotor area of the cortex. Long-term electrodes were implanted in the sensorimotor cortex of the left and right hemispheres, the hippocampus, and the hypothalamus. The effect of PA (80 mg/kg) and its combination with VA (200 mg/kg) on discharge activity was carried out on the 2nd day and at the stage of generalization of the Epi system - on the 6th day. The stability of the Epi system on day 10 was assessed by provoking the development of epileptic status (Epi status) in response to the administration of thiolactone homocysteine (HMC) at a dose of 5.5 mmol/kg. In rats treated with PA, low discharge activity is observed, which is confirmed by the absence of EEG and motor manifestations of status epilepticus caused by HMC. PA does not suppress paroxysmal activity at the stages of development of the Epi system. VA significantly suppresses paroxysmal activity, but does not affect the formation of new foci of Epi activity in subcortical structures and the contralateral cortex. The epi system of rats treated with VA is characterized by high discharge activity by the 10th day of the experiment and lability to provocation of epi status. The combination of drugs is more pronounced than PA, but less than VA, reduces the numerical characteristics of paroxysmal activity in the brain structures of rats. PA when administered alone, in combination with VA, causes a slowdown in the generalization of convulsive foci of Epi activity and prevents the formation of a stable Epi system. VA, having a pronounced anticonvulsant effect, does not weaken the development of the Epi system in the model of focal cobalt-induced epilepsy.

On a Dirichlet boundary value problem for an Ermakov–Painlevé I equation. A Hamiltonian EPI system

Here, a proto-type Ermakov–Painlevé I equation is introduced and a homogeneous Dirichlet-type boundary value problem analysed. In addition, a novel Ermakov–Painlevé I system is set down which is reducible by an involutory transformation to the autonomous Ermakov–Ray–Reid system augmented by a single component Ermakov–Painlevé I equation. Hamiltonian such systems are delimited

Study of the electrophysiological mechanisms of anticonvulsant action of the original levetiracetam analog the compound GIZH-290

The study used the method of cobalt epilepsy, which allows rats with long-term implanted electrodes in the cortical and subcortical structures of the brain to monitor the dynamics of the formation and migration of Epi-foci for a long time. It was found that in the control at the 1st stage of development of the Epi system, Epi activity is most pronounced in the electrocorticograms of the ipsilateral cortex, and at the 2nd, stable stage of development of the Epi system – in the contralateral cortex and subcortical structures. The compound GIZH-290 (the original structural analogue of levetiracetam) reduces the number of Epi discharges and their duration at the 2nd, stable stage of the development of the Epi system. The target structure of the GIZH – 290 compound was the hippocampus. The compound GIZH -290 selectively statistically significantly reduces both the number and duration of Epi – discharges only in the hippocampus and does not affect the foci of epileptic activity in the ipsi-and contralateral cortex and hypothalamus.

Long-term seropositivity, safety, and impact of inactivated and live, attenuated hepatitis a vaccines in China – A cross-sectional study

BackgroundIn 2008, China introduced live, attenuated hepatitis A vaccine (L-HepA, licensed in 1992) and inactivated hepatitis A vaccine (I-HepA, licensed in 2002) nationwide, and is currently the only country using L-HepA in routine immunization. We assessed seropositivity and its duration following vaccination, safety, and association with hepatitis A incidence and population seroprevalence for I-HepA and L-HepA. MethodsWe obtained seroprevalence data from two nationwide serosurveys (in 1992 and 2014), vaccination status from the 2014 serosurvey, and vaccine safety and disease incidence data from the national surveillance system. We compared long-term HAV seropositivity among vaccine recipients and described safety profiles of both vaccines. We categorized the 31 provinces into those predominately using I-HepA and achieving high coverage (n = 4), those predominately using L-HepA achieving high coverage (n = 4), and those predominately using L-HepA achieving lower coverage (n = 23). We compared population HAV seropositivity, coverage, and disease incidence among the three groups. ResultsOne year after vaccination, seropositivity from I-HepA was significantly higher than from L-HepA (97.8% vs 90.7%), and seropositivity declined to 73.5% for L-HepA and 75.4% for I-HepA after 10 years – not significantly different by vaccine. The annual incidence of serious AEFI was <0.5/100 000 for both vaccines. Prior to licensure of either HepA vaccine, provinces that would go on to predominantly use I-HepA had lower incidences of hepatitis A and lower seropositivity levels to HAV than provinces that would go on to use L-HepA. By 2014, these differences were significantly diminished. Regardless of vaccine selection, all three province groups had lower immunity to HAV among individuals born during the 10 years prior to nationwide vaccine introduction – individuals who were 10 to 24 years old in 2014. ConclusionEvidence of good immunogenicity, safety, and impact on incidence supports continued use of both I-HepA and L-HepA in the EPI system. These results may be useful for countries considering integrating HepA vaccines into their routine programs.

Pharmacists' Perceptions of the Benefits and Challenges of Electronic Product Information System Implementation in Hong Kong: Mixed-Method Study.

BackgroundWith the advancement of technology, more countries are now adopting the use of electronic product information (ePI), which refer to an electronic version of physical product inserts in a semistructured format optimized for electronic manipulation. The successful implementation of ePI has led to advantages and convenience to patients, health care professionals, and pharmaceutical companies in many regions and countries. In the Hong Kong Special Administrative Region (SAR), there is currently no citywide implementation of ePI. The SAR exhibits conditions that would favor the implementation of an ePI system, as well as existing barriers hindering its implementation. However, no study has been performed to examine the specific situation in Hong Kong.ObjectiveThe objective of this study is to explore working pharmacists’ overall perception of ePI and to identify potential challenges to the implementation of an ePI system in Hong Kong.MethodsThis mixed-method study involved a structured survey and interview with practicing pharmacists in Hong Kong. Pharmacists were eligible if they were licensed to practice in Hong Kong, and currently working locally in any pharmacy-related sectors and institutions. Respondents completed a survey to indicate their level of agreement with statements regarding the potential advantages of ePI over paper PI. A structured interview was conducted to gather respondents’ perceived advantages of ePI over paper PI in different aspects, such as professionalism, usability, presentation, and environment, as well as challenges of citywide ePI implementation in Hong Kong. Thematic analysis was adopted to analyze the qualitative data. Grounded theory was used to generate themes and identify specific outcomes.ResultsA total of 16 pharmacists were recruited, comprising 4 community pharmacists, 5 hospital pharmacists, and 7 industrial pharmacists. All of them used electronic platforms at least once per month on average. Respondents identified many flaws in physical package inserts that can potentially be mitigated using ePI. The speed with which drug information can be retrieved and the degree to which the drug information can be readily updated and disseminated were considered the greatest strengths of ePI. The clarity with which ePI present drug information to patients was considered as the weakest aspect of ePI. Many respondents highlighted concerns about the security risks and high cost associated with system maintenance and that certain subpopulations may not be sufficiently computer literate to navigate the ePI system. Respondents also voiced many concerns about the implementation and maintenance of a local ePI system.ConclusionsWe conclude that an ePI system is generally supported by pharmacists but concerns about implementation process and maintenance of the system has been raised. The perceived benefits of ePI gathered from this study, as well as collective evidence from other countries with mature ePI systems, confirm that more efforts should be made to promote optimized development and implementation of an ePI system in Hong Kong.

Technologies for Prediction of Preeclampsia.

The aim of the study was to develop technologies for predicting the development of preeclampsia (PE) based on biomedical and molecular-genetic predictors and the calculation of individual risks for this pregnancy complication.Materials and Methods.The study involved 457 pregnant women. Of them, 147 women had chronic arterial hypertension (CAH); 109 pregnant women had CAH and secondary preeclampsia (PE); 201 patients had PE. The control group consisted of 105 pregnant women without hypertensive disorders or proteinuria. We performed a retrospective analysis of gestation course and labor outcomes, calculated risk factors using the Open Epi system and logistic regression method. Polymorphisms of genes controlling the vascular tone were identified in venous blood.Results.There were identified risk factors for developing PE, including those in women with CAH: chronic pyelonephritis; baseline mean AP above 95 mm Hg and diastolic AP above 80 mm Hg; body mass index over 30; family history of arterial hypertension. The following were identified as additional predictors of PE: perinatal loss; premature labor; spontaneous miscarriage; PE and closed craniocerebral injuries in the past medical history; threatening miscarriage in the first trimester. Additional risk factors for PE in women with CAH were found: lack of regular antihypertensive therapy before pregnancy and in the first trimester; chronic gastritis; first pregnancy; tobacco smoking.Polymorphic variants of the NOS3 (-786)C allele in the genotype in combination with the heterozygous genotype in the AGTR2 1675G/A gene are associated with a high risk of CAH. The presence of alleles NOS3 (-786)T/C and NOS3 (-786)C, as well as a combination of alleles NOS3 (-786)C and NOS3 894G/T, is associated with PE. The presence of alleles AGT 704C, CYP11B2 (-344)T, and GNB3 825T/T in the genotype, both individually and in combination, is a risk factor for the development of PE secondary to CAH. The data obtained made it possible to develop a method for predicting the onset of PE in women with CAH and a model for calculating the individual risk of PE, which formed the basis for a computer program.Conclusion.Calculating the individual risks of PE using the technologies proposed by the authors allows identifying pregnant women belonging to the high-risk group on a timely basis, which ensures high-quality implementation of preventive measures, provides a personalized approach and the possibility to prove the need for additional examination of this category of patients.

THE EPIDEMIOLOGY AND RISK FACTORS FOR MORTALITY OF ADULT WITH COVID-19: A RETROSPECTIVE STUDY.

By the ending of 2019 a new type of coronavirus was identified named SARS-CoV 2, and now known to be the etiological agent of the acute respiratory syndrome coronavirus (SARS-CoV-2). Known as coronavirus 2019 disease or (COVID-19) constitutes a challenge for the world in many unknown aspects and problems in public health. In Ecuador the first reported of a confirmed appeared on February 29 2020, and in March 12 an emergency health status is declared. Objective: To determine the epidemiological characteristics and factors related to death and survival in patients with COVID-19. Design: The study is of transversal retrospective design, the patients chosen were those seen in the respiratory or suspicious of COVID-19 area of Hospital Vozandes Quito between March 2 and April 30. Demographic data and related risk factors for mortality were obtained using the EPI-1 individual form, epidemiological research files, the VI Epi system and electronic promptuary of patients. Results: 250 patients were obtained for this study, 87 of those were confirmed COVID-19, out those eight died and 79 were alive at the ending of the follow up. Regarding the severity of illness, 61% of the patients were classified as mild and 6 % critical (p =&lt;0.001). Elevated values of CRP (OR 1 IC 95% 1.000 – 1.024), age about 55 years old to diagnosis (OR 42,040 IC 95% 36,320 – 47,760) and the presence of hiporexia (OR 24 IC 95% 1.183 – 504.413) were associated with higher mortality levels amongst COVID-19 positive patients. Conclusions The majority of COVID-19 cases showed no serious manifestations, were treated symptomatically and home isolation. Elevated values of CRP and the presence of hiporexia at the diagnosis are factors consistently with death. Future investigations are required to determine the risk factors associated with worst clinical course and prognosis.

Routine immunization services costs and financing in China, 2015

ObjectiveTo estimate the costs of routine immunization (RI) services in China in 2015, to provide objective data relevant to investment in the Expanded Program on Immunization, and to contribute to global data on costing and financing of RI. MethodsThe study was conducted between January and March 2016. We selected 276 villages, 138 townships, 46 counties, and 40 prefectures from 15 provinces as investigation sites at random, stratified by eastern, middle, and western regions. Direct cost items included vaccines, personnel, cold chain, surveillance, communication, training, and supervision at the national, provincial, prefecture, county, township, and village levels. We obtained financial data from governmental and external sources. Indirect costs of RI included parents’ transportation costs and productivity lost due to taking their children for vaccination. ResultsTotal direct costs were $92.42 for each child fully immunized ($4.20/dose), which equates to $1529.55 million per birth cohort. RI costs were higher in the eastern region than in the western region, and higher than that of the central region. Vaccination coverage was positively associated with direct routine immunization costs. The cost of the recommended vaccines was $19.08/child and vaccine only accounted for 20.64% of total costs. Operational cost, including surveillance, communication, training and supervision, was $217.31/child, accounting for 14.21% of total cost. The indirect cost per child was $72.86; the total indirect cost was $1205.83 million for the birth cohort. Government investment in RI accounted for about 70% of total costs. Revenue from sales of private-sector vaccine supported the remaining 30% of RI costs. ConclusionsWhile government financing has increased, some operating costs continue to be provided from revenue generated by sales of Category 2 (private-sector) vaccines to families. China could benefit from bringing new and underutilized vaccines into the EPI system based on evidence that includes routine immunization vaccine and operations costs.

Field Evaluation of an Electrostatic Air Filtration System for Reducing Incoming Particulate Matter of a Hen House

Abstract. As a result of the unprecedented highly pathogenic avian influenza (HPAI) outbreak in the U.S. in 2014-2015, some egg producers in the U.S. started using inlet air filtration to reduce the risk of disease transmission by air into hen houses. The removal efficiency of particulate matter (PM), the carrier of airborne pathogens, by such filtration systems has not been investigated. Therefore, this field study was conducted to evaluate the PM removal efficacy of an electrostatic air filtration system (consisting of a low-grade air filter and an electrostatic particle ionization, or EPI, system) installed at the inlet of a commercial high-rise hen house. The evaluation was performed in two test rounds over a one-year period. Results showed that average PM removal efficiencies in round 1 (spring to summer) and round 2 (late fall to spring) were respectively 66% and 29% for PM1, 66% and 30% for PM2.5, 66% and 31% for PM4, 68% and 36% for PM10, and 68% and 45% for total PM. Removal efficiency became unstable when the EPI system was inactive (i.e., when solely relying on the filter for PM removal). House static pressure and ventilation rate indicated considerable clogging of the filter media by dust accumulation and the need for replacement after ~16 weeks of use in the spring-to-summer sampling period (round 1); however, clogging was not an issue during the entire late fall-to-spring sampling period (24 weeks, round 2). The appearance of the filter changed gradually as dust accumulated with time, which can be captured by image analysis and used to judge filter dirtiness and lifespan. The findings of this field study provide insight into the efficacy of PM removal by such a low-cost air filtration system, which will help egg producers in their decision-making for disease prevention strategies. Keywords: Electrostatic particle ionization, Filtration, Hen house, Particulate matter, Reduction.

Evaluation of an electrostatic particle ionization technology for decreasing airborne pathogens in pigs.

Influenza A virus (IAV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine epidemic diarrhea virus (PEDV) and Staphylococcus aureus are important swine pathogens capable of being transmitted via aerosols. The electrostatic particle ionization system (EPI) consists of a conductive line that emits negative ions that charge particles electrically resulting in the settling of airborne particles onto surfaces and potentially decreasing the risk of pathogen dissemination. The objectives of this study were to determine the effect of the EPI system on the quantity and viability of IAV, PRRSV, PEDV and S. aureus in experimentally generated aerosols and in aerosols generated by infected animals. Efficiency at removing airborne particles was evaluated as a function of particle size (ranging from 0.4 to 10 µm), distance from the source of ions (1, 2 and 3 m) and relative air humidity (RH 30 vs. 70 %). Aerosols were sampled with the EPI system “off” and “on.” Removal efficiency was significantly greater for all pathogens when the EPI line was the closest to the source of aerosols. There was a greater reduction for larger particles ranging between 3.3 and 9 µm, which varied by pathogen. Overall airborne pathogen reduction ranged between 0.5 and 1.9 logs. Viable pathogens were detected with the EPI system “on,” but there was a trend to reducing the quantity of viable PRRSV and IAV. There was not a significant effect on the pathogens removal efficiency based on the RH conditions tested. In summary, distance to the source of ions, type of pathogen and particle size influenced the removal efficiency of the EPI system. The reduction in infectious agents in the air by the EPI technology could potentially decrease the microbial exposure for pigs and people in confinement livestock facilities.Electronic supplementary materialThe online version of this article (doi:10.1007/s10453-015-9413-3) contains supplementary material, which is available to authorized users.

Immunogenicity and persistence from different 3-dose schedules of live and inactivated polio vaccines in Chinese infants

BackgroundOPV is the only poliovirus vaccine used in the China EPI system, although IPV is available in the private market. We compared immunigencity and persistence among different schedules of IPV and OPV. Methods536 Chinese infants were enrolled into 4 groups receiving different schedules administered at 2, 3, and 4 months of age: IPV–OPV–OPV, IPV–IPV–OPV, IPV–IPV–IPV, and OPV–OPV–OPV. The I–I–I group received an 18-month IPV booster dose. Blood samples were collected before the first dose, after the third dose, and at 18 months for all groups, and also after the booster dose for the I–I–I group. Polio neutralizing antibody titers were assessed, and seroprotection rates were calculated after primary immunization and at 18 months of age. ResultsBefore the first dose, GMTs of the 4 groups ranged from 2.96 to 6.89, and seroprotection rates ranged from 17.6% to 54.3%. After 3 doses, the GMT of the I–O–O and I–I–O groups ranged from 901.09 to 1,110.12, and the GMT of the I–I–I group range was 212.02 to 537.52, significantly lower than for the 2 sequential schedules (P<0.001). Seroprotection rates were 98.1% to 100%, with no significant differences among groups. At 18 months of age, the GMTs declined to a range of 527.00 to 683.44 in the I–O–O and I–I–O groups, and declined to 150.04 to 239.89 in the I–I–I group, significantly lower than for the other 3 groups (P<0.001). ConclusionsThe sequential schedules achieved high GMTs and seroprotection. The IPV-only schedule achieved high seroprotection but with lower GMTs. Sequential schedules are suitable for China. With the 2 sequential schedules, GMTs remained high at 18 months of age and were not inferior to the OPV-only schedule. Thus, with a sequential schedule, the booster dose could be given at 4 years of age, the same age as the current OPV booster dose.

Selective Epitaxial Si:P Film for nMOSFET Application: High Phosphorous Concentration and High Tensile Strain

Semiconductor industry is in the era of transition from 2D transistors to 3D transistors (for example, FinFETs). The scaling–down of transistor source/ drain (S/D) contact area causes more challenges in reducing the S/D parasitic resistance which becomes comparable to (or even higher than) the channel resistance itself. A highly phosphorous doped Si epitaxial film on S/D is crucial to reduce the parasitic resistance in nMOSFET transistors. Besides that, 2D/3D nMOSFET transistors favor the tensile strain induced in the channel to enhance the electron channel mobility. Here we present a selective Si:P epitaxial film growth which provides both high phosphorous concentrations (>1E+21 at/cc) and high tensile strain (comparable to ~1 at.% of Csub in Si:CP).This selective Si:P epitaxial process was performed using dichlorosilane (DCS), phosphine (PH3), and hydrochloride (HCl) gases in Applied Materials Centura RP Epi system. Grown highly concentrated, highly tensile-strained Si:P (called HS Si:P) films were analyzed by techniques of high-resolution XRD (HR-XRD), four-point Rs probe, SEM, TEM, and SIMS, etc.Table 1 compares two types of Si:P epitaxial films: conventional Si:P Epi versus HS Si:P Epi. In Fig. 1(a), the total [P] by SIMS in HS Si:P epitaxial film is 1.75E+21 at/cc (~ 3 at.% in silicon), about one magnitude order higher than in conventional Si:P film, much higher than the solid solubility (~3E+20 at/cc) of phosphorous in silicon at 700°C [1]. The 0.6 mΩ-cm resistivity in HS Si:P epitaxial film indicates that only ~1.3E+20 at/cc phosphorous atoms are electrically active. In Fig. 1(b), the HR-XRD profile from HS Si:P film shows a strong tensile strain equivalent to ~0.8 at.% Csub from a Si:CP film. We assume that majority of phosphorous atoms are covalently bonded with adjacent Si atoms in a stable Si-P compound phase –pseudocubic Si3P4 which is energetically favored relative to other Si3P4 phases [2]. With the Vegard’s law (of linear relationship between lattice parameter and alloy concentration) applied between Si and pseudocubic Si3P4 (which has a smaller lattice constant than Si), the tensile strain induced in HS Si:P film matches well the HR-XRD data, as previously reported by Z. Ye et. al.[3].Fig. 2 plots out selective HS Si:P epitaxial process sensitivity to growth temperature (675-775°C) regarding resistivity, strain, and total [P]. HS Si:P epitaxial films are stable without obvious phosphorous out-diffusion in this temperature range, which is confirmed by SIMS measurements. Both total [P] level and tensile strain decrease with the increasing temperature. Meanwhile, resistivity drops from 0.7 mΩ-cm @675°C to 0.5 mΩ-cm @725°C as more phosphorous atoms are electrically activated at higher temperature.Fig. 3 characterizes the HS Si:P film epitaxial growth on the (110) orientated substrate. The HR-XRD profile in Fig. 3(a) indicates a well-ordered HS Si:P epitaxial film grown on the (110) substrate. The TEM image in Fig. 3(b) shows a HS Si:P epitaxial film grown on (110) substrate without defects at interface, which is very significant for epitaxial growth around non-planar structures. Furthermore, Fig. 4(a) and (b) present two high-quality HS Si:P films with few defects, epitaxially grown on a planar structure and a Si fin structure, respectively.HS Si:P epitaxial films have been studied after the millisecond annealing treatment @900-1300°C in Fig. 5. After annealing, resistivity drops from 0.65 mΩ-cm @1050°Cto ~ 0.3 mΩ-cm @1150°C and above. Tensile strain in film is stable up to 1200°C. At 1250°C and above, HS Si:P epitaxial film obviously starts to partially lose the strain likely because some phosphorous atoms are released from the structure of pseudocubic Si3P4 at such high temperatures.Overall, this selective HS Si:P epitaxial process demonstrates its great potential in 2D/3D nMOSFET application.

The Strategy to Further Control and Elimination Measles in China Based on the Analysis of 10 Years Measles Suspects Accumulation in Guangxi

Objective: Trying to find the strategy to further control and elimination measles in China. Method: Calculated the measles suspects accumulated in Guangxi from 1995-2004 based on estimate coverage with the provincial birth rate and the reported registered newborn in the EPI system, and the antibody positive rate of measles vaccine in 1999, while analyzing the measles rebounds interval years and its reasons in Guangxi, forming the further control and elimination strategy recommendation for the whole China. Results: Measles rebounds with the interval of 3 years in Guangxi for the 230,000 newborn as suspects every year since the coverage and the antibody positive rate is not high enough of the routine vaccination, and the accumulation of the suspects of 3 years met the newborn cohort of 700,000 a year meanwhile causing the measles bound up in Guangxi. It also can also explain why the measles rebound in 1997, 2001 and 2005 in China, typically with the interval of very 3 years. Conclusion: In order to get the elimination of measles down in China in 2012, the strategies have to be taken including strengthening the routine immunization similarly in Guangxi with the poor performance warning mechanism; identifying the high risk area of outbreak or poor coverage to take mass campaign before the outbreak happen, and making sensitive surveillance from the provincial to township hospital to find out the beginning outbreak and contain it timely.

Efficiency of immunization service in the Gambia: Results of a stakeholder analysis

The literature demonstrates that conducting a stakeholder analysis to better understand the immunisation context and to involve the stakeholders in the assessment improves the quality and relevance of the assessment and increases the use of results by policy makers thereby ensuring that the programme provides efficient services. This stakeholder analysis is part of a study to assess the sustainability of the expansion of the expanded programme of immunisation in The Gambia. This paper reports and discusses the results of the study on the dimension of attaining high levels of technical efficiency of immunization programmes. Methods: The study, was conducted on the Immunisation service of the Gambia in West Africa. The method used was a series of in-dept interviews with sixteen key stakeholders at the central, divisional and facility levels. A stakeholder analysis tool that incorporates key indicators of financial sustainability of the EPI was used in the interviews. Results show that overall the majority of stakeholders strongly support the use of additional resources for implementing several actions (indicators) that can foster the financial sustainability of the EPI, including those that fall under the dimension of efficient immunisation services. Results further demonstrate that wastage is a very serious problem in the immunization system, which stakeholders generally felt is unacceptable. The causes could be grouped into four groups of factors: staff factors, resource factors, client factors and management/policy factors. Inefficiencies in the immunisation system, leading to, amomg other things, wastage of resources make expenditures in the EPI system unsustainable for a country that is experiencing slow economic growth and decreasing donor support. More intensified efforts to minimise the inefficiencies are needed to bring about more significant changes for the better

Loading Effects in the Selective Epitaxial Growth of n-Type Doped SiGe-Structures with LPCVD

In the last years, there was growing interest in the selective growth of strained SiGe-structures with n-type doping for source/drain engineering in NMOS. Phosphine (PH3) and arsine (AsH3) were under investigation as dopants (1,2). Howewer, data on homogeneity over the patterned wafer due to the mask layout (loading effects) are still lacking. We investigate selective epi with a dichlorosilane(DCS)-germane(GeH4)-PH3/AsH3- chemistry. The layers were deposited in an Applied Materials Centura Epi system and the characterization was done by SIMS, SEM, Spectral Ellipsometry, mechanical stylus profiling and 4-pt- probing.

Prediction of jet flows in the supersonic nozzle and diffuser

AbstractThe authors' recently‐developed code for a needle‐free powdered vaccine delivery device, the epidermal powdered inject system (EPI), is summarized in this paper. The behaviour of supersonic jet flows, which accelerate micron sized powdered vaccines to penetrate human skin or mucosal tissue, is therefore of great importance. A well‐established modified implicit flux vector splitting (MIFVS) solver for the Navier–Stokes equations is extended to study numerically the transient supersonic jet flows of interest. A low Reynolds number k–ε turbulence model, with the compressibility effect considered, is integrated into MIFVS solver to predict the turbulent structures and interactions with inherent shock systems. The results for the NASA validation case NPARC, Venturi and contoured shock tube (CST) of the EPI system are discussed. Copyright © 2005 John Wiley &amp; Sons, Ltd.

Analysis of acoustic noise in MRI

Acoustic or sound noise due to gradient pulsing has been one of the problems in magnetic resonance imaging (MRI), both in patient scanning as well as in many areas of psychiatric and neuroscience research such as functional MRI. Our recent observations in functional MRI for the visual and motor cortex show very different results with sound noise in comparison with the results obtained without sound noise. Although a number of ideas have been suggested in the literature about the possible elimination or reduction of sound noise, progress has been slow due to the basic role of gradient pulsing in MR imaging. Before we tackle the sound-noise-reduction problem, we believe that a systematic study of sound or acoustic noise behavior will provide important information for future endeavors in this area of research in MRI systems, in both commercial and research systems. Therefore, we report on some typical behavior of sound noise observed from MRI scanners and the analyses of their characteristics. Data are obtained both from a commercial MRI scanner (GE Signa 1.5-T EPI system) as well as a research-type MRI scanner (KAIS 2.0-T) developed at a university laboratory setting.