Standard Strip Research Articles

Design and fabrication of SOI micro-ring resonators based on sub-wavelength grating waveguides.

Standard silicon photonic strip waveguides offer a high intrinsic refractive index contrast; this permits strong light confinement, leading to compact bends, which in turn facilitates the fabrication of devices with small footprints. Sub-wavelength grating (SWG) based waveguides can allow the fabrication of low loss devices with specific, engineered optical properties. The combination of SWG waveguides with optical micro-resonators can offer the possibility of achieving resonators with properties different from the traditional SOI rings. One important property that SWG rings can offer is decreased light confinement in the waveguide core; this improves the resonator's sensitivity to changes in the cladding refractive index, making the rings ideal for refractive index sensing applications. In this paper, we present the design and experimental characterization of SWG based rings realized on SOI chips without upper cladding (permitting their use as sensors). The fabricated rings offer quality factors in the range of ~1k-6k, depending on SWG parameters. Based on the comparison of experimental and simulated data we expect sensitivities exceeding 383 nm/RIU in water and 270 nm/RIU in air, showing excellent potential for use in sensing applications.

Modeling Three Dimensional Effects on Cross Flow Instability from Leading Edge Dimples

The formation of shallow dimples near the leading edge of natural laminar flow wings can occur during operation due to impact by hail, potentially changing the stability characteristics and causing an early transition to turbulence downstream of the dimple. Changes in the base flow will be strongly three-dimensional in character putting this problem beyond the capability of the standard strip based approaches founded on conical flow assumptions that are routinely used in the aerospace industry. This paper describes the application of a fully 3d method to a dimple on a wing for flow resembling that on a natural laminar flow wing. Solving the three-dimensional compressible boundary layer equations for the base flow and using a point to point marching scheme for solving the 3d PSE equations, it is shown that high wave-number stationary cross-flow modes can become unstable and grow rapidly in the dimple wake in a region well beyond the leading edge where stationary cross-flow modes would normally be decaying.

A constant-force technique to measure corneal biomechanical changes after collagen cross-linking.

PurposeTo introduce a constant-force technique for the analysis of corneal biomechanical changes induced after collagen cross-linking (CXL) that is better adapted to the natural loading in the eye than previous methods.MethodsFor the biomechanical testing, a total of 50 freshly enucleated eyes were obtained and subdivided in groups of 5 eyes each. A Zwicki-Line Testing Machine was used to analyze the strain of 11 mm long and 5 mm wide porcine corneal strips, with and without CXL. Before material testing, the corneal tissues were pre-stressed with 0.02 N until force stabilization. Standard strip extensiometry was performed as control technique. For the constant-force technique, tissue elongation (Δ strain, %) was analyzed for 180 seconds while different constant forces (0.25 N, 0.5 N, 1 N, 5 N) were applied.ResultsUsing a constant force of 0.5 N, we observed a significant difference in Δstrain between 0.26±0.01% in controls and 0.12±0.03% in the CXL-treated group (p = 0.003) over baseline. Similarly, using a constant force of 1 N, Δstrain was 0.31±0.03% in controls and 0.19±0.02% after CXL treatment (p = 0.008). No significant differences were observed between CXL-treated groups and controls with 0.25 N or 5 N constant forces. Standard stress-strain extensiometry failed to show significant differences between CXL-treated groups and controls at all percentages of strains tested.ConclusionWe propose a constant-force technique to measure corneal biomechanics in a more physiologic way. When compared to standard stress-strain extensiometry, the constant-force technique provides less variability and thus reaches significant results with a lower sample number.

Standard addition strip for quantitative electrostatic spray ionization mass spectrometry analysis: Determination of caffeine in drinks.

Standard addition strips were prepared for the quantitative determination of caffeine in different beverages by electrostatic spray ionization mass spectrometry (ESTASI-MS). The gist of this approach is to dry spots of caffeine solutions with different concentrations on a polymer strip, then to deposit a drop of sample mixed with an internal standard, here theobromine on each spot and to measure the mass spectrometry signals of caffeine and theobromine by ESTASI-MS. This strip approach is very convenient and provides quantitative analyses as accurate as the classical standard addition method by MS or liquid chromatography.

The tarsal belt procedure for the correction of ectropion: description and outcome in 42 cases

Background/aimsEctropion correction is a challenge in plastic surgery. Correction of the lower lid area, including restoration of the shape and position of lid margin, is the surgical goal. In this...

Long-term results after radiofrequency ablation in 1998

Summary Introduction: In 1998, radiofrequency ablation (VNUS Closure Plus™) was authorised in Germany and Europe for the treatment of superficial reflux. We participated in a clinical registry set up by the manufacturing company in 1998. The aim of this retrospective paper was to analyse the long-term results after radiofrequency ablation. Materials, methods and patients: In 1998, we operated on twelve patients (8 women, 4 men). In accordance with the concept of standard vein stripping surgery, all endovenous ablations were combined with crossectomy or ligature of the saphenopopliteal junction. Each vein was thermally ablated over its entire length and no tumescent anaesthesia was performed. The mean age of the twelve patients was 44.9 years. On ten occasions, the entire length of the great saphenous vein was treated, on one occasion the great saphenous vein at the level of the lower leg and on one occasion the entire length of the small saphenous vein. The mean duration of surgery was 80 minutes. Results: The follow-up period was 3 to 168 months, with a mean duration of 80 months. Six patients were followed up for longer than 120 months. In eight cases, the follow-up examination was performed using duplex ultrasound, in two cases using clinical examination and non-invasive testing, in one case using clinical examination and in one case via a telephone interview.The most frequent perioperative complication, occurring in six cases, was hypaesthesia at the medial malleolus or lower leg. There was one case of perioperative thrombophlebitis of a lateral branch in the lower leg and one case of a third-degree thigh burn with subsequent infection of the great saphenous vein canal. No deep vein thrombosis or pulmonary embolism occurred in any of the operated patients.Of the eleven great saphenous veins treated, one recanalised after 14 months, the others had closed or were no longer detectable on ultrasound. The small saphenous vein treated was also no longer detectable.In one patient, a major recurrence at the saphenofemoral junction with recurrent lateral branches in the thigh and lower leg were determined 168 months after surgery. No recurrent varicosis was determined in the other patients.

Emergence of TEM, SHV, and CTX-M-Extended Spectrum β-Lactamases and Class 1 Integron AmongEnterobacter cloacaeIsolates Collected from Hospitals of Tehran and Qazvin, Iran

Extended-spectrum β-lactamase (ESBL) production is an important resistance mechanism among clinical isolates of Enterobacter cloacae. TEM, SHV, and CTX-M are the most common ESBL genotypes among Enterobacter spp. The main aims of this study were to determine the antimicrobial susceptibility pattern and to detect ESBL-encoding genes as well as intI1 genes. One hundred twenty isolates of E. cloacae were collected from hospitals of Tehran and Qazvin, Iran. The isolates were identified by standard laboratory methods and API 20E strips. ESBL screening was performed by the combined disk method. PCR and sequencing were conducted for detection of ESBL-encoding genes as well as intI1 genes. Clonal relatedness of ESBL-producing isolates was assessed by the enterobacterial repetitive intergenic consensus (ERIC)-PCR method. Of 120 isolates, 57 (47.5%) were characterized as multidrug resistant among those 48 (84.2%) isolates carried class 1 integron. Fifty-three (44.2%) isolates were found to be ESBL producers, in which bla(CTX-M-15) (60.4%) was the most common gene followed by bla(TEM-1) (32.1%), bla(TEM-169) (13.2%), and bla(SHV-12) (7.5%) either alone or in combination. Forty-four of the 53 (83.01%) ESBL-producing isolates were genetically unrelated. For the first time, this study describes the emergence of TEM-169, SHV-12, and CTX-M-15 ESBL genotypes in E. cloacae isolates in Iran.

A prospective study of venous hemodynamics and quality of live at least five years after varicose vein stripping

To assess venous hemodynamics and quality of life at lest five years after varicose vein stripping. We conducted a prospective study with 39 patients (63 limbs) with primary lower limbs varicose veins. Preoperatively, all patients were subjected to clinical evaluation, duplex ultrassound, air plethysmography (APG), and CIVIQ questionnaire of quality of life. By APG, venous filling index (VFI), ejection fraction (EF), and residual volume fraction (RVF) were determined. CIVIQ addresses four domains in course of 20 questions, including states of physical, social, and psychological well-being, and pain level. Varicose veins were treated by standard venous stripping. At least five years after surgery (77.9 ± 10.9 months), patients were reassessed and had clinical examination, duplex ultrasound, APG, and CIVIQ repeated. No late follow-up data was available for 24 patients. Preoperative and late postoperative VFI levels were similar, whereas EF (P=0.05) and RVF (P=0.01), as hemodynamic variables, significantly improved following surgery. In the late postoperative period, overall CIVIQ scores were significantly lower (P=0.005), as were scores in all four domains: pain (P=0.001), physical (P=0.007), social (P=0.008), and psychological (P= 0.05). In a small prospective cohort, improvements in venous hemodynamics and in quality of life of patients submitted to standard varicose veins stripping were maintained five years after the procedure.

Urogenital schistosomiasis and urological assessment of hematuria in preschool-aged children in rural communities of Nigeria

ObjectiveThe study evaluates the prevalence of urogenital schistosomiasis and diagnostic performance of chemical reagent strips used for disease diagnosis in preschool-aged children (≤5 years) in Nigeria rural communities. Patients and methodsUrine samples from 419 children were observed microscopically for Schistosoma haematobium and screened for hematuria using standard urine chemical reagent strips. ResultsPrevalence and intensity of infection were 9.8% and 14.4 eggs/10 ml of urine, respectively. Prevalence of infection was similar in girls (10%) and boys (9.6%) (p > 0.05). The intensity of infection was higher in boys (17.1 eggs/10 ml of urine) than in girls (12.8 eggs/10 ml of urine); however, this was not gender dependent (p > 0.05). The occurrence of hematuria was not associated with gender (p > 0.05), but was associated with prevalence of infection (p < 0.05). ConclusionInfection with S. haematobium occurs early in life in the communities and although intensity of infection is low, it could have serious implications in disease transmission. Hematuria, although moderately sensitive to infection, is an important morbidity indicator of urogenital schistosomiasis in the study population.

Complications of endovenous ablation in randomized controlled trials.

Endovenous ablation (EVA) of the great saphenous vein (GSV), with radiofrequency (RFA) or laser ablation (EVLA), has largely replaced the standard ligation and stripping (L&S). Several randomized controlled trials (RCTs) have reported data on efficacy of the ablation with little focus on complications. We analyzed the current literature for short-term complications of EVA as compared with L&S. We searched MEDLINE, the Cochrane Central Trials Registry, and individual journals from January 2008 through January 8, 2013 for RCTs comparing RFA and/or EVLA and/or L&S to treat GSV incompetence. We excluded studies using foam sclerotherapy, re-do GSV surgery, or the addition of a high GSV ligation to an EVA procedure. We meta-analysized short-term (<1 year) complications using the Peto odds ratio to elucidate differences between RFA (using the VNUS ClosureFAST catheter; VNUS Medical Technologies, Inc, San Jose, Calif), EVLA, and L&S. Seventeen RCTs met inclusion criteria. There were 317 patients who underwent RFA with ClosureFAST, 1057 patients who had EVLA, and 975 who had L&S. Seventy percent were female with a mean age of 47.5 years. The majority had CEAP clinical class 2 or 3. There was an overall complication rate of 39.6% in the 2624 limbs analyzed over all procedures. There was no evidence of a difference in the rates of venous thromboembolism. There was a significantly higher rate of wound infection for L&S (2.3%; 95% confidence interval [CI], 1.3%-3.1%) vs EVLA (0.5%; 95% CI, 0.3%-1.3%; P=.006), but not between L&S and RFA (1.5%; 95% CI, 0.4%-3.0%; P= .094). The paresthesia rate was significantly lower with EVLA (3.8%; 95% CI, 2.4%-4.5%) as compared with RFA (5.2%; 95% CI, 3.1%-7.9%; P< .001) and L&S (7.4%; 95% CI, 5.3%-8.3%; P< .001). The rate of thrombophlebitis was significantly lower for L&S (3.0%; 95% CI, 2.9%-4.0%) as compared with RFA (5.5%; 95% CI, 3.0%-7.8%; P= .003) and EVLA (5.6%; 95% CI, 4.2%-7.0%; P= .003). There was no difference in the rate of thermal skin burns between RFA and EVLA. Endovenous ablation and ligation and stripping of the GSV are not without complications, although usually minor. L&S has a higher wound infection rate and a lower thrombophlebitis rate as compared with EVA. EVLA has a significantly lower rate of paresthesia as compared with RFAand L&S. Thermal skin burns occur with equal frequency in RFA and EVLA.

Relationship between odontogenic bacteremia and orthodontic stripping

The aim of this study was to evaluate the prevalence of bacteremia associated with an orthodontic stripping procedure. The study included 29 orthodontic patients (mean age, 18.2 ± 3.4 years). We used a standardized stripping procedure: a perforated stripping disk with a contra-angle hand piece was used at a low speed (<15,000 rpm; 10 seconds) on the mandibular anterior teeth. Blood samples were collected by inserting a cannula into the left antecubital fossa. A baseline sample was taken before treatment, and a second sample was taken after the stripping procedure. These samples were inoculated into aerobic and anaerobic blood culture bottles and incubated, and the bacterial cultures were identified; the samples collected before and after the stripping procedure were statistically analyzed. Transient bacteremia was not detected in any pretreatment blood sample, but it was found in 1 postoperative blood sample; this sample tested positive for Streptococcussanguis. The bacterial species in the positive postoperative blood sample was S sanguis, which might be associated with infective endocarditis. Clinicians should explain the level of risk to the patient and consult a concerned medical specialist.

A charge collection study with dedicated RD50 charge multiplication sensors

This study investigates the charge collection efficiency of silicon strip detectors, produced by MICRON Semiconductor Co., Ltd. within the CERN RD50 collaboration, designed specifically to understand the effect of design parameters on the onset and magnitude of charge multiplication. Charge collection measurements are performed before and after irradiation with a proton fluence of 1×1015 1MeVneq/cm2 (neq/cm2) and neutron fluence ranging from 1–5×1015neq/cm2. Structures on these devices include varying diffusion times and energies for the implantation process, different sensor thicknesses, the use of intermediate biased or floating strips between the readout strips, and several different strip width and pitch geometries. The charge collection for these devices is studied as a function of the bias voltage, looking for indications of charge multiplication. Results are compared to standard float zone 300μm thick silicon strip sensors having a strip width of 25μm and pitch of 80μm.

Plasma morphology and induced airflow characterization of a DBD actuator with serrated electrode

Plasma morphology and airflow induced by a dielectric barrier discharge (DBD) actuator, whose exposed electrode geometry is designed with a serrated configuration, are investigated in quiescent air and compared with a DBD actuator consisting of electrodes designed with a standard linear strip configuration. ICCD imaging, electrical measurements and three-component laser Doppler velocimetry were carried out to compare various features of these two actuators. With the serrated configuration, ICCD images of the discharge show that streamers are bent, whereas with the linear configuration they are straight. These curved streamers induce a three-dimensional flow topology, which is confirmed by friction line visualization and velocity measurements. Whereas a two-dimensional wall-jet is induced with the linear configuration, a transverse velocity component is measured with the serrated configuration, implying the creation of spanwise-periodic vorticity. Phase-averaged velocity measurements allow the temporal variation of this transverse velocity to be highlighted. On both sides of a tooth, it has qualitatively the same variation as the longitudinal velocity with respect to the negative or positive half-cycles of the high voltage signal. Moreover, with the same electrical operating parameters, the measured longitudinal velocity was higher, particularly at the tips.

Comparative volumetric and clinical evaluation of peri-implant sulcular fluid and gingival crevicular fluid

PurposePeri-implant sulcular fluid (PISF) has a production mechanism similar to gingival crevicular fluid (GCF). However, limited research has been performed comparing their behavior in response to inflammation. Hence, the aim of the present study was to comparatively evaluate PISF and GCF volume with varying degrees of clinical inflammatory parameters.MethodsScreening of patients was conducted. Based on the perimucosal inflammatory status, 39 loaded implant sites were selected from 24 patients, with equal numbers of sites in healthy, peri-implant mucositis, and peri-implantitis subgroups. GCF collection was done from age- and sex-matched dentate patients, selected with gingival inflammatory status corresponding to the implant sites. Assessment of the inflammatory status for dental/implant sites was performed using probing depth (PD), plaque index/modified plaque index (PI/mPI), gingival index/simplified gingival index (GI/sGI), and modified sulcular bleeding index (BI). Sample collection was done using standardized absorbent paper strips with volumetric evaluation performed via an electronic volume quantification device.ResultsPositive correlation of the PISF and GCF volume was seen with increasing PD and clinical inflammatory parameters. A higher correlation of GCF with PD (0.843) was found when compared to PISF (0.771). PISF expressed a higher covariation with increasing grades of sGI (0.885), BI (0.841), and mPI (0.734), while GCF established a moderately positive correlation with GI (0.694), BI (0.696), and PI (0.729).ConclusionsWithin the limitations of this study, except for minor fluctuations, GCF and PISF volumes demonstrated a similar nature and volumetric pattern through increasing grades of inflammation, with PISF showing better correlation with the clinical parameters.

Effect of microstructure and composition on hydrogen permeation in X70 pipeline steels

The influence of microstructure and composition on permeation of hydrogen in 1.2 and 0.5 wt.% Mn X70 pipeline steels after different processing was investigated using an electrochemical permeation technique.For 1.2 wt.% Mn (standard Mn) steel, the microstructure of normalised transfer bar was coarse equiaxed ferrite grains. This sample exhibited the highest diffusivity, followed by transfer bar, with a mixed ferrite–bainitic ferrite microstructure; and hot rolled strip, with fine elongated ferrite grains.The 0.5 wt.% Mn (medium Mn) strip displayed lower diffusivity than the 1.2 wt.% Mn strip, due to hydrogen trapping by finer ferrite grains and a higher density of carbonitride precipitates. Moreover, the medium Mn strip exhibited a uniform microstructure and consequently similar diffusion coefficients for the edge and centreline regions, whereas the finer grains of the edge region of the standard Mn strip resulted in a lower diffusivity than the centreline region.

Ultra-thin silicon-on-insulator strip waveguides and mode couplers

We demonstrate an ultra-thin silicon waveguide for wavelengths around 1.55 μm, and mode converters designed for transitions to and from standard 500 nm × 220 nm strip waveguides. The devices were fabricated in a CMOS-compatible process requiring two photolithography and etch steps. The ultra-thin waveguides exhibited losses of 2.01 ± 0.231 dB/cm, exhibited bend radii as small as 30 μm with losses of 0.05 ± 0.005 dB per bend, and exhibited coupling losses of 0.66 ± 0.014 dB to standard strip waveguides.

Numerical Research on Flow Field Characteristics within the Slipstream of a Propeller

Numerical research on three dimensional flow field of a propeller and actuator disk model have been made. Under design conditions (headway 66.889m/s, revolving velocity 2575rpm）, the Slipstream flow field after Propeller is solved by RANS equations with structure mesh. Chosen 12 million mesh through verification of reliability analysis. The numerical result consists of the flow field and vortex field in the propeller slipstream. With comparison to the calculation result of standard strip theory and actuator disk model, it is shown that for light load propeller with the side small contraction of slipstream, in the slipstream cross section after 0.6R away from downstream of propeller rotation plane, the axial, circular and radial induced velocity coefficient by Prandtl’s blade tip corrected standard strip theory result; three dimensional flows numerical simulation and actuator disk model are well consistent. It verified the correctness of standard strip theory and also provided scientific basis for the correction of actuator disk model

On the complexity of planning for agent teams and its implications for single agent planning

If the complexity of planning for a single agent is described by some function f of the input, how much more difficult is it to plan for a team of n cooperating agents? If these agents are completely independent, we can simply solve n single agent problems, scaling linearly with the number of agents. But if all the agents interact tightly, we really need to solve a single problem that is n times larger, which could be exponentially (in n) harder to solve. Is a more general characterization possible? To formulate this question precisely, we minimally extend the standard STRIPS model to describe multi-agent planning problems. Then, we identify two problem parameters that help us answer our question. The first parameter is independent of the precise task the multi-agent system should plan for, and it captures the structure of the possible direct interactions between the agents via the tree-width of a graph induced by the team. The second parameter is task-dependent, and it captures the minimal number of interactions by the “most interacting” agent in the team that is needed to solve the problem. We show that multi-agent planning problems can be solved in time exponential only in these parameters. Thus, when these parameters are bounded, the complexity scales only polynomially in the size of the agent team. These results also have direct implications for the single-agent case: by casting single-agent planning tasks as multi-agent planning tasks, we can devise novel methods for decomposition-based planning for single agents. We analyze one such method, and use the techniques developed to provide some of the strongest tractability results for classical single-agent planning to date.

Use of lissamine green before conjunctival impression cytology and flow cytometry in patients with sjögren’s syndrome

AbstractPurpose Lissamine Green (LG) is a vital dye that stains damaged epithelial cells in ocular surface disease. Conjunctival Impression Cytology (CIC) is used with flow cytometry, to examine surface epithelial cells. We were concerned that, if used prior to CIC, cell uptake of LG might affect the fluorescent signal during flow cytometry. We therefore studied whether the use of LG before CIC, could cause fluorescence interference.Methods CIC was performed with two autoclaved Supor semicircular filters applied to the lateral bulbar conjunctiva of 6 patients with Sjögren's Syndrome. LG was eluted from a standard strip with a drop of anaesthetic and delivered into the inferior fornix. Two further filters were applied to the medial bulbar conjunctiva. Cells were recovered by agitation for 1 minute, washed, stained and analysed by flow cytometry.Results When compared with samples taken before LG instillation, cells isolated from all 6 samples taken after LG instillation, and excited at 630nm, showed an increase in fluorescence at 665nm. Some increased fluorescence was also noted at 680nm but was within the limits of spectral compensation. There was no observable effect of LG when cells were excited at 488nm.Conclusion Cell uptake of LG is detected by flow cytometry, predominantly in the 665nm channel when excited at 630nm. This persists despite cell washing. Whilst this excludes the use of fluorochromes that emit within this spectrum, the use of fluorochromes excited or emitting at other wavelengths, is feasible after LG staining.

DETERMINATION OF REFERENCE VALUES FOR INTRAOCULAR PRESSURE AND SCHIRMER TEAR TEST IN CLINICALLY NORMAL OSTRICHES (STRUTHIO CAMELUS)

The purpose of this study was to establish normal physiologic reference values for intraocular pressure (IOP) and Schirmer tear test (STT) results in clinically normal ostriches (Struthio camelus). Twenty ostriches of both sexes, 10 juveniles (1.5-2 yr of age) and 10 adults, were included in this study. Complete ophthalmic examination was performed prior to this investigation. STT was performed by inserting a standard sterile STT strip over the ventral lid margin into the ventral conjunctival sac for 60 sec. Following the STT, IOP was measured using applanation tonometry with the Tono-Pen Vet tonometer after topical instillation of one drop of 0.5% proparacaine ophthalmic solution. The mean +/- SD and range of Tono-Pen readings of IOP for all birds was 18.8 +/- 3.5, with a range of 12-24. Mean IOP in juvenile ostriches was 19.7 +/- 3.6. Mean IOP in adult ostriches was 16.9 +/- 2.9. There was no statistically significant difference between young and adult birds (P = 0.07). The mean STT values in the present study were 16.3 +/- 2.5 mm/1 min when measurements from both eyes were averaged. Mean STT in juvenile and adult ostriches was 15.4 +/- 1.8 and 17.2 +/- 2.9 mm/1 min, respectively. There was no statistically significant difference between young and adult birds (P = 0.11). No statistically significant differences between genders were found for any of the results (P > or = 0.41). In conclusion, this study provides normal reference range values for STT and IOP in clinically healthy ostriches.