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This paper presents the novel design and analysis of a 25 W broadband Class-AB GaN HEMT-based power amplifier working over 0.9–1.7 GHz. A large signal model of the Wolfspeed-make GaN HEMT CG2H40025 has been used in this design. The comprehensive design process has been carried out with the help of the Advanced Design System software by Keysight. Instead of conjugately matching the load and source impedance obtained from load-pull analysis of a nonlinear model of CG2H40025, the value of load and source impedance has been tuned with the help of a novel design approach of an ideal matching design approach. Thus, to achieve an output power of more than 25 W and a flat large signal gain of 15.425 ± 0.375 dB, a novel design approach has been employed to create input and output matching networks, maintaining a lower Q value results in broad bandwidth and for determining the load and source impedances. The circuit has been fabricated on Roger’s substrate RO4350B having a dielectric constant of 3.66 and a loss tangent of 0.0031. The unique design approach based on electromagnetic simulation of the circuit at each design step yielded experimental results that agreed very well with the simulated results. The fabricated power amplifier achieves a power-added efficiency of over 54.78% and a drain efficiency of over 55.45% throughout the entire frequency range. It also delivers a maximum output power of 32.18 W at 1.3 GHz. This power amplifier is developed for L-band Foliage Penetrating Radar.

This paper analyses the effect of introducing multi-cavity-backing up to four cavities on a two-layered suspended stacked one bottom four top rectangular microstrip antenna. The analysis brings out the concurrent enhancement of bandwidth, gain and isolation between two antennas with progressive cavity-backing up to three cavities. Compared to stacked rectangular microstrip antennas without cavity, the single and triple cavity-backed configurations yielded a 40% and 83% enhancement in bandwidth and 0.80 and 2.20 dB enhancement in gain, respectively. The proposed novel triple cavity-backed one bottom four top rectangular microstrip antenna yields a bandwidth of 65.2% and an average gain of 12.85 dBi with an efficiency of 89%. The triple cavity-backed configuration yielded cross-polarization of less than −50 dB in both E and H planes and two such proposed antennas with rim-to-rim separation of 0.35 λ0give uniform isolation better than 40 dB covering the entire bandwidth. Measured results are in close agreement with the simulated one, which validates the performance of the antenna. The proposed antenna is deemed suitable for Through the Wall and Ground Penetrating Radar applications because of the improved characteristics offered by the proposed antenna in the S-band.

A comprehensive analysis on performance of Dolph-Tschebyscheff distribution for different array length and side lobe levels has been presented in this paper. Dolph-Tschebyscheff array, which is a compromise between binomial and uniform array, produces optimum side lobe level, efficiency, and half power beamwidth, hence, it is referred to as optimum distribution. For a larger number of elements, the Tschebyscheff array demands higher side lobe suppression in order to avoid the abrupt amplitude distribution at the edges that results from more elements and lower side lobe suppression, at the same time, higher side lobe suppression decreases aperture efficiency and gain. These novel analyses have been carried out by computing parameters such as power pattern, first side lobe level, directivity and half power beamwidth. Plots for optimum SLL and critical SLL are derived for a range of array elements, which defines three regions assisting in selection of appropriate number of elements and desired major-to-minor lobe levels for linear/planar array antenna designs. Practical array analysis is proposed by approximating the amplitude of arrays’ end elements, whenever it becomes higher than their adjacent elements.

In this paper, a new planar printed quasi-Yagi antenna with compact size and wide bandwidth is presented for a multiple-input-multiple-output (MIMO) antenna system. Antenna element consists of a rectangular driven monopole, a strip director, and a coplanar ground shorted reflector. A planar rectangular monopole is used for the first time as a driven element instead of a dipole to avoid the implementation complexity of BALUN as it can be fed directly by an unbalanced coaxial feed. It has been shown that the antenna element has an impedance bandwidth (|S11| < −10 dB) of 60.5% ranging from 1.59 to 2.97 GHz. Based on this element, a four-element pattern diversity MIMO antenna is proposed. By utilizing the ground of one element as a reflector for the successive element, a compact size of 109 mm × 109 mm (0.54λ0 × 0.54λ0at 1.5 GHz) has been obtained. Measured bandwidth of 65.9% (1.5–2.97 GHz) with minimum isolation of 13 dB has been achieved. The measured directional patterns and an average gain of 4 dBi, remain stable in the operating band with cross-polarization levels less than −25 dB. The envelope correlation coefficient and channel capacity loss show good diversity performance.

The U.S. High-Luminosity LHC Accelerator Upgrade Project (HL-LHC AUP) has, in the recent years, developed assembly specifications for the 4.5 m long MQXFA magnets, which are 150 mm aperture high-field Nb3Sn low-β quadrupole magnets that are being built for the CERN Hi-Luminosity LHC (HL-LHC) upgrade. While the specifications were based on lessons learned from the LHC Accelerator Research Program (LARP) effort and the MQXFS and MQXFA prototype magnets, the experience gained from having both MQXFA07 and MQXFA08 magnets not meeting performance specifications during cold testing actually catalyzed a better understanding of the impact of the target assembly specifications and a subsequent refinement of the same. This paper summarizes a body of assembly data from the Pre-Series (MQXFA03-MQXFA07) and Series magnets (MQXFA08-MQXFA11) that have been built to date, and discusses the processes employed to successfully face the challenge of ensuring that the assembly specifications are met for the duration of the project.

Under the U.S. High Luminosity LHC Accelerator Upgrade Project (HL-LHC AUP), the 150 mm bore, high-field Nb3Sn low-β MQXFA quadrupole magnets are being fabricated, assembled and tested, in the context of the CERN Hi-Luminosity LHC (HL-LHC) upgrade. These magnets have 4.2 m magnetic length and 4.56 m long iron yoke. To date, eight MQXFA magnets have been tested. One of the magnets additionally underwent a successful endurance test with 40 triggered quenches, and two magnets did not perform as expected. This work summarizes for the first time the available strain gauge data from eight identical Nb3Sn MQXFA tested magnets, focusing on the endurance test, and on a possible cause of underperformance of the two magnets that did not pass the vertical test. We applied methods to prevent this from happening in future MQXFA magnets, which shown to be effective for last two tested magnets.

ABSTRACTModified design of triangular-shaped microstrip antenna is proposed for circular polarized response which yields an axial ratio bandwidth of 68 MHz (∼5%) in the L-band. Furthermore, its electromagnetically coupled stacked design is presented, which yields enhanced impedance and axial ratio bandwidth of more than 1100 (∼70%) and 90 MHz (>7%), respectively. A single and stacked antenna offers a broadside pattern with a peak gain of 9 dBi. As a part of the design procedure, resonant length formulation at patch modes is presented. This serves as a guideline in the re-designing of similar antenna in a given frequency spectrum. Theoretical results have been verified experimentally with a good agreement.

Background: Manometry is the gold standard diagnostic test for achalasia. However, there are incidences where manometry cannot be obtained preoperatively, or the results of manometry is inconsistent with the patient's symptomatology. We aim to determine if intraoperative use of EndoFLIP can provide a diagnosis of achalasia and provide objective information during Heller myotomy and Dor fundoplication. Methods: To determine the intraoperative diagnostic EndoFLIP values for patients with achalasia, we determined the optimal cut-off points of the distensibility index (DI) between patients with a diagnosis of achalasia and patients with a diagnosis of hiatal hernia. To evaluate the usefulness of EndoFLIP values during Heller myotomy and Dor fundoplication, we obtained a cohort of patients with EndoFLIP values obtained after Heller myotomy and after Dor fundoplication as well as Eckardt score before and after surgery. Results: Our analysis of 169 patients (133 hiatal hernia and 36 achalasia) showed that patients with DI &lt; 0.8 have a >99% probability of having achalasia, while DI > 2.3 have a >99% probability of having hiatal hernia. Patients with a DI 0.8–1.3 have a 95% probability of having achalasia, and patients with a DI of 1.4–2.2 have a 94% probability of having a hiatal hernia. There were 40 patients in the cohort to determine objective data during Heller myotomy and Dor fundoplication. The DI increased from a median of 0.7 to 3.2 after myotomy and decreased to 2.2 after Dor fundoplication (p&lt; 0.001). The median Eckardt score went down from a median of 4.5 to 0 (p&lt; 0.001). Conclusions: Our study shows that intraoperative use of EndoFLIP can facilitate the diagnosis of achalasia and is used as an adjunct to diagnose achalasia when symptoms are inconsistent. The routine use of EndoFLIP during Heller myotomy and Dor fundoplication provides objective data during the operation in a group of patients with excellent short-term outcomes.

A technique of loading shorting posts on the patch has been used to enhance the directivity of a circular microstrip antenna (CMSA) in this paper. The shorting posts connected between the patch and the ground plane, force the electric field to become zero at that point, thereby modifying various modes of the circular patch. The shorting posts, also perturb the surface current distribution on the patch that help to increase its electrical size, which – in turn – enhances directivity at fixed resonance frequency. Investigations on various radii and positions of the shorting posts – to enhance the directivity of a CMSA, have been carried out. A systematic analysis on the performance of the CMSA at a lower order mode, fundamental mode and higher order mode frequencies with the loading of shorting posts has also been presented. The simulated and measured results show that the directivity of CMSA can be enhanced by up to 2 dB using the proposed technique without changing the patch geometry. In addition, the proposed antenna configuration yields, a bandwidth enhancement of almost three times as compared to that of a conventional CMSA. The simulated results of the conventional and shorted CMSA are experimentally validated with good agreement.

Current methods for diagnosing human disease are still incapable of rapidly and accurately screening for multiple diseases simultaneously on a large scale, and at an affordable price. MALDI-ToF mass spectrometry is an ultra-sensitive, ultra-fast, lowcost, high-throughput technology that has the potential to achieve this goal, allowing human phenotype characterization and thus phenomic screening for multiple disease states. In this review, we will discuss the main advances achieved so far, putting forward targeted applications of MALDI-ToF mass spectrometry in the service of human disease detection. This review focuses on the methodological workflow as MALDI-ToF data processing for phenomic analysis, using state-of-the-art bioinformatic pipelines and software tools. The role of mathematical modelling, machine learning, and artificial intelligence algorithms for disease screening are considered. Moreover, we present some previously developed tools for disease diagnostics and screening based on MALDI-ToF analysis. We discuss the remaining challenges that are ahead when implementing MALDI-ToF into clinical laboratories. Differentiating a standard profile from a single disease phenotype is challenging, but the potential to simultaneously run multiple algorithm screens for different disease phenotypes may only be limited by computing power once this initial hurdle is overcome. The ability to explore the full potential of human clinical phenomics may be closer than imagined; this review gives an insight into the benefits this technology may reap for the future of clinical diagnostics.

Metal borides have attracted the attention of researchers due to their useful physical properties and unique ability to form high hydrogen-capacity metal borohydrides. We demonstrate improved hydrogen storage properties of a nanoscale Mg–B material made by surfactant ball milling MgB2in a mixture of heptane, oleic acid, and oleylamine. Transmission electron microscopy data show that Mg–B nanoplatelets are produced with sizes ranging from 5 to 50 nm, which agglomerate upon ethanol washing to produce an agglomerated nanoscale Mg–B material of micron-sized particles with some surfactant still remaining. X-ray diffraction measurements reveal a two-component material where 32% of the solid is a strained crystalline solid maintaining the hexagonal structure with the remainder being amorphous. Fourier transform infrared shows that the oleate binds in a “bridge-bonding” fashion preferentially to magnesium rather than boron, which is confirmed by density functional theory calculations. The Mg–B nanoscale material is deficient in boron relative to bulk MgB2with a Mg–B ratio of ∼1:0.75. The nanoscale MgB0.75material has a disrupted B–B ring network as indicated by X-ray absorption measurements. Hydrogenation experiments at 700 bar and 280 °C show that it partially hydrogenates at temperatures 100 °C below the threshold for bulk MgB2hydrogenation. In addition, upon heating to 200 °C, the H–H bond-breaking ability increases ∼10-fold according to hydrogen–deuterium exchange experiments due to desorption of oleate at the surface. This behavior would make the nanoscale Mg–B material useful as an additive where rapid H–H bond breaking is needed.

Background: We postulated that the use of robotics may improve outcomes in hiatal hernia repair. Methods: We performed a retrospective analysis of a prospectively collected Society of Thoracic Surgery database at a single institution of patients who underwent elective hiatal hernia repair from 2012 to 2017 using either laparoscopy or the da Vinci Xi robot. We compared patient characteristics and outcomes and then performed univariate and multivariate logistic regression modeling to determine the factors associated with postoperative morbidity. Results: There were 293 consecutive patients who underwent elective hiatal hernia repair using either a laparoscopic (n = 151) or a robotic (n = 142) technique. There were no significant differences in age, gender, BMI, smoking history, presence of comorbidity, or hiatal hernia type. Seventy percent of the cases were a repair of either type III or type IV hiatal hernia. There were significantly higher ASA III and IV (7.9% vs. 4.2%, P = 0.03), higher Toupet fundoplication (83.4% vs. 44.4%, P &lt; 0.001), and lower redo-repair (7.3% vs. 20.4%, P = 0.001) in the laparoscopic group compared to the robotic group. The hospital length of stay was significantly shorter (1.3 ± 1.8 vs. 1.8 ± 1.5 days, P = 0.003) and there were significantly lower rates of complications (6.3 vs. 19.2%, P = 0.001) after robotic compared to laparoscopic hiatal hernia repair. There was no difference in readmission rate and mortality. Multiple logistic regression analysis showed that older age and laparoscopic technique were associated with higher complications after surgery. Conclusion: The use of the Da Vinci Xi robot in our institution was associated with improved outcomes compared to laparoscopic hiatal hernia repair despite a higher incidence of re-operative cases in the robotic group. Thus, short-term outcomes of Da Vinci Xi robot-assisted hiatal hernia repair are not inferior to laparoscopic hiatal hernia repair. Further studies are needed to determine if Da Vinci Xi robot provides superior short-term and long-term outcome in treatment of symptomatic hiatal hernia.

ABSTRACTA design technique of an antenna array with amplitude distribution/tapering to suppress the first side lobe level by exploiting the property of the rectangular microstrip antenna (RMSA) is proposed. Non-identical antenna array elements have been designed using the RMSAs by varying their width and hence the gain (keeping the length and hence the frequency same) to obtain the amplitude distribution for a desired first side lobe level. This eliminates the need of a complicated feed network with unequal power division to realize amplitude tapering. The conceptualized design is verified for a number of corporate-fed arrays and an analysis is carried out to give design guidelines with respect to the number of elements in the array. A symmetric corporate-fed 8-element antenna array with a cosine-square over pedestal amplitude distribution, operating at 1.8 GHz, has been designed and fabricated to validate the proposed concept. There is a reasonable agreement between simulated and measured results.

The completion of the human genome project in 2003 represented a major scientific landmark, ushering in a new era with hopes and expectations of fresh insights into disease mechanisms and treatments. In inflammatory bowel disease (IBD), many important discoveries soon followed, notably the identification of >200 genetic susceptibility loci and characterization of the gut microbiome. As “big data”, driven by advances in technology, becomes increasingly available and affordable, individuals with IBD and clinicians alike yearn for tangible outcomes from the promise of “precision medicine”—precise diagnosis, monitoring, and treatment. Here, we provide a commentary on the prospects and challenges of precision medicine and biomarkers in IBD. We focus on the three key areas where precision IBD will have the most impact: (1) disease susceptibility, activity, and behavior; (2) prediction of drug response and adverse effects; and (3) identification of subphenotypic mechanisms to facilitate drug discovery and selection of new treatments in IBD.

OBJECTIVES:There is an unmet need for novel blood-based biomarkers that offer timely and accurate diagnostic and prognostic testing in inflammatory bowel diseases (IBD). We aimed to investigate the diagnostic and prognostic utility of serum calprotectin (SC) in IBD.METHODS:A total of 171 patients (n=96 IBD, n=75 non-IBD) were prospectively recruited. A multi-biomarker model was derived using multivariable logistic regression analysis. Cox proportional hazards model was derived to assess the contribution of each variable to disease outcomes.RESULTS:SC correlated strongly with current biomarkers, including fecal calprotectin (FC) (n=50, ρ=0.50, P=1.6 × 10−4). SC was the strongest individual predictor of IBD diagnosis (odds ratio (OR): 9.37 (95% confidence interval (CI): 2.82–34.68), P=4.00 × 10−4) compared with other markers (C-reactive protein (CRP): OR 8.52 (95% CI: 2.75–28.63), P=2.80 × 10−4); albumin: OR 6.12 (95% CI: 1.82–22.16), P=0.004). In a subset of 50 patients with paired SC and FC, the area under receiver operating characteristic discriminating IBD from controls was better for FC than for SC (0.99, (95% CI 0.87–1.00) and 0.87 (95% CI:0.78–0.97), respectively; P=0.01). At follow-up (median 342 days; interquartile range: 88–563), SC predicted treatment escalation and/or surgery in IBD (hazard ratio (HR) 2.7, 95% CI: 1.1–4.9), in particular Crohn’s disease (CD) (HR 4.2, 95% CI 1.2–15.3). A model incorporating SC and either CRP or albumin has a positive likelihood ratio of 24.14 for IBD. At 1 year, our prognostic model can predict treatment escalation in IBD in 65% of cases (95% CI: 43–79%) and 80% (95% CI: 31–94%) in CD if ≥2 blood marker criteria are met.CONCLUSIONS:A diagnostic and prognostic model that combines SC and other blood-based biomarkers accurately predicts the inflammatory burden in IBD and has the potential to predict disease and its outcomes. Our data warrant further detailed exploration and validation in large multicenter cohorts.

An important factor to enhance the efficiency and productivity of advanced manufacturing processes is to improve the wear resistance (WR) of tool steels. Cryotreatment in recent years has established itself as a relatively inexpensive additional step in conventional heat treatment schedule that can substantially improve the WR of tool steels. This report highlights the state of understanding of this emerging process with an emphasis on illustrating the underlying mechanisms responsible for the enhancement of WR of tool steels. Cryotreatment almost completely removes retained austenite and induces favourable precipitation of refined secondary carbides with improved distribution. These benefits, if harnessed suitably, are capable of providing significant improvement in both productivity and product quality leading to an efficient economy of manufacturing.

An important factor to enhance the efficiency and productivity of advanced manufacturing processes is to improve the wear resistance (WR) of tool steels. Cryotreatment in recent years has established itself as a relatively inexpensive additional step in conventional heat treatment schedule that can substantially improve the WR of tool steels. This report highlights the state of understanding of this emerging process with an emphasis on illustrating the underlying mechanisms responsible for the enhancement of WR of tool steels. Cryotreatment almost completely removes retained austenite and induces favourable precipitation of refined secondary carbides with improved distribution. These benefits, if harnessed suitably, are capable of providing significant improvement in both productivity and product quality leading to an efficient economy of manufacturing.

In this paper, a new algorithm along with its first order hardware architecture is proposed to build the pseudorandom non-recursive binary sequence using sequence folding technique to protect the confidential information and data integrity in cryptography applications. Unlike the existing techniques to build the pseudorandom recursive sequence. The novelty of this proposed algorithm along with first order architecture is to generate non-recursive nibble of thirty one (O) from the input seed of four () bits. In the sequence folding technique, an arbitrary linear recursive binary sequence is folded to a minimum state by an empirical approach to build the non-linear Boolean function and realized using algebraic normal form. In this proposed first order architecture, the constructed non-linear Boolean functions are utilized to engender the pseudorandom binary non-recursive sequence. The proposed first order architecture is implemented using Verilog HDL and further prototyped on commercially available FPGA device ‘Spartan 3E xc3s500e-4fg320’. The realization of proposed architecture in this FPGA device accomplishes an improved data throughput, and efficiency (i.e. throughput/area) is compared to existing techniques. The generated binary sequence from the experiment is further analyzed briefly for sequence size, number of stages, correlation and verified for randomness by using NIST statistical test suites.

ABSTRACTThe main feature of an antenna array is its ability to form and scan the shaped main beam by using the amplitude and phase inputs as the controlling parameters at element level. In this paper, a comprehensive analysis of various parameters of a uniformly spaced linear array with respect to a number of elements for different amplitude distribution/window functions has been presented. There is a general assumption that any given window function will realize the expected parameters of the array even for a small number of array elements. A systematic study has been done to bring out very clearly the minimum number of elements that is required to realize antenna performance for a particular amplitude distribution. Effect of number of elements to obtain the desired first side lobe level and efficiency is presented. Contributions have been made to discuss the effects on directivity, gain, and beamwidth of the linear array.

A simulation based decision support model was used in the redesign of an emergency department (ED) with close to 180,000 visits per year. In order to accommodate high patient volumes at a single site ED, improving patient throughput time is necessary to maintain operational efficiency and to provide high quality patient care. A throughput time goal of arrival to departure under 3 h for 80% of ED patients was selected as the redesign project objective. Using discrete event simulation modeling, target areas for improvement are identified including optimized process flow, resource allocation and operational policies. Simulation modeling allows ED leadership to make decisions on operational changes using quantitative information of the impact of what-if scenarios on key performance measures. Based on simulation data results, changes in ED processes were implemented that resulted in 81% of patients having a length of stay in the ED of less than 3 h; a 30% improvement in average patient length of stay.

The structure–property relations of ductile cast irons (DCIs) with varying Cu content and ~1 wt% Ni has been investigated with an emphasis on examining their fracture toughness property towards the development of suitable materials for large volume containers for transport of spent fuel. The detailed microstructural characteristics, hardness, tensile and fracture toughness properties of three DCIs were assessed in as-cast and annealed conditions. Fracture toughness values were determined using both ball indentation (KBI) and J-integral (KJIc) tests. The obtained results assist to infer that: (1) the amount of pearlite and nodule count increases with increased amount of Cu, (2) the hardness and strength values increase whereas fracture toughness values marginally decrease with increased Cu content, and (3) the magnitudes of KBIestimated using a proposed analysis are in good agreement with KJIcvalues for the as-cast materials.

Nine asymmetrically spanned reinforced concrete deep beams were designed and tested to unreinforced web crushing failure in this experimental study to establish the appropriate shear stress limit for beam design. The lower bound and mean shear design limits associated with the concrete strut crushing in the web of the beam are identified, based on the better correlated concrete compressive strength parameter rather than its square root. A unified shear stress limit model is proposed to anchor the maximum strut crushing limit and sectional shear stress in design codes via a generic shear enhancement factor. The proposed unified model exhibits modest conservatism compared to the Hong Kong Code of Practice for Structural Concrete 2013 and the Chinese Code for Design of Concrete Structures (GB 50010). Transfer beams, pile caps and corbels, which are typically accompanied by high shear demand, can be optimised in size to leverage construction material cost savings through the more relaxed shear stress limit proposed in this study, which is justified through experiments.

An investigation has been carried out to identify the trends in maximum, minimum and mean temperatures and temperature range over the Indian land mass during the winter (January, and February), pre-monsoon (March–May), southwest monsoon (June–September) and post-monsoon (October–December) seasons by using high resolution daily gridded data set prepared by India Meteorological Department for the period of 1969–2005. It has been observed that the maximum temperatures over the west coast of India show rising trend in winter, southwest monsoon and post-monsoon seasons but the maximum temperatures do not show any significant trend over the other parts of the country. Minimum temperatures show increasing trend over the North Indian states in all seasons and they show an increasing trend over the west coast of India in winter and southwest monsoon seasons. Mean temperature shows an increasing trend over the west coast of India during winter and southwest monsoon seasons. Decreasing trend is observed in the temperature range over North India in all seasons due to increasing trend in minimum temperature.

ABSTRACTPrinted rectangular monopole antennas (PRMAs) have been investigated for increasing bandwidth. PRMAs with single, dual and triple microstrip line feed have been studied to show the effect of feed network to enhance the impedance bandwidth. Systematic study has been carried out to show the effects of patch width variation along with its offset feed, which leads to wideband antenna characteristics. The increase in bandwidth in the case of off-centred feed PRMAs is from 1.7 GHz (1.4–3.1GHz) to 3.9 GHz (1.3–5.2 GHz); this is more than 2.2 times as compared to single-centre-feed PRMA. Experiments have been carried out to verify the simulation results, which are in good agreement.

Neurocognitive impairment is common in people with Sickle Cell Disease (SCD) and evidence is accumulating that sleep disturbances play a role. The interaction between cortisol and sleep in the general population is associated with cognition as well as general wellbeing but there are few data in SCD. We aimed to understand the relationship between cortisol and sleep in individuals with SCD and explored associations with cognition.

The effect of bainite content on the fatigue threshold characteristics of ferrite–bainite dual phase steels is reported. Five different ferrite–bainite dual phase microstructures are prepared through suitable heat treatment and are subjected to hardness, tensile and fatigue tests apart from microstructural characterisations. Fatigue threshold ?Kthvalues of the steels are estimated using an earlier reported non-conventional method and the data are analysed to study the role of bainite content on ?Kth. The ?Kthvalues first decrease and then increase with increasing bainite content in the investigated steels. The nature of variation of ?Kthwith bainite content has been explained using the characteristics of the constituent phases.

AbstractMicrostrip Reflectarrays (MRAs) are typically excited using the horn antenna. In this paper, a different microstrip antenna feed to excite MRA, which is having patches of variable size, is proposed. Three different configurations namely, 2 × 2, Ave elements arranged in two orthogonal axes, and 3 × 3 element MRAs have been investigated to prove the concept. These configurations were first simulated using IE3D software, followed by their experimental verifications.

AbstractThe broadband and dual-band rectangular microstrip antenna is realized by cutting pair of toothbrush-shaped or step slots along the non-radiating edges of the patch. The toothbrush-shaped slot is said to introduce TMd0mode in between the TM10and TM20modes of the rectangular patch and realizes broadband response. In step slot cut configuration, the slot introduces a mode near the TM10mode resonance frequency of the patch and realizes dual frequencies. In this paper, a detail analysis to study the effect of slots on the broadband and dual-band response in these rectangular microstrip antennas (RMSAs) is presented. It was observed that the slot does not introduce any mode but modifies the resonance frequency of higher order orthogonal mode and realizes broadband and dual-band response. The slot alters the direction of surface currents at higher order mode and gives similar radiation pattern characteristics over the broader bandwidth and at the dual frequencies. In broadband RMSA, a formulation of resonant length at modified TM02mode is proposed. The frequency calculated using the same closely agrees with the simulated result.

Human papillomavirus (HPV) is directly associated with the occurrence and development of cervical cancer. Targeting HPV infection has become the priority in treatment and prevention. Some treatment strategies have shown a limited therapeutic potential in suppressing and reversing the oncogenic effects of HPVs, but are compromised by the toxicity, immune suppression and the expense. Arsenic trioxide (As2O3) has shown therapeutic efficacy in the treatment of haematological and solid cancer and has been demonstrated to effectively induce apoptosis of HPV-infected cervical cancer cells in vitro. Here, we examined the effects and possible molecular pathway of As2O3-induced apoptosis in HPV-infected and noninfected cervical cancer cells.

A series of impact tensile tests of spot welded joints made on interstitial free steel sheets have been carried out using a fabricated fixture. Spot welded samples were made from as received as well as prestrained steel sheets with the aim of examining the effect of prestrain on the impact tensile toughness of spot welds. The impact tensile toughness values of spot welds were found to be higher than their corresponding quasi-static toughness determined using tensile shear specimens. While the quasi-static toughness of spot welds decreases with increasing prestrain, the impact tensile toughness exhibits an opposite trend with prestrain within the range of investigation. The observed results have been discussed with considerations of specimen configurations, test procedure, microstructure, substructure, hardness profiles along the welds and post-failure examinations.

Hepatic failure has been treated successfully with clinical extracorporeal perfusions of porcine livers. However, dog-to-pig and pig-to-baboon liver xenotransplant models have resulted in severe bleeding secondary to liver xenograft-induced thrombocytopenia. Kupffer cells (KC) are abundant phagocytic cells in the liver. KC express the CD11b/CD18 receptor, which has been implicated in chilled platelet binding and phagocytosis through interaction with platelet surface proteins and carbohydrates. We sought to identify the role of KC CD18 in liver xenograft-induced thrombocytopenia.

AbstractThe dual-band microstrip antennas (MSAs) are realized by placing the stub on the edges of the patch or by cutting a slot at an appropriate position inside the patch. The multiband MSAs are realized by using the combination of the slot and stub. In this paper, by cutting a rectangular slot on the radiating edge and half U-slot on the nonradiating edge of a rectangular MSA, a dual- and triple-band rectangular MSA are proposed. These slots are of nearly quarter wave in length and by changing their lengths, tuning of the frequencies is realized. Also, the multiport network models for these multiband MSAs are proposed, which helps in understanding the mode distributions at slot and patch frequencies. To realize the higher gain, the suspended configurations of these multiband antennas are also proposed. A good agreement is obtained between the simulated, multiport network model, and measured results.

Abstract: This paper aims to provide an account of some interesting features of damage in metallic sheets under monotonic and cyclic loading using the information and understanding developed through a series of experimental investigations conducted on interstitial free steels. The experiments primarily consisted of damage evaluation in un-notched and notched sheets vis-à-vis that in thick specimens under monotonic loading, and that on sheets by interrupted or continuous cyclic loading. Some salient observations indicate that: (i) void nucleation occurs in two different stages, originating from non-metallic inclusions and precipitates. The critical strain for void nucleation at precipitates (ɛc) is lower for sheet metals than that in thick specimens. (ii) ɛc is a function of notch length in sheets, and the function assists to estimate the strength of particle/matrix interface, (iii) under cyclic loading, steel sheets exhibit non propagating microcracks below the endurance limit. Above the endurance limit slip bands promote formation of larger fatigue cracks primarily at ferrite grain boundaries. A series of grain boundary cracks link up to form meso-cracks, one of which grows to cause final failure and (iv) the growth of the macro-crack initially occurs in opening mode followed by its propagation in mixed mode through striations, intergranular cracking and through thickness necking prior to failure.

In order to nondestructively characterize the material (microstructural and mechanical) properties of M250 grade (UNS K93120) maraging steel, a study was designed to understand the influence of complex microstructu rat changes (precipitation of two intermetallics and austenitic reversion) of this steel on the mechanical properties and on three nondestructive testing (NDT) parameters. The NDT parameters (positron lifetime, magnetic Barkhausen emission peak root mean square voltage and ultrasonic velocity) and mechanical properties (yield strength and impact toughness) were measured on solution annealed (1093 K for 1 h) samples aged for various durations (755 K for 0.25 to 100 h). In the present study, an attempt has been made to compare the sensitivity and ability of the three NDT parameters in characterizing the developed microstructures. The decrease in discontinuity density due to discontinuity annihilation during initial aging and the increase in discontinuity density due to intermetallic precipitation upon longer aging could be revealed by positron lifetime. The study further showed that the precipitation of intermetallics during initial aging can be revealed by the ultrasonic velocity, and the austenitic reversion obtained upon longer aging can be revealed by the magnetic Barkhausen emission. However, none of the selected NDT parameters is found suitable for unambiguous identification of the technological regime (that is, optimum material properties achieved upon aging for 3 to 10 h). This paper demonstrates the applicability of a combination of two NDT parameters for qualifying the aging treatment corresponding to the technological regime in maraging steel. [ABSTRACT FROM AUTHOR]

Epigenetic modifications influence gene expression pattern and provide a unique signature of a cell differentiation status. Without external stimuli or signalling events, this cell identity remains stable and unlikely to change over many cell divisions. The epigenetic signature of a particular cell fate therefore needs to be replicated faithfully in daughter cells; otherwise a cell lineage cannot be maintained. However, the mechanism of transmission of cellular memory from mother to daughter cells remains unclear. It has been suggested that the inheritance of an active or silent gene state involves different kinds of epigenetic mechanisms, e.g. DNA methylation, histone modifications, replacement of histone variants, Polycomb group (PcG) and Trithorax group (TrxG) proteins. Emerging evidence supports the role of histone variant H3.3 in maintaining an active gene status and in remodelling nucleosomal composition. Here we discuss some recent findings on the propagation of epigenetic memory and propose a model for the inheritance of an active gene state through the interaction of H3.3 with other epigenetic components.

Triangular and Sawtooth wave generation at RF frequency is one of the important tasks for the design of buncher circuit in particle accelerators to increase the bunching efficiency. On the basis of Fourier series method different non-sinusoidal signals like triangular, sawtooth etc. are generated with combination of harmonics of sinusoidal signal with different amplitude and phase. These multi harmonic non-sinusoidal waves can be generated using passive RF components like phase-shifter, hybrid-coupler, power combiner/divider etc. This paper deals with lumped element approach for design and implementation of line phase shifters, 3-dB hybrid coupler and power divider/combiner, which have been used for the generation of triangular and saw tooth wave forms at 25 MHz. The ABCD (transfer) matrix formulation is used for the analytical prediction of the performance of these components. Experiments have been carried out to validate the analytical results.

Lipogenic diets that are completely devoid of methionine and choline (MCD) induce hepatic steatosis. MCD feeding also provokes systemic weight loss, for unclear reasons. In this study, we found that MCD feeding causes profound hepatic suppression of the gene encoding stearoyl-coenzyme A desaturase-1 (SCD-1), an enzyme whose regulation has significant effects on metabolic rate. Within 7 days of MCD exposure, hepatic SCD-1 mRNA decreased to nearly undetectable levels. By day 21, SCD-1 protein was absent from hepatic microsomes and fatty acids showed a decrease in monounsaturated species. These changes in hepatic SCD-1 were accompanied by signs of hypermetabolism. Calorimetry revealed that MCD-fed mice consumed 37% more energy than control mice (P = 0.0003). MCD feeding also stimulated fatty acid oxidation, although fatty oxidation genes were not significantly upregulated. Interestingly, despite their increased metabolic rate, MCD-fed mice did not increase their food consumption, and as a result, they lost 26% of their body weight in 21 days. In summary, MCD feeding suppresses SCD-1 in the liver, which likely contributes to hypermetabolism and weight loss. MCD feeding also induces hepatic steatosis, by an independent mechanism. Viewed together, these two disparate consequences of MCD feeding (weight loss and hepatic steatosis) give the appearance of an unusual form of lipodystrophy.

Lipogenic diets that are completely devoid of methionine and choline (MCD) induce hepatic steatosis. MCD feeding also provokes systemic weight loss, for unclear reasons. In this study, we found that MCD feeding causes profound hepatic suppression of the gene encoding stearoyl-coenzyme A desaturase-1 (SCD-1), an enzyme whose regulation has significant effects on metabolic rate. Within 7 days of MCD exposure, hepatic SCD-1 mRNA decreased to nearly undetectable levels. By day 21, SCD-1 protein was absent from hepatic microsomes and fatty acids showed a decrease in monounsaturated species. These changes in hepatic SCD-1 were accompanied by signs of hypermetabolism. Calorimetry revealed that MCD-fed mice consumed 37% more energy than control mice (P= 0.0003). MCD feeding also stimulated fatty acid oxidation, although fatty oxidation genes were not significantly upregulated. Interestingly, despite their increased metabolic rate, MCD-fed mice did not increase their food consumption, and as a result, they lost 26% of their body weight in 21 days. In summary, MCD feeding suppresses SCD-1 in the liver, which likely contributes to hypermetabolism and weight loss. MCD feeding also induces hepatic steatosis, by an independent mechanism. Viewed together, these two disparate consequences of MCD feeding (weight loss and hepatic steatosis) give the appearance of an unusual form of lipodystrophy.

Renal transplant recipients have an increased risk of cardiovascular disease. Dyslipidaemia and obesity are complications of renal transplantation, in part a consequence of immunosuppressive agents. The link is established between elevated total and low-density lipoprotein cholesterol and risk of myocardial infarction following transplantation. In parallel with its increased prevalence in the general population, obesity has emerged as a major complication of transplantation. Recent evidence of the impact of dyslipidaemia and obesity on patient and graft survival is reviewed.

Different cell types have characteristic patterns of gene expression. Once a cell hasdifferentiated, its daughter cells nearly always differentiate in the same way. Themaintenance of cell lineage involves either instructions from a cell’s surroundings orthe inheritance of memory from a parent cell. In normal development, thedifferentiation state of a cell is remarkably stable and irreversible. However thetransplantation of a somatic cell nucleus to an enucleated egg often leads to acomplete reprogramming of gene expression. We summarize here the results of someAmphibian nuclear transfer experiments that reveal a memory of gene expression.This and some other experiments exemplify epigenetic memory that persists throughmany cell divisions. In the case of nuclear transfer experiments, the activelytranscribed state of a gene can be propagated through many cell divisions in theabsence of the stimulus that first induced the activity of this gene. We discuss thepossible basis of these two examples of persistent epigenetic memory, namelychanges at DNA methylation, and histone modifications.

The ectopic production of free hCGβ is a common phenomenon in epithelial tumours, a phenomenon originally believed to have no biological significance. However, it is now apparent that hCGβ may significantly effect tumour development by increasing cell populations through inhibition of apoptosis. The recently identified hCGββ homodimer, with topological similarities to cystine knot growth factors, has been suggested to be the responsible mediator of these novel tumourigenic responses. In this study we isolated hCGβ monomer from hCGββ homodimer using size exclusion chromatography and confirmed the separation by Western blotting. Using a tetrazolium bromide incorporation cell number quantification assay (MTT), we measured the growth effects of separated hCGβ fractions corresponding to monomeric (hCGβ) and dimeric (hCGββ) forms on the hCGβ responding cell line T24. Maximal increases in cell number corresponded to the elution peak of dimeric and monomeric hCGβ. In conclusion, it would appear that the recently observed hCGββ homodimer is no more bioactive than its monomeric counterpart, in stimulating bladder cancer cell growth. This strengthens the proposition that hCGβ may exert its antiapoptotic effects by antagonistic inhibition of other cystine knot growth factor receptors and not by a specific receptor-mediated homodimeric interaction as seen for its topological counterparts TGF, PDGF-B and NGF.

We have made significant improvements in the development of a fast, convenient fluorescence imaging technique for evaluating the acid generation efficiency of photoacids in chemically amplified photoresists. A pH sensitive fluorescent molecule, coumarin 6 (C6), is doped into a 193-nm commercial resist system for imaging. For the 193-nm resist systems studied here, the Ka of C6 lies within the range of acid concentrations that can be photogenerated, making it a suitable probe of the acid generation efficiency of various photoacid generators (PAGs). Resist formulations, each containing a candidate PAG, are doped with C6. The resist is spin coated onto wafers and patterned with 5-μm features, with each feature at a different exposure dose. Each wafer is then spectroscopically imaged with an epi-fluorescence microscope. The spectroscopic content of each feature in the dose ramp is determined and the resulting data are analyzed using a two-level optical titration model. The relative quantum yields of acid generation for several PAGs have been measured multiple times over the span of several months and are shown to be reproducible. Furthermore, we have compared the on-wafer fluorescence imaging technique with two nonindicator based (C-parameter and P-parameter) methods. Our results demonstrate an excellent agreement among the three techniques.

Abstract: The effects of prestrain on the ductile fracture behavior of two varieties of Cu-strengthened high-strength low-alloy (HSLA) steels have been investigated through stretch-zone geometry measurements. It is noted that the ductile fracture-initiation toughness of both the steels remained unaltered up to prestrains of ∼2 pct, beyond which the toughness decreased sharply. A methodology for estimating the stretch-zone dimensions is proposed. Fracture-toughness estimations through stretch-zone width (SZW) and stretch-zone depth (SZD) measurements revealed that the nature of the variation of ductile fracture toughness with prestrain can be better predicted through SZD rather than the SZW measurements. However, for the specimen geometries and prestrain levels that were investigated, none of these methods were found suitable for quantifying the initiation fracture toughness.

Correlation of acoustic emission (AE) total counts Nwith stress intensity factor Kand plastic zone size rphas been examined for data generated during tensile deformation of notched specimens of nuclear and commercial grade AISI type 304 stainless steel. The variation of total AE counts with stress intensity factor in log-log scale has indicated that Nis related to Kas N=AKmwhere Aand mare constants but the magnitudes of Aand mare different at low and high Kregimes. Both the steels indicate higher values of m up to macroyielding than those obtained from analysis of AE data between macroyielding and the stress corresponding to Kmaxvalues in the experiments. The magnitudes of m were found to be higher for the commercial grade steel than that for the nuclear grade one and dependent on thickness. Analysis of AE data has also indicated that the relationship between Nand rpcan be expressed by the equation N=arßp. The value of the constant ß was experimentally found to be 1.3 via microhardness measurements. This value is higher than the theoretically assumed value of ß~ 1in the literature. The value of m in the equation N=AKm can be obtained from the value of the exponent ß of the relationship N=arßas m=2ß and such values of mcan be correlated to the directly estimated values of the exponent in the N-Krelationship. The amounts of strain induced a‘ martensite formed at notch tips in the two steels were found to increase with increasing applied stress below the nominal yield strength of unnotched specimens.

Background & Aims:Bacterial wall products play an important role in the activation of immune and nonimmune cells of the intestinal mucosa. Toll-like receptors (TLRs) TLR2 and TLR4 have been identified as signaling receptors activated by bacterial wall components. Methods:Expression of TLRs in human intestinal mucosa obtained by endoscopy and surgery was analyzed by immunohistochemistry. Intestinal macrophages were isolated by immunomagnetic beads armed with a CD33 antibody. Reverse-transcription polymerase chain reaction was performed for TLR1–5. Results were confirmed by Northern blot and flow cytometry. Interleukin-1β messenger RNA (mRNA) was quantified by a polymerase chain reaction–enzyme-linked immunosorbent assay–kit. Results:Immunohistochemistry revealed a significant increase in the TLR2 and TLR4 antigen expression on submucosal cells in inflamed intestinal mucosa compared with non-inflamed mucosa. TLR expression was localized in intestinal macrophages by double-labeling techniques. No TLR–polymerase chain reaction product could be obtained with mRNA from CD33-positive macrophages from normal mucosa. We observed an induction of mRNA for TLR2, TLR4, and TLR5 in inflammation-associated macrophages. TLR1 and TLR3 were only detectable in blood monocytes. Monocytes reacted to lipopolysaccharide stimulation with a 3-fold and in vitro differentiated macrophages with a 16-fold increase of cellular interleukin-1β mRNA. Macrophages from normal mucosa did not respond to lipopolysaccharide showing the functional relevance of TLR expression. Conclusions:This study shows the inflammation-dependent induction of TLR2 and TLR4 expression in intestinal macrophages. The absence of TLRs abolishes the reactivity of mucosal macrophages to bacterial wall products. Presence of TLRs may thereby contribute to the inflammatory process.

This paper reports the incorporation of sulforhodamine B (SRB) in the octadecylamine Langmuir−Blodgett (LB) films and the adsorbability of the cationic LB films have been investigated. It was observed that the adsorption process mainly occurred due to the ionic interaction between the cationic amino group of the long-chain amine and the sulfonic group of the SRB dye. Surface pressure−area isotherm studies confirmed the strong interaction between the long-chain amine and the SRB dye and the change of orientation of the molecules were observed with variation of pH of the subphase. Absorption, steady-state and ultrafast time-resolved fluorescence spectroscopic studies suggested the presence of the monomer and dimer of the SRB molecule in the restricted geometry of LB films. Furthermore, the contents of the monomer and dimer depend on the concentration of the dye and the adsorption process. The orientation of the SRB dye molecule in the LB films determined by polarized absorption spectra indicated a lying-flat orientation of the SRB molecule. Structural characteristics of the LB films such as orientation, layer−layer distance, and topography of the film surface have been investigated by FTIR spectroscopy, low-angle X-ray diffraction, and atomic force microscopy (AFM). Our preliminary results imply that the functional molecules in LB films are incorporated with a desired orientation by means of designing the molecular structure of the adsorbates.

Abstract: A series of high-martensite dual-phase (HMDP) steels exhibiting a 0.3 to 0.8 volume fraction of martensite (V m ), produced by intermediate quenching (IQ) of a vanadium and boron-containing microalloyed steel, have been studied for toughness and fatigue behavior to supplement the contents of a recent report by the present authors on the unusual tensile behavior of these steels. The studies included assessment of the quasi-static and dynamic fracture toughness and fatigue-crack growth (FCG) behavior of the developed steels. The experimental results show that the quasi-static fracturetoughness (K ICV ) increases with increasing V m in the range between V m =0.3 and 0.6 and then decreases, whereas the dynamic fracture-toughness parameters (K ID , K D , and J ID ) exhibit a significant increase in their magnitudes for steels containing 0.45 to 0.60 V m before achieving a saturation plateau. Both the quasi-static and dynamic fracture-toughness values exhibit the best range of toughnesses for specimens containing approximately equal amounts of precipitate-free ferrite and martensite in a refined microstructural state. The magnitudes of the fatigue threshold in HMDP steels, for V m between 0.55 and 0.60, appear to be superior to those of structural steels of a similar strength level. The Paris-law exponents (m) for the developed HMDP steels increase with increasing V m , with an attendant decrease in the pre-exponential factor (C).

Abstract: The solid-particle erosion of metals and alloys at elevated temperatures is characterized by different mechanisms of material removal, depending on the temperature of exposure, impact velocity, impact angle, and flux rate of the eroding particles. The objective of this article is to delineate the prevalent erosion mechanisms in nickel and a nickel-20 chromium alloy over a large range of temperatures, impact velocities, impact angles, and particle feed rates. For this purpose, a specialized elevated-temperature erosion rig has been utilized. Nickel and a Ni-20Cr alloy have been chosen as the test materials, in view of their substantially different oxidation behaviors. Results from the present study indicate that while the erosion rate generally increases with increasing temperature, an increased particle feed rate causes a reduction in the erosion rate, especially at higher temperatures beyond 650 K. On the basis of a detailed examination of the morphology of the eroded surfaces and the subsurface features beneath the eroded surfaces, four different material removal mechanisms have been identified in the nickel, while only three material removal mechanisms were operative in the Ni-20Cr alloy. Utilizing the aforementioned information, erosion-oxidation (E-O) interaction mechanism maps (herein, termed E-O maps) delineating the regions of dominance of the various erosion mechanisms in an impact velocity-test temperature space have been constructed for Ni and a Ni-20Cr alloy. Finally, the differences in erosion behavior between the Ni and Ni-20Cr alloy have been identified and rationalized.