gebhart/patrepeval huggingface dataset:
BRH test pattern for the evaluation of gamma-camera performance. (1981)

A transmission test pattern has been developed for the simultaneous evaluation of intrinsic resolution, field uniformity, and spatial distortion of gamma cameras of any model and age. Holes 2.5 mm in diameter are drilled with high precision through a 3.2-mm thick lead-alloy plate, forming an orthogonal array of holes. The minimal lead spacing separating adjacent holes is a constant 2.5 mm in th Y direction, but varies along the X axis, in groups of six holes, from 1.5-7 mm in steps of 0.5 mm. The performance of gamma cameras has been investigated with the gamma rays of Tc-99m and the low-energy photons from Xe-133 and Tl-201. Images of the test pattern provide a simple, rapid, and sensitive method for gamma camera quality control, acceptance testing of new instruments, and checking of a camera's operating and maintenance procedures.
Multi-channel algorithm for segmentation of tumor blood vessels using multiplexed image data (2016)

Angiogenesis is the development of new vasculature from existing vasculature. The developmental biology and pathology of angiogenesis are major focuses of biomedical research. While many segmentation algorithms have been implemented for blood vessel analysis, they are limited by maturation dependent variation in blood vessel protein expression, expression by other cell types and discontinuous vessel staining due to tissue sectioning. We describe a method that combines image data from multiple blood vessel-expressed proteins to dynamically estimate optimal correlation metrics to drive improved vessel segmentation. A single marker approach resulted in overestimation of vessel number, whereas the multi-channel algorithm agreed closely with manual counts generated by two independent observers. Our results suggest that this new approach improves the vessel segmentation, which will be useful in the study of angiogenesis in health and disease.
Multi-Bit Mixers for Digital-RF Receivers (2010)

HYPRES, Inc has successfully completed the development of the first-generation superconductor digital channelizing receiver. This channelizer circuit, comprising a single-bit digital in-phase and quadrature (I&Q) mixer and two second-order digital decimation filters (DDFs), was built with rapid single flux quantum (RSFQ) logic. The further development of digital-RF receivers requires a multi-bit (n × k) multiplier for digital mixing of n-bit data streams provided by advanced low pass or band pass modulator and k-bit digital local oscillator (LO). We report our results on the design of both n × 1-bit and 1 × k-bit mixers where either data or LO streams can have a multi-bit representation. The reported approach is the generalization of a 1 × 1-bit mixer used in the first-generation channelizer. The detailed block-diagrams are given for both types and the correct operation at low frequency of test chips with 3-bit mixers are reported. Design issues pertaining to scaling to a digital-RF receiver containing multi-bit mixers are discussed.
Formability of Twin-Roll Cast Age-Hardenable Mg-Zn Alloys (2009)

The suitability of a twin-roll cast (TRC) age-hardenable alloy for wrought applications is explored. A Mg-4Zn (wt.%) alloy, 3mm thick, was cast using the TRC route. Deviating from the traditional practice of homogenization followed by age-hardening in die/sand cast parts, the TRC sheet, cut into small strips, was hot rolled and annealed after homogenization. They were then deep drawn and subsequently age-hardened. The rollability, mechanical properties and microstructure of the alloy at different stages of processing and after forming, are presented and discussed.
Comparative study of α-helical and β-sheet self-assembled peptide nanofiber vaccine platforms: influence of integrated T-cell epitopes (2020)

Several different self-assembling peptide systems that form nanofibers have been investigated as vaccine platforms, but design principles for adjusting the character of the immune responses they raise have yet to be well articulated. Here we compared the immune responses raised by two structurally dissimilar peptide nanofibers, one a β-sheet fibrillar system (Q11), and one an α-helical nanofiber system (Coil29), hypothesizing that integrated T-cell epitopes within the latter would promote T follicular helper (Tfh) cell engagement and lead to improved antibody titers and quality. Despite significantly different internal structures, nanofibers of the two peptides exhibited surprisingly similar nanoscale morphologies, and both were capable of raising strong antibody responses to conjugated peptide epitopes in mice without adjuvant. Both were minimally inflammatory, but as hypothesized Coil29 nanofibers elicited antibody responses with higher titers and avidities against a conjugated model epitope (OVA<sub>323-339</sub>) and a candidate peptide epitope for vaccination against S. aureus. Subsequent investigation indicated that Coil29 nanofibers possessed internal CD4+ T cell epitopes: whereas Q11 nanofibers required co-assembly of additional CD4+ T cell epitopes to be immunogenic, Coil29 nanofibers did not. Coil29 nanofibers also raised stronger germinal center B cell responses and follicular helper T cell (Tfh) responses relative to Q11 nanofibers, likely facilitating the improvement of the antibody response. These findings illustrate design strategies for improving humoral responses raised by self-assembled peptide nanofibers.
Incorporation of Pt Particles in Boron-Doped Diamond Thin Films Applications in Electrocatalysis (1999)

Polycrystalline, boron‐doped diamond (BDD) thin films were codeposited with particles on either conducting or substrates. These dimensionally stable and corrosion‐resistant electrodes consisted of well‐faceted microcrystallites with dispersed particles incorporated into the surface region. The metal particles were well anchored and ranged from 10 to in diam. The active metal loading was in the range of 200 to (diamond electrode geometric area) however, the real catalyst loading was estimated to be near . Importantly, the particles at the surface were in electronic communication with the current collecting substrate through the BDD matrix, and they were electroactive for underpotential deposition of hydrogen and oxidation of methanol. The dispersed particles were extremely stable as no loss in the activity was observed after 2000 potential cycles between the oxygen and hydrogen evolution regimes in . Characterization results are reported. ©2000 The Electrochemical Society
Fast cell search using I/Q multiplexed code in asynchronous DS/CDMA cellular systems (2002)

For wireless multimedia services in cellular systems, it is desirable to asynchronously operate the cell sites because of flexible system deployment from outdoors to indoors. For this, we should be able to minimize the cell search time which is much longer than in case of synchronous operation. A new code assignment scheme is proposed for the forward pilot channel using short spreading codes, in which a group code is assigned to the in-phase (I) pilot channel of all cells belonging to the group, and a cell-specific code is assigned to the quadrature (Q) pilot channel of each cell in the group. Based on the code assignment, the mobile station first searches a group code by processing the I channel, and then detect a cell-specific code from the Q channel, resulting in fast cell search. As a decision algorithm, a SPRT (sequential probability ratio test) is used to further reduce the acquisition time of the I/Q multiplexed code. It is demonstrated through simulation that cell search can be finished in less than about 200 ms at 90% of the locations when 8 group codes and 64 cell-specific codes are assigned to 512 cell sites.
A Multi-Criteria Simulation Framework for Civil Aircraft Trajectory Optimisation (2010)

Over the past few years, great concern has been raised about the impact of commercial aviation on the environment. In a Business As Usual approach, the expected growth in air traffic is going to affect climate change even more unless mitigation policies are devised and implemented. Although there is a tendency to focus on long-term technological solutions and breakthroughs, short-term improvements applicable to existing aircraft/engine configurations are also very important to fully realise the benefits of new technologies. Aircraft trajectory optimisation presents the opportunity to effectively reduce fuel consumption and pollutants emitted providing a feasible short-term strategy to be applied to the existing aircraft fleet. The present study focuses on preliminary results obtained using a multi-disciplinary aircraft trajectory optimisation simulation framework. Three in-house computational models are implemented in the framework to model the aircraft and engine performance, as well as to predict the level of gaseous emissions produced. A commercially available optimiser is integrated within the framework to analyse and optimise single flight path elements (e.g., climb), as well as the entire flight profile. For the purpose of this study, the climb and the whole flight profile are divided in four and eight segments respectively. Trajectory optimisation processes are then carried out in order to minimise three different objective functions: flight time, fuel burned, and mass of oxides of nitrogen (NOx) emitted. The results of the trajectory optimisation processes performed confirm the validity, effectiveness, and flexibility of the methodology proposed. In future, it is expected that these types of approaches are utilised to efficiently compute complete, optimum and ‘greener’ aircraft trajectories, which help to minimise the impact of commercial aviation on the environment. Other computational models that simulate several other aspects such as aircraft and engine noise, weather conditions and contrails formation, among others, need to be also included in the optimisation processes.
Sharing information in time-division duplexing channels: A network coding approach (2009)

We study random linear network coding for time-division duplexing channels for sharing information between nodes. We assume a packet erasure channel with nodes that cannot transmit and receive information simultaneously. Each node will act as both a sender of its own information and a receiver for the information of the other nodes. When a node acts as the sender, it transmits coded data packets back-to-back before stopping to wait for the receivers to acknowledge the number of degrees of freedom, if any, that are required to decode correctly the information. This acknowledgment comes in the header of the coded packets that are sent by the other nodes. We study the mean time to complete the sharing process between the nodes. We provide a simple algorithm to compute the number of coded packets to be sent back-to-back depending on the state of the system. We present numerical results for the case of two nodes sharing data and show that the mean completion time of our scheme is close to the performance of a full duplex network coding scheme and can outperform full duplex schemes with no coding.
Synthesis and some pharmacological properties of potent and selective antagonists of the vasopressor (V1-receptor) response to arginine-vasopressin (1992)

We report the solid-phase synthesis of eight position-9-modified analogues of the potent V1-receptor antagonist of arginine-vasopressin, [1-(beta-mercapto-beta,beta-pentamethylenepropionic acid),2-O-methyltyrosine]arginine-vasopressin (d(CH2)5Tyr(Me)AVP) (1-8) and five position-9-modified analogues of the closely related beta,beta-dimethyl less potent V1 antagonist, [1-deaminopenicillamine,2-O-methyltyrosine]arginine-vasopressin (dPTyr(Me)AVP) (9-13). In d(CH2)5Tyr(Me)AVP the C-terminal Gly-NH2 was replaced by (1) ethylenediamine (Eda), (2) methylamine (NHMe), (3) Ala-NH2, (4) Val-NH2, (5) Arg-NH2, (6) Thr-NH2, (7) Gly-Eda, (8) Gly-N-butylamide (Gly-NH-Bu); in dPTyr(Me)AVP the C-terminal Gly-NH2 was replaced by (9) Ala-NH2, (10) Val-NH2, (11) Thr-NH2, (12) Arg-NH2, and (13) Tyr-NH2. All 13 analogues were tested for agonistic and antagonistic activities in in vivo rat vasopressor (V1-receptor) and rat antidiuretic (V2-receptor) assays. They exhibit no evident vasopressor agonism. All modifications in both antagonists were well-tolerated with excellent retention of V1 antagonism and striking enhancements in anti-V1/anti-V2 selectivity. With anti-V1 pA2 values of 8.75, 8.73, 8.86, and 8.78, four of the analogues of d-(CH2)5Tyr(Me)AVP (1-3 and 6) are equipotent with d(CH2)5Tyr(Me)AVP (anti-V1 pA2 = 8.62) but retain virtually none of the V2 agonism of d(CH2)5Tyr(Me)AVP. They are in fact weak V2 antagonists and strong V1 antagonists with greatly enhanced selectivity for V1 receptors relative to that of d(CH2)5Tyr(Me)AVP. With anti-V1 pA2 values respectively of 8.16, 8.05, 8.04, 8.52, and 8.25, all five analogues (9-13) of dPTyr(Me)AVP are at least as potent V1 antagonists as dPTyr(Me)AVP (pA2 = 7.96) and three of these (9, 12, 13) actually show enhanced V1 antagonism over that of dPTyr(Me)AVP. In fact, the Arg-NH2(9) analogue (12) is almost equipotent with d(CH2)5Tyr(Me)AVP. These new V1 antagonists are potentially useful as pharmacological tools for studies on the cardiovascular roles of AVP. Furthermore the analogues of dPTyr(Me)AVP may be useful in studies on the role(s) of AVP in the V1b-receptor-mediated release of ACTH from corticotrophs.
A dye scattering method for holographic endoscopy through optical fibers (1988)

A method is described detailing the holographic recording of stained tissue. The device used to make the holographic recordings as well as the staining procedures, the use of different illuminating wavelengths, and the method of contact recording holography are discussed. Results of this method are presented showing its ability to resolve images of tissue on the cellular level. Conclusions are drawn on the methods applications for basic and clinical medical research.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Optical Coherence Tomography Analysis Based Prediction of Humphrey 24-2 Visual Field Thresholds in Patients With Glaucoma (2017)

The proposed RGC-AC optimized predictive algorithm based on 9-field OCT image analysis and the RGC-AC concept is superior to previous methods and its performance is close to the reproducibility of HVF 24-2.
Self-Assembly of a Sugar-Based Gelator in Water:  Its Remarkable Diversity in Gelation Ability and Aggregate Structure (2001)

A new sugar-based gelator 1 was synthesized, and its gelation ability was evaluated in organic solvents and water. Very surprisingly, 1 was found to gelate organic solvents as well as water, indicating that 1 can act as an amphiphilic gelator. We characterized on superstructures of an aqueous gel from 1 using SEM, TEM, NMR, IR, and XRD. The aqueous gel 1 formed a three-dimensional network with 20−500 nm diameter puckered fibrils. In addition, the chiral aggregate was found to be largely twisted helical ribbons with ca. 85 nm width, ca. 315 nm pitch, and up to several micrometer length, whose helicity was exclusively left-handed. XRD diagrams indicate that an aqueous gel 1 maintains a bilayered structure with 2.90 nm long-range spacing. This gives the first example of the formation of well ordered bilayer-based aqueous gel. The XRD, FT-NMR, and FT-IR results suggested that the aqueous gel 1 is stabilized by a combination of the hydrogen bonding, π−π interactions, and hydrophobic forces.
Human monoclonal antibodies and engineered antibody domains as HIV-1 entry inhibitors (2009)

The efficacy of the anti-HIV-1 therapy is significantly compromised by resistance to the currently used US Food and Drug Administration-approved antiretroviral drugs, which suggests an urgent need to develop novel classes of potent inhibitors. Several broadly cross-reactive neutralizing human monoclonal antibodies are highly effective against HIV-1 infection in vitro, but their administration to HIV-1-infected humans has only resulted in modest antiviral effects. Engineered human antibody fragments, dAbs, could be more potent because of their small size (about 10-fold smaller than that of an IgG), which allows targeting of highly conserved structures on the HIV-1 envelope glycoprotein that are not accessible by full-size antibodies and relatively efficient penetration into the densely packed lymphoid environment in which HIV-1 mostly replicates and spreads.
Passive mode locking of a Ti:Al2O3 laser with a nonlinear coupled cavity (1989)

A Ti:Al2O3 laser is passively mode-locked with the use of an external cavity containing a nonlinear medium. No active modulation of the laser gain or loss is required for ultrashort pulse generation. The mode-locked output is a continuous train of chirped 2 ps pulses which may be dispersively compensated with a grating pair of obtain 560 fs pulses. For comparison purposes, the Ti:Al2O3 laser is actively mode-locked to obtain 60 ps pulses, and the pulses are shortened using the nonlinear external cavity to obtain chirped 2 ps pulses.
Moldable thermoplastic elastomers: Electrical worker gloves and sleeves (1996)

Abstract A series of blends of styrene‐isoprene‐styrene block copolymers and ultralow density polyethylenes were evaluated for mechanical and electrical properties. A number of these blends were found to be suitable for use as moldable gloves for electrical workers. The mechanical properties exceeded those required of natural rubber solvent dipped gloves. The electrical properties were also found to satisfactorily meet the required levels of voltage and current resistance. Of particular importance were the blends in which the SIS component comprised the matrix phase. These blends exhibited low values of hardness, which made the resulting material highly flexible and compliant. The addition of polyethylene to the SIS elastomer reduced the surface tack to an acceptable level, without negatively affecting the other key properties of the elastomer. Good interfacial compatibility was found at low levels of each component in the other.
Modification of Platinum(II) Antitumor Complexes with Sulfur Ligands. 1. Synthesis, Structure, and Spectroscopic Properties of Cationic Complexes of the Types [PtCl(diamine)(L)]NO<sub>3</sub>and [{PtCl(diamine)}<sub>2</sub>(L-L)](NO<sub>3</sub>)<sub>2</sub>(L = Monofunctional Thiourea Derivative; L-L = Bifunctional Thiourea Derivative) (1998)

A new class of mono- and dinuclear platinum(II) complexes is described that derives from the cisplatin analogues [Pt(en)Cl2] and [Pt(dach)Cl2] (en = 1,2-ethanediamine, dach = racemic trans-1,2-cyclohexanediamine). The selective substitution of one chloro ligand in these species by 1,1,3,3-tetramethylthiourea (tmtu), which requires abstraction of chloride with silver salt in DMF, gives [PtCl(en)(tmtu)]NO3 (1) and [PtCl(dach)(tmtu)]NO3 (2). Similarly, reactions employing the novel bifunctional thiourea derivatives C2H4(NMeCSNMe2)2 (3) and C6H12(NMeCSNMe2)2 (4) yield the dinuclear complexes [{Pt(en)Cl}2(μ-3-S,S‘)](NO3)2 (5) and [{Pt(en)Cl}2(μ-4-S,S‘)](NO3)2·0.5EtOH (6), respectively. The compounds were characterized by 1H, 13C, and 195Pt NMR spectroscopy, elemental analyses, and IR data. 195Pt chemical shifts in the −2895 to −2929 ppm region confirm the mixed-donor [PtN2ClS] coordination for 1, 2, 5, and 6 and thiourea-S coordination in all cases. The single-crystal X-ray structures of 2−4 have been determined. 2: monoclinic, space group P21/n, a = 10.804 Å, b = 16.221 Å, c = 21.789 Å, β = 102.16(1)°, Z = 8. 3: monoclinic, space group P21/n, a = 12.787(2) Å, b = 6.250(1) Å, c = 17.777(3) Å, β = 98.21(1)°, Z = 4. 4: monoclinic, space group P21/n, a = 11.097(3) Å, b = 13.717 Å, c = 11.925 Å, β = 97.61(2)°, Z = 4. The Pt−S distance in 2 (2.285(2) Å, mean) is in accordance with the magnitude of shielding found for the 195Pt core and suggests weak π-acceptor properties of tmtu. The bifunctional thiourea derivatives 3 and 4 adopt highly elongated conformations in the solid state where the sulfur atoms and the n-(CH2)n (n = 2, 6) linkers are Z-oriented. Force field calculations on 3 and 4 imply that the Z-form should be the preferred conformer for the thiourea groups in solution. 1H NMR spectra indicate a dynamic equilibrium of different rotamers due to low barriers of rotation within the thiourea moieties in free and coordinated 3 and 4. It is suggested that the steric and electronic effects of the peralkylated thiourea derivatives in 1, 2, 5, and 6 may modulate the affinity of the complexes for biomolecules.
Multi-Channel Remote Photoplethysmography Correspondence Feature for 3D Mask Face Presentation Attack Detection (2021)

With the advancement of 3D printing technologies, 3D mask presentation attack becomes a critical challenge in face recognition. To tackle the 3D mask presentation attack detection (PAD), remote Photoplethysmography (rPPG) is employed as an intrinsic detection cue which is independent of the mask material and appearance quality. Although the effectiveness of existing rPPG-based methods has been verified, they may not be robust enough when rPPG signals are contaminated by noise. To identify the heartbeat information from the noisy raw rPPG signals, we propose a new 3D mask PAD feature, multi-channel rPPG correspondence feature (MCCFrPPG) with the global noise-aware template learning and verification framework. To further boost the discriminability, temporal variation of the rPPG signal is considered and extracted through the multi-channel time-frequency analysis scheme. This paper also extends HKBU-MARs V2 dataset with more customized high-quality masks and increases the number of videos by two times. Comprehensive experiments were performed on existing 3D mask datasets and the extended HKBU-MARs V2+, which totally covers 3 types of masks, 12 different light settings and 6 cameras. The results not only justify the effectiveness and robustness of the proposed MCCFrPPG on 3D mask attacks but also indicate its potential on handling the replay attack with camera motion and dim light.
Typing on an Invisible Keyboard (2018)

A virtual keyboard takes a large portion of precious screen real estate. We have investigated whether an invisible keyboard is a feasible design option, how to support it, and how well it performs. Our study showed users could correctly recall relative key positions even when keys were invisible, although with greater absolute errors and overlaps between neighboring keys. Our research also showed adapting the spatial model in decoding improved the invisible keyboard performance. This method increased the input speed by 11.5% over simply hiding the keyboard and using the default spatial model. Our 3-day multi-session user study showed typing on an invisible keyboard could reach a practical level of performance after only a few sessions of practice: the input speed increased from 31.3 WPM to 37.9 WPM after 20 - 25 minutes practice on each day in 3 days, approaching that of a regular visible keyboard (41.6 WPM). Overall, our investigation shows an invisible keyboard with adapted spatial model is a practical and promising interface option for the mobile text entry systems.
Enhancement of laser-induced optical breakdown using metal/dendrimer nanocomposites (2003)

Summary from only given. We demonstrate that one can notably alter the laser induced optical breakdown (LIOB) threshold of a material by incorporating metal nanoparticles, which significantly enhance the electric field localized at their immediate surroundings. We used dendrimer nanocomposites, a novel class of nanomaterials, as a model system.