Tattoolike Polyaniline Microparticle-Doped Gold Nanowire Patches as Highly Durable Wearable Sensors

Wearable and highly sensitive strain sensors are essential components of electronic skin for future biomonitoring and human machine interfaces. Here we report a low-cost yet efficient strategy to dope polyaniline microparticles into gold nanowire (AuNW) films, leading to 10 times enhancement in conductivity and ∼8 times improvement in sensitivity. Simultaneously, tattoolike wearable sensors could be fabricated simply by a direct "draw-on" strategy with a Chinese penbrush. The stretchability of the sensors could be enhanced from 99.7% to 149.6% by designing curved tattoo with different radius of curvatures. We also demonstrated roller coating method to encapusulate AuNWs sensors, exhibiting excellent water resistibility and durability. Because of improved conductivity of our sensors, they can directly interface with existing wireless circuitry, allowing for fabrication of wireless flexion sensors for a human finger-controlled robotic arm system.

The Saccharomyces cerevisiae TIF6 gene encoding translation initiation factor 6 is required for 60S ribosomal subunit biogenesis

Eukaryotic translation initiation factor 6 (eIF6), a monomeric protein of about 26 kDa, can bind to the 60S ribosomal subunit and prevent its association with the 40S ribosomal subunit. In Saccharomyces cerevisiae, eIF6 is encoded by a single-copy essential gene. To understand the function of eIF6 in yeast cells, we constructed a conditional mutant haploid yeast strain in which a functional but a rapidly degradable form of eIF6 fusion protein was synthesized from a repressible GAL10 promoter. Depletion of eIF6 from yeast cells resulted in a selective reduction in the level of 60S ribosomal subunits, causing a stoichiometric imbalance in 60S-to-40S subunit ratio and inhibition of the rate of in vivo protein synthesis. Further analysis indicated that eIF6 is not required for the stability of 60S ribosomal subunits. Rather, eIF6-depleted cells showed defective pre-rRNA processing, resulting in accumulation of 35S pre-rRNA precursor, formation of a 23S aberrant pre-rRNA, decreased 20S pre-rRNA levels, and accumulation of 27SB pre-rRNA. The defect in the processing of 27S pre-rRNA resulted in the reduced formation of mature 25S and 5.8S rRNAs relative to 18S rRNA, which may account for the selective deficit of 60S ribosomal subunits in these cells. Cell fractionation as well as indirect immunofluorescence studies showed that c-Myc or hemagglutinin epitope-tagged eIF6 was distributed throughout the cytoplasm and the nuclei of yeast cells.

Nanoparticle Superlattices: The Roles of Soft Ligands

Nanoparticle superlattices are periodic arrays of nanoscale inorganic building blocks including metal nanoparticles, quantum dots and magnetic nanoparticles. Such assemblies can exhibit exciting new collective properties different from those of individual nanoparticle or corresponding bulk materials. However, fabrication of nanoparticle superlattices is nontrivial because nanoparticles are notoriously difficult to manipulate due to complex nanoscale forces among them. An effective way to manipulate these nanoscale forces is to use soft ligands, which can prevent nanoparticles from disordered aggregation, fine-tune the interparticle potential as well as program lattice structures and interparticle distances - the two key parameters governing superlattice properties. This article aims to review the up-to-date advances of superlattices from the viewpoint of soft ligands. We first describe the theories and design principles of soft-ligand-based approach and then thoroughly cover experimental techniques developed from soft ligands such as molecules, polymer and DNA. Finally, we discuss the remaining challenges and future perspectives in nanoparticle superlattices.

Plasmonic core-shell nanoparticles for SERS detection of the pesticide thiram: size- and shape-dependent Raman enhancement

We systematically investigated the size- and shape-dependent SERS activities of plasmonic core-shell nanoparticles towards detection of the pesticide thiram. Monodisperse Au@Ag nanocubes (NCs) and Au@Ag nanocuboids (NBs) were synthesized and their Ag shell thickness was precisely adjusted from ∼1 nm to ∼16 nm. All these nanoparticles were used as SERS substrates for thiram detection, and the Raman intensities with three different lasers (514 nm, 633 nm and 782 nm) were recorded and compared. Our results clearly show that: (1) the excitation wavelength discriminated particle shapes regardless of particle sizes, and the maximized Raman enhancement was observed when the excitation wavelength approaches the SERS peak (provided there is significant local electric field confinement on the plasmonic nanostructures at that wavelength); (2) at the optimized laser wavelength, the maximum Raman enhancement was achieved at a certain threshold of particle size (or silver coating thickness). By exciting particles at their optimized sizes with the corresponding optimized laser wavelengths, we achieved a detection limit of roughly around 100 pM and 80 pM for NCs and NBs, respectively.

The Saccharomyces cerevisiae homologue of mammalian translation initiation factor 6 does not function as a translation initiation factor

Eukaryotic translation initiation factor 6 (eIF6) binds to the 60S ribosomal subunit and prevents its association with the 40S ribosomal subunit. The Saccharomyces cerevisiae gene that encodes the 245-amino-acid eIF6 (calculated Mr 25,550), designated TIF6, has been cloned and expressed in Escherichia coli. The purified recombinant protein prevents association between 40S and 60S ribosomal subunits to form 80S ribosomes. TIF6 is a single-copy gene that maps on chromosome XVI and is essential for cell growth. eIF6 expressed in yeast cells associates with free 60S ribosomal subunits but not with 80S monosomes or polysomal ribosomes, indicating that it is not a ribosomal protein. Depletion of eIF6 from yeast cells resulted in a decrease in the rate of protein synthesis, accumulation of half-mer polyribosomes, reduced levels of 60S ribosomal subunits resulting in the stoichiometric imbalance in the 40S/60S subunit ratio, and ultimately cessation of cell growth. Furthermore, lysates of yeast cells depleted of eIF6 remained active in translation of mRNAs in vitro. These results indicate that eIF6 does not act as a true translation initiation factor. Rather, the protein may be involved in the biogenesis and/or stability of 60S ribosomal subunits.

Giant plasmene nanosheets, nanoribbons, and origami

We introduce Plasmene- in analogy to graphene-as free-standing, one-particle-thick, superlattice sheets of nanoparticles ("meta-atoms") from the "plasmonic periodic table", which has implications in many important research disciplines. Here, we report on a general bottom-up self-assembly approach to fabricate giant plasmene nanosheets (i.e., plasmene with nanoscale thickness but with macroscopic lateral dimensions) as thin as ∼40 nm and as wide as ∼3 mm, corresponding to an aspect ratio of ∼75,000. In conjunction with top-down lithography, such robust giant nanosheets could be milled into one-dimensional nanoribbons and folded into three-dimensional origami. Both experimental and theoretical studies reveal that our giant plasmene nanosheets are analogues of graphene from the plasmonic nanoparticle family, simultaneously possessing unique structural features and plasmon propagation functionalities.

Two-Dimensional Bipyramid Plasmonic Nanoparticle Liquid Crystalline Superstructure with Four Distinct Orientational Packing Orders

Anisotropic plasmonic nanoparticles have been successfully used as constituent elements for growing ordered nanoparticle arrays. However, orientational control over their spatial ordering remains challenging. Here, we report on a self-assembled two-dimensional (2D) nanoparticle liquid crystalline superstructure (NLCS) from bipyramid gold nanoparticles (BNPs), which showed four distinct orientational packing orders, corresponding to horizontal alignment (H-NLCS), circular arrangement (C-NLCS), slanted alignment (S-NLCS), and vertical alignment (V-NLCS) of constituent particle building elements. These packing orders are characteristic of the unique shape of BNPs because all four packing modes were observed for particles with various sizes. Nevertheless, only H-NLCS and V-NLCS packing orders were observed for the free-standing ordered array nanosheets formed from a drying-mediated self-assembly at the air/water interface of a sessile droplet. This is due to strong surface tension and the absence of particle-substrate interaction. In addition, we found the collective plasmonic coupling properties mainly depend on the packing type, and characteristic coupling peak locations depend on particle sizes. Interestingly, surface-enhanced Raman scattering (SERS) enhancements were heavily dependent on the orientational packing ordering. In particular, V-NLCS showed the highest Raman enhancement factor, which was about 77-fold greater than the H-NLCS and about 19-fold greater than C-NLCS. The results presented here reveal the nature and significance of orientational ordering in controlling plasmonic coupling and SERS enhancements of ordered plasmonic nanoparticle arrays.

Function of eukaryotic translation initiation factor 1A (eIF1A) (formerly called eIF-4C) in initiation of protein synthesis

We have used an efficient in vitro translation initiation system to show that the mammalian 17-kDa eukaryotic initiation factor, eIF1A (formerly designated eIF-4C), is essential for transfer of the initiator Met-tRNAf (as Met-tRNAf.eIF2.GTP ternary complex) to 40 S ribosomal subunits in the absence of mRNA to form the 40 S preinitiation complex (40 S.Met-tRNAf.eIF2.GTP). Furthermore, eIF1A acted catalytically in this reaction to mediate highly efficient transfer of the Met-tRNAf.eIF2.GTP ternary complex to 40 S ribosomal subunits. The 40 S complex formed was free of eIF1A indicating that its role in 40 S preinitiation complex formation is not to stabilize the binding of Met-tRNAf to 40 S ribosomes. Additionally, the eIF1A-mediated 40 S initiation complex formed in the presence of AUG codon efficiently joined 60 S ribosomal subunits in an eIF5-dependent reaction to form a functional 80 S initiation complex. In contrast to other reports, we found that eIF1A plays no role either in the subunit joining reaction or in the generation of ribosomal subunits from 80 S ribosomes. Our results indicate that the major function of eIF1A is to mediate the transfer of Met-tRNAf to 40 S ribosomal subunits to form the 40 S preinitiation complex.

Molecular cloning and functional expression of a human cDNA encoding translation initiation factor 6

Eukaryotic translation initiation factor 6 (eIF6) binds to the 60S ribosomal subunit and prevents its association with the 40S ribosomal subunit. In this paper, we devised a procedure for purifying eIF6 from rabbit reticulocyte lysates and immunochemically characterized the protein by using antibodies isolated from egg yolks of laying hens immunized with rabbit eIF6. By using these monospecific antibodies, a 1.096-kb human cDNA that encodes an eIF6 of 245 amino acids (calculated Mr 26,558) has been cloned and expressed in Escherichia coli. The purified recombinant human protein exhibits biochemical properties that are similar to eIF6 isolated from mammalian cell extracts. Database searches identified amino acid sequences from Saccharomyces cerevisiae, Drosophila, and the nematode Caenorhabditis elegans with significant identity to the deduced amino acid sequence of human eIF6, suggesting the presence of homologues of human eIF6 in these organisms.

Bifunctional plasmonic-magnetic particles for an enhanced microfluidic SERS immunoassay

Surface-Enhanced Raman Scattering (SERS) is emerging as a promising strategy for the quantification of immunoglobulin G (IgG) due to its inherent high sensitivity and specificity; however, it remains challenging to integrate SERS detection with a microfluidic system in a simple, efficient and low-cost manner. Here, we report on a novel bifunctional plasmonic-magnetic particle-based immunoassay, in which plasmonic nanoparticles act as soluble SERS immunosubstrates, whereas magnetic particles are for promoting micromixing in a microfluidic chip. With this novel SERS immunosubstrate in conjunction with the unique microfluidic system, we could substantially reduce the assay time from 4 hours to 80 minutes as well as enhance the detection specificity by about 70% in comparison to a non-microfluidic immunoassay. Compared to previous microfluidic SERS systems, our strategy offers a simple microfluidic chip design with only one well for mixing, washing and detection.

Characterization of multiple mRNAs that encode mammalian translation initiation factor 5 (eIF-5)

Eukaryotic translation initiation factor 5 (eIF-5) interacts with the 40 S initiation complex (40S.mRNA.MettRNAf.eIF-2.GTP) to promote the hydrolysis of bound GTP with the concomitant joining of the 60 S ribosomal subunit to the 40 S initiation complex to form a functional 80 S initiation complex. In this paper, the multiple mRNAs that encode mammalian eIF-5 have been characterized. In rat tissues, three major eIF-5 mRNAs of 3.5, 2.8, and 2.2 kilobases in length are detected. All major eIF-5 mRNAs are initiated from a single transcription initiation site, contain identical 5'-untranslated and coding regions, but differ from one another only in the length of their 3'-untranslated regions. The different lengths of the 3'-untranslated region of eIF-5 mRNAs are generated by the use of alternative polyadenylation signals. Additionally, we demonstrate tissue-specific variations in eIF-5 mRNA expression as well as preference for polyadenylation sites. These results should lead to increased understanding of the regulation of eIF-5 gene expression.

Free-Standing Bilayered Nanoparticle Superlattice Nanosheets with Asymmetric Ionic Transport Behaviors

Natural cell membranes can directionally and selectively regulate the ion transport, which is critical for the functioning of living cells. Here, we report on the fabrication of an artificial membrane based on an asymmetric nanoparticle superlattice bilayered nanosheet, which exhibits similar ion transport characteristics. The superlattice nanosheets were fabricated via a drying-mediated self-assembly of polystyrene-capped gold nanoparticles at the liquid-air interface. By adopting a layer-by-layer assembly process, an asymmetric nanomembrane could be obtained consisting of two nanosheets with different nanoparticle size. The resulting nanomembranes exhibit an asymmetric ion transport behavior, and diode-like current-voltage curves were observed. The asymmetric ion transport is attributed to the cone-like nanochannels formed within the membranes, upon which a simulation map was established to illustrate the relationship between the channel structure and the ionic selectivity, in consistency with our experimental results. Our superlattice nanosheet-based design presents a promising strategy for the fabrication of next-generation smart nanomembranes for rationally and selectively regulating the ion transport even at a large ion flux, with potential applications in a wide range of fields, including biosensor devices, energy conversion, biophotonics, and bioelectronics.

Two-dimensional gold trisoctahedron nanoparticle superlattice sheets: self-assembly, characterization and immunosensing applications

Nanoparticles were called "artificial atoms" about two decades ago due to their ability to organize into regular lattices or supracrystals. Their self-assembly into free-standing, two-dimensional (2D) nanoparticle arrays enables the generation of 2D metamaterials for novel applications in sensing, nanophotonics and energy fields. However, their controlled fabrication is nontrivial due to the complex nanoscale forces among nanoparticle building blocks. Here, we report a new type of 2D plasmonic superlattice from high-index gold trisoctahedron (TOH) nanoparticles. TOH is an anisotropic polyhedron with 24 facets and 14 vertices. By using polymer ligands in conjunction with drying-mediated self-assembly, we obtained highly ordered 2D superlattices as quantified by synchrotron based grazing-incidence small-angle X-ray scattering (GISAXS). The plasmonic properties were optimized by adjusting the ligand length and particle size. The excellent surface-enhanced Raman scattering (SERS) performance enables us to demonstrate TOH superlattices as uniform SERS immunosubstrates with a detection limit down to 1 pg ml^-1 and a dynamic range from 1 pg ml^-1 to 100 ng ml^-1.

Stretch of mammalian nerve in vitro: effect on compound action potentials

Stretch of nerve has been reported to decrease the amplitude of the compound action potential (CAP) with a complete block appearing in approximately 30 minutes. But for the most part, those experiments were carried out in vivo, and it is generally accepted that the failure of responses was due to a closure of vessels supplying the nerve with a resulting ischemia and anoxia. These studies were undertaken to determine if stretch of nerve has effects that are independent of interference with its vascular supply. In the studies, lengths of rat sciatic and dog peroneal nerves were removed and placed in a chamber supplied with oxygen in which their CAPs were continuously elicited and recorded. This in vitro preparation obviated interference with the nerve's metabolism on stretching. We have previously shown that the form change termed 'beading,' appearing within 10 seconds and reversing as quickly on relaxation, can be elicited with tensions of only several grams. We wished to determine if stretch adequate to produce beading could alter CAPs with the same rapidity. Tensions below 2 g had little effect. On applying tensions of 10-100 g, levels well above those needed to bead the fibers, both increases and decreases of CAP amplitude were seen. The changes occurred within 10 seconds of stretch application, the time at which beading arises with stretch. Although the decreases of CAP amplitudes could be accounted for by beading, the degree of CAP change did not correspond to the amount of tension applied. We hypothesize that the constrictions in the beaded fibers increase axial resistivity and diminish local currents so as to block conduction. The lack of an increasing degree of decreased CAP amplitude with increases in tension is ascribed to the inhibition of elongation offered by the collagen fibrils present in nerve. Collagenase applied to nerves allowed a further increase in length, producing a 'hyperbeading,' showing much longer lengths of beading constrictions on stretch. This would further increase axial resistance and is taken to account for the greater decreases of CAP amplitudes seen following collagenase treatment. To account for those cases where increases of CAP amplitude were seen on stretch, we hypothesize that stretch can also cause an increase in the excitability of the nodes. The outcome of stretch in any given nerve would be the resultant of two opposing actions; beading of the internodes causes a decrease of local currents leading to block of CAPs, while an increased excitability of the nodes acts to augment the responses.

DNA based strategy to nanoparticle superlattices

Over more than 20 years of development has led to the substantial progress made in the wet chemical synthesis of elementary nanoparticle building blocks including metal nanoparticles, quantum dots, and magnetic particles. However, it remains challenging to rationally assemble them into well-defined molecule-like architectures. DNA was first used to program nanomaterials synthesis in 1996, and more recently highly-ordered structures have emerged, including finite-number assemblies (nanoparticle molecules), regularly spaced nanoparticle chains (nanoparticle polymers) and extended two- and three-dimensional ordered arrays (nanoparticle superlattices). In this review, we largely focus on the use of DNA to grow nanoparticle superlattices. First, typical synthetic approaches and characterization methodologies for monodisperse nanoparticle building blocks used in DNA-based nanoparticle superlattices are described; secondly, the viable conjugation and characterization methods are discussed; finally, the three representative self-assembly strategies are introduced in detail.

Initial characterization of the effects of Aloe vera at a crayfish neuromuscular junction

This study examines the effects of Aloe vera on neurotransmission processes in a well-established invertebrate neuromuscular junction preparation. We studied concentration-response relationships of an Aloe vera extract on excitatory junctional potentials (EJPs) at the opener muscle of the dactyl in the first and second walking limbs of crayfish (Procambarus clarkii and simulans). We observed concentration-dependent depolarizations of the muscle fibre membrane resting potential, depression of EJP amplitudes and an increase in latency to onset of the EJP following electrical stimulation of the isolated excitatory axon in the meropodite. These effects occurred with Aloe concentrations within the 1%-10% (wt-vol) range. Effects of lower concentrations, ranging to a minimum of 0.01% were equivocal. The effects of Aloe were at least partially, and in a majority of cases totally, reversible. EJPs reduced by Aloe could be restored by increasing the nerve stimulation amplitude. This, along with the latency increase, suggests a depression of action potential generation and conduction. The results provide a preliminary characterization of the effects of Aloe vera on the neurotransmission process and suggest that these effects may at least partially account for Aloe's analgesic and antiinflammatory effects. This study shows that the crayfish NMJ preparation should be useful for further elucidating the location(s) and mechanism(s) of action of Aloe on the nervous system.

2D Binary Plasmonic Nanoassemblies with Semiconductor n/p-Doping-Like Properties

The electronic, optical, thermal, and magnetic properties of an extrinsic bulk semiconductor can be finely tuned by adjusting its dopant concentration. Here, it is demonstrated that such a doping concept can be extended to plasmonic nanomaterials. Using two-dimensional (2D) assemblies of Au@Ag and Au nanocubes (NCs) as a model system, detailed experimental and theoretical studies are carried out, which reveal collective semiconductor n/p-doping-like plasmonic properties. A threshold doping concentration of Au@Ag NCs is observed, below which p-doping dominates and above which n-doping prevails. Furthermore, Au@Ag NC dopants can be converted into corresponding Au seed "voids" dopants by selectively removing Ag without changing the overall structural integrity. The results show that the plasmonic doping concept may serve as a general design principle guiding synthesis and assembly of plasmonic metamaterials for programmable optoelectronic devices.

Shape Transformation of Constituent Building Blocks within Self-Assembled Nanosheets and Nano-origami

Self-assembly of nanoparticles represents a simple yet efficient route to synthesize designer materials with unusual properties. However, the previous assembled structures whether by surfactants, polymer, or DNA ligands are "static" or "frozen" building block structures. Here, we report the growth of transformable self-assembled nanosheets which could enable reversible switching between two types of nanosheets and even evolving into diverse third generation nanosheet structures without losing pristine periodicity. Such in situ transformation of nanoparticle building blocks can even be achieved in a free-standing two-dimensional system and three-dimensional origami. The success in such in situ nanocrystal transformation is attributed to robust "plant-cell-wall-like" ion-permeable reactor arrays from densely packed polymer ligands, which spatially define and confine nanoscale nucleation/growth/etching events. Our strategy enables efficient fabrication of nanocrystal nanosheets with programmable building blocks for innovative applications in adaptive tactile metamaterials, optoelectronic devices, and sensors.

Characterization of Vibrio cholerae EIT or typing phage D10

The Vibrio cholerae EITor typing phage D10 was characterized. The adsorption kinetics of the phage on V. cholerae MAK757 strain were biphasic in nature. Intracellular growth was characterized by an eclipse period, latent period and burst size which were 20 min, 25 min and 80 particles per cell respectively. The phage yield was dependent on the concentration and time of addition of DNA synthesis inhibitors such as nalidixic acid and novobiocin, and RNA synthesis inhibitors such as rifampicin. The 32+/-0.2 kb linear double-stranded DNA molecule has unique termini. A restriction map of the phage DNA was constructed with the enzymes BamHI, HindIII and PstI.

P1801Multiple members with an isolated atrial septal defect phenomenon presented in a family with Holt-Oram syndrome

Background

Holt-Oram syndrome (HOS), characterized by upper limb malformations, congenital heart diseases (CHD) and/or cardiac conduction abnormalities, is an autosomal dominant disease. Almost all the HOS patients suffer from cardiac and limb abnormalities at the same time. Among them, atrial septal defect (ASD) is the most common cardiac anomaly. The unusual phenotype in a pedigree including multiple members with isolated ASD and a few with isolated limb deformity attracted attention.

Aim

To detect mutant genes of ASD in this pedigree and make a definitive diagnosis. To investigate the mutant type of the gene and illustrate the possible mechanism of heterogeneous phenotype.

Methods

Echocardiography, electrocardiography and physical examination were given to a four-generation Chinese HOS family. Of all 11 patients in this pedigree, eight patients had isolated ASD and one patient had isolated finger deformity. In addition, two patients suffered from both diseases (Figure. 1). Whole Exome Sequencing was performed on the proband and his relatives including three with ASD only, one with finger deformity only and one normal person. Sanger sequencing was performed on biological relatives in this pedigree to valid rare variants. Single nucleotide polymorphisms and insertions/deletions were identified using the GATK program. Pathogenicity was predicted in software like SIFT, Ployphen-2, MutationTaster and CADD_phred.

Results

An exon site mutation (c.100dupG:p.Ala34fs) of TBX5 was detected in all the patients of this pedigree. This mutation site is located in front of T-box and most probably leads to haploinsufficiency of TBX5 protein. In addition, only 42 variants (1 splicing single nucleotide variants (SNV), 15 insertions/deletions, 24 nonsynonymous SNVs, 1 stopgain SNVs and 1 unknown) were found in 29 genes, which are related to cardiac disease.

Figure 1

Conclusions

Our study revealed a mutation (c.100dupG:p.Ala34fs) of TBX5 and further demonstrated the possibility of HOS-related TBX5 mutation in patients with congenital ASD only. This study clarified the diagnosis of this pedigree, provided genetic counseling and promoted the prevention and treatment of HOS. Further research is needed on mechanisms that may lead to phenotypic variation between and within families, such as random monoallelic expression.

Acknowledgement/Funding

None

[Rapid microdose 14C-urea breath test for detection of Helicobacter pylori infection]

The purpose of this study was to develop and evaluate a rapid microdose 14C-urea breath test (14C-UBT) with a simplified protocol for detecting the infection of hilicobacter pylori (HP). 157 fasting patients who underwent endoscopy with histological examination and rapid urease test (RUT) were given a drink of 37 kBq of 14C-urea. Samples of breath carbon dioxide (1 mmol) were collected at baseline and 10, 20 and 30 min after administration by trapping in hyamine solution. 14C activity was measured by liquid scintillation counting. Results were expressed as cpm. Histolal examination and RUT were used as gold standard for the detection of HP infection. The cutoff value was selected as 200 cpm at 10 min. The results showed that the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 94.79%, 90.16%, 93.81%, 91.60% and 92.99% respectively. In this study, a 10 min, single sample, 37 kBq 14C-urea breath test for detection HP was developed. The test has good diagnostic accuracy with minimal radiation exposure and low cost. Thus, the authors considered the test to be reliable, safe, convenient and cost-effective to clinical use.