Dual-gate thin film transistor lactate sensors operating in the subthreshold regime.

Organic thin-film transistors (TFTs) with an electrochemically functionalized sensing gate are promising platforms for wearable health-monitoring technologies because they are light, flexible, and cheap. Achieving both high sensitivity and low power is highly demanding for portable or wearable devices. In this work, we present flexible printed dual-gate (DG) organic TFTs operating in the subthreshold regime with ultralow power and high sensitivity. The subthreshold operation of the gate-modulated TFT-based sensors not only increases the sensitivity but also reduces the power consumption. The DG configuration has deeper depletion and stronger accumulation, thereby further making the subthreshold slope sharper. We integrate an enzymatic lactate-sensing extended-gate electrode into the printed DG TFT and achieve exceptionally high sensitivity (0.77) and ultralow static power consumption (10 nW). Our sensors are successfully demonstrated in physiological lactate monitoring with human saliva. The accuracy of the DG TFT sensing system is as good as that of a high-cost conventional assay. The developed platform can be readily extended to various materials and technologies for high performance wearable sensing applications.

Spatiotemporal Measurement of Arterial Pulse Waves Enabled by Wearable Active-Matrix Pressure Sensor Arrays.

Wearable pressure sensors have demonstrated great potential in detecting pulse pressure waves on the skin for the noninvasive and continuous diagnosis of cardiac conditions. However, difficulties lie in positioning conventional single-point sensors on an invisible arterial line, thereby preventing the detection of adequate signal amplitude for accurate pulse wave analysis. Herein, we introduce the spatiotemporal measurements of arterial pulse waves using wearable active-matrix pressure sensors to obtain optimal pulse waveforms. We fabricate thin-film transistor (TFT) arrays with high yield and uniformity using inkjet printing where array sizes can be customizable and integrate them with highly sensitive piezoresistive sheets. We maximize the pressure sensitivity (16.8 kPa-1) and achieve low power consumption (101 nW) simultaneously by strategically modulating the TFT operation voltage. The sensor array creates a spatiotemporal pulse wave map on the wrist. The map presents the positional dependence of pulse amplitudes, which allows the positioning of the arterial line to accurately extract the augmentation index, a parameter for assessing arterial stiffness. The device overcomes the positional inaccuracy of conventional single-point sensors, and therefore, it can be used for medical applications such as arterial catheter injection or the diagnosis of cardiovascular disease in daily life.

Layout-to-Bitmap Conversion and Design Rules for Inkjet-Printed Large-Scale Integrated Circuits.

Digital inkjet printing (IJP) can greatly reduce the manufacturing cost and waste of flexible large-area electronics by adding micro-fine patterns onto plastic foils. Advanced system design using IJP has been limited by the lack of an electronic design automation (EDA) approach. An EDA approach based on a vector-based layout drawing requires parameterized IJP design rules. This study proposes a layout-to-bitmap (L2B) conversion procedure and line-based design rules that leverage the existing circuit layout EDA tools for advanced IJP designs. The L2B conversion is accomplished by optimizing the parameters of the horizontal and vertical lines by varying the drop spacings and platen temperatures. Next, the line-based layouts are converted to bitmap files which are used as IJP input data for printing multiple metal layers. This study systematically investigated the development of an IJP process employing Ag nanoparticles. The physical characteristics of the proposed process were evaluated based on theories concerning inkjet-printed bead formation. The design rules for fabricating printed thin-film transistor (TFT) circuits were documented. Documentation is the first step in creating an IJP process design kit for advanced electronics design. Using the optimized L2B conversion procedure and the design rules, a 10 × 10 array of printed organic TFTs was fabricated to demonstrate the reliability of the developed process. Additionally, the fabricated printed organic TFTs indicated that the proposed process could be extended to large-scale system designs.

A Flexible 3D Organic Preamplifier for a Lactate Sensor.

Organic transistors are promising platforms for wearable biosensors. However, the strategies to improve signal amplification have yet to be determined, particularly regarding biosensors that generate very weak signals. In this study, an organic voltage amplifier is presented for a lactate sensor on flexible plastic foil. The preamplifier is based on a 3D complementary inverter, which is achieved by vertically stacking complementary transistors with a shared gate between them. The shared gate is extended and functionalized with a lactate oxidase enzyme to detect lactate. The sensing device successfully detects the lactate concentration in the human sweat range (20-60 mm) with high sensitivity (6.82 mV mm-1 ) due to high gain of its amplification. The 3D integration process is cost-effective as it is solution-processable and doubles the number of transistors per unit area. The device presented in this study would pave the way for the development of high-gain noninvasive sweat lactate sensors that can be wearable.

Flexible Pressure-Sensitive Contact Transistors Operating in the Subthreshold Regime.

Organic thin-film transistor (TFT)-based pressure sensors have received huge attention for wearable electronic applications such as health monitoring and smart robotics. However, there still remains a challenge to achieve low power consumption and high sensitivity at the same time for the realization of truly wearable sensor systems where minimizing power consumption is significant because of limited battery run time. Here, we introduce a flexible pressure-sensitive contact transistor (PCT), a new type of pressure-sensing device based on organic TFTs for next-generation wearable electronic skin devices. The PCT consists of deformable S/D electrodes integrated on a staggered TFT. The deformable S/D electrodes were fabricated by embedding conducting single-walled carbon nanotubes on the surface of microstructured polydimethylsiloxane. Under pressure loads, the deformation of the electrodes on an organic semiconductor layer leads modulation of drain current from variation in both the channel geometry and contact resistance. By strategic subthreshold operation to minimize power consumption and increase the dominance of contact resistance because of gated Schottky contact, the PCT achieves both ultralow power consumption (order of 101 nW) and high sensitivity (18.96 kPa-1). Finally, we demonstrate a 5 × 5 active matrix PCT array on a 3 µm-thick parylene substrate. The device with ultralow power consumption and high sensitivity on a biocompatible flexible substrate makes the PCT promising candidate for next-generation wearable electronic skin devices.

Streptomyces panacagri sp. nov., isolated from soil of a ginseng field.

A Gram-positive, spore-forming, aerobic actinomycete, strain Gsoil 519T, was isolated from soil of a ginseng field of Pocheon province in South Korea. The closest phylogenetic relatives were Streptomyces marinus Sp080513GE-26T (97.94 % 16S rRNA gene sequence similarity), Streptomyces albiaxialis NRRL B-24327T (97.84 %), Streptomyces albus subsp. albus DSM 40313T (97.84 %), Streptomyces almquistii NBRC 13015T (97.81 %), Streptomyces gibsonii NBRC 15415T (97.81 %), Streptomyces rangoonensis NBRC 13078T (97.81 %), Streptomyces sodiiphilus YIM 80305T (97.77 %) and Streptomyces flocculus NBRC 13041T (97.67 %). The G+C content of the genomic DNA was 71.8 mol%. The chemotaxonomic data [MK-9(H6) and MK-9(H8) as the major menaquinones; ll-diaminopimelic acid as a component of the cell-wall peptidoglycan; ribose, xylose, mannose and glucose as the major cell-wall sugars; and anteiso-C15:0, iso-C15:0, iso-C17:0, anteiso-C17:0 and C16:0 as the major fatty acids] supported the affiliation of strain Gsoil 519T to the genus Streptomyces. The physiological and biochemical characteristics and the low level of DNA-DNA relatedness differentiated the isolate genotypically and phenotypically from recognized members of the genus Streptomyces. The isolate, therefore, represents a novel species, for which the name Streptomyces panacagri sp. nov. is proposed, with Gsoil 519T (=KCTC 19139T=DSM 41871T) as the type strain.

Paenibacillus sediminis sp. nov., a xylanolytic bacterium isolated from a tidal flat.

A Gram-positive, rod-shaped, xylanolytic, spore-forming bacterium, strain GTH-3(T), was isolated from a tidal flat adjacent to Ganghwa Island, Republic of Korea, and was characterized to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain GTH-3(T) was shown to belong to the family Paenibacillaceae, being most closely related to the type strains of Paenibacillus ginsengisoli (94.9 %), Paenibacillus anaericanus (94.8 %), Paenibacillus urinalis (94.4 %), Paenibacillus cookii (94.2 %), Paenibacillus alvei (94.1 %) and Paenibacillus chibensis (94.0 %). The G+C content of the genomic DNA of strain GTH-3(T) was 45.9±0.2 mol% (mean±sd). The major menaquinone was MK-7. The major fatty acids were anteiso-C(15:0) and iso-C(16:0). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phenotypic and chemotaxonomic data supported the affiliation of strain GTH-3(T) to the genus Paenibacillus. The results of physiological and biochemical tests allowed strain GTH-3(T) to be distinguished genotypically and phenotypically from recognized species of the genus Paenibacillus. Strain GTH-3(T) is therefore considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus sediminis sp. nov. is proposed. The type strain is GTH-3(T) ( = DSM 23491(T) = LMG 25635(T)).

Tumebacillus ginsengisoli sp. nov., isolated from soil of a ginseng field.

A gram-reaction-positive, rod-shaped, spore-forming bacterium, designated Gsoil 1105(T), was isolated from soil of a ginseng field in Pocheon Province in South Korea and characterized in order to determine its taxonomic position. Comparative analysis of the 16S rRNA gene sequence showed that the isolate belongs to the order Bacillales, showing the highest level of sequence similarity with respect to Tumebacillus permanentifrigoris Eur1 9.5(T) (94.6 %). The phylogenetic distances from other described species with validly published names within the order Bacillales were greater than 9.0 %. Strain Gsoil 1105(T) had a genomic DNA G+C content of 55.6 mol% and menaquinone 7 (MK-7) as the major respiratory quinone. The major fatty acids were iso-C(15 : 0) and anteiso-C(15 : 0). On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 1105(T) represents a novel species of the genus Tumebacillus, for which the name Tumebacillus ginsengisoli sp. nov. is proposed. The type strain is Gsoil 1105(T) ( = KCTC 13942(T)  = DSM 18389(T)).

Kaistia geumhonensis sp. nov. and Kaistia dalseonensis sp. nov., two members of the class Alphaproteobacteria.

Two strains, designated B1-1(T) and B6-8(T), were isolated from the Geumho River and the Dalseo Stream in Korea. Comparative 16S rRNA gene sequence analysis showed a clear affiliation of these two bacteria with the class Alphaproteobacteria, their closest relatives being Kaistia adipata KCTC 12095(T), Kaistia granuli KCTC 12575(T), Kaistia soli KACC 12605(T) and Kaistia terrae KACC 12910(T) with 16S rRNA gene sequence similarities of 95.3 -97.7 % to the two novel strains. Strains B1-1(T) and B6-8(T) shared a 16S rRNA gene sequence similarity value of 96.1 %. Cells of the two strains were Gram-reaction-negative, aerobic, non-motile, short rods or cocci. The predominant ubiquinone was Q-10. The major fatty acids were C(16 : 0,) C(18 : 1)ω7c, C(18 : 0) and C(19 : 0)ω8c cyclo for strain B1-1(T) and C(16 : 0,) C(18 : 1)ω7c, C(18 : 0), C(18 : 1) 2-OH, and C(19 : 0)ω8c cyclo for strain B6-8(T). The G+C contents of the genomic DNA of the strains B1-1(T) and B6-8(T) were 61.6 and 66.5 mol%, respectively. Based on the results of this polyphasic study, strains B1-1(T) ( = KCTC 12849(T) = DSM 18799(T)) and B6-8(T) ( = KCTC 12850(T) = DSM 18800(T)) represent two novel species of the genus Kaistia, for which the names Kaistia geumhonensis sp. nov. and Kaistia dalseonensis sp. nov. are proposed, respectively.

Novosphingobium sediminicola sp. nov. isolated from freshwater sediment.

A yellow-pigmented, Gram-negative, short rod-shaped, non-motile and non-spore-forming bacterial strain, designated HU1-AH51(T), was isolated from freshwater sediment and was characterized using a polyphasic approach, in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain HU1-AH51(T) was shown to belong to the genus Novosphingobium, showing the highest level of sequence similarity with respect to Novosphingobium resinovorum NCIMB 8767(T) (96.0 %), Novosphingobium naphthalenivorans TUT562(T) (96.0 %) and Novosphingobium panipatense SM16(T) (96.0 %). Strain HU1-AH51(T) had a genomic DNA G+C content of 62.6 mol% and Q-10 as the predominant respiratory quinone. Furthermore, the major polyamine component (spermidine) in the cytoplasm and the presence of sphingoglycolipids suggested that strain HU1-AH51(T) belongs to the family Sphingomonadaceae. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain HU1-AH51(T) represents a novel species of the genus Novosphingobium, for which the name Novosphingobium sediminicola sp. nov. is proposed. The type strain is HU1-AH51(T) ( = LMG 24320(T)  = KCTC 22311(T)).

Sphingobium vulgare sp. nov., isolated from freshwater sediment.

A Gram-negative, motile, non-spore-forming bacterial strain, designated HU1-GD12(T), was isolated from freshwater sediment. The strain was characterized by using a polyphasic approach in order to determine its taxonomic position. Comparative analysis of the 16S rRNA gene sequence showed that the isolate constituted a distinct branch within the genus Sphingobium, showing the highest level of sequence similarity with respect to Sphingobium ummariense RL-3(T) (96.2 %). Strain HU1-GD12(T) had a genomic DNA G+C content of 66.8 mol% and Q-10 as the predominant respiratory quinone. Furthermore, the major polyamine component (spermidine) in the cytoplasm and the presence of sphingoglycolipids suggested that strain HU1-GD12(T) belonged to the family Sphingomonadaceae. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain HU1-GD12(T) represents a novel species of the genus Sphingobium, for which the name Sphingobium vulgare sp. nov. is proposed. The type strain is HU1-GD12(T) (=LMG 24321(T)=KCTC 22289(T)).

Paenibacillus pocheonensis sp. nov., a facultative anaerobe isolated from soil of a ginseng field.

A Gram-positive, aerobic or facultatively anaerobic, rod-shaped, spore-forming bacterium, strain Gsoil 1138(T), was isolated from soil of a ginseng field in Pocheon Province, South Korea, and was characterized in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence analysis, strain Gsoil 1138(T) was shown to belong to the family Paenibacillaceae and was most closely related to the type strains of Paenibacillus chondroitinus (98.2 % similarity) and Paenibacillus alginolyticus (96.5 %). Levels of 16S rRNA gene sequence similarity between strain Gsoil 1138(T) and the type strains of other recognized species of the genus Paenibacillus were below 96.5 %. The G+C content of the genomic DNA of strain Gsoil 1138(T) was 52.1+/-0.2 mol% (mean+/-sd of three determinations). Phenotypic and chemotaxonomic data (MK-7 as the major menaquinone and anteiso-C(15 : 0) and iso-C(16 : 0) as the predominant fatty acids) supported the affiliation of strain Gsoil 1138(T) to the genus Paenibacillus. The results of DNA-DNA hybridization experiments and physiological and biochemical tests allowed strain Gsoil 1138(T) to be distinguished genotypically and phenotypically from recognized species of the genus Paenibacillus. Strain Gsoil 1138(T) is therefore considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus pocheonensis sp. nov. is proposed. The type strain is Gsoil 1138(T) (=KCTC 13941(T)=LMG 23404(T)).

Ferruginibacter alkalilentus gen. nov., sp. nov. and Ferruginibacter lapsinanis sp. nov., novel members of the family 'Chitinophagaceae' in the phylum Bacteroidetes, isolated from freshwater sediment.

Six Gram-negative, non-gliding, rod-shaped bacterial strains isolated from freshwater sediment were subjected to polyphasic analyses to determine their taxonomic positions. Analysis of the 16S rRNA gene sequences of the six strains revealed that they represent two separate genomic species in a new lineage within the phylum Bacteroidetes, related to members of the family 'Chitinophagaceae', in which they were most closely related to members of the genus Terrimonas (93.4-90.5 %). Two of the isolates, HU1-GD23(T) and HU1-HG42(T), had a sequence similarity of 96.2 %, with DNA G+C contents of 39.4 and 38.5 mol%, respectively. They possessed MK-7 as the predominant respiratory quinone and contained high amounts of iso-pentadecanoic acid and 3-hydroxy-iso-heptadecanoic acid in their cell envelopes, properties shared by members of the family 'Chitinophagaceae'. They were well differentiated from other members of the family 'Chitinophagaceae' by additional physiological and biochemical characteristics. In conclusion, strains HU1-GD23(T) (=KCTC 22306(T)=LMG 24312(T)) and HU1-HG42(T) (=KCTC 22305(T)=LMG 24324(T)) are considered to represent two novel species of a novel genus, Ferruginibacter gen. nov., for which the names Ferruginibacter alkalilentus sp. nov. and Ferruginibacter lapsinanis sp. nov., are proposed, respectively.

Burkholderia sediminicola sp. nov., isolated from freshwater sediment.

A Gram-negative, motile and rod-shaped bacterium, designated HU2-65W(T), was isolated from freshwater sediment. The strain possessed ubiquinone 8 as the predominant isoprenoid quinone and contained major amounts of omega7-cis-octadecenoic acid and hexadecanoic acid in its cell envelope, which are properties shared by members of the genus Burkholderia. On the basis of 16S rRNA gene sequence similarity, strain HU2-65W(T) was most closely related to the type strain of Burkholderia xenovorans (98.4 %). The DNA G+C content of strain HU2-65W(T) was 61.2 mol%, and DNA-DNA relatedness values to type strains of closely related species were found to be much lower than 70 %, indicating that the strain represents a separate genomic species within the genus Burkholderia. Strain HU2-65W(T) was also differentiated from other species of the genus by physiological and biochemical characteristics. Consequently, strain HU2-65W(T) is considered to represent a single, novel species of the genus Burkholderia, for which the name Burkholderia sediminicola sp. nov. is proposed, with the type strain HU2-65W(T) (=KCTC 22086(T) =LMG 24238(T)).

Paenibacillus ginsengisoli sp. nov., a novel bacterium isolated from soil of a ginseng field in Pocheon Province, South Korea.

A Gram-positive, aerobic or facultative anaerobic, motile, spore-forming bacterial strain, designated Gsoil 1638T, was isolated from a soil sample of a ginseng field in Pocheon province (South Korea), and was characterized taxonomically by using a polyphasic approach. It grew well on nutrient agar medium, utilized a fairly narrow spectrum of carbon sources and tolerated 10% NaCl. The isolate was positive for catalase and oxidase tests but negative for the degradation of macromolecules such as casein, collagen, starch, chitin, CM-cellulose, xylan and DNA. The G + C content of the genomic DNA was 50.7 mol%. The predominant isoprenoid quinone was menaquinone 7 (MK-7). The major fatty acids were anteiso-C15:0 (44%) and C16:0 (25%). Comparative 16S rRNA gene sequence analysis showed that strain Gsoil 1638T fell within the radiation of the cluster comprising Paenibacillus species and joined Paenibacillus anaericanus DSM 15890T with a bootstrap value of 100%. These two strains shared 99.5% 16S rRNA gene sequence similarity with each other. The phylogenetic distance from any other validly described species within the genus Paenibacillus was less than 96.2%. DNA-DNA relatedness value between strain Gsoil 1638T and its closest phylogenetic neighbor, Paenibacillus anaericanus, was 62%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 1638T (= KCTC 13931T = LMG 23406T = CCUG 52472T) was classified in the genus Paenibacillus as the type strain of a novel species, for which the name Paenibacillus ginsengisoli sp. nov. is proposed.

Bacillus panaciterrae sp. nov., isolated from soil of a ginseng field.

A Gram-positive, non-motile, endospore-forming bacterium, designated Gsoil 1517(T), was isolated from soil of a ginseng field in Pocheon Province (South Korea) and was characterized in order to determine its taxonomic position, using a polyphasic approach. It was found to rod-shaped and aerobic or facultatively anaerobic. It grew optimally at 30 degrees C and at pH 6.5-7.0. Comparative 16S rRNA gene sequence analysis showed that strain Gsoil 1517(T) forms a distinct phylogenetic lineage within the genus Bacillus, being related to Bacillus funiculus JCM 11201(T) (96.8 %). The strain showed less than 94.3 % sequence similarity with other Bacillus species. The G+C content of the genomic DNA was found to be 47.8 mol% and the predominant respiratory quinone was MK-7. The major fatty acids were iso-C(15 : 0) (42.4 %), anteiso-C(15 : 0) (17.4 %), iso-C(14 : 0) (9.7 %) and C(16 : 0) (6.0 %). On the basis of its phenotypic properties and phylogenetic distinctiveness, strain Gsoil 1517(T) represents a novel species of the genus Bacillus, for which the name Bacillus panaciterrae sp. nov. is proposed. The type strain is Gsoil 1517(T) (=KCTC 13929(T)=CCUG 52470(T)=LMG 23408(T)).

Brevibacillus ginsengisoli sp. nov., a denitrifying bacterium isolated from soil of a ginseng field.

A Gram-positive, rod-shaped, spore-forming bacterium, Gsoil 3088T, was isolated from soil from a ginseng field in Pocheon Province in South Korea and characterized in order to determine its taxonomic position. On the basis of 16S rRNA gene sequence similarity, strain Gsoil 3088T was shown to belong to the family Paenibacillaceae, being related to Brevibacillus centrosporus (96.6%), Brevibacillus borstelensis (96.3%), Brevibacillus parabrevis (96.1%), Brevibacillus formosus (96.1%), Brevibacillus brevis (96.1%) and Brevibacillus laterosporus (96.0%). The phylogenetic distances from other validly described species within the genus Brevibacillus were greater than 4.0% (i.e. there was less than 96.0% similarity). The G+C content of the genomic DNA was 52.1 mol%. Phenotypic and chemotaxonomic data (major menaquinone, MK-7; fatty acid profile, iso-C15:0, iso-C14:0 and anteiso-C15:0) supported the affiliation of strain Gsoil 3088T to the genus Brevibacillus. The results of physiological and biochemical tests allowed strain Gsoil 3088T to be distinguished genotypically and phenotypically from Brevibacillus species with validly published names. Strain Gsoil 3088T, therefore, represents a novel species of the genus Brevibacillus, for which the name Brevibacillus ginsengisoli sp. nov. is proposed. The type strain is Gsoil 3088T (=KCTC 13938T=LMG 23403T).

Paenibacillus panacisoli sp. nov., a xylanolytic bacterium isolated from soil in a ginseng field in South Korea.

A Gram-positive, facultatively anaerobic, motile, spore-forming bacterium, designated Gsoil 1411T, was isolated from soil of a ginseng field in Pocheon Province (South Korea) and was characterized using a polyphasic approach. Comparative analysis of 16S rRNA gene sequences revealed that strain Gsoil 1411T belongs to the family Paenibacillaceae, with closest sequence similarity to the type strains of Paenibacillus xylanilyticus (95.7%), Paenibacillus illinoisensis (95.2%) and Paenibacillus pabuli (94.8%). Strain Gsoil 1411T showed less than 94% sequence similarity to the type strains of other recognized members of the genus Paenibacillus. In addition, the presence of MK-7 as the major menaquinone, anteiso-C15:0 as a major fatty acid (44.8%) and the presence of PAEN513F and PAEN862F signature sequences suggest that it is affiliated to the genus Paenibacillus. The G+C content of the genomic DNA was 53.9 mol%. On the basis of its phenotypic characteristics and phylogenetic distinctiveness, strain Gsoil 1411T is suggested to represent a novel species within the genus Paenibacillus, for which the name Paenibacillus panacisoli sp. nov. is proposed. The type strain is Gsoil 1411T (=KCTC 13020T=LMG 23405T).