The GaKAN2, a KANADI transcription factor, modulates stem trichomes in Gossypium arboreum.

KEY MESSAGE: GaKAN2, a member of the KANADI family, was found to be widely expressed in the cotton tissues and regulates trichome development through complex pathways. Cotton trichomes are believed to be the defense barrier against insect pests. Cotton fiber and trichomes are single-cell epidermal extensions with shared regulatory mechanisms. Despite several studies underlying mechanism of trichome development remains elusive. The KANADI is one of the key transcription factors (TFs) family, regulating Arabidopsis trichomes growth. However, the function of KANADI genes in cotton remains unknown. In the current study genome-wide scanning, transcriptomic analysis, gene silencing, subcellular localization, and yeast two-hybrid techniques were employed to decipher the function of KANADI TFs family genes in cotton crop. A total of 7 GaKAN genes were found in the Gossypium arboreum. Transcriptomic data revealed that these genes were significantly expressed in stem and root. Moreover, GaKAN2 was widely expressed in other tissues also. Subsequently, we selected GaKAN2 to validate the function of KANADI genes. Silencing of GaKAN2 resulted in a 24.99% decrease in single-cell trichomes and an 11.33% reduction in internodal distance, indicating its potential role in regulating trichomes and plant growth. RNA-Seq analysis elucidated that GaSuS and GaERS were the downstream genes of GaKAN2. The transcriptional activation and similarity in silencing phenotype between GaKAN2 and GaERS suggested that GaKAN2 regulates trichomes development through GaERS. Moreover, KEGG analysis revealed that a significant number of genes were enriched in the biosynthesis of secondary metabolites and plant hormone signal transduction pathways, thereby suggesting that GaKAN2 regulates the stem trichomes and plant growth. The GFP subcellular localization and yeast transcriptional activation analysis elucidated that GaKAN2 was located in the nucleus and capable of regulating the transcription of downstream genes. This study elucidated the function and characteristics of the KANADI gene family in cotton, providing a fundamental basis for further research on GaKAN2 gene in cotton plant trichomes and plant developmental processes.

Glutamatergic neurons in the paraventricular hypothalamic nucleus regulate isoflurane anesthesia in mice.

The glutamatergic-mediated excitatory system in the brain is vital for the regulation of sleep-wake and general anesthesia. Specifically, the paraventricular hypothalamic nucleus (PVH), which contains mainly glutamatergic neurons, has been shown to play a critical role in sleep-wake. Here, we sought to explore whether the PVH glutamatergic neurons have an important effect on the process of general anesthesia. We used c-fos staining and in vivo calcium signal recording to observe the activity changes of the PVH glutamatergic neurons during isoflurane anesthesia and found that both c-fos expression in the PVH and the calcium activity of PVH glutamatergic neurons decreased in isoflurane anesthesia and significantly increased during the recovery process. Chemogenetic activation of PVH glutamatergic neurons prolonged induction time and shortened emergence time from anesthesia by decreasing the depth of anesthesia. Using chemogenetic inhibition of PVH glutamatergic neurons under isoflurane anesthesia, we found that inhibition of PVH glutamatergic neurons facilitated the induction process and delayed the emergence accompanied by deepening the depth of anesthesia. Together, these results identify a crucial role for PVH glutamatergic neurons in modulating isoflurane anesthesia.

Epidemiology of congenital polydactyly and syndactyly in Hunan Province, China.

OBJECTIVE: To describe the prevalence and epidemiology of congenital polydactyly and syndactyly in Hunan Province, China, 2016-2020. METHODS: Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2016-2020. Prevalence of birth defects (polydactyly or syndactyly) is the number of cases per 1000 births (unit: ‰). Prevalence and 95% confidence intervals (CI) were calculated by the log-binomial method. Chi-square trend tests (χ2trend) were used to determine trends in prevalence by year. Crude odds ratios (ORs) were calculated to examine the association of each demographic characteristic with polydactyly and syndactyly. RESULTS: Our study included 847,755 births, and 14,459 birth defects were identified, including 1,888 polydactyly and 626 syndactyly cases, accounting for 13.06% and 4.33% of birth defects, respectively. The prevalences of total birth defects, polydactyly, and syndactyly were 17.06‰ (95%CI: 16.78-17.33), 2.23‰ (95%CI: 2.13-2.33), and 0.74‰ (95%CI: 0.68-0.80), respectively. Most polydactyly (96.77%) and syndactyly (95.69%) were diagnosed postnatally (within 7 days). From 2016 to 2020, the prevalences of polydactyly were 1.94‰, 2.07‰, 2.20‰, 2.54‰, and 2.48‰, respectively, showing an upward trend (χ2trend = 19.48, P < 0.01); The prevalences of syndactyly were 0.62‰, 0.66‰, 0.77‰, 0.81‰, and 0.89‰, respectively, showing an upward trend (χ2trend = 10.81, P = 0.03). Hand polydactyly (2.26‰ vs. 1.33‰, OR = 1.69, 95%CI: 1.52-1.87) and hand syndactyly (0.43‰ vs. 0.28‰, OR = 1.42, 95%CI: 1.14-1.76) were more common in males than females. Polydactyly (2.67‰ vs. 1.93‰, OR = 1.38, 95%CI: 1.26-1.51) and syndactyly (0.91‰ vs. 0.62‰, OR = 1.47, 95%CI: 1.26-1.72) were more common in urban areas than in rural areas. Compared to maternal age 25-29, hand polydactyly was more common in maternal age < 20 (2.48‰ vs. 1.74‰, OR = 1.43, 95%CI: 1.01-2.02) or ≥ 35 (2.25‰ vs. 1.74‰, OR = 1.30, 95%CI: 1.12-1.50). CONCLUSION: In summary, we have described the prevalence and epidemiology of polydactyly and syndactyly from hospital-based surveillance in Hunan Province, China, 2016-2020. Our findings make some original contributions to the field, which may be valuable for future research.

Strong interlayer coupling in p-Te/n-CdSe van der Waals heterojunction for self-powered photodetectors with fast speed and high responsivity.

Self-driven photodetectors, which can detect optical signals without external voltage bias, are highly attractive in the field of low-power wearable electronics and internet of things. However, currently reported self-driven photodetectors based on van der Waals heterojunctions (vdWHs) are generally limited by low responsivity due to poor light absorption and insufficient photogain. Here, we report p-Te/n-CdSe vdWHs utilizing non-layered CdSe nanobelts as efficient light absorption layer and high mobility Te as ultrafast hole transporting layer. Benefiting from strong interlayer coupling, the Te/CdSe vdWHs exhibit stable and excellent self-powered characteristics, including ultrahigh responsivity of 0.94 A W-1, remarkable detectivity of 8.36 × 1012 Jones at optical power density of 1.18 mW cm-2 under illumination of 405 nm laser, fast response speed of 24 µs, large light on/off ratio exceeding 105, as well as broadband photoresponse (405-1064 nm), which surpass most of the reported vdWHs photodetectors. In addition, the devices display superior photovoltaic characteristics under 532 nm illumination, such as large Voc of 0.55 V, and ultrahigh Isc of 2.73 µA. These results demonstrate the construction of 2D/non-layered semiconductor vdWHs with strong interlayer coupling is a promising strategy for high-performance and low-power consumption devices.

Perinatal deaths from birth defects in Hunan Province, China, 2010-2020.

OBJECTIVE: To describe the perinatal mortality rate (PMR) of birth defects and to define the relationship between birth defects (including a broad range of specific defects) and a broad range of factors. METHODS: Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2010-2020. The prevalence rate (PR) of birth defects is the number of birth defects per 1000 fetuses (births and deaths at 28 weeks of gestation and beyond). PMR is the number of perinatal deaths per 100 fetuses. PR and PMR with 95% confidence intervals (CI) were calculated using the log-binomial method. Chi-square trend tests (χ2trend) were used to determine trends in PR and PMR by year, maternal age, income, education level, parity, and gestational age of termination. Crude odds ratios (ORs) were calculated to examine the association of each maternal characteristic with perinatal deaths attributable to birth defects. RESULTS: Our study included 1,619,376 fetuses, a total of 30,596 birth defects, and 18,212 perinatal deaths (including 16,561 stillbirths and 1651 early neonatal deaths) were identified. The PR of birth defects was 18.89‰ (95%CI: 18.68-19.11), and the total PMR was 1.12%(95%CI: 1.11-1.14). Birth defects accounted for 42.0% (7657 cases) of perinatal deaths, and the PMR of birth defects was 25.03%. From 2010 to 2020, the PMR of birth defects decreased from 37.03% to 2010 to 21.00% in 2020, showing a downward trend (χ2trend = 373.65, P < 0.01). Congenital heart defects caused the most perinatal deaths (2264 cases); the PMR was 23.15%. PMR is highest for encephalocele (86.79%). Birth defects accounted for 45.01% (7454 cases) of stillbirths, and 96.16% (7168 cases) were selective termination of pregnancy. Perinatal deaths attributable to birth defects were more common in rural than urban areas (31.65% vs. 18.60%, OR = 2.03, 95% CI: 1.92-2.14) and in females than males (27.92% vs. 22.68%, OR = 1.32, 95% CI: 1.25-1.39). PMR of birth defects showed downward trends with rising maternal age (χ2trend = 200.86, P < 0.01), income (χ2trend = 54.39, P < 0.01), maternal education level (χ2trend = 405.66, P < 0.01), parity (χ2trend = 85.11, P < 0.01) and gestational age of termination (χ2trend = 15297.28, P < 0.01). CONCLUSION: In summary, birth defects are an important cause of perinatal deaths. Rural areas, female fetuses, mothers with low maternal age, low income, low education level, low parity, and low gestational age of termination were risk factors for perinatal deaths attributable to birth defects. Future studies should examine the mechanisms. Our study is helpful for intervention programs to reduce the PMR of birth defects.

Optical design of a reflective double-grating spectrometer to detect one branch in the pure rotational Raman spectrum of N2.

This paper presents the optical design of a high-resolution double-grating spectrometer for extracting the multiple lines in the Stokes or anti-Stokes branch of the pure rotational Raman spectra of nitrogen. The spectrometer is composed of collimating and focusing mirrors, two reflective gratings, and a linear detector. The structural parameters were calculated using geometric configuration, dispersion, and aberrational theory, and conditions for first-order correction of keystone distortion with divergent grating illumination were derived. Based on this method, we simulated a spectrometer with a 16-channel linear array photomultiplier tube, resulting in uniformly distributed single-branch lines on each detector channel. The resolution reached 0.225 nm per channel, and the keystone distortion was less than 0.7%. The spectrometer avoids the interference of elastic signals by not detecting them, enabling the extraction of atmospheric temperature profiles via separated single-branch lines with high precision. Our design provides a promising solution to extract atmospheric temperature profiles for pure rotational Raman lidar.

Simulation and misalignment analysis of the gain ratio of a polarization Mie Raman lidar.

The gain ratio is a critical parameter in a polarization Mie lidar. Calibrating the gain ratio is essential in aerosol classification studies. We developed a ray-tracing-based simulation method to investigate the impact of mounting errors on the gain ratio. In this method, a computational model for each element of the lidar was built, and Zemax was used to simulate the lidar receiver to obtain the optical gain ratio by theoretical calculations. This method can analyze the influence of each element's mounting errors and offer a theoretical foundation for the machining and mounting accuracy of the lidar design. The correctness of the model was verified by applying it to a single-wavelength polarization Mie Raman lidar.

Simulation and misalignment analysis of the gain ratio of a polarization Mie Raman lidar: publisher's note.

This publisher's note serves to correct an error in Appl. Opt.61, 2881 (2022)APOPAI0003-693510.1364/AO.453852.

Differentiation in the genetic basis of stem trichome development between cultivated tetraploid cotton species.

BACKGROUND: Cotton stem trichomes and seed fibers are each single celled structures formed by protrusions of epidermal cells, and were found sharing the overlapping molecular mechanism. Compared with fibers, cotton stem trichomes are more easily observed, but the molecular mechanisms underlying their development are still poorly understood. RESULTS: In this study, Gossypium hirsutum (Gh) and G. barbadense (Gb) were found to differ greatly in percentages of varieties/accessions with glabrous stems and in trichome density, length, and number per trichopore. Gh varieties normally had long singular and clustered trichomes, while Gb varieties had short clustered trichomes. Genetic mapping using five F2 populations from crosses between glabrous varieties and those with different types of stem trichomes revealed that much variation among stem trichome phenotypes could be accounted for by different combinations of genes/alleles on Chr. 06 and Chr. 24. The twenty- six F1 generations from crosses between varieties with different types of trichomes had varied phenotypes, further suggesting that the trichomes of tetraploid cotton were controlled by different genes/alleles. Compared to modern varieties, a greater proportion of Gh wild accessions were glabrous or had shorter and denser trichomes; whereas a smaller proportion of Gb primitive accessions had glabrous stems. A close correlation between fuzz fiber number and stem trichome density was observed in both Gh and Gb primitive accessions and modern varieties. CONCLUSION: Based on these findings, we hypothesize that stem trichomes evolved in parallel with seed fibers during the domestication of cultivated tetraploid cotton. In addition, the current results illustrated that stem trichome can be used as a morphological index of fiber quality in cotton conventional breeding.

A Modified Actin (Gly65Val Substitution) Expressed in Cotton Disrupts Polymerization of Actin Filaments Leading to the Phenotype of Ligon Lintless-1 (Li1) Mutant.

Dynamic remodeling of the actin cytoskeleton plays a central role in the elongation of cotton fibers, which are the most important natural fibers in the global textile industry. Here, a high-resolution mapping approach combined with comparative sequencing and a transgenic method revealed that a G65V substitution in the cotton actin Gh_D04G0865 (GhACT17D in the wild-type) is responsible for the Gossypium hirsutum Ligon lintless-1 (Li1) mutant (GhACT17DM). In the mutant GhACT17DM from Li1 plant, Gly65 is substituted with valine on the lip of the nucleotide-binding domain of GhACT17D, which probably affects the polymerization of F-actin. Over-expression of GhACT17DM, but not GhACT17D, driven by either a CaMV35 promoter or a fiber-specific promoter in cotton produced a Li1-like phenotype. Compared with the wild-type control, actin filaments in Li1 fibers showed higher growth and shrinkage rates, decreased filament skewness and parallelness, and increased filament density. Taken together, our results indicate that the incorporation of GhACT17DM during actin polymerization disrupts the establishment and dynamics of the actin cytoskeleton, resulting in defective fiber elongation and the overall dwarf and twisted phenotype of the Li1 mutant.

GaHD1, a candidate gene for the Gossypium arboreum SMA-4 mutant, promotes trichome and fiber initiation by cellular H2O2 and Ca2+ signals.

Cotton fibers are initiated from the epidermal cells of the ovule before or on the day of anthesis. Gossypium arboreum SMA-4 mutant contains recessive mutation (sma-4(ha)) and has the phenotypes of fibreless seeds and glabrous stems. In this study, fine mapping and alternative splicing analysis indicated a nucleotide substitution (AG → AC) at splicing site in a homeodomain-leucine zipper IV family gene (GaHD1) might cause gene A3S (Alternative 3' splicing) mistake, suggested that GaHD1 was the candidate gene of sma-4(ha). Many genes related to the fiber initiation are identified to be differentially expressed in the mutant which could result in the blocked fiber initiation signals such as H2O2, or Ca in the mutant. Further comparative physiological analysis of H2O2 production and Ca2+ flux in the SMA-4 and wide type cotton confirmed that H2O2 and Ca were important fiber initiation signals and regulated by GaHD1. The in vitro ovule culture of the mutant with hormones recovered the fibered phenotype coupled with the restoration of these signals. Overexpressing of GaHD1 in Arabidopsis increased trichome densities on the sepal, leaf, and stem tissues while transient silencing of the GaHD1 gene in G. arboreum reduced the trichome densities. These phenotypes indicated that GaHD1 is the candidate gene of SMA-4 with a crucial role in acting upstream molecular switch of signal transductions for cotton trichome and fiber initiations.

Preferential insertion of a Ty1 LTR-retrotransposon into the A sub-genome's HD1 gene significantly correlated with the reduction in stem trichomes of tetraploid cotton.

Stem trichomes and seed fibers originate from epidermal cells and partially share a regulatory pathway at the molecular level. In Gossypium barbadense, two insertions of a Ty1 long-terminal repeat-retrotransposon [transposable element TE1 and TE2] in a homeodomain-leucine zipper gene (HD1) result in glabrous stems. The primers used to identify the TE insertions in G. barbadense were applied to screen for the same events in 81 modern G. hirsutum varieties and 31 wild races. Three wild races were found carrying the same TEs as G. barbadense. However, the TE insertions in two of these wild races occurred at different sites (4th exon), therefore, named TE3, while the TE in the other wild race occurred at the same site as TE2. An RNA sequencing and qRT-PCR analysis indicated that the loss of HD1 function was caused by the TE insertion. Genetic mapping revealed a strong association between glabrous stems and TE3 insertions, confirming that HD1 is a critical gene for stem trichome initiation in G. hirsutum, as in G. barbadense. Using the long-terminal repeat sequence as a query to search against the Texas Marker-1 reference genome sequence, we found that the TE occurred after tetraploid cotton formation and evolved at different rates in G. hirsutum and G. barbadense. Interestingly, at least three independent insertion events of the same retrotransposon occurred preferentially in the A sub-genome's HD1 gene, but not in the D sub-genome of G. hirsutum or G. barbadense, suggesting that an unknown TE insertion mechanism and resultant gene function changes may have hastened cotton speciation.

Ultra-sensitive solution-processed broadband photodetectors based on vertical field-effect transistor.

In the past few decades, great attention has been paid to the development of IV-VI semiconductor colloidal quantum dots, such as PbSe, PbS and PbSSe, in infrared (IR) photodetectors due to their high photosensitivity, solution-processing and low cost fabrication. IR photodetectors based on field-effect transistors (FETs) showed high detectivity since the transconductance can magnify the drain-source current under certain applied gate voltages. However, traditional lateral FETs usually suffer from low photosensitivity and slow responsivity, which restricts their widespread commercial applications. In this work, therefore, novel vertical FET (VFET) based photodetectors are presented, in which the active layer is sandwiched between porous source electrode and planar drain electrode, resulting to ultrashort channel length. In this way, enhanced photoresponsivity and specific detectivity of 291 A W-1 and 1.84 × 1014 Jones, respectively, can be obtained at low drain-source voltage (V DS) of -1 V and gate voltage (V g) of -2 V under 100 µW cm-2 illumination intensity, which was better than that of the traditional lateral FET based photodetectors. Therefore, it is promising to fabricate broadband photodetectors with high performance and good stability by this easy approach.

A one-step method to synthesize CH3NH3PbI3:MoS2 nanohybrids for high-performance solution-processed photodetectors in the visible region.

A facile method to synthesize a CH3NH3PbI3: MoS2 nanohybrid for high-performance solution-processed photodetectors is presented. The interfacial charge carriers transfer due to the existence of heterojunctions between the 2D MoS2 nanosheet and perovskite cuboids are utilized to enhance the device performance. The dark current of the photodiode Au/CH3NH3PbI3: MoS2/Au was suppressed and its photocurrent was enhanced when compared to a pristine perovskite nanocrystal device Au/CH3NH3PbI3/Au. The lowest dark current of 0.34 × 10-9 A was observed from the photodiode Au/CH3NH3PbI3: MoS2/Au and the photoresponsivity and photosensitivity increased from 312 mA W-1 to 696 mA W-1 and from 9.02 to 87.47, respectively, showing an enhancement of 123.1% and 869.7%. Also, the rising time and falling time were reduced from 73 ms to 50 ms and 60 ms to 16 ms, respectively, when compared to those for the pristine perovskite nanocrystal-based photodiode Au/CH3NH3PbI3/Au. Therefore, this method provides a simple and effective approach to synthesize 2D nanosheet blended organic-inorganic nanohybrids for application in optoelectronic devices.

High-performance solution-processed colloidal quantum dots-based tandem broadband photodetectors with dielectric interlayer.

Recently, great attention has been paid to IV-VI colloidal quantum dots (CQDs) for their high photosensitivity, solution processability and low cost. Also, metal halide perovskites are very promising materials to realize the high-performance solution-processed visible-light photodetectors due to their cost-effective manufacturing, tunable absorption and photoluminescence in whole visible spectrum. In this paper, we present solution-processed CQDs-based tandem broadband photodetectors with low dark-current and high-sensitivity by inserting dielectric Polymethyl methacrylate (PMMA) interlayer between two sub-detectors. Our experimental data showed that the tandem broadband photodetector ITO/PEDOT:PSS/CsPbBr3:PbS0.4Se0.6/ZnO/PVK/CsPbBr3:PbS0.4Se0.6/ZnO/Au showed a maximum specific detectivity of 6.8 × 1013 Jones with a responsivity of 27 A W-1 under 57.8 µW cm-2 980 nm illumination. The device performance can be further enhanced by inserting a 50 nm dielectric PMMA layer between the two sub-photodetectors. As the result, the tandem photodetector ITO/PEDOT:PSS/CsPbBr3:PbS0.4Se0.6/ZnO/PMMA(50 nm)/PVK/CsPbBr3:PbS0.4Se0.6/ZnO/Au exhibits a maximum specific detectivity of 1.32 × 1014 Jones with a responsivity of 27.72 A W-1 under 57.8 µW cm-2 of 980 nm laser. Further, the physical mechanisms for the enhanced performance are discussed in detail.

The impacts of brewing in glass tumblers and thermos vacuum mugs on the aromas of green tea (Camellia sinensis).

This study investigated the effect of brewing apparatus on the aromatic feature of tea infusion. Huangshan Maofeng tea infusion was brewed under glass tumblers (GT) or thermos vacuum mugs (TVM) for up to 180 min. Tea infusion sensory attributes were evaluated using quantitative descriptive analysis and the composition of volatiles were analyzed using headspace solid phase microextraction coupled with gas chromatography-mass spectrometry. Results showed that GT tea infusion at each brewing duration possessed stronger 'Pure', 'Fresh' and 'Grassy' attributes than TVM tea infusion, whereas TVM tea infusion showed a higher intensity on 'Steamed' aroma. A total of 74 volatiles were detected in tea infusion, and aldehydes and alcohols appeared to be the major volatiles. Total aldehydes concentration percentage decreased in tea infusion with brewing process, whereas an increase on total alcohol percentage was found. Principal component analysis indicated that brewing duration and apparatus played vital roles in altering the volatile composition in tea infusion, whereas orthogonal partial least squares discriminant analysis (OPLS-DA) revealed that GT tea infusion samples were separated from TVM tea infusion samples. OPLS-DA also screened 20 volatiles that significantly contributed to the differentiation of GT and TVM tea infusion.

Recommended storage temperature for green tea based on sensory quality.

This study aimed to evaluate the effect of storage temperature on the alteration of the sensory quality of tea. Huangshan Maofeng tea was stored at - 80 °C, - 20 °C, 4 °C, or room temperature for up to 150 days. The physicochemical parameters, taste-related components, appearance color, volatile compounds and sensory quality of tea were analyzed and compared. Results showed that storing tea at - 80 °C and - 20 °C effectively preserved the physicochemical parameters, taste-related compounds and appearance color in tea. Multivariate statistical analysis (PCA and OPLS-DA) indicated that tea stored at - 80 °C exhibited a similar volatiles composition as fresh tea based on gas chromatography-mass spectrometry, whereas the composition of volatiles was significantly altered in tea stored at 4 °C after 100 days of storage. Sensory evaluation illustrated that tea stored at - 80 °C and - 20 °C remained the freshness regarding leaves appearance and tea infusion color, taste and aroma, whereas an obvious decrease on the tea freshness was found in tea stored at 4 °C and room temperature. These findings indicated that storage temperature played a vital role in altering the aromatic and sensory quality of Huangshan Maofeng tea and the recommended tea storage temperature was - 80 °C or - 20 °C.

Enhanced performance of solution-processed broadband photodiodes by epitaxially blending MAPbBr3 quantum dots and ternary PbSxSe1-x quantum dots as the active layer.

Organic-inorganic hybrid photodetectors attract more and more interest, since they can combine the advantages of both organic and inorganic materials into one device, and broadband photodetectors are widely used in many scientific and industrial fields. In this work, we demonstrate the enhanced-performance solution-processed broadband photodiodes by epitaxially blending organo-lead halide perovskite (MAPbBr3) colloidal quantum dots (CQDs) with ternary PbSxSe1-x CQDs as the active layer. As a result, the interfacial features of the hetero-epitaxial nanocomposite MAPbBr3:PbSxSe1-x enables the design and perception of functionalities that are not available for the single-phase constituents or layered devices. By combining the high electrical transport properties of MAPbBr3 QDs with the highly radiative efficiency of PbS0.4Se0.6 QDs, the photodiodes ITO/ZnO/PbS0.4Se0.6:MAPbBr3/Au exhibit a maximum photoresponsivity and specific detectivity of 21.48 A W-1 and 3.59 × 1013 Jones, 22.16 A W-1 and 3.70 × 1013 Jones at room temperature under 49.8 µW cm-2 532 nm laser and 62 µW cm-2 980 nm laser, respectively. This is higher than that of the layered photodiodes ITO/ZnO/PbS0.4Se0.6/MAPbBr3/Au, pure perovskite (MAPbBr3) (or PbS0.4Se0.6) QD-based photodiodes reported previously, and it is also better than the traditional inorganic semiconductor-based photodetectors. Our experimental results indicate that epitaxially-aligned nanocomposites (MAPbBr3:PbSxSe1-x) exhibit remarkable optoelectronic properties that are traceable to their atomic-scale crystalline coherence, and one can utilize the excellent photocarrier diffusion from PbSxSe1-x into the perovskite to enhance the device performance from the UV-visible to infrared region.

Mass Measurement of Single Intact Nanoparticles in a Cylindrical Ion Trap.

Accurate nanoparticle mass characterization is a challenging task, especially at a single particle level. To solve this problem, a strategy for the mass measurement of single intact nanoparticle was proposed. A microscopy-based ion trap mass spectrometer was built up. To improve the detection sensitivity, a cylindrical ion trap with transparent conductive end-caps was used to increase the transmission of scattered light, and a vacuum ultraviolet lamp was used to increase the charge state of the isolated nanoparticle. By detecting the scattered light of the isolated nanoparticle, a series of secular frequencies were obtained, from which the corresponding mass-to-charge ratio of the nanoparticle was calculated. Finally, a Labview program was used to help deduce the charge state and absolute mass of the individual nanoparticle. Masses of gold nanoparticles with different sizes were accurately examined, which are (5.08 ± 0.44) × 10(7) Da for 20 nm, (3.55 ± 0.34) × 10(8) Da for 40 nm, and (1.22 ± 0.14) × 10(9) Da for 60 nm, respectively. The mass of MOFs with irregular shapes was also determined, which is (6.48 ± 1.08) × 10(9) Da. This method can provide the mass information on nanomaterials, thus opens up new possibility of characterizing nanoparticles at the single particle level.

Genome-wide investigation and transcriptome analysis of the WRKY gene family in Gossypium.

WRKY transcription factors play important roles in various stress responses in diverse plant species. In cotton, this family has not been well studied, especially in relation to fiber development. Here, the genomes and transcriptomes of Gossypium raimondii and Gossypium arboreum were investigated to identify fiber development related WRKY genes. This represents the first comprehensive comparative study of WRKY transcription factors in both diploid A and D cotton species. In total, 112 G. raimondii and 109 G. arboreum WRKY genes were identified. No significant gene structure or domain alterations were detected between the two species, but many SNPs distributed unequally in exon and intron regions. Physical mapping revealed that the WRKY genes in G. arboreum were not located in the corresponding chromosomes of G. raimondii, suggesting great chromosome rearrangement in the diploid cotton genomes. The cotton WRKY genes, especially subgroups I and II, have expanded through multiple whole genome duplications and tandem duplications compared with other plant species. Sequence comparison showed many functionally divergent sites between WRKY subgroups, while the genes within each group are under strong purifying selection. Transcriptome analysis suggested that many WRKY genes participate in specific fiber development processes such as fiber initiation, elongation and maturation with different expression patterns between species. Complex WRKY gene expression such as differential Dt and At allelic gene expression in G. hirsutum and alternative splicing events were also observed in both diploid and tetraploid cottons during fiber development process. In conclusion, this study provides important information on the evolution and function of WRKY gene family in cotton species.