Organelle Genomes of Epipogium roseum Provide Insight into the Evolution of Mycoheterotrophic Orchids.

Epipogium roseum, commonly known as one of the ghost orchids due to its rarity and almost transparent color, is a non-photosynthetic and fully mycoheterotrophic plant. Given its special nutritional strategies and evolutionary significance, the mitogenome was first characterized, and three plastomes sampled from Asia were assembled. The plastomes were found to be the smallest among Orchidaceae, with lengths ranging from 18,339 to 19,047 bp, and exhibited high sequence variety. For the mitogenome, a total of 414,552 bp in length, comprising 26 circular chromosomes, were identified. A total of 54 genes, including 38 protein-coding genes, 13 tRNA genes, and 3 rRNA genes, were annotated. Multiple repeat sequences spanning a length of 203,423 bp (45.47%) were discovered. Intriguingly, six plastid regions via intracellular gene transfer and four plastid regions via horizontal gene transfer to the mitogenome were observed. The phylogenomics, incorporating 90 plastomes and 56 mitogenomes, consistently revealed the sister relationship of Epipogium and Gastrodia, with a bootstrap percentage of 100%. These findings shed light on the organelle evolution of Orchidaceae and non-photosynthetic plants.

The phosphoproteomic and interactomic landscape of qGL3/OsPPKL1-mediated brassinosteroid signaling in rice.

Oryza sativa L. (rice) is one of the most important crops in the world, and grain size is a major component determining rice yield. Recent studies have identified a number of grain size regulators, which are involved in phytohormone signaling, G protein signaling, the mitogen-activated protein kinase signaling pathway, the ubiquitin-proteasome pathway or transcriptional regulation. In a previous study, we cloned qGL3/OsPPKL1 encoding a rice protein phosphatase that negatively modulates brassinosteroid (BR) signaling and grain length. Here, to further explore the qGL3-mediated BR signaling network, we performed phosphoproteomic screenings using two pairs of rice materials: the indica rice cultivar 9311 and its near-isogenic line NILqgl3 and the japonica rice cultivar Dongjin and its qGL3 knockout mutant m-qgl3. Together with qGL3-interacting proteins, we constructed the qGL3-mediated network, which reveals the relationships between BR signaling and other critical signaling pathways. Transgenic plants of these network components showed BR-related alterations in plant architecture. From this network, we validated a qGL3-interacting protein, O. sativa VERNALIZATION INSENSITIVE 3-LIKE 1 (OsVIL1), and demonstrated that qGL3 dephosphorylates OsVIL1 to modulate BR signaling. The qGL3-dependent network uncovered in this study increases our understanding of BR signaling and provides a profound foundation for addressing how BR modulates plant architecture in rice.

Comparative and phylogenetic analysis of Chiloschista (Orchidaceae) species and DNA barcoding investigation based on plastid genomes.

BACKGROUND: Chiloschista (Orchidaceae, Aeridinae) is an epiphytic leafless orchid that is mainly distributed in tropical or subtropical forest canopies. This rare and threatened orchid lacks molecular resources for phylogenetic and barcoding analysis. Therefore, we sequenced and assembled seven complete plastomes of Chiloschista to analyse the plastome characteristics and phylogenetic relationships and conduct a barcoding investigation. RESULTS: We are the first to publish seven Chiloschista plastomes, which possessed the typical quadripartite structure and ranged from 143,233 bp to 145,463 bp in size. The plastomes all contained 120 genes, consisting of 74 protein-coding genes, 38 tRNA genes and eight rRNA genes. The ndh genes were pseudogenes or lost in the genus, and the genes petG and psbF were under positive selection. The seven Chiloschista plastomes displayed stable plastome structures with no large inversions or rearrangements. A total of 14 small inversions (SIs) were identified in the seven Chiloschista plastomes but were all similar within the genus. Six noncoding mutational hotspots (trnNGUU-rpl32 > rpoB-trnCGCA > psbK-psbI > psaC-rps15 > trnEUUC-trnTGGU > accD-psaI) and five coding sequences (ycf1 > rps15 > matK > psbK > ccsA) were selected as potential barcodes based on nucleotide diversity and species discrimination analysis, which suggested that the potential barcode ycf1 was most suitable for species discrimination. A total of 47-56 SSRs and 11-14 long repeats (> 20 bp) were identified in Chiloschista plastomes, and they were mostly located in the large single copy intergenic region. Phylogenetic analysis indicated that Chiloschista was monophyletic. It was clustered with Phalaenopsis and formed the basic clade of the subtribe Aeridinae with a moderate support value. The results also showed that seven Chiloschista species were divided into three major clades with full support. CONCLUSION: This study was the first to analyse the plastome characteristics of the genus Chiloschista in Orchidaceae, and the results showed that Chiloschista plastomes have conserved plastome structures. Based on the plastome hotspots of nucleotide diversity, several genes and noncoding regions are suitable for phylogenetic and population studies. Chiloschista may provide an ideal system to investigate the dynamics of plastome evolution and DNA barcoding investigation for orchid studies.

The origin and evolution of emerged swine acute diarrhea syndrome coronavirus with zoonotic potential.

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a newly discovered alphacoronavirus with zoonotic potential that causes diarrhea and vomiting mainly in piglets. Having emerged suddenly in 2017, the prevailing opinion is that the virus originated from HKU2, an alphacoronavirus whose primary host is bats, and at some unknown point achieved interspecies transmission via some intermediate. Here, we further explore the evolutionary history and possible cross-species transmission event for SADS-CoV. Coevolutionary analysis demonstrated that HKU2 may have achieved host switch via SADS-related (SADSr)-CoV, which was isolated from the genus Rhinolophus in 2017. SADS-CoV, HKU2, and SADSr-CoV share similar codon usage patterns and showed a lower tendency to use CpG, which may reflect a method of immune escape. The analyses of virus-host coevolution and recombination support SADSr-CoV is the direct source of SADS-CoV that may have undergone recombination events during its formation. Structure-based spike glycoprotein variance analysis revealed a more nuanced evolutionary pathway to receptor recognition for host switch. We did not find a possible positive selection site, and the dN/dS of the S gene was only 0.29, which indicates that the current SADS-CoV is slowly evolving. These results provide new insights that may help predict future cross-species transmission, and possibly surveil future zoonotic outbreaks and associated public health emergencies.

Dual camera snapshot high-resolution-hyperspectral imaging system with parallel joint optimization via physics-informed learning.

The hardware architecture of the coded aperture snapshot spectral imaging (CASSI) system is based on a coded mask design, resulting in a poor spatial resolution of the system. Therefore, we consider the use of a physical model of optical imaging and a jointly optimized mathematical model to design a self-supervised framework to solve the high-resolution-hyperspectral imaging problem. In this paper, we design a parallel joint optimization architecture based on a two-camera system. This framework combines the physical model of optical system and a joint optimization mathematical model, which takes full advantage of the spatial detail information provided by the color camera. The system has a strong online self-learning capability for high-resolution-hyperspectral image reconstruction, and gets rid of the dependence of supervised learning neural network methods on training data sets.

Comparison of Single-operator Laser-assisted Ultrasound-guided Radial Arterial Cannulation in Young Children with Traditional Ultrasound Guidance: A Randomized Clinical Trial.

BACKGROUND: Radial artery cannulation in young children is challenging. A single-operator laser-assisted ultrasound-guidance system was invented to project the path of the target artery on the skin surface. The hypothesis was that this system would improve the first-attempt success rate of radial arterial cannulation in young pediatric patients relative to traditional ultrasound guidance. METHODS: This single-center, prospective, parallel-group, randomized controlled study enrolled pediatric patients (n = 80, age less than 2 yr) requiring radial artery cannulation during general anesthesia. The participants were randomized into the traditional ultrasound-guidance group or the single-operator laser-assisted ultrasound-guidance group. After inducing general anesthesia, ultrasound-guided radial artery cannulation was performed by two experienced operators. The primary outcome was the first-attempt success rate. The secondary outcomes included the procedure time to success within the first attempt, midmost rate of first attempt, first needle-tip position, and average number of adjustments. RESULTS: In total, 80 children were included in the analysis. The first-attempt success rate in the single-operator laser-assisted ultrasound-guidance group (36 of 40 [90%]) was significantly greater than that in the traditional ultrasound-guidance group (28 of 40 [70%]; absolute difference, 20% [95% CI, 2.3% to 36.6%]; P = 0.025). The median procedure time to success within the first attempt was shorter in the single-operator laser-assisted ultrasound-guidance group compared with the traditional ultrasound-guidance group (31 s [27, 36 s] vs. 46 s [39, 52 s]; P < 0.001). The incidence of hematoma in the single-operator laser-assisted ultrasound-guidance group (1 of 40, 3%) was significantly lower than that in the traditional ultrasound-guidance group (11 of 40, 28%; P = 0.002). Regarding the initial needle-tip position after skin puncture, the median score (4 [3,4] vs. 2 [2,3]; P < 0.001); position 3, 4, or 5 (38 [95%] vs. 13 [33%]; P < 0.001); and position 4 or 5 (26 [65%] vs. 5 [13%]; P < 0.001) were all in favor of single-operator laser-assisted ultrasound guidance. CONCLUSIONS: Compared with traditional ultrasound guidance, the single-operator laser-assisted ultrasound-guided system is a useful add-on to the ultrasound dynamic needle-tip puncture technique. It improves the first-attempt success rate of radial artery cannulation in children younger than 2 yr by projecting the path of the artery on the skin and provides better procedural conditions (stable ultrasound probe).

Fully Integrated Line Array Angular Displacement Sensing Chip.

The angular displacement sensor is a digital angular displacement measurement device that integrates optics, mechanics, and electronics. It has important applications in communication, servo control, aerospace, and other fields. Although conventional angular displacement sensors can achieve extremely high measurement accuracy and resolution, they cannot be integrated because complex signal processing circuitry is required at the photoelectric receiver, which limits their suitability for robotics and automotive applications. The design of a fully integrated line array angular displacement-sensing chip is presented for the first time using a combination of pseudo-random and incremental code channel designs. Based on the charge redistribution principle, a fully differential 12-bit, 1 MSPS sampling rate successive approximation analog-to-digital converter (SAR ADC) is designed for quantization and subdivision of the incremental code channel output signal. The design is verified with a 0.35 µm CMOS process and the area of the overall system is 3.5 × 1.8 mm2. The fully integrated design of the detector array and readout circuit is realized for the angular displacement sensing.

Complete Chloroplast Genomes and Comparative Analyses of Three Paraphalaenopsis (Aeridinae, Orchidaceae) Species.

Paraphalaenopsis, a genus of perennial herbs from the family Orchidaceae, contains a number of ornamental species. However, there is no information on the chloroplast genomes of Paraphalaenopsis, which limits our studies of this genus. In this study, we reported the chloroplast genomes of three species of Paraphalaenopsis (P. labukensis, P. denevel, and P. laycockii 'Semi-alba') and performed comprehensive comparative analysis. These three chloroplast genomes showed a typical quadripartile structure. Their lengths ranged from 147,311 bp to 149,240 bp. Each genome contained 120 unique genes, including 74 protein-coding genes, 38 tRNA genes, and 8 rRNA genes. Comparative analysis revealed major differences in sequence divergence in the three chloroplast genomes. In addition, six hypervariable regions were identified (psbM-trnDGUC, psbB, ccsA, trnKUUU, trnSGCU-trnGUCC, rps16-trnQUUG) that can be used as DNA molecular markers. Phylogenetic relationships were determined using the chloroplast genomes of 28 species from 12 genera of Aeridinae. Results suggested that Paraphalaenopsis was a clade of Aeridinae that was sister to the Holcoglossum-Vanda clade, with 100% bootstrap support within Aeridinae. The findings of this study provided the foundation for future studies on the phylogenetic analysis of Aeridinae.

Characterization and Comparative Analysis of the Complete Plastomes of Five Epidendrum (Epidendreae, Orchidaceae) Species.

Epidendrum, one of the three largest genera of Orchidaceae, exhibits significant horticultural and ornamental value and serves as an important research model in conservation, ecology, and evolutionary biology. Given the ambiguous identification of germplasm and complex evolutionary relationships within the genus, the complete plastome of this genus (including five species) were firstly sequenced and assembled to explore their characterizations. The plastomes exhibited a typical quadripartite structure. The lengths of the plastomes ranged from 147,902 bp to 150,986 bp, with a GC content of 37.16% to 37.33%. Gene annotation revealed the presence of 78-82 protein-coding genes, 38 tRNAs, and 8 rRNAs. A total of 25-38 long repeats and 130-149 SSRs were detected. Analysis of relative synonymous codon usage (RSCU) indicated that leucine (Leu) was the most and cysteine (Cys) was the least. The consistent and robust phylogenetic relationships of Epidendrum and its closely related taxa were established using a total of 43 plastid genomes from the tribe Epidendreae. The genus Epidendrum was supported as a monophyletic group and as a sister to Cattleya. Meanwhile, four mutational hotspots (trnCGCA-petN, trnDGUC-trnYGUA, trnSGCU-trnGUCC, and rpl32-trnLUAG) were identified for further phylogenetic studies. Our analysis demonstrates the promising utility of plastomes in inferring the phylogenetic relationships of Epidendrum.

Characteristics and Comparative Analysis of Seven Complete Plastomes of Trichoglottis s.l. (Aeridinae, Orchidaceae).

Trichoglottis exhibits a range of rich variations in colors and shapes of flower and is a valuable ornamental orchid genus. The genus Trichoglottis has been expanded by the inclusion of Staurochilus, but this Trichoglottis sensu lato (s.l.) was recovered as a non-monophyletic genus based on molecular sequences from one or a few DNA regions. Here, we present phylogenomic data sets, incorporating complete plastome sequences from seven species (including five species sequenced in this study) of Trichoglottis s.l. (including two species formerly treated as Staurochilus), to compare plastome structure and to reconstruct the phylogenetic relationships of this genus. The seven plastomes possessed the typical quadripartite structure of angiosperms and ranged from 149,402 bp to 149,841 bp with a GC content of 36.6-36.7%. These plastomes contain 120 genes, which comprise 74 protein-coding genes, 38 tRNA genes, and 8 rRNA genes, all ndh genes were pseudogenized or lost. A total of 98 (T. philippinensis) to 134 (T. ionosma) SSRs and 33 (T. subviolacea) to 46 (T. ionosma) long repeats were detected. The consistent and robust phylogenetic relationships of Trichoglottis were established using a total of 25 plastid genomes from the Aeridinae subtribe. The genus Trichoglottis s.l. was strongly supported as a monophyletic group, and two species formerly treated as Staurochilus were revealed as successively basal lineages. In addition, five mutational hotspots (trnNGUU-rpl32, trnLUAA, trnSGCU-trnGUCC, rbcL-accD, and trnTGGU-psbD) were identified based on the ranking of PI values. Our research indicates that plastome data is a valuable source for molecular identification and evolutionary studies of Trichoglottis and its related genera.

Comparative Analysis of Plastomes in Elsholtzieae: Phylogenetic Relationships and Potential Molecular Markers.

The Elsholtzieae, comprising ca. 7 genera and 70 species, is a small tribe of Lamiaceae (mint family). Members of Elsholtzieae are of high medicinal, aromatic, culinary, and ornamentals value. Despite the rich diversity and value of Elsholtzieae, few molecular markers or plastomes are available for phylogenetics. In the present study, we employed high-throughput sequencing to assemble two Mosla plastomes, M. dianthera and M. scabra, for the first time, and compared with other plastomes of Elsholtzieae. The plastomes of Elsholtzieae exhibited a quadripartite structure, ranging in size from 148,288 bp to 152,602 bp. Excepting the absence of the pseudogene rps19 in Elsholtzia densa, the exhaustive tally revealed the presence of 132 genes (113 unique genes). Among these, 85 protein-coding genes (CDS), 37 tRNA genes, 8 rRNA genes, and 2 pseudogenes (rps19 and ycf1) were annotated. Comparative analyses showed that the plastomes of these species have minor variations at the gene level. Notably, the E. eriostchya plastid genome exhibited increased GC content regions in the LSC and SSC, resulting in an increased overall GC content of the entire plastid genome. The E. densa plastid genome displayed modified boundaries due to inverted repeat (IR) contraction. The sequences of CDS and intergenic regions (IGS) with elevated variability were identified as potential molecular markers for taxonomic inquiries within Elsholtzieae. Phylogenetic analysis indicated that four genera formed monophyletic entities, with Mosla and Perilla forming a sister clade. This clade was, in turn, sister to Collinsonia, collectively forming a sister group to Elsholtzia. Both CDS, and CDS + IGS could construct a phylogenetic tree with stronger support. These findings facilitate species identification and DNA barcoding investigations in Elsholtzieae and provide a foundation for further exploration and resource utilization within this tribe.

Plastid phylogenomic data yield new and robust insights into the phylogeny of Cleisostoma-Gastrochilus clades (Orchidaceae, Aeridinae).

The Cleisostoma-Gastrochilus clades are among the most speciose and diverse groups of Asian orchids and are a taxonomically problematic group. Phylogenetic relationships among the genera of these clades have remained unresolved with traditional sequences from one or a few markers. We present large-scale phylogenomic data sets, incorporating complete chloroplast genome sequences from 53 species (including 41 species sequenced in this study), to compare plastome structure and to resolve the phylogenetic relationships of these clades. The plastomes of Cleisostoma-Gastrochilus clades possessed the quadripartite structure and plastome genes of typical angiosperms with sizes ranging from 142 to 149 kb and encoding a set of 118-120 genes. Unusual structural features were detected in the plastome of Uncifera acuminata, including the presence of a large 17-kb inversion (19 genes) in the Large Single-Copy region and the loss of the rpl32 gene in Cleisostoma fuerstenbergianum. The pseudogenization of ndh genes was widespread in these clades. Phylogenomic analyses, including 68 plastid protein-coding genes, showed that these clades can be subdivided into three major groupings and six subgroupings: Vandopsis undulata, the Gastrochilus clade (including the Trichoglottis and Gastrochilus subclades) and the Cleisostoma clade (including the Vandopsis, Diploprora, Cleisostoma and Schoenorchis subclades). Two genera, Vandopsis and Cleisostoma, were not monophyletic. A new genus, Cymbilabia, was proposed to avoid non-monophyly of Vandopsis. Our results demonstrate the power of plastid phylogenomics to improve the phylogenetic relationships of intricate groups and provide new insight into plastome evolution in Orchidaceae.

High temperature damage to fatty acids and carbohydrate metabolism in tall fescue by coupling deep transcriptome and metabolome analysis.

High temperature damage impairs the growth of tall fescue by inhibiting secondary metabolites. Little is known about the regulation pattern of the fatty acids and carbohydrate metabolism at the whole-transcriptome level in tall fescue under high temperature stress. Here, two tall fescue genotypes, heat tolerant PI578718 and heat sensitive PI234881 were subjected to high temperature stress for 36 h. PI 578718 showed higher SPAD chloroplast value, lower EL and leaf injury than PI 234881 during the first 36 h high-temperature stress. Furthermore, by transcriptomic analysis, 121 genes were found to be induced during the second energy production phase in tall fescue exposed to high-temperature conditions, indicating that there may be one energy-sensing system in cool-season turfgrass to adapt high-temperature conditions. PI 578718 showed higher differentially expressed unigenes involved in fatty acids and carbohydrate metabolism compared with PI 234881 for 36 h heat stress. Interestingly, a metabolomic analysis using GC-MS uncovered that the sugars and sugar alcohol accounted for more than 65.06% of the total 41 metabolites content and high-temperature elevated the rate to 82.89-91.16% in PI 578718. High-temperature damage decreased the rate of fatty acid in the total 41 metabolites content and PI 578718 showed lower content than in PI 234881, which might be attributed to the down-regulated genes in fatty acid biosynthesis pathway in tall fescue. The integration of deep transcriptome and metabolome analyses provides systems-wide datasets to facilitate the identification of crucial regulation factors in cool-season turfgrass in response to high-temperature damage.

High Sensitivity Snapshot Spectrometer Based on Deep Network Unmixing.

Spectral detection provides rich spectral-temporal information with wide applications. In our previous work, we proposed a dual-path sub-Hadamard-s snapshot Hadamard transform spectrometer (Sub-s HTS). In order to reduce the complexity of the system and improve its performance, we present a convolution neural network-based method to recover the light intensity distribution from the overlapped dispersive spectra, rather than adding an extra light path to capture it directly. In this paper, we construct a network-based single-path snapshot Hadamard transform spectrometer (net-based HTS). First, we designed a light intensity recovery neural network (LIRNet) with an unmixing module (UM) and an enhanced module (EM) to recover the light intensity from the dispersive image. Then, we used the reconstructed light intensity as the original light intensity to recover high signal-to-noise ratio spectra successfully. Compared with Sub-s HTS, the net-based HTS has a more compact structure and high sensitivity. A large number of simulations and experimental results have demonstrated that the proposed net-based HTS can obtain a better-reconstructed signal-to-noise ratio spectrum than the Sub-s HTS because of its higher light throughput.

Marital status is an independent prognostic factor in inflammatory breast cancer patients: an analysis of the surveillance, epidemiology, and end results database.

OBJECTIVES: The aim of this analysis was to study the impact of marital status on inflammatory breast cancer (IBC) patients, as the prognostic impact is yet to be studied in detail. METHODS: Data of IBC patients from 2004 to 2010 were sorted out from the database of surveillance, epidemiology, and end results (SEER), and overall survival (OS) rates and breast cancer-specific survival (CSS) rates were compared between a group of married and unmarried patients. The comparison was performed by Kaplan-Meier method with log-rank test, and multivariate survival analysis of CSS and OS was performed using the Cox proportional hazard model. RESULTS: Data of 1342 patients were collected from the SEER database, on an average 52% of married patients (n = 698, 52.01%) and 48% of unmarried patients (n = 644, 47.99%) for this analysis. Married patients were more likely to be more younger (aged ≤ 56) (52.44% vs. 43.94%), white ethnicity (83.24% vs. 71.58%), HoR positive (48.28% vs. 41.61%), more patients received surgery (78.51% vs. 64.60%), chemotherapy (90.69% vs. 80.12%) and radiotherapy (53.44% vs. 44.41%) compared to unmarried group, and less likely to be AJCC stage IV (26.22% vs. 35.40%) (All P ˂ 0.05). Married patients had better 5-year CSS (74.90% vs. 65.55%, P < 0.0001) and OS rates (45.43% vs. 33.11%, P < 0.0001). The multivariate analysis revealed that marital status is an independent prognostic factor, whereas the data of unmarried patients showed worse CSS (HR 1.188; 95% CI 1.033-1.367; P = 0.016) and OS rates (HR 1.245; 95% CI 1.090-1.421; P = 0.001).The subgroup analysis further revealed that the OS and CSS rates in the married group were better than the unmarried group, regardless of different AJCC stages. CONCLUSION: Marital status was an independent prognostic indicator in IBC patients. As the study reveals, the CSS and OS rates of the married patients were better than those of the unmarried patients.

Preparation of Progesterone Co-Crystals Based on Crystal Engineering Strategies.

Three co-formers of 2-chloro-4-nitroaniline (CNA), 2,5-dihydroxybenzoic acid (DHB), and 4,4'-biphenol (DOD) were selected to prepare the co-crystal of progesterone (PROG) based on crystal engineering strategies. These co-crystals were successfully obtained via slow evaporation from different solutions and were characterized by single-crystal X-ray diffraction spectroscopy, powder X-ray diffraction, IR spectroscopy, and differential scanning calorimetry. Different binding networks were observed in the co-crystal structures of PROG. The PROG-CNA co-crystal had the fastest rates and highest concentrations of PROG in PBS solution compared with PROG or other co-crystals in the dissolution experiments. This might be attributable to more stable and abundant interactions between the PROG and CNA molecules. Our investigations provide positive support for the selection of suitable co-formers using crystal engineering strategies.

Electrically Controlled Nano and Micro Actuation in Memristive Switching Devices with On-Chip Gas Encapsulation.

Nanoactuators are a key component for developing nanomachinery. Here, an electrically driven device yielding actuation stresses exceeding 1 MPa withintegrated optical readout is demonstrated. 10 nm thick Al2 O3 electrolyte films are sandwiched between graphene and Au electrodes. These allow reversible room-temperature solid-state redox reactions, producing Al metal and O2 gas in a memristive-type switching device. The resulting high-pressure oxygen micro-fuel reservoirs are encapsulated under the graphene, swelling to heights of up to 1 µm, which can be dynamically tracked by plasmonic rulers. Unlike standard memristors where the memristive redox reaction occurs in single or few conductive filaments, the mechanical deformation forces the creation of new filaments over the whole area of the inflated film. The resulting on-off resistance ratios reach 108 in some cycles. The synchronization of nanoactuation and memristive switching in these devices is compatible with large-scale fabrication and has potential for precise and electrically monitored actuation technology.

Distinctive Performance of Gemini Surfactant in the Preparation of Hierarchically Porous Carbons via High-Internal-Phase Emulsion Template.

The superior capability of gemini surfactant (GS) in the preparation of hierarchically porous carbons via high-internal-phase emulsion (HIPE) template followed by pyrolysis was confirmed in this work. Polymerized HIPEs (polyHIPEs) of phenol-formaldehyde resin were prepared by cross-linking the continuous phase of HIPEs stabilized by GS. Nonionic surfactant and cationic surfactant were also selected to stabilize HIPE for comparison. From scanning electron microscope observations, polyHIPEs with open-cell pore architectures were obtained with GS as emulsifier (polyHIPEs-GS) and the derived carbon foams (carboHIPEs-GS) well retained the original pore architectures, whereas polyHIPEs obtained using contrastive surfactants showed closed-cell porous structures and notable differences were observed for the derived carboHIPEs. Nitrogen adsorption/desorption measurements indicated that polyHIPEs-GS and carboHIPEs-GS both exhibited hierarchically porous architectures with much higher surface areas (SA) than those of the corresponding contrast samples. Mercury intrusion porosimetry results indicated that carboHIPEs-GS possessed higher SA and higher porosity than that of the contrast samples. The open-cell pore architecture and high SA are favorable to many applications, like energy storage. carboHIPE-GS expectably showed a higher capacitance than that of contrast samples when used as the electrode material of supercapacitor.

Surface polarons and optical micro-cavity modulated broad range multi-mode emission of Te-doped CdS nanowires.

The optical confinement and strong carrier coupling within a semiconductor nanostructure cavity are crucial for the modulation of emission properties. Fundamental understanding of the light-matter interaction in a low dimensional system is important. In this paper, we synthesized high-quality hexagonal Te-doped CdS nanowires by two-step chemical vapor deposition and investigated systematically the doping concentration, temperature, excitation power, excitation wavelength dependent Raman, photoluminescence and carrier lifetime decay. Scanning electron microscopy, energy dispersive x-ray spectrometry and x-ray diffraction confirmed Te-doping in the as-prepared samples. The strong surface optical (SO) phonon mode is observed in the micro-Raman spectra of an individual Te-CdS nanowire, which is unsuitable in large-sized structures. In situ micro-photoluminescence (µ-PL) characterization shows dominant confined defect state emission with whispering gallery mode (WGM) characteristics. The emission peak position shifts under increased excitation power, demonstrating the inelastic scattering by bound carriers. In addition, the short wavelength emission modes are dominant at a low temperature (80 K) while the long wavelength emission modes are dominant at a high temperature (300 K) due to different recombination processes contributing to the WGM resonant bands, which was also confirmed by the time-resolved PL measurement. All these results reflect strong coupling between the surface evanescent-wave in the WGM cavity and the SO phonon/polaron, which will facilitate the rational tailoring of surface/interface relevant properties for nanophotonic device applications.

Quantitative analysis of finasteride tablets dissolution content with non-isotopically labeled internal standard by paper spray ionization mass spectrometry.

Paper spray ionization, one of the ambient mass spectrometry technologies, has been developed to characterize the content of drugs in various complex matrixes including urine, whole blood, dissolution solutions, and so on. An isotopically labeled compound as internal standard is often used in quantitative paper spray ionization experiments. But high cost and difficult to access impede the application of this type of internal standards. Application of non-isotopically labeled compounds as internal standards will make this technology more prevalent. In this paper, we explored the application of finasteride impurity as the internal standard in paper spray ionization-mass spectrometry to measure the dissolution content of finasteride tablets. The new method was optimized and the results were compared to those from high-performance liquid chromatography. The whole analysis time was several minutes and limit of detection for finasteride was around 4.8 ng/mL. The results from paper spray ionization-mass spectrometry were similar to those from high-performance liquid chromatography. Combination of paper spray ionization-mass spectrometry and non-isotopically labeled internal standard renders a new method to analyze drug dissolution content with high specificity, low limit of detection, and simple sample preparation within short time period.