Molecular templating of layered halide perovskite nanowires.

Layered metal-halide perovskites, or two-dimensional perovskites, can be synthesized in solution, and their optical and electronic properties can be tuned by changing their composition. We report a molecular templating method that restricted crystal growth along all crystallographic directions except for [110] and promoted one-dimensional growth. Our approach is widely applicable to synthesize a range of high-quality layered perovskite nanowires with large aspect ratios and tunable organic-inorganic chemical compositions. These nanowires form exceptionally well-defined and flexible cavities that exhibited a wide range of unusual optical properties beyond those of conventional perovskite nanowires. We observed anisotropic emission polarization, low-loss waveguiding (below 3 decibels per millimeter), and efficient low-threshold light amplification (below 20 microjoules per square centimeter).

Contrast-Enhanced CT-Based Deep Learning Radiomics Nomogram for the Survival Prediction in Gallbladder Cancer Postoperative.

RATIONALE AND OBJECTIVES: An accurate prognostic model is essential for the development of treatment strategies for gallbladder cancer (GBC). This study proposes an integrated model using clinical features, radiomics, and deep learning based on contrast-enhanced computed tomography (CT) images for survival prediction in patients with GBC after surgical resection. METHODS: A total of 167 patients with GBC who underwent surgical resection at two medical institutions were retrospectively enrolled. After obtaining the pre-treatment CT images, the tumor lesions were manually segmented, and handcrafted radiomics features were extracted. A clinical prognostic signature and radiomics signature were built using machine learning algorithms based on the optimal clinical features or handcrafted radiomics features, respectively. Subsequently, a DenseNet121 model was employed for transfer learning on the radiomics image data and as the basis for the deep learning signature. Finally, we used logistic regression on the three signatures to obtain the unified multimodal model for comprehensive interpretation and analysis. RESULTS: The integrated model performed better than the other models, exhibiting the highest area under the curve (AUC) of 0.870 in the test set, and the highest concordance index (C-index) of 0.736 in predicting patient survival rates. A Kaplan-Meier analysis demonstrated that patients in high-risk group had a lower survival probability compared to those in low-risk group (log-rank p < 0.05). CONCLUSION: The nomogram is useful for predicting the survival of patients with GBC after surgical resection, helping in the identification of high-risk patients with poor prognosis and ultimately facilitating individualized management of patients with GBC.

Donor hepatic artery reconstruction based on human embryology: A case report.

BACKGROUND: Embryonic hepatic artery anatomy simplifies its identification during liver transplantation. Injuries to the donor hepatic artery can cause complications in this process. The hepatic artery's complex anatomy in adults makes this step challenging; however, during embryonic development, the artery and its branches have a simpler relationship. By restoring the embryonic hepatic artery anatomy, surgeons can reduce the risk of damage and increase the procedure's success rate. This approach can lead to improved patient outcomes and lower complication rates. CASE SUMMARY: In this study, we report a case of donor liver preparation using a donor hepatic artery preparation based on human embryology. During the preparation of the hepatic artery, we restored the anatomy of the celiac trunk, superior mesenteric artery, and their branches to the state of the embryo at 5 wk. This allowed us to dissect the variant hepatic artery from the superior mesenteric artery and left gastric artery during the operation. After implanting the donor liver into the recipient, we observed normal blood flow in the donor hepatic artery, main hepatic artery, and variant hepatic artery, without any leakage. CONCLUSION: Donor hepatic artery preparation based on human embryology can help reduce the incidence of donor hepatic artery injuries during liver transplantation.

Light-Emitting Organic Semiconductor-Incorporated Perovskites: Fundamental Properties and Device Applications.

Recently, organic semiconductor-incorporated perovskites (OSiPs) have emerged as a new subclass of next-generation organic-inorganic hybrid materials. OSiPs combine the advantages of organic semiconductors, such as large design windows and tunable optoelectronic functionalities, with the excellent charge-transport properties of the inorganic metal-halide counterparts. OSiPs provide a new materials platform for the exploitation of charge and lattice dynamics at the organic-inorganic interfaces for various applications. This Perspective reviews recent achievements in OSiPs highlighting the benefits from organic semiconductor incorporation and elucidates the fundamental light-emitting mechanism, energy transfer, as well as band alignment structures at the organic-inorganic interface. Insights on the emission tunability lead toward a discussion of the potential of OSiPs in light-emitting applications, such as perovskite light-emitting diodes or lasing systems.

Metal-Free Organic Phosphors toward Fast and Efficient Room-Temperature Phosphorescence.

ConspectusMetal-free purely organic phosphors (POPs) are promising materials for display technologies, solid-state lighting, and sensors platforms because of their advantageous properties such as large design windows, easy processability, and economic material cost. Unlike inorganic semiconductors, creating the conditions for triplet excitons to produce light in organic materials is a demanding task because of the presence of electron spin configurations that undergo spin-forbidden transitions, which is usually facilitated by spin-orbit coupling (SOC). In the absence of heavy metals, however, the SOC efficiency in POPs remains low, and consequently, external nonradiative photophysical processes will also severely affect triplet excitons. Addressing these challenges requires the development of rational molecular design principles to accurately account for how all conceivable structural, electronic, chemical, compositional factors affect materials performance.This Account summarizes important molecular design and matrix engineering strategies to tackle the two key challenges for POPs─boosting SOC efficiencies and suppressing nonradiative decays. We start by reviewing the fundamental understanding of internal and external factors affecting the emission efficiencies of POPs, including the theory behind SOC and the origin of nonradiative decays. Subsequently, we discuss the design of contemporary POP systems on the basis of research insights from our group and others, where SOC is mostly promoted by heavy atom effects and the El-Sayed rule. On one hand, nonmetal heavy atoms including Br, I, or Se provide the heavy atom effects to boost SOC. On the other hand, the El-Sayed rule addresses the necessity of orbital angular momentum change in SOC and the general utilization of carbonyl, heterocyclic rings, and other moieties with rich nonbonding electrons. Because of the slow-decaying nature of triplet excitons, engineering the matrices of POPs is critical to effectively suppress collisional quenching as the major nonradiative decay route, thus achieving POPs with decent room temperature quantum efficiency. For that purpose, crystalline or rigid amorphous matrices have been implemented along with specific intermolecular forces between POPs and their environment.Despite the great efforts made in the past decade, the intrinsic SOC efficiencies of POPs remain low, and their emission lifetimes are pinned in the millisecond to second regime. While this is beneficial for POPs with ultralong emission, designing high-SOC POPs with simultaneous fast decay and high quantum efficiencies is particularly advantageous for display systems. Following the design of contemporary POPs, we will discuss molecular design descriptors that could potentially break the current limit to boost internal SOC in purely organic materials. Our recently developed concept of "heavy atom oriented orbital angular momentum manipulation" will be discussed, accompanied by a rich and expanded library of fast and efficient POP molecules, which serves as a stepping stone into the future of this field. We will conclude this Account by discussing the noteworthy application of POPs in organic light-emitting diodes (OLEDs), solid-state lighting, and sensors, as well as the remaining challenges in the design of fast and efficient POPs.

Heavy atom oriented orbital angular momentum manipulation in metal-free organic phosphors.

Metal-free purely organic phosphors (POPs) are emerging materials for display technologies, solid-state lighting, and chemical sensors. However, due to limitations in contemporary design strategies, the intrinsic spin-orbit coupling (SOC) efficiency of POPs remains low and their emission lifetime is pinned in the millisecond regime. Here, we present a design concept for POPs where the two main factors that control SOC-the heavy atom effect and orbital angular momentum-are tightly coupled to maximize SOC. This strategy is bolstered by novel natural-transition-orbital-based computational methods to visualize and quantify angular momentum descriptors for molecular design. To demonstrate the effectiveness of this strategy, prototype POPs were created having efficient room-temperature phosphorescence with lifetimes pushed below the millisecond regime, which were enabled by boosted SOC efficiencies beyond 102 cm-1 and achieved record-high efficiencies in POPs. Electronic structure analysis shows how discrete tuning of heavy atom effects and orbital angular momentum is possible within the proposed design strategy, leading to a strong degree of control over the resulting POP properties.

Predicting the potential global distribution of Sapindus mukorossi under climate change based on MaxEnt modelling.

Sapindus mukorossi (S. mukorossi) is an important biological washing material and biomass energy tree species whose peel is rich in saponins, and its kernels have a high oil content. We used the maximum entropy model (MaxEnt) to predict the suitable habitats of S. mukorossi globally, screen the dominant environmental factors affecting its distribution and analyse the changes in its suitable habitats under climate change from prehistory to the future, and the results will provide a scientific basis for germplasm resource collection, protection, introduction and cultivation. Twenty-two environmental variables and global distribution data for S. mukorossi were used to construct the species distribution model, and the receiver operating characteristic (ROC) curve was used to verify the accuracy of the model. The dominant environmental factors were screened through the jackknife method, and then, the geographical information system (ArcGIS) was used to complete the grade of suitable habitat division and area calculation. The results showed that the MaxEnt model had an excellent predictive effect, and the area under the ROC curve (AUC) value was as high as 0.969. The precipitation of the warmest quarter (Bio18), the minimum temperature of the coldest month (Bio6), temperature seasonality (Bio4) and isothermality (Bio3) were the dominant environmental factors that affected the distribution of S. mukorossi. The largest area of the world's suitable habitats occurred during the last interglacial (LIG) (772.69 × 104 km2), and the area decreased sharply (614.46 × 104 km2) during the last glacial maximum (LGM). The area of suitable habitat showed an increasing trend during the Mid-Holocene (MH) and currently, with areas of 631.06 × 104 km2 and 706.82 × 104 km2, respectively. The area of suitable habitats for S. mukorossi globally was 718.35 × 104 km2 (SSP1-2.6), 636.85 × 104 km2 (SSP2-4.5), 657.64 × 104 km2 (SSP3-7.0) and 675.89 × 104 km2 (SSP5-8.5) under the four scenarios of the future climate. The area increased only in the SSP1 scenario. In summary, globally, the suitable area of S. mukorossi tended to migrate to higher latitudes and decrease in area with future climate change.

Comparative transcriptomics provides a strategy for phylogenetic analysis and SSR marker development in Chaenomeles.

The genus Chaenomeles has long been considered an important ornamental, herbal and cash crop and is widely cultivated in East Asia. Traditional studies of Chaenomeles mainly focus on evolutionary relationships at the phenotypic level. In this study, we conducted RNA-seq on 10 Chaenomeles germplasms supplemented with one outgroup species, Docynia delavayi (D. delavayi), on the Illumina HiSeq2500 platform. After de novo assemblies, we generated from 40,084 to 49,571 unigenes for each germplasm. After pairwise comparison of the orthologous sequences, 9,659 orthologues within the 11 germplasms were obtained, with 6,154 orthologous genes identified as single-copy genes. The phylogenetic tree was visualized to reveal evolutionary relationships for these 11 germplasms. GO and KEGG analyses were performed for these common single-copy genes to compare their functional similarities and differences. Selective pressure analysis based on 6,154 common single-copy genes revealed that 45 genes were under positive selection. Most of these genes are involved in building the plant disease defence system. A total of 292 genes containing simple sequence repeats (SSRs) were used to develop SSR markers and compare their functions in secondary metabolism pathways. Finally, 10 primers were chosen as SSR marker candidates for Chaenomeles germplasms by comprehensive standards. Our research provides a new methodology and reference for future related research in Chaenomeles and is also useful for improvement, breeding and selection projects in other related species.

Charge Transfer as the Key Parameter Affecting the Color Purity of Thermally Activated Delayed Fluorescence Emitters.

The key factors determining the emission bandwidth of thermally activated delayed fluorescence (TADF) are investigated by combining computational and experimental approaches. To achieve high internal quantum efficiencies in a metal-free organic light-emitting diode via TADF, the first triplet (T1) to first singlet (S1) reverse intersystem crossing is promoted by configuring molecules in an electron donor-acceptor (D-A) alternation with a large dihedral angle, which results in a small energy gap (ΔEST) between S1 and T1 levels. This allows for effective non-radiative up-conversion of triplet excitons to singlet excitons that fluoresce. However, this traditional molecular design of TADF results in broad emission spectral bands (full-width at half-maximum = 70-100 nm). Despite reports suggesting that suppressing the D-A dihedral rotation narrows the emission band, the origin of emission broadening remains elusive. Indeed, our results suggest that the intrinsic TADF emission bandwidth is primarily determined by the charge transfer character of the molecule, rather than its propensity for rotational motion, which offers a renewed perspective on the rational molecular design of organic emitters exhibiting sharp emission spectra.

Organic Light-Emitting Diode Employing Metal-Free Organic Phosphor.

Metal-free organic phosphorescent materials are promising alternatives to the organometallic counterparts predominantly adopted in organic light-emitting diodes due to their low cost, chemical stability, and large molecular design window. However, only a few reports on OLED devices incorporating metal-free organic phosphors have been presented due to the lack of understanding on material properties, device physics, and device fabrication processes. Here, we report a tailor-designed novel fluorene-based organic phosphor with efficient spin-orbit coupling activated by bromine, aromatic carbonyl, and spiro-annulated phenyl moieties. Photoluminescence quantum yield of 24.0% was achieved when doped in optically inert amorphous polymer hosts. Effects of OLED host materials on the phosphor were investigated in terms of color purity, suppression of exciplex emission, and restraint of molecular motion. Bright green phosphorescence emission (1430 cd/m2 at 100 mA/cm2) was realized with 2.5% maximum external quantum efficiency at 1 mA/cm2.

The complete chloroplast genome sequences of two Chaenomeles species (Chaenomeles cathayensis and Chaenomeles thibetica).

The complete chloroplast genome sequence of Chaenomeles cathayensis and Chaenomeles thibetica was characterized from Illumina pair-end sequencing. The length of C. cathayensis and C. thibetica chloroplast genome of was 159,875 bp and 159,907 bp, respectively. The C. cathayensis chloroplast genome contained a large single-copy region (LSC) of 87,813bp, a small single-copy region (SSC) of 19,304 bp, and two inverted repeat (IR) regions of 26,379 bp, which is a quadripartite structure. Similarity, The C. thibetica chloroplast genome also contained a quadripartite structure, including a LSC region (87,851 bp), a SSC region (19,298 bp), and two IR regions (26,379 bp). The overall GC content of C. cathayensis and C. thibetica are both 36.57%. The C. cathayensis and C. thibetica chloroplast genome contains 130 complete genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The C. thibetica chloroplast genome contains 130 complete genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. The neighbour-joining phylogenetic analysis showed that C. cathayensis and C. thibetica clustered together, indicated that C. cathayensis and C. thibetica have closed evolutionary relationship compared with other Chaenomeles species.

An Anterior Cruciate Ligament Failure Mechanism.

BACKGROUND: Nearly three-quarters of anterior cruciate ligament (ACL) injuries occur as "noncontact" failures from routine athletic maneuvers. Recent in vitro studies revealed that repetitive strenuous submaximal knee loading known to especially strain the ACL can lead to its fatigue failure, often at the ACL femoral enthesis. HYPOTHESIS: ACL failure can be caused by accumulated tissue fatigue damage: specifically, chemical and structural evidence of this fatigue process will be found at the femoral enthesis of ACLs from tested cadaveric knees, as well as in ACL explants removed from patients undergoing ACL reconstruction. STUDY DESIGN: Controlled laboratory study. METHODS: One knee from each of 7 pairs of adult cadaveric knees were repetitively loaded under 4 times-body weight simulated pivot landings known to strain the ACL submaximally while the contralateral, unloaded knee was used as a comparison. The chemical and structural changes associated with this repetitive loading were characterized at the ACL femoral enthesis at multiple hierarchical collagen levels by employing atomic force microscopy (AFM), AFM-infrared spectroscopy, molecular targeting with a fluorescently labeled collagen hybridizing peptide, and second harmonic imaging microscopy. Explants from ACL femoral entheses from the injured knee of 5 patients with noncontact ACL failure were also characterized via similar methods. RESULTS: AFM-infrared spectroscopy and collagen hybridizing peptide binding indicate that the characteristic molecular damage was an unraveling of the collagen molecular triple helix. AFM detected disruption of collagen fibrils in the forms of reduced topographical surface thickness and the induction of ~30- to 100-nm voids in the collagen fibril matrix for mechanically tested samples. Second harmonic imaging microscopy detected the induction of ~10- to 100-µm regions where the noncentrosymmetric structure of collagen had been disrupted. These mechanically induced changes, ranging from molecular to microscale disruption of normal collagen structure, represent a previously unreported aspect of tissue fatigue damage in noncontact ACL failure. Confirmatory evidence came from the explants of 5 patients undergoing ACL reconstruction, which exhibited the same pattern of molecular, nanoscale, and microscale structural damage detected in the mechanically tested cadaveric samples. CONCLUSION: The authors found evidence of accumulated damage to collagen fibrils and fibers at the ACL femoral enthesis at the time of surgery for noncontact ACL failure. This tissue damage was similar to that found in donor knees subjected in vitro to repetitive 4 times-body weight impulsive 3-dimensional loading known to cause a fatigue failure of the ACL. CLINICAL RELEVANCE: These findings suggest that some ACL injuries may be due to an exacerbation of preexisting hierarchical tissue damage from activities known to place larger-than-normal loads on the ACL. Too rapid an increase in these activities could cause ACL tissue damage to accumulate across length scales, thereby affecting ACL structural integrity before it has time to repair. Prevention necessitates an understanding of how ACL loading magnitude and frequency are anabolic, neutral, or catabolic to the ligament.

Rapid classification of Chinese quince (Chaenomeles speciosa Nakai) fruit provenance by near-infrared spectroscopy and multivariate calibration.

The quality of Chinese quince fruit is a significant factor for medicinal materials, influencing the quality of the medicine. However, it is difficult to distinguish different types of Chinese quince fruit. The main objective of this work was to use near-infrared (NIR) spectroscopy, which is a rapid and non-destructive analysis method, to classify the varieties of Chinese quince fruits. Raw spectra in the range of 1000 to 2500 nm were combined with linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), and support vector machines (SVMs) for classification. The first three principal component analysis (PCA) scores were used as input variables to build LDA, QDA, and SVM discriminant models. The results indicate that all three of these methods are effective for distinguishing the different types of Chinese quince fruit. The classification accuracies for LDA, QDA, and SVM are 94, 96, and 98 %, respectively. QDA led to high-level classification accuracy of Chinese quince fruit.

Phylogenetic and Taxonomic Status Analyses of the Abaso Section from Multiple Nuclear Genes and Plastid Fragments Reveal New Insights into the North America Origin of Populus (Salicaceae).

Although, the Abaso section is widely accepted as an independent section, the taxonomic status of Populus mexicana (section Abaso) has not yet been resolved due to the limited availability markers and/or the lack of P. mexicana specimens in previous studies. Thirty-one poplar species that represent six sections of the Populus genus were sampled, and 23 single-copy nuclear DNA and 34 chloroplast fragments were sequenced. The present study obtained two updated phylogenies of Populus. We found that monophyly of the genus Populus is strongly supported by nuclear and plastid gene, which is consistent with previous studies. P. mexicana, diverged first in the nuclear DNA tree, which occupied the basal position, implying that the section Abaso may be the most ancestral lineage in extant populous species. Given that the short branches and low statistical support for the divergence of sections Abaso and Turanga, this observation probably indicated that a rapid radiation evolution following the early split of the genus Populus. In the plastid tree, P. mexicana clustered with modern-day species of section Tacamahaca in the plastid tree. Based on cytoplasmic and single-copy nuclear marker sequences, we hypothesized that chloroplast capture resulted in the inconsistent position of P. mexicana between the phylogenetic trees. Given the first unequivocal records of poplar fossils from the Eocene with similar leaf morphology to the extant P. mexicana and the phylogenetic positions of P. mexicana in our study, we support the hypothesis that the Populus genus originated in North America, which will provide new insights to the development of the origin of Populus species.

Pyrolysis of Animal Bones with Vitamin B12: A Facile Route to Efficient Transition Metal-Nitrogen-Carbon (TM-N-C) Electrocatalysts for Oxygen Reduction.

By pyrolyzing cattle bones, hierarchical porous carbon (HPC) networks with a high surface area (2520 m(2) g(-1) ) and connected pores were prepared at a low cost and large scale. Subsequent co-pyrolysis of HPC with vitamin B12 resulted in the formation of three-dimensional (3D) hierarchically structured porous cobalt-nitrogen-carbon (Co-N-HPC) electrocatalysts with a surface area as high as 859 m(2) g(-1) as well as a higher oxygen reduction reaction (ORR) electrocatalytic activity, better operation stability, and higher tolerance to methanol than the commercial Pt/C catalyst in alkaline electrolyte.

Synthesis and evaluation of new α-methylene-γ-lactone carbamates with NO production inhibitory effects in lipopolysaccharide-induced RAW 264.7 macrophages.

A series of new α-methylene-γ-lactone carbamates were synthesized by an asymmetric synthetic route. The activities on inhibiting nitric oxide (NO) release of these compounds were evaluated in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. The results indicated that most of the compounds except one exhibited potent NO inhibitory effect with IC50 value more than 2 µΜ. The cytotoxicities of these compounds were estimated via MTT assays. The results suggested that six compounds were accompanied by low cytotoxicity. The structure-activity relationships were also discussed. The S configuration of C3 on lactones ring would be more helpful to NO inhibitory effect.

Synthesis and structure-activity relationships of guaiane-type sesquiterpene lactone derivatives with respect to inhibiting NO production in lipopolysaccharide-induced RAW 264.7 macrophages.

A guaiane framework was scaffolded by photochemical rearrangement reactions using α-santonin 1 as a starting material. Then, using a series of reactions, we synthesized the guaiane-type sesquiterpene lactone 5 in high yield. The inhibitory activities of compound 5 and of a series of derivatives on nitric oxide (NO) release were evaluated in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. Compounds 6g, 7h, 7i, 7k and 8g, exhibited significant inhibitory effects on NO production, with IC50 values of 14.8, 22.3, 18.3, 17.4 and 7.0 µM, respectively. Their cytotoxicities were also estimated using an MTT assay. The structure-activity relationships of these compounds were also discussed.