Encapsulation and Evolution of Polyynes Inside Single-Walled Carbon Nanotubes.

Polyyne is an sp-hybridized linear carbon chain (LCC) with alternating single and triple carbon-carbon bonds. Polyyne is very reactive; thus, its structure can be easily damaged through a cross-linking reaction between the molecules. The longer the polyyne is, the more unstable it becomes. Therefore, it is difficult to directly synthesize long polyynes in a solvent. The encapsulation of polyynes inside carbon nanotubes not only stabilizes the molecules to avoid cross-linking reactions, but also allows a restriction reaction to occur solely at the ends of the polyynes, resulting in long LCCs. Here, by controlling the diameter of single-walled carbon nanotubes (SWCNTs), polyynes were filled with high yield below room temperature. Subsequent annealing of the filled samples promoted the reaction between the polyynes, leading to the formation of long LCCs. More importantly, single chiral (6,5) SWCNTs with high purity were used for the successful encapsulation of polyynes for the first time, and LCCs were synthesized by coalescing the polyynes in the (6,5) SWCNTs. This method holds promise for further exploration of the synthesis of property-tailored LCCs through encapsulation inside different chiral SWCNTs.

A DNA-Modularized STING Agonist with Macrophage-Selectivity and Programmability for Enhanced Anti-Tumor Immunotherapy.

The activation of cyclic GMP-AMP (cGAMP) synthase (cGAS) and its adaptor, stimulator of interferon genes (STING), is known to reprogram the immunosuppressive tumor microenvironment for promoting antitumor immunity. To enhance the efficiency of cGAS-STING pathway activation, macrophage-selective uptake, and programmable cytosolic release are crucial for the delivery of STING agonists. However, existing polymer- or lipid-based delivery systems encounter difficulty in integrating multiple functions meanwhile maintaining precise control and simple procedures. Herein, inspired by cGAS being a natural DNA sensor, a modularized DNA nanodevice agonist (DNDA) is designed that enable macrophage-selective uptake and programmable activation of the cGAS-STING pathway through precise self-assembly. The resulting DNA nanodevice acts as both a nanocarrier and agonist. Upon local administration, it demonstrates the ability of macrophage-selective uptake, endosomal escape, and cytosolic release of the cGAS-recognizing DNA segment, leading to robust activation of the cGAS-STING pathway and enhanced antitumor efficacy. Moreover, DNDA elicits a synergistic therapeutic effect when combined with immune checkpoint blockade. The study broadens the application of DNA nanotechnology as an immune stimulator for cGAS-STING activation.

Proteomic Identification of Small Extracellular Vesicle Proteins LAMB1 and Histone H4 for Prostate Cancer Diagnosis and Risk Stratification.

Diagnosis and stratification of prostate cancer (PCa) patients using the prostate-specific antigen (PSA) test is challenging. Extracellular vesicles (EVs), as a new star of liquid biopsy, has attracted interest to complement inaccurate PSA screening and invasiveness of tissue biopsy. In this study, a panel of potential small EV (sEV) protein biomarkers is identified from PCa cell lines using label-free LC-MS/MS proteomics. These biomarkers underwent further validation with plasma and urine samples from different PCa stages through parallel reaction monitoring-based targeted proteomics, western blotting, and ELISA. Additionally, a tissue microarray containing cancerous and noncancerous tissues is screened to provide additional evidence of selected sEV proteins associated with cancer origin. Results indicate that sEV protein LAMB1 is highly expressed in human plasma of metastatic PCa patients compared with localised PCa patients and control subjects, while sEV protein Histone H4 is highly expressed in human urine of high-risk PCa patients compared to low-risk PCa patients and control subjects. These two sEV proteins demonstrate higher specificity and sensitivity than the PSA test and show promise for metastatic PCa diagnosis, progression monitoring, and risk stratification.

Effects of sowing patterns on nitrogen utilization and yield formation of winter wheat in the western Huang-Huai-Hai region.

To examine the differences of three improved sowing methods in winter wheat yield and nitrogen efficiency and reveal the characteristics responsible for such differences, we conducted field experiments in the Jinnan area of the western Huang-Huai-Hai wheat region for three consecutive seasons from 2016 to 2019. The three improved sowing methods were wide space sowing (WSS), furrow sowing in moisture soil (FS), and three-dimensional uniform sowing (TDUS), with conventional drilling sowing (CDS) as the control. The results showed that meteorological factors such as accumulated temperature, solar radiation, and precipitation in the growing seasons from 2016 to 2019 showed great intra- and inter-annual variations. Compared with CDS, the improved sowing methods (WSS, FS, and TDUS) enhanced spike number per unit area and increased grain yield in three growing seasons by 18.3%-55.5%, 8.6%-22.2%, and 10.9%-39.5%, respectively. The three methods increased nitrogen uptake efficiency (NEup) by 5.8%-57.1%, pre-flowering nitrogen transfer ratio (Np/Nt) by 3.0%-15.3%, and nitrogen efficiency by 7.9%-35.7%, respectively. We developed a structural equation model (SEM) by integrating meteorological factors and experimental variables. The results showed that the three improved sowing methods could reduce the effects of extreme low temperature on wheat plant population, increase NEup and Np/Nt, and provide sufficient nitrogen supply to the grains of high-spike number wheat population for high yield and high nitrogen efficiency. In summary, our results demonstrated that WSS, FS, and TDUS all improved NEup and Np/Nt in the 2016-2017 season when meteorological conditions were favorable for wheat growth, and enhanced yield components with high SN, leading to high yield and high nitrogen efficiency. In contrast, in both 2017-2018 and 2018-2019 seasons with extremely low temperature and uneven distribution of meteorological conditions, WSS had a higher number of tillers at the jointing stage and enhanced pre-flowering nitrogen uptake and translocation, whereas TDUS had a relatively stable nitrogen uptake rate, leading to a stable grain yield.

Flexible Curcumin-Loaded Zn-MOF Hydrogel for Long-Term Drug Release and Antibacterial Activities.

Management of chronic inflammation and wounds has always been a key issue in the pharmaceutical and healthcare sectors. Curcumin (CCM) is an active ingredient extracted from turmeric rhizomes with antioxidant, anti-inflammatory, and antibacterial activities, thus showing significant effectiveness toward wound healing. However, its shortcomings, such as poor water solubility, poor chemical stability, and fast metabolic rate, limit its bioavailability and long-term use. In this context, hydrogels appear to be a versatile matrix for carrying and stabilizing drugs due to their biomimetic structure, soft porous microarchitecture, and favorable biomechanical properties. The drug loading/releasing efficiencies can also be controlled via using highly crystalline and porous metal-organic frameworks (MOFs). Herein, a flexible hydrogel composed of a sodium alginate (SA) matrix and CCM-loaded MOFs was constructed for long-term drug release and antibacterial activity. The morphology and physicochemical properties of composite hydrogels were analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Raman spectroscopy, and mechanical property tests. The results showed that the composite hydrogel was highly twistable and bendable to comply with human skin mechanically. The as-prepared hydrogel could capture efficient CCM for slow drug release and effectively kill bacteria. Therefore, such composite hydrogel is expected to provide a new management system for chronic wound dressings.

Yiwei decoction promotes apoptosis of gastric cancer cells through spleen-derived exosomes.

Yiwei decoction (YWD) is a formula of traditional Chinese medicine (TCM) that is clinically effective for the prevention and treatment of gastric cancer recurrence and metastasis. According to the theory of TCM, YWD tonifies the body and strengthens the body's resistance to gastric cancer recurrence and metastasis potentially via the immune regulation of the spleen. The aims of the present study were to investigate whether YWD-treated spleen-derived exosomes in rats inhibit the proliferation of tumor cells, to elucidate the anticancer effects of YWD, and to provide evidence supporting the use of YWD as a new clinical treatment for gastric cancer. Spleen-derived exosomes were obtained by ultracentrifugation and identified by transmission electron microscopy, nanoparticle tracking analysis, and western blot analysis. The location of the exosomes in tumor cells was then determined by immunofluorescence staining. After tumor cells were treated with different concentrations of exosomes, the effect of exosomes on cell proliferation was determined by cell counting kit 8 (CCK8) and colony formation assays. Tumor cell apoptosis was detected by flow cytometry. Particle analysis and western blot analysis identified the material extracted from spleen tissue supernatant as exosomes. Immunofluorescence staining showed that spleen-derived exosomes were taken up by HGC-27 cells, and the CCK8 assay confirmed that the relative tumor inhibition rate of YWD-treated spleen-derived exosomes in the 30 µg/mL reached 70.78% compared to control exosomes in the 30 µg/mL (p < 0.05). Compared to control exosomes in the 30 µg/mL, the colony formation assay indicated that YWD-treated spleen-derived exosomes in the 30 µg/mL colonies have decreased by 99.03% (p < 0.01). Moreover, flow cytometry analysis showed that treatment with YWD-treated exosomes in the 30 µg/mL increased the apoptosis rate to 43.27%, which was significantly higher than that of the control group in the 30 µg/mL (25.91%) (p < 0.05). In conclusion, spleen-derived exosomes from YWD-treated animals inhibit the proliferation of HGC-27 cells via inducing apoptosis, suggesting that spleen-derived exosomes are involved in mediating the antitumor effect of YWD. These results demonstrated a novel exosome-mediated anticancer effect of YWD as a TCM formula, thereby supporting the use of YWD-treated exosomes as a new approach for the clinical treatment of gastric cancer.

Otosyphilis as a rare cause of secondary benign paroxysmal positional vertigo: a case report.

Otosyphilis is a rare cause of audiovestibular dysfunction that can easily be misdiagnosed. Here, we report a rare case in which a patient presented with secondary benign paroxysmal positional vertigo (BPPV) 2 weeks after symptoms of otosyphilis appeared. The Dix-Hallpike test showed a classical response in the head-hanging left position. The patient was treated with intravenous penicillin G and the canalith repositioning maneuver, which completely resolved the vertigo. The patient's audiovestibular symptoms resolved gradually. The elevated cerebrospinal fluid (CSF) white blood cell (WBC) count returned to normal and the results of the Treponema pallidum particle agglutination (TPPA) test were negative at the 3-month follow-up. This report suggests that otosyphilis should be considered in the differential diagnosis of audiovestibular dysfunction in patients at risk. Additionally, clinicians should remain vigilant about the possibility of secondary BPPV in patients with otosyphilis who report positional vertigo.

Gold Nanocage-Based Photothermal Ablation Facilitates In Situ Vaccination for Melanoma Therapy.

Cancer immunotherapy represents a medical breakthrough, but there are still many patients unable to benefit from it because of the low response rate. The immunosuppressive tumor microenvironment (TME) is the main barrier to immunotherapy. Alleviating intratumoral immunosuppression is critical for improving the immune therapeutic efficacy. This work developed an in situ vaccination strategy by using gold nanocage (AuNC)-based photothermal effect in combination with an adjuvant and PD-L1 suppressor. In specific, this therapeutic strategy included three components: AuNCs as an inducer for tumor antigen production via photothermal ablation, CpG oligodeoxynucleotides as an adjuvant to amplify immune responses, and JQ1 as a PD-L1 suppressor to inhibit an immune checkpoint. The results showed that the in situ vaccination efficiently activated dendritic cells and primed T cells and exhibited a high therapeutic efficacy in the melanoma-bearing mice. This therapeutic strategy can increase the infiltration of cytotoxic T lymphocytes, suppress the PD-L1 expression in the tumor, and repolarize tumor-associated macrophages from pro-tumor M2 to the anti-tumor M1 phenotype, thereby remodeling the TME via regulating the innate immune and adaptive immune responses.

An Effective Mechanism for the Early Detection and Containment of Healthcare Worker Infections in the Setting of the COVID-19 Pandemic: A Systematic Review and Meta-Synthesis.

The COVID-19 pandemic has exposed healthcare workers (HCWs) to serious infection risks. In this context, the proactive monitoring of HCWs is the first step toward reducing intrahospital transmissions and safeguarding the HCW population, as well as reflecting the preparedness and response of the healthcare system. As such, this study systematically reviewed the literature on evidence-based effective monitoring measures for HCWs during the COVID-19 pandemic. This was followed by a meta-synthesis to compile the key findings, thus, providing a clearer overall understanding of the subject. Effective monitoring measures of syndromic surveillance, testing, contact tracing, and exposure management are distilled and further integrated to create a whole-process monitoring workflow framework. Taken together, a mechanism for the early detection and containment of HCW infections is, thus, constituted, providing a composite set of practical recommendations to healthcare facility leadership and policy makers to reduce nosocomial transmission rates while maintaining adequate staff for medical services. In this regard, our study paves the way for future studies aimed at strengthening surveillance capacities and upgrading public health system resilience, in order to respond more efficiently to future pandemic threats.

Expression characterization and cross-species complementation uncover the functional conservation of YABBY genes for leaf abaxial polarity and carpel polarity establishment in Saccharum spontaneum.

BACKGROUND: Cell polarity establishment and maintenance is indispensable for plant growth and development. In plants, the YABBY transcription factor family has a distinct role in leaf asymmetric polarity establishment and lateral organ initiation. However, for the important sugar crop Saccharum, little information on YABBY genes is available. RESULTS: In this study, a total of 20 sequences for 7 SsYABBY genes were identified in the sugarcane genome, designated as SsYABBY1-7 based on their chromosome locations, and characterized by phylogenetic analysis. We provided a high-resolution map of SsYABBYs' global expression dynamics during vegetative and reproductive organ morphogenesis and revealed that SsYABBY3/4/5 are predominately expressed at the seedling stage of stem and leaf basal zone; SsYABBY2/5/7 are highly expressed in ovules. Besides, cross-species overexpression and/or complementation verified the conserved function of SsYABBY2 in establishing leaf adaxial-abaxial polarity and ovules development. We found that the SsYABBY2 could successfully rescue the leaves curling, carpel dehiscence, and ovule abortion defects in Arabidopsis crc mutant. CONCLUSIONS: Collectively, our study demonstrates that SsYABBY genes retained a conserved function in establishing and preserving leaf adaxial-abaxial polarity and lateral organ development during evolution.

Interspecific complementation-restoration of phenotype in Arabidopsis cuc2cuc3 mutant by sugarcane CUC2 gene.

BACKGROUND: In plants, a critical balance between differentiation and proliferation of stem cells at the shoot apical meristem zone is essential for proper growth. The spatiotemporal regulation of some crucial genes dictates the formation of a boundary within and around budding organs. The boundary plays a pivotal role in distinguishing one tissue type from another and provides a defined shape to the organs at their developed stage. NAM/CUC subfamily of the NAC transcription factors control the boundary formation during meristematic development. RESULTS: Here, we have identified the CUP-SHAPED COTYLEDON (CUC) genes in sugarcane and named SsCUC2 (for the orthologous gene of CUC1 and CUC2) and SsCUC3. The phylogenetic reconstruction showed that SsCUCs occupy the CUC2 and CUC3 clade together with monocots, whereas eudicot CUC2 and CUC3 settled separately in the different clade. The structural analysis of CUC genes showed that most of the CUC3 genes were accompanied by an intron gain during eudicot divergence. Besides, the study of SsCUCs expression in the RNA-seq obtained during different stages of ovule development revealed that SsCUCs express in developing young tissues, and the expression of SsCUC2 is regulated by miR164. We also demonstrate that SsCUC2 (a monocot) could complement the cuc2cuc3 mutant phenotype of Arabidopsis (eudicot). CONCLUSIONS: This study further supports that CUC2 has diverged in CUC1 and CUC2 during the evolution of monocots and eudicots from ancestral plants. The functional analysis of CUC expression patterns during sugarcane ovule development and ectopic expression of SsCUC2 in Arabidopsis showed that SsCUC2 has a conserved role in boundary formation. Overall, these findings improve our understanding of the functions of sugarcane CUC genes. Our results reveal the crucial functional role of CUC genes in sugarcane.

TRM61 is essential for Arabidopsis embryo and endosperm development.

Post-transcriptional modifications of tRNA molecules play crucial roles in gene expression and protein biosynthesis. Across the genera, methylation of tRNAs at N1 of adenosine 58 (A58) by AtTRM61/AtTRM6 complex plays a critical role in maintaining the stability of initiator methionyl-tRNA (tRNAiMet). Recently, it was shown that mutation in AtTRM61 or AtTRM6 leads to seed abortion. However, a detailed study about the AtTRM61/AtTRM6 function in plants remains vague. Here, we found that AtTRM61 has a conserved functional structure and possesses conserved binding motifs for cofactor S-adenosyl-L-methionine (AdoMet). Mutations of the complex subunits AtTRM61/AtTRM6 result in embryo and endosperm developmental defects. The endosperm and embryo developmental defects were conditionally complemented by Attrm61-1/ + FIS2pro::AtTRM61 and Attrm61-1/ + ABI3pro::AtTRM61 indicating that AtTRM61 is required for early embryo and endosperm development. Besides, the rescue of the fertility defects in trm61/ + by overexpression of initiator tRNA suggests that AtTRM61 mutation could diminish tRNAiMet stability. Moreover, using yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays, we showed that AtMPK4 physically interacts with AtTRM61. The data presented here suggest that AtTRM61 has a conserved structure and function in Arabidopsis. Also, AtTRM61 may be required for tRNAiMet stability, embryo and endosperm development.

Genetically-engineered "all-in-one" vaccine platform for cancer immunotherapy.

An essential step for cancer vaccination is to break the immunosuppression and elicit a tumor-specific immunity. A major hurdle against cancer therapeutic vaccination is the insufficient immune stimulation of the cancer vaccines and lack of a safe and efficient adjuvant for human use. We discovered a novel cancer immunostimulant, trichosanthin (TCS), that is a clinically used protein drug in China, and developed a well-adaptable protein-engineering method for making recombinant protein vaccines by fusion of an antigenic peptide, TCS, and a cell-penetrating peptide (CPP), termed an "all-in-one" vaccine, for transcutaneous cancer immunization. The TCS adjuvant effect on antigen presentation was investigated and the antitumor immunity of the vaccines was investigated using the different tumor models. The vaccines were prepared via a facile recombinant method. The vaccines induced the maturation of DCs that subsequently primed CD8+ T cells. The TCS-based immunostimulation was associated with the STING pathway. The general applicability of this genetic engineering strategy was demonstrated with various tumor antigens (i.e., legumain and TRP2 antigenic peptides) and tumor models (i.e., colon tumor and melanoma). These findings represent a useful protocol for developing cancer vaccines at low cost and time-saving, and demonstrates the adjuvant application of TCS-an old drug for a new application.

Identification and evaluation of the novel genes for transcript normalization during female gametophyte development in sugarcane.

BACKGROUND: Sugarcane (Saccharum spontaneum L.), the major sugar and biofuel feedstock crop, is cultivated mainly by vegetative propagation worldwide due to the infertility of female reproductive organs resulting in the reduction of quality and output of sugar. Deciphering the gene expression profile during ovule development will improve our understanding of the complications underlying sexual reproduction in sugarcane. Optimal reference genes are essential for elucidating the expression pattern of a given gene by quantitative real-time PCR (qRT-PCR). METHOD: In this study, based on transcriptome data obtained from sugarcane ovule, eighteen candidate reference genes were identified, cloned, and their expression levels were evaluated across five developmental stages ovule (AC, MMC, Meiosis, Mitosis, and Mature). RESULTS: Our results indicated that FAB2 and MOR1 were the most stably expressed genes during sugarcane female gametophyte development. Moreover, two genes, cell cycle-related genes REC8 and CDK, were selected, and their feasibility was validated. This study provides important insights into the female gametophyte development of sugarcane and reports novel reference genes for gene expression research on sugarcane sexual reproduction.

Ultrasensitive Exosome Detection by Modularized SERS Labeling for Postoperative Recurrence Surveillance.

Exosome-based liquid biopsy holds great potential in monitoring tumor progression. Current exosome detection biosensors rely on signal amplification strategies to improve sensitivity; however, these strategies pay little attention to manipulating the number of signal reporters, limiting the rational optimization of the biosensors. Here, we have developed a modularized surface-enhanced Raman spectroscopy (SERS) labeling strategy, where each Raman reporter is coupled with lysine as a signal-lysine module, and thus the number of Raman reporters can be precisely controlled by the modularized solid-phase peptide synthesis. Using this strategy, we screened out an optimum Raman biosensor for ultrasensitive exosome detection, with the limit of detection of 2.4 particles per microliter. This biosensor enables a successful detection of the tumor with an average diameter of approximately 3.55 mm, and thus enables successful surveillance of the postoperative tumor recurrence in mice models and distinguishing cancer patients from healthy subjects. Our work provides a de novo strategy to precisely amplify signals toward a myriad of biosensor-related medical applications.

Analysis of the Bacterial Flora of Sensitive Facial Skin Among Women in Guangzhou.

BACKGROUND: Sensitive skin (SS) is easily irritated by various environmental stimuli, and epidemiological surveys surprisingly find that self-perceived SS is widespread worldwide. OBJECTIVE: To investigate whether SS is linked to changes in the skin bacterial population using 16S rRNA sequencing and bioinformatic analysis. PATIENTS AND METHODS: According to both the Huaxi SS Questionnaire and Lactic Acid Stimulation Test, 60 female volunteers in Guangzhou were classified into normal skin (NS) and SS groups. Skin barrier parameters were assessed by the CK skin tester. The DNA of the bacterial flora on the facial skin surface was extracted and was subjected to 16S rRNA sequencing. RESULTS: The skin hydration was significantly lower in the SS group compared to the NS group (P =0.032). Based on 16S rRNA sequencing and bioinformatic analysis, the number of operational taxonomic units (OTUs) significantly decreased in the SS group (P =0.0235, SS vs NS). The relative abundance of Neisseriaceae in SS group decreased significantly (P <0.05, SS vs NS), while that of Neisseria (within the Neisseriaceae family) increased significantly (P <0.05, SS vs NS). CONCLUSION: SS is accompanied by a decrease in species diversity and richness, which may be relevant to the weakening of the microbial barrier (due to the increase of Neisseria or the decrease of Neisseriaceae). Thus, corresponding treatment for Neisseriaceae may be a new idea in the treatment of SS.

Predictive Factors of Postoperative Peritumoral Brain Edema after Meningioma Resection.

BACKGROUND: Postoperative peritumoral brain edema (PTBE) is the progressively exacerbating cerebral edema following meningiomas resection. OBJECTIVE: The study aims to identify the predictive factors of postoperative PTBE. MATERIALS AND METHODS: A retrospective study was conducted on the 117 cases of patients who underwent meningioma. The histopathological features of the tumors were re-assessed according to WHO 2016 classification. Clinical and pathohistological features were analyzed. RESULTS: Thirteen patients (11.1%) were diagnosed having postoperative PTBE. Preoperative seizure (odds ratio [OR] = 6.125, P = 0.039) and histological prominent nucleoli (OR = 3.943, P = 0.039) were the independent risk factors for postoperative PTBE. Meningiomas with a parietal localization were more likely to develop postoperative PTBE (OR = 3.576, P = 0.054). Brain invasion and large tumor volume did not increase complication rate. Preoperative edema index was significantly higher in brain invasive meningiomas (3.0 ± 2.2 versus 1.8 ± 1.7, P = 0.001). Patients having moderate preoperative PTBE were prone to the complication (21.4% versus 7.9%, P = 0.100). CONCLUSIONS: Preoperative seizure were the predictive factors for postoperative PTBE. Careful venous protection during the operation may be helpful, especially for tumors locating in the parietal lobe. Prominent nucleoli observed in postoperative pathology should warrant surgeons' attention. Comprehensive perioperative management is essential for these patients.

Lingual nerve injury caused by laryngeal mask airway during percutaneous nephrolithotomy: A case report.

BACKGROUND: Lingual nerve injury (LNI) is a rare complication following the use of laryngeal mask airway (LMA). The occurrence of this unexpected complication causes uncomfortable symptoms in patients and worsens their quality of life. We present an unusual case of LNI caused by the use of an LMA in percutaneous nephrolithotomy (PCNL). CASE SUMMARY: A 49-year-old man presented to our hospital with a 3-year history of intermittent left lower back pain. Abdominal computed tomography showed a 25 mm × 20 mm stone in the left renal pelvis. PCNL surgery using LMA was performed to remove the renal stone. The patient reported numbness on the tip of his tongue after the operation, but there were no signs of swelling or trauma. The patient was diagnosed with LNI after other possible causes were ruled out. The symptom of numbness eventually improved after conservative medical therapy for 1 wk. The patient completely recovered 3 wk after surgery. CONCLUSION: This is the first case report describing LNI with the use of LMA in PCNL. In our case, an inappropriate LMA size, intraoperative movement, and a specific surgical position might be potential causes of this rare complication.

g-C3N4: Properties, Pore Modifications, and Photocatalytic Applications.

Graphitic carbon nitride (g-C3N4), as a polymeric semiconductor, is promising for ecological and economical photocatalytic applications because of its suitable electronic structures, together with the low cost, facile preparation, and metal-free feature. By modifying porous g-C3N4, its photoelectric behaviors could be facilitated with transport channels for photogenerated carriers, reactive substances, and abundant active sites for redox reactions, thus further improving photocatalytic performance. There are three types of methods to modify the pore structure of g-C3N4: hard-template method, soft-template method, and template-free method. Among them, the hard-template method may produce uniform and tunable pores, but requires toxic and environmentally hazardous chemicals to remove the template. In comparison, the soft templates could be removed at high temperatures during the preparation process without any additional steps. However, the soft-template method cannot strictly control the size and morphology of the pores, so prepared samples are not as orderly as the hard-template method. The template-free method does not involve any template, and the pore structure can be formed by designing precursors and exfoliation from bulk g-C3N4 (BCN). Without template support, there was no significant improvement in specific surface area (SSA). In this review, we first demonstrate the impact of pore structure on photoelectric performance. We then discuss pore modification methods, emphasizing comparison of their advantages and disadvantages. Each method's changing trend and development direction is also summarized in combination with the commonly used functional modification methods. Furthermore, we introduce the application prospects of porous g-C3N4 in the subsequent studies. Overall, porous g-C3N4 as an excellent photocatalyst has a huge development space in photocatalysis in the future.

ATP binding cassette transporters ABCG1 and ABCG16 affect reproductive development via auxin signalling in Arabidopsis.

Angiosperm reproductive development is a complex event that includes floral organ development, male and female gametophyte formation and interaction between the male and female reproductive organs for successful fertilization. Previous studies have revealed the redundant function of ATP binding cassette subfamily G (ABCG) transporters ABCG1 and ABCG16 in pollen development, but whether they are involved in other reproductive processes is unknown. Here we show that ABCG1 and ABCG16 were not only expressed in anthers and stamen filaments but also enriched in pistil tissues, including the stigma, style, transmitting tract and ovule. We further demonstrated that pistil-expressed ABCG1 and ABCG16 promoted rapid pollen tube growth through their effects on auxin distribution and auxin flow in the pistil. Moreover, disrupted auxin homeostasis in stamen filaments was associated with defective filament elongation. Our work reveals the key functions of ABCG1 and ABCG16 in reproductive development and provides clues for identifying ABCG1 and ABCG16 substrates in Arabidopsis.