A meta-analysis reveals that geographical factors drive the bacterial community variation in Chinese lakes.

The biogeographical distribution of plants and animals has been extensively studied, however, the biogeographical patterns and the factors that influence bacterial communities in lakes over large scales are yet to be fully understood, even though they play critical roles in biogeochemical cycles. Here, bacterial community compositional data, geographic information, and environmental factors were integrated for 326 Chinese lakes based on previously published studies to determine the underlying factors that shape bacterial diversity among Chinese lakes. The composition of bacterial communities significantly varied among the three primary climatic regions of China (Northern China, NC; Southern China, SC; and the Tibetan Plateau, TIP), and across two different lake habitats (waters and sediments). Sediment bacterial communities exhibited significantly higher alpha-diversity and distance-decay relationships compared to water communities. The results indicate that the "scale-dependent patterns" of controlling factors, primarily influenced by geographical factors, become increasingly pronounced as the spatial scale increases. At a national scale, geographical factors exerted a dominant influence on both the water and sediment communities across all lakes, as geographical barriers restrict the dispersal of individuals. At smaller spatial scales, temperature-driven selection effects played a greater role in shaping water bacterial community variation in the NC, SC, and TIP, while geographical factors had a stronger association with sediment bacterial community variation in the lakes of the three regions. This synthesis offers novel insights into the ecological factors that determine the distribution of bacteria in Chinese lakes.

Resilience of hybrid herbivore-plant-pollinator networks.

The concept of network resilience has gained increasing attention in the last few decades owing to its great potential in strengthening and maintaining complex systems. From network-based approaches, researchers have explored resilience of real ecological systems comprising diverse types of interactions, such as mutualism, antagonist, and predation, or mixtures of them. In this paper, we propose a dimension-reduction method for analyzing the resilience of hybrid herbivore-plant-pollinator networks. We qualitatively evaluate the contribution of species toward maintaining resilience of networked systems, as well as the distinct roles played by different categories of species. Our findings demonstrate that the strong contributors to network resilience within each category are more vulnerable to extinction. Notably, among the three types of species in consideration, plants exhibit a higher likelihood of extinction, compared to pollinators and herbivores.

Inhibition of KCTD10 Affects Diabetic Retinopathy Progression by Reducing VEGF and Affecting Angiogenesis.

Aim: We purposed to evaluate the KCTD10 effects of angiogenesis in diabetic retinopathy (DR). Methods: We induced a DR cell model using high glucose (HG) treatment of HRECs and ARPE-19 cells. A DR rat was established by injecting streptozotocin. Small interference RNA targeted KCTD10 (si-KCTD10) was used to mediate KCTD10 inhibition in cell and animal models. The roles of KCTD10 on cell viability, apoptosis, angiogenesis, and related proteins (VEGF and HIF-1α) were observed by RT-qPCR, Western blot, CCK-8 assay, TUNEL staining, tube formation assay, ELISA, and immunohistochemistry assay. Results: KCTD10 expression was upregulated in DR cells and retinal tissue of DR rats. Treatment of the cells with si-KCTD10 increased cell viability and decreased apoptosis and angiogenesis in DR cells. Inhibition of KCTD10 could reduce the expression of VEGF and HIF-1α in DR cells. Furthermore, KCTD10 inhibition reduced VEGF levels in the retinal tissue of DR rats. Conclusion: This work showed that inhibition of KCTD10 relieved angiogenesis in DR.

Tetrahydroxydiboron and Nickel Chloride Cocatalyzed Rapid Radical Cyclization toward Pyrrolizidine and Indolizidine Alkaloids.

A novel tetrahydroxydiboron and nickel chloride cocatalyzed radical cyclization cascade with a broad substrate scope and an ultrashort reaction time was developed. The mechanistic investigation indicated that the reaction might involve a homocleavage of tetrahydroxydiboron and nickel hydride intermediates. This approach enables the simple and efficient synthesis of a series of heteropolycycles.

Computational design of a new layered superconductor LaOTlF2.

A new layered compound LaOTlF2 is designed and investigated using first-principles calculations in this work. The parent compound is an insulator with an indirect band gap of 3.88 eV. Electron-doping of the parent compound makes the material metallic. In the meantime, several lattice vibrational modes couple strongly to the conduction band, leading to a large electron-phonon coupling constant and conventional superconductivity. The highest superconducting transition temperature Tc is predicted to be approximately 8.6 K with λ about 1.25 in the optimally doped LaO0.95F0.05TlF2, where λ is calculated using the Wannier interpolation technique.

Copper-Catalyzed Diboron-Mediated cis-Semi-Hydrogenation of Alkynes under Facile Conditions.

Cis-alkenes are ubiquitous in biological molecules, which makes it greatly significant to develop efficient methods toward construction of cis-olefins. Herein, we reported a facile semi-hydrogenation of alkynes to cis-alkenes in an efficient way with cuprous bromide/tributylphosphine as the catalyst and bis(pinacolato)diboron/methanol as the hydrogen donor. The method features convenient and facile reaction conditions, wide substrate scope, high yields, and high stereoselectivity.

Novel Small Molecule Fibroblast Growth Factor 23 Inhibitors Increase Serum Phosphate and Improve Skeletal Abnormalities in Hyp Mice.

Excess fibroblast growth factor (FGF) 23 causes hereditary hypophosphatemic rickets, such as X-linked hypophosphatemia (XLH) and tumor-induced osteomalacia (TIO). A small molecule that specifically binds to FGF23 to prevent activation of the fibroblast growth factor receptor/α-Klotho complex has potential advantages over the currently approved systemically administered FGF23 blocking antibody. Using structure-based drug design, we previously identified ZINC13407541 (N-[[2-(2-phenylethenyl)cyclopenten-1-yl]methylidene]hydroxylamine) as a small molecule antagonist for FGF23. Additional structure-activity studies developed a series of ZINC13407541 analogs with enhanced drug-like properties. In this study, we tested in a preclinical Hyp mouse homolog of XLH a direct connect analog [(E)-2-(4-(tert-butyl)phenyl)cyclopent-1-ene-1-carbaldehyde oxime] (8n), which exhibited the greatest stability in microsomal assays, and [(E)-2-((E)-4-methylstyryl)benzaldehyde oxime] (13a), which exhibited increased in vitro potency. Using cryo-electron microscopy structure and computational docking, we identified a key binding residue (Q156) of the FGF23 antagonists, ZINC13407541, and its analogs (8n and 13a) in the N-terminal domain of FGF23 protein. Site-directed mutagenesis and bimolecular fluorescence complementation-fluorescence resonance energy transfer assay confirmed the binding site of these three antagonists. We found that pharmacological inhibition of FGF23 with either of these compounds blocked FGF23 signaling and increased serum phosphate and 1,25-dihydroxyvitamin D [1,25(OH)2D] concentrations in Hyp mice. Long-term parenteral treatment with 8n or 13a also enhanced linear bone growth, increased mineralization of bone, and narrowed the growth plate in Hyp mice. The more potent 13a compound had greater therapeutic effects in Hyp mice. Further optimization of these FGF23 inhibitors may lead to versatile drugs to treat excess FGF23-mediated disorders. SIGNIFICANCE STATEMENT: This study used structure-based drug design and medicinal chemistry approaches to identify and optimize small molecules with different stability and potency, which antagonize excessive actions of fibroblast growth factor 23 (FGF23) in hereditary hypophosphatemic rickets. The findings confirmed that these antagonists bind to the N-terminus of FGF23 to inhibit its binding to and activation of the fibroblast growth factor receptors/α-Klotho signaling complex. Administration of these lead compounds improved phosphate homeostasis and abnormal skeletal phenotypes in a preclinical Hyp mouse model.

Direct Synthesis of N-Difluoromethyl-2-pyridones from Pyridines.

A novel method for the synthesis of N-difluoromethyl-2-pyridones was described. This protocol enables the synthesis of N-difluoromethyl-2-pyridones from readily available pyridines using mild reaction conditions that are compatible with a wide range of functional groups. The preliminary mechanistic study revealed that N-difluoromethylpyridinium salts were the key intermediates to complete this conversion.

Photoinduced Release of Volatile Organic Compounds from Fatty Alcohols at the Air-Water Interface: The Role of Singlet Oxygen Photosensitized by a Carbonyl Group.

Photoinduced interfacial release of volatile organic compounds (VOCs) from surfactants receives emerging concerns. Here, we investigate the photoreaction of 1-nonanol (NOL) as a model surfactant at the air-water interface, especially for the important role of 1O2 in the formation of VOCs. The production of VOCs is real-time quantitated. The results indicate that the oxygen content apparently affects the total yields of VOCs during the photoreaction of interfacial NOL. The photoactivity of NOL is about 8 times higher under air than that under nitrogen, which is mainly attributed to the generation of 1O2. Additionally, the production of VOCs increased by about 4 times with the existence of the air-water interface. Quenching experiments of 1O2 also illustrate the contribution of 1O2 to VOC formation, which could reach more than 95% during photoirradiation of NOL. Furthermore, density functional theory calculations show that 1O2 generated via energy transfer of photosensitizers can abstract two hydrogen atoms from a fatty alcohol molecule. The energy barrier of this reaction is 72.3 kJ/mol, and its reaction rate coefficient is about 2.742 s-1 M-1. 1O2 significantly promotes photoinduced oxidation of fatty alcohols and VOC formation through hydrogen abstraction, which provides a new insight into the interfacial photoreaction.

Novel laparoscopic surgery for the repair of cesarean scar defect without processing scar resection.

BACKGROUND: Cesarean scar defect (CSD), especially CSD with residual myometrium less than 3 mm is reported to be the highest risk agent associated with uterine rupture for subsequent pregnancy. Currently, laparoscopic resection and suture was the mainstay therapy method for CSD with a residual myometrium less than 3 mm in women with a desire to conceive. Besides, the women have CSD related symptoms, especially postmenstrual bleeding, should be recommended for CSD treatment. This study is to investigate the efficiency of this novel laparoscopic surgery for the repair of cesarean scar defect (CSD) without scar resection for residual myometrium thickening. METHOD: This retrospective clinical study enrolled 76 women diagnosed with CSD who had a residual myometrium thickness less than 3 mm and also had a desire to conceive, had undergone laparoscopic surgery for the repair of CSD in the time period March 2016 to March 2018. Two study cohorts were created among the 76 patients: 40 patients had undergone the novel laparoscopic repair of CSD without processing scar resection (Group A), whereas 36 patients had undergone the traditional laparoscopic resection and suture of CSD (Group B). RESULTS: Residual myometrium thickening occurred among all the 76 patients and the average residual myometrium thickness was increased to almost 6 mm, presenting no between-group difference. In Group A, all the CSD-related postmenstrual bleeding was resolved or improved, but one patient in Group B has no obvious change to postmenstrual bleeding. After CSD repair, 20 patients got pregnant naturally in Group A, and there was no cesarean scar pregnancy and uterine rupture. While, there were 9 cases of natural pregnancy in Group B. No uterine rupture occurred among these 9 pregnant women of Group B, but 1 case of pregnancy was terminated due to cesarean scar pregnancy. CONCLUSION: Laparoscopic repair without processing scar resection seems to be a feasible, safe and simple operative approach for CSD treatment, which can thicken residual myometrium and improve postmenstrual bleeding.

lncRNA SNHG16 promotes glioma tumorigenicity through miR-373/EGFR axis by activating PI3K/AKT pathway.

Glioma is one of the most common and aggressive malignant primary brain tumor with invariably poor 5-year survival rates. Because of the high recurrence rate and mortality rate, effective therapies for glioma are still weak. Recently, several studies has been proved that long non-coding RNAs (lncRNAs) have been identified to play regulatory mediators in the tumorigenesis of glioma. Nevertheless, the role of lncRNAs and their downstream transcripts are still elusive in the progression of glioma. Small nucleolar RNA host gene 16 (SNHG16), a newly identified lncRNA, has been verified to be up-regulated in human malignant carcinomas. In the present study, we confirmed that lncRNA SNHG16 was highly expressed in glioma and may exert oncogenic function as a competing endogenous RNA (ceRNA) to regulate EGFR by sponging of miR-373-3p through activating PI3K/AKT pathway, which providing a new insight of the regulatory network of lncRNA SNHG16 in the development of glioma.

2D Molecular Crystal Bilayer p-n Junctions: A General Route toward High-Performance and Well-Balanced Ambipolar Organic Field-Effect Transistors.

Ambipolar organic field-effect transistors (OFETs) are vital for the construction of high-performance all-organic digital circuits. The bilayer p-n junction structure, which is composed of separate layers of p- and n-type organic semiconductors, is considered a promising way to realize well-balanced ambipolar charge transport. However, this approach suffers from severely reduced mobility due to the rough interface between the polycrystalline thin films of p- and n-type organic semiconductors. Herein, 2D molecular crystal (2DMC) bilayer p-n junctions are proposed to construct high-performance and well-balanced ambipolar OFETs. The molecular-scale thickness of the 2DMC ensures high injection efficiency and the atomically flat surface of the 2DMC leads to high-quality p- and n-layer interfaces. Moreover, by controlling the layer numbers of the p- and n-type 2DMCs, the electron and hole mobilities are tuned and well-balanced ambipolar transport is accomplished. The hole and electron mobilities reach up to 0.87 and 0.82 cm2 V-1 s-1 , respectively, which are the highest values among organic single-crystalline double-channel OFETs measured in ambient air. This work provides a general route to construct high-performance and well-balanced ambipolar OFETs based on available unipolar materials.

Copper-Catalyzed Oxydifluoroalkylation of Hydroxyl-Containing Alkenes.

An efficient oxydifluoroalkylation of hydroxyl-containing alkenes using a copper catalytic system has been developed. This reaction proceeded through a one-pot process of difluoroalkylation followed by nucleophilic attack of the appended hydroxyl group. This strategy has the advantages of a low-cost catalyst and broad substrate scope, which provides a facile access to various fluoroalkylated tetrahydrofurans and tetrahydropyrans.

An Effective Assisted Method Using Hysteroscopy Transmittance Test and a Foley Catheter to Repair Previous Cesarean Scar Defect by Laparoscopy.

STUDY OBJECTIVE: To introduce an effective assisted method using the hysteroscopy transmittance test and a Foley catheter to repair previous cesarean scar defect (PCSD) by laparoscopy. DESIGN: A step-by-step explanation of the surgery using video. SETTING: A university hospital. PATIENTS: A young woman with abnormal uterine bleeding. INTERVENTIONS: First, we inspected the pelvic cavity and detached the adhesion, opened the uterovesical peritoneal reflection, and pushed down the bladder. Then, the hysteroscopy transmittance test was used to confirm the site and the size of the PCSD. Next, a Foley catheter was inserted into the diverticulum through the cervical canal, and then we removed the diverticulum along the outer edge [1-4]. The myometrium and the serosal layer were sutured continuously with absorbable sutures. At this point, a second hysteroscopy transmittance test was performed to verify the repair effect. Finally, we placed antiadhesive film. MEASUREMENTS AND MAIN RESULTS: The location, size, and boundary of the PCSD can be exactly marked by this method. The operative time was 68 minutes, blood loss was 20mL, and no complications occurred. CONCLUSION: This surgical method has the following benefits: the resection of the diverticulum is complete, and the suture is exact; it is suitable for patients with a thin diverticulum wall, large diverticulum cavity, and a long duration of bleeding after menstruation; the hysteroscopy transmittance test was used to confirm the site of the PCSD and verify the repair effect; and the Foley catheter can marker the resection site, prevent gas leakage, and stop bleeding by local compression.

Copper-mediated regioselective hydrodifluoroalkylation of alkynes.

A highly regioselective copper-mediated hydrodifluoroalkylation of alkynes with ethyl bromodifluoroacetate or bromodifluoroacetamides has been developed. This strategy provides straightforward access to a variety of difluoroalkylated alkenes under mild reaction conditions with low-cost cuprous bromide and metabisulfite as reduction agents. A wide range of alkynes are applicable under these reaction conditions. The excellent functional-group compatibility and good regio- and stereoselectivities are the notable features of this transformation.

In Situ Nanoreactors: Controllable Photoluminescent Carbon-Rich Polymer Nanodots Derived from Fatty Acid under Photoirradiation.

Amphiphilic nanoreactors have been recently used to fabricate photoluminescent carbon-rich polymer nanodots (PCPNs). However, the applications of PCPNs have been limited by their requirements for high temperature and toxic organic solvents or catalysts and the difficult control of their luminescent properties. Herein, a novel and facile strategy is reported for the synthesis of controllable PCPNs. This strategy involves the use of in situ vesicular nanoreactors under mild photoirradiation with fatty acid as the precursor. The conjugation degree of the uniformly sized PCPNs can be increased by extending photoreaction time, thus enabling the tuning of the optical properties of PCPNs. The PCPNs, which feature controllable and outstanding luminescent properties, low cytotoxicity, and biocompatibility, are successfully applied in bioimaging and as fluorescent ink. The present strategy is an attractive and facile platform for the preparation of carbon-rich nanomaterials with controllable photoluminescence.

Engineering Brevibacterium flavum for the production of renewable bioenergy: C4-C5 advanced alcohols.

Biosynthesis of advanced biofuels by engineered non-natural microorganisms has been proposed to be the most promising approach for the replacement of dwindling fossil fuel resources. Brevibacterium flavum (Bf) is a model brevibacterium aerobe which lacks basic and applied research that could enable this species to produce biofuels. There are no reports regarding engineering this microorganism to produce advanced alcohols before. Here, for the first time, we developed the bacterium as a novel biosynthetic platform for advanced alcohols production via the mutagenesis and engineering to produce 2-ketoacids derived alcohols. In order to enhance the strain's capability of producing advanced alcohols, we preferentially improved intrinsic metabolism ability of the strain to obtain improved expression host (IEH) via generating mutagenesis libraries by whole cell mutagenesis (WCM). The IEH was determined via screening out the mutant strain with the highest production of branched-chain organic acids (BCOA) using high throughput screening method.. Subsequently, a novel vector system for Bf was established, and the corresponding biosynthetic pathway of directing carbon flux into the target advanced alcohols was recruited to make the bacterium possess the capability of producing advanced alcohols and further enhance the production using the IEH. Specifically, we generated bioengineered strains that were able to synthesize up to the highest 5362 and 4976 mg/L isobutanol, 1945 and 1747 mg/L 2-methyl-1-butanol (2 MB), and 785.34 and 781 mg/L 3-methyl-1-butanol (3 MB) from pure glucose and duckweed substrates, respectively. Our findings confirmed the feasibility and potential of using Bf as a novel biosynthetic platform to generate advanced biofuels with glucose and inexpensive renewable feedstock-duckweed as a fermentation substrate. Biotechnol. Bioeng. 2017;114: 1946-1958. © 2017 Wiley Periodicals, Inc.

Purification and bioactivities of phycocyanin.

Phycocyanin is an important light-harvesting pigment antenna protein in cyanobacteria, rhodophyta, cryptophyta, and glaucophyta, with a variety of bioactivities. The introduction of purification and bioactivities of phycocyanin contributes to a significant improvement in developing it into final processed products. In fact, the knowledge of phycocyanin has experienced a rapid increase in the past 20 years, and has promoted the relevant technological revolution with a decisive contribution to final application. The purpose of this review is to critically introduce the present knowledge of purification and bioactivities of phycocyanin, and to illustrate main problems and prospects.

Synthesis of 4-benzylpyridines via Pd-catalyzed CH3-arylation of 4-picoline.

A highly efficient synthesis of 4-benzylpyridines was developed via Pd-catalyzed C(sp3)-H arylation between 4-picoline and aryl halides. It was found that the best yields were achieved with a simple Pd(PPh3)4 catalyst and Cs2CO3 as the base. Compared with the known methods, our reaction does not require the use of a strong organometallic reagent as the base.

Photocatalytic/Cu-Promoted C-H Activations: Visible-light-Induced ortho-Selective Perfluoroalkylation of Benzamides.

A visible-light-induced and copper-promoted perfluoroalkylation of benzamides was successfully developed under the assistance of an 8-aminoquinoline directing group. It provides a straightforward method for the synthesis of ortho-perfluoroalkyl-substituted benzoic acid derivatives. The reaction employs a cheap organic dye eosin Y as the photoredox catalyst and is run under the irradiation of a 26 W fluorescent LED light bulb.