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.

Area-Selective Depolymerization of Hydroxycinnamates Visualized by Raman Imaging in Miscanthus sinensis cv. Cell Wall.

Lignin-carbohydrate complexes (LCCs) are regarded as a barrier for lignocellulosic biomass refinery. Here, confocal Raman microspectroscopy has been used to visualize the dissolution of hydroxycinnamates (HCMs) incorporated into LCCs by ether and ester bonds for energy crops Miscanthus sinensis cv. during successive NaOH (2.5% w/w) treatment. Raman spectral analysis indicated that mild NaOH treatment resulted in a higher proportion of HCM depolymerization in highly lignified middle lamella areas (>66.0%) than carbohydrate-abundant secondary walls. Furthermore, Raman imaging revealed preferential depolymerization of lignin from the sclerenchyma fiber (Sf) and parenchyma (Par) secondary wall with an increment of treatment time from 0 to 25 min, while middle lamella areas of Sf and Par were less affected where the depolymerization of HCMs was closely related with that of lignin (coefficient factors > 0.96). A better understanding of the depolymerization behavior for HCMs accompanied by lignin depolymerization was important to break LCC bonds in herbaceous biomass efficiently.

Fertilizing-induced alterations of microbial functional profiles in soil nitrogen cycling closely associate with crop yield.

Fertilization and rhizosphere selection are key regulators for soil nitrogen (N) cycling and microbiome. Thus, clarifying how the overall N cycling processes and soil microbiome respond to these factors is a prerequisite for understanding the consequences of high inputs of fertilizers, enhancing crop yields, and formulating reasonable nitrogen management strategies under agricultural intensification scenarios. To do this, we applied shotgun metagenomics sequencing to reconstruct N cycling pathways on the basis of abundance and distribution of related gene families, as well as explored the microbial diversity and interaction via high throughput sequencing based on a two-decade fertilization experiment in Loess Plateau of China semiarid area. We found that bacteria and fungi respond divergent to fertilization regimes and rhizosphere selection, in terms of community diversity, niche breadth, and microbial co-occurrence networks. Moreover, organic fertilization decreased the complexity of bacterial networks but increased the complexity and stability of fungal networks. Most importantly, rhizosphere selection exerted more strongly influences on the soil overall nitrogen cycling than the application of fertilizers, accompanied by the increase in the abundance of nifH, NIT-6, and narI genes and the decrease in the abundance of amoC, norC, and gdhA genes in the rhizosphere soil. Furthermore, keystone families screening from soil microbiome (e.g., Sphingomonadaceae, Sporichthyaceae, and Mortierellaceae), which were affected by the edaphic variables, contributed greatly to crop yield. Collectively, our findings emphasize the pivotal roles of rhizosphere selection interacting with fertilization regimes in sustaining soil nitrogen cycling processes in response to decades-long fertilization, as well as the potential importance of keystone taxa in maintaining crop yield. These findings significantly facilitate our understanding of nitrogen cycling in diverse agricultural soils and lay a foundation for manipulating specific microorganisms to regulate N cycling and promote agroecosystem sustainability.

Weak environmental adaptation of rare phylotypes sustaining soil multi-element cycles in response to decades-long fertilization.

Deciphering the ecological role of soil communities in the maintenance of multiple ecosystem functions is pivotal for the conservation and sustainability of soil biodiversity. However, few studies have investigated niche differentiation of abundant and rare microbiota, as well as their contributions to multiple soil elemental cycles, particularly in agroecosystems that have received decades of intense fertilization. Here, we characterized the environmental thresholds and phylogenetic signals for the environmental adaptation of both abundant and rare microbial subcommunities via amplicon sequencing and metagenomic sequencing and explored their importance in sustaining soil multiple nutrient cycling in agricultural fields that were fertilized for two decades. The results showed that rare taxa exhibited narrower niche breadths and weaker phylogenetic signals than abundant species. The assembly of abundant subcommunity was shaped predominantly by dispersal limitation (explained 71.1 % of the variation in bacteria) and undominated processes (explained 75 % of the variation in fungi), whereas the assembly of rare subcommunity was dominated by homogeneous selection process (explained 100 % of the variation in bacteria and 60 % of the variation in fungi). Soil ammonia nitrogen was the leading factor mediating the balance between stochastic and deterministic processes in both abundant (R2 = 0.15, P < 0.001) and rare (R2 = 0.08, P < 0.001) bacterial communities. Notably, the rare biosphere largely contributed to key soil processes such as carbon (R2bacteria = 0.03, P < 0.05; R2fungi = 0.05, P < 0.05) and nitrogen (R2bacteria = 0.03, P < 0.05; R2fungi = 0.17, P < 0.001) cycling. Collectively, these findings facilitate our understanding of the maintenance of rhizosphere bacterial and fungal diversity in response to agricultural fertilization and highlight the key role of rare taxa in sustaining agricultural ecosystem functions.

Rapid Identification for the Pterocarpus Bracelet by Three-Step Infrared Spectrum Method.

In order to explore a rapid identification method for the anti-counterfeit of commercial high value collections, a three-step infrared spectrum method was used for the pterocarpus collection identification to confirm whether a commercial pterocarpus bracelet (PB) was made from the precious species of Pterocarpus santalinus (P. santalinus). In the first step, undertaken by Fourier transform infrared spectroscopy (FTIR) spectrum, the absorption peaks intensity of PB was slightly higher than that of P. santalinus only at 1594 cm-1, 1205 cm-1, 1155 cm-1 and 836 cm-1. In the next step of second derivative IR spectra (SDIR), the FTIR features of the tested samples were further amplified, and the peaks at 1600 cm-1, 1171 cm-1 and 1152 cm-1 become clearly defined in PB. Finally, by means of two-dimensional correlation infrared (2DIR) spectrum, it revealed that the response of holocellulose to thermal perturbation was stronger in P. santalinus than that in PB mainly at 977 cm-1, 1008 cm-1, 1100 cm-1, 1057 cm-1, 1190 cm-1 and 1214 cm-1, while the aromatic functional groups of PB were much more sensitive to the thermal perturbation than those of P. santalinus mainly at 1456 cm-1, 1467 cm-1, 1518 cm-1, 1558 cm-1, 1576 cm-1 and 1605 cm-1. In addition, fluorescence microscopy was used to verify the effectiveness of the above method for wood identification and the results showed good consistency. This study demonstrated that the three-step IR method could provide a rapid and effective way for the anti-counterfeit of pterocarpus collections.

Unravelling the Complete Raman Response of Graphene Nanoribbons Discerning the Signature of Edge Passivation.

Controlling the edge morphology and terminations of graphene nanoribbons (GNR) allows tailoring their electronic properties and boosts their application potential. One way of making such structures is encapsulating them inside single-walled carbon nanotubes. Despite the versatility of Raman spectroscopy to resolve strong spectral signals of these systems, discerning the response of long nanoribbons from that of any residual precursor remaining outside after synthesis has been so far elusive. Here, the terrylene dye is used as precursor to make long and ultra-narrow armchair-edged GNR inside nanotubes. The alignment and characteristic length of terrylene encapsulated parallel to the tube's axis facilitates the ribbon formation via polymerization, with high stability up to 750 °C when the hybrid system is kept in high vacuum. A high temperature annealing is used to remove the terrylene external molecules and a subtraction model based on the determination of a scaling factor related to the G-band response of the system is developed. This not only represents a critical step forward toward the analysis of the nanoribbon-nanotube system, but it is a study that enables unraveling the Raman signatures of the individual CH-modes (the signature of edge passivation) for GNR for the first time with unprecedented detail.

[Phenotypic and genetic analysis of a boy with inv dup del(8p)].

OBJECTIVE: To delineate the nature and origin of a chromosomal aberration detected in a boy with mental retardation. METHODS: The proband and his parents were subjected to routine G-banded chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) analysis. RESULTS: The karyotype of the proband was determined as 46, XX, add(8)(p23). No karyotypic abnormality was detected in either of his parents. SNP-array has identified a 34.9 Mb duplication at 8p23.1q11.1 and a 6.78 Mb microdeletion at 8p23.1pter in the proband. No copy number variation was detected in either parent. CONCLUSION: The child was diagnosed with 8p inverted duplication deletion syndrome, which might be induced by non-allelic homologous recombination between olfactory genes in the 8p23.1 region.

Isotopic Labelling of Confined Carbyne.

Carbyne is a one-dimensional allotrope of carbon consisting of a linear chain of carbon atoms bonded to each other with exceptional strength. Its outstanding mechanical, optical, and electronic properties have been theoretically predicted, but its stability has only been achieved when grown encapsulated in the hollow core of carbon nanotubes. One of the advantages of this confinement is that its properties can be controlled by the chain's length and surrounding environment. We investigated an alternative way of gaining control of its properties is using isotope labelling as tuning mechanism. The optimized liquid precursor was first chosen among several options, which can greatly enhance the yield of the confined carbyne. Then isotopic labelled liquid precursor was encapsulated for further synthesis of isotopic labelled confined carbyne. This allowed us to obtain pioneering results on isotope engineered carbyne with around 11.9 % of 13 C-labelling using 13 C-methanol as precursor.

Oxidation stability of confined linear carbon chains, carbon nanotubes, and graphene nanoribbons as 1D nanocarbons.

Three typical one-dimensional (1D)/quasi-1D nanocarbons, linear carbon chains, carbon nanotubes, and graphene nanoribbons have been proved to grow inside single-walled carbon nanotubes. This gives rise to three types of hybrid materials whose behaviour and properties compared among each other are far from being understood. After proving the successful synthesis of these nanostructured materials in recently published work, we have now been able to study their oxidation stability systematically by using resonance Raman spectroscopy. Surprisingly, the linear carbon chains, which have been theoretically predicted to be very unstable, are actually thermally stable up to 500 °C, assisted by the protection of the carbon nanotube hosts. Besides, longer linear carbon chains inside narrower CNTs are more stable than the shorter ones inside larger tubes, suggesting that the thermal stability not only depends on the length of linear carbon chains alone, but it is correlated with the confinement of the host tubes in a more complicated manner. In addition, graphene nanoribbons overall appear to be the most stable confined structures. On the other hand, peculiarities like the higher stability of the (6,5) CNT compared to that of its (6,4) counterpart allow this study to provide a solid platform for further studies on the application of these 1D nanocarbons (including true 1D linear carbon chains) under ambient conditions.

Picosecond ultrasonic study of surface acoustic waves on periodically patterned layered nanostructures.

We have used the ultrafast pump-probe technique known as picosecond ultrasonics to generate and detect surface acoustic waves on a structure consisting of nanoscale Al lines on SiO2 on Si. We report results from ten samples with varying pitch (1000-140 nm) and SiO2 film thickness (112 nm or 60 nm), and compare our results to an isotropic elastic calculation and a coarse-grained molecular dynamics simulation. In all cases we are able to detect and identify a Rayleigh-like surface acoustic wave with wavelength equal to the pitch of the lines and frequency in the range of 5-24 GHz. In some samples, we are able to detect additional, higher frequency surface acoustic waves or independent modes of the Al lines with frequencies close to 50 GHz. We also describe the effects of probe beam polarization on the measurement's sensitivity to the different surface modes.

Apigenin Attenuates Adriamycin-Induced Cardiomyocyte Apoptosis via the PI3K/AKT/mTOR Pathway.

Treatment with Adriamycin (ADR) is one of the major causes of chemotherapy-induced cardiotoxicity and therefore is the principal limiting factor in the effectiveness of chemotherapy for cancer patients. Apigenin (API) has been shown to play a cardioprotective role. The present study examined the effect of API on ADR-induced cardiotoxicity in mice. Sixty male Kunming mice were randomly divided into 4 groups: a control group, ADR model group, low-dose API treatment group (125 mg·kg-1), and high-dose API treatment group (250 mg·kg-1). Blood samples were taken to evaluate a spectrum of myocardial enzymes. Cardiomyocyte apoptosis was measured using a TUNEL assay, and cardiomyocyte autophagy was observed using electron microscopy. Moreover, apoptosis-related proteins, such as Bax and Bcl-2, autophagy-related proteins, including Beclin1 and LC3B, and PI3K/AKT/mTOR pathway-related proteins were examined with western blot. Our results demonstrate that ADR caused an increase in the serum levels of cardiac injury markers and enhanced cardiomyocyte apoptosis and autophagy. API administration prevented the effects associated with ADR-induced cardiotoxicity in mice and inhibited ADR-induced apoptosis and autophagy. API also promoted PI3K/AKT/mTOR pathway activity in ADR-treated mice. In conclusion, API may have a protective effect against ADR-induced cardiotoxicity by inhibiting apoptosis and autophagy via activation of the PI3K/AKT/mTOR pathway.

CO2 -Assisted Fabrication of Two-Dimensional Amorphous Molybdenum Oxide Nanosheets for Enhanced Plasmon Resonances.

As a remarkable class of plasmonic materials, two dimensional (2D) semiconductor compounds have attracted attention owing to their controlled manipulation of plasmon resonances in the visible light spectrum, which outperforms conventional noble metals. However, tuning of plasmonic resonances for 2D semiconductors remains challenging. Herein, we design a novel method to obtain amorphous molybdenum oxide (MoO3 ) nanosheets, in which it combines the oxidation of MoS2 and subsequent supercritical CO2 -treatment, which is a crucial step for the achievement of amorphous structure of MoO3 . Upon illumination, hydrogen-doped MoO3 exhibits tuned surface plasmon resonances in the visible and near-IR regions. Moreover, a unique behavior of the amorphous MoO3 nanosheets has been found in an optical biosensing system; there is an optimum plasmon resonance after incubation with different BSA concentrations, suggesting a tunable plasmonic device in the near future.

[Substitution of antelope horn in Danqi Piantan capsule with artificial bezoar in vitro].

The in vitro cell culture experiment was conducted to study the effect of Danqi Piantan capsule (DPC) and DPC dislodge the antelope horn with artificial bezoar double (DPCBD) on nerve regeneration and blood vessel regeneration and preliminarily investigate the possibility of substituting antelope horn in DPC with artificial bezoar. In this experiment, rats were randomly divided into 5 groups: the blank serum control group, the model group, DPC groups (0.306 g x kg(-1) x d(-1), the same below), DPC remove of antelope horn (DPCRA) groups and DPCBD groups. Brain microvascular endothelial cells cultured in vitro (BMEC), astrocytes and neural stem cells (NSC) were co-cultured to simulate neurovascular unit, label neurons with microtubule associated protein III (ß-tubulin III) antibody and lable astrocytes with glial fibrillary acidicprotein (GFAP). ELISA was used for the detection of the content of BMEC lactate dehydrogenase instrument method (LDH), the inverted phase contrastmicroscope was adopted to observe the formation of BMEC tube like structure, the number of leukocytes and leukocytes adherent to BMEC were counted under the microscope, the expression levels of ß-tubulin III and the ratio of GFAP positive cells was detected with inimmunofluorescence, and RT-PCR method was used to detect NGF, BDNF, VEGF and VEGFr-2 mRNA. According to the result, compared with the model group, both DPC and DPCBD can reduce LDH leakage, promote the formation of BMEC tube like structure, inhibit leukocytes and their adhesion to BMEC, increase the ß-tubulin III positive cell differentiation proportion (P < 0. 01), reduce the proportion of GFAP positive cells (P < 0.01), increase the expressions of co-cultured NGF, VEGF, BDNF and VEGFr-2 mRNA to a certain extent, with the most significant difference on NGF and VEGF mRNA expressions (P < 0.05) and the same efficacy in both groups. DPCRA groups showed less impact on all indexes than that of DPCBD and DPC groups. The same efficacy of DPCBD and DPC on nerve regeneration and angiogenesis suggested that antelope horn in DPC can be substituted by artificial bezoar.

[Preliminary study on substitution of Antelope Horn in Danqi Piantan capsule with artificial bezoar].

To study the protective effect of Danqi Piantan capsule ( DPC) and its antelope horn substitution (DPCAS) on the cerebral ischemia, in order to preliminary study the possibility of replacing antelope horn with artificial bezoar. In this study, the left middle cerebral artery occlusion (MCAO) was adopted. Totally 150 SD rats were randomly divided into 5 groups: the sham operation group, the model group, the Danqi Piantan capsule (DPC) group (0.246 g x kg(-1) x d(-1)), the Danqi Piantan capsule without antelope horn (DPCRA) group (0.246 g x kg(-1) x d(-1)), the Danqi Piantan capsule without antelope horn and with double artificial bezoar (DPCDB) group (0.246 g x kg(-1) x d(-1)). The MCAO model was prepared 1 h later after the administration on the 5th day. At 24 h after the operation, the inner canthus blood was collected to determine the serum superoxide dismutase (SOD) activity and the endothelin (ET) content. At 72 h after the operation, the cerebral infarct size and the cerebral index were determined by TTC-staining. The fluorescent quantitative PCR method was used to detect brain Bcl-2, Caspase-3, IL-1ß, P-selectin, E-selectin, ICAM-1 mRNA expressions. The mmunohistochemical method was used to detect ICAM-1, IL-1ß, TNF-α, IL-6 expressions in ischemic penumbra. According to the results, compared with the model group, DPCDB and DPC groups showed almost consistent results, indicating both of the two group can significantly improved cerebral infarction index and cerebral index (P < 0.05), increase the serum SOD activity (P < 0.05), decrease the serum ET level and Caspase-3 expression, IL-1ß, P-selectin, E-selectin, ICAM-1 mRNA expressions in brain tissues (P < 0.05) and expressions of ICAM-1, IL-1,6, TNF-α, IL-6 positive cells in ischemic penumbra (P < 0.05) and increase the Bcl-2 expression (P < 0.05). The DPCRA group showed much lower impacts on indexes than DPCDB and DPC groups. This suggests that DPCDB and DPC reveal similar efficacies and antelope horn in Danqi Piantan capsule can be substitutes by artificial bezoar.

Effects of B7-H3 on the inflammatory response and expression of MMP-9 in mice with pneumococcal meningitis.

B7-H3, a new member of the B7 superfamily, plays a key role in the regulation of T cell-mediated immune responses. Our previous work showed that B7-H3 strongly augmented both LPS- and bacterial lipoprotein-induced NF-κB activation and inflammatory response, and soluble B7-H3 was elevated in CSF and plasma of patients with bacterial meningitis. MMP-9 has been implicated in blood-brain barrier disruption, inflammation, and vasculitis during the pathogenesis of bacterial meningitis. In this study, we report that in a murine model of pneumococcal meningitis, B7-H3 treatment enhances inflammatory response in the meninges, upregulates MMP-9 expression in cerebral parenchyma, and deteriorates clinical disease status indicated by weight loss and impaired movement ability. In vitro results showed that B7-H3 augmented MMP-9 secretion from Streptococcus pneumoniae-stimulated microglia cells. Thus, our data indicate that B7-H3 contributes to the development of pneumococcal meningitis by exaggerating inflammatory responses and upregulating MMP-9 activity in CNS, which ultimately lead to neuronal injury.

Five-year follow-up study of a kidney-tonifying herbal Fufang for prevention of postmenopausal osteoporosis and fragility fractures.

To observe the kidney-tonifying herbal Fufangs with phytoestrogenic epimedium for prevention of postmenopausal osteoporosis with both bone mineral density (BMD) and fracture as study endpoints, a 5-year multicenter follow-up study in 194 postmenopausal women (47-70 years old) was conducted in which the subjects were given oral administration of herbal Fufang (10 g/day, twice per day, n = 101) or placebo (n = 93). Both groups were supplemented daily with calcium (600 mg) and vitamin D (400 IU). BMD at distal radius, potential adverse events, and fracture incidence were evaluated at baseline and at 6, 12, 24, 36, 48, and 60 months. At the end of 5 years, 155 subjects had completed the study, with better adherence in the treatment group (13% dropouts, n = 88 at year 5) as compared with the control group (28% dropouts, n = 67 at year 5) (P < 0.05). No notable adverse events were observed in either group. In the treatment group BMD increased significantly from baseline (0.211 ± 0.022 g/cm(2)) to the end of the study (0.284 ± 0.015 g/cm(2)), whereas the control group decreased significantly from baseline (0.212 ± 0.023 g/cm(2)) to 5 years later (0.187 ± 0.022 g/cm(2)) (P < 0.05). The fracture incidence was 2.4 fold lower in the treatment group than in the control group, with a relative risk of 0.57 for the treatment group (95% CI, 0.43-0.70, P < 0.05). In conclusion, in addition to the beneficial effects of oral herbal Fufang on prevention of postmenopausal bone loss, this 5-year multi-center clinical study demonstrated for the first time its potential for reduction in fragility fracture incidence.

Mechanical peeling of free-standing single-walled carbon-nanotube bundles.

An in situ electron microscopy study is presented of adhesion interactions between single-walled carbon nanotubes (SWNTs) by mechanically peeling thin free-standing SWNT bundles using in situ nanomanipulation techniques inside a high-resolution scanning electron microscope. The in situ measurements clearly reveal the process of delaminating one SWNT bundle from its originally bound SWNT bundle in a controlled-displacement manner and capture the deformation curvature of the delaminated SWNT bundle during the peeling process. A theoretical model based on nonlinear elastica theory is employed to interpret the measured deformation curvatures of the SWNTs and to quantitatively evaluate the peeling force and the adhesion strength between bundled SWNTs. The estimated adhesion energy per unit length for each pair of neighboring tubes in the peeling interface based on our peeling experiments agrees reasonably well with the theoretical value. This in situ peeling technique provides a potential new method for separating bundled SWNTs without compromising their material properties. The combined peeling experiments and modeling presented in this paper will be very useful to the study of the adhesion interactions between SWNTs and their nonlinear mechanical behaviors in the large-displacement regime.

[Analysis of anti-microbial resistance of Escherichia coli that caused infection in urogenital system].

OBJECTIVE: To study the anti-microbial resistance of Escherichia coli (E.coli) that caused infection in urogenital system. METHOD: Anti-microbial susceptibility tests for 148 strains of E.coli were conducted by disc diffusion technique. RESULTS: In 28 commonly used antibiotics, the resistance rates of E. coli to beta-lactam and quinolones were high (73.6%-86.4%). High resistance rates to the first- and the second-generation cephalosporin (cefradime, cephazolin and cefaclor) were also observed (44%). Resistance rate to ceftazidime is the lowest (10.1%) in the third-generation cephalosporin. The resistance rates of E. coli to piperacillin, pefoperazone and ampicillin were 84.5%, 44.6% and 83.0% respectively. Combined antibiotic and beta-lactam inhibitor gave lower resistance rates than antibiotic alone (piperacillin/tazobactam, cefoporazone/sulbactam and ampicillin/sulbactam were 4.1%, 10.8% and 52.0% respectively, P<0.01). Of 148 E. coli isolates, 38 strains were capable of yielding extended-spectrum beta-lactamases (ESBLs) (25.7%), 110 strains were not able to produce ESBLs (74.3%) and the resistance rates of isolates with ESBLs to 28 antibiotics were significantly lower than those of isolates without ESBLs. CONCLUSION: Antibiotic/beta-lactam inhibitor and nitrofurantoin are effective for urogenital infections caused by E. coli.