Covalent post-synthetic modification of MOFs as a fluorescent sensor for the efficient detection of the biomarker of cystinuria.

Cystinuria is a genetic disorder, and in severe cases, it might lead to kidney failure. As an important biomarker for cystinuria, the level of arginine (Arg) in urine is a vital indicator for cystinuria screening. Therefore, it is urgently needed to detect Arg with high selectivity and sensitivity. In this work, a boric acid functionalized Zr-based metal-organic framework UiO-PhbA is prepared by grafting phenylboronic acid on UiO-66-NH2 through a Schiff base reaction using a covalent post-synthesis modification (CPSM) strategy. The prepared UiO-PhbA exhibits a sensitive and specific fluorescence "turn-on" response to Arg and can be exploited to detect Arg in human serum and urine samples with a broad linear range of 0.6-350 µM and low limit of detection (LOD) of 18.45 nM. This study provides a new and reliable rapid screening protocol for sulfite oxidase deficiency-related diseases.

A Phytotoxin with Selective Herbicidal Activity and Related Metabolites from the Phytopathogenic Fungus Bipolaris cookei SYBL03.

Weeds are a serious threat to crop production, and the utilization of secondary metabolites of phytopathogenic fungi is considered to be an effective method of weed control. In this study, eight compounds were isolated and purified from the mycelium and fermentation broth extracts of Bipolaris cookei SYBL03. The compounds (1-8), except 2 and 6, are reported for the first time from this genus. The herbicidal activities of compounds 1-8 were studied by evaluating their effects on the seed germination and seedling growth of monocotyledonous and dicotyledonous weeds. The results indicated that compound 7 (Cyclo-N-methylphenylalanyltryptophenyl, cNMPT) exhibited a concentration-dependent dual effect on the growth of weed seedlings and selective herbicidal activity against dicotyledonous weeds. We further investigated the morphological and physiological responses of roots of Amaranthus retroflexus, a dicotyledonous weed, to compound 7. Some changes were found in seedlings grown in 400 µg/mL compound 7 solution for 96 h, such as shortening and swelling of elongation zone cells, reduced number and length of root hairs, damage and wrinkling of the root surface, occurrence of electrolyte leakage, and an increase in ethylene content. These results suggest that compound 7 may exert herbicidal activity by causing stress to weed seedlings. Increased ethylene production could be involved in the response of plants to compound 7.

Monolithically integrated 128-channel hybrid mode/polarization/wavelength (de)multiplexer on silicon-on-insulator.

In this paper, we proposed a 128-channel hybrid mode/polarization/wavelength (de)multiplexer by monolithically integrating four 16-wavelength-channel (de)multiplexers based on bi-directional MRRs arrays and an 8-channel hybrid mode/polarization (de)multiplexer. The hybrid mode/polarization (de)multiplexer consists of a polarization beam splitter (PBS) and cascaded six asymmetric directional couplers (ADCs). The present 128-channel hybrid (de)multiplexer utilizes four modes, dual polarizations, and sixteen wavelengths to improve the data transmission capacity of optical communication systems. For the fabricated hybrid (de)multiplexer, the channel spacing is 1.4 nm, and we used thermal tuning electrodes with a tuning efficiency of 0.45 nm/mW to calibrate resonance wavelengths. The measurement results show the insertion loss is 3∼8.5 dB, the inter-mode crosstalk is -7∼-23 dB, and the inter-wavelength crosstalk is-8∼-20 dB. The proposed (de)multiplexer is a promising approach to enhance the transmission capacity and has great potential in high-speed data transmission.

Photonic sampled and quantized analog-to- digital converters on thin-film lithium niobate platform.

In this paper, an on-chip photonic sampled and quantized analog-to-digital converter (ADC) on thin-film lithium niobate platform is experimentally demonstrated. Using two phase modulators as a sampler and a 5×5 multimode interference (MMI) coupler as a quantizer, a 1 GHz sinusoidal analog input signal was successfully converted to a digitized output with a 20 GSample/s sampling rate. To evaluate the system performance, the quantization curves together with the transfer function of the ADC were measured. The experimental effective number of bits (ENOB) was 3.17. The demonstrated device is capable of operating at a high frequency over 67 GHz, making it a promising solution for on-chip ultra-high speed analog-to-digital conversion.

Role of microbial microbes in arsenic bioaccumulation and biotransformation in mice.

Although gut microbes can affect the accumulation and metabolism of arsenic (As), the microbes contributing to these processes remain largely unknown. Therefore, this study aimed to investigate the bioaccumulation and biotransformation of arsenate [As(V)] and arsenobetaine (AsB) in mice with a disordered gut microbiome. We used cefoperazone (Cef) to construct a mouse model of gut microbiome disruption along with 16S rRNA sequencing to elucidate the effect of gut microbiome destruction on the biotransformation and bioaccumulation of As(V) and AsB. This revealed the role of specific bacteria in As metabolism. Gut microbiome destruction increased the bioaccumulation of As(V) and AsB in various organs and reduced the excretion of As(V) and AsB in the feces. Further, gut microbiome destruction was found to be important for the biotransformation of As(V). Interference with Cef can significantly decrease Blautia and Lactobacillus while increasing Enterococcus, leading to increase As accumulation in mice and enhanced methylation. We also identified Lachnoclostridium, Erysipelatoclostridium, Blautia, Lactobacillus, and Enterococcus as biomarkers involved in As bioaccumulation and biotransformation. In conclusion, specific microbes can increase As accumulation in the host, exacerbating its potential health risks.

Silicon nitride assisted tri-layer edge coupler on lithium niobate-on-insulator platform.

Lithium niobate-on-insulator (LNOI) is a promising integration platform for various applications, such as optical communication, microwave photonics, and nonlinear optics. To make Lithium niobate (LN) photonic integrated circuits (PICs) more practical, low-loss fiber-chip coupling is essential. In this Letter, we propose and experimentally demonstrate a silicon nitride (SiN) assisted tri-layer edge coupler on LNOI platform. The edge coupler consists of a bilayer LN taper and an interlayer coupling structure composed of an 80 nm-thick SiN waveguide and an LN strip waveguide. The measured fiber-chip coupling loss for the TE mode is 0.75 dB/facet at 1550 nm. Transition loss between the SiN waveguide and LN strip waveguide is ∼0.15 dB. In addition, the fabrication tolerance of the SiN waveguide in the tri-layer edge coupler is high.

Direct growth of graphene on hyper-doped silicon to enhance carrier transport for infrared photodetection.

The importance of infrared photodetectors cannot be overstated, especially in fields such as security, communication, and military. While silicon-based infrared photodetectors are widely used due to the maturity of the semiconductor industry, their band gap of 1.12 eV limits their infrared light absorption above 1100 nm, making them less effective. To overcome this limitation, we report a novel infrared photodetector prepared by growing graphene on the surface of zinc hyper-doped silicon. This technique utilizes hyper-doping to introduce deep level assisted infrared light absorption benefit from the enhanced carrier collection capacity of graphene. Without introducing new energy consumption, the hyper-doped substrate annealing treatment is completed during the growth of graphene. By the improvement of transport and collection of charge carriers, the graphene growth adjusts the band structure to upgrade electrode contact, resulting in a response of 1.6 mA W-1under laser irradiation with a wavelength of 1550 nm and a power of 2 mW. In comparison, the response of the photodetector without graphene was only 0.51 mA W-1, indicating a three-fold performance improvement. Additionally, the device has lower dark current and lower noise current, resulting in a noise equivalent power of 7.6 × 10-8W Hz-0.5. Thus, the combination of transition metal hyper-doping and graphene growth technology has enormous potential for developing the next generation of infrared photodetectors.

A novel electrochemical sensing platform based on double-active-center polyimide covalent organic frameworks for sensitive analysis of levofloxacin.

The development of a simple and sensitive electrochemical sensing platform for levofloxacin (LVF) analysis is of great significance to human health. In this work, a covalent organic framework (TP-COF) was in situ grown on the surface of Sn-MoC nanospheres with nanoflower-like morphology through a one-pot method to obtain the TP-COF@Sn-MoC composite. The prepared composite was used to modify a glassy carbon electrode (GCE) to realize the sensitive detection of levofloxacin. TP-COF was formed by polycondensation of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) and pyromellitic dianhydride (PMDA), in which C = O and C = N groups served as double active centers for the recognition and electrocatalytic oxidation of the target molecule. Meanwhile, the introduction of Sn-MoC improved the conductivity of the electrode. The TP-COF@Sn-MoC composite produced a strong synergistic effect and showed a high electrocatalytic ability toward levofloxacin oxidation. The linear range of LVF was 0.6-1000 µM and the limit of detection (LOD) was 0.029 µM (S/N = 3). In addition, the sensor has been successfully applied for the analysis of LVF in human urine and blood serum samples with acceptable recovery rates, demonstrating that the sensor was promising in practical applications.

Anti-Aphid Polyketides from Streptomyces sp. SA61.

Myzus persicae (Sulzer) is a crop pest causing serious economic losses around the world. For many decades, the management of M. persicae has relied heavily on chemical pesticides, resulting in the development of resistance, and new compounds with activity against M. persicae are needed. Five novel polyketides, strekingmycins A-E (1-5), were isolated from Streptomyces sp. SA61. Their structures were determined based on MS, NMR, and X-ray diffraction data. Strekingmycins were active against M. persicae between 4.4 and 9.4 µg/mL.

Temperature and organic carbon quality control the anaerobic carbon mineralization in peat profiles via modulating microbes: A case study of Changbai Mountain.

Peatlands account for a significant fraction of the global carbon stock. However, the complex interplay of abiotic and biotic factors governing anaerobic carbon mineralization in response to warming remains unclear. In this study, peat sediments were collected from a typical northern peatland-Changbai Mountain to investigate the behavior and mechanism of anaerobic carbon mineralization in response to depth (0-200 cm) and temperature (5 °C, 15 °C and 20 °C), by integrating geochemical and microbial analysis. Several indices including humification indexes (HI), aromaticity, and water extractable organic carbon (WEOC) components were applied to evaluate carbon quality, while 16S rRNA sequencing was used to measure microbial composition. Regardless of temperature, degradations of carbon quality and associated reduction in microbial abundance as well as diversity resulted in a decrease in anaerobic carbon mineralization (both CO2 and CH4) towards greater depth. Warming either from 5 °C to 15 °C or 20 °C significantly increased anaerobic carbon mineralization in all depth profiles by improving carbon availability. Enhanced carbon availabilities were mediated by the change in microbial composition (p < 0.01) and an increase in metabolic activities, which was particularly evident in the enhanced ß-glucosidase activity and microbial collaborations. A remarkable increase of over 10-fold in the relative abundance of the Geothrix genus was observed under warming. Overall, warming resulted in an enhanced contribution of CH4 emission and a higher ratio of hydrogenotrophic methanogenesis, as evidenced by carbon isotope fractionation factors. In addition, deep peat soils (>100 cm) with recalcitrant carbon demonstrated greater temperature sensitivity (Q10: ∼2.0) than shallow peat soils (Q10:∼1.2) when temperature increased from 15 °C to 20 °C. The findings of this study have significantly deepened our understanding for mechanisms of carbon quality and microbe-driven anaerobic carbon mineralization in peatlands under global warming.

Norsesquiterpenes from the Latex of Euphorbia dentata and Their Chemical Defense Mechanisms against Helicoverpa armigera.

Euphorbia dentata (Euphorbiaceae), an invasive weed, is rarely eaten by herbivorous insects and could secrete a large amount of white latex, causing a serious threat to local natural vegetation, agricultural production and human health. In order to prevent this plant from causing more negative effects on humans, it is necessary to understand and utilize the chemical relationships between the latex of E. dentata and herbivorous insects. In this study, three new norsesquiterpenes (1-3), together with seven known analogues (4-10), were isolated and identified from the latex of E. dentata. All norsesquiterpenes (1-10) showed antifeedant and growth-inhibitory effects on H. armigera with varying levels, especially compounds 1 and 2. In addition, the action mechanisms of active compounds (1-3) were revealed by detoxifying enzyme (AchE, CarE, GST and MFO) activities and corresponding molecular docking analyses. Our findings provide a new idea for the development and utilization of the latex of E. dentata, as well as a potential application of norsesquiterpenes in botanical insecticides.

Characterization of chemical constituents in Shuanghuanglian oral dosage forms by ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry.

Shuanghuanglian is a common traditional Chinese medicine prescription. It is an herbal formula composed of Lonicerae Japonicae Flos, Scutellariae Radix, and Forsythiae Fructus. A comprehensive understanding of Shuanghuanglian oral dosage forms components was obtained using a method based on ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry for the separation and characterization of Shuanghuanglian oral liquids, granules, soft capsules, and effervescent tablets. A total of 358 components were chemically defined or tentatively identified, including flavonoids, caffeic acid derivatives, lignans, coumarins, iridoids, triterpenes, and anthraquinones. The results will provide a basis for the general study of Shuanghuanglian and be meaningful for the composition identification of traditional Chinese medicine prescriptions.

Proteomic Analysis of Exudates from Chronic Ulcer of Diabetic Foot Treated with Scorpion Antimicrobial Peptide.

Scorpion peptides have good therapeutic effect on chronic ulcer of diabetic foot, but the related pharmacological mechanism has remained unclear. The different proteins and bacteria present in ulcer exudates from chronic diabetic foot patients, treated with scorpion antimicrobial peptide at different stages, were analyzed using isobaric tags for quantification-labeled proteomics and bacteriological methods. According to the mass spectrometry data, a total of 1865 proteins were identified qualitatively, and the number of the different proteins was 130 (mid/early), 401 (late/early), and 310 (mid, late/early). In addition, functional annotation, cluster analysis of effects and the analysis of signal pathway, transcription regulation, and protein-protein interaction network were carried out. The results showed that the biochemical changes of wound microenvironment during the treatment involved activated biological functions such as protein synthesis, cell proliferation, differentiation, migration, movement, and survival. Inhibited biological functions such as cell death, inflammatory response, immune diseases, and bacterial growth were also involved. Bacteriological analysis showed that Burkholderia cepacia was the main bacteria in the early and middle stage of ulcer exudate and Staphylococcus epidermidis in the late stage. This study provides basic data for further elucidation of the molecular mechanism of diabetic foot.

The effect of compatibility of Aconiti Radix and honey on the pharmacokinetics of five Aconitum alkaloids in rat plasma.

Aconiti Radix [Chuanwu (CW)] is widely used to treat chronic and intractable diseases due to its remarkable curative effect. CW has been combined with honey for thousands of years to reduce toxicity and enhance efficacy. This study first determined the compatibility mechanism of CW with honey using a comparative pharmacokinetic concept. We developed and validated a simple, sensitive, specific, and accurate UHPLC-MS/MS method to simultaneously determine five Aconitum alkaloids in rat plasma after the oral administration of CW decoction and CW-honey concentrated solution. Pharmacokinetic parameters were significantly different between the two groups (P < 0.01 and P < 0.05). Compared with the CW group, Cmax and AUC0 → t decreased in the CW-honey group for three diester-diterpenoid alkaloids (hypaconitine, mesaconitine, and aconitine); Tmax and T1/2 were prolonged. However, Cmax and AUC0 → t increased in the CW-honey group for two monoester-diterpenoid alkaloids (benzoylaconine and benzoylmesaconine); Tmax was shortened, and T1/2 was prolonged. These findings suggest that honey affected the pharmacokinetic behaviors of five Aconitum alkaloids. We speculate that the detoxification and synergism of honey might result from reducing the toxicity of diester-diterpenoid alkaloids and promoting the biological activity of monoester-diterpenoid alkaloids in vivo. This study provides a theoretical basis for the clinical use of CW combined with honey.

Application of Metabonomics in Substance Abuse Toxicology Research.

Abstrct: Metabonomics is a relative discipline that develops after genomics and proteomics, and it is an important component of systems biology. It uses high-throughput and high-sensitivity instruments to perform qualitative and quantitative analysis of all metabolic components in specific biological samples under limited conditions and combines with multivariate statistics to analyze and process the data to obtain information about physiological, pathological or toxicological changes in organisms. In recent years, because of the complicated mechanism of substance abuse and the continuous emergence of new psychoactive substances, metabonomics is increasingly used in substance abuse research. Therefore, this article reviews the application of metabonomics of substance abuse in the toxic mechanism, the mechanism of addiction and the discovery of biomarkers.

C-band four-channel CWDM (de-)multiplexers on a thin film lithium niobate-silicon rich nitride hybrid platform.

A four-channel coarse wavelength division multiplexing (CWDM) (de)multiplexer on a thin film lithium niobate-silicon rich nitride hybrid platform has been designed, fabricated, and experimentally measured. Enabled by cascaded multimode waveguide Bragg gratings, the (de)multiplexer has a box-like spectral response, wide 1-dB bandwidth (10 nm), low excess loss (<1.08dB), and low channel cross talk (<-18dB). The central wavelengths of the (de-)multiplexer are 1531/1551/1571/1591 nm, which align to the wavelength grids stipulated by the standard ITU-T G.694.2.

On-chip four-mode (de-)multiplexer on thin film lithium niobate-silicon rich nitride hybrid platform.

A four-mode (de-)multiplexer with transverse electric field light (TE0-TE3) is experimentally demonstrated on a thin film lithium niobate-silicon rich nitride hybrid platform. Enabled by cascaded asymmetrical directional couplers, a (de-)multiplexer with low insertion loss (0.38 dB to 1.6 dB) and low cross talk (-18.46dB to -20.43dB) is obtained at 1550 nm. All channels have cross talk <-16dB from 1480 nm to 1580 nm. The transmission of 4×50 Gbps on-off keying signals is experimentally achieved on the proposed (de-)multiplexer. Experimental results show that the proposed (de-)multiplexer is a promising approach to enhance the transmission capacity in thin film lithium niobate based photonics integrated circuits.

Screening of differential components of Gegenqinlian decoction and their comparative pharmacokinetics in normal and pyrexia rats using UHPLC-FT-ICR-MS and UHPLC-MS/MS.

UHPLC combined with Fourier-transform ion cyclotron resonance MS metabonomic approach was employed to screen the differential components between normal rats and yeast-induced pyrexia rats after an oral administration of Gegenqinlian decoction (GQLD). Nine compounds, namely puerarin, daidzein, baicalin, wogonoside, wogonin, berberine, palmatine, jateorhizine, and coptisine, were identified as differential components in the plasma. A rapid, sensitive, selective, and accurate UHPLC-MS method was developed and fully validated for the simultaneous determination of the screened components in rat plasma after an oral administration of GQLD. The values for the limit of quantification ranged from 0.025 to 5.0 ng/mL. The inter- and intra-day precision of all analytes was ≤10.7%, with an accuracy of ≤10.5%. Good extraction recovery and matrix effects were also obtained. The method was successfully applied to a comparative pharmacokinetic study of GQLD in normal and pyrexia rats. The results showed that the pharmacokinetic behavior of the analytes was changed in pyrexia rats compared to normal rats. These results could provide beneficial guidance for clinical applications of GQLD.

High-Throughput Identification of Organic Compounds from Polygoni Multiflori Radix Praeparata (Zhiheshouwu) by UHPLC-Q-Exactive Orbitrap-MS.

Polygoni Multiflori Radix Praeparata (PMRP), as the processed product of tuberous roots of Polygonum multiflorum Thunb., is one of the most famous traditional Chinese medicines, with a long history. However, in recent years, liver adverse reactions linked to PMRP have been frequently reported. Our work attempted to investigate the chemical constituents of PMRP for clinical research and safe medication. In this study, an effective and rapid method was established to separate and characterize the constituents in PMRP by combining ultra-high performance liquid chromatography with hybrid quadrupole-orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS). Based on the accurate mass measurements for molecular and characteristic fragment ions, a total of 103 compounds, including 24 anthraquinones, 21 stilbenes, 15 phenolic acids, 14 flavones, and 29 other compounds were identified or tentatively characterized. Forty-eight compounds were tentatively characterized from PMRP for the first time, and their fragmentation behaviors were summarized. There were 101 components in PMRP ethanol extract (PMRPE) and 91 components in PMRP water extract (PMRPW). Simultaneously, the peak areas of several potential xenobiotic components were compared in the detection, which showed that PMRPE has a higher content of anthraquinones and stilbenes. The obtained results can be used in pharmacological and toxicological research and provided useful information for further in vitro and in vivo studies.

Efficient Gene Therapy of Pancreatic Cancer via a Peptide Nucleic Acid (PNA)-Loaded Layered Double Hydroxides (LDH) Nanoplatform.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest malignant tumors with extremely poor prognosis due to the later stage diagnosis when surgical resection is no longer applicable. Alternatively, the traditional gene therapy which drives pancreatic cancer cells into an inactive state and inhibiting the proliferation and metastasis, presents potentials to safely inhibit pancreatic cancer progression, but unfortunately has received limited success to date. Here, an efficient gene therapy of pancreatic cancer is shown via a peptide nucleic acid (PNA)-loaded layered double hydroxides (LDHs) nanoplatform. Compared with the traditional DNA- or RNA-based gene therapies, the gene therapy using PNA features great advantages in recognizing and hybridizing with the target mutant sequences to form PNA-DNA hybrids with significantly enhanced stability due to the absence of electrostatic repulsion, and the constrained flexibility of the polyamide backbone. Moreover, ultrasmall LDHs are engineered to load PNA and the obtained PNA-loaded LDH platform (LDHs/PNA) is capable of efficiently and selectively targeting the intranuclear mutant sequences thanks to the proton sponge effect. Treatments with LDHs/PNA demonstrate markedly inhibited growth of pancreatic cancer xenografts via a cancer cell proliferation suppression mechanism. The results demonstrate the great potentials of LDHs/PNA as a highly promising gene therapy agent for PDAC.