Spectral recovery of broadband waveforms via cross-phase modulation based tunable Talbot amplifier.

Physical processes in the Fourier domain play a crucial role in various applications such as spectroscopy, quantum technology, ranging, radio-astronomy, and telecommunications. However, the presence of stochastic noise poses a significant challenge in the detection of broadband spectral waveforms, especially those with limited power. In this study, we propose and experimentally demonstrate a cross-phase modulation (XPM) based spectral Talbot amplifier to recover the broadband spectral waveforms in high fidelity. Through the combination of spectral phase filtering and XPM nonlinear effect in an all-fiber configuration, we demonstrate spectral purification of THz-bandwidth spectral waveforms submerged in strong noise. The proposed spectral Talbot amplifier provides tunable amplification factors from 3 to 10, achieved by flexible control on the temporal waveform of the pump and the net dispersion. We demonstrate up to 10-dB remarkable improvement on optical signal-to-noise ratio (OSNR) while preserving the spectral envelope. Furthermore, our system allows frequency-selective reconstruction of noisy input spectra, introducing a new level of flexibility for spectral recovery and information extraction. We also evaluate numerically the impact of pump intensity deviation on the reconstructed spectral waveforms. Our all-optical approach presents a powerful means for effective recovery of broadband spectral waveforms, enabling information extraction from a noise-buried background.

Capacity enhancement through entropy loading with probabilistically shaped signals in a frequency comb-based transmission system.

We demonstrate a multichannel entropy loading mechanism in an optical frequency comb-based coherent communication system. In high-capacity wavelength division multiplexing communications, the individual laser sources can be replaced by an optical frequency comb, thus reducing the complexity and energy consumption of the transmitter. However, the power variation among different comb lines will lead to performance discrepancies. Spectral flattening filters can be adopted to suppress the variation at the expense of an additional system loss. Alternatively, by applying probabilistic shaping, we have implemented multichannel entropy loading to facilitate a continuous adaptation of the source entropy. The data rate can be dynamically allocated according to the performance of each channel. Through the loading scheme, the non-uniform performances across the channels are effectively mitigated, achieving a capacity enhancement of 34.91 Gbit/s.

TaGSK3 regulates wheat development and stress adaptation through BR-dependent and BR-independent pathways.

The GSK3/SHAGGY-like kinase plays critical roles in plant development and response to stress, but its specific function remains largely unknown in wheat (Triticum aestivum L.). In this study, we investigated the function of TaGSK3, a GSK3/SHAGGY-like kinase, in wheat development and response to stress. Our findings demonstrated that TaGSK3 mutants had significant effects on wheat seedling development and brassinosteroid (BR) signalling. Quadruple and quintuple mutants showed amplified BR signalling, promoting seedling development, while a sextuple mutant displayed severe developmental defects but still responded to exogenous BR signals, indicating redundancy and non-BR-related functions of TaGSK3. A gain-of-function mutation in TaGSK3-3D disrupted BR signalling, resulting in compact and dwarf plant architecture. Notably, this mutation conferred significant drought and heat stress resistance of wheat, and enhanced heat tolerance independent of BR signalling, unlike knock-down mutants. Further research revealed that this mutation maintains a higher relative water content by regulating stomatal-mediated water loss and maintains a lower ROS level to reduces cell damage, enabling better growth under stress. Our study provides comprehensive insights into the role of TaGSK3 in wheat development, stress response, and BR signal transduction, offering potential for modifying TaGSK3 to improve agronomic traits and enhance stress resistance in wheat.

Carboxylic Acid-Enabled Vinylene Transfer Reaction by Co(III) Catalyst: Scope and Applications to the Five-Step Total Synthesis of Protoberberine Alkaloids Containing Free Hydroxyl Group without Protection.

A Co(III)-catalyzed vinylene transfer reaction enabled by carboxylic acid is presented. This redox-neutral transformation tolerates various functional groups, including free hydroxyl groups, and features practicality. Five-step routes based on the vinylene transfer reaction and Heck annulation have been devised to the total synthesis of 8-oxodehydrodiscretamine and 2-demethyl-oxypalmatine without the protection of the free hydroxyl functionality.

Enhancing Systemic Translocation of Insecticides via Nanoformulations Incorporating ß-Cyclodextrin Octadecarboxylate as a Carrier.

The conversion of contact-killing pesticides into systemic pesticides can significantly enhance the bioavailability of pesticides, thereby reducing pesticide usage and environmental harm. A series of ß-cyclodextrin fatty acid esters with varying branch chains were synthesized and employed as carriers in nanoformulation of insecticide. The investigation revealed that nanoformulations prepared using ß-cyclodextrin octadecarboxylate (ß-CDs) exhibited superior stability and remarkable systemic translocation within plants. Six contact-killing insecticide nanoformulations were developed utilizing ß-CDs as carriers, and tests indicated that ß-CDs significantly enhanced the systemic translocation of insecticides in plants compared to carrier-free nanoformulations. It was found that ß-CDs increased the level of systemic translocation of insecticides by 5-12 times. Additionally, characterization results from λ-cyhalothrin-ß-CDs nanoformulation demonstrated their superior ability to improve photolysis resistance, prolong release time, and extend insecticidal duration. Consequently, ß-CDs can be utilized as a green additive in pesticide production to enhance the systemic translocation of pesticides in plants and increase their bioavailability.

Construction and management of smart campus: Anti-disturbance control of flexible manipulator based on PDE modeling.

With the rapid development of smart campus, this paper studies the attitude tracking control of flexible manipulator (FM) in colleges and universities under elastic vibration and external disturbances. First, different from the traditional modeling based on ordinary differential equations (ODEs), the partial differential equations (PDEs) dynamic model of a manipulator system is established based on the Hamilton principle (HP). Second, the boundary control condition of the end system of the manipulator is introduced to adjust the vibration of the manipulator. Furthermore, a Proportional-Derivative (PD) boundary control (PDBC) strategy is proposed by the Lyapunov function to suppress the vibration of the manipulator. Finally, a numerical comparison simulation based on MATLAB/SIMULINK further verifies the robustness and anti-disturbance performance of the control method proposed in this paper.

Selective Terminal Functionalization of Linear Alkanes.

A two-step sequential strategy involving a biocatalytic dehydrogenation/remote hydrofunctionalization, as a unified and versatile approach to selectively convert linear alkanes into a large array of valuable functionalized aliphatic derivatives is reported. The dehydrogenation is carried out by a mutant strain of a bacteria Rhodococcus and the produced alkenes are subsequently engaged in a remote functionalization through a metal-catalyzed hydrometalation/migration sequence that subsequently react with a large variety of electrophiles. The judicious implementation of this combined biocatalytic and organometallic approach enabled us to develop a high-yielding protocol to site-selectively functionalize unreactive primary C-H bonds.

Synthesis, characterization and application of emamectin-alkaline lignin conjugate with photolysis resistance and systemic translocation.

Controlled release formulations (CRFs) are a key technical approach for the sustainable development of pesticides. In this study, a CRF conjugate (emamectin-alkaline lignin, EB-AL) was successfully prepared using alkaline lignin as the substrate, with amide bond connecting emamectin and alkaline lignin. The structure and morphology of the conjugate were characterized using IR, 1HNMR, elemental analysis, SEM and TG. The release of EB-AL showed that the conjugate maintained its original structure when released in 50 % methanol-water and soil column, and the amide bond remained intact. The anti-photolysis test revealed that EB-AL had a 3.5 times higher photolysis half-life T0.5 than the general emamectin suspension concentrate (EB-SC). Bioactivity tests in the greenhouse demonstrated that EB-AL possessed a longer insecticidal duration and good biosafety. Ostrinia nubilalis lethality rate remained above 70 % for 19 days, while EB-EC, the control, had a rate of <50 % after 11 days of application. Additionally, EB-AL conjugate demonstrated excellent systemic translocation in plants, likely due to its ability to mediate alkaline lignin.

Synthesis and antitumor activity of some cholesterol-based selenocyanate compounds.

The introduction of selenium-containing functional groups into steroids to study the biological activities of related derivatives is rarely reported in the literature. In the present study, using cholesterol as raw material, four cholesterol-3-selenocyanoates and eight B-norcholesterol selenocyanate derivatives were synthesized, respectively. The structures of the compounds were characterized by NMR and MS. The results of the in vitro antiproliferative activity test showed that the cholesterol-3-selenocyanoate derivatives did not exhibit obvious inhibitory on the tested tumor cell lines. However, the B-norcholesterol selenocyanate derivatives obtained by structural modification of cholesterol showed good inhibitory activity against the proliferation of tumor cell. Among them, compounds 9b-c, 9f and 12 showed similar inhibitory activity against tested tumor cells as positive control 2-methoxyestradiol, and better than Abiraterone. At the same time, these B-norcholesterol selenocyanate derivatives displayed a strong selective inhibitory against Sk-Ov-3 cell line. Except for compound 9g, the IC50 value of all B-norcholesterol selenocyanate compounds against Sk-Ov-3 cells was less than 10 µM, and compound 9d was 3.4 µM. In addition, Annexin V-FITC/PI double staining was used to analyze the cell death mechanism. The results showed that compound 9c could induce Sk-Ov-3 cells to enter programmed apoptosis in a dose-dependent manner. Furthermore, the in vivo antitumor experiments of compound 9f against zebrafish xenograft tumor showed that 9f displayed obvious inhibitory effect on the growth of human cervical cancer (HeLa) xenograft tumor in zebrafish. Our results provide new thinking for the study of such compounds as new antitumor drugs.

Synthesis of estrone selenocyanate Compounds, anti-tumor activity evaluation and Structure-activity relationship analysis.

Introducing different functional groups into steroid can bring unexpected changes in biological activity of the steroid. Using estrone as a raw material, through the functional group conversion and modification of the 17-carbonyl, the structural fragments with selenocyano groups were instilled in the form of amide, ester, and oxime ester, respectively, and various 17-substituted estrone selenocyanate derivatives were synthesized. In addition, different 3-substituted estrone selenocyanate derivatives were synthesized by introducing different selenocyanoalkoxy fragments into the 3-position of estrone in the form of alkyl ether. Furthermore, the selenocyano-containing moieties were embedded into the 2-position of estrone by means of amide, affording diverse 2-selenocyanoamide-estrone derivatives. The antiproliferative activities of the target compounds were screened by selecting tumor cell lines related to the expression of human hormones. The results showed that the introduction of selenocyano group into estrone could endow estrone with significant biological activity of inhibiting the proliferation of tumor cells. Structure-activity relationship research showed that the cytotoxicity of 3-selenocyanoalkoxy-estrone was further increased with the extension of alkyl carbon-chain within 8 carbon chain lengths. In addition, the cytotoxicity of the products with selenocyano via the form of amide was stronger than that of ester or ether. Selenocyano moiety instilled at the 2-position of estrone in the form of amide was more cytotoxic than that of 17- or 3-position. Among them, compound 21a has better inhibitory activity on tested tumor cells than positive controls Abiraterone and 2-methoxyestradiol. Research showed that the compound 21c induced programmed apoptosis in Sk-Ov-3 cancer cells, and compound 17d inhibited significantly the growth of human cervical cancer zebrafish xenografts in vivo, offering useful insights into the synthesis of steroid antitumor drugs.

Rh(III)-Catalyzed Synthesis of Amino-isocoumarins with N-Functionalized Cyclic Carbonates via C-H/O-H Annulation.

A practical method to access amino-isocoumarins catalyzed by a Rh(III) complex through redox-neutral C-H/O-H annulation has been disclosed. The use of N-functionalized cyclic carbonates is crucial to facilitate the catalytic turnover, and a broad spectrum of amino-isocoumarin derivatives were prepared with satisfactory yields. Amino-isocoumarin estrone conjugated with a selenocyano functionality was identified to be nearly four times as active as the marketed drug abiraterone against T47D cancer cells.

Preparation and Insecticidal Activity Evaluation of Emamectin-Lignin Sulfonic Acid Conjugate with Antiphotolysis Property.

Controlled release formulations (CRFs) are considered an effective way to solve the low bioavailability of traditional pesticides. However, CRFs prepared by coating or encapsulation has the disadvantage of explosive release of the ingredients. Sustained-release pesticides prepared by coupling with a carrier can overcome this shortcoming. In the present study, an emamectin-lignin sulfonic acid conjugate (EB-SL), in which emamectin was connected via sulfonamide bonds with lignin, was prepared using sodium lignosulfonate as the carrier. The structure of the conjugate was characterized by IR, 1HNMR, and elemental analysis. The sustained-release results showed that EB-SL maintained its original structure when released in pure water and soil columns, and the sulfamide bond did not break. The photolysis test displayed that the photolysis half-life T 0.5 of EB-SL was increased by 1.5 times compared with the emamectin suspending concentrate (EB-SC). Bioactivity tests in the greenhouse showed that EB-SL not only had similar insecticidal toxicity to emamectin emulsion concentrate (EB-EC) against Ostrinia nubilalis but also displayed a longer duration. The lethality of EB-SL on O. nubilalis was maintained at more than 70% across 19 days, whereas EB-EC as the control was less than 50% after 11 days of application.

Tunable optical frequency comb with hundred-GHz spacings generated on a silicon waveguide.

We demonstrate the generation of optical frequency combs with tunable spacing at the hundred-GHz range in the 1550-nm window. The widely spaced combs are realized through silicon-based cross-phase modulation. The optical pump is prepared by multiplication of a 10-GHz train of 1.7-ps pedestal-free pulses. Energy-efficient temporal Talbot processing is used to multiply the repetition rate by a factor of up to 20. In our approach, the multiplication factor can be flexibly controlled by tuning the temporal dispersion inside an optical processor. Optical frequency combs with spacings ranging from 140 to 200 GHz have been successfully generated with a maximum carrier-to-noise suppression ratio of ∼45 dB.

Study on the preparation of sustained-release thiamethoxam microspheres by blending microcrystalline wax with tapioca starch ester or dehydroabietic acid ester as the matrix.

The controlled release formulations (CRFs) are considered an effective way to solve damage to the environment caused by traditional pesticide formulations. To change the defects of traditional neonicotinoid formulations that dissolve quickly in soil, three types of thiamethoxam (TM) CRFs microspheres with content of 20% TM were prepared using microcrystalline wax (MK) as the matrix, laurate acid tapioca starch ester (MSK) and stearyl dehydroabietic acid ester (MDK) as the regulators of ingredient release. The release behavior of CRFs microspheres in water and soil showed that the microspheres had superior stability and different TM sustained-release periods, and TM release of the microspheres in soil was faster than that in water. The release rate is TM/MDK > TM/MSK > TM/MK. In water, the release of thiamethoxam technical was finished after 38 hours. However, for TM/MK, the release rate was 94% after 240 hours, and the release time was extended by 6 times. Meanwhile, TM/MDK has a particular pH-responsive release. Research shows that using microcrystalline wax as the matrix, by adding MSK or MDK to adjust the release of ingredients, pesticide CRFs microspheres with different release periods can be prepared to achieve the purpose of controlling the release of pesticides.

Synthesis and antiproliferative evaluation of some novel estradiol selenocyanates.

Selenocyano fragments with different structural characteristics have been successfully installed into the 3- and 17-position of estradiol through the etherification and esterification of its 3 or 17-hydroxyl group respectively. A total of 12 new estradiol selenocyanates were synthesized and their structures were characterized by NMR and HRMS. The tumor cell lines related to the expression of human hormones were selected as the screening objects, and the antiproliferative activity of the target compounds was further investigated. The results showed that the introduction of selenocyano group in estradiol could endue estradiol with the activity of inhibiting tumor cell proliferation, and 3-selenocyanoalkyl estradiol ethers had stronger cytotoxicity than their 17-selenocyanocarboxylates counterpart. Among them, IC50 value of compound 3e on HeLa cells was 5.69 µM. The information obtained from the studies may be useful for the design and development of novel chemotherapeutic drugs.

Fabrication and evaluation of slow-release lignin-based avermectin nano-delivery system with UV-shielding property.

Nanopesticide is one of the best pesticide formulation technologies to overcome the disadvantages of traditional pesticides, which has received great attention from the international community. Using high-speed emulsification and ultrasonic dispersion technology, an avermectin nano-delivery system (Av-NDs) with a particle size of 80-150 nm was prepared through embedding the pesticide molecule utilizing the cross-linking reaction between sodium lignosulfonate and p-phenylenediamine diazonium salt. The formulation and composition of Av-NDs were optimized, the morphology of Av-NDs was analyzed by scanning electron microscope, transmission electron microscope and dynamic light scattering, and the structure of Av-NDs was characterized by UV, IR and 1H NMR. Anti-photolysis and controlled-release tests show that the stability of Av-NDs is 3-4 times of the original avermectin (Av) and possesses the pH-responsive controlled release property. Furthermore, the insecticidal activity of Av-NDs is better than that of avermectin suspension concentrate (Av-SC). The Av-NDs with anti-photolysis and controlled-release characteristics is suitable for large-scale industrial production and is capable to be utilized as effective insecticide in the field.

Rinegan: A Scalable Image Processing Architecture for Large Scale Surveillance Applications.

Image processing is widely used in intelligent robots, significantly improving the surveillance capabilities of smart buildings, industrial parks, and border ports. However, relying on the camera installed in a single robot is not enough since it only provides a narrow field of view as well as limited processing performance. Specially, a target person such as the suspect may appear anywhere and tracking the suspect in such a large-scale scene requires cooperation between fixed cameras and patrol robots. This induces a significant surge in demand for data, computing resources, as well as networking infrastructures. In this work, we develop a scalable architecture to optimize image processing efficacy and response rate for visual ability. In this architecture, the lightweight pre-process and object detection functions are deployed on the gateway-side to minimize the bandwidth consumption. Cloud-side servers receive solely the recognized data rather than entire image or video streams to identify specific suspect. Then the cloud-side sends the information to the robot, and the robot completes the corresponding tracking task. All these functions are implemented and orchestrated based on micro-service architecture to improve the flexibility. We implement a prototype system, called Rinegan, and evaluate it in an in-lab testing environment. The result shows that Rinegan is able to improve the effectiveness and efficacy of image processing.

Co(III)-Catalyzed Annulative Vinylene Transfer via C-H Activation: Three-Step Total Synthesis of 8-Oxopseudopalmatine and Oxopalmatine.

The Co(III)-catalyzed redox-neutral annulation of benzamides and acrylamides with vinylene carbonate for the synthesis of isoquinolinones and pyridinones has been developed. This protocol employing inexpensive Co(III) as the catalyst tolerated diverse functional groups and substitution patterns, affording the target products with good to excellent yields. The synthetic utility of this transformation was demonstrated by a three-step synthesis of gusanlung D, 8-oxopseudopalmatine, and oxopalmatine.

Iodide-enhanced palladium catalysis via formation of iodide-bridged binuclear palladium complex.

The prevalence of metalloenzymes with multinuclear metal complexes in their active sites inspires chemists' interest in the development of multinuclear catalysts. Studies in this area commonly focus on binuclear catalysts containing either metal-metal bond or electronically discrete, conformationally advantageous metal centres connected by multidentate ligands, while in many multinuclear metalloenzymes the metal centres are bridged through µ2-ligands without a metal-metal bond. We report herein a µ2-iodide-bridged binuclear palladium catalyst which accelerates the C-H nitrosation/annulation reaction and significantly enhances its yield compared with palladium acetate catalyst. The superior activity of this binuclear palladium catalyst is attributed to the trans effect-relay through the iodide bridge from one palladium sphere to the other palladium sphere, which facilitates dissociation of the stable six-membered chelating ring in palladium intermediate and accelerates the catalytic cycle. Such a trans effect-relay represents a bimetallic cooperation mode and may open an avenue to design and develop multinuclear catalysts.

Rh(iii)-catalyzed spiroannulation of 3-arylquinoxalin-2(1H)-ones with alkynes: practical access to spiroquinoxalinones.

The Rh(iii)-catalyzed synthesis of spiroquinoxalinone derivatives from 3-arylquinoxalin-2(1H)-ones and alkynes via a C-H functionalization/[3 + 2] annulation sequence has been developed. This method, featuring low catalyst loading, was amenable to Gram scale synthesis and tolerated a variety of functional groups and substitution patterns on the aryl rings, providing the target products in good to excellent yields.