Research progress on the application of cell-free synthesis systems for enzymatic processes.

Cell-free synthesis systems can complete the transcription and translation process to produce complex proteins that are difficult to be expressed in traditional cell-based systems. Such systems also can be used for the assembly of efficient localized multienzyme cascades to synthesize products that are toxic to cells. Cell-free synthesis systems provide a simpler and faster engineering solution than living cells, allowing unprecedented design freedom.

Study of the properties of carotenoids and key carotenoid biosynthesis genes from Deinococcus xibeiensis R13.

To investigate the properties of carotenoids from the extremophile Deinococcus xibeiensis R13, the factors affecting the stability of carotenoids extracted from D. xibeiensis R13, including temperature, illumination, pH, redox chemicals, metal ions, and food additives, were investigated. The results showed that low temperature, neutral pH, reducing agents, Mn , and food additives (xylose and glucose) can effectively improve the stability of Deinococcus carotenoids.

CEP55 Positively Affects Tumorigenesis of Esophageal Squamous Cell Carcinoma and Is Correlated with Poor Prognosis.

Centrosomal protein 55 (CEP55) is a centrosome- and midbody-associated protein that is overexpressed in several cancers. However, the underlying molecular mechanism of CEP55-mediated progression and metastasis of esophageal squamous cell carcinoma (ESCC) is not clear. In the current study, we detected CEP55 mRNA by qRT-PCR while protein expression was detected by western blot analysis and immunohistochemistry (IHC).

Stand out from matrix: Ultra-sensitive LC-MS/MS method for determination of histamine in complex biological samples using derivatization and solid phase extraction.

The determination of low abundant endogenous components is a challenge for the clinical samples. Histamine, a crucial endogenous component, fulfils various regulatory and mediatory functions in human, and the change of content is a critical index for the diagnosis of some diseases, especially allergy, asthma, and anaphylactic shock. However, it is challenging to detect histamine because of the low stability and concentration in complex biological samples.

Profiling of polyunsaturated fatty acids in human serum using off-line and on-line solid phase extraction-nano-liquid chromatography-quadrupole-time-of-flight mass spectrometry.

Polyunsaturated fatty acids (PUFAs) play a pivotal role in the biological effects, and are the potential biomarkers for some diseases. However, the structural diversity and similarity, the low concentration, and the interference of high abundant endogenous components challenge the PUFAs profiling. Herein, a novel analytical approach, off-line and on-line solid phase extraction-nano-liquid chromatography-quadrupole-time-of-flight mass spectrometry (off-line and on-line SPE-nano-LC-Q-TOF-MS), was established to monitor the PUFAs.

Microwave photonic phase-tunable mixer.

Traditional microwave photonic systems cannot implement frequency up-conversion with phase tunable capability, which plays an important role for phase array beamforming. Here, a method that can implement both upconversion and downconversion with a broadband full-degree phase-shift capability by constructing an optical path with a Hilbert transform function is presented. Owing to the Hilbert transform path, the dual-drive Mach-Zehnder modulator (DMZM) bias information, which initially influences the amplitudes of the output signals, are transferred to their phases.

GVD-insensitive stable radio frequency phase dissemination for arbitrary-access loop link.

We propose and experimentally demonstrate a stable radio frequency (RF) phase dissemination scheme for a long-haul optical fiber loop link based on frequency mixing. Using a single optical source in both directions of the loop link, additional timing jitter caused by group velocity dispersion (GVD) can be eliminated. Impressive scalability provided by the optical link ensures that arbitrary-access node can obtain an RF signal with a stabilized phase to meet the requirements of multiple users.

Photonic downconversion with tunable wideband phase shift.

A microwave photonic frequency downconversion system with wideband and continuous phase-shift function is proposed and experimentally demonstrated. In the proposed system, a radio frequency (RF) and a local oscillator (LO) signal drive two arms of a dual-drive Mach-Zehnder modulator (DMZM). A fiber Bragg grating (FBG) is used for reflecting the first-order sidebands of both RF and LO signals.

Measurement of the rotational Doppler frequency shift of a spinning object using a radio frequency orbital angular momentum beam.

An indirect approach based on phase measurement is proposed to measure the rotational Doppler frequency shift, which takes full advantage of the phase structure of orbital angular momentum (OAM) beams in radio domain, using a vector network analyzer (VNA) as a phase discriminator. A proof-of-concept experiment is established by an optical-controlled system with the OAM state of 1. By analyzing the experiment's results, the rotational Doppler frequency shift is measured as 24.

Shared end-to-content backup path protection in k-node (edge) content connected elastic optical datacenter networks.

To quantitatively measure content connectivity and provide protection for different kinds of content, the concept of k-node (edge) content connectivity is proposed recently. Based on k-node (edge) content connectivity, k-node (edge) content connected elastic optical datacenter network (KC-EODN) is proposed to design disaster-resilient and spectrum-efficient optical datacenter networks. In KC-EODN, k independent end-to-content paths are established for each request.

Rapid identification of new minor chemical constituents from Smilacis Glabrae Rhizoma by combined use of UHPLC-Q-TOF-MS, preparative HPLC and UHPLC-SPE-NMR-MS techniques.

Introduction: Herbs are an important resource for new drug development. However, the conventional approach for the discovery of new compounds from herbs was time-consuming, tedious, and inefficient.

Objectives: Establish a quick approach to identify new minor constituents in herbs.

Decreased Expression of FADS1 Predicts a Poor Prognosis in Patients with Esophageal Squamous Cell Carcinoma.

FADS1 (fatty acid desaturase 1) plays a crucial role in fatty acid metabolism, and it was recently reported to be involved in tumorigenesis. However, the role of FADS1 expression in esophageal squamous cell carcinoma (ESCC) remains unknown. In the current study, we investigated the expression and clinical pathologic and prognostic significance of FADS1 in ESCC.

Metabolites software-assisted flavonoid hunting in plants using ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry.

Plant secondary metabolism drives the generation of metabolites used for host plant resistance, as biopesticides and botanicals, even for the discovery of new therapeutics for human diseases. Flavonoids are one of the largest and most studied classes of specialized plant metabolites. To quickly identify the potential bioactive flavonoids in herbs, a metabolites software-assisted flavonoid hunting approach was developed, which mainly included three steps: firstly, utilizing commercial metabolite software, a flavonoids database was established based on the biosynthetic pathways; secondly, mass spectral data of components in herbs were acquired by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UHPLC-Q-TOF-MS); and finally, the acquired LC-MS data were imported into the database and the compounds in the herbs were automatically identified by comparison of their mass spectra with the theoretical values.

Photonic downconversion based on optical carrier bidirectional reusing in a phase modulator.

We propose a novel photonic downconversion method based on optical carrier reusing. In the proposed system, the phase modulator (PM) is placed between two narrowband fiber Bragg gratings (FBGs), which are designed to reflect the optical carrier and transmit the optical sidebands. The optical carrier is modulated in the PM in two directions and is not injected into the photodetector (PD).

Generating the orbital angular momentum of radio frequency signals using optical-true-time-delay unit based on optical spectrum processor.

A system for generating radio frequency signals with orbital angular momentum (OAM) is proposed and certificated for the first time, which employs an array of multiple optical-true-time-delay elements and circular antennas array (CAAs). A constructive Fourier series theory about CAAs collectively forming an OAM radio beam is demonstrated. An optical spectrum processor offers the four lines high-resolution time delay by adding a series of linear optical phase shifts.

Pre-configured polyhedron based protection against multi-link failures in optical mesh networks.

This paper focuses on random multi-link failures protection in optical mesh networks, instead of single, the dual or sequential failures of previous studies. Spare resource efficiency and failure robustness are major concerns in link protection strategy designing and a k-regular and k-edge connected structure is proved to be one of the optimal solutions for link protection network. Based on this, a novel pre-configured polyhedron based protection structure is proposed, and it could provide protection for both simultaneous and sequential random link failures with improved spare resource efficiency.

Third-order intermodulation distortion elimination of microwave photonics link based on integrated dual-drive dual-parallel Mach-Zehnder modulator.

A method to realize a highly linear microwave photonics link is proposed based on the dual-drive dual-parallel Mach-Zehnder modulator (MZM). The scheme theoretically eliminates third-order intermodulation distortion (IMD3) completely by taking all the sidebands in the optical spectrum that cause IMD3 into consideration. Without digital linearization and other optical processors, the method utilizes simple electrical signal phase control.

Path connectivity based spectral defragmentation in flexible bandwidth networks.

Optical networks with flexible bandwidth provisioning have become a very promising networking architecture. It enables efficient resource utilization and supports heterogeneous bandwidth demands. In this paper, two novel spectrum defragmentation approaches, i.

Beam wander of electromagnetic Gaussian-Schell model beams propagating in atmospheric turbulence.

The general model of beam wander for a coherent Gaussian beam propagating through atmospheric turbulence is extended to the case of a partially polarized electromagnetic Gaussian-Schell model (EGSM) beam. The expression of the beam wander is obtained by characterizing the EGSM beam with the effective beam parameters. The effects of initial spatially coherent lengths, degree of polarization, and phase curvature are examined in detail.

Analytical investigation of modulation instability in a fiber Bragg grating.

Modulation instability (MI) in a fiber Bragg grating (FBG) is investigated and reviewed analytically. The dispersion relation equation of MI obtained from the coupled-mode equation is solved exactly. The closed-form expressions of the gain of MI and the threshold condition in the normal dispersion regime are derived.

Effect of frequency chirp on supercontinuum generation in photonic crystal fibers with two zero-dispersion wavelengths.

The effect of initial frequency chirp is investigated numerically to obtain efficient supercontinuum radiation in photonic crystal fibers (PCFs) with two closely spaced zero-dispersion wavelengths. The positive chirps, instead of zero or negative chirps, are recommended because self phase modulation and four-wave mixing can be facilitated by employing positive chirps. In contrast with the complicated and irregular spectrum generated by negative-chirped pulse, the spectrums generated by positive-chirped pulses are wider and much more regular.