Hasil untuk "q-bio"

Mengyu Li, H. Luo, Zhen-Cong Huang et al.

Erdong Gao (EDG), consisting equally of roots of Asparagi Radix and Ophiopogonis Radix, is a well-known traditional Chinese formulation that has been used to treat cough and throat pain for centuries. However, the bioactive components in EDG remain to be elucidated. In this study, a rapid and effective method involving live cell bio-specific extraction and HPLC-Q-TOF-MS/MS was established to rapidly screen and identify the anti-inflammatory compounds of an EDG extract. One hundred and twenty-four components were identified in EDG extract using HPLC-Q-TOF-MS/MS analysis. After co-incubation with 16HBE, HPAEpiCs and HUVECs, which have been validated as the key target cells for pulmonary diseases, sixteen components were demonstrated to exhibit an affinity for binding to them. Furthermore, fifteen components were subsequently verified to exert anti-inflammatory effects on lipopolysaccharide (LPS)-induced 16HBE, HPAEpiCs and HUVECs via inhibiting the release of TNF-α and IL-6, indicating that nine steroidal saponins may possess potential for the treatment of lung-related diseases. Taken together, our study provides evidence that live cell biospecific extraction combined with the HPLC-Q-TOF-MS/MS technique was an efficient method for rapid screening potential bioactive components in traditional Chinese medicines and the structure activity relationship of steroidal saponins in EDG was summarized for the first time.

Juan Huang, Shuyi Huang, Jing Zhang et al.

2,3,5,4'-Tetrahydroxystilbene-2-O-β-d-glucoside (THSG), a polyphenol stilbene compound, is the main active constituent in Polygonum multiflorum. In this study, a comprehensive analytical strategy was developed for the characterization of THSG metabolites in vivo (rat plasma, bile, urine, heart, liver, spleen, lung, kidney, and stomach) utilizing ultrahigh performance liquid chromatography coupled with Q Exactive hybrid quadrupole-Orbitrap mass spectrometry (UHPLC-Q Exactive-Orbitrap MS) based on multiple data-processing techniques. As a result, a total of 75 metabolites were characterized in bio-samples, and calculated Clog P values were further employed to assign the chemical structures of some isomers. Glucoside hydrolysis, hydrogenation, hydroxylation, glucuronide conjugation, and sulfate conjugation would be the major metabolic pathways of THSG. It appeared that most metabolites would generally undergo phase I reactions followed by phase II reactions. These results provided valuable information for in-depth understanding of the safety and efficacy of THSG and showed a valuable methodology for metabolic characterization.

L. Ding, D. Eschimèse, T. Ang et al.

Label-free optical biosensors using nanophotonic concepts have made substantial progress in the last few years due to their ability to realize fast, compact and cost-effective chemical detection devices. Among those, high refractive index dielectric Mie nanoresonators hold promise for deep miniaturization of bio-sensing devices while keeping high sensitivity and low dissipative losses. In this work, we report a high sensitivity and small footprint refractive index sensor based on this concept. The device consists of a one-dimensional chain of coupled silicon nanoresonators supporting high quality factor collective Mie modes. The measurements with aqueous glycerol solutions show a high sensitivity range of 420 – 440 nm/RIU and a maximum figure of merit of 2700 RIU -1 . Being fully compatible with standard CMOS processes and having a small sensing area of only 0.5×18.2 µm 2 , we believe this design, once arranged in arrays functionalized for different analytes, could become an attractive solution to realize lab-on-a-chip sensor arrays for high-performance, label-free multiplexing in a cost-effective way.

Ji-Hoon Suh, Haidam Choi, Yoontae Jung et al.

Electrical impedance tomography (EIT) is widely used for functional imaging of the bio-impedance of body parts for various applications, such as lung ventilation monitoring [1]. It was recently shown that ‘fast neural EIT’ with far enhanced temporal resolution (frame rate) can provide the neural activity monitoring and functional localization of the active peripheral nerve at the same time [2]. In an EIT system, to reconstruct an impedance tomography image (Fig. 1(a)), an AC current is injected from a current generator $(\text{I}_{\text{CG}})$ into the target bio-impedance network $\text{Z}_{\text{BIO}}$ through an electrode pair (channel) in a rotational manner, while demodulating the voltages appeared at all the other channels. The I/Q demodulation is the most popular way to extract the resistance and reactance information of $\text{Z}_{\text{BIO}}$ [1]. For the neural EIT, however, this method cannot support a high enough frame rate, failing to acquire neural activities, mainly due to the down-conversion to DC and low-pass filtering. As shown in Fig. 1(a), many cycles of the AC input signal are needed for the I and Q outputs to be well settled to their final values. A higher excitation frequency $(\text{f}_{\text{CG}})$ can be used for faster settling in conventional applications, but in the neural EIT, $\text{f}_{\text{CG}}$ should be $\lt 20$ kHz for high SNR image acquisition [2]. Alternatively, peak detection can be used [3], but it needs a much faster sampling clock than $\text{f}_{\text{CG}}$, consuming a large dynamic power in all the demodulation channels.

Kullathida Thongbhubate, Kanako Irie, Yumi Sakai et al.

In the bio-based polymer industry, putrescine is in the spotlight for use as a material. We constructed strains of Escherichia coli to assess its putrescine production capabilities through the arginine decarboxylase pathway in batch fermentation. N -Acetylglutamate (ArgA) synthase is subjected to feedback inhibition by arginine. Therefore, the 19th amino acid residue, Tyr, of argA was substituted with Cys to desensitize the feedback inhibition of arginine, resulting in improved putrescine production. The inefficient initiation codon GTG of argA was substituted with the effective ATG codon, but its replacement did not affect putrescine production. The essential genes for the putrescine production pathway, speA and speB , were cloned into the same plasmid with argA ATG Y19C to form an operon. These genes were introduced under different promoters; lacI p, lacI q p, lacI q1 p, and T5p. Among these, the T5 promoter demonstrated the best putrescine production. In addition, disruption of the puuA gene encoding enzyme of the first step of putrescine degradation pathway increased the putrescine production. Of note, putrescine production was not affected by the disruption of patA, which encodes putrescine aminotransferase, the initial enzyme of another putrescine utilization pathway. We also report that the strain KT160, which has a genomic mutation of YifE Q100TAG , had the greatest putrescine production. At 48 h of batch fermentation, strain KT160 grown in terrific broth with 0.01 mM IPTG produced 19.8 mM of putrescine.

T. Pato, Marta Cristina O Souza, Diogo A. Mattos et al.

Yellow fever (YF) is a high-lethality viral disease, endemic in tropical regions of South America and Africa, with a population of over 900 million people under risk. A highly effective attenuated vaccine, produced in embryonated eggs, has been used for about 80 years. However, egg-based production limits manufacturing capacity, and vaccine shortage led to the emergency use of a fractional dose (1/5) by the WHO in an outbreak in Africa in 2016 and by Brazilian authorities during an outbreak in 2018. In addition, rare but fatal adverse events of this vaccine have been reported since 2001. These two aspects make clear the need for the development of a new vaccine. In an effort to develop an inactivated YF vaccine, Bio-Manguinhos/FIOCRUZ started developing a new vaccine based on the production of the attenuated 17DD virus in serum-free conditions in Vero cells propagated in bioreactors, followed by chromatography-based purification and β-propiolactone inactivation. Virus purification was studied in this work. Capture was performed using an anion-exchange membrane adsorber (Sartobind® Q), resulting in a virus recovery of 80.2 ± 4.8% and a residual DNA level of 1.3 ± 1.6 ng/dose, thus in accordance with the recommendations of the WHO (<10 ng/dose). However, the level of host cell proteins (HCP) was still high for a human vaccine, so a second chromatography step was developed based on a multimodal resin (Capto™ Core 700). This step resulted in a virus recovery of 65.7 ± 4.8% and decreased HCP levels to 345 ± 25 ppm. The overall virus recovery in these chromatography steps was 52.7%. SDS-PAGE of the purified sample showed a band with molecular mass of 56 kDa, thus consistent with the virus envelope protein (E) and corresponding to 96.7% of identified proteins. A Western blot stained with an antibody against the E protein showed a single band, confirming the identity of the sample.

D. D. Sewu, D. Lee, Hai Nguyen Tran et al.

Abstract The effect of bentonite-mineral co-pyrolysis in amounts of 5%, 10%, and 20% with macroalgae (Saccharina japonica; kelp) on the physicochemical property changes and dye adsorption of the bentonite/biochar composite was investigated. Mathematical relations to assess the contribution of mineral and biochar components of the bentonite/biochar composite on cationic, crystal violet (CV) and anionic, Congo red (CR) dye uptake were first developed via comparison with bentonite/biochar blends from stand-alone pyrolysis of kelp and bentonite. Results demonstrated that bentonite was successfully loaded into the biochar matrix, increased mesoporosity (2.67–12.7 nm), and simultaneously enhanced bio-oil (by 7.4%–35%) and biochar yields (by 6.0%–13.6%). The carbon sequestration potential increased by 27% on co-pyrolysis with 5% bentonite with an adsorption capacity value amongst the highest for CV (1275 mg/g); dominated by chemisorption. Mathematical derivations and calculations showed that co-pyrolysis enhanced adsorption capacity contribution of bentonite ( f q , P y B , c o > 0) on both dyes. Synergy comparison (rq,co/sp) between bentonite/biochar composites from the co-pyrolysis and stand-alone pyrolysis were comparable on CR and CV with 20% bentonite but superior for co-pyrolysis (rq,co/sp=1.79), on CR adsorption with 10% bentonite. Bentonite/biochar composite thus harbor potential as an effective wastewater treatment and carbon sequestration tool.

Anvesha Amaravati, Saad Bin Nasir, Justin Ting et al.

Reinforcement learning (RL) is a bio-mimetic learning approach, where agents can learn about an environment by performing specific tasks without any human supervision. RL is inspired by behavioral psychology, where agents take actions to maximize a cumulative reward. In this paper, we present an RL neuromorphic accelerator capable of performing obstacle avoidance in a mobile robot at the edge of the cloud. We propose an energy-efficient time-domain mixed-signal (TD-MS) computational framework. In TD-MS computation, we demonstrate that the energy to compute is proportional to the importance of the computation. We leverage the unique properties of stochastic networks and recent advances in Q-learning in the proposed RL implementation. The 55-nm test chip implements RL using a three-layered fully connected neural network and consumes a peak power of 690 $\mu \text{W}$ .

Bingxin Han, Xiangjun Li, Chuanshuai Sui et al.

An analog of electromagnetically induced transparency (EIT) in an asymmetric E-shaped all-dielectric metasurface was proposed and numerically demonstrated in the near infrared spectral region. The E-shaped metasurface supports a strong toroidal dipolar resonance with high quality (Q) factor, which is verified by decomposed scattered powers for multipole moments using a Cartesian coordinate system. A high transmission EIT-like optical response was achieved, and clearly interpreted by the destructive interference between the dark toroidal dipolar moment and bright magnetic dipolar mode through the asymmetric metasurface. The bandwidth of the transparency window can be easily designed by changing the asymmetric parameter of the structure. The proposed E-shaped all-dielectric metasurface gives a new way to realize toroidal dipolar response and has potential applications in bio-chemical sensing, narrowband filters, optical modulations, and slow light based devices.

Shuai Liu, Wenzhao Sun, Yujie Wang et al.

High-quality (Q)-factor silicon microdisks are promising platforms for revolutionizing bio-sensing, medical diagnoses, and frequency combs. Nevertheless, their practical applications are hindered by the regular waveguide–resonator coupling configuration, which relies on sophisticated and high-cost nanofabrication. Here, we demonstrate a simple, cost-effective, and counterintuitive mechanism to couple light into a high-Q silicon microdisk. In contrast to the evanescent coupling, the incident light is injected into silicon microdisks through the waveguides directly connected to them. The end-fire injection coefficients and Q factors of waveguide-connected microdisks are around 57% and 2×105–7×105, comparable to conventional microdisks. Importantly, the end-fire injection configuration is quite robust to fabrication deviations and can be simply realized without using electron-beam lithography. Meanwhile, their applications in monitoring nanoparticles and tiny ambient changes have also been explored. This research will route a new way to on-chip biosensors and integrated photonic circuits.

D. Damalas, A. Bletsou, Adamantia Agalou et al.

Q. Yan, C. Wan, Jian Liu et al.

Atul K. Sharma, Gaëlle Catanante, A. Hayat et al.

Poonam Sharma, Preeta Sharan

Loukia Hadjittofi, S. Charalambous, I. Pashalidis

Gérard Guez