Biomorphic porous graphitic carbon for electromagnetic interference shielding

Using a kind of plant biomass (coconut shell) as template and carbon precursor, we prepare biomorphic porous carbon materials for electromagnetic interference shielding application. The carbon frameworks of the porous carbon materials are modified by in situ formation of graphitic nanostructures in a catalytic graphitization process, leading to well-tailored electrical conductivity of the resultant materials. The modified porous carbon materials exhibit shielding effectiveness of 40 dB over the X-band frequency, and the shielding by absorption is as high as 91%, indicating an absorptiondominant shielding mechanism. The high absorption contribution is attributed to the coupled effects of the biomorphic porous structures and graphitic nanostructures of the porous graphitic carbon

Adaptive Backstepping Control for Air-Breathing Hypersonic Vehicles with Input Nonlinearities

This paper addresses the control problem of air-breathing hypersonic vehicles subject to input nonlinearities, aerodynamic uncertainties and flexible modes. An adaptive backstepping controller and a dynamic inverse controller are developed for the altitude subsystem and the velocity subsystem, respectively, where the former eliminates the problem of “explosion of terms” inherent in backstepping control. Moreover, a modified smooth inverse of the dead-zone is proposed to compensate for the dead-zone effects and reduce the computational burden. Based on this smooth inverse, an input nonlinear pre-compensator is designed to handle input saturation and dead-zone nonlinearities, which leads to a simpler control design for the altitude subsystem subject to these two input nonlinearities. It is proved that the proposed controllers can guarantee that all closed-loop signals are bounded and the tracking errors converge to an arbitrarily small residual set. Simulation results are carried out to demonstrate the effectiveness of the proposed control scheme

Hydroxylation of recombinant human collagen type I alpha 1 in transgenic maize co-expressed with a recombinant human prolyl 4-hydroxylase

<p>Abstract</p> <p>Background</p> <p>Collagens require the hydroxylation of proline (Pro) residues in their triple-helical domain repeating sequence Xaa-Pro-Gly to function properly as a main structural component of the extracellular matrix in animals at physiologically relevant conditions. The regioselective proline hydroxylation is catalyzed by a specific prolyl 4-hydroxylase (P4H) as a posttranslational processing step.</p> <p>Results</p> <p>A recombinant human collagen type I α-1 (rCIα1) with high percentage of hydroxylated prolines (Hyp) was produced in transgenic maize seeds when co-expressed with both the α- and β- subunits of a recombinant human P4H (rP4H). Germ-specific expression of rCIα1 using maize globulin-1 gene promoter resulted in an average yield of 12 mg/kg seed for the full-length rCIα1 in seeds without co-expression of rP4H and 4 mg/kg seed for the rCIα1 (rCIα1-OH) in seeds with co-expression of rP4H. High-resolution mass spectrometry (HRMS) analysis revealed that nearly half of the collagenous repeating triplets in rCIα1 isolated from rP4H co-expressing maize line had the Pro residues changed to Hyp residues. The HRMS analysis determined the Hyp content of maize-derived rCIα1-OH as 18.11%, which is comparable to the Hyp level of yeast-derived rCIα1-OH (17.47%) and the native human CIa1 (14.59%), respectively. The increased Hyp percentage was correlated with a markedly enhanced thermal stability of maize-derived rCIα1-OH when compared to the non-hydroxylated rCIα1.</p> <p>Conclusions</p> <p>This work shows that maize has potential to produce adequately modified exogenous proteins with mammalian-like post-translational modifications that may be require for their use as pharmaceutical and industrial products.</p

A high-density theta burst paradigm enhances the aftereffects of transcranial magnetic stimulation: Evidence from focal stimulation of rat motor cortex

Background: Theta burst stimulation (TBS) is an efficient noninvasive neuromodulation paradigm that has been widely adopted, clinically. However, the efficacy of TBS treatment remains similarly modest as conventional 10 Hz repetitive transcranial magnetic stimulation (rTMS). Objective/hypothesis: To develop a new TBS paradigm that enhances the effects of TMS administration while maintaining high time-efficiency. Methods: We describe here a new TMS paradigm, named High-Density Theta Burst Stimulation (hdTBS). This paradigm delivers up to 6 pulses per burst, as opposed to only 3 in conventional TBS, while maintaining the inter-burst interval of 200 ms (or 5 Hz) - a critical parameter in inducing long-term potentiation. This paradigm was implemented on a TMS stimulator developed in-house; its physiological effects were assessed in the motor cortex of awake rats using a rodent specific focal TMS coil. Microwire electrodes were implanted into each rat\u27s limb muscles to longitudinally record motor-evoked potential (MEP). Four different TBS paradigms (3, 4, 5 or 6 pulses per burst, 200 s per session) were tested; MEP signals were recorded immediately before (baseline) and up to 35 min post each TBS session. Results: We developed a stimulator based on a printed-circuit board strategy. The stimulator was able to deliver stable outputs of up to 6 pulses per burst. Animal experiments (n = 15) revealed significantly different aftereffects induced by the four TBS paradigms (Friedman test, p = 0.018). Post hoc analysis further revealed that, in comparison to conventional 3-pulse TBS, 5- and 6-pulse TBS enhanced the aftereffects of MEP signals by 56% and 92%, respectively, while maintaining identical time efficiency. Conclusion(s): A new stimulation paradigm is proposed, implemented and tested in the motor cortex of awake rats using a focal TMS coil developed in the lab.We observed enhanced aftereffects as assessed by MEP, with no obvious adverse effects, suggesting the translational potentials of this paradigm

Investigation of Various Cross-Linking Methods for the Immobilization of Cytosine Arabinoside on Bacterial Magnetosomes

Bacterial magnetosomes (BMs) have emerged as potential drug delivery vehicles, possessing an iron oxide or iron sulfide core surrounded by a natural lipid membrane shell. In this study, we immobilized cytosine arabinoside (Ara-C) effectively on BMs by using various methods such as direct absorption (ABMs), and others include different cross-linkers such as genipin (GP) and glutaraldehyde (G). A well-dispersed Ara-C coupled bacterial magnetosomes resulted in significantly higher negative charge than that of naked BMs (−11.5±0.3 mV) confirming the drug loading. Out of all methods, direct absorption process led to the highest encapsulation efficiency and drug loading of 88.2±4.3% and 46.9±1.2%, respectively. These designs have shown the long-term drug release behavior without an initial burst release. Our results indicate that BMs-based nanoconjugates will potentially find widespread applications in pharmaceutical field

Prognostic changes after sudden deafness in patients with inner ear malformations characterized by LSCC: a retrospective study

IntroductionThis study aimed to investigate the clinical features and prognosis of sudden sensorineural hearing loss in patients with lateral semicircular canal (LSCC) malformation.MethodsThis study enrolled patients with LSCC malformation and sudden sensorineural hearing loss (SSNHL) who were admitted to Shandong ENT Hospital between 2020 and 2022. We collected and analyzed data on examinations of audiology, vestibular function, and imaging records of patients and summarized the clinical characteristics and prognosis of these patients.ResultsFourteen patients were enrolled. Patients with LSCC malformation was noted in 0.42% of all SSNHL cases during the same period. One patients had bilateral SSNHL and the rest had unilateral SSNHL. Of them, eight and six patients had unilateral and bilateral LSCC malformations, respectively. Flat hearing loss was noted in 12 ears (80.0%) and severe or profound hearing loss was noted in 10 ears (66.7%). After treatment, the total efficacy rate of SSNHL with LSCC malformation was 40.0%. Vestibular function was abnormal in all patients, but only five patients (35.7%) had dizziness. There were statistically significant differences in the vestibular functions between patients with LSCC malformation and matched patients without the malformation hospitalized during the same period (p &lt; 0.05).ConclusionPatients with SSNHL and LSCC malformation had flat-type and severe hearing loss and worse disease prognosis compared to those with SSNHL without LSCC malformation. Vestibular function is more likely to be abnormal; however, there was no significant difference in vestibular symptoms between patients with and without LSCC malformation. LSCC is a risk factor for the prognosis of SSNHL

Long Noncoding RNA HOTTIP Promotes Mouse Hepatic Stellate Cell Activation via Downregulating miR-148a

Background/Aims: HOTTIP is a critical modulator in human diseases including liver cancer, but its role and molecular biological mechanisms in liver fibrosis are still unclear. Methods: The expression profile of HOTTIP during the progression of liver fibrosis was detected in human liver samples and in CCl4-treated mice using qRT-PCR. The expressing sh-HOTTIP adenoviral vector was used to reduce HOTTIP levels in vivo. Dual-Luciferase Reporter Assay was performed to validate the interaction between miR-148a and HOTTIP, TGFBR1, or TGFBR2. Results: HOTTIP expressions in fibrotic liver samples and cirrhotic liver samples were significantly upregulated compared with healthy liver controls, and cirrhotic samples exhibited the highest levels of HOTTIP. Moreover, HOTTIP expressions were substantially induced in the liver tissues and hepatic stellate cells (HSC) of CCl4-treated mice. Ad-shHOTTIP delivery could alleviate CCl4- induced liver fibrosis in mice. Down-regulation of HOTTIP inhibited the viability and activation of HSCs in vitro, and HOTTIP negatively regulated miR-148a expression in HSCs. miR-148a had a negative effect on HSC activation by targeting TGFBR1 and TGFBR2. Conclusion: HOTTIP is involved in the progression of liver fibrosis by promoting HSC activation. The high level of HOTTIP downregulates miR-148a, thus to increase the level of TGFBR1 and TGFBR2 and contribute to liver fibrosis