Electrical Kinetic Model of a Hydroxylated Graphene FET Gas Sensor.

Graphene transistor sensors, with advantages such as facile surface functionalization and high sensitivity, have gained extensive research interest in gas detection applications. This study fabricated back-gated graphene transistors and employed a hydroxylation scheme for the surface functionalization of graphene. On the basis of the interaction mechanisms between gas molecules and graphene's electrical properties, a compact electrical kinetics model considering the gas-solid surface reaction of graphene transistors is proposed. The model can accurately predict the electrical kinetic performance and can be used to optimize sensor characteristics. The bias condition of a higher response can be rapidly determined. In addition, the density of hydroxyl groups on graphene is revealed to be the direction of improvement and a key factor of response. Hence, the gas detection capacity of sensors with varying densities of hydroxyl groups was assessed concerning ammonia gas, and design technology co-optimization (DTCO) is realized. Measurement results show that the sensor with 70 s of hydroxylation time has a 7.7% response under 22 ppm ammonia gas.

Dingxian pill alleviates hippocampal neuronal apoptosis in epileptic mice through TNF-α/TNFR1 signaling pathway inhibition.

ETHNOPHARMACOLOGICAL RELEVANCE: Dingxian Pill (DXP), a famous traditional Chinese medicine prescription, and has been widely proven to have positive therapeutic effects on "Xianzheng" (the name of epilepsy in ancient China). However, the anti-epileptic molecular mechanisms of DXP are not yet fully understood and remain to be further investigated. AIM OF THE STUDY: To elucidate the molecular mechanism of DXP's improvement in epileptic neuronal loss, damage and apoptosis by regulating TNF-α/TNFR1 signaling pathway. MATERIALS AND METHODS: Sixty Kunming mice were randomly divided in 6 groups: control group (equal volume of normal saline), model group (180 mg kg-1 pilocarpine hydrochloride - used to establish the epilepsy animal model), carbamazepine group (30 mg kg-1), and low, medium, and high-dose Dingxian Pill groups (4.08, 8.16, and 16.32 g kg-1, respectively - oral administration once daily for 2 weeks). Successful establishment of the epileptic mouse model was monitored with electroencephalography. Pathological changes in hippocampal tissue were analyzed with hematoxylin-eosin staining. Hippocampal neuronal apoptosis was analyzed with TUNEL staining. TNF-α, TNFR1, TRADD, FADD, and caspase-8 mRNA and protein expression levels in hippocampal tissue were analyzed with real-time quantitative polymerase chain reaction, immunohistochemistry, and Western blot, respectively. Cleaved caspase-8 protein levels in hippocampal tissue were measured with immunohistochemistry and Western blot. RESULTS: Compared to control, the model group showed an increase in continuous epileptic discharge waves on EEG, a damaged hippocampal neuron morphological structure, increased hippocampal neuronal apoptosis, and significantly increased TNF-α, TNFR1, TRADD, FADD, and caspase-8 mRNA and protein levels, and increased caspase-8 cleavage (P < 0.05). Compared to the model group, the carbamazepine group as well as the low-, medium-, and high-dose Dingxian Pill groups showed decreased epileptic discharges on EEG, an obvious hippocampal neuron morphological structure restoration, varying degrees of attenuated hippocampal neuronal apoptosis, and significantly decreased TNF-α, TNFR1, TRADD, FADD, and caspase-8 mRNA and protein levels as well as decreased caspase-8 cleavage (P < 0.05). CONCLUSIONS: Dingxian Pill exerts an anti-epileptic effect through inhibition of TNF-α/TNFR1 signaling pathway-mediated apoptosis in hippocampal neurons.

The J bs-5YP peptide can alleviate dementia in senile mice by restoring the transcription of Slc40a1 to secrete the excessive iron from brain.

INTRODUCTION: With age and ATP decrease in the body, the transcription factors hypophosphorylation weakens the transcription of Slc40a1 and hinders the expression of the iron discharger ferroportin. This may lead to iron accumulation in the brain and the catalysis of free radicals that damage cerebral neurons and eventually lead to Alzheimer's disease (AD). OBJECTIVES: To prevent AD caused by brain iron excretion disorders and reveal the mechanism of J bs-5YP peptide restoring ferroportin. METHODS: We prepared J bs-YP peptide and administered it to the senile mice with dementia. Then, the intelligence of the mice was tested using a Morris Water Maze. The ATP content in the body was detected using the ATP hydrophysis and Phosphate precipitation method. The activation of Slc40a1 transcription was assayed with ATAC seq and the ferroportin, as well as the phosphorylation levels of Ets1 in brain were detected by Western Blot. RESULTS: The phosphorylation level of Ets1in brain was enhanced, and subsequently, the transcription of Slc40a1 was activated and ferroportin was increased in the brain, the levels of iron and free radicals were reduced, with the neurons protection, and the dementia was ultimately alleviated in the senile mice. CONCLUSION: J bs-5YP can recover the expression of ferroportin to excrete excessive iron in the brain of senile mice with dementia by enhancing the transcription of Slc40a1 via phosphorylating Ets1, revealing the potential of J bs-5YP as a drug to alleviate senile dementia.

Genomic characterization of two new viruses infecting Ageratum conyzoides in China.

Two new RNA viruses were identified in Ageratum conyzoides in China using high-throughput sequencing, and their genome sequences were determined using PCR and rapid amplification of cDNA ends. The new viruses, which have positive-sense, single-stranded RNA genomes, were provisionally named "ageratum virus 1" (AgV1) and "ageratum virus 2" (AgV2). AgV1 has a genome of 3,526 nucleotides with three open reading frames (ORFs) and shares 49.9% nucleotide sequence identity with the complete genome of Ethiopian tobacco bushy top virus (genus Umbravirus, family Tombusviridae). The genome of AgV2 consists of 5,523 nucleotides and contains five ORFs that are commonly observed in members of the genus Enamovirus of the family Solemoviridae. Proteins encoded by AgV2 exhibited the highest amino acid sequence similarity (31.7-75.0% identity) to the corresponding proteins of pepper enamovirus R1 (an unclassified enamovirus) and citrus vein enation virus (genus Enamovirus). Based on their genome organization, sequence, and phylogenetic relationships, AgV1 is proposed to be a new umbra-like virus of the family Tombusviridae, and AgV2 is proposed to be a new member of the genus Enamovirus of the family Solemoviridae.

The bs-YHEDA peptide protects the brains of senile mice and thus recovers intelligence by reducing iron and free radicals.

Iron accumulates in the brain with age and catalyzes free radical damage to neurons, thus playing a pathogenic role in Alzheimer's disease (AD). To decrease the incidence of AD, we synthesized the iron-affinitive peptide 5YHEDA to scavenge the excess iron in the senile brain. However, the blood-brain barrier (BBB) blocks the entrance of macromolecules into the brain, thus decreasing the therapeutic effects. To facilitate the entrance of the 5YHEDA peptide, we linked the low-density lipoprotein receptor (LDLR)-binding segment of ApoB-100 to 5YHEDA (named "bs-YHEDA"). The results of intravenous injections of bs-5YHEDA into senescent mice demonstrated that bs-YHEDA entered the brain, increased ferriportin levels, reduced iron and free radical levels, decreased the consequences of neuronal necrosis and ameliorated cognitive disfunction without kidney or liver damage. bs-5YHEDA is a safe iron and free radical remover that potentially alleviates aging and Alzheimer's disease.

High Incidence of Axillary Web Syndrome among Breast Cancer Survivors after Breast Reconstruction.

OBJECTIVE: The aim of this study was to identify if breast reconstruction is a surgical risk factor for axillary web syndrome (AWS) in breast cancer (BC) patients. METHODS: The data of 207 patients who have been diagnosed with unilateral BC and who had mastectomy and lymph node dissection were retrospectively reviewed. Information of their clinical and pathological data, whether they had immediate -reconstruction and intraoperative radiotherapy, surgical methods, and postoperative complications during the 3 months after their surgery (AWS, lymphedema, seroma, and myofascial adhesion) were collected, and the incidence of AWS was compared between different surgical methods. RESULTS: The overall incidence of AWS was 48.8% in 207 patients. Of the 22 patients who received reconstruction, 19 developed AWS, yielding an incidence of 86%. Multivariate logistic regression modeling showed that patients who underwent reconstruction had a significantly higher incidence of AWS (odds ratio, 4.74), as did patients with postoperative complication of myofascial adhesion (odds ratio, 7.07). CONCLUSIONS: BC survivors after breast reconstruction are susceptible to AWS, and there is a significant association between myofascial adhesion and AWS. Our results can stimulate further investigation and provide an evidence base for the development of educational guidance for patients who plan to undergo breast reconstruction.

Nicotinic Acetylcholine Receptor Alpha7 Subunit Mediates Vagus Nerve Stimulation-Induced Neuroprotection in Acute Permanent Cerebral Ischemia by a7nAchR/JAK2 Pathway.

BACKGROUND The role of nicotinic acetylcholine receptor alpha7 subunit (a7nAchR) in the treatment of acute cerebral ischemia by VNS has not been thoroughly clarified to date. Therefore, this study aimed to investigate the specific role of a7nAchR and explore whether this process is involved in the mechanisms of VNS-induced neuroprotection in rats undergoing permanent middle cerebral artery occlusion (PMCAO) surgery. MATERIAL AND METHODS Rats received a7nAChR antagonist (A) or antagonist placebo injection for control (AC), followed by PMCAO and VNS treatment, whereas the a7nAChR agonist (P) was utilized singly without VNS treatment but only with PMCAO pretreatment. The rats were randomly divided into 6 groups: sham PMCAO, PMCAO, PMCAO+VNS, PMCAO+VNS+A, PMCAO+VNS+AC, and PMCAO+P. Neurological function and cerebral infarct volume were measured to evaluate the level of brain injury at 24 h after PMCAO or PMCAO-sham. Moreover, the related proteins levels of a7nAChR, p-JAK2, and p-STAT3 in the ischemic penumbra were assessed by Western blot analysis. RESULTS Rats pretreated with VNS had significantly improved neurological function and reduced cerebral infarct volume after PMCAO injury (p<0.05). In addition, VNS enhanced the levels of a7nAchR, p-JAK2, and p-STAT3 in the ischemic penumbra (p<0.05). However, inhibition of a7nAchR not only attenuated the beneficial neuroprotective effects induced by VNS, but also decreased levels of p-JAK2 and p-STAT3. Strikingly, pharmacological activation of a7nAchR can partially substitute for VNS-induced beneficial neurological protection. CONCLUSIONS These results suggest that a7nAchR is a pivotal mediator of VNS-induced neuroprotective effects on PMCAO injury, which may be related to suppressed inflammation via activation of the a7nAchR/JAK2 anti-inflammatory pathway.

Antimicrobial efficiency of PAA/(PVP/CHI) erodible polysaccharide multilayer through loading and controlled release of antibiotics.

The adhesion of bacteria and subsequent formation of biofilm on the surface of implants greatly affect the long-term use of the implants. The low molar mass gentamicin (GS) cations could hardly be directly incorporated into the multilayer films through alternately deposition with a polyanion. Herein, we have designed and constructed a (poly(acrylic acid)/(polyvinylpyrrolidone/chitosan))n ((PAA/(PVP/CHI))n) multilayer films through layer-by-layer self-assembly method. Through increasing the pH to destroy hydrogen bonding between PAA and PVP, PVP released into the solution and GS simultaneously combined with PAA through electrostatic interactions. The loading dosage of GS into the (PAA/(PVP/CHI))10 multilayer film was up to 153.84±18.64µg/cm2 and could be precisely tuned through changing the thickness of the films. The release behaviour of GS in phosphate buffer saline could also be regulated through thermal cross-linking of the films. The drug-loaded multilayer films displayed efficient against three kinds of Gram-positive and three kinds of Gram-negative bacteria and one kind of fungi, and good biocompatibility towards human lens epithelial cells. GS-loaded multilayer films-coated polydimethylsiloxane (PDMS) were compared with pristine PDMS in the rabbit subcutaneous S. aureus infection model. The antimicrobial-coated implants yielded a much lower degree of infections than pristine implants at day seven.

Fabrication of nonfouling, bactericidal, and bacteria corpse release multifunctional surface through surface-initiated RAFT polymerization.

Infections after surgery or endophthalmitis are potentially blinding complications caused by bacterial adhesion and subsequent biofilm formation on the intraocular lens. Neither single-function anti-adhesion surface nor contacting killing surface can exhibit ideal antibacterial function. In this work, a novel (2-(dimethylamino)-ethyl methacrylate-co-2-methacryloyloxyethyl phosphorylcholine) (p (DMAEMA-co-MPC)) brush was synthesized by "grafting from" method through reversible-addition fragmentation chain transfer polymerization. 1-Bromoheptane was used to quaternize the p (DMAEMA-co-MPC) brush coating and to endow the surface with bactericidal function. The success of the surface functionalization was confirmed by atomic force microscopy, water contact angle, and spectroscopic ellipsometry. The quaternary ammonium salt units were employed as efficient disinfection that can eliminate bacteria through contact killing, whereas the 2-methacryloyloxyethyl phosphorylcholine units were introduced to suppress unwanted nonspecific adsorption. The functionalized poly(dimethyl siloxane) surfaces showed efficiency in reducing bovine serum albumin adsorption and in inhibiting bacteria adhesion and biofilm formation. The copolymer brushes also demonstrated excellent bactericidal function against gram-positive (Staphylococcus aureus) bacteria measured by bacteria live/dead staining and shake-flask culture methods. The surface biocompatibility was evaluated by morphology and activity measurement with human lens epithelial cells in vitro. The achievement of the p (DMAEMA+-co-MPC) copolymer brush coating with nonfouling, bactericidal, and bacteria corpse release properties can be used to modify intraocular lenses.

Development of antibacterial and high light transmittance bulk materials: Incorporation and sustained release of hydrophobic or hydrophilic antibiotics.

Infection associated with medical devices is one of the most frequent complications of modern medical biomaterials. Bacteria have a strong ability to attach on solid surfaces, forming colonies and subsequently biofilms. In this work, a novel antibacterial bulk material was prepared through combining poly(dimethyl siloxane) (PDMS) with either hydrophobic or hydrophilic antibiotics (0.1-0.2 wt%). Scanning electron microscopy, water contact angle and UV-vis spectrophotometer were used to measure the changes of surface topography, wettability and optical transmission. For both gentamicin sulfate (GS) and triclosan (TCA), the optical transmission of the PDMS-GS and PDMS-TCA blend films was higher than 90%. Drug release studies showed initial rapid release and later sustained release of GS or TCA under aqueous physiological conditions. The blend films demonstrated excellent bactericidal and sufficient biofilm inhibition functions against Gram-positive bacteria (Staphylococcus aureus, S. aureus) measured by LIVE/DEAD bacterial viability kit staining method. Kirby-Bauer method showed that there was obvious zone of inhibition (7.5-12.5mm). Cytocompatibility assessment against human lens epithelial cells (HLECs) revealed that the PDMS-GS blend films had good cytocompatibility. However, the PDMS-TCA blend films showed certain cytotoxicity against HLECs. The PDMS-0.2 wt% GS blend films were compared to native PDMS in the rabbit subcutaneous S. aureus infection model. The blend films yielded a significantly lower degree of infection than native PDMS at day 7. The achievement of the PDMS-drug bulk materials with high light transmittance, excellent bactericidal function and good cytocompatibility can potentially be widely used as bio-optical materials.

Relating the variation of secondary structure of gelatin at fish oil-water interface to adsorption kinetics, dynamic interfacial tension and emulsion stability.

The objectives of this study were to quantify the relationship between secondary structure of gelatin and its adsorption at the fish-oil/water interface and to quantify the implication of the adsorption on the dynamic interfacial tension (DST) and emulsion stability. The surface hydrophobicity of the gelatin solutions decreased when the pH increased from 4.0 to 6.0, while opposite tend was observed in the viscosity of the solution. The DST values decreased as the pH increased from 4.0 to 6.0, indicating that higher positive charges (measured trough zeta potential) in the gelatin solution tended to result in higher DST values. The adsorption kinetics of the gelatin solution was examined through the calculated diffusion coefficients (Deff). The addition of acid promoted the random coil and ß-turn structures at the expense of α-helical structure. The addition of NaOH decreased the ß-turn and increased the α-helix and random coil. The decrease in the random coil and triple helix structures in the gelatin solution resulted into increased Deff values. The highest diffusion coefficients, the highest emulsion stability and the lowest amount of random coil and triple helix structures were observed at pH=4.8. The lowest amount of random coil and triple helix structures in the interfacial protein layer correlated with the highest stability of the emulsion (highest ESI value). The lower amount of random coil and triple helix structures allowed higher coverage of the oil-water interface by relatively highly ordered secondary structure of gelatin.