3D Dirac semimetal supported thermal tunable terahertz hybrid plasmonic waveguides.

By depositing the trapezoidal dielectric stripe on top of the 3D Dirac semimetal (DSM) hybrid plasmonic waveguide, the thermal tunable propagation properties have been systematically investigated in the terahertz regime, taking into account the influences of the structure of the dielectric stripe, temperature and frequency. The results manifest that as the upper side width of the trapezoidal stripe increases, the propagation length and figure of merit (FOM) both decrease. The propagation properties of hybrid modes are closely associated with temperature, in that when the temperature changes in the scope of 3-600 K, the modulation depth of propagation length is more than 96%. Additionally, at the balance point of plasmonic and dielectric modes, the propagation length and FOM manifest strong peaks and indicate an obvious blue shift with the increase of temperature. Furthermore, the propagation properties can be improved significantly with a Si-SiO2 hybrid dielectric stripe structure, e.g., on the condition that the Si layer width is 5 µm, the maximum value of the propagation length reaches more than 6.46 × 105 µm, which is tens of times larger than those pure SiO2 (4.67 × 104 µm) and Si (1.15 × 104 µm) stripe. The results are very helpful for the design of novel plasmonic devices, such as cutting-edge modulator, lasers and filters.

3D Dirac semimetals-dielectric elliptical fiber supported tunable terahertz hybrid waveguide.

Based on the proposed elliptical dielectric fiber-polyethylene gap-3D Dirac semimetal (DSM) hybrid plasmonic waveguide structure, the tunable propagation characteristics have been systematically investigated in the terahertz region, taking into account the influences of the structural parameters, the modified dielectric fiber, and the 3D DSM Fermi levels. The results show that as the ratio of the elliptical semi-axis along the y-direction ay and the x-direction ax (ay/ax) increases, the hybrid mode confinement increases. The real part of the effective mode index and propagation length increase with increasing the refractive index of the elliptical fiber. The propagation length and figure of merit of the hybrid modes reach 1.56×104µm and 300, respectively. In addition, by changing the Fermi level of the 3D DSM layer, the propagation properties of the hybrid modes can also be modulated in a wide range, e.g., the modulation depth of the propagation length reaches about 71.53% if the Fermi level varies in the range of 0.03-0.15 eV. The propagation properties of the hybrid modes are enhanced significantly by utilizing the modified three elliptical fiber structures, the real part of the effective mode index, and the propagation length of the modified structure are enhanced simultaneously. The results are very helpful for understanding the tunable mechanism of the 3D DSM devices and aids the design of novel plasmonic devices, e.g., lasers, modulators, and resonators.

Progress in the study of intestinal microbiota involved in morphine tolerance.

Morphine is a widely used opioid for treatment of pain. The attendant problems including morphine tolerance and morphine dependence pose a major public health challenge. In recent years, there has been increasing interest in the gastrointestinal microbiota in many physiological and pathophysiological processes. The connectivity network between the gut microbiota and the brain is involved in multiple biological systems, and bidirectional communication between them is critical in gastrointestinal tract homeostasis, the central nervous system, and the microbial system. Many research have previously shown that morphine has a variety of effects on the gastrointestinal tract, but none have determined the function of intestinal microbiota in morphine tolerance. This study reviewed the mechanisms of morphine tolerance from the perspective of dysregulation of microbiota-gut-brain axis homeostasis, by summarizing the possible mechanisms originating from the gut that may affect morphine tolerance and the improvement of morphine tolerance through the gut microbiota.

Effects of exercise interventions on negative emotions, cognitive performance and drug craving in methamphetamine addiction.

Introduction: Methamphetamine is currently one of the most commonly used addictive substances with strong addiction and a high relapse rate. This systematic review aims to examine the effectiveness of physical activity in improving negative emotions, cognitive impairment, and drug craving in people with methamphetamine use disorder (MUD). Methods: A total of 17 studies out of 133 found from Embase and PubMed were identified, reporting results from 1836 participants from MUD populations. Original research using clearly described physical activity as interventions and reporting quantifiable outcomes of negative mood, cognitive function and drug craving level in people with MUD were eligible for inclusion. We included prospective studies, randomized controlled trials, or intervention studies, focusing on the neurological effects of physical activity on MUD. Results: Taken together, the available clinical evidence showed that physical activity-based interventions may be effective in managing MUD-related withdrawal symptoms. Discussion: Physical exercise may improve drug rehabilitation efficiency by improving negative emotions, cognitive behaviors, and drug cravings. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42024530359.

Mechanism and cellular kinetic studies of the enhancement of antioxidant activity by using surface-functionalized gold nanoparticles.

The enhanced antioxidant activity of surface-functionalized gold nanoparticles (AuNPs) synthesized by self-assembly has attracted great attention, but little is known about the mechanism behind the enhanced activity. To address this challenge, the antioxidant activity of Au@PEG3SA (i.e., surface-functionalization of spherical AuNPs with the antioxidant salvianic acid A) was used as an example to illustrate the mechanism of the enhanced activity. Evaluation of the antioxidant activity was performed in a radical-scavenging reaction between Au@PEG3SA and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. As expected, the rate constant for the reaction of Au@PEG3SA with DPPH was about nine times greater than that for the salvianic acid A monomer. A comparative analysis of the spectral characteristics of Au@PEG3SA and the salvianic acid A monomer further imply that the enhancement of the antioxidative reaction kinetics may be ascribed to the variation in the transition state for the DPPH-radical scavenging reaction through π-π stacking interactions between and among adjacent groups on the surface of Au@PEG3SA. On the other hand, the kinetic enhancement of Au@PEG3SA on reactive-oxygen-species (ROS) scavenging can be observed in living cells and in vivo, which possibly provides new insight for the bioapplication of self-assembly of surface-functionalized AuNPs.

A multifunctional cobalt-organic framework for proton conduction and selective sensing of Fe3+ ions.

Developing multifunctional metal-organic frameworks (MOFs) is a new research trend. MOFs have shown remarkable performances in both proton conduction and fluorescence sensing, but the MOFs integrating the two performances are scarce. Herein, a Co-MOF, [Co6(oba)4(Hatz)(atz)(H2O)2(µ3-OH)2(µ2-OH)]·H2O (1, H2oba = 4,4-oxybis(benzoic acid), Hatz = 5-amino-1H tetrazole), has been assembled by Co2+ ions with H2oba and Hatz ligands, providing a unique example of multifunctional MOFs with both proton conduction and fluorescence sensing performances. The framework of 1 displays a pillar-layer structure built by the oba ligand as a pillar and a layer composed of Co-clusters and atz linkers. Because large-scale single crystals of 1 were successfully synthesized, the proton conduction ability of 1 was investigated using single crystal samples. 1 exhibits highly anisotropic conduction with conductivity values of 1.1 × 10-3 S cm-1 along the [001] direction and 9.1 × 10-6 S cm-1 along the [010] direction at 55 °C and 95% RH, respectively. Meanwhile, the fluorescence sensing of 1 towards metal ions was studied in aqueous solutions. Attractively, 1 may sensitively and selectively detect Fe3+ ions in the presence of other interfering ions by fluorescence quenching.

Successful treatment of a patient with an extraordinarily large deep burn.

BACKGROUND: Treatment of extraordinarily large deep burns remains a huge clinical challenge. CASE REPORT: This article is a summary of our experience with the treatment of a patient with an extraordinarily large deep burn (99.5% TBSA and 23% fourth degree burn) by using the "microskin autografting and alloskin repeated grafting" method to close the deep burn wound because of scarcity of skin sources of the patient. CONCLUSIONS: The patient has been observed for 2 years, and is able to face the reality of life peacefully with the support of his family.

Prevention and treatment of gastrointestinal dysfunction following severe burns: a summary of recent 30-year clinical experience.

AIM: To sum up the recent 30-year experience in the prevention and treatment of gastrointestinal dysfunction in severe burn patients, and propose practicable guidelines for the prevention and treatment of gastrointestinal (GI) dysfunction. METHODS: From 1980 to 2007, a total of 219 patients with large area and extraordinarily large area burns (LAB) were admitted, who were classified into three stages according the therapeutic protocols used at the time: Stage 1 from 1980 to 1989, stage 2 from 1990 to 1995, and stage 3 from 1996 to 2007. The occurrence and mortality of GI dysfunction in patients of the three stages were calculated and the main causes were analyzed. RESULTS: The occurrence of stress ulcer in patients with LAB was 8.6% in stage 1, which was significantly lower than that in stage 1 (P < 0.05). No massive hemorrhage from severe stress ulcer and enterogenic infections occurred in stages 2 and 3. The occurrence of abdominal distension and stress ulcer and the mortality in stage 3 patients with extraordinarily LAB was 7.1%, 21.4% and 28.5%, respectively, which were significantly lower than those in stage 1 patients (P < 0.05 or P < 0.01), and the occurrence of stress ulcer was also significantly lower than that in stage 2 patients (P < 0.05). CONCLUSION: Comprehensive fluid resuscitation, early excision of necrotic tissue, staged food ingestion, and administration of specific nutrients are essential strategies for preventing gastrointestinal complications and lowering mortality in severely burned patients.

A flexible control on electromagnetic behaviors of graphene oligomer by tuning chemical potential.

In this work, we demonstrate that the electromagnetic properties of graphene oligomer can be drastically modified by locally modifications of the chemical potentials. The chemical potential variations of different positions in graphene oligomer have different impacts on both extinction spectra and electromagnetic fields. The flexible tailoring of the localizations of the electromagnetic fields can be achieved by precisely adjusting the chemical potentials of the graphene nanodisks at corresponding positions. The proposed nanostructures in this work lead to the practical applications of graphene-based plasmonic devices such as nanosensing, light trapping and photodetection.

Tissue injury by hot fluid containing nitrogen mustard.

Nitrogen mustards are analogous to sulfur mustard and have similar toxic effects on tissues. With the recent surge in terror activity, mustard could be used by terrorists. Recently a group of patients suffered from skin injury caused by hot fluid containing nitrogen mustard were treated. All the patients displayed eye symptoms such as eye pain, photophobia, excessive tearing, and blurred vision. One patient suffered from severe inhalation injury. Laboratory examination showed the decrease of white blood cell count, which may result from the loss of neutrophils. At the same time, platelets were at lower level during the first 8 days and gamma-glutamyltransferase (gamma-GT), a marker of oxidative stress, was significantly increased.

[Reconstruction and transplantation of the composite skin comprising epithelial growth factor gene-transfected keratinocytes].

OBJECTIVE: To investigate the epithelial growth factor (EGF) expression of EGF gene-transfected keratinocytes and its effect on cell proliferation after grafting. METHODS: Newborn Balb/c mouse keratinocytes and gene transfected keratinocytes were seeded on the surface of acellular dermal matrix and cocultured in different ratios as follows: 1:1, 1:3, or 1:5 1 week after culture. The composite skin was grafted onto the full-thickness wound in Balb/c mouse. Specimen was harvested at interval after grafting and underwent the immunohistochemistry staining for EGF and proliferating cell nuclear antigen (PCNA). RESULTS: Immunohistochemical staining showed EGF was expressed in the newly generated epidermis 1-2 week after grafting of the composite skin comprising Balb/c mouse keratinocytes and gene-transfected keratinocytes (at the ratio of 1:5). One week after surgery, Anti-PCNA positive basal cells were more than that in composite skin containing Balb/c mouse keratinocytes alone (P<0.01). CONCLUSION: The gene-transfected keratinocytes expresses EGF and promotes the proliferation of keratinocytes in the early stage after transplantation.

Lipschitz estimates for commutators of singular integral operators associated with the sections.

Let H be Monge-Ampère singular integral operator, [Formula: see text], and [Formula: see text]. It is proved that the commutator [Formula: see text] is bounded from [Formula: see text] to [Formula: see text] for [Formula: see text] and from [Formula: see text] to [Formula: see text] for [Formula: see text]. For the extreme case [Formula: see text], a weak estimate is given.

An energy harvesting type ultrasonic motor.

An energy harvesting type ultrasonic motor is presented in this work. The novel motor not only can drive and/or position the motion mechanism, but also can harvest and convert the vibration-induced energy of the stator into electric energy to power small electronic devices. In the new motor, the stator is a sandwich structure of two PZT rings and an elastic metal body. The PZT ring bonded on the bottom surface is used to excite the stator metal body to generate a traveling wave with converse piezoelectric effect, and the other PZT ring bonded on top surface is used to harvest and convert the vibration-induced energy of the stator into electric energy with direct piezoelectric effect. Finite element method is adopted to analyze the vibration characteristics and the energetic characteristic. After the fabrication of a prototype, the mechanical output and electric energy output abilities are measured. The maximum no-load speed and maximum output torque of the prototype are 117rpm and 0.65Nm at an exciting voltage with amplitude of 134 Vp-p and frequency of 40kHz, and the maximum harvesting output power of per sector area of the harvesting PZT is 327mW under an optimal equivalent load resistance of 6.9kΩ.

Optimization of the Fano Resonance Lineshape Based on Graphene Plasmonic Hexamer in Mid-Infrared Frequencies.

In this article, the lineshape of Fano-like resonance of graphene plasmonic oligomers is investigated as a function of the parameters of the nanostructures, such as disk size, chemical potential and electron momentum relaxation time in mid-infrared frequencies. Also, the mechanism of the optimization is discussed. Furthermore, the environmental index sensing effect of the proposed structure is revealed, and a figure of merit of 25.58 is achieved with the optimized graphene oligomer. The proposed nanostructure could find applications in the fields of chemical or biochemical sensing.

Overexpression of Hypo-Phosphorylated IκBß at Ser313 Protects the Heart against Sepsis.

IκBßis an inhibitor of nuclear factor kappa B(NF-κB) and participates in the cardiac response to sepsis. However, the role of the hypo-phosphorylated form of IκBß at Ser313, which can be detected during sepsis, is unknown. Here, we examined the effects of IκBß with a mutation at Ser313→Ala313 on cardiac damage induced by sepsis. Transgenic (Tg) mice were generated to overexpress IκBß, in which Ser-313 is replaced with alanine ubiquitously, in order to mimic the hypo-phosphorylated form of IκBß. Survival analysis showed that Tg mice exhibited decreased inflammatory cytokine levels and decreased rates of mortality in comparison to wild type (WT) mice, after sepsis in a cecal-ligation and puncture model (CLP). Compared to WT septic mice, sepsis in Tg mice resulted in improved cardiac functions, lower levels of troponin I and decreased rates of cardiomyocyte apoptosis, compared to WT mice. The increased formation of autophagicvacuoles detected with electron microscopy demonstrated the enhancement of cardiac autophagy. This phenomenon was further confirmed by the differential expression of genes related to autophagy, such as LC3, Atg5, Beclin-1, and p62. The increased expression of Cathepsin L(Ctsl), a specific marker for mitochondrial stress response, may be associated with the beneficial effects of the hypo-phosphorylated form of IκBß. Our observations suggest that the hypo-phosphorylated form of IκBß at Ser313 is beneficial to the heart in sepsis through inhibition of apoptosisand enhancement of autophagy in mutated IκBß transgenic mice.

[Debridement of burn wounds using a hydrosurgery system].

The healing process of burn wounds is strongly associated with the depth of wounds, and the depth of wounds is dependent to initial temperature and duration of contact with source of heat, infection, and secondary damage in the debridement process. On this basis, some experts present a concept of accurate debridement, which denotes removal of all necrotic tissue and at the same time protecting viable tissue for repair of raw wounds in order to maximally maintain patients' appearance and functions. A new technology of burn wound debridement--hydrosurgery system has been applied clinically. This paper summarizes the characteristics of hydrosurgery in the aspects of its technology, suitable wounds, bacterial load, amount of blood loss, and degree of pain produced during operation, and also the author's opinions regarding its efficacy to realize an accurate debridement for burn injury.

Role of p38 mitogen-activated protein kinase in lung injury after burn trauma.

This study was undertaken to evaluate the effect of SB203580, a specific p38 mitogen-activated protein (MAP) kinase inhibitor, on burn-induced lung injury as well as the release of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta in rats to characterize the role of p38 MAP kinase in lung injury after burn trauma. Sprague-Dawley rats were divided into three groups: 1) sham group, or rats who underwent sham burn; 2) control group, or rats given third-degree burns over 30% total body surface area (TBSA) and lactated Ringer solution for resuscitation; and 3) SB203580 group, or rats given burn injury and lactated Ringers solution with SB203580 inside for resuscitation. Pulmonary injury was assessed at 24 h by pulmonary capillary permeability determined with fluorescein isothiocyanate-labeled albumin and lung histologic analysis. TNF-alpha and IL-1beta protein in bronchoalveolar lavage fluid and serum were measured by enzyme-linked immunosorbent assay and p38 MAP kinase was activity determined in lung by Western blot analysis. These studies showed that significant activation of p38 MAP kinase at 24 h postburn compared with control. Burn trauma resulted in increased pulmonary capillary leakage permeability, elevated levels of TNF-alpha and IL-1beta in bronchoalveolar lavage fluid and serum, and worsened histologic condition. SB203580 inhibited the activation of p38 MAP kinase, reduced the levels of TNF-alpha and IL-1beta, and prevented burn-mediated lung injury. These data suggest that p38 MAP kinase activation is one important aspect of the signaling event that may mediate the release of TNF-alpha and IL-1beta and contributes to burn-induced lung injury.

Role of p38 mitogen-activated protein kinase in Kupffer cell secretion of the proinflammatory cytokines after burn trauma.

This study was designed to investigate the role of p38 mitogen-activated protein (MAP) kinase on Kupffer cells (KCs) secretion of proinflammatory cytokines such as tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta and hepatic injury following burn trauma. Sprague-Dawley rats were randomized into four groups: (1) sham burn rats given vehicle, (2) sham burn rats given the p38 MAP kinase inhibitor SB203580 (10mg/kg i.v., 15min and 12h after sham burn), (3) rats given a 30% total body surface area (TBSA) full-thickness burn and fluid resuscitation plus vehicle, and (4) burn rats given injury and fluid resuscitation plus SB203580. Rats from each group were killed at 24h post-burn to examine plasma aspartate transaminase (AST) and alanine transaminase (ALT) and KCs were isolated. The KCs secretion of TNF-alpha and IL-1beta and p38 MAP kinase activity (by Western blot analysis) were also examined. These studies showed by more significant activation of p38 MAP kinase in KCs harvested from burn rats than from shams. Burn trauma resulted in hepatic dysfunction and promoted KCs secretion of TNF-alpha and IL-1beta. SB203580 inhibited p38 MAP kinase activity, reduced KCs secretion of proinflammatory cytokines, and alleviated burn-mediated hepatic dysfunction. These data suggest p38 MAP kinase activation is one important aspect of the signaling event that may mediate the KCs secretion of proinflammatory cytokines TNF-alpha and IL-1beta following burn trauma.

Aggregation of the Intracellular Domain of the Human Thrombopoietin Receptor c-MPL.

Thrombopoietin (TPO) is the major cytokine which is involved in platelet production and exerts its effects via the receptor c-MPL. The yeast two-hybrid system has been used to study the aggregation of the intracellular domain of c-MPL in TPO signal transduction. First, the cDNA fragment of MPLP intracellular domain was amplified and cloned by using RT-PCR method from the total RNA of HEL cells. Then the cDNA fragment was sequenced and subcloned into two-hybrid vectors pAS2 and pGAD424, respectively, and the recombinants are named as pASMM and pGADMM. Co-transformation of these plasmids into yeast activated his3 and lacZ reporter genes, demonstrating in vivo interaction of the MPLP receptor intracellular domain itself. The aggregation may be important in TPO signal transduction.

Reconstruction and transplantation of composite skin containing keratinocytes and fibroblasts.

OBJECTIVE: To investigate the role of fibroblasts in reconstruction of composite skin, and evaluate the effect of composite skin on full-thickness skin defect. METHODS: Keratinocytes and fibroblasts were seeded on the surface of acellular dermal matrix and cultivated in vitro to reconstruct the composite skin. Adherence of keratinocytes to dermal matrix was observed. Then take rate and histological construction were investigated after the composite skin was used to cover full-thickness skin defect wound in nude mice (n = 16). RESULTS: Keratinocytes grew and proliferated to reach tho confluence on the surface of the acellular dermal matrix. Keratinocytes adhered more stablely and could not be torn down from dermal matrix in operation when few fibroblasts were seeded on the epidermal surface of the dermal matrix. After grafting, the composite skin closed the full-thickness wound in nude mouse. The total survival was achived in 10 mice (62.5%). The newly generated skin was with intact histological construction of base membrance containing laminin and type IV collagen. CONCLUSION: Composite skin could close the full-thickness wound, and fibroblasts could improve adherence of keratinocytes to dermal matrix, which should benefit the survival of composite skin.