RESUMO
AIMS: The present study aimed to isolate a potential antagonist Bacillus sp. and evaluate its capacity for controlling pathogenic Vibrio parahaemolyticus in aquaculture. METHODS AND RESULTS: Strain JK08, which showed inhibitory activity against V. parahaemolyticus VP02r, was isolated from a Penaeus vannamei pond. Based on morphological, physiological, and biochemical characteristics and phylogenetic analysis, strain JK08 was identified as Bacillus sp. Through culture condition optimization, the maximal inhibition zone diameter (18.19 ± 0.16 mm) was observed when strain JK08 was cultivated at a temperature of 30°C, pH of 7, and salinity of 20 in Luria-Bertani broth for 24 h. The inhibition zone against V. parahaemolyticus VP02r of strain JK08 (â¼7 µg, in mass of crude antimicrobial substance, per tablet) was larger than those (14-18 mm in diameter) of several commercial antibiotics (10 µg per tablet) in the in vitro antagonism assay. Liquid chromatography-tandem mass spectrometry analysis results indicated the presence of three families of lipopeptides in the antimicrobial substance: surfactin (C12-C17), iturin A (C14-C17), and fengycin A (C14-C17) and B (C17), which might be the key components contributing to the antagonistic activity of strain JK08. CONCLUSIONS: Strain JK08, which is capable of producing antibacterial lipopeptides, shows effective antagonistic activity against V. parahaemolyticus VP02r, implying its promising potential for V. parahaemolyticus control in aquaculture.
Assuntos
Bacillus , Vibrio parahaemolyticus , Filogenia , Antibacterianos/farmacologia , Lipopeptídeos/químicaRESUMO
The freshwater crayfish is capable of regenerating limbs, following autotomy, injury and predation. In arthropod species, regeneration and moulting are two processes linked and strongly regulated by ecdysone. The regeneration of crayfish limbs is divided into wound healing, blastema formation, cellular reprogramming and tissue patterning. Limb blastema cells undergo proliferation, dedifferentiation and redifferentiation. A limb bud, containing folded segments of the regenerating limb, is encased within a cuticular sheath. The functional limb regenerates, in proecdysis, in two to three consecutive moults. Rapid tissue growth is regulated by hormones, limb nerves and local cells. The TGF-ß/activin signalling pathway has been determined in the crayfish, P. fallax f. virginalis, and is suggested as a potential regulator of tissue regeneration. In this review article, we discuss current understanding of tissue regeneration in the crayfish and various crustaceans. A thorough understanding of the cellular, genetic and molecular pathways of these biological processes is promising for the development of therapeutic applications for a wide array of diseases in regenerative medicine.
Assuntos
Extremidades/fisiologia , Água Doce , Regeneração , Animais , Astacoidea , CrustáceosRESUMO
We report a cascade synthetic route to directly obtain diethyl terephthalate, a replacement for terephthalic acid, from biomass-derived muconic acid, ethanol, and ethylene. The process involves two steps: First, a substituted cyclohexene system is built through esterification and Diels-Alder reaction; then, a dehydrogenation reaction provides diethyl terephthalate. The key esterification reaction leads to improved solubility and modulates the electronic properties of muconic acid, thus promoting the Diels-Alder reaction with ethylene. With silicotungstic acid as the catalyst, nearly 100% conversion of muconic acid was achieved, and the cycloadducts were formed with more than 99.0% selectivity. The palladium-catalyzed dehydrogenation reaction preferentially occurs under neutral or mildly basic conditions. The total yield of diethyl terephthalate reached 80.6% based on the amount of muconic acid used in the two-step synthetic process.
RESUMO
OBJECTIVE: To explore the usefulness of head-space gas chromatography for the determination of methanol and ethanol in Haikesu I,a raw material of artificial musk. METHODS: The determination was performed on HP-5(30 m×0.53 mm,5 Μm)capillary column with an hydrogen flame ionization detector. The solvent was dimethyl sulfoxide and the internal standard was acetone. The injector temperature and the detector temperature were controlled at 180 â and 250 â,respectively. The carrier gas was nitrogen. The containers of head-space injector were preheated at 90 â for 15 minutes. The column temperature was programmed raised,which achieved baseline separation of the components. RESULTS: The results showed a good linear relationship for methanol and ethanol in their linearity range;and the limit of detection was 0.8 and 1.0 Μg/ml,respectively. The precision and average recoveries were satisfactory. CONCLUSION: The head-space gas chromatography is simple,rapid,and precise technique for the measurement of residual solvents in Haikesu I.
Assuntos
Cromatografia Gasosa , Medicamentos de Ervas Chinesas/química , Solventes/análise , Acetona/análise , Etanol/análise , Ionização de Chama , Metanol/análiseRESUMO
OBJECTIVE: To determine ethylacetate and petroleum ether(60-90 â)in Haikesu 2,which is one of the raw materials of artificial musk,using the head-space gas chromatography. METHODS: The determination was performed on HP-5(30 m×0.53 mm,5 Μm)capillary column with an hydrogen flame ionization detector. The solvent was dimethyl sulfoxide and the internal standard was methanol. The injector temperature and the detector temperature were controlled at 180 â and 250 â,respectively. The carrier gas was nitrogen. The containers of head-space injector were preheated at 90 â for 15 minutes. The column temperature was programmed raised,which achieved baseline separation of the components. RESULTS: The results showed a good linear relationship for ethylacetate and petroleum ether(60-90 â)in their linearity range;and the limit of detection was 0.7 and 0.3 Μg/ml,respectively. The good precision and good average recoveries were satisfactory. CONCLUSION: The head-space gas chromatography is simple,rapid,and precise technique for the measurement of residual solvents in Haikesu 2.
Assuntos
Cromatografia Gasosa , Medicamentos de Ervas Chinesas/química , Solventes/análise , Acetatos/análise , Ácidos Graxos Monoinsaturados/química , Ionização de ChamaRESUMO
The sustainable production of catechol derivatives is a challenging task. Catechyl (C) and guaiacyl (G) lignins coexisting in waste tung nutshells are promising feedstocks to form valuable catechol derivatives, but the depolymerization of C/G lignin typically involves a catalytic reductive process that cannot produce these oxidized aromatic chemicals. Herein, we demonstrated that the sustainable production of catechol derivative aldehydes and acids from C/G lignin could be achieved through a heterogeneous copper-catalyzed oxidative process. Under optimized conditions, the Cu-NC-800 catalyst affords a 43.5 mg g-1 yield (8.9 wt%, based on Klason lignin) of aromatic aldehydes (protocatechuic aldehyde, vanillin) and acids (protocatechuic acid, vanillic acid). XRD and XPS analyses showed that CuO and Cu2O may be the active species during the heterogeneous oxidation of the Cu-NC-800 catalyst. This study opens new opportunities for the sustainable production of catechol derivatives from C/G-type lignin.
RESUMO
Background: Glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is a common bone and joint disease. There is currently a lack of effective treatment for GIONFH, and the disease progression may lead to total hip arthroplasty (THA). The exact mechanism of GIONFH pathogenesis remains unsettled, and emerging evidence indicates that the overactivation of osteoclasts plays a pivotal role in the occurrence and progression of this condition. Our previous study has shown that cycloastragenol (CAG), a triterpenoid saponin with multiple bioactivities, is a natural osteoclast inhibitor and has a protective effect on bone loss. However, its effect on GIONFH remains unclear. Methods: In this study, methylprednisolone (MPS) (20 mg/kg) was administered via gluteal muscle injection to female Sprague-Dawley (SD) rats to induce GIONFH, and different doses of CAG (5 and 15 mg/kg) were dispensed intraperitoneally for intervention. Micro-CT screening and angiography were applied to determine the shaping of necrotic lesions, the loss of trabecular bone, and the change in the local blood supply. The molecular mechanism was established by Real-time qPCR and Western blotting. Hematoxylin and eosin (H&E) staining was performed to identify empty lacunae in the femoral head. Results: CAG treatment shanked the necrotic lesion area, inhibited the trabecular bone loss, and improved the local blood supply in the femoral head. In addition, CAG medication lowered the ratio of Tnfsf11 (encoding RANKL) to Tnfrsf11b (encoding OPG) and the expression of osteoclast-specific genes, including Acp5 and Ctsk. Consistently, CAG treatment exhibited a dose-dependent weakening effect on the expression of osteoclastogenesis and bone resorption-related proteins, including TRAP, CTSK, and MMP9. CAG addition also alleviated the occurrence of empty lacunae in the subchondral region. Conclusion: Our discoveries demonstrate that CAG is a potential option for hip preservation therapy in GIONFH patients. Translational potential of this article: The protective effect of CAG on rats with GIONFH can be translated into clinical use.
RESUMO
We report the first observation of room-temperature quantum-confined photoluminescence (PL) from low-dimensional Ge(1-x)Sn(x)/Ge superlattices (SLs) up to a high Sn content of 6.96%. Both direct and indirect emissions associated with the interband transitions between minibands in the conduction bands and valence band were observed at room temperature. As the Sn content is increased, the energy difference between the lowest direct and indirect transitions is reduced, indicating an effective modification of the band structure desired for optoelectronics. The integrated PL intensity ratio of direct to indirect recombinations is significantly enhanced with increasing Sn content due to the reduced Γ-L energy separation and quantum confinement effect. Those results suggest that Sn-based low-dimensional structures are promising material for efficient Si-based lasers.
RESUMO
Lignin valorization to biobased polyphenols antioxidants is increasingly attractive in the modern industry due to their inherent phenolic structures. Herein, lignin-derived polyphenols with enhanced antioxidant activities were prepared from the most available technical lignin including organosolv lignin (OL), alkali lignin (AL), and enzyme lignin (EL) by iodocyclohexane (ICH) chemical demethylation. The structural evolution of lignin indicated that the CAr-OCH3 group and the CAr-O-Calkyl side-chain could be effectively transformed into the CAr-OH group, resulting in a significant increase of the phenolic-OH content and a slight decrease of the molecular weight. The 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) scavenging activity was in the order of ICHOL-24 > ICHAL-24 > ICHEL-24 ≈ FA > BHT, and the IC50 value of ICHOL-24 was 0.56 times lower than that of BHT. The structure-activity relationship demonstrated the activities were quasi-linearly related to phenolic-OH contents and could be affected by molecular weights. The H/G/S proportions of lignin could be an indicator for accurate screening of efficient lignin-derived polyphenols antioxidants (LPA). It was preliminarily estimated to have economic feasibility for producing LPA from technical lignin by demethylation compared with synthetic or natural antioxidants. This work will help to develop efficient biobased antioxidants for lignin valorization.
Assuntos
Antioxidantes , Lignina , Antioxidantes/química , Lignina/química , Polifenóis , Relação Estrutura-Atividade , Fenóis/química , DesmetilaçãoRESUMO
Engineering the pore structure and surface properties of the catalyst are the key to realizing the highly efficient conversion of low-concentration and high-throughput formaldehyde at room temperature. Herein, alkali-modified hierarchical porous Na-CoOx /CN material was prepared using a novel freeze-drying-pyrolysis method by employing super absorbent resin/MOF composites as templates, which generate mesopores distributed in a narrow region of 6â¼20â nm and abundant hydroxyl groups on the surface by alkali-modification. At room temperature, the Na-CoOx /CN material exhibited full conversion of low concentration (1.0â mg/m3 ) and high throughput (240,000â mL/(gcat h)) formaldehyde while also demonstrating outstanding catalytic stability under a even higher space velocity (480,000â mL/(gcat h)). In situ DRIFTS characterization revealed that the hydroxyl groups on the catalyst's surface could be consumed by oxidizing formaldehyde to intermediate species (carbonate, hydrocarbonate), which were then regenerated by Na+ and CO3 2- , contributing to the cycle of the reaction path.
Assuntos
Álcalis , Formaldeído , Formaldeído/química , Íons , Oxirredução , Porosidade , TemperaturaRESUMO
The development of high-flux, durable and completely self-cleaning membranes is highly desired for separation of massive oil/water mixtures. Herein, differently crosslinked poly(2-methacryloyloxylethyl phosphorylcholine) (PMPC) brush grafted stainless steel mesh (SSM) membranes (SSM/PMPCs) were fabricated by integrating of mussel inspired universal adhesion and crosslinking chemistry with surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET-ATRP). The durability and self-cleaning performance of the prepared SSM membranes were evaluated by separating sticky crude oil/water mixtures in a continuous recycling dead-end filtration device. The water filtration flux driven by gravity reached 60,000â¯Lâ m-2â h-1 with a separation efficiency of over 99.98%. Furthermore, zero-flux-decline was observed during a 5â¯h continuous filtration when assisted by mechanical stirring. More significantly, such a completely self-cleaning separation of the well crosslinked SSM/PMPC2 membrane under optimized flux and stirring conditions had been operated cumulatively for 190â¯h in 30 days without any additional cleaning. These significant advances are more promising for practical applications in crude oil-contaminated water treatments and massive oil/water mixture separation.
Assuntos
Petróleo , Aço Inoxidável , Biomimética , Fosforilcolina , PolimerizaçãoRESUMO
Generally, mammals are unable to regenerate complex tissues and organs however the deer antler provides a rare anomaly to this rule. This osseous cranial appendage which is located on the frontal bone of male deer is capable of stem cell-based organogenesis, annual casting, and cyclic de novo regeneration. A series of recent studies have classified this form of regeneration as epimorphic stem cell based. Antler renewal is initiated by the activation of neural crest derived pedicle periosteal cells (PPCs) found residing within the pedicle periosteum (PP), these PPCs have the potential to differentiate into multiple lineages. Other antler stem cells (ASCs) are the reserve mesenchymal cells (RMCs) located in the antlers tip, which develop into cartilage tissue. Antlerogenic periosteal cells (APCs) found within the antlerogenic periosteum (AP) form the tissues of both the pedicle and first set of antlers. Antler stem cells (ASCs) further appear to progress through various stages of activation, this coordinated transition is considered imperative for stem cell-based mammalian regeneration. The latest developments have shown that the rapid elongation of the main beam and antler branches are a controlled form of tumour growth, regulated by the tumour suppressing genes TP73 and ADAMTS18. Both osteoclastogenesis, as well as osteogenic and chondrogenic differentiation are also involved. While there remains much to uncover this review both summarises and comprehensively evaluates our existing knowledge of tissue regeneration in the deer antler. This will assist in achieving the goal of in vitro organ regeneration in humans by furthering the field of modern regenerative medicine. THE TRANSLATIONAL POTENTIAL OF THIS ARTICLE: As a unique stem cell-based organ regeneration process in mammals, the deer antler represents a prime model system for investigating mechanisms of regeneration in mammalian tissues. Novel ASCs could provide cell-based therapies for regenerative medicine and bone remodelling for clinical application. A greater understanding of this process and a more in-depth defining of ASCs will potentiate improved clinical outcomes.
RESUMO
River ecosystems are the most important resource of surface freshwater, but they have frequently been contaminated by excessive nutrient input of nitrogen (N) and phosphorus (P) in particular. An efficient and economic river water treatment technology that possesses the capacity of simultaneous N and P removal is urgently required. In this study, a solar-driven, self-sustainable electrolytic treatment was conducted in situ to intensify N and P removal from eutrophic river water. Solar panel was applied to provide the electrolysis setups with energy (voltage 10 ± 0.5 V), and the current density was controlled to be 0.06 ± 0.02 mA cm-2. Results indicated that the average removal efficiencies of total N (TN) and total P (TP) under electrolysis conditions reached 72.4 ± 11.7 and 13.8 ± 5.3 mg m-2 d-1, which were 3.7- and 4.7-fold higher compared to untreated conditions. Enhanced TN removal mainly reflected the abatement of nitrate N (NO3--N) (80.6 ± 4.1%). The formation of ferric ions through the electro-dissolution of the sacrificial iron anode improved TP removal by coprecipitation with SPS. Combined high-throughput sequencing and statistical analyses revealed that electrolysis significantly reshaped the microbial communities in both the sediment-water interface and suspended sediment (SPS), and hydrogenotrophic denitrifiers (e.g., Hydrogenophaga) were highly enriched under electrolysis conditions. These findings indicated that in situ electrolysis is a feasible and effective technology for intensified nutrient removal from river water.
Assuntos
Microbiota , Eliminação de Resíduos Líquidos , Eletrólise , Água Doce , Nitrogênio , Nutrientes , Fósforo , Rios , ÁguaRESUMO
Excessive theta (θ) frequency oscillation and synchronization in the basal ganglia (BG) has been reported in elderly parkinsonian patients and animal models of levodopa (L-dopa)-induced dyskinesia (LID), particularly the θ oscillation recorded during periods when L-dopa is withdrawn (the off L-dopa state). To gain insight into processes underlying this activity, we explored the relationship between primary motor cortex (M1) oscillatory activity and BG output in LID. We recorded local field potentials in the substantia nigra pars reticulata (SNr) and M1 of awake, inattentive resting rats before and after L-dopa priming in Sham control, Parkinson disease model, and LID model groups. We found that chronic L-dopa increased θ synchronization and information flow between the SNr and M1 in off L-dopa state LID rats, with a SNr-to-M1 flow directionality. Compared with the on state, θ oscillational activity (θ synchronization and information flow) during the off state were more closely associated with abnormal involuntary movements. Our findings indicate that θ oscillation in M1 may be consequent to abnormal synchronous discharges in the BG and support the notion that M1 θ oscillation may participate in the induction of dyskinesia.
Assuntos
Discinesias , Córtex Motor , Parte Reticular da Substância Negra , Idoso , Animais , Antiparkinsonianos , Humanos , Levodopa , Oxidopamina , Ratos , Substância NegraRESUMO
A lignin-biochar with high acidic oxygen-containing groups was produced via a facile simultaneous oxidization and carbonization of pulping lignin by using sulfuric acid for the first time. The lignin-biochars were investigated by 13C NMR, FTIR and XPS, and results demonstrated that treatment by sulfuric acid could oxidize part of aromatic ring side chain to introduce high acidic oxygen-containing group, especially carboxyl group. Their total acidic oxygen-containing groups of lignin-biochar including COOH and Ar-OH reached 8.64 mmol/g. Adsorption experiments were carried and the maximum adsorption capacity of lignin-biochar for Pb2+ reached 679 mg/g, which was significantly higher than other lignin-based or carbon adsorbents. Moreover, it could maintain high removal rate at high adsorption capacity. It also demonstrated that adsorption capability was proportional to the accessible carboxyl groups.
Assuntos
Chumbo , Lignina , Adsorção , Carvão Vegetal , OxigênioRESUMO
3D printing has been widely applied in the medical field since the 1980s, especially in surgery, such as preoperative simulation, anatomical learning and surgical training. This raises the possibility of using 3D printing to construct a neurosurgical implant. Our previous works took the construction of the burr hole ring as an example, described the process of using softwares like computer aided design (CAD), Pro/Engineer (Pro/E) and 3D printer to construct physical products. That is, a total of three steps are required, the drawing of 2D-image, the construction of 3D-image of burr hole ring, and using a 3D printer to print the physical model of burr hole ring. This protocol shows that the burr hole ring made of carbon fiber can be rapidly and accurately molded by 3D printing. It indicated that both CAD and Pro/E softwares can be used to construct the burr hole ring via integrating with the clinical imaging data and further applied 3D printing to make the individual consumables.
Assuntos
Estimulação Encefálica Profunda/instrumentação , Impressão Tridimensional , Desenho Assistido por ComputadorRESUMO
Oscillatory activities within basal ganglia (BG) circuitry in L-DOPA induced dyskinesia (LID), a condition that occurs in patients with Parkinson disease (PD), are not well understood. The aims of this study were firstly to investigate oscillations in main BG input and output structures-the dorsolateral striatum (dStr) and substantia nigra pars reticulata (SNr), respectively- including the direction of oscillation information flow, and secondly to investigate the effects of 5-HT1A/B receptor agonism with eltoprazine on oscillatory activities and abnormal involuntary movements (AIMs) characteristic. To this end, we conducted local field potential (LFP) electrophysiology in the dStr and SNr of LID rats simultaneous with AIM scoring. The LFP data were submitted to power spectral density, coherence, and partial Granger causality analyses. AIM data were analyzed relative to simultaneous oscillatory activities, with and without eltoprazine. We obtained four major findings. 1) Theta band (5-8â¯Hz) oscillations were enhanced in the dStr and SNr of LID rats. 2) Theta power correlated with AIM scores in the 180-min period after the last LID-inducing L-DOPA injection, but not with daily summed AIM scores during LID development. 3) Oscillatory information flowed from the dStr to the SNr. 4) Chronic eltoprazine reduced BG theta activity in LID rats and normalized information flow directionality, relative to that in LID rats not given eltoprazine. These results indicate that dStr activity plays a determinative role in the causal interactions of theta oscillations and that serotonergic inhibition may suppress dyskinesia by reducing dStr-SNr theta activity and restoring theta network information flow.
Assuntos
Corpo Estriado/fisiopatologia , Discinesia Induzida por Medicamentos/prevenção & controle , Levodopa/efeitos adversos , Piperazinas/farmacologia , Substância Negra/fisiopatologia , Ritmo Teta/fisiologia , Animais , Corpo Estriado/efeitos dos fármacos , Discinesia Induzida por Medicamentos/fisiopatologia , Masculino , Ratos , Substância Negra/efeitos dos fármacos , Ritmo Teta/efeitos dos fármacosRESUMO
BACKGROUND: As the bearing structure of fixation device in deep brain stimulation (DBS), burr hole ring is fixed on the skull and used in conjunction with Stimloc and plastic cap. But in patients with traumatic event, excessive movements are likely to bring strain on the anchoring system, which will finally cause the fixation device to fall off from the skull. METHOD: AutoCAD was used to construct two-dimension (2-D) images for traditional burr hole ring and innovative burr hole ring, respectively. According to the 2-D image, pro/Engineer (Pro/E) will be applied to construct the three-dimension (3-D) geometries. And then, 3-D printing technology was used to build the solid model. These two kinds of burr hole rings were divided into two groups: Innovative group (Nâ¯=â¯21) and Traditional group (Nâ¯=â¯21). Pull-out strength of these two groups of burr hole rings will be measured by manual tensile force testing machine on the full-size skull model, and the data were transmitted to the notebook in real time for recording and further analyzing. RESULT: The fixation strength of the innovative group is stronger than traditional group, pull-out strength value of traditional group and innovative group were 34.08⯱â¯1.31â¯N and 99.73⯱â¯2.14â¯N, respectively. (Pâ¯<â¯0.001). CONCLUSION: We provide an innovative burr hole ring, which can fix on the burr hole steadily. Moreover, 3-D printing technology may be suitable for personalized and customized medical treatment in the future.
Assuntos
Estimulação Encefálica Profunda/métodos , Eletrodos Implantados , Modelos Anatômicos , Impressão Tridimensional , Crânio/diagnóstico por imagem , Trepanação/métodos , Adulto , Estimulação Encefálica Profunda/instrumentação , Humanos , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/métodos , Impressão Tridimensional/instrumentação , Crânio/anatomia & histologia , Crânio/cirurgia , Técnicas Estereotáxicas/instrumentação , Trepanação/instrumentaçãoRESUMO
Efficient depolymerization of woody biomass to produce natural phenolic alcohols not only preserves the original structure of lignin, but also makes the depolymerization process atom-efficient. Here, high yield production of natural phenolic alcohols (38.7â wt %) from woody biomass has been achieved using a Ni/C catalyst in a methanol-water co-solvent. The Ni-based catalyst can efficiently etherify the Cα -OH group in lignin ß-O-4 motifs under hydrogen atmosphere, which can break the hydrogen bond between the Cß -O oxygen and the Cα -OH proton to facilitate the Cß -O cleavage. It was reported that water can also accelerate the etherification of raw lignin with methanol through inâ situ formation of acid. Our results suggest that breaking the intramolecular hydrogen bonds can accelerate the Cß -O cleavage, keeping the original structure of lignin unchanged. This work highlights the significance of structure modification in lignin depolymerization and displays a clear potential for the valorization of whole biomass.
Assuntos
Níquel/química , Fenóis/síntese química , Madeira/química , Biomassa , Catálise , Ligação de Hidrogênio , Lignanas/química , Água/químicaRESUMO
By consulting the literatures relevant with the prevention and treatment of human rabies from Tang Dynasty to Qing Dynasty, it was discovered that rabies was caused by wind toxin in mad dog injuring human being. The pathogenesis of rabies was the invasion of dog toxin into the heart. The latent period was ranged from 7 to 100 days. Acupuncture-moxibustion, bloodletting, cupping and other therapies could be used in treatment. But of those different therapies, the various moxibustion methods achieved unique efficacy on the disease.