RESUMO
The increasing numbers of infections caused by multidrug-resistant (MDR) pathogens highlight the urgent need for new alternatives to conventional antibiotics. Antimicrobial peptides have the potential to be promising alternatives to antibiotics because of their effective bactericidal activity and highly selective toxicity. The present study was conducted to investigate the antibacterial, antibiofilm, and anti-adhesion activities of different CTP peptides (CTP: the original hybrid peptide cathelicidin 2 (1-13)-thymopentin (TP5); CTP-NH2: C-terminal amidated derivative of cathelicidin 2 (1-13)-TP5; CTPQ: glutamine added at the C-terminus of cathelicidin 2 (1-13)-TP5) by determining the minimal inhibitory concentrations (MICs), minimal bactericidal concentrations (MBCs), propidium iodide uptake, and analysis by scanning electron microscopy, transmission electron microscopy, and confocal laser scanning microscopy). The results showed that CTPs had broad-spectrum antibacterial activity against different gram-positive and gram-negative bacteria, with MICs against the tested strains varying from 2 to 64 µg/mL. CTPs at the MBC (2 × MIC 64 µg/mL) showed strong bactericidal effects on a standard methicillin-resistant Staphylococcus aureus strain ATCC 43300 after co-incubation for 6 h through disruption of the bacterial membrane. In addition, CTPs at 2 × MIC also displayed effective inhibition activity of several S. aureus strains with a 40-90% decrease in biofilm formation by killing the bacteria embedded in the biofilms. CTPs had low cytotoxicity on the intestinal porcine epithelial cell line (IPEC-J2) and could significantly decrease the rate of adhesion of S. aureus ATCC 43300 on IPEC-J2 cells. The current study proved that CTPs have effective antibacterial, antibiofilm, and anti-adhesion activities. Overall, this study contributes to our understanding of the possible antibacterial and antibiofilm mechanisms of CTPs, which might be an effective anti-MDR drug candidate.
Assuntos
Catelicidinas , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Timopentina , Biofilmes/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Testes de Sensibilidade MicrobianaRESUMO
The 2019 novel coronavirus disease (COVID-19) epidemic in China has presented substantial challenges to traditional forms of mental health service delivery. This review summarizes the expert consensus on the mental health treatment and services for severe psychiatric disorders during the COVID-19 outbreak developed by the Chinese Society of Psychiatry and other academic associations. The Expert Recommendations on Managing Patients with Mental Disorders during a Serious Infectious Disease Outbreak (COVID-19) outline the appropriate measures for psychiatric hospitals or psychiatric units in general hospitals, including the delivery of outpatient, inpatient, and community mental health services. The Expert Recommendations on Internet and Telehealth in Psychiatry during Major Public Health Crises (COVID-19) describe the assessment and treatment issues of internet-based mental health services during the COVID-19 outbreak. The expert consensus recommendations provide guidance for mental health professionals in managing psychiatric services during the COVID-19 outbreak in China. The experiences from China in addressing the challenges in the management of major psychiatric disorders may be useful and relevant to other countries who are combating the COVID-19 pandemic.
Assuntos
Serviços Comunitários de Saúde Mental/organização & administração , Infecções por Coronavirus/psicologia , Infecções por Coronavirus/terapia , Transtornos Mentais/psicologia , Transtornos Mentais/terapia , Pneumonia Viral/psicologia , Pneumonia Viral/terapia , Betacoronavirus , COVID-19 , China/epidemiologia , Consenso , Humanos , Pacientes Internados , Internet , Serviços de Saúde Mental/organização & administração , Pacientes Ambulatoriais , Pandemias , SARS-CoV-2 , TelemedicinaRESUMO
In this paper, one-step air plasma treatment is successfully used for poly(dimethylsiloxane)(PDMS)-plastic chip bonding. The technique is green, cheap, and requires no other reagent other than air. Hydrocarbon plastics: polystyrene (PS), cyclic olefin copolymer (COC), and polypropylene (PP) have all been successfully bonded to PDMS irreversibly. The corresponding compressed air resistances are measured to be around 500 kPa for PDMS-PS, PDMS-COC, and PDMS-PP hybrid chips. The bondings are also of good quality even after storage under different temperatures and subject to solutions from acid to base.
RESUMO
In this study, a simple and economical fabrication technique bridging micro- and nanostructures is proposed. Glass molds with micro-nanostructures are fabricated by glass microlithography. The microlithography provides flexibility for structure design, and the glass etching contributes to transform the micro glass ridge to the nanoscale. Glass ridge structures with triangular cross sections are generated by undercutting, which coupled the isotropic character of glass and the shield effect of the top Cr layer upon HF etching. Further etching induced the height of the glass ridges to shrink from micro- to nanometres due to the edge effects. At the late etching stage, the geometrical change of the glass greatly slows down, which gives better control over the size of the glass ridge. By glass structure mold-copy, well repeatable, mechanically stable and tunable polydimethylsiloxane (PDMS) channels and cones are fabricated. Scanning electron microscopy (SEM) and laser interferometry (LI) are carried out to characterize the micro-nanostructures. To demonstrate their workability, sample preconcentration to a single nanochannel level is carried out.
Assuntos
Vidro/química , Técnicas Analíticas Microfluídicas/instrumentação , Nanoestruturas/química , Dimetilpolisiloxanos/química , Fluoresceína/química , Interferometria , LuzRESUMO
In this study, steady liquid-gas phase separation is realized by applying a hydrophobic small microchannel array (SMA) to bridge two large microchannels, one for liquid phase and one for gas phase. In this structure, a capillary pressure difference between that in the SMA and the larger channel results in a steady liquid-gas interface. The generated liquid-gas interface allows for fast gas dissolving speed. By coupling the liquid-gas interface with a one directional fluidic field, a steady dissolved gas concentration gradient (DgCG) is generated. The DgCG distribution is easily designable for linear or exponential modes, providing improved flexibility for gas participated processes on chip. To demonstrate its applicability, a CO(2) DgCG chip is fabricated and applied for screening CaCO(3) crystal growth conditions in the DgCG chip. Crystals with transitional structures are successfully fabricated, which is consistent with the CO(2) DgCG distribution.