一种大气压冷等离子体消毒器水消毒及其影响因素的研究

摘要 目的 了解一种以空气作为工作气体、大气压冷等离子体消毒器的水消毒性能及其影响因素。 方法 分别采用悬液定量杀菌试验和微孔滤膜过滤法,对该等离子体消毒器产生的以臭氧为主要杀菌因子的水消毒效果及影响因素进行观察。结果 该消毒器之水消毒组件运行30 min能将80 L污染水体中的大肠杆菌完全杀灭;对2 L染菌水消毒处理作用30 min,水温5 ℃、有机物浓度为15度时对其消毒效果有影响,水中pH值对其杀菌效果影响不明显。结论 该等离子体消毒器具有良好的水消毒效果,可在20～30 ℃、色度低于10度、pH值6.5～8.5条件下用于水的消毒处理。     

Low‐temperature plasmas at atmospheric pressure: toward new pharmaceutical treatments in medicine

This article concerns a new field covered by low‐temperature plasmas at atmospheric pressure for medical treatments. This is based on the very attractive possibility to tune and design plasmas as possible pharmaceutical products using selectively some active species (charged particles, radicals, atomic and molecular agents, UV radiations) and even electric fields self‐generated by the plasma. The delivery of active species occurs at the gaseous level. This means that there is no need for a carrier medium, and the treatment of living tissue or surface is optimal because plasmas can penetrate small pores, spread over rough surfaces, and reach both prokaryotic and eukaryotic cells. The present article gives first a review on the main low‐temperature plasma setups potentially usable for medical treatments with an emphasis on the setups as, for instance, plasma jets developed in our laboratory. Then, the present article gives a review of the current state of the art of such plasmas as pharmaceutical products or therapeutic tools in medicine with a light on a selection of forefront researches particularly in the field of chronic wounds, blood coagulation, and cancer treatment.     

Pitfalls in cefepime titration from human plasma: plasma- and temperature-related drug degradation in vitro

While developing a high-pressure liquid chromatography assay for cefepime in plasma, we observed significant drug degradation at 20 and 37 degrees C but not at 4 degrees C. This plasma-related degradation persisted after protein removal. This warrants caution regarding cefepime assays for pharmacokinetic and pharmacodynamic studies of cefepime in vitro and in vivo.     

Catalytic effect of laser-combined atmospheric pressure plasma in lowering the reduction temperature of hematite

Atmospheric pressure plasma (APP) generates highly reactive species that are useful for surface activation. We demonstrate a fast regeneration of iron oxides, that are popular catalysts in various industrial processes, using microwave-driven argon APP under ambient conditions. The surface treatment of hematite powder by the APP with a small portion of hydrogen (0.5 vol%) lowers the oxide''s reduction temperature. A near-infrared laser is used for localized heating to control the surface temperature. Controlled experiments without plasma confirm the catalytic effect of the plasma. Raman, XRD, SEM, and XPS analyses show that the plasma treatment changed the chemical state of the hematite to that of magnetite without sintering.

We report a novel method of controlling the oxidation state of hematite using microwave-driven atmospheric pressure plasma assisted by laser surface heating. The method lowers hematite''s reduction temperature and accelerates the reduction speed.     

Plasma functional polymerization of dopamine using atmospheric pressure plasma and a dopamine solution mist

By using DBD-type atmospheric pressure plasmas and a dopamine solution mist formed by a piezoelectric module, the possibility of depositing functional polymer films showing the physical and chemical characteristics of polydopamine without breaking the functional group of the dopamine has been investigated for different plasma voltages. The higher DBD voltages up to 3.0 kV decreased the functional groups such as catechol and amine (N/C ratio) relative to dopamine in the deposited polymer by increasing the dissociation of dopamine into atoms and small molecules due to higher electron energies. In contrast, the lower DBD voltages up to 1.5 kV increased the functional group and N/C ratio of dopamine in the deposited polymer by keeping the molecular structures of the dopamine due to lower electron energies. Therefore, the polymer deposited at the lower DBD voltages showed lower contact angles and higher metal absorption properties which are some of the surface modification characteristics of polydopamine. When the metal absorption properties of the polydopamine-like film deposited using the atmospheric pressure plasma of a low DBD voltage with a dopamine solution mist were compared with other metal absorbers for Cu, As, and Cr, the polydopamine-like film exhibited superior metal absorption properties. It is believed that this atmospheric pressure plasma process can be also applied to the plasma polymerization of other monomers without breaking the functional groups of the monomers.

By using atmospheric pressure plasmas and a dopamine solution mist formed by a piezoelectric module, the possibility of depositing functional films showing characteristics of polydopamine without breaking the functional group has been investigated.     

Effects of valsartan/ hydrochlorothiazide and amlodipine on ambulatory blood pressure and plasma norepinephrine levels in high-risk hypertensive patients

The efficacy and tolerability of the combination of valsartan and hydrochlorothi-azide (HCTZ) were compared with that of amlodipine in reducing ambulatory blood pressure and plasma norepinephrine levels in patients with mild to moderate hypertension and at least 1 cardiovascular risk factor. At the end of a 2-week washout period, 92 outpatients with a sitting diastolic blood pressure ≥95 and <110 mm Hg, associated with at least 1 additional risk factor, were randomly assigned to receive either valsartan 160 mg and HCTZ 12.5 mg once daily (n=46) or amlodipine 10 mg alone once daily (n=46) for 12 weeks, according to a prospective, randomized, open-label, blinded end point, parallel-group design. At the end of the washout period and after 6 and 12 weeks of active treatment, 24-hour ambulatory blood pressure monitoring was performed, and clinical blood pressure and heart rate and plasma norepinephrine levels were assessed (by high-performance liquid chromatography). Both the valsartan/HCTZ combination and amlodipine had a demonstrable antihypertensive effect, but the combination showed an antihypertensive effect significantly greater than that of amlodipine, as demonstrated by the 24-hour (P < .001), daytime (P < .001), and nighttime ambulatory blood pressure values (P < .01) and by the clinical blood pressure values at trough, which were all significantly lower. Although the trough-to-peak ratios were similar in both groups, the smoothness indexes pertaining to both systolic and diastolic pressures were significantly higher (P < .05 andP < .001, respectively) in patients receiving valsartan/HCTZ, suggesting the combination produces a more homogeneous antihypertensive effect. A significant increase in plasma norepinephrine levels was associated with amlodipine (+9% at 6 weeks, +15% at 12 weeks) but not with the valsartan/HCTZ combination. The valsartan/HCTZ combination was better tolerated than amlodipine, which was associated with a higher frequency of ankle edema. These results indicate that the combination of valsartan 160 mg and HCTZ 12.5 mg provides more sustained and homogeneous control of blood pressure than does amlodipine 10 mg in high-risk hypertensive patients, without producing reflex sympathetic activation.     

Vitamin C assisted synthesis of rGO–Ag/PANI nanocomposites for improved photocatalytic degradation of pharmaceutical wastes

A highly efficient visible light active polyaniline (PANI)/Ag composites grafted reduced graphene oxide (rGO–Ag/PANI) was prepared for the efficient photocatalytic degradation of paracetamol. The structural, morphological, and light absorption properties of the as-synthesized rGO–Ag/PANI were characterized by UV-Visible (UV-Vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Paracetamol was taken as a model water pollutant to investigate the photocatalytic degradation efficiency of the rGO–PANI/Ag nanocomposites under visible light radiation. The result shows the degradation of paracetamol to be 99.6% in the acidic medium (pH 5) and 75.76% in the basic medium (pH 9), respectively. The enhanced degradation efficiency is attributed to the synergetic effect of rGO, PANI, and Ag NPs in the nanocomposites. This synergy of the rGO–Ag/PANI is explained by the strong adsorption efficiency, charge separation, and light absorption in the visible region.

A highly efficient visible light active polyaniline (PANI)/Ag composites grafted reduced graphene oxide (rGO–Ag/PANI) was prepared for the efficient photocatalytic degradation of paracetamol.     

Direct exposure of non-equilibrium atmospheric pressure plasma confers simultaneous oxidative and ultraviolet modifications in biomolecules

Thermal plasmas and lasers are used in medicine to cut and ablate tissues and for coagulation. Non-equilibrium atmospheric pressure plasma (NEAPP) is a recently developed, non-thermal technique with possible biomedical applications. Although NEAPP reportedly generates reactive oxygen/nitrogen species, electrons, positive ions, and ultraviolet radiation, little research has been done into the use of this technique for conventional free radical biology. Recently, we developed a NEAPP device with high electron density. Electron spin resonance spin-trapping revealed ^•OH as a major product. To obtain evidence of NEAPP-induced oxidative modifications in biomolecules and standardize them, we evaluated lipid peroxidation and DNA modifications in various in vitro and ex vivo experiments. Conjugated dienes increased after exposure to linoleic and α-linolenic acids. An increase in 2-thiobarbituric acid-reactive substances was also observed after exposure to phosphatidylcholine, liposomes or liver homogenate. Direct exposure to rat liver in saline produced immunohistochemical evidence of 4-hydroxy-2-nonenal- and acrolein-modified proteins. Exposure to plasmid DNA induced dose-dependent single/double strand breaks and increased the amounts of 8-hydroxy-2''-deoxyguanosine and cyclobutane pyrimidine dimers. These results indicate that oxidative biomolecular damage by NEAPP is dose-dependent and thus can be controlled in a site-specific manner. Simultaneous oxidative and UV-specific DNA damage may be useful in cancer treatment.     

Cortisol and cortisone analysis in serum and plasma by atmospheric pressure photoionization tandem mass spectrometry

OBJECTIVES: Cortisol metabolism is controlled by 11beta-hydroxysteroid dehydrogenase (11beta-HSD) isoenzymes, which interconvert cortisol and cortisone. Accurate measurement of the cortisol and cortisone concentrations and their ratio provide useful information about 11beta-HSD activity. METHODS: Cortisol and cortisone were extracted with methyl-tert-butyl ether from 100 microl of serum or plasma. The extract was evaporated, reconstituted with mobile phase, and analyzed by tandem mass spectrometry using a photoionization interface. The transitions monitored were: m/z 363 to 121 and 363 to 97 for cortisol, 361 to 163 and 361 to 105 for cortisone. RESULTS: Within-run and between-run coefficients of variation were less than 6% and 12%; 14% and 22%; 11% and 21% for cortisol, cortisone, and their ratio, respectively. The limit of detection was 1 microg/l for cortisol and 5 microg/l for cortisone. Normal ranges for cortisol and cortisone concentration and for their ratio in plasma (n = 120) determined as the central 95% were 33-246 microg/l for cortisol, 8-27 microg/l for cortisone, and 0.081-0.301 for the cortisone/cortisol ratio. CONCLUSIONS: We developed a simple sensitive method for cortisol and cortisone analysis in plasma and serum that uses a small sample volume. The method is very specific, fast, does not have any known interference, and is useful for diagnosis of variety of disease and pathologic conditions.     

Hydroxylation and self-assembly of colloidal hydrogenated nanodiamonds by aqueous oxygen radicals from atmospheric pressure plasma jet

Plasma chemical surface modification of nanoparticles in gas–liquid type reactors enables a controllable, specific, low-cost, and environmentally friendly alternative to wet chemistry methods or thermal and dry plasma treatments. Here the atmospheric pressure radio-frequency microplasma jet (µ-APPJ) operating with 0.6% O₂ in He is used to deliver aqueous oxygen radicals (AOR) to the surface of ∼3 nm hydrogenated detonation nanodiamonds (H-DNDs) suspended in water. The AOR-treated H-DND samples are characterized by FTIR and XPS spectroscopies and by AFM and SEM imaging. The main chemical reaction mechanism is identified as the abstraction of surface hydrogen atoms by O or OH radicals and a consequent attachment of the OH group, thereby increasing concentration of alcohols, carboxyls, and aldehydes on the DND''s surface. FTIR spectra reveal also a structural re-arrangement of the surface water on the AOR-treated H-DNDs. Yet zeta-potential of AOR-treated H-DNDs still remains positive (decreases from +45 mV to +30 mV). The chemical modification gives rise to formation of nanoscale chain-like aggregates when AOR-treated H-DNDs are deposited on Si substrate.

Colloidal nanodiamonds are hydroxylated by action of plasma-supplied O atoms and undergo self-assembly to chains.     

Compliance revisited: pharmaceutical drug trials in the era of the contract research organization

Over the past decade, the management of clinical trials of pharmaceuticals has become a veritable industry, as evidenced by the emergence and proliferation of contract research organizations (CROs) that co-ordinate and monitor trials. This article focuses on work performed by one CRO involved in the introduction of new software, modelled on industrial production processes, into clinical trial practices. It investigates how this new management technique relates to the work performed in the clinic to ensure that trial participants comply with the protocol. Using an analytical distinction between 'classical' management work and invisible work, the article contextualizes the meaning of compliance in the clinic and suggests that the work involved in producing compliance should be taken into consideration by those concerned with validity of trials, as clinical trials are put under private industrial management. The article builds on participant observation at a Swedish university hospital and interviews the nurses, dieticians, doctors and a software engineer, all part of a team involved in pharmaceutical drug trials on a potential obesity drug.     

Conscious surgery: influence of the environment on patient anxiety

Title. Conscious surgery: influence of the environment on patient anxiety. Aims. This paper is a report of a study: (i) to investigate anxiety arising from the experience of the clinical environment during surgery under local/regional anaesthesia and (ii) to uncover the specific aspects patients find anxiety provoking and possibly dissuade them from opting for such anaesthesia. Background. Operating theatre staff have focused historically on conducting safe, efficient surgery with unconscious patients and not primarily on the care of ‘awake’ patients. However, with the rise in day surgery, the volume of surgery performed under local or regional anaesthesia is increasing. Method. As part of a larger study investigating anxiety in elective day surgery, a questionnaire was given to 523 patients on the day of surgery to adult patients undergoing surgery with local or regional anaesthesia between 2005 and 2007. They were asked to return this by mail 24–48 hours following surgery and 214 completed questionnaires were returned (response rate 41%). Findings. The experience of being awake, possibly feeling the surgeon's touch, seeing their body cut open or surgery being more painful than expected were anxiety‐provoking aspects. Using factor analysis, ‘intra‐operative apprehension’, ‘anaesthetic information provision’ and ‘health control’ were identified as central features. Multiple regression showed that apprehension associated with the intra‐operative experience and anaesthetic information provision were statistically significantly associated with an increase in overall level of anxiety. Conclusion. Focusing care on managing the intra‐operative experience and providing anaesthetic information in advance might help limit anxiety and expel the apparent misapprehensions associated with conscious surgery.     

Cold atmospheric pressure plasma for attenuation of SARS-CoV-2 spike protein binding to ACE2 protein and the RNA deactivation

Cold atmospheric pressure (CAP) plasma has a profound effect on protein–protein interactions. In this work, we have highlighted the deactivation of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spike protein by CAP plasma treatment. Complete deactivation of spike protein binding to the human ACE2 protein was observed within an exposure time of 5 minutes which is correlated to the higher concentration of hydrogen peroxide formation due to the interaction with the reactive oxygen species present in the plasma. On the other hand, we have established that CAP plasma is also capable of degrading RNA of SARS-CoV-2 virus which is also linked to hydrogen peroxide concentration. The reactive oxygen species is produced in the plasma by using noble gases such as helium, in the absence of any other chemicals. Therefore, it is a green process with no chemical waste generated and highly advantageous from the environmental safety prospects. Results of this work could be useful in designing plasma-based disinfection systems over those based on environmentally hazardous chemical-based disinfection and biomedical applications.

Cold atmospheric pressure (CAP) plasma for the deactivation of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spike protein binding to ACE2 protein.     

Gas-phase degradation of 2-butanethiol initiated by OH radicals and Cl atoms: kinetics,product yields and mechanism at 298 K and atmospheric pressure

Relative rate coefficients and product distribution of the reaction of 2-butanethiol (2butSH) with OH radicals and Cl atoms were obtained at atmospheric pressure and 298 K. The experiments were performed in a 480 L borosilicate glass photoreactor in synthetic air coupled to a long path “in situ” FTIR spectrometer. The rate coefficients obtained by averaging the values from different experiments were: k_OH = (2.58 ± 0.21) × 10⁻¹¹ cm³ per molecule per s and k_Cl = (2.49 ± 0.19) × 10⁻¹⁰ cm³ per molecule per s. The kinetic values were compared with related alkyl thiols and homologous alkyl alcohols, where it was found that thiols react faster with both oxidants, OH radicals and Cl atoms. SO₂ and 2-butanone were the major products identified for the reactions of 2-butanethiol with OH radicals and Cl atoms. The product yield of the reaction of 2-butanethiol and OH radicals were (81 ± 2)%, and (42 ± 1)% for SO₂ and 2-butanone, respectively. For the reactions of 2-butanethiol with Cl atom, yields of SO₂ and 2-butanone were (59 ± 2)% and (39 ± 2)%, respectively. A degradation mechanism was proposed for the pathways that leads to formation of identified products. The product distribution observed indicated that the H-atom of the S–H group abstraction channel is the main pathway for the reaction of OH radicals and Cl atoms with 2-butanethiol.

Relative rate coefficients and product distribution of the reaction of 2-butanethiol (2butSH) with OH radicals and Cl atoms were obtained at atmospheric pressure and 298 K.     

PEG hydrogel degradation and the role of the surrounding tissue environment

Poly(ethylene glycol) (PEG)‐based hydrogels are extensively used in a variety of biomedical applications, due to ease of synthesis and tissue‐like properties. Recently there have been varied reports regarding PEG hydrogel's degradation kinetics and in vivo host response. In particular, these studies suggest that the surrounding tissue environment could play a critical role in defining the inflammatory response and degradation kinetics of PEG implants. In the present study we demonstrated a potential mechanism of PEG hydrogel degradation, and in addition we show potential evidence of the role of the surrounding tissue environment on producing variable inflammatory responses. Copyright © 2013 John Wiley & Sons, Ltd.     

Non-thermal atmospheric pressure plasma as a powerful tool for the synthesis of rhenium-based nanostructures for the catalytic hydrogenation of 4-nitrophenol

Here we have presented a new method for the synthesis of Re nanostructures with defined optical, structural, and catalytic properties. The Re-based nanoparticles (NPs) were obtained using a reaction-discharge system that is unique in its class, because of its working in the high-throughput mode. Within this application, direct current atmospheric pressure glow discharge (dc-APGD) was used as a non-thermal atmospheric pressure plasma (NTAP) source, which led to the reduction of Re(vii) ions and the formation of Re nanostructures through the plasma–liquid interactions. The Re-based NPs were synthesized in a flow-mode reaction-discharge system, where their precursor solution was a flowing liquid anode (FLA) or a flowing liquid cathode (FLC). The resultant NPs were analyzed using UV/Vis absorption spectrophotometry and transmission electron microscopy (TEM), which were supported by selected area X-ray diffraction (SAED) and the energy dispersive X-ray spectroscopy (EDX). Additionally, the mechanism for the reduction of Re(vii) ions was explained by the differences in the concentrations of the selected reactive nitrogen species (RNS) and reactive oxygen species (ROS) produced by dc-APGD. It was found that the application of dc-APGD, operating in a FLA configuration (FLA-dc-APGD), resulted in the formation of ReNPs with Re⁰, while the use of dc-APGD operating in a FLC configuration (FLC-dc-APGD) led to the formation of Re oxide NPs. In the latter case, a much greater oxidizing environment was likely provided, therefore the RNS and ROS contributed to the formation of Re oxide nanostructures. The ReNPs with Re⁰ were characterized by a size of 6.02 ± 3.01 nm, and the Re oxide NPs were characterized by a size of 4.97 ± 3.82 nm. Both types of nanostructures were then employed in the catalytic hydrogenation of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Based on the results, both of the nanocatalysts effectively reduced 4-NP with an apparent rate constant (k_app) of 2.6 × 10⁻³ s⁻¹. At the same time, the catalytic activity was linked with the average size distribution of the Re nanostructures, as opposed to their morphology.

A unique reaction-discharge system was used for the production of Re-based nanoparticles (NPs) revealing enhanced catalytic activity.     

Atmospheric pressure plasma liquid assisted deposition of polydopamine/acrylate copolymer on zirconia (Y-TZP) ceramics: a biocompatible and adherent nanofilm

Polydopamine–ethylene glycol dimethacrylate copolymer is a biocompatible coating with cell adhesion promotion and antibiofilm properties. This copolymer has been successfully applied on metallic implants, such as stainless steel and titanium implants, using several deposition techniques (e.g. layer-by-layer, silane activation, chemical vapor deposition, or liquid-assisted plasma polymerization). However, its application in zirconia ceramic materials, which are widely used in dentistry and medicine, has never been described. In this work, polydopamine–ethylene glycol dimethacrylate copolymer has been deposited on ultra-smooth surfaces of yttria-stabilized zirconia discs (average roughness = 2.08 ± 0.08 nm) by using liquid-assisted atmospheric-pressure plasma-induced polymerization (LA-APPiP). After the polymerization, the nanometric coating (250 nm, measured by ellipsometry) had an average roughness of 79.85 ± 13.71 nm and water contact angle of 57.8 ± 2.2 degrees, consistent with the highly hydrophilic nature of the biocompatible copolymer, if compared to the pristine zirconia (72.7 ± 2.0 degrees). The successful covalent bonding of the copolymer with the zirconia surface, thanks to the previous activation of the substrate with oxygen plasma, was proved by X-ray photoelectron spectroscopy (XPS). The polymer composition has been investigated by XPS and Raman spectroscopies. The LA-APPiP technique has been proved to be an excellent method to produce homogenous films without the need to employ solvents and further purification steps. The new copolymer film allows the uniform growth of human osteoblast-like MG-63 cells, after 7 days of cell culture, as observed by fluorescence microscopy.

Polydopamine–ethylene glycol dimethacrylate copolymer is a biocompatible coating with cell adhesion promotion and antibiofilm properties.     

结肠CT仿真内窥镜充气方法及压力的研究

目的：探讨结肠CT仿真内窥镜较理想的充气方法和充气压力。材料和方法：8名志愿者中，男4名，女4名，最大年龄50岁，最小年龄40岁，平均44.4岁。用电脑遥控灌肠整复仪通过双腔气囊胶乳导尿管向志愿者结肠内注入气体。先行最大耐受气压CT扫描，扫描期间持续注入这个压力直到扫描结束，然后每降低7.5mmHg进行一次CT扫描，最低压力为30mmHg。结果：肛门插管用双腔气囊胶乳导尿管。CT扫描时，用持续性注入同一压力气体的方法。结肠扩张程度，在52.5mmHg，40mmHg，37.5mmHg，30mmHg 4个级别气压之间，无显著性差异。结肠充气CT扫描后，腹部不适消失时间，男女之间有显著性差异。结论：CT扫描时，持续性注入同一压力气体的方法，可以保持肠管扩张的稳定性，保证CTVE检查的顺利进行。肠管充气压力的控制，不应以患者的最大耐受为标准，应以较低的气压为妥，本研究为30mmHg。肛门插管用双腔气囊胶乳导尿管，其膨胀的气囊可以起到固定导尿管和减少导尿管与肛门间的漏气作用。CT充气扫描后，腹部不适消失时间，女性较男性为长。