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11.
Effect of gas composition on spore mortality and etching during low-pressure plasma sterilization 总被引:4,自引:0,他引:4
Lerouge S Wertheimer MR Marchand R Tabrizian M Yahia L 《Journal of biomedical materials research》2000,51(1):128-135
The aim of this work was to investigate possible mechanisms of sterilization by low-temperature gas plasma: spore destruction by plasma is compared with etching of synthetic polymers. Bacillus subtilis spores were inoculated at the bottom of glass vials and subjected to different plasma gas compositions (O(2), O(2)/Ar, O(2)/H(2), CO(2), and O(2)/CF(4)), all known to etch polymers. O(2)/CF(4) plasma exhibited much higher efficacy than all other gases or gas mixtures tested, with a more than 5 log decrease in 7.5 min, compared with a 2 log decrease with pure oxygen. Examination by scanning electron microscopy showed that spores were significantly etched after 30 min of plasma exposure, but not completely. We speculate about their etch resistance compared with that of synthetic polymers on the basis of their morphology and complex coating structure. In contrast to so-called in-house plasma, sterilization by Sterrad(R) tended to increase the observed spores' size; chemical modification (oxidation), rather than etching, is believed to be the sterilization mechanism of Sterrad(R). 相似文献
12.
Increasing evidence suggests that oxidative and nitrosative stress play an important role in regulation of cardiac myocyte growth and survival. The cardiovascular system is continuously exposed to both reactive oxygen species (ROS) and nitrogen species (RNS), collectively termed reactive inflammatory species (RIS), and imbalances between the enzymes that regulate their bioavailability are associated with cardiac hypertrophy and the pathogenesis of cardiomyopathies, myocardial infarction and heart failure. It is now clear that RIS act as critical regulators of cardiac myocyte hypertrophy and apoptosis through control of redox-sensitive signaling cascades, such as tyrosine kinases and phosphatases, protein kinase C, and mitogen-activated protein kinases. This review will focus on the mechanisms by which ROS/RNS modulate cardiac myocyte growth and apoptosis induced by neurohormones and cytokines, and will discuss evidence for a role in the pathophysiology of heart failure. 相似文献
13.
H. Triki D. Rezig O. Bahri N. Ben Ayed A. Ben Yahia A. Sadraoui S. Ayed 《Clinical microbiology and infection》2007,13(2):176-182
This study reports the genetic characteristics of coxsackievirus A24 isolates from Tunisia, including a coxsackievirus A24 variant (CVA24v) that caused an outbreak of acute haemorrhagic conjunctivitis (AHC) between September and November 2003. The virus genome was detected by PCR from conjunctival swabs obtained from patients with AHC. Four virus isolates were obtained from PCR-positive samples and were serotyped by sequence analysis of the VP1 and VP4 genomic region and by seroneutralisation. Phylogenetic analysis of the VP1, VP4 and 3C genomic regions was performed. Other Tunisian CVA24 isolates from paralytic cases and healthy individuals were also amplified, sequenced and included in the phylogenetic analysis. The epidemic strain belonged to the CVA24 serotype. Phylogenetic analysis of the 3C region of the genome revealed a strong relationship between the Tunisian epidemic strain and strains that caused outbreaks in Korea (2002) and Guadeloupe and French Guiana (2003). Phylogenetic analysis of the VP1 and VP4 regions showed a clear distinction between serotype CVA24 isolates from conjunctivitis and non-conjunctivitis cases. This is the first study to report an outbreak of AHC caused by CVA24v in the North African region. 相似文献
14.
The present study compared concentration camp survivors and controls from the same ethnic and religious background on two variables: guilt feelings in everyday life and locus of control. No significant differences were found between survivors and controls. As for sex differences, it was found that women expressed significantly more guilt than men in "behaviors contrary to moral or ethical principles" and men were significantly more internal than women. The implications of these findings were discussed. 相似文献
15.
Simone Eckstein Rosina Ehmann Abderraouf Gritli Houcine Ben Yahia Manuel Diehl Roman Wlfel Mohamed Ben Rhaiem Kilian Stoecker Susann Handrick Mohamed Ben Moussa 《Emerging infectious diseases》2021,27(7):1964
Free-roaming camels, especially those crossing national borders, pose a high risk for spreading Middle East respiratory syndrome coronavirus (MERS-CoV). To prevent outbreaks, active surveillance is necessary. We found that a high percentage of dromedaries in Tunisia are MERS-CoV seropositive (80.4%) or actively infected (19.8%), indicating extensive MERS-CoV circulation in Northern Africa. 相似文献
16.
本研究对人胸腰段脊柱的粘弹特性作了观察,对两组40~85岁的人体胸腰椎标本作了单轴拉伸断裂试验。根据解剖学纤维方向(即尾内侧和尾外侧方向)来选择两组标本。以五种不同的应变速率来判断标本的生物力学特性。获得每组标本的最大断裂应力、应变和杨氏模量。结果表明,两种解剖方向之间各种生物力学参数均无显著差异。然而,实验发现最大断裂应力、应变和杨氏模量随应变速率增加而增加。应变速率大于3/秒,则断裂应变和杨氏模量保持不变,提示已达到上限。 相似文献
17.
The ethereal extract of AJUGA IVA (L.) S CHREB. roots, yielded 4 ecdysones. Three were proved to be cyasterone, makisterone A and ecdysterone, by using UV, IR, MS spectral methods and comparison with standard samples. Spectral data indicate that the fourth ecdysone is similar to cyasterone but having an additional hydroxy group in the side-chain. The chromatographic pattern of ecdysone content in roots, stems and leaves is presented as well as a rapid and simple Semiquantitative method for their estimation. The roots had the highest total content (0.381%). 相似文献
18.
Shigeto Taniyama Osamu Arakawa Masamitsu Terada Sachio Nishio Tomohiro Takatani Yahia Mahmud Tamao Noguchi 《Toxicon》2003,42(1):29-33
A clone of toxic dinoflagellate Ostreopsis sp. and six specimens of a parrotfish Scarus ovifrons were collected in October 1997 at Tokushima Prefecture, Japan. Ostreopsis sp. was cultured in ESM medium for 16 days, and after rearing the cell pellet (about 4.0x10(5) cells) was extracted with 50% methanol, partitioned between an aqueous layer and 1-butanol layer, and biochemically tested. Similarly, the crude toxin from S. ovifrons was extracted, and tested. The mice injected with each 1-butanol layer from Ostreopsis sp. and S. ovifrons showed the common symptoms of convulsion, drowsiness and collapse, and died within 48 h. The lethal potency of Ostreopsis sp. was calculated to be 1.0x10(-4) MU/cell. All specimens of S. ovifrons were found to be toxic, where the highest potency was determined as 2 MU/g in muscle of one specimen. After being injected with toxins, the serum creatine phosphokinase levels of mice were found to be elevated. Toxins from Ostreopsis sp. and S. ovifrons showed delayed haemolytic activity with mouse and human erythrocytes, which was inhibited by an anti-palytoxin (PTX) antibody antibody and ouabain. Toxins from Ostreopsis sp. and S. ovifrons thus resembled each other, and strongly suggested to be PTX or its akin substance. Additionally, a considerable number of adherent Ostreopsis sp. was found in the gut contents of S. ovifrons during the heavy occurrence of Ostreopsis sp. in October 1997 at Tokushima Prefecture. From the above results, it can be strongly postulated that the dinoflagellate Ostreopsis sp. is the origin of PTX which is sequestered by the parrotfish S. ovifrons through food chain. 相似文献
19.
Nefati Kiylioglu Nezih Meydan Sabri Barutca Ali Akyol 《Journal of gastrointestinal cancer》2003,34(2-3):135-137
Subacute sensory neuronopathy is a paraneoplastic syndrome, which occurs mostly in lung, breast, ovarian malignancies and lymphoma. A 75-yr-old woman who was at the twentieth month of her postoperative follow-up owing to colon adenocarcinoma admitted with subacute sensory neuronopathy. Six months later from the first, neuropathic symptoms liver metastases developed. To the best of our literature review subacute sensory neuronopathy as a preceding sign of recurrence in colon adenocarcinoma has not previously been reported. We conclude that, in the case of subacute sensory neuronopathy without an obvious underlying etiological factor, an occult malignity should always be researched in clinical practice. 相似文献
20.