26株铜绿假单胞菌对常用抗菌药物敏感性的体外研究

目的了解院内感染铜绿假单胞茵的耐药性变化情况,为临床诊治提供参考。方法收集2005年至2007年我院各科临床标本,分离培养铜绿假单胞茵并做药敏鉴定,分析其耐药性的变化。结果共检出26株铜绿假单胞茵。进行抗生素的耐药性检测,亚胺培南和哌拉西林、环丙沙星等抗生素的具有较强的抗菌作用,氨苄西林和头孢曲松为甚,其耐药率高达96.15%和84.62%。结论要加强对铜绿假单胞茵的耐药性检测并合理使用抗生素以延缓耐药菌株增加。     

ICU患者中颅脑损伤后下呼吸道感染150株病原菌耐药性分析

目的为掌握我院脑外科ICU下呼吸道感染病原菌的分布情况,确定我院的院内感染菌,了解细菌耐药现状,作此分析报告。方法将我院脑外科ICU2006～2007年下呼吸道感染的病历资料进行统计分析,将各种病原菌的耐药情况进行比较分析。结果 2年收集了90例患者的资料,共检出150株菌,分布于15个属,30个种,革兰阳性菌占8.67%,主要为葡萄球菌和肠球菌。革兰阴性菌占优势,为88.67%,集中在克雷伯杆菌,铜绿假单胞,大肠埃希菌,不动杆菌。真菌检出占2.67%。细菌耐药情况严重,MRSA的检出率为87.25%(7/8),革兰阴性菌的耐药情况也很严重。ESBL的阳性检出率克雷伯杆菌中的占31.58%(12/38),大肠埃希菌中占23.53%(4/17)。结论脑外科ICU下呼吸道感染病原菌的分布较广种类较多,革兰阴性菌占绝对优势,我院院内感染菌为肺炎克雷伯杆菌,铜绿假单胞菌,大肠埃希菌,不动杆菌。细菌耐药性很强,应重视细菌培养和药敏实验,做到合理用药。     

2003年至2010年铜绿假单胞菌的耐药性变迁及临床对策

目的调查及分析临床分离的铜绿假单胞菌的耐药性及其变迁,为临床合理用药提供依据。方法对医院2003年1月至2010年12月住院患者各种标本中分离到的铜绿假单胞菌1124株,采用20种抗菌药物进行药敏试验,并比较4年的变迁。结果分离到的铜绿假单胞菌对氨苄西林、阿莫西林/克拉维酸、氨苄西林/舒巴坦、头孢替坦、头孢唑林、呋喃妥因、磺胺甲噁唑/甲氧苄啶的耐药率均>90.00%;对碳青酶烯类美罗培南产生了51.51%的耐药率;对头孢哌酮/舒巴坦、庆大霉素、头孢匹美、头孢他啶、环丙沙星的敏感率均>60.00%;而最敏感的是妥布霉素、阿米卡星。结论铜绿假单胞菌对阿米卡星、妥布霉素敏感性最高,而对其他几种多药耐药现象严重,当引起临床重视。     

2007年我院呼吸道感染病原菌耐药性分析

目的了解我院2007年痰培养细菌的种类及耐药性。方法对我院2007年痰标本分离出的病原微生物的药敏试验结果进行回顾性统计分析。使用德灵诊断产品有限公司的Microscan微生物分析仪鉴定。结果从255份送检标本分离出细菌271株,其中革兰阳性菌占35.06%,革兰阴性菌占64.94%,分离率最高为肺炎克雷伯杆菌36株,占13.3%;其次金葡球菌27株,占10.0%;第三为铜绿假单孢菌26株,占9.6%。革兰阴性菌中敏感率最高的是亚胺培南(硫霉素),肺炎克雷伯菌的耐药率2.8%,大肠埃希氏菌耐药率5.3%,但铜绿假单胞菌和短黄杆菌耐药率相对较高分别是11.5%和为15.4%,然后是阿米卡星。革兰阳性菌金葡球菌、表皮葡萄球菌和溶血葡萄球菌中敏感率最高的是万古霉素100%,其次是利福平和四环素,耐药率最高的是青霉素和氨苄西林,以上3种细菌对它们的耐药率均是100%。结论革兰阴性菌分离率高于革兰阳性菌。革兰阴性菌耐药状况严重,敏感率最高的是亚胺培南(硫霉素)90.18%、然后依次是阿米卡星76.92%;金葡球菌、表皮葡萄球菌和溶血葡萄球菌等革兰阳性菌存在严重耐药性,敏感率最高的是万古霉素。     

经支气管镜保护性毛刷对难治性肺部感染的病原学诊断及耐药性研究

目的探讨经电子支气管镜防污染保护性毛刷(PSB)在难治性肺部感染的病原学诊断及耐药性的价值。方法对186例具有严重基础疾病临床出现肺部浸润拟诊肺部感染的患者经电子支气管应用保护性毛刷在病变部位采样作病原学诊断。结果186例采样标本分离出细菌124株,其中革兰阴性杆菌94株,以铜绿假单胞菌占优势;革兰阳性菌22株,以金黄色葡萄球菌为主,真菌8株,其中耐药菌比例升高,耐甲氧西林金葡菌比率升高明显。结论引起难治性肺部感染的病原菌以耐药假单胞菌属和金黄葡萄球菌为主;经支单套管加气管镜防污染毛刷取样诊部感染病原菌具有准确可靠等优点,是检测肺部感染病原菌的有效方法。     

铜绿假单胞菌在水体的生长特性研究及其在不同温度下生长预测模型的建立

目的:为了更好的了解铜绿假单胞菌在水体中的生长特性,并预测铜绿假单胞菌在不同温度水体中的生长情况,从而有效降低环境中潜在的铜绿假单胞菌污染风险。方法:本实验研究了铜绿假单胞菌标准菌株在不同温度下的生长情况,之后使用Richards模型、MMF模型、Gompertz模型和Logistic模型进行数据拟合,构建不同温度下的最佳模型。结果:MMF模型适用于15℃、25℃和35℃下水体环境中的铜绿假单胞菌生长模型的构建。Logistic模型可以用来模拟5℃下铜绿假单胞菌的生长模型。结论:该模型能够较好的描述铜绿假单胞菌在不同温度下的生长规律和变化特征,能够为铜绿假单胞菌在水体环境中的生长提供较为准确地预测数据。     

重症监护病房呼吸机相关性肺炎的病原菌分布及耐药性分析

目的研究重症监护病房(PICU)呼吸机相关性肺炎(VAP)病原菌分布及耐药性。方法将我院82例符合VAP诊断标准的PICU呼吸机治疗的患儿,收集其痰细菌培养阳性结果 ,进行统计分析。结果 2008年1月至2010年6月PICU符合条件的痰标本共分离病原菌187株,其中革兰阴性菌占76.5%(143株),鲍氏不动杆菌33株、大肠埃希菌30株、铜绿假单胞菌28株,其对β?内酰胺类抗菌药物有较高的耐药性;革兰阳性菌占24.5%(44株),表皮葡萄球菌(11株)、金黄色葡萄球菌(9株)除对万古霉素仍敏感外,对头孢菌素以及氨基糖苷类抗菌药物的耐药率很高。结论 PICU患儿VAP深部痰培养仍以革兰阴性菌为主,其耐药性较强。     

医院感染酵母样真菌分布及耐药性分析

目的了解医院感染酵母样真菌分布及耐药性性况,供临床借鉴。方法采用回顾性资料分析2005年4月～2006年11月间,从我院各临床标本中分离到的酵母样真菌菌种及其耐药性情况。结果从各临床标本中分离出219株酵母样真菌,其中白色念珠菌占41.5%,葡萄牙念珠菌15.1%,热带念珠菌12.4%,白珠拟酵母菌9.6%,酵母样真菌对多烯类药的两性霉素B和制毒菌素有高度敏感性,分别是97.6%和96.5%;对5-氟胞嘧啶和酮康唑敏感性低,分别是33.4%和37.9%。结论医院感染酵母样真菌主要是白色念珠菌,各种酵母样真菌对唑类各核苷类抗真菌药有不同程度耐药,应引起临床关注。     

高效石油降解菌群的构建及其耐盐性能研究

以原油降解率为目标,考察了5株石油烃降解菌对原油的降解情况,确定铜绿假单胞菌、氧化微杆菌、中间苍白杆菌3株菌接种量以体积比1∶1∶1混合后,原油降解率最高达74.16%。其中,铜绿假单胞菌、氧化微杆菌对饱和烃均有明显的降解作用,中间苍白杆菌只能够降解部分烷烃。探究了不同盐度对筛选出的3株菌的影响,结果表明,当液体培养基中盐质量浓度从10 g/L上升到50 g/L时,3株菌均能生长,随着含盐质量浓度的增加,菌株浓度依次减少,生长活性减弱,细胞膜通透性变大,细胞失水,导致细胞表面出现褶皱和凹痕,细胞壁变薄,细胞质减少,严重影响了细胞的活性。     

呼吸道感染患者痰液培养及药敏结果分析

目的监测我院呼吸道感染的病原菌变化和耐药情况,为临床合理用药提供科学依据。方法对2005年1月～2007年2月本院临床送检的痰标本进行分离培养、鉴定及进行细菌药敏试验。结果从2051份标本中分离出致病菌1557株,致病菌生长的阳性率75.91%,其中革兰阳性菌占54.01%,真菌占32.63%,革兰阴性菌占13.36%;检出率居前8位的是:白丝酵母菌292株(19.08%)、D群链球菌209株(13.42%)、无乳链球菌174株(11.18%)、化脓链球菌112株(7.19%)、表皮葡萄球菌106株(6.81%)、金黄色葡萄球菌82株(5.27%)、咽峡炎链球菌34株(2.18%)、铜绿假单胞菌27株(1.73%)、肺炎克雷伯菌27株(1.73%)。革兰阳性球菌对青霉素类、氨基糖苷类、喹诺酮类、大环内脂类抗生素敏感率较低,万古霉素的敏感率小于90%,头孢类抗生素敏感率较高。各类抗生素对革兰阴性杆菌依然保持较高的抗菌活性,多数革兰阴性杆菌对亚胺培南高度敏感。结论应根据病原菌分布及药物敏感情况科学合理地选择抗生素。     

Structure-property relationships of microfibrillar reinforced blends of linear polycondensates

Binary microfibrillar reinforced composites are obtained by melt-blending of poly(ethylene terephthalate) (PET) and polyamide 6 (PA6), as well as polyamide 66 (PA66) and PA6 (both 40/60 by wt) in the presence of a catalyst, followed by cold drawing of the bristle to about 3.5 times and annealing at 220 or 240C. The blends are studied by X-ray diffraction, scanning electron microscopy (SEM), light microscopy and static mechanical testing. SEM and light microscopy reveal different blend morphologies due to differences in the miscibility of the homopolymers: the PA66/PA6 blend is morphologically more homogeneous, than the PET/PA6 blend. Annealing at 240C results in preservation of the high orientation of PET and PA66 while the PA6 portions of the two blends are partially disoriented, much more for the PET/PA6 blend as concluded from the X-ray data. Annealing at 240C suggest also transreactions leading to the in situ generation of block copolymers in addition to the generated ones during blend mixing in the extruder which improve the compatibility of the blend components. These physical and chemical changes affect the mechanical properties of the fibrillar reinforced blends and composites. The Young's moduli (E) and tensile strength ( σ t ) of the drawn blends are 5-6 and 7-9 times higher than those of the asextruded samples. Heat treatment at 220C results in a slight (for PA66/PA6) and stronger (for PET'PA6 blend) decrease of the σ t while E remains unchanged. A stronger decrease of E in both blends and of σ t in PA66/PA6 sample has been observed after annealing at 240C. Nevertheless, E and σ t of the last samples are about 3 times higher than those for the neat PA6.     

Reduction of phytic acid concentration in protein isolates by acylation techniques

The interaction of phytic acid (PA) with proteins is dependent on the charges and conformation of the proteins and the ionic strength of the solution. Hence, changes in these parameters brought about by acylation could change the extractability, precipitation and interactions of PA with protein and minerals and consequently the PA concentration of protein isolates from phytate-containing foods. This paper summarizes studies in rapeseed and navy bean flours which demonstrate that a high degree of succinylation or acetylation can be used to separate the proteins from the PA and to prepare low phytate protein isolates of good functional properties. The separation of PA from the protein in rapeseed flour occurred during the extraction stage, while that in navy bean flour occurred at the isoelectric precipitation stage.     

In situ fibrillar reinforced PET/PA‐6/PA‐66 blend

Ternary fibrillar reinforced blends are obtained by melt‐blending of poly(ethylene terephthalate) (PET), polyamide 6 (PA‐6) and polyamide 66 (PA‐66) (20/60/20 by weight) in the presence of a catalyst, followed by cold drawing of the extruded bristles to a draw ratio of about 3.4 and additional annealing of the drawn blend at 220 or 240°C for 4 or 8 h. The blend samples are studied by DSC, X‐ray diffraction, SEM, and static and dynamic mechanical testing (DMA). SEM and DMA show that PA‐6 and PA‐66 form a homogeneous, continuous matrix in which PET regions are dispersed. X‐ray and DSC measurements of the drawn and annealed at 220°C samples suggest mixed crystallization (solid solubility) of PA‐6 and PA‐66, and cooperative crystallization of PET with the two polyamides. After annealing at 240°C (above the melting point of PA‐6 and below that of PET), the polyamide matrix becomes partially disoriented, while the oriented, fibrillar PET is preserved and plays the role of a reinforcing element. The DSC results for the same samples suggest in situ generation of an additional amount of copolymer. This additional copolymerization, together with that generated during blend mixing in the extruder, improves the compatibility of the blend components (mostly at the PET‐polyamide interface) and alters the chemical composition of the blend.     

天然氨基酸作用下ε-己内酰胺/ε-己内酯的共聚反应

文章研究了天然氨基酸作用下ε-己内酰胺的开环聚合及其与ε-己内酯的共聚反应。结果显示:中性、酸性、碱性等三类氨基酸中,中性两官能团氨基酸作用下ε-己内酰胺的开环聚合反应可以进行。当ε-己内酰胺与L-苯丙氨酸摩尔比等于100,体系在220℃反应48h后,得到粘均分子量为15700g/mol的聚(ε-己内酰胺)。天然氨基酸作用下ε-己内酯和ε-己内酰胺的共聚也可以发生,聚(ε-己内酰胺-co-ε-己内酯)的结构通过GPC,1H-NMR和FT-IR得到证实。     

Influence of the fold surface of the lamellae on radiation effects—research on irradiated polyamide-1010 containing heterogeneous nuclei

Irradiated polyamide-1010 (PA 1010) and PA 1010 containing 0.5% (wt) heterogeneous nuclei were studied by ESR, WAXD, DSC and the determination of gel fractions. The fold surface of the lamellae plays an important role in the effects of radiation on crystalline PA1010. The results show that the direct radiation effects on both samples vary, while after being heated to 220°C, the final radiation effects are identical, regardless of the difference in the amount of the fold surface of the lamellae. The post-radiation effects result predominantly from the fold surface.     

Thermal and electrical properties of aluminum nitride/boron nitride filled polyamide 6 hybrid polymer composites

The effects of boron nitride (BN) and aluminum nitride fillers on polyamide 6 (PA6) hybrid polymer composites were investigated. In particular, the thermal and electrical conductivity, thermal transition, thermal degradation, mechanical and morphological properties and chemical bonds characteristic of the materials with crystal structure of BN and aluminum nitride (AlN) filled PA6 prepared at different concentrations were characterized. Thermal conductivity of hybrid systems revealed a 1.6-fold gain compared to neat PA6. The highest thermal conductivity value was obtained for the composite containing 50 vol% additives (1.040 W/m K). A slight improvement in electrical conductive properties of composites appears and the highest value was obtained for the 50 vol% filled composite with only an increase by 3%. The microstructure of these composites revealed a homogeneous dispersion of AlN and BN additives in PA6 matrix. For all composites, one visible melting peak around 220°C related to the α-form crystals of PA6 was detected in correlation with the X-ray diffraction results. An improved thermal stability was obtained for 10 vol% AlN/BN filled PA6 composite (from 405.41°C to 409.68°C). The tensile strength results of all composites were found to be approximately 22% lower than pure PA6.     

220dtex/18f PA66 FDY生产工艺简介

探讨了切片干燥、纺丝、冷却等工艺条件对生产220 dtex/18f PA66 FDY的影响。结果表明:干燥后切片含水率为300-500 μg/g,纺丝温度282℃,上油率为1.0%,侧吹风有效吹风高度1 800 mm,卷绕速度3 500 m/min,生产稳定,纤维质量优良。     

熔融条件对尼龙612TPU共混物中尼龙结晶行为的影响

用DSC研究了熔融温度与熔融时间对尼龙612(PA612)/聚酯型热塑性聚氨酯弹性体(TPU)共混体系中PA612结晶行为的影响。不同的熔融温度和熔融时间对PA612/TPU的结晶行为影响表明,在相同的熔融温度条件下,PA612的结晶峰温度随着熔融时间的延长向低温方向移动,结晶峰温度和结晶焓值逐渐降低,结晶峰逐渐变宽;在相同的熔融时间条件下,PA612的结晶峰温度随着熔融温度的提高向低温方向移动,结晶峰温度按200℃220℃240℃降低。     

Polyacrylonitrile/Nylon 6 Blends: Preparation and Characterization

Summary: Polyacrylonitrile (PAN) particles with micro‐size ranges (0.15–2 μm) were prepared by emulsion and dispersion polymerizationa and in supercritical carbon dioxide media. The PAN particles were blended with Nylon 6 (PA6) at 220 °C by using a miniature mixer; it was found that melt‐mixing was possible for PAN‐rich compositions as high as 70 wt.‐%. Blends were characterized by scanning electron microscopy, IR, viscosity measurements, differential scanning calorimetry, and dynamic mechanical thermal analysis (DMTA). The size and shape of original PAN particles were retained in PAN/PA6 blends. The useful range to blend PAN particles size was less than 1 μm in terms of shape retention of the PAN particles in blends. Blends with 40 wt.‐% PAN content were found to be melt‐processable. The elastic modulus was higher for PAN/PA6 blends than pure PA6.

SEM photograph of PAN‐SC/PA6 blend with a 40/60 weight ratio.     

Solid‐state polymerization and characterization of a copolyamide based on adipic acid, 1,4‐butanediamine,and 2,5‐furandicarboxylic acid

2,5‐Furandicarboxylic acid (FDCA) is a promising biobased alternative material to terephthalic acid. In this study, three types of poly(butylene adipamide) (PA‐4,6) containing 10, 20, and 30 mol % of poly(butylene‐2,5‐furandicarboxylamide) (PA‐4,F) were synthesized through consecutive prepolymerization and solid‐state polymerization (SSP). The incorporation of a 10 mol % PA‐4,F component into PA‐4,6 resulted in slight increases in the intrinsic viscosity (IV) and glass‐transition temperature (T_g) after 12 h of SSP at 220 °C. When the SSP temperature and reaction time increased, IV increased proportionally. The highest IV value of 0.75 was obtained by 48 h of SSP at 240 °C, whereas increases in the PA‐4,F content to 20 and 30 mol % gave rise to decreases in IV, T_g, and melting temperature; this interrupted the increase in SSP temperature. The thermal decomposition temperature of the PA‐4,F‐incorporated polyamide was lower than that with PA‐4,6 because of the lower thermal stability of the FDCA component. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43391.