Influence of protamine on the in vitro sensitivity of Pseudomonas aeruginosa to antibiotics

We have studied the influence of protamine on the sensitivity of three strains of Pseudomonas aeruginosa to various antibiotics: streptomycin, gentamicin, polymyxin B, and β-lactams. While protamine enhanced the antibacterial action of β-lactams towards P. aeruginosa, it did not alter the effect of aminoglycosides. The antibacterial power of polymyxin B, on the other hand, was drastically reduced. The observed changes in this strain's sensitivity to antibiotics could be due to changes in the permeability of the outer membrane.     

Lumbar epidural fentanyl infusions for post-thoracotomy patients: Analgesic,respiratory, and pharmacokinetic effects

Ten patients undergoing a thoracotomy were studied for 24 hours postoperatively to determine the effects of a continuous lumbar epidural fentanyl infusion on postoperative pain, arterial blood gases (ABG), respiratory pattern (respiratory inductive plethysmography, RIP), and fentanyl plasma concentration (CONC). Patients served as their own controls because RIP and ABG data were obtained the night prior to surgery during sleep. Epidural fentanyl was administered as a bolus of 1.5 μg/kg followed by an infusion of 1.0 μg/kg/h started 1 hour after induction. Insufficient analgesia was treated with a bolus of 0.5 μg/kg and an infusion increase of 0.25 μg/kg/h. Postoperative assessment included RIP, ABG, CONC, and visual analog pain score (PS). The average infusion rate postoperatively was 1.47 ± 0.08 μg/kg/h (114.3 ± 8.3 μg/h). A mean PS of 2.1 ± 0.3 was achieved; however, there was a delay in attaining this. There was no significant incidence postoperatively of apnea or slow respiratory rate. A significant byt clinically insubstantial increase in PaCO₂ and decrease in pH occurred. A steady state CONC of approximately 2.0 ng/mL was reached after 9 hours. The PS correlated with CONC in half the patients (0.60 < r < 0.86), indicating a systemic component may have contributed to the analgesic effect.     

氮网球花定碱盐酸盐对活化T细胞增殖的抑制作用

目的 探究氮网球花定碱盐酸盐(NMHC)抑制活化T细胞增殖的作用机制.方法 Ficoll法提取分离健康人外周血单个核细胞(PBMC),免疫磁珠法纯化出PBMC中的T细胞,抗人CD3/CD28抗体活化纯化后的静息T细胞.NMHC 0.125,0.5,2和8μmol·L-1与静息T细胞作用,用流式细胞术检测细胞毒性(96 ...     

Preparation and characterization of a self-suspending ultra-low density proppant

A self-suspending ultra-low density proppant (UDP) was developed based on the polymerization of the unsaturated carbon double bond. Its performance was characterized by FT-IR and SEM, and the sphericity and roundness, diameter distribution, density, mechanical properties, the conductivity of the propped fracture, and mass loss of different fluids were measured. The test results indicated that the UDP no longer contained the unsaturated carbon double bond and the polymerization took place in the raw material. The fracture surface of UDP is compact and it is not easy to produce debris after compression failure. The sphericity and roundness of UDP were above 0.9, and the high sphericity and roundness provided high conductivity. The stirring speed has a great influence on the diameter of UDP, and the UDP with different sizes could be used to prop the hydraulic fracture to different widths. The average apparent density of UDP is as low as 1.044 g cm⁻³, and it can be suspended in the fracturing fluid for a long time. The strain in the UDP is higher than that in the ceramsite and quartz sand, but its crushing ratio is far below theirs; therefore, the conductivity of the fracture propped by UDP was higher than that of quartz sand and ceramsite. The solubility of UDP in kerosene, reservoir water, and hydrochloric acid is below 1%, indicating that the UDP is also suitable for acid fracturing with proppant. All the experimental results proved that the self-suspending ultra-low density proppant has great potential use in hydraulic fracturing and acid fracturing.

A self-suspending ultra-low density proppant (UDP) was developed based on the polymerization of the unsaturated carbon double bond.     

Anatomies for the thermal decomposition behavior and product rule of 5,5′-dinitro-2H,2H′-3,3′-bi-1,2,4-triazole

High-performance energetic materials are mainly used in the military, aerospace industry and chemical fields. The ordinary technology of producing energetic materials cannot avoid the domination of its unique needs. At present, revealing the underlying mechanism of the formation of high-energy materials is of great significance for improving their quality characteristics. We pay special attention to the decomposition and reactive molecular dynamics (RMD) simulation of 5,5′-dinitro-2H,2H′-3,3′-bi-1,2,4-triazole (DNBT). Various forms were captured in the simulation, and the form is determined by the temperature of the initial reactant. By observing the heating pattern and morphological changes under the initial thermal equilibrium, interesting temperature jumps were found in 325 K and 350 K. Observation of continuous heating (simulated temperatures are 2600 K, 2900 K, 3200 K and 3500 K) shows that DNBT has the maximum heating rate at 3500 K. In addition, N₂ occupies this dominant position in the product, moreover, N₂ and NO₂ respectively dominate the gas phase products during the initial heating process. According to the transition state analysis results of the intermediates, we found 4 interesting intermediate products, which were determined by high frequency reaction under the 4 simulated temperatures and performed with transition state calculations. It shows that the selection of reactant temperature and its activity is the key to orderly decomposition of DNBT. It is expected that these findings will be widely used in comprehensive decomposition devices and to improve the concept of learning military and industrial technology.

The performance and behavior of DNBT under RMD simulation at high temperature (2600 K, 2900 K, 3200 K and 3500 K).

Energetic materials (EMs), such as TNT, RDX, TATB, nitroguanidine and nitro imidazoles, have risen in the scientific community because of their unique properties.^1–4 Findings and discoveries of nitro metal salts and high energy density materials (HEDMs) in the early stage has obviously indicated the beginning of the epoch of EMs. The detonation velocity and pressure depend on the material density, with a high energy density trending to increase the explosive capability. Notably, this dinitrotriazoles are the only ones among these energetic materials whose large-scale industrial production has been an accustomed pursuit.⁵ Research on triazoles with high thermo stabilities reported by Seth and Matzger in 2016 further highlights the high expectations and applications for triazole materials.⁶ Dinitrotriazoles have been observed and researched as coordination polymerization, water–salts degradation,⁷ lighting sensor for fluorescent materials⁸ and energetic nano microcapsules⁹ successfully, in contrast with the traditional mechanical,¹⁰ electronic¹¹ and optical properties,¹² moreover, dinitrotriazoles are applied in various fields of material science and technology such as fuel cells¹³ and catalysts,¹⁴etc.5,5′-Dinitro-2H,2H′-3,3′-bi-1,2,4-triazole (DNBT) is a potential explosive that can be synthesized in two steps starting from aminoguanidinium carbonate and oxalic acid. The synthesis strategies of DNBT include conventional ways are evaluable, related report mentioned by the crystallization screening experiment that the water solubility is relatively stable for DNBT under the environment of methyl cyanide (MeCN) with a proportion 1 : 2 and 1 : 1.515.¹⁵ DNBT prepared via these techniques is always have a diversity sample such as form of crystal, water activity slurry, crystallization of the initial solvates, non-solvates titration (crystal powder used for catalyst), whatsmore, removing these diversity sample is improved to be a changeable task which can turn on the limitation and potential application of DNBT. Despite that, the investigation of thermal decomposition phenomenon¹⁶ is still one of the urgent problems to be solved in the current research for EMs, meanwhile, could be a good solution and approaches for DNBT to reveal the insight of the structure from crystal between the inner-molecule and inter-molecules. Nevertheless, the molecule structure analysis and the response character during the decomposition for reaction of DNBT get fail to obtain more effective results from the reactants and products, more than this, existing experimental methods cannot meet the current needs as dealing with these micro-mechanism issues. Unfortunately, these similar issues begin to need a sufficient discussion and the tow mechanism of hot smoking vapored formation which dominated by the polyyne model¹⁷ and energetic ion salt research,^18–20 are still debating. To learn and comprehensive mechanisms of rules for decomposition reaction under the consideration of choosing starting temperature and setting reactive condition, shall be helpful and advantageous to produce of DNBT controllably and efficiently.In recent years, many kinetic models and dynamic simulations have been developed to describe the chemical process of thermal degradation for nitro-compound and nitro ion salts, though there will be temperature and pressure enhancement in these simulations, it has been proven extensively that the enhancement will not give rise to any artificial feature.^21–25 It''s a common approach of various molecular dynamics (MD) simulation to increase temperature significantly to overcome the limit for time scale. However, these processes are adopted to both comparing and fitting the elementary reactions with experimental observations to determine dominant reaction in the total conversions, and also cannot provide dynamic details of chemical conversion. Reactive force field with lg potential terms (ReaxFF-lg) become one of the opportunities to solve these problems by simulating chemical reactions via reactive molecular dynamics simulation (RMD), which can parsing more details of complicated chemical procedure under a given specific condition as time and space scale, the energy terms component described as eqn (1)–(3), where E_reax is the energy evaluated from the previous ReaxFF,²⁶E_lg is the long-range correction using the low-gradients method.²⁷E_Reax-lg = E_Reax + E_lg1E_Reax = E_bond + E_lp + E_over + E_under + E_val + E_pen + E_coa + E_tors + E_conj + E_H-bond + E_vdW + E_Coulomb23The unknown decomposition and degradation mechanism of different nitro-compound push us to extend the previous studies to more intentional reactive behavior for DNBT during analyses performed by combine the results in the micro scale^28–31 that gave us a remarkable understanding of the thermal decomposition behavior of DNBT. Moreover, as a classic secondary explosive^32–35 and from the perspective of safety, this makes us need to pay more attention to the performance of heating trend. More interesting information has been found. The initial degradation and decomposition accompany with temperature for DNBT undergoes the following stage, (i) selection of the initial thermal equilibrium temperature, (ii) dynamic changes for the potential and temperature of the system during heating process in the high temperature range, (iii) evaluating the generation of product and statistic the high frequency reaction during the decomposition process. Besides that, the transition state calculation and analysis of the electronic structure for the intermediate product in high-frequency decomposition reactions are also been investigated and discussed.     

CPT1A在能量应激时卵巢癌细胞生存中的调控作用

目的 研究人肉毒碱棕榈酰基转移酶1A(carnitine palmitoyltransferase 1A,CPT1A)在能量应激时(饥饿处理)卵巢癌细胞生存中的调控作用.方法 ①用qRT-PCR与Western Blot实验,检测能量应激对卵巢癌细胞中CPT1A表达的影响.②siRNA下调CPT1A后,用流式分析其对能...     

Forebrain commissures and visual memory: A new approach

The primary purpose of these exploratory experiments was to determine: (1) whether the forebrain commissures can provide full accessibility of the mnemonic store to either hemisphere when the task involves memory for ‘events’ (images) rather than, as in essentially all previous tests on split-brain animals, memory for ‘rules’ (discrimination habits); and (2) whether the anterior commissure (AC) alone is capable of such function. Macaques, with optic chiasm transected to allow limitation of direct visual input to one or the other hemisphere, were trained on tasks requiring recognition of previously viewed photographic slides. For one task, delayed-matching-to-sample (DMTS), the animal was presented with a ‘sample’ image, and then 0–15 s later was required to choose that image in preference to a second image concurrently displayed. On the other task, running recognition (RR), a series of images was presented, some of which were repetitions of images previously seen in that session, and the animal was required to signal its recognition of these repetitions. For either task the initial presentation could be made to one eye and hemisphere, and subsequent recognition required of the other.In such circumstance, if all forebrain commissures were divided, such interhemispheric recognition was no longer possible. For the DMTS task if either the AC or 5 mm of the splenium of the corpus callosum were available, interhemispheric recognition was basically equivalent to that using the same eye and hemisphere. However, interhemispheric accuracy with the RR task, while well above chance levels, was consistently inferior to that achieved intrahemispherically when complex scenes or objects were viewed. This is probably a consequence mostly of the differing visual fields of the two eyes, since interhemispheric accuracy was greatly improved by use of images having approximately identical right and left halves. No consistent hemispheric specialization nor difference in direction of interhemispheric communication was observed despite the use of different types of material and the different mnemonic tasks. It is concluded that the AC in macaques can achieve full and continuously operative neural unification of the mnemonic traces of past experience.     

《中国药典》中药材基原和药用部位的变化规律研究

在中药品种、品质与资源等理论的指导下,以中药临床疗效一致和有药可用为据,从历版《中国药典》中药材的基原和药用部位的视角,分析其变化原因和探索其变化规律。预测药典收载植物类中药材数量、多基原品种数量和多部位品种数量的变化趋势,并对其存在的不足之处提出建议,以实现中药材质量的有效控制。     

血府逐瘀汤配合针灸治疗对缺血性脑卒中偏瘫患者颅内血流动力学、肢体运动功能和生命质量的影响

目的:探讨血府逐瘀汤配合针灸对缺血性脑卒中(CIS)偏瘫患者颅内血流动力学、肢体运动功能和生命质量的影响。方法:选取2015年1月至2018年1月成都医学院第一附属医院神经内科收治的CIS偏瘫患者150例作为研究对象。按照随机数表法随机分为观察组和对照组,每组75例,观察组采用血府逐瘀汤+针灸治疗,对照组采用常规治疗。于治疗前及治疗1个月后检测2组患者大脑前动脉(ACA)、中动脉(MCA)及后动脉(PCA)平均血流速度(Vm),评估肢体运动功能如Fugl-Meyer运动功能评定量表(FMA)和生命质量[脑卒中生命质量量表(SS-QOL)],检测促红细胞生成素(EPO)、基质金属蛋白酶-9(MMP-9)、同型半胱氨酸(Hcy)水平,比较2组患者中医症状积分(舌质暗红、口唇及齿龈暗、爪甲紫暗、面色晦暗、偏身麻木、手足肿胀)差异。结果:治疗1个月后时,2组ACA、MCA、PCA的V_m及血清EPO、MMP-9、Hcy水平、中医症状积分均较治疗前时降低,且观察组低于对照组,差异有统计学意义(P 0. 05); FMA、SS-QOL评分均较治疗前时升高,且观察组高于对照组,差异有统计学意义(P 0. 05)。结论:血府逐瘀汤配合针灸可显著改善CIS偏瘫患者颅内血流动力学状态、肢体运动功能、生命质量及中医症状,减轻脑组织损伤,于促进患者疾病恢复有利。     

Impact of obesity on the efficacy of different biologic agents in inflammatory diseases: A systematic review and meta-analysis

Objective

Obesity is a worldwide epidemic and a growing body of evidence suggests that it may affect the body's response to biologic agents. We investigated the influence of obesity on the efficacy of different biologic agents used to treat inflammatory diseases.