Effects of Fiber Angle on the Tensile Properties of Partially Delignified and Densified Wood

Partial delignification and densification provide a pathway to significant improvement in the mechanical performance of wood. In order to elucidate potential effects of this treatment on the mechanical anisotropy of wood, partially delignified and densified spruce wood veneers were characterized at varying degrees of off-axis alignment. While the tensile strength and the modulus of elasticity (MOE) were clearly improved in parallel to the axis of wood fibers, this improvement quickly leveled off at misalignment angles ≥30°. For transverse tensile strength, the performance of alkaline-treated and densified wood was even inferior to that of untreated wood. Microscopic examination revealed the presence of microscopic cracks in treated wood, which are assumed to be responsible for this observation. It is concluded that impaired transverse tensile properties are a weakness of partially delignified and densified wood and should be considered when a potential usage in load-bearing applications is intended.     

Prognostic value of neutrophil-to-lymphocyte ratio in patients treated with concurrent chemoradiotherapy for locally advanced oesophageal cancer

BackgroundWe performed a retrospective analysis of Asian patients with locally advanced oesophageal cancer to test the hypothesis that an elevated neutrophil-to-lymphocyte ratio is associated with a poor survival rate after definitive concurrent chemoradiotherapy.MethodsIn total, 138 patients diagnosed with locally advanced oesophageal cancer (TNM classification of malignant tumours stage II or III) who were treated with definitive concurrent chemoradiotherapy between January 2005 and December 2010 were retrospectively analysed. Definitive concurrent chemoradiotherapy was performed using two different chemotherapy regimens.ResultsThe median follow-up duration was 39.5 months (range 1.1–93.4). The median progression-free survival was 14.0 months, and the median overall survival was 19.9 months. Compared with the low (<2.0) neutrophil-to-lymphocyte ratio group (n = 43, 31.2%), the high (≥2.0) neutrophil-to-lymphocyte ratio group (n = 95, 68.8%) exhibited significant decreases in the durations of both progression-free survival and overall survival. Using multivariate analysis, an elevated neutrophil-to-lymphocyte ratio was also significantly associated with decreased progression-free survival (HR 1.799; 95% CI, 1.050–3.083; P = 0.032) and overall survival duration (HR 2.115; 95% CI, 1.193–3.749; P = 0.010).ConclusionsThe pretreatment neutrophil-to-lymphocyte ratio is a useful prognostic marker in patients with locally advanced oesophageal cancer treated with definitive concurrent chemoradiotherapy.     

Cerebrovascular changes in the rat brain in two models of ischemia

BackgroundVascular occlusion and cyanide neurotoxicity induces oxidative stress and degeneration in the brain. This oxidant induced stress changes the vascular dynamics of cerebral blood vessels, and participates in homeostatic response mechanisms which balance oxygen supply to hypoxic stress-sensitive neurons. The associated changes in vascular morphology include remodeling of the microvasculature and endothelial changes, alterations in regional circulation and variations in the blood brain barrier (BBB). This study compares alterations in physiology of the cerebral artery after a short-term oxidative stress induced by cyanide toxicity and vascular occlusion.MethodAdult Wistar rats (N = 30) were divided into three groups; vascular occlusion (VO) (n = 12), potassium cyanide administration (CN) (n = 12) and Control-CO (n = 6). The CN rates were treated with 30 mg/kg of orally administered KCN while the VO was subjected to global vascular occlusion, both for a duration of 10 days, described as the treatment phase. Control animals were fed on normal rat chow and water for 10 days. At the end of the treatment phase, n = 6 animals in each of the VO, CN and VO groups were anesthetized with sodium pentobarbital (50IP) and the CCA exposed, after which pin electrodes were implanted to record the spikes form the tunica media of the CCA. After day 10, treatment was discontinued for these animals, each remaining in the VO and CN groups (VO-I and CN-I) until day 20 (withdrawal phase) following which the spikes were recorded using the procedure described above.Results/DiscussionVascular occlusion and cyanide toxicity increased vascular resistance in the MCA (reduced lumen thickness ratio) and increased the diameter of the CCA after the treatment phase of 10 days. After 10 days of withdrawal, the VO group showed a reduction in resistance and an increase in the lumen width/wall thickness ratio (LWR) while the CN group showed increased resistance and a reduction in LWR.ConclusionCyanide toxicity increased vascular resistance by inducing degenerative changes in the wall of the artery while vascular occlusion increased resistance through mechanical stress and increased thickness of arterial wall. After the withdrawal phase, vascular resistance diminished in the VO to a significantly greater extent than the CN.     

Synthesis and Characterization of Polymerized Ionic Liquids: Mechanical and Thermal Properties of a Novel Type of Hydrogels

An easy and efficient route to synthesize gel materials based on polymeric ionic liquids (PILs) is presented. The radical polymerization of imidazolium (Im)‐based ionic liquids (ILs) bearing a vinyl group ([VEIm][Br], [VEIm][Ac], [VBIm][Br], [VBIm][Cl]) with crosslinker (CL) N,N′‐methylenebisacrylamide (Bis) in water results in polyionic liquid hydrogels. Thermal and mechanical properties (tensile and compression tests) are investigated and compared with two different types of hydrogels. One is a polyacrylamide (PAAm) hydrogel having covalent‐type crosslinking. The other is an alginate‐based hydrogel having ionic‐type crosslinking. Prepared IL‐hydrogel materials provide favorable flexibility, adjustable by varying the CL ratio and water content. The higher the CL ratio is, the higher the fragility of the gel matrix. The gelation time of the hydrogels depends on the alkyl chain length, as well as the size of the anion.

     

Bennett acceptance ratio method to calculate the binding free energy of BACE1 inhibitors: Theoretical model and design of new ligands of the enzyme

In recent years, the design, development, and evaluation of several inhibitors of the BACE1 enzyme, as part of Alzheimer's treatment, have gathered the scientific community's interest. Here, a linear regression model was built using binding free energy calculations through the Bennett acceptance ratio method for 20 known inhibitors of the BACE1 enzyme, with a Pearson coefficient of R = 0.88 and R² = 0.78. The validation of this model was verified employing eight additional random inhibitors, which also gave a linear correlation with R = 0.97 and R² = 0.93. Furthermore, this linear regression model was also used for proposing the structure of four potential BACE1 inhibitors, and the most active of them gave a theoretical K_d = 10 nM. However, these molecules have not been synthesized yet. Our team used a total time of more than 800 ns for the Molecular Dynamics to carry out this study, and all the software used were freely available.     

Ionized magnesium and calcium concentration and their ratio in equine plasma samples as determined by a regulatory laboratory compared to a clinical reference laboratory

Magnesium sulfate (MgSO₄) was administered to calm competition horses. We evaluated the impact of regulatory requirements for the handling of blood samples on plasma ionized magnesium (iMg), ionized calcium (iCa), the iMg to iCa ratio, and pH. We hypothesized that iCa, iMg. and iMg/iCa would be similar among storage and collection methods. Four blood samples were collected from each of 50 horses on the same day: Group 1 – collection in a heparinized syringe and processed within hours in a clinical laboratory; Group 2 – collection into a plasma separator tube (PST) centrifuged just prior to analysis, and plasma processed as in (1); Group 3 – collection into a PST, refrigerated, shipped via overnight carrier to the United States Equestrian Federation (USEF) Equine Drug Testing and Research laboratory, centrifuged just prior to analysis, and plasma processed; and Group 4 – as in Group 3, but stored frozen at ?80°C for 90 days, thawed, and plasma processed as in Group 3. Results for iMg/iCa are unit‐less, adjusted iMg for potential influence of plasma protein and iCa, and highly correlated with iMg pH (r = ?.933; P < 0.01). Samples processed immediately in a clinical reference laboratory had the greatest iMg/iCa. Both iMg/iCa and pH predictably decreased after freezing (P < 0.001). These data suggest that the iMg/iCa mirrors alterations in iMg regardless of storage and collection methods. This understanding can facilitate the development of a regulatory threshold for the control of the nefarious use of magnesium sulfate in competing horses, and an understanding of potential changes to iMg/iCa with storage of B samples.     

外周血中性粒细胞/淋巴细胞比值与透析患者冠状动脉钙化的关系

目的 通过透析患者资料分析该人群冠状动脉钙化(CAC)的危险因素,探讨中性粒细胞/淋巴细胞比值(NLR)对CAC的预测价值。方法 采用横断面调查方法,对163例透析患者(包括血液透析102例,腹膜透析61例)进行回顾性研究,根据多层螺旋CT评估结果,采用Agatston冠状动脉钙化积分(CACS)进行冠状动脉钙化程度的评估,将透析患者分成无钙化组59例(CACS 0～10分)和钙化组104例(CACS≥11分)。对两组患者的NLR、年龄、透析龄、高敏C反应蛋白(hs-CRP)、血钙、血磷、全段甲状旁腺激素(iPTH)、白蛋白(Alb)、血红蛋白、血清肌酐等指标进行统计学比较。应用Spearman相关性分析得出与CAC相关的因素,二元Logistic回归分析CAC发生的危险因素,受试者工作特征(ROC)曲线探讨NLR对CAC的预测价值。结果 163例透析患者中CAC总检出率为63.8%。钙化组NLR显著高于无钙化组(P＜0.001)。将钙化组分为轻度钙化组(CACS 11~400分)和重度钙化组(CACS＞400分),两亚组间NLR差异无统计学意义。Spearman相关性分析显示NLR与CAC显著相关(r＝0.403,P＜0.001)。二元Logistic回归分析结果显示年龄(OR=1.069,P＜0.001)、透析龄(OR=1.024,P＜0.001)、糖尿病(OR=15.871,P＝0.012)、NLR(OR=1.720,P＝0.001)是CAC的危险因素。ROC曲线分析结果显示,NLR与年龄的联合指标预测透析患者发生CAC时,曲线下面积为0.810(95%CI 0.739~0.880,P＜0.001),显著高于NLR(0.742,95%CI 0.666~0.818,P＜0.001)和年龄(0.754,95%CI 0.674~0.834,P＜0.001)单独分析时的曲线下面积。结论 高龄、透析龄和高水平NLR的透析患者发生CAC的风险较高,且NLR与年龄的联合指标对CAC的发生有着较好的预测价值。     

Development and validation of a method to confirm the exogenous origin of prednisone and prednisolone by GC‐C‐IRMS

Prednisone and prednisolone are two anti‐inflammatory steroidal drugs listed by the World Anti‐Doping Agency (WADA) within the class of glucocorticoids, which are prohibited “in competition” and when administered systemically. Their presence in collected urine samples may be attributed, if no exogenous administration has occurred, to an in situ microbial formation from endogenous steroids. In this work, a gas chromatography coupled to carbon isotope ratio mass spectrometry (GC‐C‐IRMS) method was developed and validated to distinguish an exogenous origin from an endogenous one. Eight prednisone/prednisolone pharmaceutical preparations commercially available in Italy were analysed to establish an exogenous δ¹³C value reference range (?28.96 ± 0.39‰). No more than 25 mL of urine was processed and no derivatization nor intentional steroids structure modifications were performed before the GC‐C‐IRMS analysis. A first HPLC purification step was set up to isolate the three endogenous reference compounds (ERCs) selected (tetrahydro‐11‐deoxycortisol (THS), pregnanediol (PD), and pregnanetriol (PT)), while a second LC purification was necessary to separate prednisone from prednisolone. In the GC‐C‐IRMS analysis, two different GC run methods were set up to guarantee better sensitivity and selectivity for each compound. Both prednisone and prednisolone showed signals (m/z 44) with amplitudes within the method linearity range to a lower urinary concentration of 20 ng/mL (< WADA reporting level, 30 ng/mL). The method was fully validated according to WADA requirements. As a proof of concept, urine samples collected from two excretion studies in healthy male volunteers, after a prednisone or prednisolone administration, were analysed by the proposed method, demonstrating its applicability for the analysis of real samples.