In vivo platelet and T-lymphocyte activities during pulmonary tuberculosis

Platelets have been suggested to play a role in the inflammatory response, including defence against bacteria. The aims of this study were to determine in vivo platelet activity during the clinical course of pulmonary tuberculosis and to investigate whether or not there is a correlation between the magnitude of platelet activation and the extent of the pulmonary disease. T-lymphocyte activity was also analysed in the patients. Platelet factor-4 (PF4) and soluble interleukin-2 receptor-alpha (sIL-2Ralpha) concentrations were used as markers of platelet and T-lymphocyte activation, respectively. Twenty-five patients with pulmonary tuberculosis were studied. Fifteen healthy subjects served as a control group. The levels of both sIL-2Ralpha (3,000+/-1,948 pg x mL(-1)) and PF4 (103.1+/-6.7 IU x mL(-1)) were significantly higher in the patients with tuberculosis than in the control group (984+/-360 pg x mL(-1) and 78.2+/-23.9 IU x mL(-1), respectively) (Mann-Whitney U-test, p<0.001 for both comparisons). The plasma PF4 levels were found to be well correlated with the extent of pulmonary lesions on chest radiography (the Spearman's bivariate correlation analysis, r=0.65, p<0.001). However, sIL-2Ralpha concentrations did not correlate with the extent of disease. In conclusion, it has been suggested that platelet and T-lymphocyte activation occurs during pulmonary tuberculosis. The good correlation between platelet activation and the extent of pulmonary tuberculosis might be ascribed to a pathophysiological role of platelets in pulmonary tuberculosis.     

Cloning and nucleotide sequences of the topoisomerase IV parC and parE genes of Mycoplasma hominis

The topoisomerase IV parC and parE genes from the wall-less organism Mycoplasma hominis PG21 were cloned and sequenced. The coupled genes are located far from the DNA gyrase genes gyrA and gyrB. They encode proteins of 639 and 866 amino acids, respectively. As expected, the encoded ParE and ParC proteins exhibit higher homologies with the topoisomerase IV subunits of the gram-positive bacteria Staphylococcus aureus and Streptococcus pneumoniae than with their Escherichia coli counterparts. The conserved regions include the Tyr residue of the active site and the region involved in quinolone resistance (quinolone resistance-determining region [QRDR]) in ParC and the ATP-binding site and the QRDR in ParE.     

电子束在硅中的能量损耗

利用矩法对能量从0.5～8 MeV的电子束在硅中的能量损耗分布作了理论计算。并对相应的轫致辐射能损分布作了近似计算。得到了硅中吸收剂量对深度的分布。     

Scientific information of health personnel: an approach to the sources, access, costs and research

OBJECTIVE: To study the appropriateness of minimally invasive surgical treatment of primary hyperparathyroidism. DESIGN: Prospective. SETTING: University Hospital Utrecht, the Netherlands. METHOD: In patients with primary hyperparathyroidism, parathyroid adenomas were located preoperatively by means of Doppler assisted ultrasonography and spiral computer tomography. If the results were positive, minimally invasive surgery was performed. RESULTS: Minimally invasive surgery was carried out in 13 out of 15 successive patients with good results (the serum calcium and parathyroid hormone levels returned to normal). Two patients were subjected to conventional neck exploration, also with good results (preoperatively several adenomas were suspected in one, while no adenoma was seen in the other). CONCLUSION: It can be calculated that minimally invasive surgery will probably suffice in 60-70% of the patients with primary hyperparathyroidism, so that conventional neck exploration can be avoided.     

摩擦挤压焊接铝-钢接头的组织与性能研究

文章研究了LF5铝与A3钢摩擦挤压焊接工艺,该工艺已成功用于工业生产铝/钢电解电极。通过分析焊接工艺参数对LF5铝与A3钢接头金相组织、力学性能及导电性能的影响,获得了最佳的工艺参数。试验结果表明:摩擦挤压焊接形成的铝-钢接头的摩擦端面连接及螺纹挤压咬合连接提高了接头强度。通过该技术获得的焊接接头的导电性及力学性均能满足实际工业生产的要求。最优的摩擦挤压焊接参数是:旋转速度1 000 r/min,摩擦压力2.5 MPa,摩擦时间7 s,顶锻压力3.5 MPa,顶锻时间4 s。     

从苯酐废料中提取马来酸并制备高纯度富马酸

以苯酐废料为原料,采用升华的方法,从中提取出马来酸,并且将其制备成高纯度的白色透明针状晶体富马酸;同时,研究了反应温度和时间对高纯度富马酸产率的影响。实验结果表明,在设定的温度与时间内,富马酸的产率随着反应温度的升高或加热时间的延长而增大,且当反应温度为220 ℃,反应时间为20 min时,富马酸的产率最高,达88.8%。此外,采用液相色谱仪对产品的纯度进行了测定,结果表明采用升华法得到的产品的纯度高达99.99%;且产品的红外光谱图中,在925 cm-1位置处出现了反式烯烃的特征吸收峰,证实了产物为富马酸。最佳实验条件的验证结果表明,采用升华法从工业废料中生产富马酸,不仅产率较高,且实验重现性较好。     

Polycaprolactone‐hydroxy apatite composites for tissue engineering applications

In this study, scaffolds with polycaprolactone (PCL) and hydroxy apatite (HA) were produced. Their properties are not sufficient to be used alone. Oleic Acid (OA) and glycerol monooleate (GMO) as organic additives were selected for a homogeneous distribution of the ceramic material in the polymer matrix. Biocomposite materials were prepared with solvent casting‐salt leaching technique using dichloromethane as the solvent. Salt was used as the porosifier. Materials were kept in simulated body fluid (SBF) to determine the bioactivity in vitro conditions. FTIR and EDX analyses for chemical characterization, tensile and compressive tests for mechanical properties, SEM analyses for surface properties and BET analyses for pore sizes, total surface areas and total pore volumes of scaffolds were performed. FTIR, EDX, and SEM analyses were repeated after SBF treatment. Pore diameters were highly increased with 3 and 20 wt% HA addition. Small amount of GMO addition is more effective on pore size. Mechanical properties of scaffolds were suitable for soft tissue applications, as smooth muscle cells, skin and cancellous bone. The cytotoxicity and cell proliferation on scaffolds were studied with smooth muscle cells (SMC) and L929 fibroblastic cells in vitro. No cytotoxic effect was observed for the scaffolds in both cell types. J. VINYL ADDIT. TECHNOL., 24:248–261, 2018. © 2016 Society of Plastics Engineers     

Hybrid SNR-Adaptive Multiuser Detectors for SDMA-OFDM Systems

Multiuser detection (MUD) and channel estimation techniques in space-division multiple-access aided orthogonal frequency-division multiplexing systems recently has received intensive interest in receiver design technologies. The maximum likelihood (ML) MUD that provides optimal performance has the cost of a dramatically increased computational complexity. The minimum mean-squared error (MMSE) MUD exhibits poor performance, although it achieves lower computational complexity. With almost the same complexity, an MMSE with successive interference cancellation (SIC) scheme achieves a better bit error rate performance than a linear MMSE multiuser detector. In this paper, hybrid ML-MMSE with SIC adaptive multiuser detection based on the joint channel estimation method is suggested for signal detection. The simulation results show that the proposed method achieves good performance close to the optimal ML performance at low SNR values and a low computational complexity at high SNR values.     

Impact of Nonfullerene Molecular Architecture on Charge Generation,Transport, and Morphology in PTB7‐Th‐Based Organic Solar Cells

Despite the rapid development of nonfullerene acceptors (NFAs), the fundamental understanding on the relationship between NFA molecular architecture, morphology, and device performance is still lacking. Herein, poly[[4,8‐bis[5‐(2‐ethylhexyl)thiophene‐2‐yl]benzo[1,2‐b:4,5‐b0]dithiophene‐2,6‐diyl][3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]‐thieno[3,4‐b]thiophenediyl]] (PTB7‐Th) is used as the donor polymer to compare an NFA with a 3D architecture (SF‐PDI4) to a well‐studied NFA with a linear acceptor–donor–acceptor (A–D–A) architecture (ITIC). The data suggest that the NFA ITIC with a linear molecular structure shows a better device performance due to an increase in short‐circuit current ( J_sc) and fill factor (FF) compared to the 3D SF‐PDI4. The charge generation dynamics measured by femtosecond transient absorption spectroscopy (TAS) reveals that the exciton dissociation process in the PTB7‐Th:ITIC films is highly efficient. In addition, the PTB7‐Th:ITIC blend shows a higher electron mobility and lower energetic disorder compared to the PTB7‐Th:SF‐PDI4 blend, leading to higher values of J_sc and FF. The compositional sensitive resonant soft X‐ray scattering (R‐SoXS) results indicate that ITIC molecules form more pure domains with reduced domain spacing, resulting in more efficient charge transport compared with the SF‐PDI4 blend. It is proposed that both the molecular structure and the corresponding morphology of ITIC play a vital role for the good solar cell device performance.