The exogenously acquired 16S rRNA methyltransferases RmtD, RmtD2, and RmtG were cloned and heterologously expressed in Escherichia coli, and the recombinant proteins were purified to near homogeneity. Each methyltransferase conferred an aminoglycoside resistance profile consistent with m7G1405 modification, and this activity was confirmed by invitro 30S methylation assays. Analyses of protein structure and interaction with S-adenosyl-l-methionine suggest that the molecular mechanisms of substrate recognition and catalysis are conserved across the 16S rRNA (m7G1405) methyltransferase family. 相似文献
This work provides valuable information about unexplored catalytic systems tested in the transesterification reaction of vegetable oil with methanol. It was demonstrated that natural zeolite treatment leads to enhanced catalytic activity and yield of biodiesel production. The activation of the catalytic material in a mixture of 5% H2–95% Ar resulted in an improvement of the values of the TG conversion and fatty acid methyl esters (FAME) yield. In addition, it was proven that the incorporation of CaO, MgO and SrO oxides onto the natural zeolite surface improves the TG conversion and FAME yield values in the transesterification reaction. 相似文献
In the present work, we investigated in detail the thermal/crystallization behavior and magnetic properties of materials with Fe84.5-xCoxNb5B8.5P2 (x = 0, 5, 10, 15 and 20 at.%) composition. The amorphous ribbons were manufactured on a semi-industrial scale by the melt-spinning technique. The subsequent nanocrystallization processes were carried out under different conditions (with/without magnetic field). The comprehensive studies have been carried out using differential scanning calorimetry, X-ray diffractometry, transmission electron microscopy, hysteresis loop analyses, vibrating sample magnetometry and Mössbauer spectroscopy. Moreover, the frequency (up to 300 kHz) dependence of power losses and permeability at a magnetic induction up to 0.9 T was investigated. On the basis of some of the results obtained, we calculated the values of the activation energies and the induced magnetic anisotropies. The X-ray diffraction results confirm the surface crystallization effect previously observed for phosphorous-containing alloys. The in situ microscopic observations of crystallization describe this process in detail in accordance with the calorimetry results. Furthermore, the effect of Co content on the phase composition and the influence of annealing in an external magnetic field on magnetic properties, including the orientation of the magnetic spins, have been studied using various magnetic techniques. Finally, nanocrystalline Fe64.5Co20Nb5B8.5P2 cores were prepared after transverse thermo-magnetic heat treatment and installed in industrially available portable heating equipment. 相似文献
Pasireotide is an effective treatment for acromegaly and Cushing’s disease, although treatment-emergent hyperglycemia can occur. The objective of this study was to assess incretin-based therapy versus insulin for managing pasireotide-associated hyperglycemia uncontrolled by metformin/other permitted oral antidiabetic drugs.
Methods
Multicenter, randomized, open-label, Phase IV study comprising a core phase (≤?16-week pre-randomization period followed by 16-week randomized treatment period) and optional extension (ClinicalTrials.gov ID: NCT02060383). Adults with acromegaly (n?=?190) or Cushing’s disease (n?=?59) received long-acting (starting 40 mg IM/28 days) or subcutaneous pasireotide (starting 600 µg bid), respectively. Patients with increased fasting plasma glucose (≥?126 mg/dL on three consecutive days) during the 16-week pre-randomization period despite metformin/other oral antidiabetic drugs were randomized 1:1 to open-label incretin-based therapy (sitagliptin followed by liraglutide) or insulin for another 16 weeks. The primary objective was to evaluate the difference in mean change in HbA1c from randomization to end of core phase between incretin-based therapy and insulin treatment arms.
Results
Eighty-one (32.5%) patients were randomized to incretin-based therapy (n?=?38 received sitagliptin, n?=?28 subsequently switched to liraglutide; n?=?12 received insulin as rescue therapy) or insulin (n?=?43). Adjusted mean change in HbA1c between treatment arms was – 0.28% (95% CI – 0.63, 0.08) in favor of incretin-based therapy. The most common AE other than hyperglycemia was diarrhea (incretin-based therapy, 28.9%; insulin, 30.2%). Forty-six (18.5%) patients were managed on metformin (n?=?43)/other OAD (n?=?3), 103 (41.4%) patients did not require any oral antidiabetic drugs and 19 patients (7.6%) were receiving insulin at baseline and were not randomized.
Conclusion
Many patients receiving pasireotide do not develop hyperglycemia requiring oral antidiabetic drugs. Metformin is an effective initial treatment, followed by incretin-based therapy if needed.
The shaping process of surface texture is complicated and depends on many factors and phenomena accompanying them. This article presents the author’s test stand for the measurement of relative displacements in a tool–workpiece system during longitudinal turning. The aim of this study was to determine the influence of edge radius on the relative displacement between the tool and workpiece. The cutting process was carried out with inserts with different edge radii for X37CrMoV5-1 steel. As a result of the research, vibration charts of the tool–workpiece system were obtained. In the range of feed 0.03–0.18 mm/rev, the values of the standard deviation of relative displacements in the x-axis were obtained in the range of 0.36–0.78 μm for the insert with an edge radius of rn = 48.8 μm. As a result of the work, it was determined that for the feed value of 0.12 mm/rev for all inserts, the relative displacements are the smallest. As the final effect, the formula for forecasting the Ra roughness parameter was presented. 相似文献
BACKGROUND: Tiotropium, a once-daily anticholinergic, and salmeterol represent two inhaled, long-acting bronchodilators from different pharmacologic classes. A trial was designed to examine the efficacy and safety of both compounds with multiple outcome measures, including lung function, dyspnea, and health-related quality of life (HRQoL) in patients with COPD. METHODS: A 6-month, randomized, placebo-controlled, double-blind, double-dummy, parallel-group study of tiotropium, 18 microg once daily via dry-powder inhaler, compared with salmeterol, 50 microg bid via metered-dose inhaler, was conducted in patients with COPD. Efficacy was assessed by 12-h monitoring of spirometry, transition dyspnea index (TDI), and the St. George's Respiratory Questionnaire (SGRQ). RESULTS: A total of 623 patients participated (tiotropium, n= 209; salmeterol, n = 213; and placebo, n = 201). The groups were similar in age (mean, 65 years), gender (75% men), and baseline FEV(1) (mean, 1.08 +/- 0.37 L; percent predicted, 40 +/- 12% [+/- SD]). Compared with placebo treatment, the mean predose morning FEV(1) following 6 months of therapy increased significantly more for the tiotropium group (0.14 L) than the salmeterol group (0.09 L; p < 0.01). The average FEV(1) (0 to 12 h) for tiotropium was statistically superior to salmeterol (difference, 0.08 L; p < 0.001). Tiotropium improved TDI focal score by 1.02 U compared with placebo (p = 0.01), whereas there was no significant change in TDI focal score with salmeterol (0.24 U). Tiotropium was superior to salmeterol in improving TDI focal score (p < 0.05). At 6 months, the mean improvement in SGRQ total score vs baseline was tiotropium, - 5.14 U (p < 0.05 vs placebo); salmeterol, - 3.54 U (p = 0.4 vs placebo); and placebo, - 2.43 U. A statistically higher proportion of patients receiving tiotropium achieved at least a 4-U change in SGRQ score compared to patients receiving placebo. Both active drugs reduced the need for rescue albuterol (p < 0.0001). CONCLUSIONS: Tiotropium once daily produces superior bronchodilation, improvements in dyspnea, and proportion of patients achieving meaningful changes in HRQoL compared to twice-daily salmeterol in patients with COPD. 相似文献
The immune system constitutes an important first-line defence against malignant transformation. However, cancer mediated immunosuppression inactivates the mechanisms of host immune surveillance. Cancer cells shut down anti-cancer immunity through direct cell–cell interactions with leukocytes and through soluble factors, establishing an immunosuppressive environment for unimpeded cancer growth. The composition of the immunosuppressive microenvironment in breast tumours is not well documented. To address this question, selected immunosuppressive factors were analyzed in tumour specimens from 33 breast cancer patients after surgery. The mRNA expression of selected genes was quantified in fresh tumour samples. Tumour infiltrating leukocytes were characterized by flow cytometry to identify regulatory T cells, myeloid derived suppressor cells, and type 2 macrophages. Statistical analysis revealed several interesting correlations between the studied parameters and clinical features. Overall, a surprisingly high degree of heterogeneity in the composition of the immunosuppressive environment was found across all breast cancer samples which adds to the complexity of this disease. The influence of the hypoxia inducible factors (HIFs) on the immune microenvironment was also addressed. The level of HIFs correlated with hormone receptor status and the expression of several immunosuppressive molecules. Targeting HIFs might not only sensitize breast tumours for radiation and chemotherapies but also interfere with cancer immunosuppression. 相似文献
A combination of crash cushion and end-terminal, hybrid energy absorbing devices have been in use worldwide for a few years already. They include SafeEnd, a system Poland has recently introduced. Some road authorities have raised concerns as regards the operating conditions of the devices and how they work together with safety barriers. The objective of this research is to clarify the concerns and answer the following questions: (1) Can SafeEnd devices be used as hybrid devices and combine the roles of end-terminal and crash cushion placed before an obstacle? (2) What should be the rules for installing crash cushions at diverging roads and at the start of an off-ramp? The article presents characteristics of SafeEnd devices, defines the doubts raised by road safety auditors, discusses the results of field and numerical tests of the devices and explains the design principles for interchange ramps where crash cushions are required. The study results have helped to answer the research questions: SafeEnd devices fulfil the role of end-terminal and crash cushion, it is possible to make them more visible and principles have been defined for how the devices should be used at road interchanges. Further research should help to define general principles of deploying road restraint systems such as crashworthy terminals, crash cushions or hybrid devices. 相似文献