FX Systems Research Articles

Biocompatibility and degradation comparisons of four biodegradable copolymeric osteosynthesis systems used in maxillofacial surgery: A goat model with four years follow-up.

Applying biodegradable osteosyntheses avoids the disadvantages of titanium osteosyntheses. However, foreign-body reactions remain a major concern and evidence of complete resorption is lacking. This study compared the physico-chemical properties, histological response and radiographs of four copolymeric biodegradable osteosynthesis systems in a goat model with 48-months follow-up. The systems were implanted subperiosteally in both tibia and radius of 12 Dutch White goats. The BioSorb FX [poly(70LLA-co-30DLLA)], Inion CPS [poly([70–78.5]LLA-co-[16–24]DLLA-co-4TMC)], SonicWeld Rx [poly(DLLA)], LactoSorb [poly(82LLA-co-18GA)] systems and a negative control were randomly implanted in each extremity. Samples were assessed at 6-, 12-, 18-, 24-, 36-, and 48-month follow-up. Surface topography was performed using scanning electron microscopy (SEM). Differential scanning calorimetry and gel permeation chromatography were performed on initial and explanted samples. Histological sections were systematically assessed by two blinded researchers using (polarized) light microscopy, SEM and energy-dispersive X-ray analysis. The SonicWeld Rx system was amorphous while the others were semi-crystalline. Foreign-body reactions were not observed during the complete follow-up. The SonicWeld Rx and LactoSorb systems reached bone percentages of negative controls after 18 months while the BioSorb Fx and Inion CPS systems reached these levels after 36 months. The SonicWeld Rx system showed the most predictable degradation profile. All the biodegradable systems were safe to use and well-tolerated (i.e., complete implant replacement by bone, no clinical or histological foreign body reactions, no [sterile] abscess formation, no re-interventions needed), but nanoscale residual polymeric fragments were observed at every system's assessment.

Hybrid closed-loop therapy: Where are we in 2021?

Hybrid closed-loop systems are characterized by the coexistence of algorithm-driven automated insulin delivery combined with manual mealtime boluses. Used correctly, these insulin delivery systems offer better glucose control and reduced risk of hypoglycaemia and represent the most advanced form of insulin delivery available for people with type 1 diabetes. The aim of this paper was to compare the currently available commercial hybrid closed-loop systems in the UK: the Medtronic 670G/780G, Tandem t:slim X2 Control IQ and CamAPS FX systems. The Medtronic 670G/780G systems use Guardian 3 sensor (7-day use, two to four calibrations per day), while Tandem and CamAPS systems use the calibration-free Dexcom G6 sensor (10 days). The CamAPS system is available as an android app, whereas the other two systems have the algorithm embedded in the insulin pump. During pivotal studies, depending on the study population and baseline glycated haemoglobin level, these systems achieve a time spent in the target range 3.9 to 10 mmol/L (70 to 180 mg/dL) of 65% to 76% with low burden of hypoglycaemia. All three systems allow a higher glucose target for announced exercise, while the Tandem system offers an additional night-time tighter target. The CamAPS system offers fully customizable glucose targets and is the only system licensed for use during pregnancy. Additional education is required for both users and healthcare professionals to harness the best performance from these systems as well as to troubleshoot when "automode exits" occur. We provide consensus recommendations to develop pragmatic pathways to guide patients, clinicians and commissioners in making informed decisions on the appropriate use of the diabetes technology.

Comparative evaluation of BACTEC FX, BacT/ALERT 3D, and BacT/ALERT VIRTUO automated blood culture systems using simulated blood cultures

ABSTRACT Background To evaluate the performance of BACTEC FX, BacT/ALERT 3D, and VIRTUO systems using simulated blood culture (BC). Methods Two experimental designs based on ‘with’ or ‘without’ added trough antibiotic concentrations in bottles were implemented. Results For the experiment A, A shorter time to detection (TTD) was observed for most of organisms (17/22) in VIRTUO system. VIRTUO system was also faster than 3D and FX systems no matter in aerobic and anaerobic bottles. The anaerobic bottles had faster detection than aerobic bottles in 3D system (13.68 h vs 15.36 h, P < 0.001) and VIRTUO system (10.30 h vs 12.46 h, P = 0.001) but not in FX system (P = 0.38). When antibiotics were present, the bacterial recovery rate (RR) of FX, 3D and VIRTUO systems were 64.10% (50/78), 58.97% (46/78) and 43.59% (34/78), respectively (P = 0.027). the bacterial RR of various bottles were as follows: BPA vs. FA vs. SA [84.44%(38/45) vs. 55.56%(25/45) vs. 42.22(19/45), P < 0.001]; BFN vs. FN vs. SN [36.36%(12/33) vs. 63.64%(21/33) vs.45.45%(15/33), P = 0.078]. Conclusions The VIRTUO system allowed faster growth detection for most of organisms compared with FX and 3D systems. When antibiotics were present, the bottles containing antibiotic-binding agent showed better bacterial RR, especially in BACTEC Plus Aerobic/F bottles.

In vitro Evaluation of BACT/ALERT® VIRTUO®, BACT/ALERT 3D®, and BACTEC™ FX Automated Blood Culture Systems for Detection of Microbial Pathogens Using Simulated Human Blood Samples

Blood culture (BC) is still the standard for diagnosing bloodstream infections (BSIs), especially those caused by bacteria and fungi. Infection-complicating sepsis or septic shock often occurs at BSI onset, making necessary to improve the diagnostic yield of positive BCs. Among the BC systems currently available, the BACT/ALERT® VIRTUO® (VIRTUO) system has been developed to shorten time to detection (TTD) of positive BCs. In this study, we assessed TTD for 330 clinically relevant species including 14 Gram-positive, 14 Gram-negative, and 5 yeast isolates in spiked human blood samples that were tested in parallel with VIRTUO BACT/ALERT® 3D (BTA3D) and BACTEC™ FX (BACTEC) systems. We inoculated 30 colony-forming unit (CFU) from each microbial suspension into BACT/ALERT® Plus or BACTEC™ Plus (aerobic/anaerobic or pediatric) BC bottles, and we used two different blood volumes to simulate, respectively, the BCs collected from adult and pediatric patients. Of 2,610 bottles tested, 2,600 (99.6%) signaled positive in the three systems. Only the BACTEC system did not detect Staphylococcus lugdunensis isolates in anaerobic bottles. Among adult simulated cultures, the median TTD was significantly shorter for aerobic/anaerobic bottles incubated in VIRTUO (11.6 h and 10.1 h) compared to bottles incubated in either BTA3D (13.3 and 12.3 h) or BACTEC (13.5 and 12.2 h) system. Among pediatric simulated cultures, the median TTD was significantly shorter for bottles incubated in VIRTUO (11.2 h) compared to bottles incubated in either the BTA3D (13.0 h) or BACTEC (12.5 h) system. Compared to BTA3D and/or BACTEC systems, VIRTUO allowed faster growth detection for most of the 33 microbial species tested. Notable examples were Salmonella spp. (7.4 h by VIRTUO vs. 10.1 h and 9.2 h by either BTA3D or BACTEC) and Streptococcus agalactiae (8.1 h by VIRTUO vs. 10.3 and 9.4 h by either BTA3D or BACTEC). The few notable exceptions included Stenotrophomonas maltophilia and some Candida species. Together, these findings confirm that VIRTUO has greater potential of improving the laboratory detection of bacteremia and fungemia than the progenitor BTA3D or the competitor BACTEC system.

Delta neutrophil index discriminates true bacteremia from blood culture contamination

BackgroundDelta neutrophil index (DNI) has been reported to be useful in the diagnosis of sepsis. We evaluated the role of DNI for differentiating true bacteremia from blood contamination and compared the DNI value with previously validated markers such as procalcitonin (PCT) and C-reactive protein (CRP). MethodsThe blood culture positive group was subdivided into true bacteremia (n=199) and contamination (n=158). The blood cultures were incubated in the BacT/Alert 3D (bioMérieux, Marcyl’Etoile, France) and BACTEC FX (Becton Dickinson, Sparks, MD, USA) systems for 5days. Data of complete blood cell count were collected from an automatic cell analyzer (ADVIA2120 Hematology System, Siemens Healthcare Diagnostics) to calculate DNI. ResultsConcentrations for DNI, PCT, and CRP were significantly higher in the true bacteremia group. When the gram-positive and gram-negative infections were compared among true bacteremia, only PCT was increased significantly in GNB bacteremia. DNI levels were well correlated with PCT (r=0.564, P<0.0001) and CRP (r=0.344, P<0.001) using the Spearman test among the culture positive bacteremia. The area under the ROC curve was 0.75 for PCT, 0.69 for CRP, and 0.69 for DNI. ConclusionsWe demonstrated the usefulness of DNI in differentiating true bacteremia from contamination in patients with a positive blood culture.

The role of F-doping and oxygen vacancies on the superconductivity in SmFeAsOcompounds

By investigating the F-doping effect in theSmFeAsO1−xFx,SmFeAsO1−xF0.20 and SmFeAsO0.90Fx systems as well as the oxygen vacancy effect in theSmFeAsO1−y superconductors, we obtained the following results: (a) the substitution range of F for oxygen in theSmFeAsO1−xFx system prepared by the ambient pressure method is0≤x≤0.125;(b) F cannot substitute for oxygen in samples without oxygen vacancies; (c) the oxygen-deficientSmFeAsO1−y superconductor cannot be prepared by the ambient pressure method; and (d)F-doping and oxygen vacancies both lead to lattice shrinkage. Oxygen-deficientSmFeAsO0.85 andF-doped SmFeAsO0.85F0.15 prepared by the high pressure method have higher superconducting transition temperature comparedto SmFeAsO0.85F0.15 prepared by the ambient pressure method.

A large-scale, high-efficiency and low-cost platform for structural genomics studies

A large-scale, high-efficiency and low-cost platform based on a Beckman Coulter Biomek FX and custom-made automation systems for structural genomics has been set up at Peking University, Beijing, People's Republic of China. This platform has the capacity to process up to 2000 genes per year for structural and functional analyses. Bacillus subtilis, a model organism for Gram-positive bacteria, and Streptococcus mutans, a major pathogen of dental caries, were selected as the main targets. To date, more than 470 B. subtilis and 1200 S. mutans proteins and hundreds of proteins from other sources, including human liver proteins, have been selected as targets for this platform. The selected genes are mainly related to important metabolism pathways and/or have potential relevance for drug design. To date, 40 independent structures have been determined; of these 11 are in the category of novel structures by the criterion of having less than 30% sequence identity to known structures. More than 13 structures were determined by SAD/MAD phasing. The macromolecular crystallography beamline at the Beijing Synchrotron Radiation Facility and modern phasing programs have been crucial components of the operation of the platform. The idea and practice of the genomic approach have been successfully adopted in a moderately funded structural biology program and it is believed this adaptation will greatly improve the production of protein structures. The goal is to be able to solve a protein structure of moderate difficulty at a cost about US 10,000 dollars.

Scaling ionic partition scheme for estimate of electron correlation energy of AB polar covalent molecules

Based on the calculation of pair correlation energy contributions of FX (X=OH, NH 2, CH 3) systems and the comparison of three partition schemes, the total correlation energies of these AB type covalent molecules have been approximated using the simple scaling ionic partition scheme. Incorporating our early works on strong ionic compounds MA and A 2 symmetric molecules, the general formula is summarized to estimate the total correlation energy for different kinds of chemical bonding systems. Comparison of the ratio of scaling coefficients for MA compounds, AB type and A 2 symmetric molecules shows that the ratio depends on the ionic property of the system.

State mixing and the preferred jahn-teller coupling in cubic fx systems

The effect of the inclusion of state mixing is examined for the calculation of the Jahn-Teller coupling constants of the two Γ 8 states of f 1 systems in O h symmetry, both ML 6 and ML 8 species being considered. For the values of the spin-orbit coupling constants and ligand-field splitting parameters usually encountered, the results differ significantly from the strong-field limit values, but only slightly from those of the weak-field limit. For ML 6 systems the available estimates for the e λ and ∂ e λ ∂R parameters of the angular overlap model, together with the appropriate force-constant ratios, predict dominant coupling to the ϵ g mode for the Γ 8( 2 F 5 2 : 2 T 2u) level, whilst coupling to the τ 2g mode should prevail for the Γ 8( 2 F 7 2 : 2 T 1u) state. For ML 8 species the calculations similarly lead to the expectation of predominant τ 2g(δ) coupling for Γ 8( 2 F 5 2 : 2 T 1u), with prevailing ϵ g coupling for Γ 8 ( 2 F 7 2 : 2 T 2u). The results suggest the general adequacy of the weak-field limit results for cubic f x systems and, as an example, the T 1 and T 2 states for 3 H 4 of f 2, O h ML 6, systems are thus briefly treated.

Jahn-Teller stabilization energies for fx systems: angular-overlap calculations for octahedral systems in the weak-field scheme

Jahn-Teller stabilization energies for fx systems: angular-overlap calculations for octahedral systems in the weak-field scheme