Search

Purpose/objective(s): A novel therapeutic machine that combines PET, fan beam kVCT and linear accelerator to support real-time PET-guided treatment, termed biology-guided radiotherapy (BgRT). This study reports the positioning accuracy, image quality, and dose commissioning of the kVCT imaging system of the first clinical BgRT machine at our institute.Materials/methods: The helical fan-beam kVCT subsystem consists of an X-ray tube with a voltage of 120kV and a 16-row GOS Ceramic Scintillator detector. The gantry rotation speed is 60 rpm. The tube currents are 45, 67, 133mA for 0.5 pitch; 100, 150, and 300mA for 0.5 pitch; 267 and 400mA for 1.333 pitch. The image slice thickness is 1.25mm with a field of view of 500mm and a resolution of 512 × 512. A ball-cube phantom was used to test the positioning accuracy of the kVCT subsystem with respect to the setup laser and MV beam. Catphan504 phantom was imaged with 0.5 pitch and 150mAs to test the kVCT image quality of the BgRT system, including the uniformity, noise, HU constancy, spatial resolution, geometric distortion, slice thickness, and low contrast visibility and detectability using the PIPSproTM software. The RTI MAS-2 and Piranha detectors were used to verify the accuracy of the mA and voltage. The CTDI dose was measured using a CTDI phantom and a Standard Imaging A101 pencil chamber.Results: The localization error of the ball cube phantom was -0.8, 0.9, and 0.3mm in IEC x, y, and z directions, respectively. For the Catphan504 tests, the vertical and horizontal uniformities were 0.926 and 0.857, respectively. The HU constancy tests of the air, water, polystyrene, acrylic, Delrin, Teflon were all within 40HU to the expected values. The modulation transfer function test results were 0.467, 0.528, and 0.595 lp/mm for F50, F40, and F30, respectively, which showed a comparable spatial resolution to regular CT simulators. The geometric distortion was 0.12mm and slice thickness inaccuracy was 0.13mm. The low contrast detectability was 0.734. The measured mA and voltage were within 5% of the nominal setting of 120 kV and 150 mA. The CTDIw was less than 1.4 cGy for body and 3 cGy for head with a protocol of 120 kVp, 150 mAs, and 1.25 mm slice thickness.Conclusion: This evaluation represents the kVCT characteristics of the novel BgRT system with architecture designed to accommodate CT, PET and a LINAC. The image quality and HU constancy are comparable to our CT simulators and is a useful tool for online adaptive radiotherapy. The commissioning data will serve as a standard for units installed at future clinical sites. [ABSTRACT FROM AUTHOR]

This study aims to improve the efficiency and uneven texture of conventional magnetic abrasive finishing (MAF) of the inner surface of alumina ceramic tubes by changing the trajectory of a magnetic abrasive brush (MAB), presenting a new technology of ultrasonic-assisted magnetic abrasive finishing (UAMAF). The experiments compare the surface quality and material removal between MAF and UAMAF and examine the effects of workpiece speed and frequency on the surface roughness and material removal. The results show that the UAMAF has made the finishing of the inner surface of alumina ceramic tubes efficiently and precisely come true. By altering the test conditions, after 50 min processing, the processing achieves the surface roughness of R as fine as 0.03 μm and increases the material removal from 295 to 485 mg. The study also reveals that the frequency and workpiece speed improve the processing in varied degrees and have different finishing characteristics of the surface roughness and material removal. [ABSTRACT FROM AUTHOR]

Summary Background To determine the relationship between the serum concentration of trefoil factor 3 (TFF3) and gastrointestinal failure (GIF) in pediatric critical illness in order to provide knowledge for disease management. Materials and methods We enrolled 137 cases and divided them into three groups, including a control group (group A), critical illness without GIF (group B), and critical illness with GIF (group C). The serum TFF3 concentration was determined by ELISA and compared among the groups. Results Serum TFF3 concentrations measured before the occurrence of GIF in group C were significantly higher than in groups A and B ( P < 0.01). Under the conditions of GIF in group C, serum TFF3 concentration was significantly related to the gastrointestinal tract function score ( r = −0.712). Cox's proportional hazards model analysis showed that the serum TFF3 concentrations at the time of occurrence of GIF, and 48 hours later, could be used as prognostic factors in critically ill pediatric patients with GIF ( r = 1.443 and 1.872, respectively). Conclusion TFF3 may play an important role in predicting GIF in pediatric critical illness and has a protective function in the mucosal repair process. [ABSTRACT FROM AUTHOR]

Customizable endonucleases such as transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) enable rapid generation of mutant strains at genomic loci of interest in animal models and cell lines. With the accelerated pace of generating mutant alleles, genotyping has become a rate-limiting step to understanding the effects of genetic perturbation. Unless mutated alleles result in distinct morphological phenotypes, mutant strains need to be genotyped using standard methods in molecular biology. Classic restriction fragment length polymorphism (RFLP) or sequencing is labor-intensive and expensive. Although simpler than RFLP, current versions of allele-specific PCR may still require post-polymerase chain reaction (PCR) handling such as sequencing, or they are more expensive if allele-specific fluorescent probes are used. Commercial genotyping solutions can take weeks from assay design to result, and are often more expensive than assembling reactions in-house. Key components of commercial assay systems are often proprietary, which limits further customization. Therefore, we developed a one-step open-source genotyping method based on quantitative PCR. The allele-specific qPCR (ASQ) does not require post-PCR processing and can genotype germline mutants through either threshold cycle (Ct) or end-point fluorescence reading. ASQ utilizes allele-specific primers, a locus-specific reverse primer, universal fluorescent probes and quenchers, and hot start DNA polymerase. Individual laboratories can further optimize this open-source system as we completely disclose the sequences, reagents, and thermal cycling protocol. We have tested the ASQ protocol to genotype alleles in five different genes. ASQ showed a 98-100% concordance in genotype scoring with RFLP or Sanger sequencing outcomes. ASQ is time-saving because a single qPCR without post-PCR handling suffices to score genotypes. ASQ is cost-effective because universal fluorescent probes negate the necessity of designing expensive probes for each locus. [ABSTRACT FROM AUTHOR]

Spallation Neutron Source ramps to higher power levels that can be sustained with high availability. The goal is 1.4MWdespite a compromised radio frequency quadrupole (RFQ), which requires higher radio frequency power than design levels to approach the nominal beam transmission. Unfortunately at higher power the RFQ often loses its thermal stability, a problem apparently enhanced by beam losses and high influxes of hydrogen. Delivering as much H- beam as possible with the least amount of hydrogen led to plasma outages. The root cause is the dense 1-ms long ~55-kW 2-MHz plasma pulses reflecting ~90% of the continuous ~300 W, 13-MHz power, which was mitigated with a 4-ms filter for the reflected power signal and an outage resistant, slightly detuned 13-MHz match. Lowering the H2 gas also increased the H- beam current to ~55 mA and increased the RFQ transmission by ~7% (relative). [ABSTRACT FROM AUTHOR]

The Spallation Neutron Source H- ion source is operated with a pulsed 2-MHz RF (50-60 kW) to produce the 1-ms long, ~50 mA H- beams at 60 Hz. A continuous low power (~300 W) 13.56-MHz RF plasma, which is initially ignited with a H2 pressure bump, serves as starter plasma for the pulsed high power 2-MHz RF discharges. To reduce the risk of plasma outages at lower H2 flow rates which is desired for improved performance of the following radio frequency quadrupole, the 13.56-MHz RF matching network was characterized over a broad range of its two tuning capacitors. The H-α line intensity of the 13.56-MHz RF plasma and the reflected power of the 13.56-MHz RF were mapped against the capacitor settings. Optimal tunes for the maximum H-α intensity are consistent with the optimal tunes for minimum reflected power. Low limits of the H2 flow rate not causing plasma outages were explored within the range of the map. A tune region that allows lower H2 flow rate has been identified, which differs from the optimal tune for global minimum reflected power that was mostly used in the past. [ABSTRACT FROM AUTHOR]

Cell division relies on coordinated regulation of the cell cycle. A process including a well-defined series of strictly regulated molecular mechanisms involving cyclin-dependent kinases, retinoblastoma protein, and polo-like kinases. Dysfunctions in cell cycle regulation are associated with disease such as cancer, diabetes, and neurodegeneration. Compartmentalization of cellular signaling is a common strategy used to ensure the accuracy and efficiency of cellular responses. Compartmentalization of intracellular signaling is maintained by scaffolding proteins, such as A-kinase anchoring proteins (AKAPs). AKAPs are characterized by their ability to anchor the regulatory subunits of protein kinase A (PKA), and thereby achieve guidance to different cellular locations via various targeting domains. Next to PKA, AKAPs also associate with several other signaling elements including receptors, ion channels, protein kinases, phosphatases, small GTPases, and phosphodiesterases. Taking the amount of possible AKAP signaling complexes and their diverse localization into account, it is rational to believe that such AKAP-based complexes regulate several critical cellular events of the cell cycle. In fact, several AKAPs are assigned as tumor suppressors due to their vital roles in cell cycle regulation. Here, we first briefly discuss the most important players of cell cycle progression. After that, we will review our recent knowledge of AKAPs linked to the regulation and progression of the cell cycle, with special focus on AKAP12, AKAP8, and Ezrin. At last, we will discuss this specific AKAP subset in relation to diseases with focus on a diverse subset of cancer. [ABSTRACT FROM AUTHOR]

Background and purpose Low serum levels of vitamin D have been associated with depression in non-stroke subjects. Our aim was to examine the possible association between serum vitamin D levels and the development of post-stroke depression ( PSD). Methods In total, 189 patients with acute ischaemic stroke were consecutively recruited. Serum levels of 25-hydroxyvitamin D [25( OH) D] were measured by competitive protein-binding assay within 24 h after admission. The 17-item Hamilton Depression Scale was used for screening for the existence of depressive symptoms at 1 month after stroke. Patients with a Hamilton Depression Scale score of ≥7 were given the Structured Clinical Interview of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, for diagnosis of PSD. Meanwhile, 100 healthy control subjects were also recruited and underwent measurement of 25( OH) D. Results Fifty-five patients (29.1%) were diagnosed as having PSD at 1 month. Serum vitamin D levels within 24 h after admission were significantly lower in both non- PSD patients and PSD patients than in normal controls. PSD patients had significantly lower vitamin D than non- PSD patients. Serum vitamin D levels (≤37.1 and ≥64.1 nmol/l) were independently associated with the development of PSD (odds ratio 8.824, 95% confidence interval 2.011-38.720, P = 0.004, and odds ratio 0.127, 95% confidence interval 0.022-0.718, P = 0.020, respectively). Conclusions Serum vitamin D levels within 24 h after admission are found to be associated with PSD and may predict its development at 1 month post-stroke. [ABSTRACT FROM AUTHOR]

This paper examines whether the displacement of A-pillar top-end of vehicle in CRIS (Controlled Rollover Impact System) is related to roof strength. Current roof strength tests are not relevant to current rollover accident trends because the test condition is quasi-static. The ADAMS model of the vehicle was developed in this paper to compare the results obtained in the different test condition. This model consists of deformable upper-body members (A/B/C- pillars, Roof-bows, Side roof-rails) and a rigid under-body. The collapse behavior is considered by computing the characteristics of deformable members. This model was used to simulate quasi-static roof crush test and CRIS rollover test. The roof crush test condition (quasi-static) was adopted in accordance with the IIHS test protocol. The CRIS rollover test condition is selected to represent the trip-over type rollover given that a dynamic test protocol has yet to be developed. L orthogonal array is adopted for the DOE (Design of Experiment) analysis. The results show that the dominant member affecting roof crush resistance differs from the dominant member in dynamic test. Hence, the dynamic test should be used to evaluate the roof strength of vehicles. Nonetheless, roof crush resistance remains the minimum requirement for ensuring driver and passenger safety in the event of a roll-over accident. [ABSTRACT FROM AUTHOR]

In this study, the evolutions of impedance and bio-indicators (total aerobic count ( TAC), total volatile base nitrogen ( TVB-N) and pH) of meat freshness during storage at 4 °C were investigated and compared. The influence of electrode configurations, frequencies and directions of applied electric fields on impedance measurement was considered. Good relationships between measured impedance and bio-indicators were obtained, with R2 ranging from 0.758 to 0.992, RMSE from 0.11 to 0.57 for TAC and R2 ranging from 0.636 to 0.989, RMSE from 0.29 to 1.68 for TVB-N. Bar and ring electrodes had better performance as compared to needle electrodes. Effects of frequency on impedance were important from 20 Hz to 200 kHz and diminished in the higher ranges. Impedance generally exhibited better correlations with TAC, TVB-N at high frequency than at low frequency. The findings demonstrated that impedance measurement could be a viable, rapid method to assess the quality of stored pork meat. [ABSTRACT FROM AUTHOR]

With samples made of composite prepared by adding nickel powder (NP) as a functional filler into cement based material, experiments are carried out to study the piezoresistivity of this NP filled cement based composite (NPCC) under single compressive loading to destruction and within elastic regime. Experimental results indicate that the electrical resistivity of NP filled cement based composite exhibits a three-stage variation trend of fast decrease, slow decrease and steady increase as compressive stress and strain increase under single compressive loading to destruction, and its fractional change goes up to 79·28% maximum. The electrical resistivity of the piezoresistive NPCC decreases 74·67% within elastic regime, and the sensitivity of this composite to compressive stress, compressive strain and transverse tensile strain goes up to 0·158 MPa-1, 1228·2 and 7580 maximum respectively. It therefore can be concluded that the developed piezoresistive NPCC has high sensitivity to stress/strain. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons ( PAHs) are among the most toxic air pollutants in China. However, because there are unsubstantial data on indoor and outdoor particulate PAHs, efforts in assessing inhalation exposure and cancer risk to PAHs are limited in China. This study measured 12 individual PAHs in indoor and outdoor environments at 36 homes during the non-heating period and heating period in 2009. Indoor PAH concentrations were comparable with outdoor environments in the non-heating period, but were lower in the heating period. The average indoor/outdoor ratios in both sampling periods were lower than 1, while the ratios in the non-heating period were higher than those in the heating period. Correlation analysis and coefficient of divergence also verified the difference between indoor and outdoor PAHs, which could be caused by high ventilation in the non-heating period. To support this conclusion, linear and robust regressions were used to estimate the infiltration factor to compare outdoor PAHs to indoor PAHs. The calculated infiltration factors obtained by the two models were similar in the non-heating period but varied greatly in the heating period, which may have been caused by the influence of ventilation. Potential sources were distinguished using a diagnostic ratio and a mixture of coal combustion and traffic emission, which are major sources of PAHs. [ABSTRACT FROM AUTHOR]

The casting defects existed in a directional fully lamellar TiAl alloy Ti-47.5Al-2.5V-1.0Cr-0.2Zr (at.%). The proper hot isostatic pressing (HIP) was used to decrease the size or change the shape of the casting defects under the condition to remain the structure of the alloy unchanged. The effect of the remained defects on the high cycle fatigue properties of the alloy was studied in the present investigation. The result showed that two kind defects of the bulk micro-porosity and the bridged porosity interface existed in the alloy after the HIP. It has been found that the bulk micro-porosity defects affect the high cycle fatigue life at 750°C more significantly compared with the bridged porosity interface defects. And the effect of the defects on the fatigue life was related to the defect size, shape and location. The fatigue life decreased with the increasing defect area/size and the decreasing curvature radius of the defect because of the stress concentration at the defect tip. The fatigue life of the specimens with the defects at the subsurface was significantly longer than that of the surface. [ABSTRACT FROM AUTHOR]

Under quasi-static uniaxial compression, inserting aluminum foams into the interstices of a metallic sandwich panel with corrugated core increased significantly both its peak crushing strength and energy absorption per unit mass. This beneficial effect diminished however if the foam relative density was relatively low or the compression velocity became sufficiently high. To provide insight into the vaiying role of aluminum foam filler with increasing compression velocity, the crushing response and collapse modes of all metallic corrugate-cored sandwich panels filled with close-celled aluminum foams were studied using the method of finite elements (FEs). The constraint that sandwich panels with and without foam filling had the same total weight was enforced. The effects of plastic hardening and strain rate sensitivity of the strut material as well as foam!strut interfacial debonding were quantified. Three collapse modes (quasi-static, transition, and shock modes) were identified, corresponding to different ranges of compression velocity. Strengthening due to foam insertion and inertial stabilization both acted to provide support for the struts against buckling. At relatively low compression velocities, the struts were mainly strengthened by the surrounding foam; at high compression velocities, inertia stabilization played a more dominant role than foam filling. [ABSTRACT FROM AUTHOR]

D e novo synthesis of threonine from aspartate occurs via the β-aspartyl phosphate pathway in plants, bacteria and fungi. However, the T rypanosoma brucei genome encodes only the last two steps in this pathway: homoserine kinase ( HSK) and threonine synthase. Here, we investigated the possible roles for this incomplete pathway through biochemical, genetic and nutritional studies. Purified recombinant Tb HSK specifically phosphorylates L-homoserine and displays kinetic properties similar to other HSKs. HSK null mutants generated in bloodstream forms displayed no growth phenotype in vitro or loss of virulence in vivo. However, following transformation into procyclic forms, homoserine, homoserine lactone and certain acyl homoserine lactones ( AHLs) were found to substitute for threonine in growth media for wild-type procyclics, but not HSK null mutants. The tsetse fly is considered to be an unlikely source of these nutrients as it feeds exclusively on mammalian blood. Bioinformatic studies predict that tsetse endosymbionts possess part (up to homoserine in W igglesworthia glossinidia) or all of the β-aspartyl phosphate pathway ( S odalis glossinidius). In addition S . glossinidius is known to produce 3-oxohexanoylhomoserine lactone which also supports trypanosome growth. We propose that T . brucei has retained HSK and threonine synthase in order to salvage these nutrients when threonine availability is limiting. [ABSTRACT FROM AUTHOR]

Kawasaki disease (KD) is the leading cause of acquired coronary disease in children and may lead to subsequent myocardial ischemia and infarction. Because coronary computed tomographic angiography (CTA) is the most sensitive noninvasive test in patients with atherosclerosis, the aim of this study was to retrospectively evaluate coronary CTA performed in patients with KD for aneurysm, stenosis, and calcified and noncalcified coronary artery disease (CAD). Clinical histories and prior stress and imaging test results were reviewed. Thirty-two patients underwent coronary CTA for KD, and 385 coronary segments were evaluated. Twenty-three of 32 patients had ≥1 diseased coronary segment. There were 20 aneurysms, 7 lesions, and 75 segments (20%) with nonobstructive CAD (16% noncalcified, 2% calcified, and 2% mixed). All nonobstructive and obstructive CAD was in patients with histories of acute-phase coronary artery dilatation or aneurysm (echocardiographic z score 4 to 44), and were almost always associated with normal stress imaging test results on followup. No lesion or CAD was found in coronary computed tomographic angiographic studies performed in a control group referred for other indications (n = 32,422 segments evaluated). The median coronary computed tomographic angiographic dose-length product was 59 mGy cm (interquartile range 32 to 131), the median unadjusted radiation dose was 0.8 mSv (interquartile range 0.4 to 1.8), and the median age- and size-adjusted radiation dose was 1.3 mSv (interquartile range 0.7 to 2.3). In conclusion, high-risk patients with histories of KD had nonobstructive and obstructive CAD not visualized by other noninvasive imaging tests. In properly selected high-risk patients with KD, coronary CTA may identify a subset at increased risk for future coronary pathology who may benefit from medical therapy. [ABSTRACT FROM AUTHOR]

Highlights: [•] Metallic sandwich beams with empty and aluminum foam filled corrugated cores. [•] Quasi-static three-point bending tests were carried on the sandwich beams. [•] Aluminum foam filling led to dramatically increased bending resistance performance. [•] Bending stiffness, initial failure load, peak load, and failure modes were predicted. [•] Failure maps were constructed to reveal the failure mechanisms. [ABSTRACT FROM AUTHOR]

There is an unmet need for timely and reliable prediction of post-cardiac arrest (CA) clinical trajectories. We hypothesized that physiological time series (PTS) data recorded on the first day of intensive care would contribute significantly to discrimination of outcomes at discharge. Adult patients in the multicenter eICU database who were mechanically ventilated after resuscitation from out-of-hospital CA were included. Outcomes of interest were survival, neurological status based on Glasgow motor subscore (mGCS) and surrogate functional status based on discharge location (DL), at hospital discharge. Three machine learning predictive models were trained, one with features from the electronic health records (EHR), the second using features derived from PTS collected in the first 24 h after ICU admission (PTS 24), and the third combining PTS 24 and EHR. Model performances were compared, and the best performing model was externally validated in the MIMIC-III dataset. Data from 2216 admissions were included in the analysis. Discrimination of prediction models combining EHR and PTS 24 features was higher than models using either EHR or PTS 24 for prediction of survival (AUROC 0.83, 0.82 and 0.79 respectively), neurological outcome (0.87, 0.86 and 0.79 respectively), and DL (0.80, 0.78 and 0.76 respectively). External validation in MIMIC-III (n = 86) produced similar model performance. Feature analysis suggested prognostic significance of previously unknown EHR and PTS 24 variables. These results indicate that physiological data recorded in the early phase after CA resuscitation contain signatures that are linked to post-CA outcome. Additionally, they attest to the effectiveness of ML for post-CA predictive modeling. [ABSTRACT FROM AUTHOR]

A series of novel blue emitting KBaTmBPO (0.01 ≤ x ≤ 0.08) phosphors were synthesized by a solid-state reaction at a high temperature for the first time. The phase purity and photoluminescence properties were investigated by X-ray diffraction (XRD) and fluorescence spectroscopy (FS) measurements, respectively. The influence of the doping concentration of Tm on its relative emission intensity was investigated, and the critical distance was calculated. The as-prepared phosphor can be effectively excited with a 356-nm light, and exhibit blue emission at 457 nm with high color purity. The above work indicates this phosphor could be a potential candidate as blue emitting phosphor for application in white light-emitting diodes. [ABSTRACT FROM AUTHOR]

A RF-driven, Cs-enhanced H- ion source feeds the SNS accelerator with a high current (typically >50 mA), ~1.0 ms pulsed beam at 60 Hz. To achieve the persistent high current beam for several weeks long service cycles, each newly installed ion source undergoes a rigorous conditioning and cesiation processes. Plasma conditioning outgases the system and sputter-cleans the ion conversion surfaces. A cesiation process immediately following the plasma conditioning releases Cs to provide coverage on the ion conversion surfaces. The effectiveness of the ion source conditioning and cesiation is monitored with plasma emission spectroscopy using a high-sensitivity optical spectrometer. Plasma emission spectroscopy is also used to provide a means for diagnosing and confirming a failure of the insulating coating of the ion source RF antenna which is immersed in the plasma. Emissions of composition elements of the antenna coating material, Na emission being the most significant, drastically elevate to signal a failure when it happens. Plasma spectra of the developmental ion source with an AlN (aluminum nitrite) chamber and an external RF antenna are also briefly discussed. [ABSTRACT FROM AUTHOR]

Nine local dominant freshwater algal species, including green algae (Chlorella sp., Chlamydomonas sp. and Scenedesmus quadricauda), diatom (Navicula pelliculosa, Nitzschia palea Grunow and Synedra sp.), blue-green algae (Microcystis sp., Chroococcus sp. and Gloeocapsa sp.) were isolated from source water reservoirs and cultivated in the laboratory. The algal biomass was chlorinated (20 WC, pH 7, residual chlorine 2 mg L-1). Yields of chloroform, dichloroacetic acid, trichloroacetic acid, dichloroacetonitrile and trichloroacetonitrile and genotoxicity of the chlorinated solutions at eight chlorination intervals (0.5, 1, 2, 5, 10, 30, 60 and 120 min) were determined via SOSChromoTest and Comet assay. The results showed that green algae and diatom were more effective disinfection by-products (DBPs) precursors than blue-green algae. Genotoxicity was shown to be chlorination time-dependent, in agreement with our previous findings, suggesting that intermediate DBPs rather than trihalomethanes or haloacetic acids were major contributors to the genotoxicity of chlorinated solutions. [ABSTRACT FROM AUTHOR]

African trypanosomes are capable of both de novo synthesis and salvage of pyrimidines. The last two steps in de novo synthesis are catalysed by UMP synthase ( UMPS) - a bifunctional enzyme comprising orotate phosphoribosyl transferase ( OPRT) and orotidine monophosphate decarboxylase ( OMPDC). To investigate the essentiality of pyrimidine biosynthesis in Trypanosoma brucei, we generated a umps double knockout ( DKO) line by gene replacement. The DKO was unable to grow in pyrimidine-depleted medium in vitro, unless supplemented with uracil, uridine, deoxyuridine or UMP. DKO parasites were completely resistant to 5-fluoroorotate and hypersensitive to 5-fluorouracil, consistent with loss of UMPS, but remained sensitive to pyrazofurin indicating that, unlike mammalian cells, the primary target of pyrazofurin is not OMPDC. The null mutant was unable to infect mice indicating that salvage of host pyrimidines is insufficient to support growth. However, following prolonged culture in vitro, parasites regained virulence in mice despite retaining pyrimidine auxotrophy. Unlike the wild-type, both pyrimidine auxotrophs secreted substantial quantities of orotate, significantly higher in the virulent DKO line. We propose that this may be responsible for the recovery of virulence in mice, due to host metabolism converting orotate to uridine, thereby bypassing the loss of UMPS in the parasite. [ABSTRACT FROM AUTHOR]

A novel positive-polarity electrostatic precipitator ( ESP) was developed using an ionization stage (0.4 × 0.4 × 0.14 m3) with 16 carbon fiber ionizers in each channel and a collection stage (0.4 × 0.4 × 0.21 m3) with parallel metallic plates. The single-pass collection efficiency and clean air delivery rate ( CADR) were measured by standard tests using KCl particles in 0.25-0.35 μm. Performance was determined using the Deutsch equation and established diffusion and field charging theories and also compared with the commercialized HEPA filter-type air cleaner. Experimental results showed that the single-pass collection efficiency of the ESP ranged from 50 to 95% and decreased with the flow rate (10-20 m3/min), but increased with the voltage applied to the ionizers (6 to 8 kV) and collection plates (−5 to −7 kV). The ESP with 18 m3/min achieved a CADR of 12.1 m3/min with a voltage of 8 kV applied to the ionization stage and with a voltage of −6 kV applied to the collection stage. The concentration of ozone in the test chamber (30.4 m3), a maximum value of 5.4 ppb over 12 h of continuous operation, was much lower than the current indoor regulation (50 ppb). [ABSTRACT FROM AUTHOR]

Abstract: Scenario discovery offers a new means to characterize and communicate the information in computer simulation models under conditions of deep uncertainty. The approach first defines scenarios as the future states of world where a proposed policy fails to meet its goals and then uses statistical algorithms to find concise descriptions of such regions in large databases of simulation model results. Current scenario discovery applications rely on the Patient Rule Induction Method (PRIM), a user-interactive bump-hunting algorithm that identifies hyper-rectangular regions in the input space of the simulation model. While often successful, scenario discovery applications have been limited because in general a policy's vulnerabilities are not well described by the PRIM's hyper-rectangular regions. This study proposes and evaluates improved scenario discovery algorithms that address this challenge with a Principal Component Analysis (PCA)-based preprocessing step that transforms the original model input parameters so that PRIM can then identify high quality hyper-rectangular scenarios in the new rotated coordination system. We explore two versions. PCA-PRIM allows rotations among all uncertain model input parameters and CPCA-PRIM (for constrained PCA-PRIM) only allows rotations among parameters within user-specified domains. The latter may provide more useful information to users, who may find scenario axes described by linear combinations of related domain parameters more interpretable than combinations of dissimilar parameters. We run two sets of tests on the PCA-PRIM and CPCA-PRIM algorithms, the first using simulated test date and the second results from a model used in a previous RAND study of the cost-effectiveness of renewable energy portfolio standards. We find that the new algorithms produce higher quality scenarios than PRIM alone as evaluated by several important measures of merit. In the test data, PCA-PRIM produces improvements averaging 37 percent, and CPCA-PRIM averaging 14 percent, over PRIM alone. In the renewable energy policy case study, PCA-PRIM and CPCA-PRIM exhibit similar improvements of about 16 percent over PRIM, and CPCA-PRIM generates scenarios interpretable by, and that provide useful information to, decision makers. [Copyright &y& Elsevier]

Water-jet cavitation peening (WCP) is a new technology for the surface modification of metallic materials. The cavitation behavior in this process involves complex and changeable physics phenomena, such as high speed, high pressure, multiple phases, phase transition, turbulence, and unstable features. Thus, the cavitation behavior and impact-pressure distribution in WCP have always been key problems in this field. Numerous factors affect the occurrence of cavitation. These factors include flow-boundary conditions, absolute pressure, flow velocity, flow viscosity, surface tension, and so on. Among these factors, pressure and vapor fraction are the most significant. Numerical simulations are performed to determine the flow-field characteristics of both inside and outside the cavitating nozzle of a submerged water jet. The factors that influence the cavitation intensity of pressure are simulated. Fujifilm pressure-sensitive paper is used to measure the distribution of impact pressure along the jet direction during the WCP process. The results show that submerged cavitation jets can induce cavitation both inside and outside a conical nozzle and a convergent-divergent nozzle when the inlet pressure is 32 MPa. Moreover, the shock wave pressure induced by the collapse of the bubble group reaches up to 300 MPa. [ABSTRACT FROM AUTHOR]

Evaporation rates play a key role in evaporation crystallization and the drying of crystal products. Raman analysis was used to study the effect of the evaporation rate on the polymorphs of indomethacin at room temperature. The studied solvents were highly volatile ethanol, acetone, and ethyl acetate. The approach was based on a mass transfer model of evaporation, and experimental flux measurements were used for model evaluation. Evaporation rates from porous carriers were also investigated. The studied mesoporous silicon microparticles can be used in oral dosage forms of poorly soluble active pharmaceutical ingredients. Evaporation rates of dimethyl sulfoxide from a pure solvent, from indomethacin solutions, and from solutions containing microparticles were measured at 100 °C. An evaporation rate model of porous particles was used and the predicted results were compared with the experimental results obtained. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI) is progressing rapidly, and its application in the field of medicine is increasing.1 AI algorithms have been shown to be as accurate as dermatologists in classifying various skin diseases based on clinical images.2,3 Furthermore, AI can assist non-dermatologists in classifying skin conditions.4,5 A recent international online survey reported that most dermatologists agree that AI will change in dermatology.6 However, AI-driven changes will primarily affect future generations of medical doctors. When asked to select areas of educational importance, 76% selected the practical application of AI in medicine to be the most important, followed by medical ethics of AI (61%), AI theory (59%) and AI programming (44%). [Extracted from the article]

Purpose/objective(s): A biologically guided radiotherapy (BgRT) system was developed and equipped with a novel O-ring gantry Linac, positron emission tomography (PET) and computed tomography technologies. This architectural design is to support real-time PET-guided treatment, termed biology-guided radiotherapy. To reduce latency between PET data acquisition and radiation delivery, the BgRT system incorporates a fast-transitioning binary multi-leaf collimator (MLC) leaves sandwiched between a split-jaw. This study reports the dosimetric commissioning of the first clinical BgRT machines at our institution, and compared with the reference data provided by the manufacturer.Materials/methods: The dosimetric commissioning of the 6 MV flattening filter-free (FFF) photon beam was characterized using a 3D water phantom and diode detectors at a source to surface distance of 85 cm. In-air profiles of 40cm x 2cm field, 40cm x 1cm field, and various leaf combinations plus in water PDD data of 12 field sizes (1.25, 2.5, 5, 10, 20 and 40 cm MLC opened leaves with 1 and 2cm jaw settings) were acquired first for beam modeling. Additional longitudinal and transverse profile scans were performed for these 12 field sizes at the depth of 1.5, 5, 10, 15 and 20 cm to verify the beam model accuracy. The relative outputs factors were measured with the W2 1mmx1mm scintillator at the depth of 10cm for the field sizes from the smallest 0.6cm x 1cm to the maximum 40cm x 2cm.Results: For the PDDs of reference field size of 10cm x 2cm measured at Stanford, the maximum doses (dmax) were 12.5mm within the manufacturer's reference range of 13 ± 0.75 mm. The percentage doses at 10cm depth (d10) at reference field size were 56.9% and 57.6% for Stanford and RefleXion measurements, respectively. The longitudinal field sizes for all tested fields were agreed within 0.5mm and the transverse off-axis ratio is within 1% in the beam core (80% of nominal field size). The output factors measured at our institute were ranging from 0.706 to 1.012 relative to the reference 10cm x 2cm field.Conclusion: This evaluation represents the first commissioning evaluation of the dosimetric characteristics of the BgRT system with architecture designed to accommodate both PET detector and LINAC subsystems. This data will serve as a clinical reference for the BgRT treatment planning system's beam model and can act as a standard for comparison and beam model improvement for units installed at future clinical sites. [ABSTRACT FROM AUTHOR]

An electrostatic diesel particulate matter filtration system (EDPS) has been tested using 3000 cc diesel engines operating at steady state and standard (European Stationary Cycle (ESC) 13 mode) conditions. The system consisted of a flowthrough filter (FTF) and a charging device with a round perforated plate imposing an electrostatic field onto the FTF. An insulating device for the high-voltage electrode was protected from pollutant deposition by using an air slit at velocity of 7 m/s to maintain a stable corona discharge under an exhaust temperature exceeding 300°C. Under steady-state engine conditions, the performance test of the EDPS showed high collection performance (based on the particulate matter (PM) number) of nearly 80-99%, while the efficiency of the FTF remained at 15-50%. Comparing the performance of the EDPS with a commercialised diesel particulate filter (DPF) and an FTF under the ESC 13 mode, the EDPS was almost 40% more efficient than the FTF and 10% less efficient than the DPF, while achieving 73% lower pressure drop than the DPF. Thus, the novel filtration system can achieve collection performance similar to the DPF with significantly less pressure drop. [ABSTRACT FROM AUTHOR]

Transcription activator-like effector nucleases (TALENs) enable genome engineering in cell culture and many organisms. Recently, the GoldyTALEN scaffold was shown to readily introduce mutations in zebrafish (Danio rerio) and livestock through non-homologous end joining (NHEJ) and homology-directed repair (HDR). To deploy the GoldyTALEN system for high-throughput mutagenesis in model organisms, a simple design with high efficacy is desirable. We tested the in vivo efficacy of a simplified 15-RVD GoldyTALEN design (spacer between 13–20 bp and T nucleotide preceding each TALEN binding site) in zebrafish. All 14 tested TALEN pairs (100%) introduced small insertions and deletions at somatic efficacy ranging from 24 to 86%, and mutations were inheritable at high frequencies (18–100%). By co-injecting two GoldyTALEN pairs, inheritable deletions of a large genomic fragment up to 18 kb were successfully introduced at two different loci. In conclusion, these high efficiency 15-RVD GoldyTALENs are useful for high-throughput mutagenesis in diverse application including hypothesis testing from basic science to precision medicine. [ABSTRACT FROM AUTHOR]

The most important factor in gas strut design is determining an optimized layout. If the layout is not optimized, vehicle operators will have a suboptimal experience when opening and closing the tailgate. A poor layout of the gas struts causes operators to work excessively when they open/close the tailgate, and vehicle owners will incur additional expenses due to deterioration in the body quality of the vehicle. Thus, an optimized gas strut layout is very important, even if it does not seem interesting. This paper describes the tailgate operation process and focuses on determining an optimized gas strut layout for opening/closing the tailgate easily. [ABSTRACT FROM AUTHOR]

The versatility of nanodiamonds (NDs) as a polymer-embedded therapeutic vehicle was demonstrated by the development of a hybrid material consisting of a poly(ethylene glycol) diacrylate (PEGDA) hydrogel embedded with ND-drug complexes. A wide range of PEGDA structures, including single and multiple drug reservoirs, exhibited high loading capabilities and stable slow-release, augmented with the addition of ND conjugates. ND-PEGDA hydrogels were compared to unmodified, drug-embedded PEGDA hydrogels to demonstrate their robust drug sequestering capacity in vitro. Remarkably, ND-embedded hydrogels were capable of mitigating the harmful effects of burst-release by displaying slow and controlled administration of therapeutic compounds, an improvement over standard diffusion-based release profiles. The tunable customization of PEGDA hydrogel, both in structure and content, as well as its facile methods of synthesis, make this material an effective multi-therapeutic complement to the drug delivery abilities of NDs. A hybrid material that utilizes the synergy of PEGDA and ND components has the potential for applications toward a diverse array of biomedical challenges. [ABSTRACT FROM AUTHOR]

A spectrum of materials has been explored as potential platforms for nanomedicine in the areas of drug delivery, imaging, and diagnostics/sensing. Depending upon the application required, the therapeutic compound being delivered, or the imaging agent being modified, certain nanoparticulate materials offer specific advantages that may uniquely enhance efficiency. Among the classes of particles being investigated, diamond-based platforms have emerged as promising vehicles for drug delivery and imaging following several recent studies that demonstrate their ability to enhance therapeutic efficacy, particularly for anthracyclines, mediate markedly improved magnetic resonance imaging contrast and photostable fluorescence, possess scalable processing parameters, and exhibit biocompatibility, among many other important attributes. More specifically, detonation NDs have faceted surfaces that can mediate potent interactions with surrounding water molecules or therapeutic compounds. This attribute can mitigate premature drug release to prevent major side effects such as myelosuppression, while water molecule recruitment can increase the relaxivity of covalently conjugated gadolinium. These properties of NDs and diamond-based devices will be discussed in this article, with a focus on therapeutic delivery in addition to insight on their use in imaging, devices, implants/coatings, and biocompatibility. Key areas of potential, where advances in biology and medicine can be realized through the continued development of this platform as well as requisite future studies, will also be highlighted. [ABSTRACT FROM AUTHOR]

Image registration is a fundamental task in computer vision and it significantly contributes to high-level computer vision and benefits numerous practical applications. Although many image registration techniques have been proposed in the past, there is still a need for further research because many issues such as the parallax problem remain to be solved. The traditional image registration algorithms suffer from the parallax problem due to their underlying assumption that the scene can be regarded approximately planar which is not satisfied when large depth variations exist in the images with high-rise objects. To address the parallax problem, we present a new strategy for two-dimensional (2D) image registration by leveraging the depth information from a 3D image reconstruction. The novel idea is to recover the depth in the image region with high-rise objects to build an accurate transform function for image registration. We use a geometric segmentation algorithm to partition 3D point cloud to multiple geometric structures and at the same time, estimate the parameters of each geometric structure. Experimental results show that the proposed method is able to mitigate the parallax problem and achieve better performance than the existing image registration scheme. [ABSTRACT FROM AUTHOR]