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Purpose Central venous catheter (CVC)-related thrombosis (CRT) is a known complication in critically ill patients. However, its clinical significance remains unclear. The objective of the study was to evaluate the occurrence and evolution of CRT from CVC insertion to removal. Methods A prospective multicenter study was conducted in 28 intensive care units (ICUs). Duplex ultrasound was performed daily from CVC insertion until at least 3 days after CVC removal or before patient discharge from the ICU to detect CRT and to follow its progression. CRT diameter and length were measured and diameter > 7 mm was considered extensive. Results The study included 1262 patients. The incidence of CRT was 16.9% (95% confidence interval 14.8-18.9%). CRT was most commonly found in the internal jugular vein. The median time from CVC insertion to CRT onset was 4 (2-7) days, and 12% of CRTs occurred on the first day and 82% within 7 days of CVC insertion. CRT diameters > 5 mm and > 7 mm were found in 48% and 30% of thromboses. Over a 7-day follow-up, CRT diameter remained stable when the CVC was in place, whereas it gradually decreased after CVC removal. The ICU length of stay was longer in patients with CRT than in those without CRT, and the mortality was not different. Conclusion CRT is a frequent complication. It can occur as soon as the CVC is placed and mostly during the first week following catheterization. Half of the thromboses are small but one-third are extensive. They are often non-progressive and may be resolved after CVC removal., Author(s): Chunshuang Wu [sup.1] [sup.2] [sup.3], Mao Zhang [sup.1] [sup.2] [sup.3], Wenjie Gu [sup.1] [sup.2] [sup.3], Caimu Wang [sup.4], Xudong Zheng [sup.5], Junfeng Zhang [sup.6], Xingwen Zhang [sup.7], Shijin Lv [...]

To investigate the effects of silicon formulations on the cold tolerance of rice seedlings, Song Japonica 16 (not cold tolerant) and Dongnong 427 (cold tolerant) rice varieties were used as test materials and four different types of silicon formulations, Si-50-G, Si-60-G, Si-T-G, and Si-E-G, were applied as foliar sprays at the seedling stage, and a control group CK (equal amount of distilled water) was set up. One week after the first silicon spray, two types of rice were subjected to low-temperature stress treatments at day/night temperatures of 12 °C/10 °C for 2, 4, 6, and 8 days. The effects of different silicon formulations on the chlorophyll, proline (Pro) and soluble sugar contents as well as superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities of rice seedlings under low-temperature stress were compared to find out the effects of silicon formulations on the cold tolerance of rice seedlings. The results showed that silicon formulations could significantly increase the chlorophyll content of rice seedling leaves, with Si-50-G being the most effective, with a significant increment of 40.17% compared to the CK at 2 days of low temperature. Four silicon formulations significantly increased the proline content and soluble sugar content of rice leaves at low temperature for 4-8 days. For Song Japonica 16, the most significant increment in leaf POD activity was observed in Si-E-G treatment at 2, 4 and 8 days of temperature stress, with 73.58%, 20.95% and 217.24% increases compared to the CK, respectively. For 4 and 6 days of temperature stress, the most significant increase in CAT activity was observed in Si-E-G treatment, with 25.70% and 75.78% increases compared to the CK, respectively. For Dongnong 427, the Si-60-G treatment showed the highest increase in leaf SOD activity for 4 and 8 days of temperature stress, with significant increases of 58.15% and 82.76% compared to the CK, respectively, and the Si-E-G treatment showed the highest increase in leaf POD activity for 2 and 8 days of temperature stress, with significant increases of 97.75% and 245.10% compared to the CK, respectively. It showed that the spraying of silicon formulations could significantly enhance the cold tolerance of rice. This study provided a scientific basis for the rational use of silicon formulations to enhance cold tolerance in rice and had important theoretical and practical significance for ensuring sustainable high and stable rice yields in Heilongjiang Province, as well as for the development of silicon fertilizers. [ABSTRACT FROM AUTHOR]

This study was to explore the functional mechanism of rare earth regulating soybean leaves and the characteristics and functions of differentially expressed proteins under the regulation of rare earth. In this study, Dongnong 42 was used as material, and 30 mg ⋅ L-1 CeCl3 solution was sprayed on soybean leaves at the seedling stage. Tandem mass tag (TMT) quantitative proteomics technique and bioinformatics analysis were used to identify soybean leaf proteins. A total of 8 510 proteins were identified, and 127 differentially expressed proteins (DEPs) in response to rare earth cerium regulation were identified, among which 64 were upregulated and 63 were down-regulated. The gene ontology (GO) annotation indicated that DEPs were mainly involved in metabolic process, cellular process, response to stimulus, biological regulation, and response to a stimulus; DEPs in cell module categories were mainly involved in cells, cell part, organelle, membrane, membrane part, organelle par, and protein-containing complex; DEPs in molecular functional categories were mainly involved in catalytic activity, binding and antioxidant activity. Kyoto encyclopedia of genes and genomes (KEGG) pathway significantly enriched starch and sucrose metabolism, glycolysis/gluconeogenesis, galactose metabolism, pentose phosphate pathway, and MAPK signaling pathway-plant. These DEPs were mainly involved in photosynthesis, glucose metabolism and stress response. Forty-six differential protein interaction networks were identified by protein interaction network analysis. This experiment provided a reference for studies of the mechanism of rare earth cerium regulating soybean leaf function from the proteomic perspective. [ABSTRACT FROM AUTHOR]

In order to optimize the additive manufacturing process and find the process parameters affecting the mechanical properties of the parts, an additive manufacturing simulation model of Ti-6Al-4V titanium alloy was established, and the effects of ambient temperature, substrate thickness and wire temperature on the stress field and residual stress field were analyzed. The results show that the ambient temperature is inversely proportional to the residual stress of the cladding layer, while the substrate thickness and wire temperature are positively correlated to the residual stress of the cladding layer. When the ambient temperature increases from 0 °C to 600 °C, the maximum residual stress decreases by 36.0%, the maximum residual stress increases by 10.0% when the substrate thickness increases from 25 mm to 55 mm and the maximum residual stress increases by 7.48% when the temperature increases from 0 °C to 600 °C. The influence of the three parameters on the maximum residual stress is as follows: ambient temperature > substrate thickness > wire temperature. The research results can provide reference for stress control during actual manufacturing. [ABSTRACT FROM AUTHOR]

aimed to provide feasible suggestions for intraventricular injection of tigecycline to treat intractable Acinetobacter baumannii intracranial infections by studying its pharmacokinetics/pharmacodynamics and neurotoxicity. Methods: A simple and reliable two-dimensional high-performance liquid chromatography (2D-HPLC) method was used to determine tigecycline concentration. The pharmacokinetics (PK) of tigecycline in cerebrospinal fluid (CSF) was investigated by performing therapeutic drug monitoring (TDM). The pharmacodynamics (PD) of tigecycline was evaluated by its minimum inhibitory concentration (MIC) against XDR A. baumannii. CCK8 assay was used to evaluate the cytotoxicity of different concentrations of tigecycline effect on PC12 cells, and apoptosis assay was analyzed by flow cytometry. Results: Tigecycline retention time in 2D-HPLC was 7.636 min. The lower limit of quantitation (LLOQ) was 0.1mg/L, which met the requirements of concentration determination for TDM. The MIC50 and MIC90 values of tigecycline for A. baumannii were 2 and 4 mg/L, respectively. After a dose of 5mg tigecycline, Cmax in CSF was 37.894 mg/L which was high above the MIC values. The t1/2 of tigecycline was estimated to be 2.73 hours. Tigecycline significantly decreased cell viability as assessed and induced apoptosis of the PC12 cell. The IC50 value of PC12 cells treated with tigecycline was about 51.35 mg/L. Conclusion: Intraventricular injection of tigecycline is a promising method for treating XDR A. baumannii intracranial infection. Since a high concentration of tigecycline in CSF may have potential neurotoxicity, and the t1/2 was short, giving small doses of less than 5 mg at least twice a day may be safer and more effective. Intraventricular injection of tigecycline must be selected cautiously and best carried out under TDM. [ABSTRACT FROM AUTHOR]

The vehicle routing problem with time windows (VRPTW) is an important problem in logistics. The problem is to serve a number of customers at minimum cost without violating the customers' […]

The effects of different Ce content on the microstructure and corrosion resistance of Al-5Mg-3Zn-1Cu alloy in metal mold gravity casting were studied in this paper. The microstructure of the alloy was characterized by scanning electron microscope (SEM) and X-Ray diffractometer (XRD). The corrosivity of all alloys in 3.5 wt.%NaCl solution was studied by electrochemical and immersion corrosion techniques. The results show that the microstructure of the alloy is mainly composed of α-Al, T phase, and Al2Cu phase. Ce can refine the organization of the alloy, but when the addition of Ce is higher than 0.25 wt.%, a massive Ce-rich phase appears in the alloy. The results of a potential polarization test show that the corrosion potential of the alloy increases obviously from −1.253 V to −1.193 V with the increase in Ce content in the alloy. [ABSTRACT FROM AUTHOR]

Three decades of research have demonstrated that biodiversity can promote the functioning of ecosystems. Yet, it is unclear whether the positive effects of biodiversity on ecosystem functioning will persist under various types of global environmental change drivers. We conducted a meta‐analysis of 46 factorial experiments manipulating both species richness and the environment to test how global change drivers (i.e. warming, drought, nutrient addition or CO2 enrichment) modulated the effect of biodiversity on multiple ecosystem functions across three taxonomic groups (microbes, phytoplankton and plants). We found that biodiversity increased ecosystem functioning in both ambient and manipulated environments, but often not to the same degree. In particular, biodiversity effects on ecosystem functioning were larger in stressful environments induced by global change drivers, indicating that high‐diversity communities were more resistant to environmental change. Using a subset of studies, we also found that the positive effects of biodiversity were mainly driven by interspecific complementarity and that these effects increased over time in both ambient and manipulated environments. Our findings support biodiversity conservation as a key strategy for sustainable ecosystem management in the face of global environmental change. [ABSTRACT FROM AUTHOR]

This study aimed to analyze the defects of large residual stress in laser additive manufacturing metal parts by establishing a milling numerical simulation of Ti6Al4V titanium alloy thin-walled parts based on the Johnson-Cook constitutive model of Ti6Al4V titanium alloy, a modified Coulomb friction stress model, the physical chip separation criterion and other theories, combined with the finite element software ABAQUS. The influences of milling depth, initial temperature and milling speed on the forming quality of the formed part were analyzed. The results show that milling changes the residual stress distribution of the deposition layer, which can reduce or even change the residual tensile stress on the surface of the deposition layer produced by the additive manufacturing process into compressive stress, and the equivalent Mises stress decreases by 47% compared with the original forming surface. When the initial temperature increases from 20 °C to 400 °C, the maximum equivalent Mises stress of the milling surface decreases by 26%. [ABSTRACT FROM AUTHOR]

An ultra-wideband mixing component cascaded by a mixing multi-function chip and a frequency multiplier multi-function chip was demonstrated and implemented using 3D heterogeneous integration based on the silicon adapter board technology. Four layers of high-resistance silicon substrate stack packaging are implemented based on the wafer-level gold-gold bonding process. Each layer adopts tough silicon via (TSV) technology to realize signed interconnection. A core monolithic integrated microwave chip (MMIC) is embedded in the silicon cavity, and the silicon-based filter is integrated with the high-resistance silicon substrate. The interconnect line, cavity and filter of the silicon-based adapter board are designed with AutoCAD, and HFSS is adopted for 3D electromagnetic field simulation. According to the measured results, the radio frequency (RF) of the mixing multi-function chip is 40-44 GHz and its intermediate frequency (IF) can cover the Ku band with a chip size of 10 mm x 11 mm x 1 mm. Tie multiplier multi-function chip operates at t6-20 GHz. The fundamental suppression is greater than 50 dB and the second harmonic suppression is better than 40 dB with a chip size of 8 mm x 8 mm x 1 mm. The cascaded fully assembled mixing component achieves a spur of better than -50 dBc and a gan of better than 15 dB. [ABSTRACT FROM AUTHOR]

Malware brings a big security threat on the Internet today. With the great increasing malware attacks. Behavior-based detection approaches are one of the major method to detect zero-day malware. Such approaches often use API calls to represent the behavior of malware. Unfortunately, behavior-based approaches suffer from behavior obfuscation attacks. In this paper, we propose a novel malware detection approach that is both effective and efficient. First, we abstract the API call to object operation. And then we generate the object operation dependency graph based on these object operations. Finally, we construct the family dependency graph for a malware family. Our approach use family dependency graph to represent the behavior of malware family. The evaluation results show that our approach can provide a complete resistance to all types of behavior obfuscation attacks, and outperforms existing behavior-based approaches in terms of better effectiveness and efficiency. [ABSTRACT FROM AUTHOR]

A uniform nanocoating can substantially enhance the electrochemical properties of cathode materials. Herein, we report that a uniform AlPO4 coating can be produced on the surface of LiNi0.8Co0.15Al0.05O2 (NCA) particles by a homogeneous precipitation method, which was confirmed by scanning electron microscopy and energy dispersive x-ray spectroscopy. After being heated, the AlPO4 was converted to the Li3PO4 which was verified by x-ray diffraction. The heated AlPO4 coated NCA demonstrated a substantially enhanced electrochemical performance. The capacity retention increased from 87.38% for bare NCA to 94.28% for the heated 1 wt.% AlPO4 coated NCA sample. Moreover, the reversible capacity at 5 C increased from 80 mAh/g for bare NCA to 120 mAh/g for the heated 1 wt.% AlPO4-coated NCA. In addition, improved thermal stability was also found. The start temperature of thermal runaway increased from 175.12°C for bare NCA to 200.32°C for the heated 1 wt.% AlPO4-coated NCA. [ABSTRACT FROM AUTHOR]

Traditional electrophilic bromination follows long established “rules”: electron-withdrawing substituents cause bromination selective for meta positions, whereas electron-donating substituents favor ortho and para bromination. In contrast, in the [PhSiO1.5]8,10,12 silsesquioxanes, the cages act as bulky, electron withdrawing groups equivalent to CF3; yet bromination under mild conditions, without a catalyst, greatly favors ortho substitution. Surprisingly, ICl iodination without a catalyst favors (＞90%) para substitution [p-IC6H4SiO1.5]8,10,12. Finally, nitration and Friedel–Crafts acylation and sulfonylation are highly meta selective, ＞80%. In principle, the two halogenation formats coupled with the traditional electrophilic reactions provide selective functionalization at each position on the aromatic ring. Furthermore, halogenation serves as a starting point for the synthesis of two structural isomers of practical utility, i.e. in drug prospecting. The o-bromo and p-iodo compounds are easily modified by catalytic cross-coupling to append diverse functional groups. Thereafter, F−/H2O2 treatment cleaves the Si–C bonds replacing Si with OH. This represents a rare opportunity to introduce hydroxyl groups to aromatic rings, a process not easily accomplished using traditional organic synthesis methods. The as-produced phenol provides additional opportunities for modification. Each cage can be considered a nanoreactor generating 8–12 product molecules. Examples given include syntheses of 4,2′-R,OH-stilbenes and 4,4′-R,OH-stilbenes (R = Me, CN). Unoptimized cleavage of the Br/I derivatives yields 55–85% phenol. Unoptimized cleavage of the stilbene derivatives yields 35–40% (3–5 equivalents of phenol) in the preliminary studies presented here. In contrast, meta R-phenol yields are 80% (7–10 mol per cage). [ABSTRACT FROM AUTHOR]

In this work, the flow features of coaxial rotors measured in water tunnel are investigated via particle image velocimetry technique. The experiments are conducted using a two-bladed model-scale coaxial rotor and a single rotor with the same geometry. Some noticeable flow features are found. For the coaxial rotor in hover, there is an annular region radially inboard of the lower rotor disk, where there are almost no intrusions from the upper rotor wake. At the same time, upwash occurs at the outboard edge of the lower rotor, while no such phenomenon occurs near the upper rotor blade tip. Sometimes, two upwash phenomena are found both at the blade tip and root in the single-rotor case. For both the single and coaxial rotors in forward flight, there is a sudden velocity change at about 0.7 R on the retreating side. From comparisons with the prior performance experiments, it can also be found that mutual interferences are playing a positive role in the hovering coaxial rotor configuration. The previously prescribed wake models can well describe the tip vortex trajectories of the single rotor and coaxial rotor in hover and forward flight, especially at high advance ratios. However, in this experiment, some special features are also found slightly different with that of the experiment conducted in air. Some valuable results obtained from this experiment would be helpful to reasonable designs of coaxial helicopters in the future. [ABSTRACT FROM AUTHOR]

The direct depolymerization of SiO2 to distillable alkoxysilanes has been explored repeatedly without success for 85 years as an alternative to carbothermal reduction (1900 °C) to Simet, followed by treatment with ROH. We report herein the base-catalyzed depolymerization of SiO2 with diols to form distillable spirocyclic alkoxysilanes and Si(OEt)4. Thus, 2-methyl-2,4-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, or ethylene glycol (EGH2) react with silica sources, such as rice hull ash, in the presence of NaOH (10 %) to form H2O and distillable spirocyclic alkoxysilanes [bis(2-methyl-2,4-pentanediolato) silicate, bis(2,2,4-trimethyl-1,3-pentanediolato) silicate or Si(eg)2 polymer with 5-98 % conversion, as governed by surface area/crystallinity. Si(eg)2 or bis(2-methyl-2,4-pentanediolato) silicate reacted with EtOH and catalytic acid to give Si(OEt)4 in 60 % yield, thus providing inexpensive routes to high-purity precipitated or fumed silica and compounds with single Si−C bonds. [ABSTRACT FROM AUTHOR]

Owing to the effect of atomic vibrations, a high-temperature phase usually features a relatively smaller density when compared with a low-temperature phase. In this work, a new SrCdB2O5 phase has been discovered. According to the crystallization temperature from low to high, the new SrCdB2O5 phase can be regarded as the high-temperature β-SrCdB2O5 phase. The density of β-SrCdB2O5 is obviously larger than that of α-SrCdB2O5, meanwhile β-SrCdB2O5 is energetically favored. This unusual density evolution phenomenon has been investigated. In addition, the Pb2+-doped compounds, PbxSr1−xCdB2O5 (x = 0.125, 0.25, 0.375, 0.5), have also been investigated by powder refinement. [ABSTRACT FROM AUTHOR]

Two new borate halides, Pb6Ba2(BO3)5X (X = Cl, Br), have been synthesized by solid-state reactions and their structures determined by single-crystal X-ray diffraction. They are isostructural and feature 3D frameworks composed of alternate stacking of [PbBO] and [PbBOX] layers which are connected by 10-coordinated Ba atoms along the c direction. First-principles calculations show that both compounds have a large birefringence of 0.1582 and 0.1810 at 532 nm, respectively. The large birefringence originates from the strong optical anisotropies of the Pb2+ cations and (BO3)3− groups based on the real-space atom-cutting analysis. The IR and UV–Vis–NIR diffuse reflectance spectroscopy, as well as thermal stability analyses of both compounds, were performed. [ABSTRACT FROM AUTHOR]

Motor neuron hyperexcitability (MNH) indicates a disorder characterized by an ectopic motor nerve discharge on electromyogram (EMG). Here, we present a series of three cases of subacute MNH with mercury poisoning. The first case showed hyperhidrosis, insomnia, generalied myokymia, cramps, tremor, weight loss, and myokymic and neuromyotonic discharges, followed by encephalopathy with confusion, hallucinations, and memory decrease. The second case was similar to the former but without encephalopathic features. The third case showed widespread fasciculation, fatigue, insomnia, weight loss, and autonomic dysfunction, including constipation, micturition difficulty, and impotence, with multiple fibrillation, unstable fasciculation, widened motor neuron potential, and an incremental response at high-rate stimulation in repetitive nerve stimulation. Based on the symptoms, the three cases were diagnosed as Morvan's syndrome, Isaacs' syndrome, and Lambert-Eaton myasthenic syndrome with ALS-like syndrome, respectively. Mercury poisoning in the three cases was confirmed by analysis of blood and urine samples. All cases recovered several months after chelation therapy and were in good condition at follow-up. Very few cases of MNH linked with mercury exposure have been reported in the literature. The mechanism of mercury-induced MNH may be associated with ion channel dysfunction. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]