The critical behavior of square well fluids with variable interaction ranges and of short square well chain fluids have been investigated by grand canonical ensemble Monte Carlo simulations. The critical temperatures and densities were estimated by a finite-size scaling analysis with the help of histogram reweighting technique. The vapor-liquid coexistence curve in the near-critical region was determined using hyper-parallel tempering Monte Carlo simulations. The simulation results for coexistence diameters show that the contribution of |t|(1-?) to the coexistence diameter dominates the singular behavior in all systems investigated. The contribution of |t|(2?) to the coexistence diameter is larger for the system with a smaller interaction range ?. While for short square well chain fluids, longer the chain length, larger the contribution of |t|(2?). The molecular configuration greatly influences the critical asymmetry: a short soft chain fluid shows weaker critical asymmetry than a stiff chain fluid with same chain length.
TiO? nanoparticle layers composed of columnar TiO? nanoparticle piles separated with nanoscale pores were fabricated on the bottom surface of the hemispherical glass prism by performing gas phase cluster beam deposition at glancing incidence. The porosity as well as the refractive index of the nanoparticle layer was precisely tuned by the incident angle. Effective extraction of the light trapped in the substrate due to total internal reflection with the TiO? nanoparticle layers was demonstrated and the extraction efficiency was found to increase with the porosity. An enhanced Rayleigh scattering mechanism, which results from the columnar aggregation of the nanoparticles as well as the strong contrast in the refractive index between pores and TiO? nanoparticles in the nanoporous structures, was proposed. The porous TiO? nanoparticle coatings were fabricated on the surface of GaN LEDs to enhance their light output. A nearly 92% PL enhancement as well as a 30% EL enhancement was observed. For LED applications, the enhanced light extraction with the TiO? nanoparticle porous layers can be a supplement to the microscale texturing process for light extraction enhancement.
Acute lung injury may lead to fibrogenesis. However, no treatment is currently available. This study was conducted to determine the effects of bone marrow-derived mesenchymal stem cells (MSCs) in a model of HCl-induced acute lung injury in Sprague-Dawley (SD) rats. Stromal cell-derived factor (SDF)-1 and its receptor CXC chemokine receptor (CXCR)4 have been shown to participate in mobilizing MSCs. Adenovirus carrying the CXCR4 gene was used to transfect MSCs in order to increase the engraftment numbers of MSCs at injured sites. Histological examination data demonstrated that the engraftment of MSCs did not attenuate lung injury and pulmonary fibrosis. The results showed that engraftment of MSCs almost differentiated into myofibroblasts, but rarely differentiated into lung epithelial cells. Additionally, it was demonstrated that activated canonical Wnt/?-catenin signaling in injured lung tissue regulated the myofibroblast differentiation of MSCs in vivo. The in vitro study results demonstrated that activation of the Wnt/?-catenin signaling stimulated MSCs to express myofibroblast markers; however, this process was attenuated by Wnt antagonist DKK1. Therefore, the results demonstrated that the aberrant activation of Wnt signaling induces the myofibroblast differentiation of engrafted MSCs, thus contributing to pulmonary fibrosis following lung injury.
Hydrogen is one of the most important industrial chemicals and will be arguably the best fuel in the future. Hydrogen production from less costly renewable sugars can provide affordable hydrogen, decrease reliance on fossil fuels, and achieve nearly zero net greenhouse gas emissions, but current chemical and biological means suffer from low hydrogen yields and/or severe reaction conditions. An in vitro synthetic enzymatic pathway comprised of 15 enzymes was designed to split water powered by sucrose to hydrogen. Hydrogen and carbon dioxide were spontaneously generated from sucrose or glucose and water mediated by enzyme cocktails containing up to 15 enzymes under mild reaction conditions (i.e. 37°C and atm). In a batch reaction, the hydrogen yield was 23.2mol of dihydrogen per mole of sucrose, i.e., 96.7% of the theoretical yield (i.e., 12 dihydrogen per hexose). In a fed-batch reaction, increasing substrate concentration led to 3.3-fold enhancement in reaction rate to 9.74mmol of H2/L/h. These proof-of-concept results suggest that catabolic water splitting powered by sugars catalyzed by enzyme cocktails could be an appealing green hydrogen production approach.
High-energy-density, green, safe batteries are highly desirable for meeting the rapidly growing needs of portable electronics. The incomplete oxidation of sugars mediated by one or a few enzymes in enzymatic fuel cells suffers from low energy densities and slow reaction rates. Here we show that nearly 24 electrons per glucose unit of maltodextrin can be produced through a synthetic catabolic pathway that comprises 13 enzymes in an air-breathing enzymatic fuel cell. This enzymatic fuel cell is based on non-immobilized enzymes that exhibit a maximum power output of 0.8?mW?cm(-2) and a maximum current density of 6?mA?cm(-2), which are far higher than the values for systems based on immobilized enzymes. Enzymatic fuel cells containing a 15% (wt/v) maltodextrin solution have an energy-storage density of 596?Ah?kg(-1), which is one order of magnitude higher than that of lithium-ion batteries. Sugar-powered biobatteries could serve as next-generation green power sources, particularly for portable electronics.
Guided bone regeneration (GBR) is a new method of promoting new bone formation by blocking the proliferation of regenerated connective tissue or providing additional interventions such as direct drug delivery and mechanical support. This in vivo study of bone regeneration in radius compound fractures in rabbits was conducted using a highly flexible scaffold of nanoscale hydroxyapatite (nHAp)/chitosan, termed a "bone patch". A solidification-assisted compression (SAC) method was utilized to fabricate the bone patch, and its in vivo cytotoxicity, bio-absorption, and bone regeneration capacity were evaluated. Four weeks after implantation, new bone formation with abundant active osteoblasts and incompleted degradation of chitosan in the patch were observed without any regeneration of connective tissue, compared with the corresponding implant without a patch. X-ray images showed that the radius with the bone patch had higher opacity than that of the control, which was consistent with the results obtained via histological analysis. Evidently, the nHAp-embedded bone-patch scaffold has considerable potential for application in the field of orthopedics of bone regeneration.
Although individuals with posttraumatic stress disorder (PTSD) are at heightened risk for several serious health conditions, research has not examined how having PTSD impacts receipt of invasive procedures that may alleviate these problems. We examined whether PTSD, after controlling for major depression, was associated with odds of receiving common types of major invasive procedures, and whether race, ethnicity, and gender was associated with odds of procedures.
The 70% alcohol extract of Oxytropis myriophylla (PALL.) DC. (Leguminosae) exhibited high radical scavenging activity (IC(50) value: 88.0?µg?mL(-1) and 86.7?µg?mL(-1)) on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. Further chemical investigation led the isolation of one new lignan, namely myriophylloside G (1), together with three known compounds. Their structural elucidations of all the compounds were based on extensive spectroscopic methods, including HRESIMS and 2D NMR experiments (HSQC, HMBC and (1)H-(1)HCOSY) and by comparison with reference values.
Acute fever is the most common early clinical symptom of many critical illnesses with a high mortality rate. It is necessary to identify patients with severe acute fever early and accurately. The aim of this study is to identify risk factors for critically ill outpatients with acute fever and formulate activation criteria of adult fever state score (AFSS) to alert outpatient clinic doctors.
Tissue engineering utilizes expertise in the fields of materials science, biology, chemistry, transplantation medicine, and engineering to design materials that can temporarily serve in a structural and/or functional capacity during regeneration of a defect. Hydroxyapatite (HAp) scaffolds are among the most extensively studied materials for this application. However, HAp has been reported to be too weak to treat such defects and, therefore, has been limited to non-load-bearing applications. To capitalize the advantages of HAp and at the same time overcome the drawbacks nanocrystalline HAp (nHAp) is combined with various types of bioactive polymers to generate highly porous biocomposite materials that are used for osteoconduction in the field of orthopedic surgery. In this study we have reviewed nanosized HAp-based highly porous composite materials used for bone tissue engineering, introduced various fabrication methods to prepare nHAp/polymer composite scaffolds, and characterized these scaffolds on the basis of their biodegradability and biocompatibility through in vitro and in vivo tests. Finally, we provide a summary and our own perspectives on this active area of research.
Three new flavonoids, myriophylloside I, II and III, were isolated from Oxytropis myriophylla (Leguminosae), together with four known flavonoid glycosides: isorhamnetin-3-O-?-D-glucoside, isorhamnetin-3-O-?-L-arabinosyl(1?6)-?-D-glucoside, quercetin and rutin. The structural elucidations of all the compounds were based on extensive spectroscopic methods, including HRESIMS and 2D-NMR experiments (HSQC, HMBC, (1)H-(1)H COSY and HSQC-TOCSY), UV, IR and chemical evidence, together with comparison with reference values.
Emissions from industrial activities pose a serious threat to human health and impose the need for monitoring both inorganic and organic pollutants in industrial areas. We selected Masson pine (Pinus massoniana L.) as potential biomonitor and collected the current (C) and previous year (C+1) needles from three industrial sites dominated by petrochemical, ceramics manufacturing, and iron and steel smelting plants and one remote site to determine heavy metals (Cu, Cd, Pb, Zn, Cr, Ni and Co) and polycyclic aromatic hydrocarbons (PAHs) in unwashed and water-washed needles. Both unwashed and washed C+1 needles showed generally higher concentrations of heavy metals and PAHs than C needles, although the washed needles more clearly spotlighted the accumulation effect of PAHs over exposure time. Water-washing resulted in a significant decrease in needle PAH concentrations with more significant effects shown in C needles. By contrast, needle heavy metal concentrations were much less affected by washing. Although heavy metals and PAHs might differ in adsorption and uptake strategies, their higher concentrations in the needles at the industrial sites indicated conspicuous contamination due to industrial emissions there. The PAH distribution patterns in pine needles accorded with the real types of energy consumption in the study sites and were efficiently used for pinpointing local pollutant sources.
Acute fever is the most common clinical symptom for infectious diseases. It is necessary to identify risk factors for infectious patients with acute fever and formulate activation criteria of early warning infectiosity score system (EWIS) to alert outpatient clinic doctors.
Semiconductor nanomaterials have attracted considerable attention in the design of high efficiency PL up-conversion in heterojunctions or nanostructures at extremely low continuous wave (cw)-excitation intensity. In this study, bioconjugated hybrids were constructed using CdTe and Au nanoparticles (NPs), where two-fold PL enhancement was observed in the solution state. These results are in accordance with theoretical predictions of the local-field effects associated with the combined influence of strong localization of the collective plasmon modes in metallic-semiconducting hybrids and multi-photon absorption into its localized plasmon modes. The feasibility of the nanohybrids as sensors was demonstrated by breaking the bioconjugation through thermal stress, which induced a rapid decrease in luminescence intensity. It is believed that the phenomena is applicable to high-compacted optoelectronic devices and sensing systems that take advantage of both quantum confinement effects and nonlinear optical properties.
Hydroxyapatite (HAp) was coated on scratched areas of a human tooth and HAp disks by the immersion method in a HAp colloidal solution (< or =20 microm of average diameter dispersed in DI water). The surface morphologies of the scratched area after immersion for 1-3 months were investigated showing that the damaged surfaces were remarkably recovered. Then, the mechanical property and chemical stability of the HAp coating layers on both specimens were determined via the Vickers hardness test and concentration measurement of extracted Ca2+ ions, respectively, after strong acidic treatment. The cellular behavior of mouse calvaria-derived pre-osteoblastic cells (MC3T3-E1) was also examined on the HAp layers regenerated on micro-scratched HAp disks for the purpose of their potential applications on maxillofacial bone conservation and reconstruction for prosthetic dentistry, and artificial disk preparation of a vertebral column. The notable loss of Ca2+ ions under a highly acidic condition was not observed in the layers coated by HAp adsorption, indicating that the coating surface was well adhered with the original surfaces of the respective specimen. Moreover, the HAp adsorption did not adversely affect the adhesion, growth and proliferation of MC3T3-E1 cells on the coated HAp layers for up to 21 days. These results suggest that the HAp coating on the scratched areas of the tooth would be effectively applicable for the development of long-term prevention of micro-cleavage and tooth health supporters to reduce discoloration and further maxillofacial and orthopedic applications.
Angiotensin-converting enzyme 2 (ACE2), its product angiotensin-(1-7) and its receptor Mas may counteract the adverse effects of the ACE-angiotensin receptor II-AT(1) axis in many diseases. We examined the expression of these novel components of the rennin-angiotensin system in an experimental mouse model of severe acute pancreatitis (SAP).
The inflorescences as explants for rapid propagation in vitro remained unknown in Populus euphratica Olivier. Here, we reported that multiple shoots were initiation from calli of both male and female inflorescences. The optimum medium for shoot induction from male inflorescences was lactose sulfite medium containing 1.0 mg?L(-1) 6-benzylaminopurine (BA) and 0.5 mg?L(-1) ?-naphthalene acetic acid (NAA) or Murashige and Skoog (MS) medium containing 0.5 mg?L(-1) BA and 0.2 mg?L(-1) NAA. The optimum medium of shoot induction from female inflorescence calli was the MS medium containing 0.5 mg?L(-1) BA and 0.2 mg?L(-1) NAA. Rooting of regenerated shoots was obtained on 1/2 MS medium supplemented with 0.5?1.0 mg?L(-1) indole-3-butyric acid (IBA) and the highest frequency rooting was on medium containing 0.5 mg?L(-1) IBA. No shoots were obtained on medium without BA and NAA. Peroxidase (POD) activity was measured by polyacrylamide gel electrophoresis during shoot induction and differentiation stages. The results showed that two bands of POD (2a and 2b) activity appeared lowest during the early 8 days at the dedifferentiation phase of leaves inducing calli, whereas POD 2a, 2b activity appeared to be increasing at the homeochronous dedifferentiation phase of inflorescence. Five most intensive bands, POD 1a, 1b, 1c, 2a, and ab, appeared in 8th and 28th days at the redifferentiation phase during shoot morphogenesis. These results demonstrated that the POD was involved in shoot morphogenesis from both leaf and inflorescence explants of Populus euphratica.
Despite the high prevalence of posttraumatic stress disorder (PTSD) and medical comorbidity among veterans from Iraq/Afghanistan (OEF/OIF), keeping these patients engaged in health care is challenging. Primary Care-Mental Health Integration (PC-MHI), an initiative in the Veterans Health Administration (VA), sought to improve access to mental health care from within primary care. This study examined the lag between first PC-MHI visit and next mental/medical care visit, if any, and the relationship of PC-MHI with short-term (subsequent year) and long-term (4 years later) use of VA. We identified 2,470 OEF/OIF veterans receiving care during fiscal year 2006 (FY06) in a regional VA health care system. Unconditional survival analysis modeled time to next mental/medical visit and logistic regression modeled short- and long-term care as a function of PC-MHI, demographics, and clinical covariates. Of 181 patients in the PC-MHI program, 60%/18% returned for mental/medical care within 1 month, and 82%/74% within 1 year. Sixty-one percent (1,503) were still using the VA in FY09. Short-term mental care was related to prior-year PC-MHI. Consistent correlates of short- and long-term mental/medical care included physical comorbidity and Priority 1 status. Most patients attended mental health appointments subsequent to PC-MHI, and PC-MHI was correlated with mental health treatment retention in adjusted models for our cohort. Need for treatment, notably VA Priority 1 status and physical comorbidity, were the primary correlates of care-seeking. Developing innovative approaches to engaging new veterans in care remains imperative as multiple options will be necessary to meet the needs of these complex patients.
A synthetic enzymatic pathway was designed for the deep oxidation of glucose in enzymatic fuel cells (EFCs). Polyphosphate glucokinase converts glucose to glucose-6-phosphate using low-cost, stable polyphosphate rather than costly ATP. Two NAD-dependent dehydrogenases (glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase) that were immobilized on the bioanode were responsible for generating two NADH per glucose-6-phosphate (i.e., four electrons were generated per glucose via a diaphorase-vitamin K(3) electron shuttle system at the anode). Additionally, to prolong the enzyme lifetime and increase the power output, all of the recombinant enzymes that originated from thermophiles were expressed in Escherichia coli and purified to homogeneity. The maximum power density of the EFC with two dehydrogenases was 0.0203 mW cm(-2) in 10 mM glucose at room temperature, which was 32% higher than that of an EFC with one dehydrogenase, suggesting that the deep oxidation of glucose had occurred. When the temperature was increased to 50°C, the maximum power density increased to 0.322 mW cm(-2), which was approximately eight times higher than that based on mesophilic enzymes at the same temperature. Our results suggest that the deep oxidation of glucose could be achieved by using multiple dehydrogenases in synthetic cascade pathways and that high power output could be achieved by using thermostable enzymes at elevated temperatures.
The open reading frame TM1080 from Thermotoga maritima encoding ribose-5-phosphate isomerase type B (RpiB) was cloned and over-expressed in Escherichia coli BL21 (DE3). After optimization of cell culture conditions, more than 30% of intracellular proteins were soluble recombinant RpiB. High-purity RpiB was obtained by heat pretreatment through its optimization in buffer choice, buffer pH, as well as temperature and duration of pretreatment. This enzyme had the maximum activity at 70°C and pH 6.5-8.0. Under its suboptimal conditions (60°C and pH 7.0), k(cat) and K(m) values were 540s(-1) and 7.6mM, respectively; it had a half lifetime of 71h, resulting in its turn-over number of more than 2×10(8)mol of product per mol of enzyme. This study suggests that it is highly feasible to discover thermostable enzymes from exploding genomic DNA database of extremophiles with the desired stability suitable for in vitro synthetic biology projects and produce high-purity thermoenzymes at very low costs.
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