Search

Background: The restoration of dental implants presents a unique challenge due to the intrinsic biomechanical differences between osseointegrated implants and natural teeth, and their subsequent responses to occlusal loading. However, controversy exists regarding the role that occlusion plays in the physiology of the peri‐implant complex. Purpose: To provide an overview of the scientific literature regarding occlusion as it relates to implant dentistry and peri‐implant disease. Materials and Methods: This article presents a narrative review on occlusal loading and its potential effects on the peri‐implant complex, as well as some generally accepted guidelines for occlusion in implant dentistry. Results and Conclusions: Although there is strong evidence linking occlusal factors to mechanical complications of dental implants, the same cannot be said regarding biological complications. There is no clear scientific evidence on the relationship between occlusal overload and peri‐implant disease. However, occlusal overload may be an accelerating factor for peri‐implant disease in the presence of inflammation. As the biomechanical properties of dental implants differ from that of the natural dentition, modifications to classic concepts of occlusion may be necessary when dental implants are involved. Thus, clinical recommendations are proposed which function to minimize unfavorable occlusal forces on implant restorations and reduce the associated biological and mechanical complications. [ABSTRACT FROM AUTHOR]

The spin Seebeck effect (SSE) is an emergent thermoelectric phenomenon, which enables a thermal-to-electrical energy conversion via the thermal injection of spin currents from a ferromagnet (FM) into an attached paramagnetic metal (PM). Recent studies have revealed that the SSE is very sensitive to the PM/FM interface condition, suggesting a potential way to enhance the SSE by controlling the interface condition. However, most of the previous studies are limited to conventional Pt/bulk single-crystal or thin-film YIG systems, lacking consideration for mesoscale surface defects such as pores and grain grooves, which frequently exist in more prevalent bulk polycrystalline magnets. Here, we investigate the effect of interface condition on the longitudinal SSE (LSSE) in a Pt/polycrystalline NiFe2O4 (NFO) slab system. Different interface conditions are induced by treating the surface of NFO slabs with varying combinations of polishing force (Fp) and post-annealing temperature (Ta) before the Pt deposition. The resultant LSSE signals show strong correlations with different interface parameters. In particular, we find that mesoscale surface defects (cracks, pores, and grain grooves) and the surface roughness play a crucial role in determining the magnitude of LSSE signals and demonstrate that those parameters can be deliberately controlled by properly choosing Fp and Ta. We report one sample with a spin Seebeck coefficient of 0.58 μV/K, which is significantly larger than that of bulk polycrystalline magnets reported thus far. [ABSTRACT FROM AUTHOR]

The accurate diagnosis of individual tooth prognosis has to be determined comprehensively in consideration of the broader treatment plan. The objective of this study was to establish an effective artificial intelligence (AI)-based module for an accurate tooth prognosis decision based on the Harvard School of Dental Medicine (HSDM) comprehensive treatment planning curriculum (CTPC). The tooth prognosis of 2359 teeth from 94 cases was evaluated with 1 to 5 levels (1—Hopeless, 5—Good condition for long term) by two groups (Model-A with 16, and Model-B with 13 examiners) based on 17 clinical determining factors selected from the HSDM-CTPC. Three AI machine-learning methods including gradient boosting classifier, decision tree classifier, and random forest classifier were used to create an algorithm. These three methods were evaluated against the gold standard data determined by consensus of three experienced prosthodontists, and their accuracy was analyzed. The decision tree classifier indicated the highest accuracy at 0.8413 (Model-A) and 0.7523 (Model-B). Accuracy with the gradient boosting classifier and the random forest classifier was 0.6896, 0.6687, and 0.8413, 0.7523, respectively. Overall, the decision tree classifier had the best accuracy among the three methods. The study contributes to the implementation of AI in the decision-making process of tooth prognosis in consideration of the treatment plan. [ABSTRACT FROM AUTHOR]

A transverse thermoelectric (TE) device that employs the Nernst effect can generate an electrical potential by applying a temperature gradient perpendicular to the magnetic field. Anomalous Nernst effect (ANE)-based TE materials have been proposed for transverse TE devices due to their advantage of utilizing internal magnetic field of the materials, which offers the benefit of operating without an external magnetic field. To increase the output voltage of transverse TE devices utilizing ANE, materials with higher ANE coefficients, S ANE , are required. Currently, S ANE reaches ∼6 μV/K at 300 K; however, it is still lower than the Seebeck coefficient of commercial Bi-Te-based TE materials. As proven in conventional TE research, a meticulous design of device structure has the potential to significantly amplify the output voltage for the given material properties. This study proves the same strategy works for transverse TE devices. We demonstrate that a novel device design, where a shape-engineered tilted-leg thermopile structure is employed, significantly enhance the output voltage in the transverse direction. Owing to shape engineering of the leg geometry, an additional temperature gradient develops along the long direction of the leg, which is perpendicular to the direction of the applied temperature gradient, thereby generating an additional Seebeck voltage V SE that adds to the ANE voltage V ANE. We further show that a simple adjustment of electrode position within the device can further increase V SE. The tilted leg device with electrode adjustment demonstrates a 990% enhanced transverse output voltage compared to that of conventional rectangular leg thermopile-structured devices, wherein only the ANE occurs. This combined output voltage from both the Seebeck effect and ANE is equivalent to what could be achieved by employing materials with the S ANE value of 22.8 μV/K. This value surpasses the S ANE of state-of-the-art ANE materials and devices currently available. The numerical analysis shows the tendencies of the electrical and thermal outputs of the tilted-leg device, which guides a way to further improve the output voltage. Our study paves a way to develop highly efficient transverse TE devices that can overcome intrinsic materials challenges by utilizing the degree of freedom of device design. • A tilted-leg thermopile is proposed as transverse thermoelectric device. • The proposed system utilizes both Seebeck effect and anomalous Nernst effect. • Output voltage increased 990% compared to conventional transverse TE structure. • The proposed system is efficient for materials with low anomalous Nernst angle. • Our work offers a potential platform for transverse TE devices. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate synchronous multiple primary neoplasms of gynecologic origin in terms of clinical features, diagnosis, treatment, and relapse. Seven patients treated from 2012 to 2017 were studied; five of whom had synchronous multiple primary neoplasms associated with endometrial cancer. Two patients recurred and additional chemotherapy was performed. Synchronous multiple primary neoplasms have a better prognosis than single metastatic tumors, but they should be followed up carefully, as they tend to recur in the latter half of treatment. The authors herein report these seven cases along with a brief review of the literature. [ABSTRACT FROM AUTHOR]

Objective: There exist several treatment planning and clinical challenges when treating over‐retained primary teeth with dental implants—especially in the esthetic zone where the existing hard and soft tissue positions are not in harmony with adjacent dentition and do not serve as reliable landmarks for implant placement and restoration. In this report, we highlight some of the key aspects for achieving predictable treatment outcomes for implant restorations replacing over‐retained primary teeth in the esthetic zone. Clinical considerations: This clinical report describes the treatment of a patient who presented with over‐retained deciduous canines consequent to congenitally missing maxillary lateral incisors. The deciduous canines were deemed hopeless, and subsequently replaced with immediately placed implants following a computer‐guided protocol. The optimal implant positions were determined through a diagnostic wax‐up correcting the existing gingival discrepancies with the adjacent teeth. Existing periapical infections were addressed utilizing a vestibular approach to minimize the postoperative recession and scarring and achieve a more predictable esthetic outcome. Final restorations were fabricated with all ceramic materials for optimal esthetics. Conclusion: When planning for implants to replace over‐retained primary teeth, it is essential to visualize the desired contours of the final restorations and correct the level of the existing gingival discrepancies by planning the proper implant position and angulation in relation to the adjacent teeth and gingival positions. Clinical significance: Careful treatment planning coupled with a guided implant workflow allows for a successful surgical and esthetic outcome for the replacement of over‐retained primary teeth with implant restorations. [ABSTRACT FROM AUTHOR]

Hexavalent chromium is extremely toxic and increasingly prevalent owing to industrialisation, thereby posing serious human health and environmental risks. Therefore, new approaches for detoxifying high concentrations of Cr (VI) using an ultralow amount of catalyst with high recyclability are increasingly being considered. The catalytic conversion of Cr (VI) into Cr (III) was previously reported; however, it required a large amount of catalyst to reduce a low concentration of Cr (VI); further, pH adjustment and catalyst separation had to be performed, causing issues with large-scale remediation. In this study, an unprecedented eco-friendly and cost-effective method was developed for the synthesis of Pd nanoparticles (PdNPs) with a significantly narrow size distribution of 3–25 nm. PdNPs demonstrated the presence of elemental Pd with the zero oxidation state when analysed by energy-dispersive X-ray analysis and X-ray photoelectron spectroscopy. The PdNPs could detoxify a high concentration of Cr (VI), without the need to adjust the pH or purify the nanoparticles for reusability. The reusability of the PdNPs for the catalytic conversion of Cr (VI) into Cr (III) was >90% for subsequent cycles without the further addition of formic acid. Thus, the study provides new insights into the catalytic reclamation of Cr (VI) for industrial wastewater treatment. [ABSTRACT FROM AUTHOR]

Curcumin, an extensively utilized natural pigment in the food industry, has attracted considerable attention due to its potential therapeutic effects, such as anti-tumorigenic and anti-inflammatory activities. The enzyme 17β-Hydroxysteroid dehydrogenase 1 (17β-HSD1) holds a crucial position in oestradiol production and exhibits significant involvement in oestrogen-responsive breast cancers and endometriosis. This study investigated the inhibitory effects of curcuminoids, metabolites, and analogues on 17β-HSD1, a key enzyme in oestradiol synthesis. Screening 10 compounds, including demethoxycurcumin (IC50, 3.97 μM) and dihydrocurcumin (IC50, 5.84 μM), against human and rat 17β-HSD1 revealed varying inhibitory potencies. These compounds suppressed oestradiol secretion in human BeWo cells at ≥ 5–10 μM. 3D-Quantitative structure-activity relationship (3D-QSAR) and molecular docking analyses elucidated the interaction mechanisms. Docking studies and Gromacs simulations suggested competitive or mixed binding to the steroid or NADPH/steroid binding sites of 17β-HSD1. Predictive 3D-QSAR models highlighted the importance of hydrophobic regions and hydrogen bonding in inhibiting 17β-HSD1 activity. In conclusion, this study provides valuable insights into the inhibitory effects and mode of action of curcuminoids, metabolites, and analogues on 17β-HSD1, which may have implications in the field of hormone-related disorders. [ABSTRACT FROM AUTHOR]

Uterine smooth-muscle tumors of uncertain malignant potential(STUMP) cannot be categorized as benign or malignant. In this paper, the authors describe several cases presenting with STUMP. The authors reported five cases of STUMP treated in Soonchunhyang University Bucheon Hospital from 2013 to 2016. Four patients remain recurrence free (26-60 months) and one patient was lost to followup one month after STUMP diagnosis, revisited three years later, and was diagnosed with high-grade (Stage IIa) ovarian serous carcinoma after a staging operation. The authors suggested that regular follow-up after surgery was important in STUMP, and more aggressive surgical management, including salpingo-oophorectomy, should be considered. [ABSTRACT FROM AUTHOR]

Abstract The biosynthesis of nanomaterials is a huge and intensifying field of research due to their application in various areas, in particular the biomedical and pharmaceutical fields. In this review, we focused on the biosynthesis of both metallic and semiconductor nanomaterials and their application in biomedicine and pharmaceutics. In order to meet an exponentially increasing need for nanostructured materials, the biological route for the synthesis of nanomaterials will have to be explored, offering advantages over chemical and physical methods as a simpler, more cost effective, and environmentally friendly method, and for which there is no need to use high pressure and temperatures or toxic chemicals. This review discusses in detail the potential role of bioreducing and capping/stabilizing agents in biosynthesis. This review also investigates the application of various biosynthetic nanomaterials as antimicrobial materials, in clinical detection, for drug delivery and wound-healing, and as anti-diabetic materials. Graphical abstract Unlabelled Image Highlights • Focused on the biosynthesis of metallic and semiconductor nanostructures • Nanomaterials biosynthesis using plants, fungi and bacteria • Various morphology of nanostructures • Enlighten the mechanistic approach of biosynthesis • Application of biogenic nanomaterials in biomedical and pharmaceutical application [ABSTRACT FROM AUTHOR]

The 3 µm spectrum of Titan contains line emission and absorption as well as a significant haze continuum. The line emission has been previously analyzed in the literature, but that analysis has not properly included the influence of haze on the line emission. We report a new analysis of the 3 µm HCN emission spectrum using radiative transfer equations that include scattering and absorption by molecules and haze particles at altitudes lower than 500 km, where the influence of haze on the emergent spectrum becomes significant. Taking advantage of the dominance of resonant single scattering in the HCN ν 3 fundamental and of the moderate haze optical thickness of the atmosphere around 3 µm, we adopt single dust and molecular scattering and present a formulation for the radiative transfer process. We evaluate the quantitative influence of haze scattering on the emission line intensities, and derive vertically-resolved single scattering albedos of the haze from model fits. We also present the resulting concentrations of HCN for altitudes below 500 km, where we find that the haze scattering significantly influences the retrieval of the concentrations of HCN. We conclude that the formulation we present is useful for the analysis of the HCN line emission from Titan and other similar hazy planetary or celestial objects. [ABSTRACT FROM AUTHOR]

Objectives The objective of this study was to evaluate whether surface chemistry-controlled TiO2 nanotube structures may serve as a local drug delivery system for zoledronic acid improving implant-bone support. Methods Twenty-four screw-shaped Ti implants with surface chemistry-controlled TiO2 nanotube structures were prepared and divided into a zoledronic acid-formatted test and a native control group. The implants were inserted into contra-lateral femoral condyles in 12 New Zealand White rabbits. Bone support was evaluated using resonance frequency analysis ( RFA) and removal torque ( RTQ), as well as histometric analysis following a 3-weeks healing interval. Results Zoledronic acid-formatted TiO2 nanotube test implants showed significantly improved implant stability and osseointegration measured using RFA and RTQ compared with control ( p < 0.05), and showed significantly enhanced new bone formation within the root of the threads compared with control (p < 0.05). Conclusions TiO2 nanotube implants may prove to be a significant delivery system for drugs or biologic agents aimed at supporting local bone formation. Additional study of candidate drugs/agents, optimized dosage and release kinetics is needed prior to evaluation in clinical settings. [ABSTRACT FROM AUTHOR]

Glomerular damage mediated by glomerulus-infiltrating myeloid-derived cells is a key pathogenic event in lupus nephritis (LN), but the process is poorly understood. Confocal microscopy of kidney sections and flow cytometry analysis of glomerular cells from magnetic bead-purified glomeruli have identified glomerulus-infiltrating leukocyte populations in NZM2328 (NZM) lupusprone mice with spontaneous chronic glomerulonephritis (GN) and anti-glomerular basement membrane-induced nephritis. The occurrence of a major glomerulus-infiltrating CD11b+F4/80-I-A- macrophage population exhibiting the markers programmed death ligand-1 (PD-L1), Mac-2, and macrophage mannose receptor (CD206) and producing Klf4, Il10, Retnla, Tnf, and Il6 mRNA, which are known to be expressed by alternatively activated (M2b) macrophages, correlated with proteinuria status. In NZM mice with spontaneous LN, glomerular macrophage infiltration is predominant. CD11b+F4/80-I-A- intraglomerular macrophages and polymorphonuclear neutrophils (PMN) are important in inducing GN, as anti-CD11b and -ICAM-1 mAb inhibited both proteinuria and macrophage and PMN infiltration. The predominant and high expression of PD-L1 by CD11b+F4/80-I-A- glomerular macrophages in kidneys of mice with GN and the inhibition of proteinuria by anti-PD-L1 mAb supported the pathogenic role of these macrophages but not the PD-L1" PMN in GN development and in inducing podocyte damage. In NZM mice with spontaneous chronic GN and severe proteinuria, few glomerulus-infiltrating PMN were found, leaving macrophages and, to a less extent, dendritic cells as the major infiltrating leukocytes. Taken together, these data support the important pathogenic effect of CD11b+F4/80-I-A- M2b-like glomerulus-infiltrating macrophages in LN and reinforce macrophages as a promising target for GN treatment. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the role of bone marrow stromal cell antigen-1 (Bst1; also known as CD157) in acute kidney injury (AKI). Bst1 is a cell surface molecule with various enzymatic activities and downstream intracellular signaling pathways that modulate the immune response. Previous research has linked Bst1 to diseases such as ovarian cancer, Parkinson's disease, and rheumatoid arthritis. We used bilateral ischemia-reperfusion injury (IRI) as an AKI model and created bone marrow chimeric mice to evaluate the role of Bst1 in bone marrow-derived cells. We also used flow cytometry to identify Bst1/CD157 expression in hematopoietic cells and evaluate immune cell dynamics in the kidney. The findings showed that Bst1-deficient (Bst1-/-) mice were protected against renal bilateral IRI. Bone marrow chimera experiments revealed that Bst1 expression on hematopoietic cells, but not parenchymal cells, induced renal IRI. Bst1 was mainly found in B cells and neutrophils by flow cytometry of the spleen and bone marrow. In vitro, migration of neutrophils from Bst1-/- mice was suppressed, and adoptive transfer of neutrophils from wild-type Bst1+/+ mice abolished the renal protective effect in Bst1 knockout mice. In conclusion, the study demonstrated that Bst1-/- mice are protected against renal IRI and that Bst1 expression in neutrophils plays a crucial role in inducing renal IRI. These findings suggest that targeting Bst1 in neutrophils could be a potential therapeutic strategy for AKI. NEW & NOTEWORTHY Acute kidney injury (AKI), a serious disease for which there is no effective Federal Drug Administration-approved treatment, is associated with high mortality rates. Bone marrow stromal cell antigen-1 (Bst1) is a cell surface molecule that can cause kidney fibrosis, but its role in AKI is largely unknown. Our study showed that Bst1-/- mice revealed a protective effect against renal bilateral ischemia-reperfusion injury (IRI). Adoptive transfer studies confirmed that Bst1 expression in hematopoietic cells, especially neutrophils, contributed to renal bilateral IRI. [ABSTRACT FROM AUTHOR]

Both the lpr gene defect and interleukin 2-targeted mutation (IL-2 KO) in mice are lethal. Interestingly, mice bearing both mutations live significantly longer than mice with either of the single mutant genes, approximating the life span of normal controls. They do not display the major disease phenotypes of lpr and IL-2 KO mice. Systemic autoimmune response, the accumulation of the abnormal CD4[sup -]CD8[sup -]B220[sup +] double-negative T cells, kidney disease pathology, anemia, colon damage, and lethality are prevented. Our data indicate that IL-2 is mandatory for the expansion of auto-reactive T cells in lpr mice and that CD95 (Fas) is the critical target for the development of anemia and ulcerative colitis in IL-2 KO mice in which CD178 (FasL) on intraepithelial T cells is the major effector responsible for colon damage and lethality. [ABSTRACT FROM AUTHOR]

Objective: Compared with standard, whole-gland (WG) therapies for prostate cancer, focal approaches may provide equivalent oncologic outcomes with fewer adverse effects. The purpose of this study was to compare organ-at-nsk (OAR) dosimetry between hemigland (HG) and WG stereotactic body radiotherapy (SBRT) plans. Methods: Volumetric-modulated arc radiotherapy-based SBRT plans were designed to treat the loft HG, right HG and WG in eight patients, using five fractions of 8Gy. OARs of interest included the contralateral HG, rectum, urinary bladder, urethra, penile bulb and contralateral neurovascular bundle. Results: Rectal V80% (the percentage of a normal structure receiving a dose of 80%) and V90% were significantly lower with HG plans than with WG plans (median values of 4.4 vs 2.5cm3 and 2.1 vs 1.1 cm3, respectively, p< 0.05 by Student's t-test). Bladder V50% was also reduced significantly m HG plans (32.3 vs 17.4 cm3, p<0.05). with a trend towards reduction of V100% (3.4 vs 1.3cm3, p = 0.09). Urethral maximum dose and mean doses to the penile bulb and contralateral neurovascular bundle were also reduced significantly (42.0 vs 39.7Gy, p< 0.00001: 13.3 vs 9.2Gy, p < 0.05; and 40.2 vs 19.3 Gy. p < 0.00001. respectively). Conclusion: Targeting an HG volume rather than a WG volume when delivering SBRT can offer statistically significant reductions for all OARs. Given the large magnitude of the reduction in dose to these OARs. it is anticipated that HG SBRT could offer a superior toxicity profile when compared with WG SBRT. This is likely to be most relevant m the context of salvaging a local failure after radiation therapy. Advances in knowledge: The dosimetric feasibility of HG SBRT is demonstrated When compared with WG SBRT plans, the HG plans demonstrate statistically significant and large magnitude reduction in doses to the rectum, bladder, urethra, penile bulb and contralateral neurovascular bundle, suggesting the possibility of improved toxicity outcomes with HG SBRT This is likely to be most relevant in the context of salvaging a local failure after radiation therapy. [ABSTRACT FROM AUTHOR]

Objective The accuracy of digital impressions greatly influences their clinical viability in implant restorations. The aim of this study was to compare the accuracy of gypsum models acquired from the conventional implant impression to digitally milled models created from direct digitalization by three-dimensional analysis. Materials and Methods Thirty gypsum and 30 digitally milled models, impressed directly from a reference model, were prepared. The models and reference model were scanned by a laboratory scanner, and 30 surface tessellation language datasets from each group were imported to an inspection software program. The datasets were aligned to the reference dataset by a repeated best-fit algorithm, and 10 specified contact locations of interest were measured in mean volumetric deviations. The areas were pooled by cusps, fossae, interproximal contacts, horizontal and vertical axes of implant position and angulation. The pooled areas were statistically analysed by comparing each group to the reference model to investigate the mean volumetric deviations accounting for accuracy and standard deviations for precision. Results Milled models from digital impressions had comparable accuracy to gypsum models from conventional impressions. However, differences in fossae and vertical displacement of the implant position from the gypsum and digitally milled models compared to the reference model exhibited statistical significance ( P < 0.001, P = 0.020, respectively). Conclusion Milled models from digital impression are comparable to gypsum models from conventional impression. [ABSTRACT FROM AUTHOR]

We report on the discovery of a macroscopic quantum phenomenon, referred to as supernonlocality, in the Weyl state—a topological metal exhibiting both surface and bulk topological transport. Supernonlocality is characterized by a comparable magnitude of nonlocal resistance to local resistance, indicating a global transport property. Remarkably, we observe a colossal nonlocal decay length of 0.6 mm, surpassing other semimetals in terms of nonlocal phenomena. This unprecedented behavior is found to be positively correlated with the system's nonlinear conductivity, suggesting that macroscopic supernonlocality arises from chiral charge pumping through a one-dimensional topological channel. Our findings provide insight into the manifestation of macroscopic quantum phenomena in topological metals and pave the way for the development of topological nonlocal electronics. [ABSTRACT FROM AUTHOR]

Förster resonance energy transfer (FRET) occurs when the distance between a donor fluorophore and an acceptor is within 10 nm, and its application often necessitates fluorescent labeling of biological targets. However, covalent modification of biomolecules can inadvertently give rise to conformational and/or functional changes. This review describes the application of intrinsic protein fluorescence, predominantly derived from tryptophan (λEX ~ 280 nm, λEM ~ 350 nm), in protein-related research and mainly focuses on label-free FRET techniques. In terms of wavelength and intensity, tryptophan fluorescence is strongly influenced by its (or the protein's) local environment, which, in addition to fluorescence quenching, has been applied to study protein conformational changes. Intrinsic Förster resonance energy transfer (iFRET), a recently developed technique, utilizes the intrinsic fluorescence of tryptophan in conjunction with target-specific fluorescent probes as FRET donors and acceptors, respectively, for real time detection of native proteins. [ABSTRACT FROM AUTHOR]

A new constitutive model, which is a modification from Gao's second constitutive model, has been introduced by using the finite deformation theory. The new model fulfils the condition that strain energy becomes zero under no deformation. For incompressible polymer rubber materials, when n=1 and α=0, the new constitutive relation may be simplified to the Mooney-Rivlin model; when n=1 and α=1, the new constitutive relation may be simplified to the Neo-Hookean model. The discussions of basic finite deformation examples illustrate how the new constitutive model reasonably describes the deformation properties of polymer rubber materials, and how the applied range of polymer rubber materials have been broadened by using the new constitutive model. [ABSTRACT FROM AUTHOR]

Highlights: [•] Updated radiative transfer programs to construct a 3-mm emission model of CH4. [•] Compared the model with 3-mm ISO data of Jupiter to derive microbar CH4 mixing ratios. [•] Found at least 10 times smaller than CH4 mixing ratios from Galileo probe analysis. [•] Provided discussions on the photochemistry and vertical transport in the stratosphere. [Copyright &y& Elsevier]

The paper describes the development and validation of an efficient and cost effective method for the prediction of the NOx emissions of turbulent gas turbine burners in the early burner design phases, which are usually focused on the optimization of the swirler aerodynamics and the fuel-air mixing. Since the method solely relies on nonreacting tests of burner models in the water channel, it can be applied before any test equipment for combustion experiments exists. In order to achieve optimum similarity of fuel-air mixing in the water channel tests with engine operation the model is operated at the engine momentum ratio. During the laser induced fluorescence (LIF) measurements the water flow representing the fuel is doped with fluorescent dye, a plane perpendicular to the length axis near the burner exit plane is illuminated with a 5W Ar-ion laser, and the fluorescence is recorded with a video camera from downstream. From the video sequencer the local probability density functions (PDF) of the dye concentration fluctuations are calculated from the data. Furthermore, the time mean velocity fields are measured with particle image velocimetry (PIV). The PDFs of the local equivalence ratio are derived from the LIF data. Assuming flamelets, the NOx generation in the entire equivalence ratio range observed in the water channel tests is computed using the unstrained freely propagating one-dimensional flame model in Camera and the GR13.0 reaction scheme. Although neither flame stretch nor post flame NOx generation were considered, the computed NOx values were in excellent agreement with the experimental data from perfectly premixed combustion experiments. The local time averaged NOx mole fraction is obtained by integrating the flamelet NOx over the mixture PDF. Finally the global NOx emission of the burner at the considered operating point is obtained by spatial integration, considering the measured velocity field. The method was validated using a conical swirl burner with two fuel injection stages, allowing the degree of premixedness to be adjusted over a wide range, depending on the specific fuel injection scenario. For the case with fuel injection along the air inlet slots NOx values slightly above the minimum NOx limit for perfectly premixed combustion were computed. This is consistent with the emission measurements and indicates the finite mixing quality of this injection method. In the partially premixed regime the configurations with potential for low NOx emissions were reliably identified with the LIF and PIV based water channel method. The method also shows the steep increase of the NOx emissions with the decreasing degree of premixing observed in the experiments, however, quantitative predictions would have required a postprocessing of the data from the LIF mixing study with a higher spatial resolution than available. [ABSTRACT FROM AUTHOR]

Abstract: Kidney ischemia–reperfusion injury (IRI) occurs as a result of complex interactions of kidney parenchymal cells and immune cells that are initiated by hypoxic damage of parenchymal cells. In particular, tubular epithelial cells (TECs) not only are susceptible to ischemia but also have an auto-loop system to amplify renal inflammation caused by ischemia and reperfusion. Since endogenous TLR2 ligands released from TECs trigger renal inflammation leading to kidney IRI in an autocrine manner, we hypothesized that local infusion of TLR2 blockers would prevent kidney IRI. In this study, we demonstrated that injection of antagonist anti-TLR2 mAb through the renal vein after cross-clamping significantly reduced the recruitment of NK cells to the kidney after IRI, a phenomenon that is governed by TLR2 signaling in TECs. In addition, intrarenal blocking of TLR2 signaling was shown to inhibit NK cell-mediated neutrophil infiltration and subsequent renal damage. Overall, our simple experiment system will be of help in testing the efficacy of candidate blockers targeting kidney parenchymal cells in inhibition of kidney IRI. [Copyright &y& Elsevier]

Abstract: Orbit manoeuvre of low Earth orbiting (LEO) debris using ground-based lasers has been proposed as a cost-effective means to avoid debris collisions. This requires the orbit of the debris object to be determined and predicted accurately so that the laser beam can be locked on the debris without the loss of valuable laser operation time. This paper presents the method and results of a short-term accurate LEO (<900km in altitude) debris orbit prediction study using sparse laser ranging data collected by the EOS Space Debris Tracking System (SDTS). A main development is the estimation of the ballistic coefficients of the LEO objects from their archived long-term two line elements (TLE). When an object is laser tracked for two passes over about 24h, orbit prediction (OP) accuracy of 10–20arc seconds for the next 24–48h can be achieved – the accuracy required for laser debris manoeuvre. The improvements in debris OP accuracy are significant in other applications such as debris conjunction analyses and the realisation of daytime debris laser tracking. [Copyright &y& Elsevier]

Target identification of biologically active molecules such as natural products, synthetic small molecules, peptides, and oligonucleotides mainly relies on affinity chromatography, activity-based probes, or photoaffinity labeling (PAL). Amongst them, activity-based probes and PAL have offered great advantages in target identification technology due to their ability to form covalent bonds with the corresponding targets. Activity-based probe technology mainly relies on the chemical reactivity of the target proteins, thereby limiting the majority of the biological targets to enzymes or proteins which display reactive residues at the probe-binding site. In general, the probes should bear a reactive moiety such as an epoxide, a Michael acceptor, or a reactive alkyl halide in their structures. On the other hand, photoaffinity probes (PAPs) are composed of a target-specific ligand and a photoactivatable functional group. When bound to the corresponding target proteins and activated with wavelength-specific light, PAPs generate highly reactive chemical species that covalently cross-link proximal amino acid residues. This process is better known as PAL and is widely employed to identify cellular targets of biologically active molecules. This review highlights recent advances in target identification by PAL, with a focus on the structure and chemistry of the photoaffinity probes developed in the recent decade, coupled to the target proteins identified using these probes. [ABSTRACT FROM AUTHOR]

We retrieved optical-depth spectra of the Titanian haze in the range 1-5 μm from solar occultation data obtained by the Cassini/Visual Infrared Mapping Spectrometer (VIMS) at altitudes of 59-502 km. Only limited wavelength intervals within this spectral range have been analyzed before. The haze spectra we retrieved are mostly similar to those of alkane particles (or powders), with three major absorption peaks typical of alkane powders at 2.3, 3.4, and 4.3 μm. This result suggests that at least in the ~60-500 km altitude range, the Titanian haze is mostly composed of alkane particles, possibly with some trace impurities. The absence of the 3.0 and 4.6 μm features excludes the molecules containing NH and CN bonds that are typical of laboratory-made tholins reported in the literature. The alkane-like spectral characteristics of the haze we observed at ~60-500 km differ from previous results obtained at different or overlapping altitudes: a) the presence of aromatic compounds derived from solar-pumped emissions observed at high altitude (600-1250 km) by Cassini/VIMS near 3.3 μm; and b) the detection of HCN and NH3 in the cores of haze particles collected at low altitude (20-130 km) by the Huygens/Aerosol Collector and Pyrolyser (ACP). We suggest that these different characteristics arise from different structural layers formed by coagulation/coalescence during particle sedimentation. [ABSTRACT FROM AUTHOR]

Objectives The aim of this pilot study was to evaluate the efficiency, difficulty and operator's preference of a digital impression compared with a conventional impression for single implant restorations. Materials and methods Thirty HSDM second year dental students performed conventional and digital implant impressions on a customized model presenting a single implant. The outcome of the impressions was evaluated under an acceptance criteria and the need for retake/rescan was decided. The efficiency of both impression techniques was evaluated by measuring the preparation, working, and retake/scan time (m/s) and the number of retakes/rescans. Participants' perception on the level of difficulty for the both impressions was assessed with a visual analogue scale ( VAS) questionnaire. Multiple questionnaires were obtained to assess the participants' perception on preference, effectiveness and proficiency. Results Mean total treatment time was of 24:42 m/s for conventional and 12:29 m/s for digital impressions ( P < 0.001). Mean preparation time was of 4:42 m/s for conventional and 3:35 m/s for digital impressions ( P < 0.001). Mean working time including retakes/rescans demanded 20:00 m/s for conventional vs. 8:54 m/s for digital impression ( P < 0.001). On a 0-100 VAS scale, the participants scored a mean difficulty level of 43.12 (±18.46) for conventional impression technique and 30.63 (±17.57) for digital impression technique ( P = 0.006). Sixty percent of the participants preferred the digital impression, 7% the conventional impression technique and 33% preferred either technique. Conclusions Digital impressions resulted in a more efficient technique than conventional impressions. Longer preparation, working, and retake time were consumed to complete an acceptable conventional impression. Difficulty was lower for the digital impression compared with the conventional ones when performed by inexperienced second year dental students. [ABSTRACT FROM AUTHOR]

Abstract: Atmospheric-pressure pure steam torch plasma was generated by making use of 2.45 GHz microwave energy and was used in a coal gasification investigation. The steam torch plasma contains also highly active species, enhancing the chemical reaction rate and eliminating the need for catalysts in material processing. Fine coal powders with an average particle size of 70 μm were delivered through a feeder and used in the experiment. The brown coal from Indonesia with ash and moisture content of 38.12% was injected to the steam torch with microwave power of 4 kW. From the experimental data showing the relative concentrations of synthesized gas species versus the ratio of coal to steam for brown coal at the microwave power of 4 kW, the relative concentrations of synthesized gases at a ratio of 1.36 of coal to steam was 48% of hydrogen, 23% of carbon monoxide, 25% of carbon dioxide and 4% of methane. The further increase of coal to steam ratio did not much reduce carbon dioxide concentration. We note that a low-grade coal can also be well gasified in steam plasma torch. [Copyright &y& Elsevier]

Abstract: The Foxp3+CD4+ regulatory T-cell (Treg)-deficient Scurfy (Sf) mice rapidly develop severe inflammation in the skin and lungs with expanded Th subsets bearing increased expression of various chemokine/chemoattractant/retention receptor genes (CRG). Nine different double mutants were generated to elucidate their roles in the skin and lung inflammation. The expanded Th2 response and the increased expression of several CRG for the skin and lung inflammation were inhibited in Sf.Il2 −/− mice as previously described using microarray analysis. Herein in a reciprocal approach, we demonstrated that Sf.Il4 −/− and Sf.Stat6 −/− mice, despite lacking Th2 cytokines IL-4, IL-5, and IL-13, as well as the IL-4/STAT6-dependent CRG expression, the inflammation in the skin and lungs remained. The effect of the other Th1 cytokine IFN-γ was studied in Sf.Ifng −/− mice in which the multi-organ inflammation (MOI) was delayed but fully developed afterward with enhanced CRG expression except for the IFN-γ-dependent Cxcr3 in CD4+ T-cells. Similarly, a transient delay of MOI was observed for Sf.Itgae −/− mice but their Th subsets and the critical CRG expansion remained. Ltb4r1 −/−, Alox5 −/−, Cx3cr1 gfp/gfp , or Il10 −/− mutant genes also failed to effectively block inflammation in the skin and lungs in Sf mice. Our study has identified a novel function of IL-2 as a powerful Th1 cytokine that induces a panel of CRG in Th subsets required for skin and lung inflammation in Sf mice. The CRG panel induced by IL-2 but not by IL-4 or IFN-γ explains the apparent “organ-specific” display of the skin and lung inflammation in Sf mice. [Copyright &y& Elsevier]

Abstract: This paper presents a new method of deriving atmospheric mass densities with a high temporal resolution from precise orbit data of low earth orbiting (LEO) space objects. This method is based on the drag perturbation equation of the semi-major axis of the orbit of LEO space objects which relates the change rate of the semi-major axis to the atmospheric mass density. The effectiveness of the new method is evaluated using the GFZ-ISDC GPS rapid science orbit (RSO) products of the CHAMP satellite over a time period of 3months. The densities derived using this new method and obtained from accelerometer data are compared and good agreements are achieved. An example of using the derived density to generate good orbit prediction for CHAMP is presented. [Copyright &y& Elsevier]

Abstract: The CD25+Foxp3+ regulatory T-cells (Treg) that had lost CD25 and Foxp3 in vivo (ex-Treg) exist but are difficult to study. We generated antigen (Ag)-specific Treg hybridomas from iTreg clones (iTreg-hyb) using iTreg of DO11.10.Foxp3-GFP mice and presented evidence that they behave like ex-Treg. The iTreg-hyb displayed little CD25 and Foxp3-GFP but strong expression could be induced with OVA323–339 in the presence of Ag-presenting cells, rIL-2 and rTGF-β1. They displayed all of the iTreg-associated markers examined except CTLA-4, the latter was also absent in the ex-Treg. They lacked the Helios transcription factor, suggesting they were derived from iTreg. Similar to ex-Treg, the iTreg-hyb produced high level of IL-2 and Foxp3 under specific activation conditions. Two unusual properties were observed. First, the ability to induce Foxp3-GFP upon activation is progressively lost in culture over a period of 2–4 weeks. Second, Rag2−/− spleen cells alone selectively induced Foxp3-GFP expression albeit 30 times less efficient than Ag-specific activation. We identified cell-free supernatant, IL-6, IL-9, and IL-27 as Foxp3-inducing factors. Our study has significant implications to the stability, plasticity and fate of Treg. The usefulness and limitation of iTreg-hyb as a novel tool to study Foxp3 regulation and the fate of specific Treg subsets are discussed. [Copyright &y& Elsevier]

Abstract: Recently, an unidentified 3.3–3.4μm feature found in the solar occultation spectra of the atmosphere of Titan observed by Cassini/VIMS was tentatively attributed to the C–H stretching mode of aliphatic hydrocarbon chains attached to large organic molecules, but without properly extracting the feature from adjacent influences of strong CH4 and weak C2H6 absorptions (). In this work, we retrieve the detailed spectral feature using a radiative transfer program including absorption and fluorescent emission of both molecules, as well as absorption and scattering by haze particles. The spectral features of the haze retrieved from the VIMS data at various altitudes are similar to each other, indicating relatively uniform spectral properties of the haze with altitude. However, slight deviations observed near 127km and above 300km suggest inhomogeneity at these altitudes. We find that the positions of the major spectral peaks occur at 3.33–3.37μm, which are somewhat different from the typical 3.3μm aromatic or 3.4μm aliphatic C–H stretches usually seen in the spectra of dust particles of the interstellar medium and comets. The peaks, however, coincide with those of the solid state spectra of C2H6, CH4, and CH3CN; and a broad shoulder from 3.37 to 3.50μm coincides with those of C5H12 and C6H12 as well as those of typical aliphatic C–H stretches. This result combined with high-altitude (∼1000km) haze formation process recently reported by opens a new question on the chemical composition of the haze particles. We discuss the possibility that the 3μm feature may be due to the solid state absorption bands of these molecules (or some other molecules) and we advocate additional laboratory measurements for the ices of hydrocarbon and nitrogen-bearing molecules present in Titan''s atmosphere for the identification of this 3μm feature. [Copyright &y& Elsevier]

Abstract: We present latitudinally-resolved high-resolution (R =37,000) pole-to-pole spectra of Jupiter in various narrow longitudinal ranges, in spectral intervals covering roughly half of the spectral range 2.86–3.53μm. We have analyzed the data with the aid of synthetic spectra generated from a model jovian atmosphere that included lines of CH4, CH3D, NH3, C2H2, C2H6, PH3, and HCN, as well as clouds and haze. Numerous spectral features of many of these molecular species are present and are individually identified for the first time, as are many lines of and a few unidentified spectral features. In both polar regions the 2.86–3.10-μm continuum is more than 10 times weaker than in spectra at lower latitudes, implying that in this wavelength range the single-scattering albedos of polar haze particles are very low. In contrast, the 3.24–3.53μm the weak polar and equatorial continua are of comparable intensity. We derive vertical distributions of NH3, C2H2 and C2H6, and find that the mixing ratios of NH3 and C2H6 show little variation between equatorial and polar regions. However, the mixing ratios of C2H2 in the northern and southern polar regions are ∼6 and ∼3 times, respectively, less than those in the equatorial regions. The derived mixing ratio curves of C2H2 and C2H6 extend up to the 10−6 bar level, a significantly higher altitude than most previous results in the literature. Further ground-based observations covering other longitudes are needed to test if these mixing ratios are representative values for the equatorial and polar regions. [Copyright &y& Elsevier]

Convection enhanced delivery of 6-hydroxydopamine (6-OHDA) to the rat striatum results in a model of Parkinson’s disease. An important feature of this unilateral model is the progressive loss of dopaminergic (DA) neurons over the course of several weeks. To improve the understanding of this model, gene expression changes in the substantia nigra, which contains the DA neuron cell bodies, and the striatum, which contains the DA neuron synaptic terminals, were examined using DNA microarrays. Samples were collected and behavior was analyzed from vehicle and toxin treated animals at 3 days, 1 week, 2 weeks and 4 weeks following 6-OHDA treatment. Tissue DA content was determined and samples from animals which exhibited a substantial depletion of striatal DA were included in the subsequent gene expression analysis. The results of the gene expression analysis indicated that 6-OHDA elicits a vigorous inflammatory response, comprised of several distinct pathways, in the striatum at the earliest time point tested. In contrast, relatively few gene expression changes were observed in the SN at the 3-day time point. In both tissues examined there was evidence for a vigorous inflammatory response at the 1- and 2-week time points, which was substantially diminished by the 4-week time point. Inflammation plays a prominent role in the 6-OHDA model of Parkinson’s disease. [ABSTRACT FROM AUTHOR]

Purpose: To develop a system with which to quantify objectively the heterophoria to be measured throughout eye movement experiments. This study compared precision, resolution and accuracy characteristics of a limbus eye movement tracking system to the alternate cover test and the Maddox rod. Methods: Precision testing was performed using each technique with binocularly-normal subjects at different test sessions. Resolution was measured and compared between the three systems. The heterophoria or phoria was measured from 40 cm/16 inches objectively with the limbus eye movement system and the Maddox rod during a sustained convergence-induced phoria adaptation experiment using physical and haploscope visual targets to compare accuracy. Results: Precision testing quantified that the responses objectively recorded using the limbus tracking system exhibited similar standard deviations to the Maddox rod and the alternate cover test techniques. The limbus tracking method has the ability to quantify the response decay to phoria and has better resolution when compared to the clinical methods. When physical targets were used to induce phoria adaptation, the correlation was significant between the limbus eye movement tracking system and the Maddox rod after near and far adaptation, where the Maddox rod measurements were slightly more esophoric compared to those measured with the limbus tracking system. Conclusion: This objective limbus tracking system offers a better means by which to study the phoria and its adaptation throughout an eye movement experiment. The broader aim of this research is to establish a tool that will further the basic science of oculomotor control and binocular dysfunctions. [ABSTRACT FROM AUTHOR]

Abstract: Jupiter exhibits bright H+ 3 auroral arcs at 3–4 microns that cool the hot (>1000 K) ionosphere above the level through the infrared bands of this trace constituent. Below the level significant cooling proceeds through infrared active bands of CH4, C2H2, and C2H6. We report the discovery of 3-micron line emission from these hydrocarbon species in spectra of the jovian south polar region obtained on April 18 and 20, 2006 (UT) with CGS4 on the United Kingdom Infrared Telescope. Estimated cooling rates through these molecules are , , and , respectively, for a total nearly half that of H+ 3. We derive a temperature of 450 ± 50 K in the bar region from the C2H2 lines. [Copyright &y& Elsevier]

Abstract: Polydiacetylenes (PDAs), which possess unique properties that allow them to change color in response to environmental changes such as variations in pH, temperature, and molecular binding, have been widely investigated as signal transducers in biosensor applications. Most PDA-based sensors reported to date have been evaluated largely on the basis of their ability to detect purified samples, however, and their specificity has rarely been tested. In this study, novel PDAs fabricated on polyvinylidene fluoride (PVDF) strips by photoreaction of composite diacetylene self-assemblies were developed as biosensors, and nonspecific binding to off-target biomolecules was assessed. A mixed PDA surface containing biotin and ethanolamide bound the target, i.e., streptavidin, more specifically than did biotin alone. The optimized PDA biosensor exhibited approximately 2850-fold higher selectivity for streptavidin relative to bovine serum albumin controls. A PDA biosensor that was further prepared showed distinctive signals for the urine of diabetic patients compared to urine samples from healthy/non-diabetic person due to the concentration of microalbuminuria. To our knowledge, this is the first strip-type biosensor fabricated with PDAs and the first PDA-based biosensor that can effectively overcome the problem of nonspecific binding. [Copyright &y& Elsevier]

Abstract: We have constructed synthetic solar spectra for the 2302–4800 cm−1 (2.08–4.34 μm) range, a spectral range where planetary objects mainly emit reflected sunlight, using ATMOS (Atmospheric Trace Molecule Spectroscopy)/Spacelab-3 and Atlas-3 spectra, of which resolution is 0.01 cm−1. We adopted Voigt line profiles for the modeling of line shapes based on an atlas of line identifications compiled by Geller [Geller, M., 1992. Key to Identification of Solar Features. A High-Resolution Atlas of the Infrared Spectrum of the Sun and the Earth Atmosphere from Space. NASA Reference Publ. 1224, vol. III. NASA, Washington, DC, pp. 1–22], who derived solar line positions and intensities from contaminated high-resolution solar spectra obtained by ATMOS/Spacelab-3. Because the ATMOS spectra in these wavelength ranges are compromised by absorption lines of molecules existing in Earth''s high-altitude atmosphere and in the compartment of the spacecraft, the direct use of these high-resolution solar spectra has been inconvenient for the data reductions of planetary spectra. We compared the synthetic solar spectra with the ATMOS spectra, and obtained satisfactory fits for the majority of the solar lines with the exception of abnormal lines, which do not fit with Voigt line profiles. From the model fits, we were able to determine Voigt line parameters for the majority of solar lines; and we made a list of the abnormal lines. We also constructed telluric-line-free solar spectra by manually eliminating telluric lines from the ATMOS spectra and filling the gaps with adjacent continua. These synthetic solar spectra will be useful to eliminate solar continua from spectra of planetary objects to extract their own intrinsic spectral features. [Copyright &y& Elsevier]

Abstract: We report observation and analysis of a high-resolution 2.87–3.54 μm spectrum of the southern temperate region of Saturn obtained with NIRSPEC at Keck II. The spectrum reveals absorption and emission lines of five molecular species as well as spectral features of haze particles. The band of CH3D is detected in absorption between 2.87 and 2.92 μm; and we derived from it a mixing ratio approximately consistent with the Infrared Space Observatory result. The band of C2H2 also is detected in absorption between 2.95 and 3.05 μm; analysis indicates a sudden drop in the C2H2 mixing ratio at 15 mbar (130 km above the 1 bar level), probably due to condensation in the low stratosphere. The presence of the band of C2H6 near 3.07 μm, first reported by Bjoraker et al. [Bjoraker, G.L., Larson, H.P., Fink, U., 1981. Astrophys. J. 248, 856–862], is confirmed, and a C2H6 condensation altitude of 10 mbar (140 km) in the low stratosphere is determined. We assign weak emission lines within the 3.3 μm band of CH4 to the band of C2H6, and derive a mixing ratio of for this species. Most of the C2H6 3.3 μm line emission arises in the altitude range 460–620 km (at ∼μbar pressure levels), much higher than the 160–370 km range where the 12 μm thermal molecular line emission of this species arises. At 2.87–2.90 μm the major absorber is tropospheric PH3. The cloud level determined here and at 3.22–3.54 is 390–460 mbar (∼30 km), somewhat higher than found by Kim and Geballe [Kim, S.J., Geballe, T.R., 2005. Icarus 179, 449–458] from analysis of a low resolution spectrum. A broad absorption feature at 2.96 μm, which might be due to NH3 ice particles in saturnian clouds, is also present. The effect of a haze layer at about 125 km (∼12 mbar level) on the 3.20–3.54 μm spectrum, which was not apparent in the low resolution spectrum, is clearly evident in the high resolution data, and the spectral properties of the haze particles suggest that they are composed of hydrocarbons. [Copyright &y& Elsevier]

A model, introduced earlier for the dynamics of a generic efficiency measure in a population of agents by Majumdar and Krapivsky (Phys. Rev. E 63, 054101 (2001)), is investigated on scale-free networks whose degree distribution follows a power law with the tunable exponent γ. The model shows a delocalization transition from a stagnant phase to a growing one when decreasing the degree exponent γ of scale-free networks. By taking into account the specific dynamical properties of the model and the geometrical properties of scale-free networks, we predict the appearance of this critical transition. This work is useful for understanding these kinds of transitions occurring in many dynamical processes on scale-free networks. [ABSTRACT FROM AUTHOR]

Abstract: We have used synthetic spectra to analyze a medium resolution 2.9–4.2 μm spectrum of Saturn''s temperate region observed at UKIRT using CGS4. The synthetic spectra include CH4, PH3, and NH3 lines, for which mixing ratios were adopted from recent Cassini results. The observed absorption features in the spectrum are well accounted for by lines of these molecular species formed 22 +/− 8 km above the 1 bar pressure level at ∼610 mbar. The influence of optically thin haze particles at higher altitudes on the spectrum is not pronounced, with higher spectral resolution probably required to constrain the effects of haze in this wavelength region. Fluorescent line emission by CH4 in its and bands, detected in the 3.2–3.5 μm region, originates between 400 km (∼0.06 mbar) and 800 km (∼0.01 μbar) above the 1 bar level, with peak contributions from the two major contributing bands at 550 km (∼3 μbar) and 700 km (∼0.1 μbar), respectively. [Copyright &y& Elsevier]

Abstract: Using synthetic spectra derived from an updated model atmosphere together with a continuum model that includes contributions from haze, cloud and ground, we have re-analyzed the recently published (Geballe et al., 2003, Astrophys. J. 583, L39–L42) high-resolution 3 μm spectrum of Titan which contains newly-detected bands of HCN (in emission) and C2H2 and CH3D (in absorption), in addition to previously detected bands of CH4. In the 3.10–3.54 μm interval the analysis yields strong evidence for the existence of a cloud deck or optically thick haze layer at about the 10 mbar (∼100 km) level. The haze must extend well above this altitude in order to mask the strong CH4 lines at 3.20–3.50 μm. These cloud and haze components must be transparent at 2.87–2.92 μm, where analysis of the CH3D spectrum demonstrates that Titan''s surface is glimpsed through a second cloud deck at about the 100 mbar (∼50 km) level. Through a combination of areal distribution and optical depth this cloud deck has an effective transmittance of ∼20%. The spectral shape of Titan''s continuum indicates that the higher altitude cloud and haze particles responsible for suppressing the CH4 absorptions have a largely organic make-up. The rotational temperature of the HCN ranges from 140 to 180 K, indicating that the HCN emission occurs over a wide range of altitudes. This emission, remodeled using an improved collisional deactivation rate, implies mesospheric mixing ratio curves that are consistent with previously predictions. The stratospheric and mesospheric C2H2 mixing ratios are , considerably less than previous model predictions (Yung et al., 1984), but approximately consistent with recent observational results. Upper limits to mixing ratios of HC3N and C4H2 are derived from non-detections of those species near 3.0 μm. [Copyright &y& Elsevier]

Summary: DNA glycosylase/lyases initiate the repair of damaged nucleobases in the genome by catalyzing excision of aberrant nucleobases and nicking of the lesion-containing DNA strand. Nearly all of these proteins have the unusual property of remaining tightly bound in vitro to the end products of the reaction cascade. We have taken advantage of this property to crystallize and structurally characterize the end product resulting from complete DNA processing by a catalytically active mutant form of human 8-oxoguanine DNA glycosylase (D268E hOgg1). The resulting structure is consistent with the currently accepted catalytic mechanism for the protein. Unexpectedly, however, soaking of a nucleobase analog into the crystals results in religation of the DNA backbone in situ. [Copyright &y& Elsevier]

We have constructed line-by-line fluorescence models for the ro-vibrational bands of the B–X system of sulfur dimers (S2). For the first time the detailed rotational lines of the bands are clearly resolved in the high-resolution echelle spectra of Comet Hyakutake (C/1996 B2), which were obtained at the Kitt Peak 4-m telescope on 26.4 March 1996 (UT). In order to construct satisfactory band models of the B–X system, we first compared the models to laboratory spectra available in literature, and then compared the models including Swings effects to the high-resolution spectra of Hyakutake. From the model fits, we derived a rotational temperature of 70±10 K, which should represent a temperature of a coma region close to the nucleus, where most of the S2 emissions originate. We present previously proposed scenarios for the origin of S2 in cometary comae, and compare them with our spectral analysis. [Copyright &y& Elsevier]

Mounting evidence suggests that CCL2 (MCP-1) and its hematopoietic cell receptor CC chemokine receptor 2 (CCR2) are involved in inflammatory disorders of the lung. In animal models of allergic asthma, idiopathic pulmonary fibrosis (IPF), and bronchiolitis obliterans syndrome (BOS), CCL2 expression and protein production are increased and the disease process is attenuated by CCL2 immunoneutralization. Mechanisms by which CCL2 may be acting include recruitment of regulatory and effector leukocytes; stimulation of histamine or leukotriene release from mast cells or basophils; induction of fibroblast production of transforming growth factor-β (TGF-β) and procollagen; and enhancement of Th2 polarization. Recently, polymorphism for CCL2 has been described with increased cytokine-induced release of CCL2 by monocytes and increased risk of allergic asthma. These studies identify potentially important roles for CCL2 in these lung inflammatory disorders. While CCL2 inhibition in patients with acute respiratory distress syndrome (ARDS) may be hazardous by interfering with defense against bacteremia, future studies are needed to determine if CCL2/CCR2 antagonism will offer breakthrough therapy for patients with allergic asthma, IPF, or BOS, and to confirm the hypothesis that CCL2 polymorphism places patients at greater risk for these disorders. [ABSTRACT FROM AUTHOR]

Members of the HhH-GPD superfamily of DNA glycosylases are responsible for the recognition and removal of damaged nucleobases from DNA. The hallmark of these proteins is a motif comprising a helix-hairpin-helix followed by a Gly/Pro-rich loop and terminating in an invariant, catalytically essential aspartic acid residue. In this study, we have probed the role of this Asp in human 8-oxoguanine DNA glycosylase (hOgg1) by mutating it to Asn (D268N), Glu (D268E), and Gln (D268Q). We show that this aspartate plays a dual role, acting both as an N-terminal α-helix cap and as a critical residue for catalysis of both base excision and DNA strand cleavage by hOgg1. Mutation of this residue to asparagine, another helix-capping residue, preserves stability of the protein while drastically reducing enzymatic activity. A crystal structure of this mutant is the first to reveal the active site nucleophile Lys249 in the presence of lesion-containing DNA; this structure offers a tantalizing suggestion that base excision may occur by cleavage of the glycosidic bond and then attachment of Lys249. Mutation of the aspartic acid to glutamine and glutamic acid destabilizes the protein fold to a significant extent but, surprisingly, preserves catalytic activity. Crystal structures of these mutants complexed with an unreactive abasic site in DNA reveal these residues to adopt a sterically disfavored helix-capping conformation. [ABSTRACT FROM AUTHOR]

Interleukin-12 (IL-12), consisting of p40 and p35 subunits, produces both p70 heterodimer and free p40. p70 is essential for the induction of T-helper 1 (Th1) and cytotoxic T-cell (CTL) immunity, whereas p40 inhibits p70mediated function. Here, we found that mutations introduced into N-glycosylation sites (N220 of murine p40 and N222 of human p40) reduced secretion of p40 but not p70. Co-immunization of N220 mutant mlL-12 gene with hepatitis C virus (HCV) E2 DNA significantly enhanced long-term E2-specific CD8[sup +] T-cell response and protection against tumor challenge compared with that of wild type. Our results indicate that the ratio of p70 to p40 is important for generating sustained long-term cell-mediated immunity. Thus, the mutant IL-12 could be utilized for the development of DNA vaccines as an adjuvant for the generation of long-term memory T-cell responses. [ABSTRACT FROM AUTHOR]

Provides a mechanistic insight into the inactivation of the catalytic enzyme carboxypeptidase A using the prototypical zinc-containing proteolytic enzyme alpha-benzyl-2-oxo-1,3-oxazolidine-4-acetic acid as inactivator of the catalytic enzyme. Synthesis of the four possible stereoisomers of the inhibitor; Inhibitory mechanism; Ring cleavage formation via nucleophilic attack at the 2-position.

Recent advances in cryo-electron microscopy (cryo-EM) have facilitated the high-resolution structural determination of macromolecular complexes in their native states, providing valuable insights into their dynamic behaviors. However, insufficient understanding or experience with the cryo-EM image processing parameters can result in the loss of biological meaning. In this paper, we investigate the dihydrolipoyl acetyltransferase (E2) inner core complex of the pyruvate dehydrogenase complex (PDC) and reconstruct the 3D maps using five different symmetry parameters. The results demonstrate that the reconstructions yield structurally identical 3D models even at a near-atomic structure. This finding underscores a crucial message for researchers engaging in single-particle analysis (SPA) with relatively user-friendly and convenient image processing software. This approach helps reduce the risk of missing critical biological details, such as the dynamic properties of macromolecules. [ABSTRACT FROM AUTHOR]