Muscle metastasis in a patient with epidermoid carcinoma of the lung

Diagnosis of vertically acquired human immunodeficiency virus (HIV) infection is often difficult because of transplacentally acquired maternal antibodies. The polymerase chain reaction (PCR) test is commercially available and has high sensitivity and specificity. To evaluate the usefulness of PCR testing in the early diagnosis of perinatally acquired HIV infection, we reviewed records of 122 children having follow-up in the Northeast Florida Pediatric AIDS Program. Seventy-two children were excluded for various reasons. Of the remaining 50 children, 37 had PCR testing. In 5 children, the initial PCR test was done at > 18 months of age. Results of PCR testing were positive in 8 of 13 (62%) at birth, 12 of 18 (67%) by 1 month of age, 18 of 23 (78%) by 2 months of age, and 20 of 24 (83%) by 3 months of age. In 24 of 27 (85%), results were positive by the time the children reached 4 months of age. Our data suggest that the PCR test is a useful tool for early diagnosis of vertically transmitted HIV infection.     

Fiber diffraction study of spicules from marine sponges

A synchrotron radiation fiber diffraction structural study of the axial filament of siliceous spicules from two species of marine sponges (the Demosponge Geodia cydonium and the Hexactinellid Scolymastra joubini) was carried out. The sharpness of the spots in the diffraction patterns indicated that the protein units in the filament of both samples were highly organized. A possible explanation is that the arrangement of the protein units is similar to that of the pores in highly ordered siliceous mesoporous materials. Nevertheless, the diffraction patterns are quite different for the two types of spicules. The pattern of G. cydonium is consistent with a regular 2D hexagonal lattice of protein units in the direction perpendicular to the spicule axis, with a repeating distance of 5.8 nm; the units are linked to form fibers along the axis. The pattern of S. joubini indicates the presence of two different 2D lattices in which the repeating protein units are inclined by +50 degrees and -50 degrees with respect to the elongation axis; the distance between the units increases to 8.4 nm. This 2D model is consistent with hexagonal packing of spirally oriented cylindrical protein units elongated along the filament axis.     

Surface channel MESFETs on hydrogenated diamond

Metal–semiconductor field effect transistors (MESFETs) based on hydrogen terminated diamond were fabricated according to different layouts. Aluminum gates were used on single crystal and low-roughness polycrystalline diamond substrates while gold was used for ohmic contacts. Hydrogen terminated layers were deeply investigated by means of Hall bars and transfer length structures. Room temperature Hall and field effect mobility values in excess of 100 cm2 V?1 s?1 were measured on commercial and single crystal epitaxial growth (100) plates by using the same hydrogenation process. Hydrogen induced two-dimensional hole gas resulted in sheet resistances essentially stable and repeatable depending on the substrate quality. Self-aligned 400 nm gate length FETs on single crystal substrates showed current density and transconductance values>100 mA mm?1 and >40 mS mm?1, respectively. Devices with gate length LG=200 nm showed fMax=26.4 GHz and fT=13.2 GHz whereas those fabricated on polycrystalline diamond, with the same gate geometry, exceeded fMax=23 GHz and fT=7 GHz. This work focused on the optimization of a self-aligned gate structure with respect to the fixed drain-to-source structure with which we observed higher frequency values; the new structure resulted in improvement of DC characteristics, better impedance matching and a reduction in the fMax/fT ratio.     

The interleukin-1 genotype as a severity factor in adult periodontal disease

OBJECTIVE: To determine whether it is possible to predict the presence of bladder outlet obstruction (BOO) by non-invasive clinical variables in patients with lower urinary tract symptoms (LUTS) suggestive of BOO. PATIENTS AND METHODS: Patients with LUTS suggestive of BOO were entered into a prospective protocol evaluating the International Prostate Symptom Score (IPSS), prostate size, non-invasive uroflow, post-void residual urine volume (PVR) and a pressure flow study. Only patients with a maximum flow rate (Qmax) of < or = 15 mL/s and an IPSS > or = 7 were included. The study comprised 253 patients; the degree of obstruction was correlated to several non-invasive clinical variables. Subsequently nomograms were developed by multiple logistic regression analysis to obtain the probability of BOO in patients with LUTS. RESULTS: Prostate volume, Qmax, PVR and voided volume correlated significantly with the degree of BOO rated according to the linear passive urethral resistance relation (linPURR). In contrast, there was no such correlation for the IPSS and the quality-of-life question of the IPSS. The percentage of patients with BOO defined by a linPURR of 3-6 decreased from 85% in those with a Qmax of 0-5 mL/s to 60% (Qmax 6-10 mL/s) and 44% (Qmax 11-15 mL/s). In parallel, the percentage of patients with BOO increased from 53% of those with a prostate volume of < or = 50 mL, to 79% of those with prostates of 51-100 mL and 75% of those > 100 mL. Based on Qmax, PVR and prostate volume, nomograms were established by multiple logistic regression analysis for the probability of BOO in patients with LUTS. CONCLUSION: The nomograms presented herein should help the clinician to identify patients with LUTS who should undergo pressure flow studies before surgical intervention to detect the presence of obstruction and in whom these studies can be safely spared.     

Genetic variations in cytokine expression: a risk factor for severity of adult periodontitis

Periodontitis is a collection of chronic inflammatory diseases that are caused by specific bacteria. The bacteria activate inflammatory mechanisms in the periodontal tissues that destroy collagen and bone that support the teeth. Although bacteria are essential for the initiation of periodontitis, the quantity and types of bacteria have not been sufficient to explain the differences in disease severity. In recent years, it has become evident that for many common chronic diseases, there are modifying factors that do not cause the disease but rather amplify some disease mechanisms to make the clinical condition more severe. There are now data to suggest that a few factors which amplify the inflammatory process make people susceptible to an increased severity of periodontitis. Studies of untreated disease in Sri Lanka identified 3 patterns of disease progression. Studies in twins suggested that part of the clinical characteristics of periodontitis may be explained by genetic factors, but previous attempts to identify genetic markers for periodontitis have been unsuccessful Some genetic variations (polymorphisms) are commonly found in our population and represent a mechanism by which individuals may exhibit variations within the range of what is considered biologically normal. Since certain cytokines are key regulators of the inflammatory response and are important in periodontitis, we investigated the relationship between genetic variations associated with cytokine production and periodontitis severity. There are several polymorphisms in the cluster of genes that influence IL-1 biological activity. In recent clinical trials, two of these polymorphisms, when found together, have been associated with a significant increase in the risk for severe generalized periodontitis. Genetic association with periodontitis was evident only when smokers were excluded from the analysis, confirming the importance of smoking, and suggesting that both smoking and the IL- I genotype are independent factors in severe periodontitis. It is notable that 1 polymorphism associated with severe periodontitis in our study is also known to correlate with a 2- to 4-fold increase in IL-1 beta production. These findings are consistent with the current model of how genetic factors influence common chronic diseases. If we apply this model to periodontitis, it would involve the following: 1) a disease-initiating factor that would undoubtedly be specific bacteria such as Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans. and Bacteroides forsythus: and 2) modifiers of disease mechanisms that account for the clinical severity, including smoking, the IL-I genotype, certain systemic diseases, and psychosocial stress. The association of the IL-I genotype with severe periodontitis is consistent with several lines of periodontal research. Several studies have suggested there is a substantial genetic influence in periodontal disease. Although specific genetic markers have been identified in the uncommon juvenile forms of periodontitis, previous studies of specific genetic markers in adults with periodontitis have not been encouraging. Many investigators have, however, demonstrated a role for IL-1 in the initiation and progression of periodontitis. For example, IL-1 activates the degradation of the extracellular matrix and bone of the periodontal tissues, and elevated tissue or gingival fluid levels of IL-1 beta have been repeatedly associated with periodontitis. In addition, IL-1 is a strong enhancer of tissue levels of PGE2 and TNF-alpha. The association of severe periodontitis with smoking and the IL-1 genotype suggest a role for these factors in the pathogenesis of periodontitis. The finding that host modifying factors are associated with severe periodontitis suggest a biological mechanism by which some individuals, if challenged by bacterial accumulations, may have a more vigorous immunoinflammatory response, leading to more severe clinical disease. (ABSTRACT     

Elucidating the Impact of Mg Substitution on the Properties of NASICON-Na3+yV2−yMgy(PO4)3 Cathodes

Vanadium multiredox-based NASICON-Na_zV_2−yM_y(PO₄)₃ (3 ≤ z ≤ 4; M = Al³⁺, Cr³⁺, and Mn²⁺) cathodes are particularly attractive for Na-ion battery applications due to their high Na insertion voltage (>3.5 V vs Na⁺/Na⁰), reversible storage capacity (≈150 mA h g⁻¹), and rate performance. However, their practical application is hindered by rapid capacity fade due to bulk structural rearrangements at high potentials involving complex redox and local structural changes. To decouple these factors, a series of Mg²⁺-substituted Na_3+yV_2−yMg_y(PO₄)₃ (0 ≤ y ≤ 1) cathodes is studied for which the only redox-active species is vanadium. While X-ray diffraction (XRD) confirms the formation of solid solutions between the y = 0 and 1 end members, X-ray absorption spectroscopy and solid-state nuclear magnetic resonance reveal a complex evolution of the local structure upon progressive Mg²⁺ substitution for V³⁺. Concurrently, the intercalation voltage rises from 3.35 to 3.45 V, due to increasingly more ionic V O bonds, and the sodium (de)intercalation mechanism transitions from a two-phase for y ≤ 0.5 to a solid solution process for y ≥ 0.5, as confirmed by in operando XRD, while Na-ion diffusion kinetics follow a nonlinear trend across the compositional series.     

Study of the Coupling of Terahertz Radiation to Heterostructure Transistors with a Free Electron Laser Source

High electron mobility transistors can work as room-temperature direct detectors of radiation at frequency much higher than their cutoff frequency. Here, we present a tool based on a Free Electron Laser source to study the detection mechanism and the coupling of the high frequency signal into the transistor channel. We performed a mapping over a wide area of the coupling of 0.15 THz radiation to an AlGaN/GaN transistors with cut-off frequency of 30 GHz. Local, polarization-dependent irradiation allowed us to selectively couple the signal to the channel either directly or through individual transistor bias lines, in order to study the nonlinear properties of the transistor channel. Our results indicate that HEMT technology can be used to design a millimeter-wave focal plane array with integrated planar antennas and readout electronics.     

RF power performance evaluation of surface channel diamond MESFETs

We experimentally investigate the large-signal radio frequency performances of surface-channel p-type diamond MESFETs fabricated on hydrogenated polycrystalline diamond. The devices under examination have a coplanar layout with two gate fingers, total gate periphery of 100 μm; in DC they exhibit a hole accumulation behavior with threshold voltage V_t ≈ 0-0.5 V and maximum drain current density of 120 mA/mm. The best small-signal radio frequency performances (maximum cutoff or transition frequency f_T and oscillation frequency f_max) were obtained close to the threshold and were of the order of 6 and 15 GHz, respectively. The power radio frequency response was characterized by driving the devices in class A at an operating frequency of 2 GHz and identifying through the active load-pull technique the optimum load for maximum power added efficiency. A power gain in linearity of 8 dB and an output power of approximately 0.2 W/mm with 22% power added efficiency were obtained on the optimum load impedance at a bias point V_DS = −14 V, V_GS = −1 V. To the best of our knowledge, these are the first large signal measurements ever reported for surface MESFET on polycrystalline diamond, and show the potential of such technology for the development of microwave power devices.     

Near-Infrared 810 nm Light Affects Porifera Chondrosia reniformis (Nardo, 1847) Regeneration: Molecular Implications and Evolutionary Considerations of Photobiomodulation–Animal Cell Interaction

Chemotrophic choice as a metabolic source of energy has characterised animal cell evolution. However, light interactions with animal cell photoacceptors that are able to increase energetic metabolism (photo-biomodulation (PBM)) have been previously described. In the present study, we cut three specimens of Chondrosia reniformis into four equal parts (12 fragments), and we irradiated the regenerating edge of six fragments with the previously characterised 810 nm near-infrared light, delivered at 1 W, 60 J/cm², 1 W/cm², and 60 J in a continuous-wave mode for 60 s through a flat-top hand-piece with a rounded spot-size area of 1 cm². Six fragments were irradiated with 0 W for 60 s as the controls. We performed irradiation at the time 0 h and every 24 h for a total of five administrations. We monitored the regeneration process for five days (120 h) in aquaria by examining the macroscopic and histological changes. We analysed the gene expression profile of the inflammatory processes, apoptosis, heat stress, growth factors, and collagen production and determined oxidative stress enzyme activity and the total prokaryotic symbiont content. PBM sped up C. reniformis regeneration when compared to the controls. Particularly, transforming growth factor TGF3 and TGF6 upregulation during the early phase of regeneration and TGF5 upregulation 120 h postinjury in the irradiated samples supports the positive effect of PBM in sponge tissue recovery. Conversely, the expression of TGF4, a sponge fibroblast growth factor homologue, was not affected by irradiation, indicating that multiple, independent pathways regulate the TGF genes. The results are consistent with our previous data on a wide range of organisms and humans, suggesting that PBM interaction with primary and secondary cell targets has been conserved through the evolution of life forms.