Search

Background: Bacteria in low abundance represent the majority of Earth’s biodiversity and perform vital ecological functions, but little is known about their biogeography nor the ecological processes that drive their community assembly in terrestrial ecosystems. Here, we investigated the community compositions and phylogenies of rare (relative abundance < 0.1%) and abundant (> 1%) soil bacteria along a transect containing three alpine grassland types (meadow, steppe, and desert) on the Tibetan Plateau. Results: Our results revealed similar biogeographical patterns of rare and abundant bacteria, with their community compositions and phylogenies shifting gradually along the transect. The similar patterns, however, were driven by contrasting community assembly processes, with rare subcommunity being more heavily influenced by stochasticity (72%) than abundant (57%). The composition of abundant subcommunity (80%) was better explained by local (including soil and vegetation factors), geospatial and climatic factors than that of rare subcommunity (41%), while the phylogeny of the rare one (36%) was better explained than that of the abundant one (29%). Variation partitioning analysis indicated that pure local factors consistently explained a higher proportion of the community composition than geospatial factors in both rare (12.3% and 8.7%, respectively) and abundant bacteria (18.3% and 14.1%, respectively). In contrast, the phylogeny of rare subcommunity was explained by local and geospatial factors equally (11.5% and 11.9%, respectively), while that of abundant subcommunity was more explained by geospatial (22.1%) than local factors (11.3%). Furthermore, our results revealed a tighter connection between the community phylogeny and composition in rare than in abundant bacteria. Conclusions: Our results revealed consistent biogeographical patterns of rare and abundant bacteria in grassland soils, but their assembly processes were distinct. We further demonstrated that rare subcommunity was less predictable than the abundant subcommunity by environmental and geospatial factors. Rare and abundant bacteria responded differentially to factors, which was attributed to the distinct life strategies. Our study provides novel insights into the assembly processes and biographical patterns of rare and abundant bacteria in terrestrial ecosystems.

The number of social contacts of mammals is positively correlated with the diversity of their gut microbes. There is some evidence that sociality also affects microbes in the respiratory tract. We tested whether the airway microbiota of cetacean species differ depending on the whales' level of sociality. We sampled the blow of blue (Balaenoptera musculus), grey (Eschrichtius robustus), humpback (Megaptera novaeangliae) and long-finned pilot whales (PWs) (Globicephala melas) and analysed the blow microbiota by barcode tag sequencing targeting the V4 region of the bacterial 16S rRNA gene. Humpback whales (HWs) show higher levels of sociality than blue (BW) and grey (GW), while PWs are the most gregarious among the four species. The blow samples of the HWs showed the highest richness and diversity. HWs were also the only species with a species-specific clustering of their microbial community composition and a relatively large number of core taxa. Therefore, we conclude that it cannot be sociality alone shaping the diversity and composition of airway microbiota. We suggest the whale species' lung volume and size of the plume of exhaled air as an additional factor impacting the transmission potential of blow microbiota from one individual whale to another.

Resistive switching (RS) devices are metal/insulator/metal (MIM) cells that can change their electrical resistance when electrical stimuli are applied between the electrodes, and they can be used to store and compute data. Planar crossbar arrays of RS devices can offer a high integration density (10

This brief report describes the SARS‐CoV‐2 vaccination program at our pediatric oncology unit. Adopting Italian regulations, patients treated for cancer within the previous 6 months were offered vaccination with the Pfizer‐BioNtech vaccine if aged ≥16 years, and with the Pfizer‐BioNtech or Moderna vaccine if aged ≥18 years. From March 24 to April 28, 2021, 80/89 adolescent and young adult patients enrolled were vaccinated, while nine refused the vaccine due to fear of side effects, disbelief regarding the pandemic, or lack of trust in the scientific community. The refusal rate in our cohort was lower than in the Italian general population.

Apomictic grasses predominate among tropical forages, and specific breeding techniques are needed for their genetic improvement. The objectives were to: 1- generate hybrids by crossing tetraploid sexual and apomictic Paspalum simplex genotypes, 2- develop a technique based on molecular markers for early identification of apomictic hybrids, and 3- determine the relationship between mode of reproduction and performance of hybrids. Crosses were made between two induced sexual and seven apomictic tetraploid plants. Identification of apomictic hybrids during seedling stage was performed using a marker linked to apomixis, and by flow cytometric seed analysis (FCSA). Hybrids were evaluated under field conditions for plant diameter and height, initial regrowth, and seasonal regrowth during two consecutive growing seasons. Sexual tetraploid plants used as female parents behaved as allogamous since 95% of the progeny had male-specific markers. The ratio between apomictic and sexual hybrids differed among crosses from 1:8.7 and 1:0.6 among crosses, with a mean of 1:2.4. There was a 96% coincidence between the use of the apomixis?linked marker and FCSA. A technique based on the use of an early DNA isolation and the amplification of a molecular marker linked to apomixis was developed. We found no overall difference between apomictic and sexual hybrids for the evaluated traits, except for fall regrowth in the first year, for which apomictic hybrids were superior. Generation of large tetraploid hybrid progenies is possible in P. simplex. Segregation for mode of reproduction depends on parents involved. Agronomic performance is not related to reproductive mode among tetraploid hybrids. Fil: Brugnoli, Elsa Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Martínez, Eric Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Ferrari Usandizaga, Silvana Consuelo. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Zilli, Alex Leonel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Urbani, Mario Hugo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina Fil: Acuña, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentina

Background Extra-appendicular neuroendocrine tumors (NETs) are very rare tumors. While diagnostic and therapeutic guidelines are well established for adults, data on children and adolescents are lacking. Patients and methods Patients with a diagnosis of extra-appendicular NET registered on the Tumori Rari in Eta Pediatrica - Rare Tumors in Pediatric Age (TREP) from 2000 to 2020 were analyzed. Clinical characteristics including patients' presentation, tumor features, treatment, and outcome were reviewed. Results Twenty-seven patients with extra-appendicular NET registered on TREP with a median age of 173 months. The primary site was the pancreas (12) or bronchi (10) in the majority of cases. Other primary sites included the thymus, Meckel's diverticulum, and liver. Thirteen (48%) of tumors extended beyond the organ of origin: four invaded neighboring organs and/or regional nodes and nine involved distant metastases. The 3-year event-free survival (EFS) for those with localized disease was superior to those with metastatic disease (66.6% 95% CI 5-95% vs 33% 95% CI 5-68%, respectively; P = .005). A complete resection was feasible in 17 patients. The 3-year EFS in these patients was superior to those with no or incomplete resection (R0 vs R1/R2, respectively; P = .007). Overall, 16 children had no evidence of disease at follow-up, and one is alive with disease; five died, and five were lost to follow-up. Conclusions Data from our experience demonstrated a wide heterogeneity of presentation and outcome of these tumors. Localized disease and complete surgical resection were the main prognostic factors of good outcome. Other therapies may have a role in prolonging survival in metastatic disease.

The study reports the treatment feasibility, and secondly efficacy, of a novel chemotherapy regimen, which adds vinorelbine to the ifosfamide-vincristine-actinomycin-D combination (VIVA regimen), used in four patients with high-risk rhabdomyosarcoma. All patients received nine cycles of the VIVA regimen followed by maintenance chemotherapy with vinorelbine and cyclophosphamide. All patients experienced significant hematological toxicity, but no other major complications (in particular neurotoxicity) or required treatment dose modifications. We observed a major response after three cycles in all patients, and they remained alive after a median follow up of 11 months from diagnosis.

Background and objectives The primary treatment for locally advanced cases of cervical cancer is chemoradiation followed by high-dose brachytherapy. When this treatment fails, pelvic exenteration (PE) is an option in some cases. This study aimed to develop recommendations for the best management of patients with cervical cancer undergoing salvage PE. Methods A questionnaire was administered to all members of the Brazilian Society of Surgical Oncology. Of them, 68 surgeons participated in the study and were divided into 10 working groups. A literature review of studies retrieved from the National Library of Medicine database was carried out on topics chosen by the participants. These topics were indications for curative and palliative PE, preoperative and intraoperative evaluation of tumor resectability, access routes and surgical techniques, PE classification, urinary, vaginal, intestinal, and pelvic floor reconstructions, and postoperative follow-up. To define the level of evidence and strength of each recommendation, an adapted version of the Infectious Diseases Society of America Health Service rating system was used. Results Most conducts and management strategies reviewed were strongly recommended by the participants. Conclusions Guidelines outlining strategies for PE in the treatment of persistent or relapsed cervical cancer were developed and are based on the best evidence available in the literature.

Primarily, to compare the behavior of human mesenchymal stem cells (MSCs) derived from bone marrow (hBMSCs) and adipose tissue (hADSCs) in an osteoarthritic (OA) microenvironment; secondly, to investigate the reaction of these cell types in two alternative in vitro culture systems, obtained by using TNFα and/or IL1β as inflammation mediators, or by using synovial fluid harvested by OA patients (OSF) to simulate the complex inflamed knee microenvironment. 3D micromass cultures of hBMSCs or hADSCs were grown in chondrogenic medium (CTR), in the presence of TNFα and/or IL1β, or synovial fluid from OA patients. After 1 month of culture, the chondrogenic differentiation of micromasses was evaluated by gene expression, matrix composition, and organization. Both hMSCs types formed mature micromasses in CTR, but a better response of hADSCs to the inflammatory environment was documented by micromass area and Bern score evaluations. The addition of OSF elicited a milder reaction than with TNFα and/or IL1β by both cell types, probably due to the presence of both catabolic and protective factors. In particular, SOX9 and ACAN gene expression and GAG synthesis were more abundant in hADSCs than hBMSCs when cultured in OSF. The expression of MMP1 was increased for both hMSCs in inflammatory conditions, but in particular by hBMSCs. hADSCs showed an increased chondrogenic potential in inflammatory culture systems, suggesting a better response of hADSCs in the OA environment, thus underlining the importance of appropriate in vitro models to study MSCs and potential advantages of using these cells for future clinical applications. J. Cell. Physiol. 232: 1478-1488, 2017. © 2016 Wiley Periodicals, Inc.

Landscape heterogeneity impacts community assembly in animals and plants, but it is not clear if this ecological concept extends to microbes. To examine this question, we chose to investigate polar soil environments from the Antarctic and Arctic, where microbes often form the major component of biomass. We examined soil environments that ranged in connectivity from relatively well-connected slopes to patchy, fragmented landforms that comprised isolated frost boils. We found landscape connectedness to have a significant correlation with microbial community structure and connectivity, as measured by co-occurrence networks. Soils from within fragmented landforms appeared to exhibit less local environmental heterogeneity, harboured more similar communities, but fewer biological associations than connected landforms. This effect was observed at both poles, despite the geographical distances and ecological differences between them. We suggest that microbial communities inhabiting well-connected landscape elements respond consistently to regional-scale gradients in biotic and edaphic factors. Conversely, the repeated freeze thaw cycles that characterize fragmented landscapes create barriers within the landscape and act to homogenize the soil environment within individual frost boils and consequently the microbial communities. We propose that lower microbial connectivity in the fragmented landforms is a function of smaller patch size and continual disturbances following soil mixing.

Graphene and related materials (GRMs) are promising candidates for the fabrication of resistive random access memories (RRAM). Here, we analyze, classify and evaluate this emerging field, and summarize the performance of the RRAM prototypes using GRMs. Graphene oxide, amorphous carbon films, transition metal dichalcogenides, hexagonal boron nitride and black phosphorous can be used as resistive switching media, in which the switching can be governed either by the migration of intrinsic species or penetration of metallic ions from adjacent layers. Graphene can be used as electrode to provide flexibility and transparency, as well as an interface layer between the electrode and dielectric to block atomic diffusion, reduce power consumption, suppress surface effects, limit the number of conductive filaments in the dielectric, and improve device integration. GRMs-based RRAMs fit some non-volatile memory technological requirements like low operating voltages 10 years, endurance >109 cycles and power consumption ~10 pJ/transition still remain a challenge. More technology-oriented studies including reliability and variability analyses may lead to the development of GRMs-based RRAMs with realistic possibilities of commercialization.

Objective To determine cutoff values for defining the states of inactive disease (ID), low disease activity (LDA; or minimal disease activity), moderate disease activity (MDA), and high disease activity (HDA) using the clinical (3-variable) Juvenile Arthritis Disease Activity Score (cJADAS). Methods For selection of cutoffs, data from a clinical database including 609 children with juvenile idiopathic arthritis (JIA) were used. Optimal cutoffs were determined against external criteria by calculating the 75th and 90th percentile (for ID and LDA) and 10th and 25th percentile (for HDA) of cumulative score distribution and through receiver operating characteristic curve analysis. External criteria included definitions for ID and LDA cutoffs and therapeutic decisions for HDA cutoffs. MDA cutoffs were set at the score interval in-between LDA and HDA cutoffs. Crossvalidation was performed using 2 JIA patient samples (n = 485) and was based on assessment of construct and discriminant validity. Results The selected cutoffs were as follows: ≤1 for ID in both oligoarthritis and polyarthritis; ≤1.5 and ≤2.5 for LDA in oligoarthritis and polyarthritis, respectively; 1.51–4 and 2.51–8.5 for MDA in oligoarthritis and polyarthritis, respectively; and >4 and >8.5 for HDA in oligoarthritis and polyarthritis, respectively. In crossvalidation analyses, the cutoffs showed a strong ability to discriminate between disease activity states defined subjectively by physicians and parents, levels of pain, and presence/absence of functional impairment and disease damage. Conclusion Cutoff values for classifying various disease states in nonsystemic JIA using the cJADAS were developed. The cutoffs revealed good measurement characteristics in crossvalidation analyses and are suited for application in clinical practice and research.

Graphene–polymer composites play an increasing role in photonic and optoelectronic applications, from ultrafast pulse generation to solar cells. The fabrication of an optical quality surfactant-free graphene-styrene methyl methacrylate composite, stable to large humidity and temperature ranges is reported. The composite is tailored for photonic applications showing wavelength-independent linear absorption in the visible and near-infrared. When tested in a mode-locked laser, it allows the generation of stable ≈ 326 fs mode-locked pulses at 1550 nm, unperturbed by environmental conditions. The composite continues to operate as a saturable absorber even under complete water immersion at 60 °C. This confi rms its stability against high- temperature and humidity.

Toxin production during cyanobacterial blooms poses a significant public health threat in water bodies globally and requires the development of effective bloom management strategies. Previously, synthesis of the hepatotoxin microcystin has been proposed to be regulated by iron availability, but the contribution of the toxin to the adaptation of cyanobacteria to environmental stresses, such as changing light intensity and nutrient limitation, remains unclear. The aim of this study was to compare the iron stress response in toxic and non-toxic strains of Microcystis aeruginosa subjected to moderate and severe iron limitation. The transcription of a number of genes involved in iron uptake, oxidative stress response, toxin synthesis and transcriptional control of these processes was accessed by quantitative real-time PCR (qRT-PCR). The process of adaptation of M. aeruginosa to iron stress was found to be highly dynamic and strain-specific. Toxin production in PCC 7806 increased in an iron-dependent manner and appeared to be regulated by FurA. The inability to produce microcystin, either due to natural mutations in the mcy gene cluster or due to insertional inactivation of mcyH, affected the remodelling of the photosynthetic machinery in iron-stressed cells, the transport of Fe(II) and transcription of the Fur family of transcriptional regulators. The presence of the toxin appears to give an advantage to microcystin-producing cyanobacteria in the early stages of exposure to severe iron stress and may protect the cell from reactive oxygen species-induced damage.

Nanoactuators are a key component for developing nanomachinery. Here, an electrically driven device yielding actuation stresses exceeding 1 MPa withintegrated optical readout is demonstrated. 10 nm thick Al2 O3 electrolyte films are sandwiched between graphene and Au electrodes. These allow reversible room-temperature solid-state redox reactions, producing Al metal and O2 gas in a memristive-type switching device. The resulting high-pressure oxygen micro-fuel reservoirs are encapsulated under the graphene, swelling to heights of up to 1 µm, which can be dynamically tracked by plasmonic rulers. Unlike standard memristors where the memristive redox reaction occurs in single or few conductive filaments, the mechanical deformation forces the creation of new filaments over the whole area of the inflated film. The resulting on-off resistance ratios reach 108 in some cycles. The synchronization of nanoactuation and memristive switching in these devices is compatible with large-scale fabrication and has potential for precise and electrically monitored actuation technology.

Graphene nanoribbons (GNRs) are the counterpart of nanotubes in graphene nanoelectronics. The search for a cheap, parallel, and deterministic technique for practical implementation of these structures is still open. Nanowire lithography (NWL) consists in using nanowires (NWs) as etch masks to transfer their one-dimensional morphology to an underlying substrate. Here, we show that oxidized silicon NWs (SiNWs) are a simple and compatible system to implement NWL on graphene. The SiNWs morphology is transferred onto a graphene flake by a low-power O 2 plasma in a deep-reactive-ion-etcher. The process leads to conformal GNRs with diameter comparable to the overlaying NW lateral dimensions. The diameter can be further reduced by multiple O 2 etching steps. Field-effect measurements show the transition to a semiconductor for low diameters.

Polymer composites are one of the most attractive near-term means to exploit the unique properties of carbon nanotubes and graphene. This is particularly true for composites aimed at electronics and photonics, where a number of promising applications have already been demonstrated. One such example is nanotube-based saturable absorbers. These can be used as all-optical switches, optical amplifier noise suppressors, or mode-lockers to generate ultrashort laser pulses. Here, we review various aspects of fabrication, characterization, device implementation and operation of nanotube-polymer composites to be used in photonic applications. We also summarize recent results on graphene-based saturable absorbers for ultrafast lasers.

We compare the electronic properties of graphene nanoribbons, with either bulk or edge substitutions, edge functionalization, or chemisorption. Chemical modifications can cause semiconductor-metal transitions, lifting of spin degeneracy, widening of bandgap, or appearance of non-dispersive impurity bands and doping.

We report characterization by absorption and photoluminescence excitation (PLE) spectroscopy of carbon nanotube solutions, which are then used for nanotube-based composite preparation. PLE shows the presence of bundles in the solution. The composite show a saturation intensity of 5 MW/cm 2 and is used in a fibre laser to generate pulses as short as 866 fs at about 1530 nm.

We investigate and compare the electronic transport in ambipolar SiNWs as a function of the metal choosen for contact deposition. The wires are grown by Au-catalyzed vapour-transport and exhibit crystalline cores about 15-20 nm in thickness. The suitability of Ti and Ni contacts on SiNWs is evaluated in terms of contact resistance and band-alignment. The beneficial effect of a rapid-thermal-annealing at mild temperatures (400 °C) is also investigated. We observe that annealed Ni contacts yield the lowest device resistance and highest ON/OFF ratio.

BACKGROUND. The Ewing sarcoma family of tumors (ESFT) is one of the most common malignant neoplasms of children and adolescents, characterized by nonrandom translocations involving the Ewing sarcoma (EWS) gene. Over the years the adoption of intensive multimodality treatment approaches has led to a gradual improvement in the survival of patients with ESFT. The prognosis is still unsatisfactory for high-risk patients, however, and novel therapeutic approaches are desirable. The aim of the study was to investigate the expression/activation of KIT, PDGFRα, and PDGFRβ receptor tyrosine kinases (RTKs) as potential therapeutic targets in ESFT. METHODS. RNA and proteins were extracted from 20 frozen ESFT specimens to ascertain the state activation of KIT, PDGFRα, and PDGFRβ. RESULTS. No mutations were found, whereas the cognate ligands were detected in all cases by polymerase chain reaction (PCR). The expression and activation of KIT, PDGFRα, and PDGFRβ were confirmed by quantitative PCR, immunohistochemistry, and immunoprecipitation and/or Western blot analysis. In particular, when compared with a protein pool obtained from normal adult tissues, PDGFRβ showed a greater protein expression and/or a stronger phosphorylation signal. CONCLUSIONS. The results are consistent with an autocrine/paracrine loop activation of the KIT, PDGFRα, and PDGFRβ receptors and suggest a rationale for the use of RTK inhibitors, either alone or in combination with chemotherapy. Cancer 2007. © 2007 American Cancer Society.

Background: Significant developments in biological applications are occurring through the incorporation of Quantum Dots (QDs) as biological labels. The demonstration of QDs unique optical properties may have important implications for the study of environmental samples, where microorganisms of interest need to be isolated away from the background debris. Methods: Flow cytometric analysis was used to determine the fluorescence intensity of oocysts after mAb staining by QDs or organic fluorophore conjugates. In addition, the level of non-specific binding to detrital particles within a control water concentrate was estimated using the optimal staining concentration determined for each mAb analyzed. Results: Under 488 nm excitation, oocysts stained with QD-conjugates exhibited significantly lower fluorescence intensity than organic conjugates. Moreover, the level of non-specific binding by QD-conjugates to detrital particles present in the water concentrate was significantly higher that of the organic conjugates. Conclusions: While QDs are noted for their superior spectral characteristics, they have been shown here to be unsuitable for conventional flow cytometric detection of Cryptosporidium. Therefore, we conclude that in their current form, QD's are severely limited for fluorescent detection of pathogens in environmental applications. © 2007 International Society for Analytical Cytology

Polar II-VI semiconductors can nucleate in complex shapes ranging from nanowires to nanoribbons, nanosaws and multipods. Here we demonstrate the deterministic and fully reproducible shape-selective growth of several morphologies of CdSe and ZnTe nanocrystals by a steady-state vapour transport process. A simple pressure-based precursor-flow shutter excludes any effects of temperature ramping, ensuring reproducible shape selectivity for each set of deposition parameters. Once thermal gradients are eliminated, we show that the transition from one nanocrystal shape to another is controlled just by the interplay of precursor impinging on the substrate (ruled by the powder temperature Tp) and sample surface kinetics (ruled by the sample temperature T s ). Furthermore, a regime is found where seeded, epitaxial growth of CdSe nanorods becomes dominant over the conventional catalyst-assisted nucleation. This allows the fabrication of vertical nanorod arrays free of any metal contamination. Seeded growth of branched and tetrapod-like nanocrystals is also possible by further optimisation of the growth parameters.

Prostate carcinoma is characterized by the silencing of pi-class glutathione S-transferase gene (GSTP1), which encodes a detoxifying enzyme. The silencing of GSTP1, due to aberrant methylation at the CpG island in the promoter/5'-UTR, occurs in the vast majority of prostate tumors and precancerous lesions. It is a pathologic marker and probably an underlying cause of oxidative damage and inflammation at tumor initiation. Inhibition of the aberrant promoter methylation could therefore be an effective mean to prevent carcinogenesis. Several isothiocyanates, including phenethyl isothiocyanate (PEITC), found naturally in cruciferous vegetables, induced growth arrest and apoptosis in prostate cancer cells in culture and xenografts. The effects of PEITC to reactivate GSTP1 were investigated. Exposure of prostate cancer LNCaP cells to PEITC inhibited the activity and level of histone deacetylases (HDACs), and induced selective histone acetylation and methylation for chromatin unfolding. Concurrently PEITC demethylated the promoter and restored the unmethylated GSTP1 in both androgen-dependent and -independent LNCaP cancer cells to the level found in normal prostatic cells, as quantified by methylation-specific PCR and pyrosequencing. The dual action of PEITC on both the DNA and chromatin was more effective than 5'-Aza-2'-deoxycytidine, sodium butyrate, or trichostatin A (TSA), and may de-repress the methyl-binding domain (MBD) on gene transcription. The PEITC-mediated cross-talk between the DNA and chromatin in demethylating and reactivating GSTP1 genes, which is critically inactivated in prostate carcinogenesis, underlines a primary mechanism of cancer chemoprevention. Consequently, new approaches could be developed, with isothiocyanates to prevent and inhibit malignancies.

Acroceras macrum is a warm-season grass used for pas-tures, and it has high nutritive value. The scarcegenetic and reproductive information about this grassis limiting its breeding for forage. The objective of thisresearch was to determine the number of genotypesand cytotypes present in a collection established inArgentina, and to estimate the diversity of this speciesbased on molecular markers, and morphological andagronomic characteristics. The number of genotypesamong forty-seven accessions was determined usingISSR markers. The identified genotypes were furthercharacterized for ploidy levels. In addition, the geneticdistances among them were estimated with ISSRmarkers. They were also propagated and planted intothe field following a randomized complete blockdesign with four replications, and a group of sixteenmorphological and agronomic variables were evalu-ated. A total of twenty-seven genotypes were identi-fied in this collection; twenty-two genotypes weretetraploid (2n = 4x = 36) and five were hexaploid(2n = 6x = 54). These two cytotypes were foundclearly separated by both genetic and phenotypic char-acteristics. Above-ground biomass, internode length,initial growth and number of spikelets per inflores-cence were the most variable traits. The high diversitypresent in this collection will allow for the initiationof a breeding programme for A. macrum. Fil: Ferrari Usandizaga, Silvana C.. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Brugnoli, Elsa Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina Fil: Weiss, Alejandra I.. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Zilli, Alex Leonel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina Fil: Schedler, M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina Fil: Pagano, E. M.. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Martínez, Eric Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina Fil: Acuña, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentina

Background The aim of the study was to assess the prevalence of hand paresthesias (HP) and their relationship with pruning activities. Methods A cross-sectional study was conducted among 537 workers pruning grapevines in the region of Champagne. All workers completed a questionnaire about nocturnal HP and musculoskeletal pain during the preceding 12-month period. Results The 12-month prevalence of nocturnal HP and hand-wrist pain were 37 and 12%, respectively. HP, predominantly affecting the dominant hand, only began during the pruning period and ended after the pruning season in 90% of cases. HP were transient in most cases, with a mean duration of symptoms of 3.3 ± 3.2 months. Risk factors associated with HP were: female gender (OR = 2.3 [1.3–3.0]), being overweight (OR = 1.6 [1.1–2.5]), payment on a piecework basis (OR = 2.0 [1.2–2.3]) and traditional blade sharpening method (OR = 1.7 [1.1–2.7]). HP were less frequent in employees who used electric pruning shears (OR = 0.5 [0.2-1.6], P = 0.09). Conclusions The development of HP, which affected a third of employees, was different from HP observed in industrial workers since most vineyard workers recovered without medical treatment after the pruning season. Am. J. Ind. Med. 40:639–645, 2001. © 2001 Wiley-Liss, Inc

L-arginine phosphate monohydrate (LAP) organic crystals were investigated by X-ray Lang topography. Selected topographs of nearly perfect seeded grown and self-nucleated crystals show that typical defects inside are grown-in and post-growth dislocations, growth sector boundaries, and microbes, while their features are presented and discussed. No structural defects associated to the presence of step bunching on the (100) surface of the crystal have been observed by X-ray topography.

Background: Cryptosporidium is an important waterborne pathogen. Detection of Cryptosporidium in concentrated water samples depends on oocyst isolation using immunomagnetic separation (IMS) and/or fluorescence-activated cell sorting (FACS), followed by confirmation using immunofluorescence staining (IFA) and fluorescence microscopy. These methods require highly trained microscopists for oocyst identification and confirmation. Analysis is hampered due to the presence of autofluorescent particles coupled with particles binding nonspecifically with the monoclonal antibodies (mAbs) used for detection. Flow cytometry (FCM) has the potential to be a more specific method for oocyst detection, but such a system would require more than one selection parameter. Methods: Various mAbs from commercial suppliers were paired with CRY104-PE and evaluated. The mAb combination that best discriminated stained oocyst from detritus was optimized and compared to Cryptosporidium detection utilizing one-color IFA/FACS. Results: A highly specific two-color assay employing the IgG1 mAb CRY104 was developed. The assay resulted in reductions, up to 20-fold, in the number of non-Cryptosporidium particles detected. The addition of a second selection parameter improved microscopic analysis times and simplified oocyst confirmation by microscopists. Conclusions: A two-color assay employing competing surface mAbs reduces the number of fluorescent particles sorted, thus improving FCM detection methods for Cryptosporidium. Cytometry 41:216 ‐222, 2000. © 2000 Wiley-Liss, Inc.

A compact electron cyclotron wave resonance (ECWR) source has been developed for the high rate deposition of hydrogenated tetrahedral amorphous carbon (ta-C:H). The ECWR provides growth rates of up to 900 A/min over a 4 diameter and an independent control of the deposition rate and ion energy. The ta-C : H was deposited using acetylene as the source gas and was characterized in terms of its sp 3 content, mass density, intrinsic stress, hydrogen content, C-H bonding, Raman spectra, optical gap, surface roughness and friction coefficient. The results obtained indicated that the film properties were maximized at an ion energy of approximately 167 eV, corresponding to an energy per daughter carbon ion of 76 eV. The relationship between the incident ion energy and film densification was also explained in terms of the subsurface implantation of carbon ions into the growing film.

The sense of olfaction in armadillos plays an important role, suggested by the great development of the nasal structures, olfactory bulbs, and related brain regions. The mammalian olfactory mucosa is a privileged site of neuronal death and regeneration during the whole life span. A detailed knowledge of its ultrastructure is convenient for gaining insight into the factors controlling those phenomena. We performed this work in species not previously studied in order to provide a firm basis for further research on those factors. No information is available on the histology and ultrastructure of the olfactory mucosa in the order Xenarthra to which armadillos belong. Samples from the endoturbinals of the armadillo Chaetophractus villosus were prepared for light and electron microscopic examination by the usual conventional means. The olfactory epithelium of Chaetophractus villosus shows the classical three types of cells: supporting cells, olfactory receptor neurons, and basal cells. The olfactory neurons and the basal cells were similar to that described in other species. Two different types of supporting cells are described. An outstanding characteristic of the supporting cells is the normal presence of abundant phagosomes, apical secretory granules, apocrine-like protrusions, and highly developed smooth endoplasmic reticulum. Apoptotic bodies are frequently found in the infranuclear cytoplasm of supporting cells. The ductular epithelium of Bowman's glands reveals secretory activity. The lamina propria shows mixed Bowman's glands. Great development of smooth endoplasmic reticulum is observed in the mucous acinar cells. Evidence for merocrine and apocrine mechanisms in the Bowman's glands is presented. The presence of apoptotic bodies and phagosomes in supporting cells suggests a participation in the cellular events induced by cell death and proliferation of the olfactory epithelium. The variety of characteristics exhibited by the supporting cells of the olfactory mucosa may contribute to a deeper understanding of their scarcely known functions.

Carbon is a very versatile element that can crystallize in the forms of diamond or graphite. There are many noncrystalline carbons, known as amorphous carbons. An amorphous carbon with a high fraction of diamond-like (sp3) bonds is named diamond-like carbon (DLC). Unlike diamond, DLC can be deposited at room temperature. Furthermore, its properties can be tuned by changing the sp3 content, the organization of the sp2 sites, and the hydrogen content. This makes DLC ideal for a variety of different applications. We review the use of ultrathin DLC films for ultrahigh-density data storage in magnetic and optical disks and ultralong beer storage in plastic bottles.

Eighteen healthy male blood donors, nine with hematocrit (Hct) of 0.40 to 0.45 (normal Hct) and nine with Hct of 0.49 to 0.52 (upper-limit Hct), were monitored by continuous-wave internal carotid Doppler sonography and hematologic tests for 28 days after blood donation, to ascertain whether and to what extent a single standard donation may modify the velocity of cerebral blood flow. The two groups had similar mean predonation values of internal carotid flow velocity (ICFV): blood donation was followed in both groups by a slight, transient decrease of ICFV at the end of phlebotomy, due to donation-induced hypovolemia, and then by an increase of ICFV lasting 7 to 10 days. Analysis of individual profiles revealed that only four of nine upper-limit and six of nine normal Hct donors displayed a positive trend (increase) in the ICFV within the first week after donation, and that it was due mainly to a rise in systolic flow velocity. Mean Hct and arterial oxygen content showed a negative trend (decrease) within the first week that was opposite to the ICFV trend. Other laboratory variables, including serum proteins and plasma fibrinogen concentration, and the iron status indicators did not change, except for serum ferritin, which also decreased within the first week after phlebotomy. It can be concluded that blood donation may result in a short-term increase of blood flow velocity that is independent of Hct predonation levels in approximately one-half of the donors.

Six nervous system drugs which inhibited vegetative reproduction of S. cerevisiae arrested also mitotic division of C. utilis, C. albicans and C. tropicalis. Chlorpromazine and chlorpheniramine which proved to be the most effective, affected respiration and cytochrome biosynthesis. Electrophoretic bands with MW congruent to 100 K were faint in silver-stained electrophoregrams of proteins from cells grown in the presence of a sub-inhibitory concentration of chlorpromazine.

Five patients with hairy cell leukemia (HCL) were studied. Peripheral blood leukocytes, rosette-forming cells (T) and non-T-cells were stained in immunofluorescence by a panel of monoclonal antibodies to investigate the phenotype of HCL cells (HCLC). In all patients HCLC showed B-lymphocyte phenotype, although they were not stained by antibodies reactive for monocytes, natural killer cells, or T-cells. However, in all instances the large majority of HCLC were unexpectedly stained with an antibody (anti-CD1a) usually detectable only in early thymocytes and on Langerhans cells. This finding was further confirmed by immunoelectron microscopy. This type of ambiguity in the lineage of HCL could imply that HCLC might arise from cells differentiated towards the B-cell lineage, still sustaining an early antigen of a different (T) lineage. These results, moreover, extend the range of the known distribution of the CD1a antigen, which could be useful in diagnosing HCL.

This case report illustrates the microscopical and ultrastructural findings obtained in a case of Abrikossoff's tumor. On the basis of the light and ultrastructural data a neural histogenesis is suggested.

In the present study the fine structures of Leu-7+-Leu-15+ and Leu-7+-Leu-15- cell subpopulations were characterized by using an immunogold-immunoperoxidase double labelling in electron microscopy. The densities of Leu-15 antigenic sites on both E rosetting (Er) and non-adherent/non-E rosetting (non-A/non-Er) Leu-15 positive cell surfaces were also evaluated by using an immunogold analysis in electron microscopy. A majority of Leu-7+ cells co-expressed the Leu-15 antigen and showed an ultrastructural pattern specific for mature natural killer (NK) cells, i.e. abundant cytoplasm with many organelles, numerous electron dense granules, and irregular outline. On the other hand, a minority of Leu-7+ cells did not express the Leu-15 antigen and showed a clearly different ultrastructural feature in comparison to Leu-7+-Leu-15+ cells. Thus, the presence of the Leu-15 antigen on Leu-7+ cell surface corresponds to ultrastructural features specific to differentiated NK cells and may represent an expression of Leu-7+ cell differentiation. An alternative hypothesis may be that Leu-7+-Leu-15+ and Leu-7+-Leu-15- cells represent distinct cell lineages within non-A/non-Er Leu-7+ cells. Finally, the results of the present study provide proof that Leu-15 antigen is more frequently represented on non-A/non-Er Leu-15+ cells than on Er Leu-15+ cells.

Verf. untersucht das Problem des Einflusses der Prandtlschen Zahl auf die turbulenten Warmeubergange in Stromungen mit hoher Geschwindigkeit fur eine beliebige Wandtemperatur. Es wird der Einflus der Prandtlschen Zahl auf den Ruckgewinnfaktor bestimmt; dann erhalt man, unter Berucksichtigung einer laminarturbulenten Ubergangsschicht, die Formeln, die die Nusseltsche Zahl ergeben und die als eine Erweiterung der Formeln von Prandtl-Taylor und von von Karman betrachtet werden konnen. Die experimentellen Ergebnisse stehen in gutem Einklang zu den rechnerischen Ergebnissen. The Author puts forth the problem of the influence of Prandtl's number on the heat transmission in a turbulent boundary layer at high speeds, when the wall-temperature distribution is arbitrarily assigned. The influence of Prandtl's number on the recovery factor is determined; then the formulas giving Nusselt's number are derived, considering the existence of a buffer zone between the laminar sub-layer and the truly turbulent layer, and which can be considered as an extention of Prandtl-Taylor's and Von Karman's formulas. The experimental results agree with the calculated ones.