We describe Bioconductor infrastructure for representing and computing on annotated genomic ranges and integrating genomic data with the statistical computing features of R and its extensions. At the ...core of the infrastructure are three packages: IRanges, GenomicRanges, and GenomicFeatures. These packages provide scalable data structures for representing annotated ranges on the genome, with special support for transcript structures, read alignments and coverage vectors. Computational facilities include efficient algorithms for overlap and nearest neighbor detection, coverage calculation and other range operations. This infrastructure directly supports more than 80 other Bioconductor packages, including those for sequence analysis, differential expression analysis and visualization.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Developments in liquid desiccant dehumidifier and regenerator are reviewed.•Working principle of various types of dehumidifier and regenerator are explained.•Performance of several flow ...configurations and desiccant materials are discussed.•Design, operating, and performance parameters are explained.•Recommendations for future research are suggested.
Liquid desiccant air conditioning systems (LDAS) are an energy-efficient and eco-friendly alternative to conventional air conditioning systems. The performance of a LDAS significantly depends on its simultaneous heat and mass transfer components, namely dehumidifier and regenerator. These components are referred to as liquid desiccant energy exchangers (LDEEs) since the working fluids (air and desiccant) exchange both heat and moisture. There has been a lot of research on LDEEs over the last two decades to improve their performance, thereby enhancing the efficiency of the LDAS. The main objective of this comprehensive review paper is to summarize the developments of LDEEs. The desiccant material, and design, operating, and performance parameters of LDEEs are explained in detail. Even though a lot of research has been done on LDEEs, they are not much utilized in the practical heating, ventilation, and air conditioning (HVAC) systems. To address this issue, future research should prioritize its focus on (i) practical problems of LDEEs such as cross contamination, and leakage and blockage of the membrane, (ii) long term performance study in the practical systems, (iii) noncorrosive and inexpensive solution, (iv) compatible material for efficient heat and mass transfer, and (v) generalized design and performance control methodology. The discussions presented in this communication will be useful to ascertain the crucial research gaps that need to be addressed by future research studies.
The ability to induce an energy band gap in bilayer graphene is an important development in graphene science and opens up potential applications in electronics and photonics. Here we report the ...emergence of permanent electronic and optical band gaps in bilayer graphene upon adsorption of π electron containing molecules. Adsorption of n- or p-type dopant molecules on one layer results in an asymmetric charge distribution between the top and bottom layers and in the formation of an energy gap. The resultant band gap scales linearly with induced carrier density though a slight asymmetry is found between n-type dopants, where the band gap varies as 47 meV/1013 cm–2, and p-type dopants where it varies as 40 meV/1013 cm–2. Decamethylcobaltocene (DMC, n-type) and 3,6-difluoro-2,5,7,7,8,8-hexacyano-quinodimethane (F2-HCNQ, p-type) are found to be the best molecules at inducing the largest electronic band gaps up to 0.15 eV. Optical adsorption transitions in the 2.8–4 μm region of the spectrum can result between states that are not Pauli blocked. Comparison is made between the band gaps calculated from adsorbate-induced electric fields and from average displacement fields found in dual gate bilayer graphene devices. A key advantage of using molecular adsorption with π electron containing molecules is that the high binding energy can induce a permanent band gap and open up possible uses of bilayer graphene in mid-infrared photonic or electronic device applications.
Two-dimensional materials are one of the most active areas of nanomaterials research. Here we report the structural stability, electronic and vibrational properties of different monolayer ...configurations of the group IV elemental materials silicene and germanene. The structure of the stable configuration is calculated and for planar and low (<1 Å) atomic buckling configurations, analysis of the electronic band structure reveals linear band dispersion giving rise to massless Dirac Fermions with a Fermi velocity about two-thirds that of graphene. Monolayer stability is shown to be directly attributed to the phonons present with the instability being driven by the out-of-plane ZA and ZO phonon modes. Long momentum relaxation lengths and high carrier mobilities are predicted for silicene and germanene based devices as carrier relaxation via phonon scattering is found to be inhibited as the electron–optical phonon coupling matrix elements are calculated to be small, being about a factor of 25 times smaller than in graphene. The consequences for phonon scattering, high energy electrical transport and integration of elemental monolayers into electronic devices are further discussed.
Future generation local communication systems will need to employ THz frequency bands capable of transferring sizable amounts of data. Current THz technology via electrical excitation is limited by ...the upper limits of device cutoff frequencies and by the lower limits of optical transitions in quantum confined structures. Current metallic THz antennas require high power to overcome scattering losses and tend to have low antenna efficiency. It is shown here via calculation and simulation that graphene can sustain electromagnetic propagation at THz frequencies via engineering the intra‐ and interband contributions to the dynamical conductivity to produce a variable surface impedance microstrip antenna with a several hundred GHz bandwidth. The optimization of a circular graphene microstrip patch antenna on silicon with an optimized return loss of −26 dB, a −10 dB bandwidth of 504 GHz, and an antenna efficiency of −3.4 dB operating at a frequency of 2 THz is reported. An improved antenna efficiency of −0.36 dB can be found at 3.5 THz but is accompanied by a lower bandwidth of about 200 GHz. Such large bandwidths and antenna efficiencies offer significant hope for graphene‐based flexible directional antennas that can be employed for future THz local device‐to‐device communications.
Graphene is shown to sustain electromagnetic wave propagation at THz frequencies and leads to ultrawide band antennas of several hundred GHz bandwidth and is a route to bridge the so‐called THz gap. Such a technology will open up the possibility of efficient data transfer at high rates for local device‐to‐device communications on flexible and conformal substrates.
The process of cement slurry curing into a solid has a direct effect on the initial state of stress in a composite concrete and steel structure. Failure models for critical infrastructure and ...wellbores could benefit from measurements of this initial stress because it greatly influences structural performance. Here, we present measurements of the initial stress state (total stress, effective stress, and pore pressure) of multiple cement formulations cured under a high-pressure of 40 MPa within a semi-rigid steel pipe. Our results show that cements cured in this restrained environment exhibit dense microstructures with low permeability (nano-Darcy), develop an anisotropic stress state greater than zero and less than the curing pressure, and undergo a staged curing process where hydration and mechanical behaviors evolve from a slurry into a pre-stressed porous medium. Both drained and undrained scenarios were investigated, revealing a feedback from the semi-rigid boundary towards improved cement performance.
Primary biliary cirrhosis Carey, Elizabeth J, MD; Ali, Ahmad H, MD; Lindor, Keith D, MD
The Lancet (British edition),
10/2015, Letnik:
386, Številka:
10003
Journal Article
Recenzirano
Summary Primary biliary cirrhosis is a chronic cholestatic liver disease characterised by destruction of small intrahepatic bile ducts, leading to fibrosis and potential cirrhosis through resulting ...complications. The serological hallmark of primary biliary cirrhosis is the antimitochondrial antibody, a highly disease-specific antibody identified in about 95% of patients with primary biliary cirrhosis. These patients usually have fatigue and pruritus, both of which occur independently of disease severity. The typical course of primary biliary cirrhosis has changed substantially with the introduöction of ursodeoxycholic acid (UDCA). Several randomised placebo-controlled studies have shown that UDCA improves transplant-free survival in primary biliary cirrhosis. However, about 40% of patients do not have a biochemical response to UDCA and would benefit from new therapies. Liver transplantation is a life-saving surgery with excellent outcomes for those with decompensated cirrhosis. Meanwhile, research on nuclear receptor hormones has led to the development of exciting new potential treatments. This Seminar will review the current understanding of the epidemiology, pathogenesis, and natural history of primary biliary cirrhosis, discuss management of the disease and its sequelae, and introduce research on new therapeutic options.
Objective
Research situated within the Developmental Origins of Health and Disease demonstrates that stressors are correlated with future mortality risk, especially if experienced frequently and ...during early periods of postnatal life. This study examines if the developmental timing and frequency of early life stressors influenced mortality risk for Indigenous Guale in Spanish Florida during the 17th century.
Materials and Methods
The present study examines internal enamel microgrowth disruptions (accentuated lines—AL) from Guale individuals (n = 52) interred at Mission Santa Catalina de Guale on St. Catherines Island, Georgia (AD 1605–1680). Teeth were thin‐sectioned and microscopically analyzed to document AL variables as predictors of age‐at‐death.
Results
Individuals with AL died earlier than those without AL. This difference, however, was not significant. Individuals who exhibit AL formed during their first year of life died on average three times earlier than those who did not. The frequency of AL and age‐at‐first‐AL are significantly correlated with age‐at‐death, and Cox hazard analyses indicates that individuals with early forming and frequent AL had increased risks of early death.
Discussion
This study emphasizes how the lived experiences of Guale children shaped demographic patterns during the 17th century. The survival of early life stressors resulted in life history trade‐offs and increased risks for early death. Mortality risks were exacerbated for individuals who experienced frequent stressors during the earliest periods of life. This underscores a role for bioarchaeology in understanding of how accumulative stress burdens during the earliest years of postnatal life may influence mortality risk.
Two-dimensional (2D) oxides have a wide variety of applications in electronics and other technologies. However, many oxides are not easy to synthesize as 2D materials through conventional methods. We ...used nontoxic eutectic gallium-based alloys as a reaction solvent and co-alloyed desired metals into the melt. On the basis of thermodynamic considerations, we predicted the composition of the self-limiting interfacial oxide. We isolated the surface oxide as a 2D layer, either on substrates or in suspension. This enabled us to produce extremely thin subnanometer layers of HfO₂, Al₂O₃, and Gd₂O₃. The liquid metal–based reaction route can be used to create 2D materials that were previously inaccessible with preexisting methods. The work introduces room-temperature liquid metals as a reaction environment for the synthesis of oxide nanomaterials with low dimensionality.
Leakage of CO2 and brine from geologic storage reservoirs along wellbores is a major risk factor to the success of geologic carbon sequestration. We conducted multiphase supercritical (sc)CO2-brine ...coreflood experiments that simulate a leakage pathway along the cement/rock interface. A composite core constructed of oil-well cement and siltstone separated by a simulated damage zone (defect) containing ground cement and siltstone was flooded with brine + scCO2 at 10 MPa and 60 °C parallel to the defect. During coinjection of scCO2, the effective brine permeability decreased from ∼200 to 90 mD due to transition to two-phase flow and then further declined to 35 mD. CO2 injection resulted in a pH drop from 11 to 4 and carbonate-undersaturated conditions in the produced brine. Microscopy revealed leaching and erosion along the defect, a carbonation front extending 5 mm into the cement, parallel to the damage zone, and no change in the dimensions of the defect. Carbonation of cement does not appear to explain the permeability drop, which is attributed to the migration and reprecipitation of alteration products derived from cement within the defect. This study shows the potential for self-limiting flow along wellbore defects despite flow of aggressive scCO2-brine mixtures.
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