The aim of this paper is to present a comprehensive review on renewable methane fuel production through the biological route of biomethanation process from major lignocellulosic agricultural crop ...waste biomass (maize, wheat, rice and sugarcane). Global annual approximate production of major agriculture based lignocellulosic biomass has been explored. Fundamental requirements of biomethanation process have been discussed in details for optimum production of methane. The essential properties of biomass (proximate, ultimate and compositional) conscientious for quality of derived fuel have also been presented along with the pretreatment requirements for lignocellulosic biomass. Methane generation potential of the major lignocellulosic agricultural crop biomass has been explored and presented. Furthermore, the methane production potential and its energetic analysis have also been compared with the bio-ethanol productions. The overall parametric analysis involved in anaerobic digestion and alcoholic fermentation explore that methane generation from lignocellulosic agricultural crop waste biomass is more economical and environmentally beneficial way of biomass utilization in a sustainable way of energy production.
Peripheral arterial disease is a chronic vascular disease characterized by impaired circulation to the lower extremities. Its most severe stage, known as critical limb ischemia (CLI), puts patients ...at an increased risk of cardiovascular events, amputation, and death. The objective of this literature review is to describe the burden of disease across a comprehensive set of domains-epidemiologic, clinical, humanistic, and economic-focusing on key studies published in the last decade. CLI prevalence in the United States is estimated to be approximately 2 million and is likely to rise in the coming years given trends in important risk factors such as age, diabetes, and smoking. Hospitalization for CLI patients is common and up to 60% are readmitted within 6 months. Amputation rates are unacceptably high with a disproportionate risk for certain demographic and socioeconomic groups. In addition to limb loss, CLI patients also have reduced life expectancy with mortality typically exceeding 50% by 5 years. Given the poor clinical prognosis, it is unsurprising that the quality of life burden associated with CLI is significant. Studies assessing quality of life in CLI patients have used a variety of generic and disease-specific measures and all document a substantial impact of the disease on the patient's physical, social, and emotional health status compared to population norms. Finally, the poor clinical outcomes and increased medical resource use lead to a considerable economic burden for national health care systems. However, published cost studies are not comprehensive and, therefore, likely underestimate the true economic impact of CLI. Our summary documents a sobering assessment of CLI burden-a poor clinical prognosis translating into diminished quality of life and high costs for millions of patients. Continued prevention efforts and improved treatment strategies are the key to ameliorating the substantial morbidity and mortality associated with this disease.
►Hydrothermal pretreatment offer accelerated pre-hydrolysis of rice straw biomass. ► 5% NaOH addition is a mandatory requirement in rice straw hydrothermal substrate. ► Methane production was ...increased by 222.0% for hydrothermal pretreated substrates. ► Hydrothermal pretreatment found as the promising method for improved biomethanation.
This paper presents the results of an experimental batch methane fermentation (at 37°C mesophilic temperature) study carried out on untreated and pretreated substrates of rice straw using NaOH and hydrothermal pretreatments. 3% NaOH pretreatment was given to ground rice straw biomass for 120h at 37°C and hydrothermal pretreatment was given for 10min at 200°C. It was observed that NaOH addition is a mandatory requirement for maintaining a suitable range of pH and starting the biogas production from hydrothermal pretreated biomass slurry of rice straw. The fed substrate concentrations were maintained at 5% TS (50g TS/L). The study revealed into 140.0L/kg VSa biogas and 59.8L/kg VSa methane from untreated rice straw substrate. However, NaOH pretreated substrate resulted into 184.8L/kg VSa biogas and 74.1L/kg VSa methane. Hydrothermal pretreated followed by 5% NaOH added substrate resulted into highest biogas and methane production yields as 315.9L/kg VSa and 132.7L/kg VSa, respectively. NaOH pretreated substrate showed an increase of 132.0% in biogas production and 123.9% in methane production relative to the untreated substrate. However, the hydrothermal pretreated substrate had resulted into an increase of 225.6% in biogas production and 222.0% in methane production relative to untreated rice straw substrate. Hydrothermal pretreatment provided an accelerated pre-hydrolysis of biomass contents during the treatment process and thereby resulted into enhanced biogas and methane production yields.
This paper presents the results of an experimental methane fermentation study on untreated, NaOH and hydrothermal pretreated substrates of wheat straw. Experiments were conducted at 37 °C (mesophilic ...temperature). Substrates concentration were maintained at 4.45% VS (44.5 g VS/L). Untreated wheat straw substrate had resulted into specific methane and biogas production yields of 78.4 L/kg VSa and 188.4 L/kg VSa, respectively. The specific methane and biogas production yield of NaOH pretreated wheat straw substrate had resulted into 165.9 L/kg VSa and 353.2 L/kg VSa, respectively. Hydrothermal pretreated wheat straw substrate had resulted to yield specific methane and biogas production of 94.1 L/kg VSa and 205.7 L/kg VSa, respectively. NaOH pretreated substrate produced 87.5% higher biogas production and 111.6% higher methane production compared to the untreated wheat straw substrate. Hydrothermal pretreated substrate had resulted into an increase of 9.2% in biogas production and 20.0% in methane production compared to that of untreated wheat straw substrate.
► NaOH, hydrothermal pretreated substrates of wheat straw were studied for Methane fermentation. ► Minimum 5% NaOH addition is required for hydrothermal substrate to maintain a suitable pH. ► Biogas and methane production were increased by 87.5% and 111.6% for 4% NaOH pretreated substrate. ► Wheat straw NaOH pretreatment found a potential method to enhance biogas and methane production.
Radiation detectors dedicated to time-of-flight positron emission tomography (PET) have been developed, and coincidence time resolution (CTR) of sub-100 ps full width at half maximum (FWHM) has been ...achieved by carefully optimizing scintillators and photodetectors. Achieving a CTR of 30 ps FWHM by using a pair of annihilation γ-rays would allow us to directly localize the annihilation point within an accuracy of 4.5 mm. Such direct localization can potentially eliminate the requirement of image reconstruction processes in clinical PET systems, which would have a huge impact on clinical protocols and molecular imaging. To obtain such a high CTR, researchers have investigated the use of prompt emissions such as Cherenkov radiation and hot-intra band luminescence. Although it is still challenging to achieve a CTR of 30 ps FWHM even with a Cherenkov-based detector, the experimentally measured CTR is approaching the goal. In this work, we developed a Cherenkov-radiator-integrated micro-channel plate photomultiplier tube (CRI-MCP-PMT), where there are no optical boundaries between the radiator and photocathode, and its timing performance was investigated. By removing the optical boundaries, reflections are eliminated and transmission to the photocathode is improved, resulting in high timing capability. As a result, a CTR of 30.1 ± 2.4 ps FWHM, which is equivalent to a position resolution of 4.5 ± 0.3 mm along a line of response (LOR), was obtained by using a pair of CRI-MCP-PMTs.
Abstract
Ferroaxial materials that exhibit spontaneous ordering of a rotational structural distortion with an axial vector symmetry have gained growing interest, motivated by recent extensive studies ...on ferroic materials. As in conventional ferroics (e.g., ferroelectrics and ferromagnetics), domain states will be present in the ferroaxial materials. However, the observation of ferroaxial domains is non-trivial due to the nature of the order parameter, which is invariant under both time-reversal and space-inversion operations. Here we propose that NiTiO
3
is an order-disorder type ferroaxial material, and spatially resolve its ferroaxial domains by using linear electrogyration effect: optical rotation in proportion to an applied electric field. To detect small signals of electrogyration (order of 10
−5
deg V
−1
), we adopt a recently developed difference image-sensing technique. Furthermore, the ferroaxial domains are confirmed on nano-scale spatial resolution with a combined use of scanning transmission electron microscopy and convergent-beam electron diffraction. Our success of the domain visualization will promote the study of ferroaxial materials as a new ferroic state of matter.
A large variety of nanometre-scale devices have been investigated in recent years that could overcome the physical and economic limitations of current semiconductor devices. To be of technological ...interest, the energy consumption and fabrication cost of these 'nanodevices' need to be low. Here we report a new type of nanodevice, a quantized conductance atomic switch (QCAS), which satisfies these requirements. The QCAS works by controlling the formation and annihilation of an atomic bridge at the crossing point between two electrodes. The wires are spaced approximately 1 nm apart, and one of the two is a solid electrolyte wire from which the atomic bridges are formed. We demonstrate that such a QCAS can switch between 'on' and 'off' states at room temperature and in air at a frequency of 1 MHz and at a small operating voltage (600 mV). Basic logic circuits are also easily fabricated by crossing solid electrolyte wires with metal electrodes.
Achieving direct imaging of the annihilation position of a positron on an event-by-event basis using an ultrafast detector would have a great impact on the field of nuclear medicine. Cherenkov ...emission is the most attractive physical phenomenon for realizing such an ultrafast timing performance. Moreover, a microchannel-plate photomultiplier tube (MCP-PMT) is one of the most promising photodetectors for fully exploiting the fast timing properties of Cherenkov emission owing to its excellent single photon time resolution of 25 ps full width at half maximum (FWHM). However, as the MCP structure generally contains a lead compound, the gamma rays frequently and directly interact with the MCP, resulting in the degradation of its timing performance and generation of undesirable side peaks in its coincidence timing histogram. To overcome this problem, we have developed a new MCP-PMT based on an MCP consisting of borosilicate glass, thus drastically reducing the probability of the photoelectric effect occurring in the MCP. To evaluate its insensitivity to gamma rays and its timing performance, a coincidence experiment was performed and showed that the probability of direct interactions was reduced by a factor of 3.4. Moreover, a coincidence time resolution of 35.4 ± 0.4 ps FWHM, which is equivalent to a position resolution of 5.31 mm, was obtained without any pulse height/area cut, improving to 28.7 ± 3.0 ps when selecting on the highest amplitude events by careful optimization of the voltage divider circuit of the new MCP-PMT. The timing performance of this new MCP-PMT presents an important step toward making direct imaging possible.
Summary
Root amputation, extraction of a single tooth, bone loss or severe tooth mobility, and an unclosed wound were significantly associated with increased risk of developing medication-related ...osteonecrosis of the jaw (MRONJ). We recommend a minimally traumatic extraction technique, removal of any bone edges, and mucosal wound closure as standard procedures in patients receiving bisphosphonates.
Introduction
Osteonecrosis of the jaws can occur following tooth extraction in patients receiving bisphosphonate drugs. Various strategies for minimizing the risk of MRONJ have been advanced, but no studies have comprehensively analyzed the efficacy of factors such as primary wound closure, demographics, and drug holidays in reducing its incidence. The purpose of this study was to retrospectively investigate the relationships between these various risk factors after tooth extraction in patients receiving oral bisphosphonate therapy.
Methods
Risk factors for MRONJ after tooth extraction were evaluated using univariate and multivariate analysis. All patients were investigated with regard to demographics; type and duration of oral bisphosphonate use; whether they underwent a discontinuation of oral bisphosphonates before tooth extraction (drug holiday), and the duration of such discontinuation; and whether any additional surgical procedures (e.g., incision, removal of bone edges, root amputation) were performed.
Results
We found that root amputation (OR = 6.64), extraction of a single tooth (OR = 3.70), bone loss or severe tooth mobility (OR = 3.60), and an unclosed wound (OR = 2.51) were significantly associated with increased risk of developing MRONJ.
Conclusions
We recommend a minimally traumatic extraction technique, removal of any bone edges, and mucosal wound closure as standard procedures in patients receiving bisphosphonates. We find no evidence supporting the efficacy of a pre-extraction short-term drug holiday from oral bisphosphonates in reducing the risk of MRONJ.
ABSTRACT
Intraspecific variations in pollen morphological traits are poorly studied. Interspecific variations are often associated with pollination systems and pollinator types. Altitudinal ...environmental changes, which can influence local pollinator assemblages, provide opportunities to explore differentiation in pollen traits of a single species over short distances. The aim of this study is to examine intraspecific variations in pollen traits of an insect‐pollinated shrub, Weigela hortensis (Caprifoliaceae), along an altitudinal gradient.
Pollen spine phenotypes (length, number and density), pollen diameter, lipid mass (pollenkitt) around pollen grains, pollen production per flower and pollinator assemblages were compared at four sites at different altitudes.
Spine length and the spine length/diameter ratio of pollen grains were greater at higher altitudes but not correlated with flower or plant size. Spine number and density increased as flower size increased, and pollen lipid mass decreased as plant size increased. Bees were the predominant pollinators at low‐altitude sites whereas flies, specifically Oligoneura spp. (Acroceridae), increased in relative abundance with increasing altitude.
The results of this study suggest that the increase in spine length with altitude was the result of selection favouring longer spines at higher‐altitude sites and/or shorter spines at lower‐altitude sites. The altitudinal variation in selection pressure on spine length could reflect changes in local pollinator assemblages with altitude.
Weigela hortensis pollen grains from high altitudes had longer spines than those from low altitudes, which may have been driven by a change in the main pollinators from bees to flies.
PDF
