Metal–organic frameworks (MOFs) with the highest CO2 uptake capacity are usually those equipped with open metal sites. Here we seek alternative strategies and mechanisms for developing ...high-performance CO2 adsorbents. We demonstrate that through a ligand insertion pore space partition strategy, we can create crystalline porous materials (CPMs) with superior CO2 uptake capacity. Specifically, a new material, CPM-33b-Ni without any open metal sites, exhibits the CO2 uptake capacity comparable to MOF-74 with the same metal (Ni) at 298 K and 1 bar.
Patients with sickle cell disease (SCD) suffer from intense pain that can start during infancy and increase in severity throughout life, leading to hospitalization and poor quality of life. A unique ...feature of SCD is vaso-occlusive crises (VOCs) characterized by episodic, recurrent, and unpredictable episodes of acute pain. Microvascular obstruction during a VOC leads to impaired oxygen supply to the periphery and ischemia reperfusion injury, inflammation, oxidative stress, and endothelial dysfunction, all of which may perpetuate a noxious microenvironment leading to pain. In addition to episodic acute pain, patients with SCD also report chronic pain. Current treatment of moderate to severe pain in SCD is mostly reliant upon opioids; however, long-term use of opioids is associated with multiple side effects. This review presents up-to-date developments in our understanding of the pathobiology of pain in SCD. To help focus future research efforts, major gaps in knowledge are identified regarding how sickle pathobiology evokes pain, pathways specific to chronic and acute sickle pain, perception-based targets of “top-down” mechanisms originating from the brain and neuromodulation, and how pain affects the sickle microenvironment and pathophysiology. This review also describes mechanism-based targets that may help develop novel therapeutic and/or preventive strategies to ameliorate pain in SCD.
PurposeHigh-performance work system (HPWS) has been verified as a promoter of both organizational and individual outcomes. However, this research takes the conflicting view of HPWS to examine the ...impact of HPWS perception on knowledge hoarding. In addition, competitive climate is proposed to mediate the relationship while HPWS psychological contract breach is hypothesized to moderate the HPWS-knowledge hoarding linkage.Design/methodology/approachA quantitative research design is adopted with data collected from 367 MBA and PhD students in Vietnam. Partial least square structural equation modeling is used to test the hypotheses.FindingsThe perception of HPWS increase knowledge hoarding with competitive climate acting as a partial mediator. HPWS psychological contract breach intensifies the relationship.Research limitations/implicationsThe research provides additional evidences to support the dark-side view of HPWS on employees' outcomes. The adoption and implementation of HPWS should be clearly announced to reduce perceptions of mismatch between expectation and reality.Originality/valueThis study is among the first to investigate the association between HPWS and knowledge hoarding. In addition, the mediating role of competitive climate represents a novelty in HPWS research. Finally, the concept of HPWS psychological contract breach has been introduced to the literature.
•We review slippage models for fluid (gas and liquid) flow in nano-size conduits.•We determine the effective slippage at the core scale for shale formations.•We determine the effective pore-throat ...size for slippage at the core scale in shale formations.
A significant fraction of the pore-throat size in the matrix of a shale formation is smaller than 100 nm. Nanofluidics, a field that deals with the transport properties of sub-100-nm conduits, indicates that the fluid flow is enhanced for this range of pore-throat size. However, it is unclear how the slippage at the pore scale (single conduit) controls the effective slippage at the core scale (∼1 in.). The present study reviews the slippage models for the gas and liquid flows inside a single conduit based on the experimental and theoretical studies in the literature. It then investigates the effective enhancement in shale formations using an acyclic pore model, which represents the effective connectivity of the shale pore space at the core scale as it captures the mercury injection capillary pressure measurements (drainage). The effective slippage is presented in terms of governing parameters such as pore pressure and wettability. This study presents the effective pore-throat size, whose corresponding slippage is equal to the effective gas slippage at the core scale, for three shale samples. The numerical simulations indicate that the effective pore-throat size for the gas flow depends on the pore pressure. In addition, the measured permeability with liquid is higher than the nominal permeability, often referred to as the Hagen–Poiseuille model, with no slippage. The presented results have major implications for reservoir characterization based on standard petrophysical measurements.
Recently, magnetic biochars have attracted much attention and exhibited potential for dye removal from industrial wastewater. This work presents a cost-effective magnetic biochar (MBC) nanocomposite ...prepared from rice husk and iron oxide nanoparticles (IONPs), which was tested for removal of crystal violet (CV) from aqueous solution. Morphology and structure of rice husk biochar, IONPs, and MBC were characterized by transmission electron microscopy and x-ray diffraction, and the magnetic property was investigated with a vibrating sample magnetometer. The adsorption capacity of MBC was evaluated through CV removal with experimental parameters including pH solution, adsorbent dosage, and CV concentrations at room temperature. The adsorption kinetics of MBC for CV was also analysed using pseudo-first-order, and pseudo-second-order models. Results showed that rice husk biochar-based magnetic nanocomposite has been successfully prepared. The TEM image showed that many IONPs of 10–14 nm in diameter located inside the biochar network. Experimental results indicated that the adsorption efficiency of MBC rapidly reached 99.02% for CV removal within 15 min. The adsorption capacity of MBC for CV was found at 185.6 mg/g from aqueous solution with pH 6.0, contact time of 120 min at room temperature. This study illustrated the high adsorption capacity of rice husk-based MBC for CV compared to other MBCs and showed also that it is a potential cost-effective material for removal of other organic dyes from industrial wastewater.
Deep Supervision with Intermediate Concepts Li, Chi; Zia, M. Zeeshan; Tran, Quoc-Huy ...
IEEE transactions on pattern analysis and machine intelligence,
2019-Aug.-1, 2019-08-00, 2019-8-1, 20190801, Letnik:
41, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Recent data-driven approaches to scene interpretation predominantly pose inference as an end-to-end black-box mapping, commonly performed by a Convolutional Neural Network (CNN). However, decades of ...work on perceptual organization in both human and machine vision suggest that there are often intermediate representations that are intrinsic to an inference task, and which provide essential structure to improve generalization. In this work, we explore an approach for injecting prior domain structure into neural network training by supervising hidden layers of a CNN with intermediate concepts that normally are not observed in practice. We formulate a probabilistic framework which formalizes these notions and predicts improved generalization via this deep supervision method. One advantage of this approach is that we are able to train only from synthetic CAD renderings of cluttered scenes, where concept values can be extracted, but apply the results to real images. Our implementation achieves the state-of-the-art performance of 2D/3D keypoint localization and image classification on real image benchmarks including KITTI, PASCAL VOC, PASCAL3D+, IKEA, and CIFAR100. We provide additional evidence that our approach outperforms alternative forms of supervision, such as multi-task networks.
Recently, indoor positioning systems have attracted a great deal of research attention, as they have a variety of applications in the fields of science and industry. In this study, we propose an ...innovative and easily implemented solution for indoor positioning. The solution is based on an indoor visible light positioning system and dual-function machine learning (ML) algorithms. Our solution increases positioning accuracy under the negative effect of multipath reflections and decreases the computational time for ML algorithms. Initially, we perform a noise reduction process to eliminate low-intensity reflective signals and minimize noise. Then, we divide the floor of the room into two separate areas using the ML classification function. This significantly reduces the computational time and partially improves the positioning accuracy of our system. Finally, the regression function of those ML algorithms is applied to predict the location of the optical receiver. By using extensive computer simulations, we have demonstrated that the execution time required by certain dual-function algorithms to determine indoor positioning is decreased after area division and noise reduction have been applied. In the best case, the proposed solution took 78.26% less time and provided a 52.55% improvement in positioning accuracy.
A 16-month-old, previously healthy male is hospitalized for new onset seizures. Initial investigation is significant for enterovirus/rhinovirus respiratory infection, abnormal T2 signal predominantly ...in the white matter and scattered microhemorrhages on brain MRI, transaminitis, and thrombocytopenia. His symptoms initially improve on steroid therapy and he is discharged from the hospital. During the ensuing month with the tapering of the steroids, he develops new motor deficits for which he is rehospitalized. His laboratory investigation on readmission is unremarkable. However, there is significant progression of white matter lesions and microhemorrhages on repeat MRI. While in the hospital, he becomes febrile and has seizure recurrence and worsening neurologic symptoms, including cerebral salt wasting and encephalopathy. Subsequent neuroimaging demonstrates cerebral edema and diffuse brain injury. A high index of suspicion for a rare condition ultimately leads us to perform the specialized testing that confirms the diagnosis. We will discuss the diagnostic challenges that arise from an atypical presentation of an uncommon condition, and from the disease progression that is modified by previous interventions.
β-thalassemia is an autosomal recessive disease with the reduction or absence in the production of β-globin chain in the hemoglobin, which is caused by mutations in the Hemoglobin subunit beta (HBB) ...gene. In Vietnam, the number of β-thalassemia carriers range from 1.5 to 25.0%, depending on ethnic and geographical areas, which is much higher than WHO's data worldwide (1.5%). Hence, preimplantation genetic diagnosis (PGD) plays a crucial role in reducing the rate of β-thalassemia affected patients/carriers. In this research, we report the feasibility and reliability of conducting PGD in combination with the use of short tandem repeat (STR) markers in facilitating the birth of healthy children. Six STRs, which were reported to closely linked with the HBB gene, were used on 15 couples of β-thalassemia carriers. With 231 embryos, 168 blastocysts were formed (formation rate of 72.73%), and 88 were biopsied and examined with STRs haplotyping and pedigree analysis. Thus, the results were verified by Sanger sequencing, as a definitive diagnosis. Consequently, 11 over 15 couples have achieved pregnancy of healthy or at least asymptomatic offspring. Only three couples failed to detect any signs of pregnancy such as increased Human Chorionic Gonadotropin (HCG) level, foetal sac, or heart; and one couple has not reached embryo transfer as they were proposed to continue with HLA-matching to screen for a potential umbilical cord blood donor sibling. Thus, these results have indicated that the combination of PGD with STRs analysis confirmed by Sanger sequencing has demonstrated to be a well-grounded and practical clinical strategy to improve the detection of β-thalassemia in the pregnancies of couples at-risk before embryo transfer, thus reducing β-thalassemia rate in the population.
A one-pot cascade sequence to generate synthetically challenging polycyclic scaffolds is reported utilizing a novel Lewis acid gold catalyst for the key cyclization step, enabling the divergent ...synthesis of both 6,6,5-tricyclic and 6,6,6,5-tetracyclic cores through both ligand and reaction condition control. We have combined the intrinsic complexity and stereoselectivity of cycloadditions with the electronic and steric properties of gold complexes to selectively generate complex polycyclic scaffolds in a single operation.