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1.
Chem Asian J ; 19(2): e202300833, 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-37997488

ABSTRACT

Hydrogen plays a crucial role in the future energy landscape owing to its high energy density. However, finding an ideal storage material is the key challenge to the success of the hydrogen economy. Various solid-state hydrogen storage materials, such as metal hydrides, have been developed to realize safe, effective, and compact hydrogen storage. However, low kinetics and thermodynamic stability lead to a high working temperature and a low hydrogen sorption rate of the metal hydrides. Using scaffolds made from porous materials like silica to confine the metal hydrides is necessary for better and improved hydrogen storage. Therefore, this article reviews porous silica-based scaffolds as an ideal material for improved hydrogen storage. The outcome showed that confining the metal hydrides using scaffolds based on porous silica significantly increases their storage capacities. It was also found that the structural modifications of the silica-based scaffold into a hollow structure further improved the storage capacity and increased the affinity and confinement ability of the metal hydrides, which prevents the agglomeration of metal particles during the adsorption/desorption process. Hence, the structural modifications of the silica material into a fibrous and hollow material are recommended to be crucial for further enhancing the metal hydride storage capacity.

4.
Sci Rep ; 8(1): 11087, 2018 Jul 23.
Article in English | MEDLINE | ID: mdl-30038363

ABSTRACT

Thulium iron garnet (TmIG) films with perpendicular magnetic anisotropy (PMA) were grown on gadolinium gallium garnet (GGG) (111) substrates by off-axis sputtering. High-resolution synchrotron radiation X-ray diffraction studies and spherical aberration-corrected scanning transmission electron microscope (Cs-corrected STEM) images showed the excellent crystallinity of the films and their sharp interface with GGG. Damping constant of TmIG thin film was determined to be 0.0133 by frequency-dependent ferromagnetic resonance (FMR) measurements. The saturation magnetization (Ms) and the coercive field (Hc) were obtained systematically as a function of the longitudinal distance (L) between the sputtering target and the substrate. A 170% enhancement of PMA field (H⊥) was achieved by tuning the film composition to increase the tensile strain. Moreover, current-induced magnetization switching on a Pt/TmIG structure was demonstrated with an ultra-low critical current density (jc) of 2.5 × 106 A/cm2, an order of magnitude smaller than the previously reported value. We were able to tune Ms, Hc and H⊥ to obtain an ultra-low jc of switching the magnetization, showing the great potential of sputtered TmIG films for spintronics.

5.
Epidemiol Infect ; 146(11): 1350-1358, 2018 08.
Article in English | MEDLINE | ID: mdl-29880077

ABSTRACT

Our objective was to identify predictors of severe acute respiratory infection in hospitalised patients and understand the impact of vaccination and neuraminidase inhibitor administration on severe influenza. We analysed data from a study evaluating influenza vaccine effectiveness in two Michigan hospitals during the 2014-2015 and 2015-2016 influenza seasons. Adults admitted to the hospital with an acute respiratory infection were eligible. Through patient interview and medical record review, we evaluated potential risk factors for severe disease, defined as ICU admission, 30-day readmission, and hospital length of stay (LOS). Two hundred sixteen of 1119 participants had PCR-confirmed influenza. Frailty score, Charlson score and tertile of prior-year healthcare visits were associated with LOS. Charlson score >2 (OR 1.5 (1.0-2.3)) was associated with ICU admission. Highest tertile of prior-year visits (OR 0.3 (0.2-0.7)) was associated with decreased ICU admission. Increasing tertile of visits (OR 1.5 (1.2-1.8)) was associated with 30-day readmission. Frailty and prior-year healthcare visits were associated with 30-day readmission among influenza-positive participants. Neuraminidase inhibitors were associated with decreased LOS among vaccinated participants with influenza A (HR 1.6 (1.0-2.4)). Overall, frailty and lack of prior-year healthcare visits were predictors of disease severity. Neuraminidase inhibitors were associated with reduced severity among vaccine recipients.


Subject(s)
Influenza, Human/epidemiology , Respiratory Tract Infections/epidemiology , Acute Disease , Adolescent , Adult , Aged , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/therapeutic use , Female , Frailty , Health Status , Humans , Influenza Vaccines/administration & dosage , Inpatients , Intensive Care Units/statistics & numerical data , Interviews as Topic , Length of Stay/statistics & numerical data , Male , Michigan/epidemiology , Middle Aged , Morbidity , Nasopharynx/virology , Neuraminidase/antagonists & inhibitors , Patient Readmission/statistics & numerical data , Risk Factors , Severity of Illness Index , Young Adult
6.
ACS Nano ; 12(6): 5913-5922, 2018 06 26.
Article in English | MEDLINE | ID: mdl-29874030

ABSTRACT

There is a need to monitor patients with cancer of the head and neck postradiation therapy, as diminished swallowing activity can result in disuse atrophy and fibrosis of the swallowing muscles. This paper describes a flexible strain sensor comprising palladium nanoislands on single-layer graphene. These piezoresistive sensors were tested on 14 disease-free head and neck cancer patients with various levels of swallowing function: from nondysphagic to severely dysphagic. The patch-like devices detected differences in (1) the consistencies of food boluses when swallowed and (2) dysphagic and nondysphagic swallows. When surface electromyography (sEMG) is obtained simultaneously with strain data, it is also possible to differentiate swallowing vs nonswallowing events. The plots of resistance vs time are correlated to specific events recorded by video X-ray fluoroscopy. Finally, we developed a machine-learning algorithm to automate the identification of bolus type being swallowed by a healthy subject (86.4%. accuracy). The algorithm was also able to discriminate between swallows of the same bolus from either the healthy subject or a dysphagic patient (94.7% accuracy). Taken together, these results may lead to noninvasive and home-based systems for monitoring of swallowing function and improved quality of life.


Subject(s)
Deglutition/physiology , Electromyography/methods , Graphite/chemistry , Head and Neck Neoplasms/physiopathology , Head and Neck Neoplasms/radiotherapy , Metal Nanoparticles/chemistry , Monitoring, Physiologic/methods , Adult , Aged , Aged, 80 and over , Algorithms , Female , Humans , Machine Learning , Male , Middle Aged , Palladium/chemistry , Young Adult
7.
Nat Commun ; 9(1): 223, 2018 01 15.
Article in English | MEDLINE | ID: mdl-29335558

ABSTRACT

Harnessing the spin-momentum locking of topological surface states in conjunction with magnetic materials is the first step to realize novel topological insulator-based devices. Here, we report strong interfacial coupling in Bi2Se3/yttrium iron garnet (YIG) bilayers manifested as large interfacial in-plane magnetic anisotropy (IMA) and enhancement of damping probed by ferromagnetic resonance. The interfacial IMA and damping enhancement reaches a maximum when the Bi2Se3 film approaches its two-dimensional limit, indicating that topological surface states play an important role in the magnetization dynamics of YIG. Temperature-dependent ferromagnetic resonance of Bi2Se3/YIG reveals signatures of the magnetic proximity effect of TC as high as 180 K, an emerging low-temperature perpendicular magnetic anisotropy competing the high-temperature IMA, and an increasing exchange effective field of YIG steadily increasing toward low temperature. Our study sheds light on the effects of topological insulators on magnetization dynamics, essential for the development of topological insulator-based spintronic devices.

8.
Eye (Lond) ; 31(5): 762-770, 2017 May.
Article in English | MEDLINE | ID: mdl-28106889

ABSTRACT

PurposeTo report the incidence and associated factors for the development of vitreomacular interface abnormality (VMIA) in patients with diabetic macular edema (DME) who received intravitreal injection (IVI) of anti-VEGF (Bevacizumab and Ranibizumab) treatment.MethodsA retrospective observational study. Patients with DME followed at least 6 months were reviewed. Baseline best-corrected visual acuity (BCVA), central retinal thickness (CRT) and final BCVA, CRT in eyes with and without VMIA were compared. Multiple logistic regression was also used to investigate the risk factors of VMIA formation in patients with DME treated by anti-VEGF.ResultsA total of 201 eyes in 142 patients met the inclusion criteria of the study. VMIA developed in 44 eyes (21.89%) of patients during a mean follow-up period of 40.84 months. The estimated mean incidence of VMIA formation was 6.43% per year. Poor baseline BCVA was found to be a risk factor for VMIA development (P=0.001, odds ratio=5.299, 95% confidence interval: 1.972 to 14.238). There was no difference between eyes with and without VMIA formation in improving BCVA (P=0.557) and lowering the macular edema (eyes without VMIA formation: -107.72±171.91 µm; eyes with VMIA formation: -155.02±212.27 µm, P=0.133).ConclusionsThis study revealed the incidence of VMIA formation in IVI anti-VEGF treated DME eyes was 6.43%. Poor baseline BCVA was found to be a risk factor for VMIA formation. Both eyes with and without VMIA development had favorable response to anti-VEGF treatment.


Subject(s)
Bevacizumab/adverse effects , Choroid Diseases/epidemiology , Diabetic Retinopathy/drug therapy , Eye Diseases, Hereditary/epidemiology , Macular Edema/drug therapy , Ranibizumab/adverse effects , Retinal Degeneration/epidemiology , Angiogenesis Inhibitors/administration & dosage , Angiogenesis Inhibitors/adverse effects , Bevacizumab/administration & dosage , Choroid Diseases/etiology , Diabetic Retinopathy/complications , Diabetic Retinopathy/diagnosis , Eye Diseases, Hereditary/etiology , Female , Follow-Up Studies , Humans , Incidence , Intravitreal Injections , Macular Edema/diagnosis , Macular Edema/etiology , Male , Middle Aged , Ranibizumab/administration & dosage , Retina/pathology , Retinal Degeneration/etiology , Retrospective Studies , Risk Factors , Taiwan/epidemiology , Time Factors , Tomography, Optical Coherence , Vascular Endothelial Growth Factor A/antagonists & inhibitors , Visual Acuity
10.
Neuroscience ; 289: 71-84, 2015 Mar 19.
Article in English | MEDLINE | ID: mdl-25592429

ABSTRACT

Recent studies of electromagnetic ultra-slow waves (⩽0.1Hz) have suggested that they play a role in the integration of otherwise disassociated brain regions supporting vital functions (Ackermann and Borbely, 1997; Picchioni et al., 2010; Knyazev, 2012; Le Bon et al., 2012). We emphasize this spectral domain in probing sensor coherence issues raised by these studies using Hilbert phase coherences in the human MEG. In addition, we ask: will temporal-spatial phase coherence in regional brain oscillations obtained from the ultraslow spectral bands of multi-channel magnetoencephalograms (MEG) differentiate resting, "task-free" MEG records of normal control and schizophrenic subjects? The goal of the study is a comparison of the relative persistence of intra-regional phase locking values (PLVs), among 10, region-defined, sensors in examined in the resting multichannel, MEG records as a function of spectral frequency bands and diagnostic category. The following comparison of Hilbert-transform-engendered relative phases of each designated spectral band was made using their pair-wise PLVs. This indicated the proportion of shared cycle time in which the phase relations between the index location and reference leads were maintained. Leave one out, bootstrapping of the PLVs via a support vector machine (SVM), classified clinical status with 97.3% accuracy. It was generally the case that spectral bands ⩽1.0Hz generated the highest values of the PLVs and discriminated best between control and patient populations. We conclude that PLV analysis of the oscillatory patterns of MEG recordings in the ultraslow frequency bands suggest their functional significance in intra-regional signal coherence and provide a higher rate of classification of patients and normal subjects than the other spectral domains examined.


Subject(s)
Brain Waves , Neocortex/physiology , Neocortex/physiopathology , Schizophrenia/classification , Schizophrenia/physiopathology , Adult , Algorithms , Female , Humans , Magnetoencephalography/methods , Male , Rest , Signal Processing, Computer-Assisted , Support Vector Machine
11.
Neuroscience ; 267: 91-101, 2014 May 16.
Article in English | MEDLINE | ID: mdl-24613718

ABSTRACT

In seeking evidence for the presence and characteristic range of coupled time scale(s) of putative implicit turbulent attractors of dorsal frontal lobe magnetic fields, the recorded nonstationary, nonlinear MEG signals were non-orthogonally decomposed using Huang's Empirical Mode Decomposition, EMD, (Huang and Attoh-Okine, 2005) into 16 Intrinsic Mode Functions, EMD→IMFi, i=1…16. Measures known to be invariant in non-uniformly hyperbolic (turbulent) dynamical systems, topological entropy, hT, metric entropy, hM, non-uniform entropy, hU and power spectral scaling exponent, α, were imposed on each of the IMFi which evidenced most clearly an invariant temporal scale zone of IMFi, i=6…11, for hT, which we have found to be the most robust of invariant measures of MEG's magnetic field turbulent attractors (Mandell et al., 2011a,b; Mandell, 2013). The ergodic theory of dynamical systems (Walters, 1982; Pollicott and Yuri, 1998) allows the inference that an implicit attractor with consistently hT>0 will also evidence at least one positive Lyapounov exponent indicating the presence of a turbulent attractor with exponential separation of nearby initial conditions, exponential convergence of distant points and disordering, mixing, of orbital sequences. It appears that this approach permits the inference of the presence of chaotic, turbulent attractor and its characteristic time scales without the invocation of arbitrary n-dimensional embedding, phase space reconstructions or (inappropriate) orthogonal decompositions.


Subject(s)
Frontal Lobe/physiology , Magnetoencephalography , Models, Biological , Nonlinear Dynamics , Entropy , Female , Humans , Male , Spectrum Analysis , Time Factors
13.
Transfusion ; 52(10): 2220-4, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22339270

ABSTRACT

BACKGROUND: Red blood cell (RBC) alloimmunization is reported to occur at an incidence of 5.2% to 23.5% among patients with thalassemia requiring chronic transfusion. With very limited data on alloimmunization among the Chinese population, a territory-wide study has been performed to look at its prevalence among Chinese thalassemia major patients. STUDY DESIGN AND METHODS: A retrospective study was conducted by reviewing RBC request records for patients with thalassemia major in Hong Kong from 2006 to 2009. Demographic information and serologic data were retrieved for analysis. RESULTS: A total of 382 patients were identified and consisted of 190 males and 192 females with a median age of 23 ± 10.4 (range, 0.25 to 52) years. Eighty-eight patients (23.0%) were reported to have RBC antibodies. Of them, 114 alloantibodies, 18 autoantibodies, and 19 unidentified antibodies were identified. Anti-E (42, 39.3%), anti-Mi(a)/Mur (33, 30.85%), anti-c (14, 13.1%), and anti-Jk(a) (seven, 6.55%) were the commonest antibodies reported. However, one case of anti-K (0.9%) and two cases of anti-Fy(b) (1.9%) were reported. Seven of the 18 patients with autoantibodies contained a total of 13 alloantibodies. They were anti-E (five, 38.4%), anti-Mi(a)/Mur (four, 30.8%), anti-Jk(a) (two, 15.4%), anti-c (one, 7.7%), and anti-Fy(b) (one, 7.7%). CONCLUSION: It is the first comprehensive study on Chinese thalassemia major patients. Clinically significant alloantibodies are different from those observed in the Western population, although antibodies developed against Rh antigens are still common. Chinese patients are less likely to have antibodies against Kell and Duffy blood group antigens, but are more prone to develop antibodies against the Miltenberger antigens.


Subject(s)
Autoantibodies/blood , Blood Group Antigens/immunology , Blood Transfusion , Isoantibodies/blood , beta-Thalassemia/blood , Adolescent , Adult , Blood Group Incompatibility/etiology , Blood Group Incompatibility/immunology , Blood Grouping and Crossmatching , Child , Child, Preschool , China/ethnology , Ethnicity , Female , HLA Antigens/immunology , Histocompatibility Testing , Hong Kong , Hospitals, Public/statistics & numerical data , Humans , Immunization , Infant , Male , Middle Aged , Retrospective Studies , Transfusion Reaction , Young Adult , beta-Thalassemia/epidemiology , beta-Thalassemia/therapy
14.
Proc Natl Acad Sci U S A ; 107(26): 11889-94, 2010 Jun 29.
Article in English | MEDLINE | ID: mdl-20547848

ABSTRACT

The mushroom Coprinopsis cinerea is a classic experimental model for multicellular development in fungi because it grows on defined media, completes its life cycle in 2 weeks, produces some 10(8) synchronized meiocytes, and can be manipulated at all stages in development by mutation and transformation. The 37-megabase genome of C. cinerea was sequenced and assembled into 13 chromosomes. Meiotic recombination rates vary greatly along the chromosomes, and retrotransposons are absent in large regions of the genome with low levels of meiotic recombination. Single-copy genes with identifiable orthologs in other basidiomycetes are predominant in low-recombination regions of the chromosome. In contrast, paralogous multicopy genes are found in the highly recombining regions, including a large family of protein kinases (FunK1) unique to multicellular fungi. Analyses of P450 and hydrophobin gene families confirmed that local gene duplications drive the expansions of paralogous copies and the expansions occur in independent lineages of Agaricomycotina fungi. Gene-expression patterns from microarrays were used to dissect the transcriptional program of dikaryon formation (mating). Several members of the FunK1 kinase family are differentially regulated during sexual morphogenesis, and coordinate regulation of adjacent duplications is rare. The genomes of C. cinerea and Laccaria bicolor, a symbiotic basidiomycete, share extensive regions of synteny. The largest syntenic blocks occur in regions with low meiotic recombination rates, no transposable elements, and tight gene spacing, where orthologous single-copy genes are overrepresented. The chromosome assembly of C. cinerea is an essential resource in understanding the evolution of multicellularity in the fungi.


Subject(s)
Chromosomes, Fungal/genetics , Coprinus/genetics , Evolution, Molecular , Base Sequence , Chromosome Mapping , Coprinus/cytology , Coprinus/growth & development , Cytochrome P-450 Enzyme System/genetics , DNA Primers/genetics , Fungal Proteins/genetics , Gene Duplication , Genome, Fungal , Meiosis/genetics , Molecular Sequence Data , Multigene Family , Phylogeny , Protein Kinases/genetics , RNA, Fungal/genetics , Recombination, Genetic , Retroelements/genetics
15.
J Bone Joint Surg Br ; 92(4): 500-7, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20357325

ABSTRACT

Components from 73 failed knee replacements (TKRs) consisting of rotating-platform, mobile-bearing and fixed-bearing implants were examined to assess the patterns of wear. The patterns were divided into low-grade (burnishing, abrasion and cold flow) and high-grade (scratching, pitting/metal embedding and delamination) to assess the severity of the wear of polyethylene. The rotating-platform group had a higher incidence of low-grade wear on the upper surface compared with the fixed-bearing group. By contrast, high-grade wear comprising scratching, pitting and third-body embedding was seen on the lower surface. Linear regression analysis showed a significant correlation of the wear scores between the upper and lower surfaces of the tibial insert (R(2) = 0.29, p = 0.04) for the rotating-platform group, but no significant correlation was found for the fixed-bearing counterpart. This suggests that high-grade wear patterns on the upper surface are reduced with the rotating-platform design. However, the incidence of burnishing, pitting/third-body embedding and scratching wear patterns on the lower surface was higher compared with that in the fixed-bearing knee.


Subject(s)
Knee Prosthesis , Prosthesis Failure , Tibia/surgery , Arthroplasty, Replacement, Knee/instrumentation , Arthroplasty, Replacement, Knee/methods , Equipment Failure Analysis/methods , Female , Humans , Male , Prosthesis Design , Reoperation , Stress, Mechanical
17.
Ann Rheum Dis ; 68(9): 1482-5, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19015211

ABSTRACT

OBJECTIVE: To validate a model which predicts progression from undifferentiated arthritis (UA) to RA, in a Canadian UA cohort. METHODS: The prediction rule, comprising variables which are scored from 0 to 13, with higher scores reflecting an increased risk of RA, was applied to baseline characteristics of all patients with UA. Progression to RA was determined at 6 months. RESULTS: 105 patients were identified. By 6 months, 80 (76%) had developed RA while 25 (24%) had developed another diagnosis. Number of tender and swollen joints, rheumatoid factor positivity, anti-cyclic citrullinated peptide positivity, poor functional status and high disease activity were associated with development of RA (p<0.01). Median prediction score was 8.0 for progressors, 5.0 for non-progressors. With these cut-off points, 18 (72%) patients with scores < or =5 did not develop RA, while 35 (97%) with scores > or =8 did develop RA. CONCLUSIONS: High scores in our cohort predicted those who progressed to RA by 6 months. Baseline scores > or =8 corresponded with higher rates of progression.


Subject(s)
Arthritis/diagnosis , Adult , Antirheumatic Agents/therapeutic use , Arthritis/pathology , Arthritis, Rheumatoid/diagnosis , Arthritis, Rheumatoid/pathology , Autoantibodies/blood , Biomarkers/blood , Disease Progression , Early Diagnosis , Epidemiologic Methods , Female , Humans , Male , Middle Aged , Peptides, Cyclic/immunology , Prognosis , Rheumatoid Factor/blood
19.
Int J Artif Organs ; 31(5): 439-49, 2008 May.
Article in English | MEDLINE | ID: mdl-18609518

ABSTRACT

BACKGROUND: Chondrocytes can detect and respond to the mechanical environment by altering their metabolism. This study was designed to explore the effects of dynamic compression on chondrocyte metabolism. METHODS: Chondrocytes were harvested from newborn Wistar rats. After 7 days of expansion, chondrocytes embedded in agarose discs underwent uniaxial unconfined dynamic compression loads at different amplitudes (5%, 10%, and 15%) and frequencies (0.5 Hz, 1.0 Hz, 2.0 Hz, and 3.0 Hz) with a duration of 24 hours. The delayed effects on the chondrocytes were studied at 1, 3, and 7 days after the experiment. RESULTS: The results showed that at 10% strain, higher-frequency compression pressure can enhance the proliferation of chondrocytes. The synthesis of glycosaminoglycan (GAG) increased at 10%-15% strain and a 1-Hz load. The synthesis of nitric oxide (NO) increased at the 0.5-Hz load; while decreasing at the 15% strain. With 10% strain, 1 Hz dynamic compression, the proliferation of chondrocytes and GAG synthesis increased and persisted for 7 days, and NO synthesis decreased at the third and seventh days of culture. CONCLUSIONS: This study showed that chondrocytes respond metabolically to compressive loading, which is expected to modulate the growth and the resultant biomechanical properties of these tissue-engineered constructs during culture.


Subject(s)
Chondrocytes/metabolism , Stress, Mechanical , Animals , Cells, Cultured , Glycosaminoglycans/biosynthesis , Nitric Oxide/metabolism , Rats , Vibration/adverse effects
20.
J Theor Biol ; 254(1): 14-26, 2008 Sep 07.
Article in English | MEDLINE | ID: mdl-18571676

ABSTRACT

A two-component model is developed consisting of a discrete loop of cardiac cells that circulates action potentials as well as a pacing mechanism. Physiological properties of cells such as restitutions of refractoriness and of conduction velocity are given via experimentally measured functions. The dynamics of circulating pulses and the pacer's action are regulated by two threshold relations. Patterns of spontaneous initiations and terminations of reentry (SITR) generated by this system are studied through numerical simulations and analytical observations. These patterns can be regular or irregular; causes of irregularities are identified as the threshold bistability (T-bistability) of reentrant circulation and in some cases, also phase-resetting interactions with the pacer.


Subject(s)
Computer Simulation , Heart Conduction System/physiology , Models, Cardiovascular , Action Potentials/physiology , Electrocardiography , Heart Block/physiopathology , Humans , Myocardial Contraction/physiology , Tachycardia/physiopathology
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