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1.
Nature ; 596(7871): 232-237, 2021 08.
Article in English | MEDLINE | ID: mdl-34381234

ABSTRACT

Room-temperature optoelectronic devices that operate at short-wavelength and mid-wavelength infrared ranges (one to eight micrometres) can be used for numerous applications1-5. To achieve the range of operating wavelengths needed for a given application, a combination of materials with different bandgaps (for example, superlattices or heterostructures)6,7 or variations in the composition of semiconductor alloys during growth8,9 are used. However, these materials are complex to fabricate, and the operating range is fixed after fabrication. Although wide-range, active and reversible tunability of the operating wavelengths in optoelectronic devices after fabrication is a highly desirable feature, no such platform has been yet developed. Here we demonstrate high-performance room-temperature infrared optoelectronics with actively variable spectra by presenting black phosphorus as an ideal candidate. Enabled by the highly strain-sensitive nature of its bandgap, which varies from 0.22 to 0.53 electronvolts, we show a continuous and reversible tuning of the operating wavelengths in light-emitting diodes and photodetectors composed of black phosphorus. Furthermore, we leverage this platform to demonstrate multiplexed nondispersive infrared gas sensing, whereby multiple gases (for example, carbon dioxide, methane and water vapour) are detected using a single light source. With its active spectral tunability while also retaining high performance, our work bridges a technological gap, presenting a potential way of meeting different requirements for emission and detection spectra in optoelectronic applications.

2.
Nature ; 583(7818): 785-789, 2020 07.
Article in English | MEDLINE | ID: mdl-32690938

ABSTRACT

An exciton is the bosonic quasiparticle of electron-hole pairs bound by the Coulomb interaction1. Bose-Einstein condensation of this exciton state has long been the subject of speculation in various model systems2,3, and examples have been found more recently in optical lattices and two-dimensional materials4-9. Unlike these conventional excitons formed from extended Bloch states4-9, excitonic bound states from intrinsically many-body localized states are rare. Here we show that a spin-orbit-entangled exciton state appears below the Néel temperature of 150 kelvin in NiPS3, an antiferromagnetic van der Waals material. It arises intrinsically from the archetypal many-body states of the Zhang-Rice singlet10,11, and reaches a coherent state assisted by the antiferromagnetic order. Using configuration-interaction theory, we determine the origin of the coherent excitonic excitation to be a transition from a Zhang-Rice triplet to a Zhang-Rice singlet. We combine three spectroscopic tools-resonant inelastic X-ray scattering, photoluminescence and optical absorption-to characterize the exciton and to demonstrate an extremely narrow excitonic linewidth below 50 kelvin. The discovery of the spin-orbit-entangled exciton in antiferromagnetic NiPS3 introduces van der Waals magnets as a platform to study coherent many-body excitons.

3.
Sensors (Basel) ; 24(2)2024 Jan 19.
Article in English | MEDLINE | ID: mdl-38276344

ABSTRACT

Robust and accurate three-dimensional localization is essential for personal navigation, emergency rescue, and worker monitoring in indoor environments. For localization technology to be employed in various applications, it is necessary to reduce infrastructure dependence and limit the maximum error bound. This study aims to accurately estimate the location of various people using smartphones in a building with a cloud platform-based localization system. The proposed technology is modularized in a hierarchical structure to sequentially estimate the floor and location. This system comprises four localization modules: course level detection, fine level detection (FLD), fine location tracking (FLT), and level change detection (LCD). Each module operates organically according to the current user status. The position estimation range is defined as a total of three phases, and an appropriate location estimation module suitable for the corresponding phase operates to estimate the user's location gradually and precisely. When the user's floor is determined by an FLD, the two-dimensional position of the user is estimated by an FLT module that tracks the user's position by comparing the received signal strength indicator vector sequence and radio map. Also, LCD recognizes the user's floor change and converts the user's phase. To verify the proposed technology, various experiments were conducted in a six-story building, and an average accuracy of less than 2 m was obtained.

4.
Korean J Physiol Pharmacol ; 28(4): 295-302, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38926837

ABSTRACT

Walking can have a positive impact on cognitive function in adolescents. This study aimed to compare the effects of walking with sneakers and barefoot on cognitive ability in adolescents. Fifty-nine adolescent male students were included in the study and assigned to the control (n = 20), sneaker (n = 19), and barefoot (n = 20) groups. The barefoot and sneakers group performed a 40-min walking exercise four times a week for 12 weeks during the morning physical activity time, while the control group performed self-study. Electroencephalogram (EEG) and brain activity variables were measured before and after the exercise program. The results showed that after 12 weeks, the barefoot group had a significant decrease in Gamma and H-beta waves and a significant increase in sensorimotor rhythm (SMR) and Alpha waves. Conversely, the control group showed a significant decrease in SMR waves and increase in Theta waves. The sneaker group showed a significant decrease in SMR waves alone. In an eyes-open resting state, the barefoot group showed a significant increase in H-beta, M-beta, SMR, and Alpha waves. The barefoot group also had a significant increase in cognitive speed and concentration and a significant decrease in brain stress. Taken together, barefoot walking can effectively enhance cognitive ability in adolescents, as demonstrated by the significant variation in EEG activity. This research highlights the potential benefits of barefoot walking as a simple and effective form of exercise for enhancing cognitive function in adolescents.

5.
BMC Cardiovasc Disord ; 23(1): 287, 2023 06 07.
Article in English | MEDLINE | ID: mdl-37286945

ABSTRACT

BACKGROUND: Information on electrocardiogram (ECG) has not been quantified in obstructive coronary artery disease (ObCAD), despite the deep learning (DL) algorithm being proposed as an effective diagnostic tool for acute myocardial infarction (AMI). Therefore, this study adopted a DL algorithm to suggest the screening of ObCAD from ECG. METHODS: ECG voltage-time traces within a week from coronary angiography (CAG) were extracted for the patients who received CAG for suspected CAD in a single tertiary hospital from 2008 to 2020. After separating the AMI group, those were classified into ObCAD and non-ObCAD groups based on the CAG results. A DL-based model adopting ResNet was built to extract information from ECG data in the patients with ObCAD relative to those with non-ObCAD, and compared the performance with AMI. Moreover, subgroup analysis was conducted using ECG patterns of computer-assisted ECG interpretation. RESULTS: The DL model demonstrated modest performance in suggesting the probability of ObCAD but excellent performance in detecting AMI. The AUC of the ObCAD model adopting 1D ResNet was 0.693 and 0.923 in detecting AMI. The accuracy, sensitivity, specificity, and F1 score of the DL model for screening ObCAD were 0.638, 0.639, 0.636, and 0.634, respectively, while the figures were up to 0.885, 0.769, 0.921, and 0.758 for detecting AMI, respectively. Subgroup analysis showed that the difference between normal and abnormal/borderline ECG groups was not notable. CONCLUSIONS: ECG-based DL model showed fair performance for assessing ObCAD and it may serve as an adjunct to the pre-test probability in patients with suspected ObCAD during the initial evaluation. With further refinement and evaluation, ECG coupled with the DL algorithm may provide potential front-line screening support in the resource-intensive diagnostic pathways.


Subject(s)
Coronary Artery Disease , Deep Learning , Myocardial Infarction , Humans , Coronary Artery Disease/diagnostic imaging , Myocardial Infarction/diagnosis , Electrocardiography/methods , Algorithms
6.
Urol Int ; 107(6): 591-594, 2023.
Article in English | MEDLINE | ID: mdl-36996784

ABSTRACT

Partial nephrectomy (PN) is a common surgery for small renal masses. The goal is to remove the mass completely while preserving renal function. A precise incision is, therefore, important. However, no specific method for surgical incision in PN exists, although there are several guides for bony structures using three-dimensional (3D) printing methods. Therefore, we tested the 3D printing method to create a surgical guide for PN. We describe the workflow to make the guide, which comprises computed tomography data acquisition and segmentation, incision line creation, surgical guide design, and its use during surgery. The guide was designed with a mesh structure that could be fixed to the renal parenchyma, indicating the projected incision line. During the operation, the 3D-printed surgical guide accurately indicated the incision line, without distortion. An intraoperative sonography was performed to locate the renal mass, which confirmed that the guide was well placed. The mass was completely removed, and the surgical margin was negative. No inflammation or immune reaction occurred during and 1 month after the operation. This surgical guide proved useful during PN for indicating the incision line and was easy to handle, without complications. We, therefore, recommend this tool for PN with improved surgical outcome.


Subject(s)
Kidney Neoplasms , Humans , Kidney Neoplasms/diagnostic imaging , Kidney Neoplasms/surgery , Nephrectomy/methods , Kidney/diagnostic imaging , Kidney/surgery , Tomography, X-Ray Computed , Printing, Three-Dimensional
7.
J Craniofac Surg ; 34(4): 1340-1342, 2023 Jun 01.
Article in English | MEDLINE | ID: mdl-36882913

ABSTRACT

Medial epicanthoplasty is a crucial component in Asian cosmetic eyelid surgery. Conventional surgical methods have mandated wide undermining for the purpose of sufficient release. However, excessive undermining may result in hypertrophic scar or webbing deformities. To minimize undesirable results, the authors are proposing a novel approach. From March 2010 to December 2017, a triangular resection epicanthoplasty was performed in 421 Asian patients. The authors' procedure consists of triangular skin resection, the release of orbicularis oculi muscle and upper half medial epicanthal tendon, and dog ear correction. No complication regarding scarring or webbing was reported. The revision was performed in 18 cases where the patients wanted additional correction. The triangular resection epicanthoplasty offers both optimal results and minimal scar with relative simplicity.


Subject(s)
Blepharoplasty , Cicatrix, Hypertrophic , Humans , Blepharoplasty/methods , Cicatrix, Hypertrophic/prevention & control , Cicatrix, Hypertrophic/surgery , Asian People , Eyelids/surgery , Facial Muscles/surgery , Treatment Outcome
8.
J Orthop Sci ; 2023 Oct 13.
Article in English | MEDLINE | ID: mdl-37839978

ABSTRACT

BACKGROUND: Hindfoot malalignment can cause various foot and ankle problems. For better surgical performance and correction of hindfoot malalignments, reliable intraoperative determination of hindfoot alignment is essential. However, there is no standard method for the intraoperative assessment of hindfoot alignment. We devised an intraoperative modified Méary posteroanterior (IOPPA) view to assess intraoperative hindfoot alignment. This study aimed to compare this intraoperative method with other radiographic hindfoot alignment measurements. METHODS: Thirty-seven patients (47 feet) with various foot and ankle conditions scheduled to undergo surgery were prospectively recruited. Before surgery, the Saltzman, long axial, and modified Méary views were taken in a controlled and standardized fashion. IOPPA views were obtained under simulated weight bearing conditions using C-arm fluoroscopy in the operating room before surgery. The relationship between the IOPPA view and the three radiographic hindfoot alignments was evaluated using Pearson's correlation. RESULTS: The mean hindfoot alignment angle was varus 3.50° (CI, varus 1.91 to 5.08) on the Saltzman view, varus 2.00° (CI, varus 0.60 to 3.39) on the long axial view, varus 0.13° (CI, valgus 1.41 to varus 1.67) on the modified Méary view, and varus 1.32° (CI, valgus 0.02 to varus 2.65) on IOPPA view. The IOPPA view and the three other hindfoot alignment views were found to be significantly correlated (r = 0.60 for the Saltzman view, r = 0.50 for the long axial view, r = 0.71 for the modified Méary view, P < .05). The intraobserver ICC (Intraclass Correlation Coefficient) value was 0.974 and interobserver ICC (Intraclass Correlation Coefficient) value was 0.988 for the IOPPA view (P < .001). CONCLUSION: There was a statistically significant correlation between the IOPPA view and the other three hindfoot alignment views. We also found that interobserver and intraobserver ICC values were excellent. This study proposes that the IOPPA view can be used as a reliable intraoperative assessment tool for hindfoot alignment. LEVEL OF EVIDENCE: Prospective study.

9.
Anal Chem ; 94(27): 9627-9635, 2022 07 12.
Article in English | MEDLINE | ID: mdl-35762898

ABSTRACT

In this study, a homogeneous one-step immunoassay based on switching peptides is presented for the detection of influenza viruses A and B (Inf-A and Inf-B, respectively). The one-step immunoassay represents an immunoassay method that does not involve any washing steps, only treatment of the sample. In this method, fluorescence-labeled switching peptides quantitatively dissociate from the antigen-binding site of immunoglobulin G (IgG). In particular, the one-step immunoassay based on soluble detection antibodies with switching peptides is called a homogeneous one-step immunoassay. The immunoassay developed uses switching peptides labeled with two types of fluorescence dyes (FAM and TAMRA) and detection antibodies labeled with two types of fluorescence quenchers (TQ2 for FAM and TQ3 for TAMRA). The optimal switching peptides for the detection of Inf-A and Inf-B have been selected as L1-peptide and H2-peptide. The interactions between the four kinds of switching peptides and IgG have been analyzed using computational docking simulation and SPR biosensor. The location of labeling for the fluorescence quenchers has been determined based on the distance between the fluorescence dyes of the switching peptides and the fluorescence quenchers, calculated on the basis of the efficiency of fluorescence quenching, using the Förster equation. To demonstrate the feasibility of the one-step immunoassay, binding constants (KD) have been calculated for detection antibodies against Inf-A and Inf-B with target antigens (Inf-A and Inf-B) and switching peptides (L1- and H2-peptides), using an isotherm model. The immunoassay has been demonstrated to be feasible using antigens as well as real samples of Inf-A and Inf-B with a critical cycle number (Ct). The immunoassay has also been compared to other commercially available rapid test kits for Inf-A and Inf-B and found to be far more sensitive for detection of Inf-A and Inf-B over the entire detection range.


Subject(s)
Orthomyxoviridae , Antigens , Fluorescent Dyes/chemistry , Immunoassay/methods , Immunoglobulin G , Peptides/chemistry
10.
Cancer Cell Int ; 22(1): 299, 2022 Oct 01.
Article in English | MEDLINE | ID: mdl-36182900

ABSTRACT

BACKGROUND: Clear cell renal carcinoma is commonly known for its metastasis propensity to outspread to other organs and is asymptomatic in the early stage. Recent studies have shown that deficiencies in CYP11A1 expression can lead to fatal adrenal failure if left untreated and are associated with downstream regulation in various cancer types. However, the molecular mechanisms of CYP11A1 and kidney cancer proliferation remain unclear. METHODS: Normal and renal carcinoma cell lines (HEK293 and Caki-1) were transfected with plasmid encoding CYP11A1 to overexpress the P450scc protein. Cell cycle distribution was investigated using flow cytometry. The expression of proteins related to C-Raf/ERK/JNK/p38 signaling pathways was examined using western blot. RESULTS: We observed that CYP11A1 overexpression suppressed the cyclin B1 and cell-division cycle 2 expression while cyclin-dependent kinases 2 and 4 were unaffected. Cancer cell migration and invasion were suppressed along with epithelial-intermediate metastatic markers Snail and Vimentin. In addition, in CYP11A1-overexpressing Caki-1 cells, cdc2/cyclinB1 was downregulated while the phosphorylation of cdc25c, a G2/M arrest-related upstream signal, was increased. The intrinsic-mitochondrial apoptosis markers were not significantly altered. We also identified that the C-Raf/ERK/JNK/p38 pathway is an important pro-apoptotic mechanism in CYP11A1-overexpressing cell-based models. Our results suggest that CYP11A1 overexpression recovered the disturbed cell cycle arrest distribution in renal carcinoma cell line Caki-1 through G2/M arrest and C-Raf/ERK/JNK pathway. CONCLUSIONS: Our findings may suggest promising new therapeutic targets to suppress kidney cancer proliferation without affecting normal cells, eventually improving the survival of patients with cancer.

11.
BMC Cancer ; 22(1): 331, 2022 Mar 26.
Article in English | MEDLINE | ID: mdl-35346103

ABSTRACT

BACKGROUND: The Laparoscopic Approach to Cervical Cancer trial and Surveillance, Epidemiology, and End Results program database study demonstrated that minimally invasive radical hysterectomy was inferior to abdominal radical hysterectomy in terms of disease recurrence and survival. Among risk factors related to poor prognosis after minimally invasive surgery (MIS), tumour spillage during intracorporeal colpotomy became a significant issue. Thus, we designed this trial to evaluate the efficacy and safety of minimally invasive radical hysterectomy using an endoscopic stapler for early-stage cervical cancer. METHODS: This trial is a prospective, multi-centre, open-label, single-arm, non-inferiority phase II study. The nine organisations will participate in this trial after the approval of the institutional review board. Major eligibility criteria include women aged 20 years or older with cervical cancer stage IB1 squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma according to the revised 2009 FIGO staging system who will undergo type B2 or C hysterectomy by MIS. The primary endpoint is the 4.5-year disease-free survival (DFS) rate between abdominal radical hysterectomy and MIS using an endoscopic stapler. For calculating the sample size, we hypothesised that the 4.5-year DFS rate after MIS using an endoscopic stapler is assumed to be the same after abdominal radical hysterectomy at 90.9%, and the non-inferiority margin was 7.2%. When we consider a three-year accrual and 4.5-year follow-up, at least 13 events must happen, requiring a total of 111 patients assuming a statistical power of 80% and the one-tailed test of 5% significance. A total of 124 patients is needed, considering a drop-out rate of 10%. DISCUSSION: We expect intracorporeal colpotomy using an endoscopic stapler may prevent tumour spillage during MIS for stage IB1 cervical cancer, showing a comparable prognosis with abdominal radical surgery. TRIAL REGISTRATION: ClinicalTrials.gov ; NCT04370496 ; registration date, May 2020.


Subject(s)
Laparoscopy , Robotic Surgical Procedures , Uterine Cervical Neoplasms , Adult , Clinical Trials, Phase II as Topic , Female , Humans , Laparoscopy/adverse effects , Laparoscopy/methods , Multicenter Studies as Topic , Neoplasm Recurrence, Local/pathology , Neoplasm Staging , Prospective Studies , Robotic Surgical Procedures/adverse effects , Robotic Surgical Procedures/methods , Uterine Cervical Neoplasms/pathology , Young Adult
12.
Analyst ; 147(23): 5363-5371, 2022 Nov 21.
Article in English | MEDLINE | ID: mdl-36281825

ABSTRACT

A one-step immunoassay was developed for five types of food-poisoning-related bacteria using a switching peptide and antibodies isolated from unimmunized horse serum. The one-step immunoassay involves mixing samples and reagents in a homogeneous solution without any washing steps. In this work, a one-step immunoassay configuration was developed using isolated antibodies labelled with an organic fluorescence quencher and a switching-peptide labelled with a fluorescent dye. The fluorescence-labelled switching-peptide was bound to the antigen-binding site of the isolated antibodies before binding to the bacteria (no fluorescence signal), and the switching-peptide dissociated from the antibodies as soon as they bound to the bacteria (fluorescence signal turns on). By quantifying the generated fluorescence signal, the one-step immunoassay presented here allows microbial detection without any washing step.


Subject(s)
Antibodies , Fluorescence Resonance Energy Transfer , Immunoassay , Antibodies/chemistry , Peptides/chemistry , Bacteria
13.
Nanotechnology ; 34(1)2022 Oct 12.
Article in English | MEDLINE | ID: mdl-36222531

ABSTRACT

Electronic devices composed of semiconducting two-dimensional (2D) materials and ultrathin 2D metallic electrode materials, accompanying synergistic interactions and extraordinary properties, are becoming highly promising for future flexible and transparent electronic and optoelectronic device applications. Unlike devices with bulk metal electrode and 2D channel materials, devices with ultrathin 2D electrode and 2D channel are susceptible to chemical reactions in both channel and electrode surface due to the high surface to volume ratio of the 2D structures. However, so far, the effect of doping was primary concerned on the channel component, and there is lack of understanding in terms of how to modulate electrical properties of devices by engineering electrical properties of both the metallic electrode and the semiconducting channel. Here, we propose the novel, one-pot doping of the field-effect transistor (FET) based on 2D molybdenum disulfide (MoS2) channel and ultrathin copper sulfide (CuS) electrodes under mild iodine gas environment at room temperature, which simultaneously modulates electrical properties of the 2D MoS2channel and 2D CuS electrode in a facile and cost-effective way. After one-pot iodine doping, effective p-type doping of the channel and electrode was observed, which was shown through decreased off current level, improvedIon/Ioffratio and subthreshold swing value. Our results open up possibility for effectively and conveniently modulating electrical properties of FETs made of various 2D semiconductors and ultrathin contact materials without causing any detrimental damage.

14.
Biotechnol Lett ; 44(9): 1027-1036, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35834094

ABSTRACT

PURPOSE: Peroxidation and reduction of 11S- and 13S-positions on C20 and C22 polyunsaturated fatty acids (PUFAs) by Escherichia coli expressing highly active arachidonate (ARA) 11S-lipoxygenase (11S-LOX) from Enhygromyxa salina with the reducing agent cysteine. RESULTS: The specific activity and catalytic efficiency of ARA 11S-LOX from E. salina were 4.1- and 91-fold higher than those of only reported ARA 11S-LOX from Myxococcus xanthus, respectively. The hydroxy fatty acids (HFAs) obtained by the biotransformation of ARA, eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexanoic acid (DHA) by Escherichia coli expressing 11S-LOX from E. salina in the presence of cysteine were identified as 11S-hydroxyeicosatetraenoic acid (11S-HETE), 11S-hydroxyeicosapentaenoic acid (11S-HEPE), 13S-hydroxydocosapentaenoic acid (13S-HDPA), and 13S-hydroxydocosahexaenoic acid (13S-HDHA), respectively. The recombinant cells converted 3 mM of ARA, EPA, DPA, and DHA into 2.9 mM of 11S-HETE, 2.4 mM 11S-HEPE, 1. 9 mM 13S-HDPA, and 2.2 mM 13S-HDHA in 60, 80, 120, and 120 min, corresponding to productivities of 72.5, 40.4, 18.5, and 22.4 µM min-1 and conversion yields of 96.7, 80.0, 62.3, and 74.6%, respectively. CONCLUSIONS: We report the highest concentrations, conversion yields, and productivities of 11S- and 13S-hydroxy fatty acids from C20- and C22-PUFAs achieved via E. coli expressing highly active E. salina 11S-LOX.


Subject(s)
Escherichia coli , Lipoxygenase , Arachidonate Lipoxygenases/metabolism , Biotransformation , Cysteine/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Fatty Acids , Fatty Acids, Unsaturated/metabolism , Hydroxyeicosatetraenoic Acids , Lipoxygenase/metabolism , Myxococcales
15.
J Korean Med Sci ; 37(31): e244, 2022 Aug 08.
Article in English | MEDLINE | ID: mdl-35942557

ABSTRACT

BACKGROUND: To deliver therapeutics into the brain, it is imperative to overcome the issue of the blood-brain-barrier (BBB). One of the ways to circumvent the BBB is to administer therapeutics directly into the brain parenchyma. To enhance the treatment efficacy for chronic neurodegenerative disorders, repeated administration to the target location is required. However, this increases the number of operations that must be performed. In this study, we developed the IntraBrain Injector (IBI), a new implantable device to repeatedly deliver therapeutics into the brain parenchyma. METHODS: We designed and fabricated IBI with medical grade materials, and evaluated the efficacy and safety of IBI in 9 beagles. The trajectory of IBI to the hippocampus was simulated prior to surgery and the device was implanted using 3D-printed adaptor and surgical guides. Ferumoxytol-labeled mesenchymal stem cells (MSCs) were injected into the hippocampus via IBI, and magnetic resonance images were taken before and after the administration to analyze the accuracy of repeated injection. RESULTS: We compared the planned vs. insertion trajectory of IBI to the hippocampus. With a similarity of 0.990 ± 0.001 (mean ± standard deviation), precise targeting of IBI was confirmed by comparing planned vs. insertion trajectories of IBI. Multiple administrations of ferumoxytol-labeled MSCs into the hippocampus using IBI were both feasible and successful (success rate of 76.7%). Safety of initial IBI implantation, repeated administration of therapeutics, and long-term implantation have all been evaluated in this study. CONCLUSION: Precise and repeated delivery of therapeutics into the brain parenchyma can be done without performing additional surgeries via IBI implantation.


Subject(s)
Ferrosoferric Oxide , Mesenchymal Stem Cells , Animals , Brain/diagnostic imaging , Brain/surgery , Dogs , Humans , Imaging, Three-Dimensional , Magnetic Resonance Imaging/methods
16.
Small ; 17(38): e2102128, 2021 09.
Article in English | MEDLINE | ID: mdl-34390187

ABSTRACT

The trade-off between thermal conductivity (κ) and thermal contact resistance (Rc ) is regarded as a hurdle to develop superior interface materials for thermal management. Here a high-temperature skin softening material to overcome the trade-off relationship, realizing a record-high total thermal conductance (254.92 mW mm-2 K-1 ) for isotropic pad-type interface materials is introduced. A highly conductive hard core is constructed by incorporating Ag flakes and silver nanoparticle-decorated multiwalled carbon nanotubes in thermosetting epoxy (EP). The thin soft skin is composed of filler-embedded thermoplastic poly(ethylene-co-vinyl acetate) (PEVA). The κ (82.8 W m-1 K-1 ) of the PEVA-EP-PEVA interface material is only slightly compromised, compared with that (106.5 W m-1 K-1 ) of the EP core (386 µm). However, the elastic modulus (E = 2.10 GPa) at the skin is significantly smaller than the EP (26.28 GPa), enhancing conformality and decreasing Rc from 108.41 to 78.73 mm2 K W-1 . The thermoplastic skin is further softened at an elevated temperature (100 °C), dramatically decreasing E (0.19 GPa) and Rc (0.17 mm2 K W-1 ) with little change in κ, overcoming the trade-off relationship and enhancing the total thermal conductance by 2030%. The successful heat dissipation and applicability to the continuous manufacturing process demonstrate excellent feasibility as future thermal management materials.


Subject(s)
Metal Nanoparticles , Nanotubes, Carbon , Hot Temperature , Silver , Temperature , Thermal Conductivity
17.
Biotechnol Bioeng ; 118(8): 3094-3104, 2021 08.
Article in English | MEDLINE | ID: mdl-33990936

ABSTRACT

Leukotrienes (LTs) and maresins (MaRs) are human lipid mediators (LMs) involved in immune response and anti-inflammation, respectively. These compounds and their isomers are generated in trace amounts by lipoxygenases (LOXs) in human macrophages and neutrophils. These LMs have been synthesized using nonenvironmentally benign synthetic protocols, which are expensive. 8S- and 15S-LOXs with double dioxygenating activities have previously been reported, whereas 12S-LOX with double dioxygenating activity have not been reported to date. Here, we discovered a wild-type 12S-LOX with double dioxygenating activity from the bacterium Endozoicomonas numazuensis, which produced dihydroxy fatty acids (DiHFAs) as LMs from polyunsaturated fatty acids via double dioxygenation. The enzyme activity for producing DiHFA was approximately 550-fold higher than that of mammalian LOX with double dioxygenating activity. The microbial 12S-LOX converted 3.00 mM of arachidonic acid, eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid to 2.37 mM (797 mg/L) 6-trans-8-cis-12S-epimer of LTB4, 1.59 mM (532 mg/L) 6-trans-8-cis-12S-epimer of LTB5, 1.35 mM (498 mg/L) 10-cis-12-trans-7S-epimer of MaR1n-3 DPA , and 1.54 mM (555 mg/L) 10-cis-12-trans-7S-epimer of MaR1 within 2 h, which were 5.3-, 7.6-, 3.1-, and 5.5-fold higher than those biosynthesized by the previously reported microbial engineered 12S-LOX with double dioxygenating activity, respectively. These findings contribute to the efficient and environmentally friendly biosynthesis of LMs and stimulate physiological study on LMs.


Subject(s)
Arachidonate 12-Lipoxygenase/chemistry , Bacterial Proteins/chemistry , Biocatalysis , Fatty Acids, Unsaturated/chemistry , Gammaproteobacteria/enzymology , Arachidonate 12-Lipoxygenase/genetics , Bacterial Proteins/genetics , Gammaproteobacteria/genetics
18.
Cochrane Database Syst Rev ; 4: CD012654, 2021 Apr 19.
Article in English | MEDLINE | ID: mdl-33871063

ABSTRACT

BACKGROUND: Dietary supplements with ginseng, or ginseng alone, are widely used for a broad range of conditions, including erectile dysfunction. Ginseng is particularly popular in Asian countries. Individual studies assessing its effects are mostly small, of uneven methodological quality and have unclear results. OBJECTIVES: To assess the effects of ginseng on erectile dysfunction. SEARCH METHODS: We conducted systematic searches on multiple electronic databases, including CENTRAL, MEDLINE, Embase, CINAHL, AMED, and loco-regional databases of east Asia, from their inceptions to 30 January 2021 without restrictions on language and publication status. Handsearches included conference proceedings. SELECTION CRITERIA: We included randomized or quasi-randomized controlled trials that evaluated the use of any type of ginseng as a treatment for erectile dysfunction compared to placebo or conventional treatment. DATA COLLECTION AND ANALYSIS: Two authors independently classified studies and three authors independently extracted data and assessed risk of bias in the included studies. We rated the certainty of evidence according to the GRADE approach. MAIN RESULTS: We included nine studies with 587 men with mild to moderate erectile dysfunction, aged from 20 to 70 years old. The studies all compared ginseng to placebo. We found only short-term follow-up data (up to 12 weeks).  Primary outcomes Ginseng appears to have a trivial effect on erectile dysfunction when compared to placebo based on the Erectile Function Domain of the International Index of Erectile Function (IIEF)-15 instrument (scale: 1 to 30, higher scores imply better function; mean difference [MD] 3.52, 95% confidence interval [CI] 1.79 to 5.25; I² = 0%; 3 studies; low certainty evidence) assuming a minimal clinically important difference (MCID) of 4.  Ginseng probably also has a trivial effect on erectile function when compared to placebo based on the IIEF-5 instrument (scale: 1 to 25, higher scores imply better function; MD 2.39, 95% CI 0.89 to 3.88; I² = 0%; 3 studies; moderate certainty evidence) assuming a MCID of 5. Ginseng may have little to no effect on adverse events compared to placebo (risk ratio [RR] 1.45, 95% CI 0.69 to 3.03; I² = 0%; 7 studies; low certainty evidence). Based on 86 adverse events per 1000 men in the placebo group, this would correspond to 39 more adverse events per 1000 (95% CI 27 fewer to 174 more). Secondary outcomes Ginseng may improve men's self-reported ability to have intercourse (RR 2.55, 95% CI 1.76 to 3.69; I² = 23%; 6 studies; low certainty evidence). Based on 207 per 1000 men self-reporting the ability to have intercourse in the placebo group, this would correspond to 321 more men (95% CI 158 more to 558 more) per 1000 self-reporting the ability to have intercourse. Ginseng may have a trivial effect on men's satisfaction with intercourse based on the Intercourse Satisfaction Domain of the IIEF-15 (scale: 0 to 15, higher scores imply greater satisfaction; MD 1.19, 95% CI 0.41 to 1.97; I²=0%; 3 studies; low certainty evidence) based on a MCID of 25% improvement from baseline. It may also have a trivial effect on men's satisfaction with intercourse based on item 5 of the IIEF-5 (scale: 0 to 5, higher scores imply more satisfaction; MD 0.60, 95% CI 0.02 to 1.18; 1 study; low certainty evidence) based on a MCID of 25% improvement from baseline. No study reported quality of life as an outcome. We found no trial evidence to inform comparisons to other treatments for erectile dysfunction, such as phosphodiesterase-5 inhibitors. We were unable to conduct any predefined subgroup analyses. AUTHORS' CONCLUSIONS: Based on mostly low certainty evidence, ginseng may only have trivial effects on erectile function or satisfaction with intercourse compared to placebo when assessed using validated instruments. Ginseng may improve men's self-reported ability to have intercourse. It may have little to no effect on adverse events. We found no trial evidence comparing ginseng to other agents with a more established role in treating erectile dysfunction, such as phosphodiesterase-5 inhibitors.


Subject(s)
Erectile Dysfunction/drug therapy , Panax , Phytotherapy/methods , Adult , Aged , Coitus , Confidence Intervals , Humans , Male , Middle Aged , Patient Satisfaction , Placebos/therapeutic use , Randomized Controlled Trials as Topic , Young Adult
19.
J Enzyme Inhib Med Chem ; 36(1): 831-846, 2021 Dec.
Article in English | MEDLINE | ID: mdl-33752569

ABSTRACT

Small molecule modulators of mitochondrial function have been attracted much attention in recent years due to their potential therapeutic applications for neurodegenerative diseases. The mitochondrial translocator protein (TSPO) is a promising target for such compounds, given its involvement in the formation of the mitochondrial permeability transition pore in response to mitochondrial stress. In this study, we performed a ligand-based pharmacophore design and virtual screening, and identified a potent hit compound, 7 (VH34) as a TSPO ligand. After validating its biological activity against amyloid-ß (Aß) induced mitochondrial dysfunction and in acute and transgenic Alzheimer's disease (AD) model mice, we developed a library of analogs, and we found two most active compounds, 31 and 44, which restored the mitochondrial membrane potential, ATP production, and cell viability under Aß-induced mitochondrial toxicity. These compounds recovered learning and memory function in acute AD model mice with improved pharmacokinetic properties.


Subject(s)
Alzheimer Disease/drug therapy , Mitochondria/drug effects , Neuroprotective Agents/pharmacology , Protein Aggregation, Pathological/drug therapy , Small Molecule Libraries/pharmacology , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Amyloid beta-Peptides/antagonists & inhibitors , Amyloid beta-Peptides/metabolism , Animals , Cell Survival/drug effects , Cells, Cultured , Disease Models, Animal , Drug Evaluation, Preclinical , Humans , Ligands , Mice , Mitochondria/metabolism , Molecular Structure , Neuroprotective Agents/chemical synthesis , Neuroprotective Agents/chemistry , Protein Aggregation, Pathological/metabolism , Protein Aggregation, Pathological/pathology , Small Molecule Libraries/chemical synthesis , Small Molecule Libraries/chemistry , Transcriptional Regulator ERG/antagonists & inhibitors , Transcriptional Regulator ERG/metabolism
20.
Phys Rev Lett ; 125(2): 027202, 2020 Jul 10.
Article in English | MEDLINE | ID: mdl-32701352

ABSTRACT

Noncollinear magnetic order arises for various reasons in several magnetic systems and exhibits interesting spin dynamics. Despite its ubiquitous presence, little is known of how magnons, otherwise stable quasiparticles, decay in these systems, particularly in metallic magnets. Using inelastic neutron scattering, we examine the magnetic excitation spectra in a metallic noncollinear antiferromagnet CrB_{2}, in which Cr atoms form a triangular lattice and display incommensurate magnetic order. Our data show intrinsic magnon damping and continuumlike excitations that cannot be explained by linear spin wave theory. The intrinsic magnon linewidth Γ(q,E_{q}) shows very unusual momentum dependence, which our analysis shows to originate from the combination of two-magnon decay and the Stoner continuum. By comparing the theoretical predictions with the experiments, we identify where in the momentum and energy space one of the two factors becomes more dominant. Our work constitutes a rare comprehensive study of the spin dynamics in metallic noncollinear antiferromagnets. It reveals, for the first time, definite experimental evidence of the higher-order effects in metallic antiferromagnets.

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