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1.
Nature ; 610(7930): 67-73, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36131017

RESUMEN

The high volatility of the price of cobalt and the geopolitical limitations of cobalt mining have made the elimination of Co a pressing need for the automotive industry1. Owing to their high energy density and low-cost advantages, high-Ni and low-Co or Co-free (zero-Co) layered cathodes have become the most promising cathodes for next-generation lithium-ion batteries2,3. However, current high-Ni cathode materials, without exception, suffer severely from their intrinsic thermal and chemo-mechanical instabilities and insufficient cycle life. Here, by using a new compositionally complex (high-entropy) doping strategy, we successfully fabricate a high-Ni, zero-Co layered cathode that has extremely high thermal and cycling stability. Combining X-ray diffraction, transmission electron microscopy and nanotomography, we find that the cathode exhibits nearly zero volumetric change over a wide electrochemical window, resulting in greatly reduced lattice defects and local strain-induced cracks. In-situ heating experiments reveal that the thermal stability of the new cathode is significantly improved, reaching the level of the ultra-stable NMC-532. Owing to the considerably increased thermal stability and the zero volumetric change, it exhibits greatly improved capacity retention. This work, by resolving the long-standing safety and stability concerns for high-Ni, zero-Co cathode materials, offers a commercially viable cathode for safe, long-life lithium-ion batteries and a universal strategy for suppressing strain and phase transformation in intercalation electrodes.

2.
Proc Natl Acad Sci U S A ; 119(15): e2119429119, 2022 04 12.
Artículo en Inglés | MEDLINE | ID: mdl-35377791

RESUMEN

Charge density waves (CDWs) have been observed in nearly all families of copper-oxide superconductors. But the behavior of these phases across different families has been perplexing. In La-based cuprates, the CDW wavevector is an increasing function of doping, exhibiting the so-called Yamada behavior, while in Y- and Bi-based materials the behavior is the opposite. Here, we report a combined resonant soft X-ray scattering (RSXS) and neutron scattering study of charge and spin density waves in isotopically enriched La1.8−xEu0.2SrxCuO4 over a range of doping 0.07≤x≤0.20. We find that the CDW amplitude is temperature independent and develops well above experimentally accessible temperatures. Further, the CDW wavevector shows a nonmonotonic temperature dependence, exhibiting Yamada behavior at low temperature with a sudden change occurring near the spin ordering temperature. We describe these observations using a Landau­Ginzburg theory for an incommensurate CDW in a metallic system with a finite charge compressibility and spin-CDW coupling. Extrapolating to high temperature, where the CDW amplitude is small and spin order is absent, our analysis predicts a decreasing wavevector with doping, similar to Y and Bi cuprates. Our study suggests that CDW order in all families of cuprates forms by a common mechanism.

3.
Small ; : e2406249, 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39221532

RESUMEN

Aqueous Zn-ion batteries (AZIBs) are promising energy-storage devices owing to their exceptional safety, long cycle life, simple production, and high storage capacity. Manganese oxides are considered potential cathode materials for AZIBs, primarily because of their safety, low cost, simple synthesis, and high storage capacity. However, MnO2-based cathodes tend to deteriorate structurally during long-term cycling, which reduces their reversible capacity. In this study, an advanced α-MnO2@SnO2 nanocomposite via facile hydrothermal synthesis is developed. The synergistic effects of lattice disorder and increased electron conductivity in the α-MnO2@SnO2 nanocomposite mitigate structural degradation and enhance the overall electrochemical performance. The nanocomposite exhibits a high reversible capacity of 347 mAh g-1 at a current density of 100 mA g-1 after 50 cycles. Furthermore, it exhibits excellent rate performance and stable capacity even after 1000 cycles, maintaining a capacity of 78 mAh g-1 at a high current density of 5 A g-1. This excellent electrochemical performance is attributed to the reversible Zn intercalation in α-MnO2@SnO2 nanocomposites due to the increased structural stability and fast ion/electron exchange caused by the distortion of the tunnel structure, on the basis of various ex situ experiments, density functional theory calculations, and electrochemical characterizations.

4.
Sensors (Basel) ; 24(20)2024 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-39460145

RESUMEN

Simultaneous localization and mapping, a critical technology for enabling the autonomous driving of vehicles and mobile robots, increasingly incorporates multi-sensor configurations. Inertial measurement units (IMUs), known for their ability to measure acceleration and angular velocity, are widely utilized for motion estimation due to their cost efficiency. However, the inherent noise in IMU measurements necessitates the integration of additional sensors to facilitate spatial understanding for mapping. Visual-inertial odometry (VIO) is a prominent approach that combines cameras with IMUs, offering high spatial resolution while maintaining cost-effectiveness. In this paper, we introduce our uncertainty-aware depth network (UD-Net), which is designed to estimate both depth and uncertainty maps. We propose a novel loss function for the training of UD-Net, and unreliable depth values are filtered out to improve VIO performance based on the uncertainty maps. Experiments were conducted on the KITTI dataset and our custom dataset acquired from various driving scenarios. Experimental results demonstrated that the proposed VIO algorithm based on UD-Net outperforms previous methods with a significant margin.

5.
Nano Lett ; 23(5): 1743-1751, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36811529

RESUMEN

P2-Na0.67Ni0.33Mn0.67O2 represents a promising cathode for Na-ion batteries, but it suffers from severe structural degradation upon storing in a humid atmosphere and cycling at a high cutoff voltage. Here we propose an in situ construction to achieve simultaneous material synthesis and Mg/Sn cosubstitution of Na0.67Ni0.33Mn0.67O2 via one-pot solid-state sintering. The materials exhibit superior structural reversibility and moisture insensitivity. In-operando XRD reveals an essential correlation between cycling stability and phase reversibility, whereas Mg substitution suppressed the P2-O2 phase transition by forming a new Z phase, and Mg/Sn cosubstitution enhanced the P2-Z transition reversibility benefiting from strong Sn-O bonds. DFT calculations disclosed high chemical tolerance to moisture, as the adsorption energy to H2O was lower than that of the pure Na0.67Ni0.33Mn0.67O2. A representative Na0.67Ni0.23Mg0.1Mn0.65Sn0.02O2 cathode exhibits high reversible capacities of 123 mAh g-1 (10 mA g-1), 110 mAh g-1 (200 mA g-1), and 100 mAh g-1 (500 mA g-1) and a high capacity retention of 80% (500 mA g-1, 500 cycles).

6.
Genome Res ; 30(5): 768-775, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32327447

RESUMEN

Genome editing has been revolutionized by the CRISPR-Cas9 system. CRISPR-Cas9 is composed of single-molecular guide RNA (sgRNA) and a proteinaceous Cas9 nuclease, which recognizes a specific target sequence and a protospacer adjacent motif (PAM) sequence and, subsequently, cleaves the targeted DNA sequence. This CRISPR-Cas9 system has been used as an efficient negative-selection tool to cleave unedited or unchanged target DNAs during site-specific mutagenesis and, consequently, obtain microbial cells with desired mutations. This study aimed to investigate the genome editing efficiency of the CRISPR-Cas9 system for in vivo oligonucleotide-directed mutagenesis in bacteria. This system successfully introduced two- to four-base mutations in galK in Escherichia coli with high editing efficiencies (81%-86%). However, single-point mutations (T504A or C578A) were rarely introduced with very low editing efficiencies (<3%), probably owing to mismatch tolerance. To resolve this issue, we designed one- or two-base mismatches in the sgRNA sequence to recognize target sequences in galK in E. coli A single-point nucleotide mutation (T504A or C578A in the galK gene) was successfully introduced in 36%-95% of negatively selected E. coli cells using single-base mismatched sgRNAs. Sixteen targets were randomly selected through genome-wide single-base editing experiments using mismatched sgRNAs. Consequently, out of 48 desired single-base mutations, 25 single bases were successfully edited, using mismatched sgRNAs. Finally, applicable design rules for target-mismatched sgRNAs were provided for single-nucleotide editing in microbial genomes.


Asunto(s)
Sistemas CRISPR-Cas , Edición Génica/métodos , Disparidad de Par Base , Proteína 9 Asociada a CRISPR/genética , Escherichia coli/genética , Genoma Bacteriano , Mutagénesis , Mutación , Plásmidos/genética , ARN/química
7.
BMC Musculoskelet Disord ; 24(1): 540, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37393227

RESUMEN

BACKGROUND: During the coronavirus disease (COVID-19) pandemic, the amount of moderate- to high-intensity physical activity significantly decreased. Therefore, the epidemiology of musculoskeletal diseases could possibly have changed. We assessed changes in the incidence of and variance in non-traumatic orthopedic diseases before and after the COVID-19 pandemic in Korea. METHODS: This study included data from the Korea National Health Insurance Service, which covers the entire Korean population (approximately 50 million), from January 2018 to June 2021. Using International Classification of Diseases, Tenth Revision codes, 12 common orthopedic diseases were evaluated, including cervical disc disorders, lumbar disc disorders, forward head posture, myofascial pain syndrome, carpal tunnel syndrome, tennis elbow, frozen shoulder, rheumatoid arthritis, gout, hip fracture, distal radius fracture, and spine fracture diseases. "Pre-COVID-19" was the period until February 2020, and "COVID-19 pandemic period" was the period starting March 2020. Differences in the mean incidence and variance of diseases before and during the COVID-19 pandemic were compared. RESULTS: In most cases, the incidence of orthopedic diseases decreased at the beginning of the pandemic and then increased thereafter. Among the 12 diseases, the incidence of three diseases showed a statistically significant change. The incidence of myofascial pain syndrome (P < 0.001) was lower during the COVID-19 pandemic than during the pre-COVID-19 period. The incidences of frozen shoulder (P < 0.001) and gout (P = 0.043) were higher during the COVID-19 pandemic than during the pre-COVID-19 period. However, no statistical difference in disease variations was observed between the two periods. CONCLUSIONS: The incidence of orthopedic diseases varied during the COVID-19 pandemic among the Korean population. Although the incidence of myofascial pain syndrome was lower, that of frozen shoulder and gout was higher during the COVID-19 pandemic than during the pre-COVID-19 period. No disease variations during the COVID-19 pandemic were found.


Asunto(s)
Bursitis , COVID-19 , Fibromialgia , Fracturas Óseas , Gota , Degeneración del Disco Intervertebral , Enfermedades Musculoesqueléticas , Humanos , Estudios Retrospectivos , Incidencia , Pandemias , COVID-19/epidemiología , República de Corea/epidemiología
8.
J Korean Med Sci ; 38(23): e176, 2023 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-37309695

RESUMEN

BACKGROUND: Exercise is an important method to control the progression of diabetes. Since diabetes compromises immune function and increases the risk of infectious diseases, we hypothesized that exercise may affect the risk of infection by its immunoprotective effects. However, population-based cohort studies regarding the association between exercise and the risk of infection are limited, especially regarding changes in exercise frequency. The aim of this study was to determine the association between the change in exercise frequency and the risk of infection among patients with newly diagnosed diabetes. METHODS: Data of 10,023 patients with newly diagnosed diabetes were extracted from the Korean National Health Insurance Service-Health Screening Cohort. Self-reported questionnaires for moderate-to-vigorous physical activity (MVPA) were used to classify changes in exercise frequency between two consecutive two-year periods of health screenings (2009-2010 and 2011-2012). The association between changes in exercise frequency and the risk of infection was evaluated using multivariable Cox proportional-hazards regression. RESULTS: Compared with engaging in ≥ 5 times of MVPA/week during both periods, a radical decrease in MVPA (from ≥ 5 times of MVPA/week to physical inactivity) was associated with a higher risk of pneumonia (adjusted hazard ratio [aHR], 1.60; 95% confidence interval [CI], 1.03-2.48) and upper respiratory tract infection (aHR, 1.15; 95% CI, 1.01-1.31). In addition, a reduction of MVPA from ≥ 5 to < 5 times of MVPA/week was associated with a higher risk of pneumonia (aHR, 1.52; 95% CI, 1.02-2.27), whereas the risk of upper respiratory tract infection was not higher. CONCLUSION: Among patients with newly diagnosed diabetes, a reduction in exercise frequency was related to an increase in the risk of pneumonia. For patients with diabetes, a modest level of physical activity may need to be maintained to reduce the risk of pneumonia.


Asunto(s)
Diabetes Mellitus , Ejercicio Físico , Infecciones , Humanos , Pueblo Asiatico , Estudios de Cohortes , Programas Nacionales de Salud , Infecciones/epidemiología
9.
Lasers Med Sci ; 38(1): 272, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37991524

RESUMEN

With an increasing demand for noninvasive skin rejuvenation techniques, several light-based devices have been introduced. Due to its ability to deliver thermal energy from the superficial to deeper levels of the dermis, a combined triple-wavelength laser (755 nm, 810 nm, and 1064 nm) can be used for skin rejuvenation. The objective of this study was to assess the effectiveness and safety of a combined triple-wavelength laser for skin rejuvenation. A total of 28 female patients seeking skin rejuvenation treatment were included. All patients underwent five consecutive treatment sessions at a two-week interval. Clinical improvement of aging-related cutaneous change was noted by the treating dermatologists and patients. Biopsies were performed on the faces of consenting patients before and two weeks after the final treatment. Significant clinical improvements were observed by both patients and evaluating dermatologists. Based on the patient satisfaction questionnaire, 78% of patients reported a self-assessed improvement of more than 25%. Additionally, 86% of patients showed an improvement of more than 25% on objective assessment by dermatologists. Histopathological findings revealed increased collagen and elastic bundles throughout the dermis. Except for transient pain during treatment, no serious adverse effects were reported. The findings of this study suggest that the combined triple-wavelength laser may be an effective and safe nonablative option for skin rejuvenation.


Asunto(s)
Rejuvenecimiento , Piel , Humanos , Femenino , Administración Cutánea , Biopsia , Rayos Láser
10.
Sensors (Basel) ; 23(24)2023 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-38139714

RESUMEN

Monocular depth estimation is a task aimed at predicting pixel-level distances from a single RGB image. This task holds significance in various applications including autonomous driving and robotics. In particular, the recognition of surrounding environments is important to avoid collisions during autonomous parking. Fisheye cameras are adequate to acquire visual information from a wide field of view, reducing blind spots and preventing potential collisions. While there have been increasing demands for fisheye cameras in visual-recognition systems, existing research on depth estimation has primarily focused on pinhole camera images. Moreover, depth estimation from fisheye images poses additional challenges due to strong distortion and the lack of public datasets. In this work, we propose a novel underground parking lot dataset called JBNU-Depth360, which consists of fisheye camera images and their corresponding LiDAR projections. Our proposed dataset was composed of 4221 pairs of fisheye images and their corresponding LiDAR point clouds, which were obtained from six driving sequences. Furthermore, we employed a knowledge-distillation technique to improve the performance of the state-of-the-art depth-estimation models. The teacher-student learning framework allows the neural network to leverage the information in dense depth predictions and sparse LiDAR projections. Experiments were conducted on the KITTI-360 and JBNU-Depth360 datasets for analyzing the performance of existing depth-estimation models on fisheye camera images. By utilizing the self-distillation technique, the AbsRel and SILog error metrics were reduced by 1.81% and 1.55% on the JBNU-Depth360 dataset. The experimental results demonstrated that the self-distillation technique is beneficial to improve the performance of depth-estimation models.

11.
Angew Chem Int Ed Engl ; 62(28): e202304628, 2023 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-37139583

RESUMEN

Deep sodium extraction/insertion of sodium cathodes usually causes undesired Jahn-Teller distortion and phase transition, both of which will reduce structural stability and lead to poor long-cycle reliability. Here we report a zero-strain P2- Na2/3 Li1/6 Co1/6 Mn2/3 O2 cathode, in which the lithium/cobalt substitution contributes to reinforcing the host structure by reducing the Mn3+ /Mn4+ redox, mitigating the Jahn-Teller distortion, and minimizing the lattice change. 94.5 % of Na+ in the unit structure can be reversibly cycled with a charge cut-off voltage of 4.5 V (vs. Na+ /Na). Impressively, a solid-solution reaction without phase transitions is realized upon deep sodium (de)intercalation, which poses a minimal volume deviation of 0.53 %. It attains a high discharge capacity of 178 mAh g-1 , a high energy density of 534 Wh kg-1 , and excellent capacity retention of 95.8 % at 1 C after 250 cycles.

12.
Inorg Chem ; 61(4): 1961-1972, 2022 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-35029978

RESUMEN

Understanding the electronic structure and chemical bonding of transition metal complexes is important for improving the function of molecular photosensitizers and catalysts. We have utilized X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS) at the Fe L3 edge to investigate the electronic structure of two Fe N-heterocyclic carbene complexes with similar chemical structures but different steric effects and contrasting excited-state dynamics: [Fe(bmip)2]2+ and [Fe(btbip)2]2+, bmip = 2,6-bis(3-methyl-imidazole-1-ylidine)pyridine and btbip = 2,6-bis(3-tert-butyl-imidazole-1-ylidene)pyridine. In combination with charge transfer multiplet and ab initio calculations, we quantified how changes in Fe-carbene bond length due to steric effects modify the metal-ligand bonding, including σ/π donation and π back-donation. We find that σ donation is significantly stronger in [Fe(bmip)2]2+, whereas the π back-donation is similar in both complexes. The resulting stronger ligand field and nephelauxetic effect in [Fe(bmip)2]2+ lead to approximately 1 eV destabilization of the quintet metal-centered 5T2g excited state compared to [Fe(btbip)2]2+, providing an explanation for the absence of a photoinduced 5T2g population and a longer metal-to-ligand charge-transfer excited-state lifetime in [Fe(bmip)2]2+. This work demonstrates how combined modeling of XAS and RIXS spectra can be utilized to understand the electronic structure of transition metal complexes governed by correlated electrons and donation/back-donation interactions.

13.
Environ Res ; 212(Pt C): 113392, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35525295

RESUMEN

Air pollution and meteorological factors can exacerbate susceptibility to respiratory viral infections. To establish appropriate prevention and intervention strategies, it is important to determine whether these factors affect the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, this study examined the effects of sunshine, temperature, wind, and air pollutants including sulfur dioxide (SO2), carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), particulate matter ≤2.5 µm (PM2.5), and particulate matter ≤10 µm (PM10) on the age-standardized incidence ratio of coronavirus disease (COVID-19) in South Korea between January 2020 and April 2020. Propensity score weighting was used to randomly select observations into groups according to whether the case was cluster-related, to reduce selection bias. Multivariable logistic regression analyses were used to identify factors associated with COVID-19 incidence. Age 60 years or over (odds ratio [OR], 1.29; 95% CI, 1.24-1.35), exposure to ambient air pollutants, especially SO2 (OR, 5.19; 95% CI, 1.13-23.9) and CO (OR, 1.17; 95% CI, 1.07-1.27), and non-cluster infection (OR, 1.28; 95% CI, 1.24-1.32) were associated with SARS-CoV-2 infection. To manage and control COVID-19 effectively, further studies are warranted to confirm these findings and to develop appropriate guidelines to minimize SARS-CoV-2 transmission.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , COVID-19 , Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/toxicidad , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , COVID-19/epidemiología , Humanos , Incidencia , Conceptos Meteorológicos , Persona de Mediana Edad , Dióxido de Nitrógeno/análisis , Dióxido de Nitrógeno/toxicidad , Ozono/análisis , Ozono/toxicidad , Material Particulado/análisis , Material Particulado/toxicidad , República de Corea/epidemiología , SARS-CoV-2 , Dióxido de Azufre/análisis , Dióxido de Azufre/toxicidad
14.
Lasers Med Sci ; 37(2): 1203-1208, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34250567

RESUMEN

A facial pore is an empty funnel-shaped structure filled with cornified cylindrical plugs that can be cosmetically bothersome to some patients. In the previous report, the new unipolar radiofrequency (RF) device with a vacuum showed excellent skin tightening and patient satisfaction with improved pores. This study aims to confirm the treatment's efficacy with the new unipolar RF device on facial dilated pores by measuring quantitative sebum production differences and doing a histologic examination of pore size. Twelve patients who visited the dermatologic clinic without other underlying inflammatory facial skin diseases were included, regardless of the patient's age or sex. All patients received five successive treatments at 2-week intervals. We assessed all changes in sebum production levels, melanin index, erythema index before and after treatment, along with overall improvement (reduction of pore size, skin tone, skin texture, and skin laxity). In the five patients who agreed in advance, a biopsy of the pore lesion was taken before and 1 month after the last treatment with hematoxylin and eosin (H&E) staining, Masson's trichrome (M-T) staining, and Victoria blue staining. We observed a significant reduction of sebum production and melanin index after using the new unipolar RF device with a vacuum (sebum production, p = 0.011; MI, p = 0.004). In evaluating patient satisfaction for four categories, the patients showed a moderate to the excellent improvement of more than 50% in their condition except for skin tones. The average pore size decreased by 41.7% in the histological examination, from 64.98 to 37.86 µm. Additionally, we observed an overall decreased sebaceous gland in the dermis and the proliferation of dermal collagen fiber. The number of elastic bundles in the D-E junction was increased after treatment. The nonablative unipolar RF devices with a vacuum can improve dilated pores with a dual mechanism (collagen regeneration and reduction of sebum production), with much less pain than other RF devices.


Asunto(s)
Técnicas Cosméticas , Envejecimiento de la Piel , Cara , Humanos , Satisfacción del Paciente , Ondas de Radio , Piel
15.
Lasers Med Sci ; 37(1): 531-536, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33730239

RESUMEN

Intense pulsed light (IPL) devices have been used in acne treatment in combination with conventional topical and oral medications. This study aimed to evaluate the efficacy and safety of IPL treatment using a dual-band filter (400-600 nm and 800-1200 nm) in facial acne vulgaris treatment. Twenty-three acne vulgaris patients were enrolled in this study. The patients were treated on both sides of the face. The treatments were performed in 2-week intervals for a total of five sessions. The final visit for the clinical evaluation was 2 weeks after the fifth treatment session. The mean number of papules, pustules, and comedones, and the melanin index, was significantly decreased at the final visit. However, sebum production and the erythema index showed no statistically significant differences after treatment. IPL treatment using a dual-band filter can be an alternative for patients who are unfit for systemic acne medication. It can also be used with conventional acne treatment for better treatment results.


Asunto(s)
Acné Vulgar , Fotoquimioterapia , Acné Vulgar/tratamiento farmacológico , Eritema , Cara , Humanos , Resultado del Tratamiento
16.
BMC Microbiol ; 21(1): 332, 2021 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-34872501

RESUMEN

BACKGROUND: Microorganisms can prioritize the uptake of different sugars depending on their metabolic needs and preferences. When both D-glucose and D-xylose are present in growth media, E. coli cells typically consume D-glucose first and then D-xylose. Similarly, when E. coli BL21(DE3) is provided with both D-glucose and D-xylose under anaerobic conditions, glucose is consumed first, whereas D-xylose is consumed very slowly. RESULTS: When BL21(DE3) was adaptively evolved via subculture, the consumption rate of D-xylose increased gradually. Strains JH001 and JH019, whose D-xylose consumption rate was faster, were isolated after subculture. Genome analysis of the JH001 and JH019 strains revealed that C91A (Q31K) and C740T (A247V) missense mutations in the xylR gene (which encodes the XylR transcriptional activator), respectively, controlled the expression of the xyl operon. RT-qPCR analyses demonstrated that the XylR mutation caused a 10.9-fold and 3.5-fold increase in the expression of the xylA (xylose isomerase) and xylF (xylose transporter) genes, respectively, in the adaptively evolved JH001 and JH019 strains. A C91A adaptive mutation was introduced into a new BL21(DE3) background via single-base genome editing, resulting in immediate and efficient D-xylose consumption. CONCLUSIONS: Anaerobically-adapted BL21(DE3) cells were obtained through short-term adaptive evolution and xylR mutations responsible for faster D-xylose consumption were identified, which may aid in the improvement of microbial fermentation technology.


Asunto(s)
Proteínas de Escherichia coli/genética , Escherichia coli/metabolismo , Factores de Transcripción/genética , Xilosa/metabolismo , Isomerasas Aldosa-Cetosa/genética , Anaerobiosis , Escherichia coli/genética , Escherichia coli/crecimiento & desarrollo , Proteínas de Escherichia coli/metabolismo , Fermentación , Edición Génica , Regulación Bacteriana de la Expresión Génica , Genoma Bacteriano/genética , Mutación , Operón , Proteínas/genética , Factores de Transcripción/metabolismo
17.
Nanotechnology ; 32(19): 195206, 2021 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-33620035

RESUMEN

Vertically aligned two-dimensional (2D) molybdenum disulfide nanoflowers (MoS2 NFs) have drawn considerable attention as a novel functional material with potential for next-generation applications owing to their inherently distinctive structure and extraordinary properties. We report a simple metal organic chemical vapor deposition (MOCVD) method that can grow high crystal quality, large-scale and highly homogeneous MoS2 NFs through precisely controlling the partial pressure ratio of H2S reaction gas, P SR, to Mo(CO)6 precursor, P MoP, at a substrate temperature of 250 °C. We investigate microscopically and spectroscopically that the S/Mo ratio, optical properties and orientation of the grown MoS2 NFs can be controlled by adjusting the partial pressure ratio, P SR/P MoP. It is also shown that the low temperature MOCVD (LT-MOCVD) growth method can regulate the petal size of MoS2 NFs through the growth time, thereby controlling photoluminescence intensity. More importantly, the MoS2 NFs/GaAs heterojunction flexible solar cell exhibiting a power conversion efficiency of ∼1.3% under air mass 1.5 G illumination demonstrates the utility of the LT-MOCVD method that enables the direct growth of MoS2 NFs on the flexible devices. Our work can pave the way for practical, easy-to-fabricate 2D materials integrated flexible devices in optical and photonic applications.

18.
Dermatol Ther ; 34(3): e14918, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33631028

RESUMEN

Acne is a common skin disease that occurs in pilosebaceous units and is often prevalent in adolescence. There are many acne treatments, but they are associated with side effects, such as antibiotic resistance, teratogenicity, and irritation. Therefore, it is necessary to develop a more effective and safe alternative treatment for managing acne in patients of all ages. This study aimed to confirm the effect of gold photothermal therapy for acne. About 12 patients who visited the dermatologic clinic with moderate to severe acne vulgaris were included in the study, regardless of age or sex. All patients received three successive treatments at 1- to 2-week intervals with a photopneumatic device after applying the contents of a gold nanoparticle ample to the skin. Changes in the number of papules, pustules, and comedones before and after treatment, along with the overall improvement, were assessed. In four patients, a biopsy was taken before and 1 month after the last treatment. Significant reductions in acne lesions were observed after the use of gold photothermal therapy (papules, P = .001; pustules, P < .001; and comedones, P = .001). As noted in the Physician Global Assessment, the patients showed an average improvement of more than 50% in their condition. In the histopathological findings, a decrease in inflammatory cell infiltration and fibrotic changes of the dermis were observed after gold photothermal therapy. Gold photothermal therapy showed significant clinical and histological improvements in acne vulgaris in Asians without serious adverse effects.


Asunto(s)
Acné Vulgar , Nanopartículas del Metal , Acné Vulgar/diagnóstico , Acné Vulgar/terapia , Adolescente , Pueblo Asiatico , Oro , Humanos , Terapia Fototérmica , Resultado del Tratamiento
19.
J Cosmet Laser Ther ; 23(7-8): 170-175, 2021 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-35243964

RESUMEN

Radiofrequency (RF) has been widely used as a noninvasive technique for skin tightening and rejuvenation. Moiré is a type of interference pattern corresponding to the shape of the face. We aimed to objectively evaluate the effect of RF on facial skin laxity using moiré. Ten subjects participated and were treated with a monopolar RF on the face. Clinical photographs and moiré images were obtained at the baseline and after treatment. The periorbital angle from the upper third of the face, zygomatic length ratio (L1/L2), angle from the middle third, perioral perpendicular length, and angle from the lower third were analyzed. After one session of RF treatment, the mean zygomatic length ratio (L1/L2) from the middle third of the face significantly increased in the 4th week (by 49.68%, P = .047). The L1/L2 ratio increased to nearly one, which were not significant after 8 weeks. The mean perioral perpendicular length decreased to 282.25 ± 84.069 pixels (px) after 4 weeks, and to 281.38 ± 76.03 px after 24 weeks; these differences were statistically significant. The parameters of zygomatic length ratio and perioral perpendicular length extracted from illuminated moiré images can be useful for objectively assessing various facial tightening treatments in clinical settings.


Asunto(s)
Técnicas Cosméticas , Terapia por Radiofrecuencia , Envejecimiento de la Piel , Técnicas Cosméticas/efectos adversos , Humanos , Topografía de Moiré , Rejuvenecimiento
20.
Sensors (Basel) ; 21(19)2021 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-34640993

RESUMEN

Human-robot interaction has received a lot of attention as collaborative robots became widely utilized in many industrial fields. Among techniques for human-robot interaction, collision identification is an indispensable element in collaborative robots to prevent fatal accidents. This paper proposes a deep learning method for identifying external collisions in 6-DoF articulated robots. The proposed method expands the idea of CollisionNet, which was previously proposed for collision detection, to identify the locations of external forces. The key contribution of this paper is uncertainty-aware knowledge distillation for improving the accuracy of a deep neural network. Sample-level uncertainties are estimated from a teacher network, and larger penalties are imposed for uncertain samples during the training of a student network. Experiments demonstrate that the proposed method is effective for improving the performance of collision identification.


Asunto(s)
Robótica , Destilación , Humanos , Redes Neurales de la Computación , Incertidumbre
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