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1.
Environ Geochem Health ; 46(8): 289, 2024 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-38970698

RESUMO

Low molecular weight organic acids (LMWOAs) are important soil components and play a key role in regulating the geochemical behavior of heavy metal(loid)s. Biochar (BC) is a commonly used amendment that could change LMWOAs in soil. Here, four LMWOAs of oxalic acid (OA), tartaric acid (TA), malic acid (MA), and citric acid (CA) were evaluated for their roles in changing Cd and SB desorption behavior in contaminated soil with (S1-BC) or without BC (S1) produced from Paulownia biowaste. The results showed that OA, TA, MA, and CA reduced soil pH with rising concentrations, and biochar partially offset the pH reduction by LMWOAs. The LMWOAs reduced Cd desorption from the soil at low concentrations but increased Cd desorption at high concentrations, and CA was the most powerful in this regard. The LMWOAs had a similar effect on Sb desorption, and CA was the most effective species of LMWOAs. Adding BC to the soil affects Cd and Sb dynamics by reducing the Cd desorption but increasing Sb desorption from the soil and increasing the distribution coefficient (Kd) values of Cd but lowering the Kd values of Sb. This study helped understand the effects of LMWOAs on the geochemical behavior of Cd and Sb in the presence of biochar, as well as the potential risks of biochar amendment in enhancing Sb desorption from contaminated soil.


Assuntos
Carvão Vegetal , Metais Pesados , Poluentes do Solo , Solo , Carvão Vegetal/química , Poluentes do Solo/química , Metais Pesados/química , Solo/química , Peso Molecular , Concentração de Íons de Hidrogênio , Cádmio/química , Tartaratos/química , Malatos/química , Ácido Cítrico/química , Recuperação e Remediação Ambiental/métodos , Ácido Oxálico/química , Adsorção , Oryza/química
2.
J Biol Chem ; 300(6): 107394, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38768813

RESUMO

Periprosthetic osteolysis and subsequent aseptic loosening are the primary causes of failure following total joint arthroplasty. Wear particle-induced osteogenic impairment is recognized as an important contributing factor in the development of osteolysis, with endoplasmic reticulum (ER) stress emerging as a pivotal underlying mechanism. Hence, searching for potential therapeutic targets and agents capable of modulating ER stress in osteoblasts is crucial for preventing aseptic loosening. Kaempferol (KAE), a natural flavonol compound, has shown promising osteoprotective effects and anti-ER stress properties in diverse diseases. However, the influence of KAE on ER stress-mediated osteogenic impairment induced by wear particles remains unclear. In this study, we observed that KAE effectively relieved TiAl6V4 particles-induced osteolysis by improving osteogenesis in a mouse calvarial model. Furthermore, we demonstrated that KAE could attenuate ER stress-mediated apoptosis in osteoblasts exposed to TiAl6V4 particles, both in vitro and in vivo. Mechanistically, our results revealed that KAE mitigated ER stress-mediated apoptosis by upregulating the IRE1α-XBP1s pathway while concurrently partially inhibiting the IRE1α-regulated RIDD and JNK activation. Collectively, our findings suggest that KAE is a prospective therapeutic agent for treating wear particle-induced osteolysis and highlight the IRE1α-XBP1s pathway as a potential therapeutic target for preventing aseptic loosening.


Assuntos
Estresse do Retículo Endoplasmático , Endorribonucleases , Quempferóis , Osteoblastos , Osteogênese , Osteólise , Proteínas Serina-Treonina Quinases , Proteína 1 de Ligação a X-Box , Animais , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Quempferóis/farmacologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteína 1 de Ligação a X-Box/metabolismo , Proteína 1 de Ligação a X-Box/genética , Camundongos , Osteogênese/efeitos dos fármacos , Endorribonucleases/metabolismo , Endorribonucleases/genética , Osteoblastos/metabolismo , Osteoblastos/efeitos dos fármacos , Osteólise/metabolismo , Osteólise/induzido quimicamente , Osteólise/patologia , Osteólise/tratamento farmacológico , Apoptose/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Masculino , Humanos , Camundongos Endogâmicos C57BL
3.
Artigo em Inglês | MEDLINE | ID: mdl-38578884

RESUMO

Myocardial infarction refers to the ischemic necrosis of myocardium, characterized by a sharp reduction or interruption of blood flow in the coronary arteries due to the coronary artery occlusion, resulting in severe and prolonged ischemia in the corresponding myocardium and ultimately leading to ischemic necrosis of the myocardium. Given its high risk, it is considered as one of the most serious health threats today. In current clinical practice, multiple approaches have been explored to diminish myocardial oxygen consumption and alleviate symptoms, but notable success remains elusive. Accumulated clinical evidence has showed that the implantation of mesenchymal stem cell for treating myocardial infarction is both effective and safe. Nevertheless, there persists controversy and variability regarding the standardizing MSC transplantation protocols, optimizing dosage, and determining the most effective routes of administration. Addressing these remaining issues will pave the way of integration of MSCs as a feasible mainstream cardiac treatment.

4.
ACS Appl Mater Interfaces ; 16(13): 17041-17050, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38517684

RESUMO

The ultrafast manipulation of spin in ferromagnet-semiconductor (FM/SC) heterojunctions is a key issue for advancing spintronics, where magnetic damping and interfacial spin transport often define device efficiency. Leveraging selective optical excitation in semiconductors offers a unique approach to spin manipulation in FM/SC heterojunctions. Herein, we investigated the magnetic dynamics of a Co2FeAl/n-GaAs heterojunction using the time-resolved magneto-optical Kerr technique and observed the considerably enhanced magnetic damping of Co2FeAl when GaAs is photoexcited near its band edge. This enhancement is attributed to an enhanced spin-pumping effect facilitated by spin-dependent carrier tunneling and capture within the Co2FeAl layer. Moreover, circularly polarized light excites spin-polarized band-edge photocarriers, further impacting the magnetic damping of Co2FeAl through an additional optical spin-transfer torque on the magnetic moment of Co2FeAl. Our results provide a valuable reference for manipulating spin-pumping and interfacial spin transport in FM/SC heterojunctions, showcasing the advantage of optical control of semiconductor photocarriers for the ultrafast manipulation of magnetic dynamics and interfacial spin transfer.

6.
Science ; 382(6677): 1379-1383, 2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38127754

RESUMO

Aerogels have been considered as an ideal material for thermal insulation. Unfortunately, their application in textiles is greatly limited by their fragility and poor processability. We overcame these issues by encapsulating the aerogel fiber with a stretchable layer, mimicking the core-shell structure of polar bear hair. Despite its high internal porosity over 90%, our fiber is stretchable up to 1000% strain, which is greatly improved compared with that of traditional aerogel fibers (~2% strain). In addition to its washability and dyeability, our fiber is mechanically robust, retaining its stable thermal insulation property after 10,000 stretching cycles (100% strain). A sweater knitted with our fiber was only one-fifth as thick as down, with similar performance. Our strategy for this fiber provides rich possibilities for developing multifunctional aerogel fibers and textiles.

7.
RSC Adv ; 13(47): 33446-33452, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-38025873

RESUMO

In modern society, people spend most of their time indoors engaging in their work and home life. However, indoor air pollution is a potential risk to health, and it is associated with many diseases. Wooden furniture, as the most popular indoor furniture used in modern times, is a major source of indoor air pollution, so it has become imperative to explore the composition and release kinetics characteristics of toxic and hazardous substances from wood-based panels. In this study, thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was used to detect the release of organic compounds from wood panels, and determine the release kinetics of the organic compounds dimethyl acetal, phenol, toluene and decanoic acid via bi-exponential and mass transfer models to provide a theoretical basis for targeted pollution prevention and control. In this project, a climate chamber method was used to conduct a 120 h continuous sampling of the release concentration of compounds from wood panels. The TD-GC-MS method was used to analyze the sampling tubes, and the concentration-time data were fitted to the bi-exponential and mass transfer models. The emission factor equation was obtained from the bi-exponential model. The critical physical parameters, such as the initial internal release concentration C0, internal diffusion rate Dm, and solid-phase/gas-phase partition coefficient K, were obtained from the mass transfer model. Finally, it was found that dimethyl acetal and toluene were easily and rapidly released into the air, while phenol and decanoic acid were slowly released into the ambient air. The two sets of release kinetics characteristics provide an essential theoretical basis for targeted pollution prevention and control, as well as a methodological path for studying the release kinetics of different toxic and hazardous substances.

8.
Polymers (Basel) ; 15(4)2023 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-36850327

RESUMO

This study investigated the impact of surface basicity on the performance of layered double hydroxides (LDHs) as heat stabilizers for polyvinyl chloride (PVC). LDHs with varying surface basicity were synthesized and characterized using XRD, SEM, BET, and CO2-TPD. The LDHs were then combined with zinc stearate and dibenzoylmethane to create an environmentally friendly heat stabilizer and added to PVC. The resulting PVC composites were evaluated for thermal stability using the oven-aging method. The results showed that a lower Mg/Al molar ratio (2.0) improved the initial whiteness and long-term thermal stability of PVC composites compared to higher ratios (2.5, 3.0, and 3.5). Replacing Mg with Zn in the LDHs had a similar effect to that of reducing the Mg/Al ratio. Crosslinking the laminae of LDHs with 5% silane coupling agent KH-560 reduced the surface basicity of LDHs by 79%, increasing the chromaticity index, b*, and thermal stability time of PVC composites by 48% and 14%, respectively. A descriptive relationship was established between the structure and surface basicity of LDHs and the initial whiteness and long-term thermal stability of PVC composites.

9.
Ren Fail ; 45(1): 2120821, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36648018

RESUMO

Artemisinin has immunomodulatory, anti-inflammatory, and antifibrotic effects. Some studies have demonstrated that artemisinins have a protective effect on the kidney. DHA is a derivative of artemisinin and has effects similar to those of artemisinin. Human bone marrow-derived mesenchymal stem cells (BMSCs) accelerate renal repair following acute injury. In the study, we investigated the effects of combination therapy with DHA and BMSCs on membranous nephropathy (MN) mice. The 24-h urinary protein, serum total cholesterol (TC) and triglyceride (TG) levels, and renal histopathology, were measured to evaluate kidney damage. Anti-PLA2R, IgG, and complement 3 (C3) were detected by ELISA. The expression levels of the podocyte injury-related proteins were analyzed by immunohistochemistry. The protein expression levels of α-SMA, ED-1, TGF-ß1, p-Smad2, and p-Smad3 were detected by western blot to analyze renal fibrosis and its regulatory mechanism. Results showed that combination therapy with DHA and BMSCs significantly ameliorated kidney damage in MN model mice by decreasing the levels of 24 h urinary protein, TC and TG. This combination therapy also improved renal histology and reduced the expression of IgG and C3 in the glomerulus. In addition, this combination therapy decreased the expression of podocin and nephrin and relieved renal fibrosis by downregulating α-SMA and ED-1. Furthermore, this combination therapy suppressed TGF-ß1 expression and Smad2/3 phosphorylation. This result (i.e., this combination therapy inhibited the TGF-ß1/Smad pathway) was also supported in vitro. Taken together, combination therapy with DHA and BMSCs ameliorated podocyte injury and renal fibrosis in MN mice by downregulating the TGFß1/Smad pathway.


Assuntos
Glomerulonefrite Membranosa , Nefropatias , Podócitos , Camundongos , Humanos , Animais , Fator de Crescimento Transformador beta1/metabolismo , Podócitos/metabolismo , Nefropatias/metabolismo , Fibrose , Imunoglobulina G/metabolismo , Proteínas Smad
10.
Environ Res ; 220: 115120, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36563980

RESUMO

Soil washing is an efficient, economical, and green remediation technology for removing several heavy metal (loid)s from contaminated industrial sites. The extraction of green and efficient washing agents from low-cost feedback is crucially important. In this study, a soluble humic substance (HS) extracted from leonardite was first tested to wash soils (red soil, fluvo-aquic soil, and black soil) heavily contaminated with arsenic (As) and cadmium (Cd). A D-optimal mixture design was investigated to optimize the washing parameters. The optimum removal efficiencies of As and Cd by single HS washing were found to be 52.58%-60.20% and 58.52%-86.69%, respectively. Furthermore, a two-step sequential washing with chemical reductant NH2OH•HCl coupled with HS (NH2OH•HCl + HS) was performed to improve the removal efficiency of As and Cd. The two-step sequential washing significantly enhanced the removal of As and Cd to 75.25%-81.53% and 64.53%-97.64%, which makes the residual As and Cd in soil below the risk control standards for construction land. The two-step sequential washing also effectively controlled the mobility and bioavailability of residual As and Cd. However, the activities of soil catalase and urease significantly decreased after the NH2OH•HCl + HS washing. Follow-up measures such as soil neutralization could be applied to relieve and restore the soil enzyme activity. In general, the two-step sequential soil washing with NH2OH•HCl + HS is a fast and efficient method for simultaneously removing high content of As and Cd from contaminated soils.


Assuntos
Arsênio , Recuperação e Remediação Ambiental , Metais Pesados , Poluentes do Solo , Substâncias Húmicas/análise , Cádmio/análise , Arsênio/química , Substâncias Redutoras , Metais Pesados/análise , Solo/química , Poluentes do Solo/análise
11.
Nanoscale ; 14(47): 17571-17580, 2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36408600

RESUMO

Black silicon electrodes with inverted pyramid arrays (SiIPs) are promising for efficient photoelectrochemical water splitting due to their excellent photoelectric properties and quasi-hydrophilicity. In this work, an elaborate study on microstructure regulation of SiIP photocathodes is reported. We find that on SiIPs where sidewalls have been processed with copper-assisted chemical etching (Cu-ACE), there are vast numbers of micro-pits distributed (deep holes and shallow grooves) that exactly determine electrode performance, which is a result of homogeneous Cu2+ oxidation of Si. Furthermore, SiIP microstructural features can be effectively adjusted via controlling the etchant composition and introducing alkali post-treatment. Taking the trade-off between light trapping ability and charge separation capacity into consideration, we optimized the hydrogen evolution reaction (HER) activity of a SiIP photocathode, and its onset potential was decreased to -0.35 V vs. RHE. On this basis, we constructed reliable heterojunctions to further improve the sluggish HER kinetics. The optimized SiIPs/TiO2/MoSx cathode exhibits a considerable photocurrent density of 9.45 mA cm-2 at zero HER overpotential for 18 h in acidic media. Notably, our work presents a detailed physical insight into micro-pit formation and elimination in Cu-ACE, and describes the dependency of SiIP-based electrode performance on the microstructure morphology, paving a new way for its potential application in unbiased overall water splitting.

12.
PeerJ ; 10: e14162, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36225909

RESUMO

Humic acids (HAs) are complex organic substances with abundant functional groups (e.g., carboxyl, phenolic-OH, etc.). They are commonly distributed in the soil environment and exert a double-edged sword effect in controlling the migration and transformation of uranium. However, the effects of HAs on dynamic processes associated with uranium transformation are still unclear. In this study, we used HAs derived from leonardite (L-HA) and commercial HA (C-HA) as exogenous organic matter and C-HA as the reference. UO2, UO3, and UO2(NO3)2 were used as the sources of U to explore the fractionations of uranium in the soil. We also studied the behavior of the HA. The incubation experiments were designed to investigate the effects of HA on the soil pH, uranium fraction transformation, dynamic behavior of exchangeable, weak acid, and labile uranium. The observations were made for one month. The results showed that soil pH decreased for L-HA but increased for C-HA. Under these conditions, uranium tended to transform into an inactive fraction. The dynamic behavior of exchangeable, weak acid, and labile uranium varied with the sources of HA and uranium. This study highlighted that HA could affect soil pH and the dynamic redistribution of U fractions. The results suggest that the sources of HA and U should be considered when using HA as the remediation material for uranium-contaminated soils.


Assuntos
Substâncias Húmicas , Urânio , Substâncias Húmicas/análise , Solo/química , Urânio/análise , Minerais/química
13.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 34(5): 454-458, 2022 May.
Artigo em Chinês | MEDLINE | ID: mdl-35728843

RESUMO

OBJECTIVE: To analyze the rules of medication and principles of formulas for the treatment of coronavirus disease 2019 (COVID-19) using the traditional Chinese medicine inheritance support platform (V2.5). METHODS: The clinical data, including gender, age, clinical symptoms, frequency of traditional Chinese medicine medication and prescription information, of patients with COVID-19 and asymptomatic infection who were admitted to Hebei COVID-19 designated hospital supported by medical team of First Affiliated Hospital of Hebei University of Chinese Medicine from January to March 2021 were collected. The information data were input into the traditional Chinese medicine inheritance support platform (V2.5). The data mining and analysis were realized by the integrated association rules and complex entropy clustering analysis methods of the software, including the analysis of the frequency of each drug use, drug meridian, taste, and prescription rules, and the new prescriptions were developed. RESULTS: A total of 564 patients (564 prescriptions) were enrolled, involving 200 Chinese herbs, including 357 cases of common COVID-19 and 207 cases of asymptomatic infection. The proportion of women with common COVID-19 was high, and the high incidence age group was 51-70 years old. There was no significant difference in gender of asymptomatic infection, and the high incidence age group was 1-20 years old. The main clinical manifestations of most patients were head heavy and cough, followed by low fever and cough with sputum, the main tongue coating and pulse pattern were similar in both types of patients. The frequency of traditional Chinese medicine used in patients with common type of COVID-19 from high to low was liquorice root (326 times), indian bread (264 times), pinellia tuber (263 times), bitter apricot seed (236 times), baical skullcap root (229 times), gypsum (205 times), agastache rugosus (201 times), dried tangerine peel (194 times), ephedra (184 times), and Chinese thorowax root (163 times), while that used by asymptomatic infection were baical skullcap root (174 times), liquorice root (142 times), medicated leaven (137 times), agastache rugosus (127 times), pinellia tuber (114 times), Chinese thorowax root (100 times), officinal magnolia bark (91 times), atractylodes rhizome (89 times), peony root (84 times), and milkvetch root (83 times). The two types of patients were mainly treated with warm, cold and flat drugs, and the nature and taste were mainly pungent, bitter and sweet. The meridian tropism of drugs was mainly lung, spleen and stomach. High frequency drug formulation mainly included drugs for resolving turbidity and detoxification. At the same time, seven new prescriptions for common COVID-19 and four new prescriptions for asymptomatic infection were developed. CONCLUSIONS: The primary reason for the COVID-19 occurrence and development is turbidity-toxin and the qi of plague, and resolving turbidity and detoxication are the basic treating principle. On the basis, for patients with common COVID-19, symptomatic treatment such as relieving exterior syndrome, clearing heat, resolving phlegm, and antitussive drugs should be taken into account at the same time, while the treatment of asymptomatic infections should focus more on supporting the body and eliminating the harmful pathogens.


Assuntos
Tratamento Farmacológico da COVID-19 , Medicamentos de Ervas Chinesas , Adolescente , Adulto , Idoso , Infecções Assintomáticas , Criança , Pré-Escolar , Tosse/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Feminino , Humanos , Lactente , Medicina Tradicional Chinesa , Pessoa de Meia-Idade , Prescrições , Adulto Jovem
14.
Front Bioeng Biotechnol ; 10: 850303, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35528209

RESUMO

As hematopoietic stem cells can differentiate into all hematopoietic lineages, mitigating the damage to hematopoietic stem cells is important for recovery from overdose radiation injury. Cells in bone marrow microenvironment are essential for hematopoietic stem cells maintenance and protection, and many of the paracrine mediators have been discovered in shaping hematopoietic function. Several recent reports support exosomes as effective regulators of hematopoietic stem cells, but the role of osteoblast derived exosomes in hematopoietic stem cells protection is less understood. Here, we investigated that osteoblast derived exosomes could alleviate radiation damage to hematopoietic stem cells. We show that intravenous injection of osteoblast derived exosomes promoted WBC, lymphocyte, monocyte and hematopoietic stem cells recovery after irradiation significantly. By sequencing osteoblast derived exosomes derived miRNAs and verified in vitro, we identified miR-21 is involved in hematopoietic stem cells protection via targeting PDCD4. Collectively, our data demonstrate that osteoblast derived exosomes derived miR-21 is a resultful regulator to radio-protection of hematopoietic stem cells and provide a new strategy for reducing radiation induced hematopoietic injury.

15.
Environ Sci Pollut Res Int ; 29(39): 59043-59051, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35381922

RESUMO

As a commonly used amendment to soil contaminated by heavy metals, biochar has attracted great attention and has been applied for decades due to the benefits to the soil. However, the effects of biochar on the dynamic behavior of soil properties and metal fractions are still unclear. Here, we used two biochars, derived from biowastes (reed and bamboo willow), to treat two cadmium (Cd)-contaminated soils, S1 (loamy sand) and S2 (sandy loam), and determined the dynamic effects. The incubation experiments were designed to investigate the effects of biochar on the dynamic behavior of soil pH, dissolved organic matter (DOM), bioavailable Cd, and the transformation of Cd fractions for 270 days. The results showed that the soil pH, DOM, and bioavailable Cd initially increased and then decreased with incubation time, and the soil pH and DOM were higher, but bioavailable Cd content was lower than the original value. The transformation of the metal fractions changed dynamically, and the exchangeable fraction of Cd decreased with incubation time. Furthermore, the correlation results showed that the DOM can directly control the redistribution of Cd fractions, while soil pH can control it indirectly by regulating the DOM. This study highlighted that biochar can affect soil pH and DOM, redistribute Cd fractions, decrease bioavailable Cd content, and lower the potential risk of heavy metals. This study suggests ways to immobilize heavy metals in contaminated soils using biochar.


Assuntos
Metais Pesados , Poluentes do Solo , Cádmio/análise , Carvão Vegetal/química , Metais Pesados/análise , Solo/química , Poluentes do Solo/análise
16.
Bone Res ; 10(1): 18, 2022 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-35210394

RESUMO

Mechanical stimulation plays an important role in bone remodeling. Exercise-induced mechanical loading enhances bone strength, whereas mechanical unloading leads to bone loss. Increasing evidence has demonstrated that long noncoding RNAs (lncRNAs) play key roles in diverse biological, physiological and pathological contexts. However, the roles of lncRNAs in mechanotransduction and their relationships with bone formation remain unknown. In this study, we screened mechanosensing lncRNAs in osteoblasts and identified Neat1, the most clearly decreased lncRNA under simulated microgravity. Of note, not only Neat1 expression but also the specific paraspeckle structure formed by Neat1 was sensitive to different mechanical stimulations, which were closely associated with osteoblast function. Paraspeckles exhibited small punctate aggregates under simulated microgravity and elongated prolate or larger irregular structures under mechanical loading. Neat1 knockout mice displayed disrupted bone formation, impaired bone structure and strength, and reduced bone mass. Neat1 deficiency in osteoblasts reduced the response of osteoblasts to mechanical stimulation. In vivo, Neat1 knockout in mice weakened the bone phenotypes in response to mechanical loading and hindlimb unloading stimulation. Mechanistically, paraspeckles promoted nuclear retention of E3 ubiquitin ligase Smurf1 mRNA and downregulation of their translation, thus inhibiting ubiquitination-mediated degradation of the osteoblast master transcription factor Runx2, a Smurf1 target. Our study revealed that Neat1 plays an essential role in osteoblast function under mechanical stimulation, which provides a paradigm for the function of the lncRNA-assembled structure in response to mechanical stimulation and offers a therapeutic strategy for long-term spaceflight- or bedrest-induced bone loss and age-related osteoporosis.

17.
Nanomaterials (Basel) ; 11(12)2021 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-34947528

RESUMO

Realizing the anisotropic deep trenching of GaN without surface damage is essential for the fabrication of GaN-based devices. However, traditional dry etching technologies introduce irreversible damage to GaN and degrade the performance of the device. In this paper, we demonstrate a damage-free, rapid metal-assisted chemical etching (MacEtch) method and perform an anisotropic, deep trenching of a GaN array. Regular GaN microarrays are fabricated based on the proposed method, in which CuSO4 and HF are adopted as etchants while ultraviolet light and Ni/Ag mask are applied to catalyze the etching process of GaN, reaching an etching rate of 100 nm/min. We comprehensively explore the etching mechanism by adopting three different patterns, comparing a Ni/Ag mask with a SiN mask, and adjusting the etchant proportion. Under the catalytic role of Ni/Ag, the GaN etching rate nearby the metal mask is much faster than that of other parts, which contributes to the formation of deep trenches. Furthermore, an optimized etchant is studied to restrain the disorder accumulation of excessive Cu particles and guarantee a continuous etching result. Notably, our work presents a novel low-cost MacEtch method to achieve GaN deep etching at room temperature, which may promote the evolution of GaN-based device fabrication.

18.
Zhongguo Zhen Jiu ; 41(11): 1216-20, 2021 Nov 12.
Artigo em Chinês | MEDLINE | ID: mdl-34762373

RESUMO

OBJECTIVE: To compare the effect of moxibustion combined with basic treatment and simple basic treatment on the clinical symptoms, renal function and hypercoagulable state in patients with idiopathic membranous nephropathy (IMN) of low to medium risk with spleen-kidney deficiency and blood stasis. METHODS: A total of 60 patients with IMN of low to medium risk with spleen-kidney deficiency and blood stasis were randomized into an observation group (30 cases, 2 cases dropped off) and a control group (30 cases, 1 case dropped off). In the control group, the conventional basic treatment of anti-hypertension, regulating blood lipid and anti-coagulation was adopted. On the basis of the control group, moxibustion was applied at Shenshu (BL 23), Pishu (BL 20), Guanyuan (CV 4), Zusanli (ST 36) and Sanyinjiao (SP 6) in the observation group, once a day, 5 days a week continuously with 2 day interval. The treatment of 6 months was required in the both groups. Before treatment and 3 and 6 months into treatment, the total TCM syndrome score, the renal function indexes (24-hour urinary protein quantity [UTP], albumin [ALB], urea nitrogen [BUN] and creatinine [Scr]), the blood coagulation indexes (fibrinogen [FIB], D-Dimer [D-D], p-selection and von Willebrand factor [vWF]), total cholesterol (TC) and triacylglycerol (TG) levels were observed, and the therapeutic efficacy was evaluated on 3 and 6 months into treatment in the two groups. RESULTS: The effective rates of 3 and 6 months into treatment were 78.6% (22/28) and 89.3% (25/28) in the observation group, which were higher than 62.1% (18/29) and 75.9% (22/29) in the control group respectively (P<0.05). On 3 and 6 months into treatment, the total TCM syndrome scores were decreased compared before treatment in the both groups (P<0.05), and those in the observation group were lower than the control group (P<0.05). On 3 months into treatment, the levels of UTP, FIB, D-D, P-selection and vWF were decreased (P<0.05), the level of ALB was increased (P<0.05) compared before treatment in the observation group; the levels of UTP and FIB were decreased compared before treatment in the control group (P<0.05); the level of ALB in the observation group was higher than that in the control group (P<0.05), the levels of FIB and vWF in the observation group were lower than those in the control group (P<0.05). On 6 months into treatment, the levels of UTP, FIB, D-D, P-selection, vWF, TC and TG were decreased (P<0.05), the levels of ALB were increased (P<0.05) compared before treatment in the both groups (P<0.05); the levels of UTP, FIB, D-D, P-selection, vWF, TC and TG in the observation group were lower than those in the control group, the level of ALB in the observation group was higher than that in the control group (P<0.05). CONCLUSION: Moxibustion combined with basic treatment can effectively improve the clinical symptoms, renal function and renal microcirculation in patients with idiopathic membranous nephropathy of low to medium risk with spleen-kidney deficiency and blood stasis, the therapeutic effect is superior to the simple basic treatment.


Assuntos
Terapia por Acupuntura , Glomerulonefrite Membranosa , Moxibustão , Pontos de Acupuntura , Humanos , Rim/fisiologia , Baço
19.
Research (Wash D C) ; 2021: 9756945, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34368766

RESUMO

Human metallothionein (MT) is a small-size yet efficient metal-binding protein, playing an essential role in metal homeostasis and heavy metal detoxification. MT contains two domains, each forming a polynuclear metal cluster with an exquisite hexatomic ring structure. The apoprotein is intrinsically disordered, which may strongly influence the clusters and the metal-thiolate (M-S) bonds, leading to a highly dynamic structure. However, these features are challenging to identify due to the transient nature of these species. The individual signal from dynamic conformations with different states of the cluster and M-S bond will be averaged and blurred in classic ensemble measurement. To circumvent these problems, we combined a single-molecule approach and multiscale molecular simulations to investigate the rupture mechanism and chemical stability of the metal cluster by a single MT molecule, focusing on the Zn4S11 cluster in the α domain upon unfolding. Unusual multiple unfolding pathways and intermediates are observed for both domains, corresponding to different combinations of M-S bond rupture. None of the pathways is clearly preferred suggesting that unfolding proceeds from the distribution of protein conformational substates with similar M-S bond strengths. Simulations indicate that the metal cluster may rearrange, forming and breaking metal-thiolate bonds even when MT is folded independently of large protein backbone reconfiguration. Thus, a highly dynamic polynuclear metal cluster with multiple conformational states is revealed in MT, responsible for the binding promiscuity and diverse cellular functions of this metal-carrier protein.

20.
Sci Adv ; 7(31)2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34330700

RESUMO

Van der Waals epitaxy provides a fertile playground for the monolithic integration of various materials for advanced electronics and optoelectronics. Here, a previously unidentified nanorod-assisted van der Waals epitaxy is developed and nearly single-crystalline GaN films are first grown on amorphous silica glass substrates using a graphene interfacial layer. The epitaxial GaN-based light-emitting diode structures, with a record internal quantum efficiency, can be readily lifted off, becoming large-size flexible devices. Without the effects of the potential field from a single-crystalline substrate, we expect this approach to be equally applicable for high-quality growth of nitrides on arbitrary substrates. Our work provides a revolutionary technology for the growth of high-quality semiconductors, thus enabling the hetero-integration of highly mismatched material systems.

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