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Using functionalized supporting materials for the immobilization of molecular catalysts is an appealing strategy to improve the efficiency of molecular electrocatalysis. Herein, we report the covalent tethering of cobalt porphyrins on phenolic resins (PR) for improved electrocatalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). A cobalt porphyrin bearing an alkyl bromide substituent was covalently tethered on phenolic resins, through the substitution reaction of alkyl bromides with phenolic hydroxyl groups, to afford molecule-engineered phenolic resins (Co-PR). The resulted Co-PR was efficient for electrocatalytic ORR and OER by displaying an ORR half-wave potential of E1/2=0.78â V versus RHE and an OER overpotential of 420â mV to get 10â mA/cm2 current density. We propose that the many residual phenolic hydroxyl groups on PR will surround the tethered Co porphyrin and play critical roles in facilitating proton and electron transfers. Importantly, Co-PR outperformed unmodified PR and PR loaded with Co porphyrins through simple physical adsorption (termed Co@PR). The zinc-air battery assembled using Co-PR displayed a performance comparable to that using Pt/C+Ir/C. This work is significant to present phenolic resins as a functionalized material to support molecular electrocatalysts and demonstrate the strategy to improve molecular electrocatalysis with the use of phenolic resin residues.
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The front cover artwork is provided by Rui Cao's group at Shaanxi Normal University. The image shows the design of Co-porphyrin-engineered phenolic resins with intramolecular phenolic hydroxyl groups to facilitate proton and electron transfers for efficient oxygen electrocatalysis, which is bioinspired by cytochrome c oxidases, and shows the excellent performance of Zn-air batteries assembled with the hybrid material. Read the full text of the Research Article at 10.1002/cphc.202400017.
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Ultraviolet (UV) radiation has been widely utilized as a disinfection strategy to effectively eliminate various pathogens. The disinfection task achieves complete coverage of object surfaces by planning the motion trajectory of autonomous mobile robots and the UVC irradiation strategy. This introduces an additional layer of complexity to path planning, as every point on the surface of the object must receive a certain dose of irradiation. Nevertheless, the considerable dosage required for virus inactivation often leads to substantial energy consumption and dose redundancy in disinfection tasks, presenting challenges for the implementation of robots in large-scale environments. Optimizing energy consumption of light sources has become a primary concern in disinfection planning, particularly in large-scale settings. Addressing the inefficiencies associated with dosage redundancy, this study proposes a dose coverage planning framework, utilizing MOPSO to solve the multi-objective optimization model for planning UVC dose coverage. Diverging from conventional path planning methodologies, our approach prioritizes the intrinsic characteristics of dose accumulation, integrating a UVC light efficiency factor to mitigate dose redundancy with the aim of reducing energy expenditure and enhancing the efficiency of robotic disinfection. Empirical trials conducted with autonomous disinfecting robots in real-world settings have corroborated the efficacy of this model in deactivating viruses.
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Oncogene activation, massive proliferation, and increased nutrient demands often result in nutrient and oxygen deprivation in solid tumors including breast cancer (BC), leading to the induction of oxidative stress and endoplasmic reticulum (ER) stress, and subsequently triggering integrated stress response (ISR). To elucidate the role of long non-coding RNAs (lncRNAs) in the ISR of BC, we performed transcriptome analyses and identified a lncRNA, UBA6-AS1, which was upregulated upon amino acid deprivation and ER stress. UBA6-AS1 was preferentially induced in triple-negative BC (TNBC) cells deprived of arginine or glutamine, two critical amino acids required for cancer cell growth, or treated with ER stress inducers. Mechanistically, UBA6-AS1 was regulated through the GCN2/eIF2α/ATF4 pathway, one of the major routes mediating ISR in amino acid sensing. In addition, both in vitro and in vivo assays indicated that UBA6-AS1 promoted TNBC cell survival when cells encountered metabolic stress, implicating a regulatory role of UBA6-AS1 in response to intratumoral metabolic stress during tumor progression. Moreover, PARP1 expression and activity were positively regulated by the GCN2/UBA6-AS1 axis upon amino acid deprivation. In conclusion, our data suggest that UBA6-AS1 is a novel lncRNA regulating ISR upon metabolic stress induction to promote TNBC cell survival. Furthermore, the GCN2-ATF4 axis is important for UBA6-AS1 induction to enhance PARP1 activity and could serve as a marker for the susceptibility of PARP inhibitors in TNBC.
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Aminoácidos/deficiência , Estresse do Retículo Endoplasmático , Proteínas Serina-Treonina Quinases/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Fator 4 Ativador da Transcrição/genética , Fator 4 Ativador da Transcrição/metabolismo , Aminoácidos/metabolismo , Animais , Feminino , Células HEK293 , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas Serina-Treonina Quinases/genética , RNA Antissenso , Neoplasias de Mama Triplo Negativas/genéticaRESUMO
Kinkéliba (Combretum micranthum, Seh-Haw in Wolof) is a popular bush tea in West African countries. Although the kinkéliba plant's leaves have been widely consumed for its nutritional and medicinal properties, its benefits on skin health potential have been practically untouched. In human epidermal primary keratinocytes, vitexin and isovitexin-rich kinkéliba extract treatment significantly (p < 0.001) enhanced up to 39.6% of the cell survival rate decreased by UV radiation irritation. The treatment of kinkéliba leaf extracts also reduced the production of UV-induced pro-inflammatory cytokines IL-6 and IL-8 by 57.6% and 42.5%, respectively (p < 0.001), which cause skin redness and skin barrier dysfunction, as well as wrinkles and collagen degradation. The anti-inflammation efficacy of kinkéliba leaf extracts might involve significant inhibition on the levels of cellular reactive oxygen species (ROS) (-70.8%, p < 0.001) and nitrotyrosine (-56.9%, p < 0.05). Further topical applications of kinkéliba leaf extract gel were found to reduce sodium lauryl sulfate (SLS)-induced skin inflammation: at D7, the skin trans-epidermal water loss (TEWL) and skin redness (a* value) were both reduced by 59.81% (p < 0.001) and 22.4% (p < 0.001), compared with D0. In vitro and in vivo data support a new topical application of the kinkéliba leaf as an effective active ingredient for the treatment of skin inflammation, as well as subsequent barrier dysfunction and inflammaging.
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Combretum , Dermatite , Humanos , Extratos Vegetais/farmacologia , Pele , QueratinócitosRESUMO
The tendency of global urban expansion to be slope climbing has partly become possible with scarce cropland resources in plains. However, the scientific understanding of the quantity, intensity, pattern, and effect of the slope climbing of urban expansion (SCE) is minimal globally. In this study, we have attempted to quantify and evaluate global SCE from Suomi National Polar-orbiting Partnership (SNPP)-Visible Infrared Imaging Radiometer Suite (VIIRS)-like data and other auxiliary data. Results revealed that global SCE areas unevenly increased from 22,760 km2 to 90,720 km2 from 2000 to 2020, with an annual growth rate of 21.72%, in which low-environment cost type areas increased from 21,550 km2 to 84,010 km2 while high-environment cost type (HEC) areas increased from 1210 km2 to 6710 km2. One remarkable phenomenon is that China's SCE areas in 2020 were more than 11 times those in 2000. In addition, global SCE intensity increased by about 3.4-fold from 2000 to 2020 and the rapid growth of HEC intensity is concentrated in Asia and North America. SCE is mostly affected by urban population growth and terrain. Economic development also promotes its development to a certain extent. We also noted that global SCE potentially made a considerable contribution to saved cropland, saving about 46,747 km2 with a theoretical increased grain yield of 25,020 × 103 t. Our study provides timely and transparent monitoring of global SCE and offers new insights into sustainable urban development.
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Crescimento Demográfico , Urbanização , Ásia , Segurança Alimentar , América do Norte , ChinaRESUMO
Rice (Oryza sativa L.) has two ecotypes, upland and lowland rice, that have been observed to show different tolerance levels under flooding stress. In this study, two rice cultivars, upland (Up221, flooding-intolerant) and lowland (Low88, flooding-tolerant), were initially used to study their molecular mechanisms in response to flooding germination. We observed that variations in the OsCBL10 promoter sequences in these two cultivars might contribute to this divergence in flooding tolerance. Further analysis using another eight rice cultivars revealed that the OsCBL10 promoter could be classified as either a flooding-tolerant type (T-type) or a flooding-intolerant type (I-type). The OsCBL10 T-type promoter only existed in japonica lowland cultivars, whereas the OsCBL10 I-type promoter existed in japonica upland, indica upland and indica lowland cultivars. Flooding-tolerant rice cultivars containing the OsCBL10 T-type promoter have shown lower Ca2+ flow and higher α-amylase activities in comparison to those in flooding-intolerant cultivars. Furthermore, the OsCBL10 overexpression lines were sensitive to both flooding and hypoxic treatments during rice germination with enhanced Ca2+ flow in comparison to wild-type. Subsequent findings also indicate that OsCBL10 may affect OsCIPK15 protein abundance and its downstream pathways. In summary, our results suggest that the adaptation to flooding stress during rice germination is associated with two different OsCBL10 promoters, which in turn affect OsCBL10 expression in different cultivars and negatively affect OsCIPK15 protein accumulation and its downstream cascade.
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Adaptação Fisiológica , Calcineurina/metabolismo , Cálcio/metabolismo , Oryza/genética , Regiões Promotoras Genéticas/genética , Calcineurina/genética , Ecótipo , Inundações , Variação Genética , Germinação , Oryza/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Sementes/genética , Sementes/fisiologia , Especificidade da Espécie , Estresse FisiológicoRESUMO
BACKGROUND: 3-monochloro-1, 2-propanediol fatty acid esters (3-MCPDEs) comprise a group of food toxicants formed during food processing. 3-MCPDEs have received increasing attention concerning their potential negative effects on human health. However, reports on the toxicity of 3-MCPD esters are still limited. To determine the effects of fatty acid substitutions on the toxicity of their esters, 1-stearic, 1-oleic, 1-linoleic, 1-linoleic-2-palmitic and 1-palmitic-2-linoleic acid esters of 3-MCPD were synthesized and evaluated with respect to their acute oral toxicities in Swiss mice. RESULTS: 3-MCPDEs were obtained through the reaction of 3-MCPD and fatty acid chlorides, and their purities and structures were characterized by ultraperformance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS), infrared, 1 H and 13 C spectroscopic analyses. Medial lethal doses of 1-stearic, 1-oleic, 1-linoleic, 1-linoleic-2-palmitic and 1-palmitic-2-linoleic acid esters were 2973.8, 2081.4, 2016.3, 5000 and > 5000 mg kg-1 body weight. For the first time, 3-MCPDEs were observed for their toxic effects in the thymus and lung. In addition, major histopathological changes, as well as blood urea nitrogen and creatinine, were examined for mice fed the five 3-MCPDEs. CONCLUSION: The results from the present study suggest that the degree of unsaturation, chain length, number of substitution and relative substitution locations of fatty acids might alter the toxicity of 3-MCPDEs. © 2016 Society of Chemical Industry.
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Diglicerídeos/toxicidade , Contaminação de Alimentos , Hidrocarbonetos Clorados/toxicidade , Fígado/efeitos dos fármacos , Monoglicerídeos/toxicidade , Síndromes Neurotóxicas/etiologia , Timo/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Diglicerídeos/síntese química , Diglicerídeos/química , Feminino , Manipulação de Alimentos , Hidrocarbonetos Clorados/síntese química , Hidrocarbonetos Clorados/química , Dose Letal Mediana , Fígado/patologia , Masculino , Camundongos , Estrutura Molecular , Monoglicerídeos/síntese química , Monoglicerídeos/química , Neurônios/efeitos dos fármacos , Neurônios/patologia , Síndromes Neurotóxicas/sangue , Síndromes Neurotóxicas/patologia , Tamanho do Órgão/efeitos dos fármacos , Distribuição Aleatória , Relação Estrutura-Atividade , Timo/patologia , Testes de Toxicidade AgudaRESUMO
The water-soluble cationic nickel(II) complex of meso-tetrakis(4-N-methylpyridyl)porphyrin (1) can electrocatalyze water oxidation to O2 in neutral aqueous solution (pH 7.0) with the onset of the catalytic wave appearing at â¼1.0 V (vs NHE). The homogeneous catalysis with 1 was verified. Catalyst 1 exhibited water oxidation activity in a pH range 2.0-8.0 and had a strict linear dependence of catalytic current on its concentration. After 10 h of constant potential electrolysis at 1.32 V (vs NHE), a negligible difference of the solution was observed by UV-vis. In addition, inspection of the working electrode by electrochemistry, scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDX) showed no sign of deposition of NiOx films. These results strongly argued that 1 is a real molecular electrocatalyst for water oxidation. The turnover frequency (TOF) for this process was 0.67 s(-1) at 20 °C. On the basis of results from the kinetic isotope effect (KIE) and inhibition experiments, electrochemical studies in various buffer solutions with different anions and pHs, and DFT calculations, a catalytic cycle of 1 for water oxidation via a formally Ni(IV) species was proposed.
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Water oxidation is the key step in natural and artificial photosynthesis for solar-energy conversion. As this process is thermodynamically unfavorable and is challenging from a kinetic point of view, the development of highly efficient catalysts with low energy cost is a subject of fundamental significance. Herein, we report on iron-based films as highly efficient water-oxidation catalysts. The films can be quickly deposited onto electrodes from Fe(II) ions in acetate buffer at pHâ 7.0 by simple cyclic voltammetry. The extremely low iron loading on the electrodes is critical for improved atom efficiency for catalysis. Our results showed that this film could catalyze water oxidation in neutral phosphate solution with a turnover frequency (TOF) of 756â h(-1) at an applied overpotential of 530â mV. The significance of this approach includes the use of earth-abundant iron, the fast and simple method for catalyst preparation, the low catalyst loading, and the large TOF for O2 evolution in neutral aqueous media.
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OBJECTIVE: The present study examined the relation between déjà vu experiences and paranormal beliefs in schizophrenic patients. METHODS: A total of 522 participants (54.5% female; mean age=33.3, SD=16.02) were recruited, including 422 healthy adults (60.9% female; mean age=29.48, SD=15.07) and 100 medicated adult schizophrenic patients (27.3% female; mean age=48.98, SD=8.57). The Chinese version of the Inventory of Déjà-vu Experiences Assessment was created via back translation. Chinese versions of the Revised Paranormal Belief Scale (CRPB), Beck Anxiety Inventory (CBAI), and Perceived Stress Scale (CPSS) were also used. RESULTS AND CONCLUSION: After controlling for age, gender, education, and anxiety, the results supported the following three hypotheses. Schizophrenic persons have fewer déjà vu experiences than normal persons. These experiences are positively related to paranormal beliefs in healthy adults but not in schizophrenic patients. Schizophrenic patients have higher scores than healthy adults on the psi and superstitious subscales of the CRPB.
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Antipsicóticos/uso terapêutico , Cultura , Déjà Vu , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Superstições , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Background: Starting from 2009, H1N1 has been one of the respiratory diseases that afflict the global population. Concurrently, due to the influence of COVID-19, it has become widely accepted that preventing the virus's spread necessitates personal protection measures and disinfection in public spaces. Experiments: This study conducted two experiments. In the classroom experiment, six UVC dose test points were calibrated to test whether the UVC dose at each testing point met the standards for inactivating IAVs and the time required to meet the standards. In the simulated classroom experiment, seven square slides made of IAVs were placed. After 10 min of robot movement, irradiated sterile square slides were made into suspension and injected into chicken embryos. Cultivate chicken embryos and conduct IAVs testing. Results: Classroom experiment has shown that 5 testing points can meet the standards for inactivating IAVs(3 mJ/cm2), with a required time of 80 min, 40 min, 15 min, 5 min and 10 min. The UVC dose for testing points that do not meet the standards in 80 min is only 0.5 mJ/cm2. The simulation classroom experiment outcomes revealed that 99.99 % of IAVs were deactivated. Furthermore, this study established both a desktop control group and a chair arm control group, both of which yielded identical results, indicating an inactivation logarithm of IAVs≥4log. Conclusion: The study presented that IAVs on the surface of an object can be effectively and rapidly deactivated at an irradiation density of 1.8 mW/cm2. Meanwhile, the study provides evidence of the feasibility of using the GXU robot to inactivate IAVs in a classroom environment.
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Tourism eco-efficiency is an important indicator to measure the sustainable development of tourism with the core objective of "minimum resource input and environmental damage, maximum economic and social output". This paper explores the spatial and temporal evolution characteristics of tourism eco-efficiency and its influencing factors in Fujian Province from 2011 to 2020 by combining the unexpected output Super-SBM model, gravity center model, standard deviation ellipse, and optimal parameters-based geographical detector model. The results are as follows. Tourism eco-efficiency in Fujian Province showed an overall fluctuating growth trend with an increase of 160.065% during the study period. The coefficient of variation of tourism eco-efficiency tends to fluctuate and decrease, and regional differences narrow. The spatial differentiation is remarkable, and it presents the spatial distribution characteristics of "Xiamen > Nanping > Quanzhou > Fuzhou > Longyan > Ningde > Sanming > Zhangzhou > Putian". The spatial pattern of tourism eco-efficiency is obvious in the direction of "northeast-southwest", and the trajectory of the center of gravity is "southwest-northeast-northwest", with spatial characteristics tending towards agglomeration. Tourism industry structure has the greatest impact on tourism eco-efficiency, followed by education level, urbanization level, technology innovation level, infrastructure investment, and economic development level. This study provides reference suggestions for improving tourism eco-efficiency which helps to promote adequate, balanced, and sustainable development of the regional tourism industry.
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The primary prerequisite for socioeconomic growth is good health, hence promoting residents' health is a vital objective of public policies. It is yet up for debate whether or not the digital economy (DE), which will be crucial to future economic growth, will eventually result in improvements in residents' health. Utilizing the China Family Panel Studies (CFPS) data in 2020, we explore how the DE affects residents' health. The findings reveal that residents' health is greatly enhanced by the DE. The eastern region sees a more dramatic improvement in residents' health as a result of the DE. Additionally, the DE can improve residents' health through the promotion of regional green development. The study's findings add to our knowledge of how the DE impacts residents' health while also offering recommendations for achieving universal health.
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Desenvolvimento Econômico , Política Pública , ChinaRESUMO
Obesity is a risk factor in various types of cancer, including breast cancer. The disturbance of adipose tissue in obesity highly correlates with cancer progression and resistance to standard treatments such as chemo- and radio-therapies. In this study, in a syngeneic mouse model of triple-negative breast cancer (TNBC), diet-induced obesity (DIO) not only promoted tumor growth, but also reduced tumor response to radiotherapy. Serpine1 (Pai-1) was elevated in the circulation of obese mice and was enriched within tumor microenvironment. In vitro co-culture of human white adipocytes-conditioned medium (hAd-CM) with TNBC cells potentiated the aggressive phenotypes and radioresistance of TNBC cells. Moreover, inhibition of both cancer cell autonomous and non-autonomous SERPINE1 by either genetic or pharmacological strategy markedly dampened the aggressive phenotypes and radioresistance of TNBC cells. Mechanistically, we uncovered a previously unrecognized role of SERPINE1 in DNA damage response. Ionizing radiation-induced DNA double-strand breaks (DSBs) increased the expression of SERPINE1 in cancer cells in an ATM/ATR-dependent manner, and promoted nuclear localization of SERPINE1 to facilitate DSB repair. By analyzing public clinical datasets, higher SERPINE1 expression in TNBC correlated with patients' BMI as well as poor outcomes. Elevated SERPINE1 expression and nuclear localization were also observed in radioresistant breast cancer cells. Collectively, we reveal a link between obesity and radioresistance in TNBC and identify SERPINE1 to be a crucial factor mediating obesity-associated tumor radioresistance.
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Neoplasias de Mama Triplo Negativas , Animais , Camundongos , Humanos , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/radioterapia , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Linhagem Celular Tumoral , Reparo do DNA , Obesidade/genética , Obesidade/complicações , Quebras de DNA de Cadeia Dupla , Microambiente Tumoral , Inibidor 1 de Ativador de Plasminogênio/genéticaRESUMO
Cellular stress response is an important adaptive mechanism for regulating cell fate decision when cells confront with stress. During tumorigenesis, tumor progression and the course of treatment, cellular stress signaling can activate subsequent response to deal with stress. Therefore, cellular stress response has impacts on the fate of tumor cells and tumor responsiveness relative to therapeutic agents. In recent years, attention has been drawn to long non-coding RNAs (lncRNAs), a novel class of RNA molecules with more than 200 nucleotides in length, which has little protein-coding potential and possesses various functions in multiple biological processes. Accumulating evidence has shown that lncRNAs are also engaged in the regulation of cellular stress response, particularly in cancers. Here, we summarize lncRNAs that have been reported in the adaptive response to major types of cellular stress including genotoxic, hypoxic, oxidative, metabolic and endoplasmic reticulum stress, all of which are often encountered by cancer cells. Specifically, the molecular mechanisms of how lncRNAs regulate cellular stress response during tumor progression or the development of therapy resistance are emphasized. The potential clinical applications of stress-responsive lncRNAs as biomarkers will also be discussed.
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BACKGROUND: The aim of this study was to evaluate the clinical efficacy of suture-fixation mucopexy in the treatment of prolapsed hemorrhoids. METHODS: A total of 123 patients with grade II, III, and IV hemorrhoids were admitted to The TCM Hospital of Pu Dong New District between 2018 and 2019. They were randomly divided into the suture-fixation group (SF, N.=60) and the Milligan-Morgan hemorrhoidectomy group (MM, N.=63). Clinical efficacy, postoperative pain, average operation time, hospital stay, complications, and patient satisfaction were prospectively evaluated. RESULTS: No significant differences were identified in clinical efficacy; operation time and hospital stay between the two groups (P>0.05). However, VAS Score in the SF group was lower than that in the MM group. And the SF group was also more advantageous in anal function protection (P<0.05). In addition, the results of the follow-up survey revealed no significant difference in postoperative recurrence rate and patient satisfaction (P>0.05). CONCLUSIONS: Compared with Milligan-Morgan hemorrhoidectomy, suture-fixation mucopexy is as effective in the treatment of prolapsed hemorrhoid, but it has more advantages in reducing postoperative pain and protecting the anal function.
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Hemorroidectomia , Hemorroidas , Hemorroidectomia/efeitos adversos , Hemorroidas/cirurgia , Humanos , Dor Pós-Operatória/etiologia , Suturas , Resultado do TratamentoRESUMO
For a better environment and sustainable development of China, it is indispensable to unravel how urban forms (UF) affect the fine particulate matter (PM2.5) concentration. However, research in this area have not been updated consider multiscale and spatial heterogeneities, thus providing insufficient or incomplete results and analyses. In this study, UF at different scales were extracted and calculated from remote sensing land-use/cover data, and panel data models were then applied to analyze the connections between UF and PM2.5 concentration at the city and provincial scales. Our comparison and evaluation results showed that the PM2.5 concentration could be affected by the UF designations, with the largest patch index (LPI) and landscape shape index (LSI) the most influential at the provincial and city scales, respectively. The number of patches (NP) has a strong negative influence (-0.033) on the PM2.5 concentration at the provincial scale, but it was not statistically significant at the city scale. No significant impact of urban compactness on the PM2.5 concentration was found at the city scale. In terms of the eastern and central provinces, LPI imposed a weighty positive influence on PM2.5 concentration, but it did not exert a significant effect in the western provinces. In the western cities, if the urban layout were either irregular or scattered, exposure to high PM2.5 pollution levels would increase. This study reveals distinct ties of the different UF and PM2.5 concentration at the various scales and helps to determine the reasonable UF in different locations, aimed at reducing the PM2.5 concentration.
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Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Cidades , Monitoramento Ambiental , Material Particulado/análiseRESUMO
In order to improve early osseointegration and long-term survival rate of implants, a multifunctional titanium surface that promotes osteogenesis and antibacterial properties is expected. Incorporation of bioactive trace elements such as magnesium ions was proved a promising method to improve osseointegration of titanium. Phytic acid has strong chelating ability with multivalent cations, which has been used in surface modification. Moreover, phytic acid was proved antibacterial potential. Herein, to improve the osteogenic and antibacterial properties, a phytic acid-magnesium (PA-Mg) layer was introduced on titanium using phytic acid as a cross-linker molecule. No obvious changes of the surface characterization were observed by scanning electron microscopy and atomic force microscopy. X-ray photoelectron spectroscopy confirmed that the PA-Mg layer covalently bond to the Ti surface, and the thickness of the PA-Mg layer was about 150 nm. Besides, improved hydrophilic and more protein adsorption were observed on Ti-PA-Mg. Notably, a relatively controlled magnesium release was also observed on Ti-PA-Mg. Human bone mesenchymal stem cells showed better adhesion, proliferation, and osteogenic differentiation on Ti-PA-Mg samples, indicating improved biocompatibility and osteoinductivity. Moreover, Ti-PA-Mg had better antibacterial properties against porphyromonas gingivalis than Ti. Overall, the PA-Mg layer on Ti surface improved the osteogenic and antibacterial properties, which may have promise for use in dental implantation.
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Osteogênese , Titânio , Antibacterianos/farmacologia , Diferenciação Celular , Proliferação de Células , Humanos , Magnésio/farmacologia , Osseointegração , Ácido Fítico/farmacologia , Propriedades de Superfície , Titânio/farmacologiaRESUMO
Currently, whether the urban development in China satisfies Zipf's law across different scales is still unclear. Thus, this study attempted to explore whether China's urban development satisfies Zipf's law across different scales from the National Polar-Orbiting Partnership's Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) nighttime light data. First, the NPP-VIIRS data were corrected. Then, based on the Zipf law model, the corrected NPP-VIIRS data were used to evaluate China's urban development at multiple scales. The results showed that the corrected NPP-VIIRS data could effectively reflect the state of urban development in China. Additionally, the Zipf index (q) values, which could express the degree of urban development, decreased from 2012 to 2018 overall in all provinces, prefectures, and counties. Since the value of q was relatively close to 1 with an R2 value > 0.70, the development of the provinces and prefectures was close to the ideal Zipf's law state. In all counties, q > 1 with an R2 value > 0.70, which showed that the primate county had a relatively stronger monopoly capacity. When the value of q < 1 with a continuous declination in the top 2000 counties, the top 250 prefectures, and the top 20 provinces in equilibrium, there was little difference in the scale of development at the multiscale level with an R2 > 0.90. The results enriched our understanding of urban development in terms of Zipf's law and had valuable implications for relevant decision-makers and stakeholders.