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Pyrometallurgy technique is usually applied as a pretreatment to enhance the leaching efficiencies in the hydrometallurgy process for recovering valuable metals from spent lithium-ion batteries. However, traditional pyrometallurgy processes are energy and time consuming. Here, we report a carbothermal shock (CTS) method for reducing LiNi0.3 Co0.2 Mn0.5 O2 (NCM325) cathode materials with uniform temperature distribution, high heating and cooling rates, high temperatures, and ultrafast reaction times. Li can be selectively leached through water leaching after CTS process with an efficiency of >90 %. Ni, Co, and Mn are recovered by dilute acid leaching with efficiencies >98 %. The CTS reduction strategy is feasible for various spent cathode materials, including NCM111, NCM523, NCM622, NCM811, LiCoO2 , and LiMn2 O4 . The CTS process, with its low energy consumption and potential scale application, provides an efficient and environmentally friendly way for recovering spent lithium-ion batteries.
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The brown planthopper (BPH), Nilaparvata lugens (Stål), is one of the most destructive pests in rice-growing regions of Asia. Extensive studies have suggested that SWI/SNF chromatin remodeling ATPase Brahma (BRM) plays multiple roles in the insect model Drosophila. Yet much less is known about the physiological properties for NlBRM. In the present study, the cloned full-length cDNA of NlBRM was 5637 bp and contained an ORF of 5292 bp encoding a 194.53 kD protein. The spatiotemporal dynamics of NlBRM was investigated by qPCR, which showed that it was abundantly expressed in the egg and ovary. Then significant downregulation of NlBRM by dsRNA injection had a relatively greater impact on female survival than male. Moreover, the number of oviposition marks of the NlBRM-RNAi females were declined by 61.11% - 73.33% compared with the controls during the subsequent 5 days after dsRNA injection. Meanwhile, the number of newly hatched BPH nymphs also decreased correspondingly by 93.56% - 100%. Phenotypic analysis revealed that none of normally banana-shaped eggs were discernable in the ovaries of NlBRM-deficient females, where mRNA expression of N. lugens vitellogenin gene was also reduced. Our results demonstrated that NlBRM played a crucial role in ovarian development and fecundity of BPH, likely by regulating the vitellogenin gene in vivo, which could be as a promising target for parental RNAi-based control of this serious rice pest.
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Adenosina Trifosfatases , Hemípteros , Oryza , Adenosina Trifosfatases/metabolismo , Animais , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , Feminino , Hemípteros/metabolismo , Humanos , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Masculino , Oryza/metabolismo , Interferência de RNA , RNA de Cadeia Dupla/genética , RNA de Cadeia Dupla/metabolismo , Vitelogeninas/genéticaRESUMO
Dietary pattern has been revealed to be associated with metabolic syndrome. However, the association was not well documented in Chinese due to the complexity of Chinese foods. We mainly assessed the dietary patterns and examined their effects on metabolic syndrome among Chinese adults. Four dietary patterns including 'Refined Grains & Vegetables' Pattern, 'Dairy & Eggs' Pattern, 'Organ Meat & Poultry' Pattern, and 'Coarse Grains & Beans' Pattern were extracted. 'Dairy & Eggs' Pattern was associated with a decreased odds of metabolic syndrome in women, and 'Coarse Grains & Beans' Pattern was associated with a decreased odds of hypertension in men. These results provided a scientific basis for future research and dietary guideline perfection.
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Dieta , Comportamento Alimentar , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/etiologia , Adulto , Idoso , Feminino , Alimentos/classificação , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Sepsis induced by Staphylococcus aureus has worse outcome with the appearance of methicillin-resistant Staphylococcus aureus (MRSA) because of multi-resistance to a large group of antibiotics, which may lead to death from septic shock. Pathogenesis of S. aureus infections are involved in the production of a wide variety of virulence factors. MgrA, a noval global regulator, is a member of the MarR (multiple antibiotic resistance regulator)/SarA (staphylococcal accessory regulator A) family proteins, which plays a key role in regulating the expression of major virulence factors in S. aureus. In the present study, by using a murine model of sepsis, we investigated the role of mgrA in onset and progression of S. aureus induced sepsis. We found that mice inoculated with wild-type strain Newman had significantly higher mortality (p = 0.029), more weight lost, more bacterial load in blood, spleen and kidney, more intense inflammation response, and worse histopathology than mice inoculated with mgrA knockout strain. Our results has provided evidence that mgrA is a global regulator in S. aureus, and play an important role in S. aureus sepsis, could increase mortality and accelerate the onset and development of sepsis.
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Proteínas de Bactérias/metabolismo , Progressão da Doença , Sepse/patologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/patogenicidade , Fatores de Virulência/metabolismo , Animais , Carga Bacteriana , Proteínas de Bactérias/genética , Sangue/microbiologia , Peso Corporal , Modelos Animais de Doenças , Técnicas de Inativação de Genes , Rim/microbiologia , Masculino , Camundongos Endogâmicos BALB C , Sepse/microbiologia , Baço/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Análise de Sobrevida , Fatores de Virulência/genéticaRESUMO
We report here the electrochemistry, spectroscopy, and electrogenerated chemiluminescence (ECL) from a solution, film, and nanoparticles (NPs) of a red-emitting dithienylbenzothiadiazole molecular fluorophore [4,7-bis(4-(n-hexyl)-5-(3,5-di(1-naphthyl)phenyl)thiophen-2-yl)-2,1,3-benzothiadiazole, 1a], which has a donor-acceptor-donor configuration. In addition, the quenching of the fluorescence of the organic NPs by KI was investigated. The 1a film and NPs exhibit two absorbance peaks at 350 and ~504 nm that are red-shifted compared to those of 1a dissolved in solution (340 and 486 nm). Fluorescence quenching of 1a NPs does not follow a linear Stern-Volmer relationship; i.e., the fluorescence emission with excitation wavelength at either 350 or 504 nm decreased with increasing concentration of KI. Static quenching and heterogeneity related to the size distribution of the 1a NPs are proposed to explain the nonlinearity. A lifetime of 4.49 ± 0.04 ns was found for 1a organic NPs in water saturated with N2. After addition of KI, the fluorescence lifetime decreased to 3.1 ns. The fluorescence emission of 1a film/NPs is red-shifted (~17 nm) compared with that of 1a solution in dichloromethane (DCM). Solution ECL was generated in DCM through an annihilation reaction, while film and NP ECL could be generated in water through oxidation with a coreactant, tri-n-propylamine (TPrA). A film of 1a with thickness of 100-900 nm was prepared by drop-casting 1a in DCM on fluorine-doped tin oxide, and the ECL of the 1a film was found in phosphate-buffered saline solution with TPrA. Both 1a in solution and the 1a film produce strong ECL (I(film) = 0.14I(solution)). The ECL spectrum of 1a in solution, produced by electron-transfer annihilation of the reduced and oxidized forms, consists of a single peak with maximum emission at about 637 ± 4 nm, ~20 nm red-shifted from its fluorescence, while the ECL spectrum of 1a film produced by reaction with TPrA consists of a single peak with maximum emission at 642 ± 3 nm, a 10 nm red shift compared with the fluorescence of 1a film. Organic fluorescent 1a NPs were prepared by a reprecipitation method in water saturated with N2, and they were characterized by transmission electron microscopy, absorbance, fluorescence, and ECL. Strong ECL was also generated from the organic NPs in water by reduction with K2S2O8 coreactant.
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Novel supramolecular phosphorescent polymers (SPPs) are synthesized as a new class of solution-processable electroluminescent emitters. The formation of these SPPs takes advantage of the efficient non-bonding assembly between bis(dibenzo-24-crown-8)-functionalized iridium complex monomer and bis(dibenzylammonium)-tethered co-monomer, which is monitored by (1) H NMR spectroscopy and viscosity measurements. These SPPs show good film morphology and an intrinsic glass transition with a Tg of 94-116 °C. Noticeably, they are highly photoluminescent in solid state with quantum efficiency up to ca. 78%. The photophysical and electroluminescent properties are strongly dependent on the molecular structures of the iridium complex monomers.
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Complexos de Coordenação/química , Irídio/química , Polímeros/química , Medições Luminescentes , Polímeros/síntese química , Temperatura de Transição , ViscosidadeRESUMO
This tutorial review presents some recent developments in the design, synthesis and implementation of organic solution-processable molecular fluorophores for non-doped electroluminescent [corrected] devices. After a brief presentation of the basic principles of operation and main characteristics of electroluminescent devices, some examples of active emitters representative of the main classes of non-doped molecular electrofluorophores will be discussed. Emphasis is placed on the relationships between the molecular structure and the electronic properties of molecular emitters, in which high photoluminescence efficiency, synthetic accessibility and processability are combined by design with additional functions such as hole and/or electron injection and transport.
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This study explored the regulation of different perfusion methods on ischemia-reperfusion injury in donor kidneys. In this study, renal cortical/medullary tissue specimens were collected from porcine kidneys donors using different perfusion methods at various time points. Hematoxylin and eosin (H&E) staining was used to test the histological differences. Differentially expressed micro-ribonucleic acids (miRNAs) were identified by miRNA transcriptome sequencing. Reverse transcription-polymerase chain reaction (RT-PCR) tests were used to verify the changes in miRNAs in the kidney tissue taken from different perfusion groups. The related signaling pathways and the changes in the cell functions of different perfusion groups were analyzed by Kyoto Encyclopedia of Genes and Genomes (KEGG) /Gene Ontology (GO) bioinformatics analyses. The effects of miRNA overexpression on the metabolism and proliferation of HK2 cells were detected by ATP kit and MTT assay. The H&E staining results showed that there were essentially no differences in the tissue samples among different perfusion groups at and before 12 h compared with a control group. The quantitative PCR results revealed that there was essentially no change in the expression of ssc-miR-451, ssc-miR-1285, and ssc-miR-486 in the cis infusion or joint infusion kidney groups, and their expression was significantly down-regulated over time in the trans-infusion kidney group. The bioinformatics analysis showed that the cellular component, molecular function, and biological processes of the kidney tissue, which had been perfused using three methods, had been consistently affected. The most significant changes after perfusion occurred in the intracellular metabolism signaling pathways. Furthermore, the energy metabolism and proliferation of the HK2 cells were significantly inhibited after the overexpression of miR-451. Specific miRNA markers, such as miR-451, may play a negative regulatory role in cell metabolism following the perfusion of kidney transplants using different methods.
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Trifosfato de Adenosina , MicroRNAs , Trifosfato de Adenosina/metabolismo , Animais , Proliferação de Células/genética , Rim/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Perfusão , SuínosRESUMO
OBJECTIVE: The present study aimed to observe and discuss the effectiveness and safety of the UreTron single-probe ultrasonic intracorporeal lithotripter in ureteroscopic lithotripsy. METHODS: The clinical data of patients with unilateral solitary ureteral calculi treated with ureteroscopic lithotripsy who were hospitalized at the Department of Urology (West District) of Beijing Chaoyang Hospital between March 2016 and August 2020 were selected for retrospective analysis. The patients were divided into the UreTron group (group U) and holmium laser group (group H) according to the lithotripsy method adopted. The operation duration, length of hospital stay, stone clearance rate, proportion of patients requiring flexible ureteroscopy-assisted lithotripsy, and complications were compared between the groups. RESULTS: There was no statistical difference between the groups in terms of the general characteristics, operation duration, or length of hospital stay (P > 0.05). Regarding the stone clearance rate (group U=93.5%; group H=75%), proportion of patients requiring flexible ureteroscopy-assisted lithotripsy (group U=6.5%; group H=27.8%), and incidence of surgical complications (group U=1 case; group H=9 cases), group U was superior to group H, and the differences between the groups were statistically significant (P < 0.05). However, the differences in other complications (cardiocerebral complications and lower extremity thrombosis) were not statistically significant between the groups (P > 0.05). CONCLUSION: The UreTron system is a new lithotripsy apparatus that is safe and effective for ureteroscopic lithotripsy and has certain advantages in terms of the stone clearance rate, proportion of patients requiring flexible ureteroscopy-assisted lithotripsy, and surgical complications, making it worthy of clinical application.
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INTRODUCTION: Laparoscopic renal cyst decortication is currently the best choice for the treatment of simple renal cysts and is widely used in clinical practice. AIM: To investigate the safety and clinical efficacy of two-trocar mini-laparoscopic decortication of adult renal cysts. MATERIAL AND METHODS: A total of 90 patients were enrolled in the study and randomly divided into two groups: a two-trocar mini-laparoscopic treatment group (M group) and a three-trocar standard laparoscopic treatment group (S group), with 45 patients in each group. RESULTS: The average length of hospital stay was shorter, and the demand for postoperative analgesics was less in the M group than in the S group (p < 0.05). The proportion of "very satisfied" patients in the patient physical recovery satisfaction survey was significantly higher in the M group than in the S group (p < 0.05). Of the 45 patients in the M group, 40 successfully underwent surgery. In 3 patients, the two-trocar procedure was converted to a three-trocar procedure due to difficulty in separating perirenal adhesion for visualization. Mini-laparoscopic surgery was converted to classic laparoscopic surgery in 2 patients. In the S group, 44 patients successfully underwent the renal cyst decortication procedure. One patient underwent partial renal resection due to an intraoperative diagnosis of multilocular cystic renal cell carcinoma. Postoperative urine leakage was reported in 3 patients in the M group and two in the S group. CONCLUSIONS: Two-trocar mini-laparoscopic treatment of renal cysts is as safe and effective as traditional laparoscopy but is associated with less cosmetic damage, leading to a better physical appearance.
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G-quadruplex DNA (G4DNA) structure, which widely exists in the chromosomal telomeric regions and oncogenic promoter regions, plays a pivotal role in extending telomeric DNA with the help of telomerase in human cells. Bloom (BLM) helicase, a crucial member of the family of genome surveillance proteins, plays an essential role in DNA metabolic and repair pathways, including DNA replication, repair, transcription, recombination during chromosome segregation, and assuring telomere stability. The unwinding of G4DNA requires the participation of DNA helicase, which is crucial for maintaining chromosomal stability in cancer cells. Using fluorescence polarization and the electrophoretic mobility shift assay (EMSA), this study aimed to investigate the DNA-binding and unwinding properties of BLM helicase, cloned and purified from prostate cancer cells, toward G4DNA. The results revealed that BLM helicase derived from prostate cancer cells could bind and unwind G4DNA. The molecular affinity of bond between G4DNA and the helicase was dependent on the single-stranded DNA (ssDNA) terminals in G4DNA; the helicase was effectively bound to the G4DNA when the helicase monomer sufficiently covered approximately 10 nucleotides at the 3' or 5' ssDNA tail of G4DNA. For the unwinding of G4DNA, there was an apparent requirement of a 3' ssDNA tail and ATP; a G4DNA with only a 3' ssDNA tail was identified to be the most suitable substrate to be unwound by BLM helicase and required 3' ssDNA tails of at least 10 nt in length for efficient unwinding. Besides, BLM helicase was loosely bound and partly unwound the blunt-ended G4DNA. Although further mechanistic studies are warranted, the experimental results presented in this study are beneficial to further our understanding of the functional implication of BLM helicase in prostate cancer cells.
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DNA/química , Quadruplex G , Neoplasias da Próstata/metabolismo , RecQ Helicases/metabolismo , Telômero/metabolismo , DNA/genética , DNA/metabolismo , DNA de Cadeia Simples/química , DNA de Cadeia Simples/genética , DNA de Cadeia Simples/metabolismo , Humanos , Cinética , Masculino , Modelos Moleculares , Conformação de Ácido Nucleico , Células PC-3 , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Ligação Proteica , RecQ Helicases/genética , Especificidade por Substrato , Telômero/genéticaRESUMO
Objective: To investigate the safety and efficacy of a vascular prop device for laparoscopic orthotopic kidney transplantation (LOKT) in swine. Material and Methods: Twenty swine were randomly divided into two groups. A vascular prop device was used in the observation (VP) group, and the vein beltization technique was used in the control (VB) group. The right kidney, as a donor graft, was laparoscopically transplanted to the location of the left kidney after a left nephrectomy. Data on the operative time, venous anastomotic time, vein stenosis, etc., and the survival of the swine in the two groups were recorded. Results: The mean transplant operative time, the mean cold ischemia time, and the venous anastomotic times in the VP group were significantly shorter than those in the VB group. Seven swine in the VP group and three swine in the VB group survived for 7 days. Autopsy results showed the occurrence of one artery stenosis and one vein stenosis in the VP group and one artery stenosis and five vein stenoses in the VB group. The median survival time was 6.25 days for the swine in the VP group and 4.40 days for those in the VB group. Conclusions: The vascular prop device is safe and feasible for LOKT in swine and may accelerate venous anastomosis and ensure the quality of venous anastomotic stoma.
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We report here the electrochemistry and electrogenerated chemiluminescence (ECL) of a red-emitting dithienylbenzothiadiazole-based molecular fluorophore (4,7-bis(4-(4-sec-butoxyphenyl)-5-(3,5-di(1-naphthyl)phenyl)thiophen-2-yl)-2,1,3-benzothiadiazole, 1b). 1b contains two substituted thiophene groups as strong electron donors at the ends connected directly to a strong electron acceptor, 2,1,3-benzothiadiazole, in the center. Each thiophene moiety is substituted in position 2 by 3,5-di(1-naphthyl)phenyl and in position 3 by 4-sec-butoxyphenyl. Cyclic voltammetry of 1b, with scan rate ranging from 0.05 to 0.75 V/s, shows a single one-electron reduction wave (E°(red) = -1.18 V vs SCE) and two nernstian one-electron oxidation waves (E°(1,ox) = 1.01 V, E°(2,ox) = 1.24 V vs SCE). Reduction of the unsubstituted 2,1,3-benzothiadiazole center shows nernstian behavior with E°(red) = -1.56 V vs SCE. By comparison to a digital simulation, the heterogeneous electron-transfer rate constant for reduction, k(r)° = 1.5 × 10(-3) cm/s, is significantly smaller than those for the oxidations, k(o)° > 0.1 cm/s, possibly indicating that the two substituted end groups have a blocking effect on the reduction of the benzothiadiazole center. The ECL spectrum, produced by electron-transfer annihilation of the reduced and oxidized forms, consists of a single peak with maximum emission at about 635 nm, consistent with the fluorescence of the parent molecule. Relative ECL intensities with respect to 9,10-diphenylanthracene are 330% and 470% for the radical anion-cation and radical anion-dication annihilation, respectively. Radical anion (A(-â¢))-cation (A(+â¢)) annihilation produced by potential steps shows symmetric ECL transients during anodic and cathodic pulses, while for anion (A(-â¢))-dication (A(2+â¢)) annihilation, transient ECL shows asymmetry in which the anodic pulse is narrower than the cathodic pulse. Digital simulation of the transient ECL experiments showed that the origin of the observed asymmetry is asymmetry in the amount of generated charges rather than instability of the electrogenerated species.
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Eletroquímica/métodos , Tiadiazóis/química , Ânions , Cátions , Cinética , LuminescênciaRESUMO
Organic-inorganic hybrid perovskites have attracted considerable attention due to their superior optoelectronic properties. Traditional one-step solution-processed perovskites often suffer from defects-induced nonradiative recombination, which significantly hinders the improvement of device performance. Herein, treatment with green antisolvents for achieving high-quality perovskite films is reported. Compared to defects-filled ones, perovskite films by antisolvent treatment using methylamine bromide (MABr) in ethanol (MABr-Eth) not only enhances the resultant perovskite crystallinity with large grain size, but also passivates the surface defects. In this case, the engineering of MABr-Eth-treated perovskites suppressing defects-induced nonradiative recombination in perovskite solar cells (PSCs) is demonstrated. As a result, the fabricated inverted planar heterojunction device of ITO/PTAA/Cs0.15 FA0.85 PbI3 /PC61 BM/Phen-NADPO/Ag exhibits the best power conversion efficiency of 21.53%. Furthermore, the corresponding PSCs possess a better storage and light-soaking stability.
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An ionic molecular glass based on a dendronized monoammonium salt has been facilely synthesized and utilized as an interfacial electron-injection layer in a light-emitting diode (LED). The characterization of a yellow-green LED that involves an Al cathode and a thin layer of the new compound spin cast from a methanol solution has shown device performances comparable to those obtained with a Ba/Al cathode. Photovoltaic measurements under white light irradiation reveal that a thin layer of the new compound can significantly increase the built-in potential and thus facilitate electron injection from an Al cathode. Furthermore, it is interesting to observe that the new ionic salt could undergo reorganization on the emissive conjugated polymer layer, which leads to the formation of nearly uniform nanoaggregates.
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Water use efficiency (WUE) is an important index to evaluate plant drought resistance. Studying the dynamics of WUE and its influencing factors can provide reference for the vegetation restoration in Beijing mountainous area. We measured WUE of Platycladus orientalis in growing season and investigated the influence of meteorological factors, soil factors, and atmospheric CO2 concentration on WUE, based on the stable carbon isotope techniques. The results showed that: 1) The short-term WUE decreased and then increased in the growing season, with minimum value (2.69 mmol·mol-1) in July and maximum value (13.88 mmol·mol-1) in October. 2) The vapor pressure deficit (VPD) had the most significant impacts on WUE, followed by air temperature (Ta), soil moisture (Ms), relative humidity (RH), and atmospheric CO2 concentration (Ca), explaining 89.7% of the total variance. Solar radiation (Ra) and wind speed (Ws) had no impacts on WUE. 3) VPD and Ta are the most two important factors influencing short-term WUE, explaining 53.9% of the total variance. The effects of VPD on short-term WUE was higher than that of Ta. Ms and RH were the second important factors of the short-term WUE, explaining 25.4% of the total variance. The effects of Ms on short-term WUE was higher than that of RH. Ca had little effect on the short-term WUE and could explain 10.3% of the total variance.
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Solo , Água , Pequim , TemperaturaRESUMO
As an important component of terrestrial ecosystem carbon cycle, soil respiration is a hot topic in the studies of carbon cycle. The temperature sensitivity (Q10) of soil respiration is a critical index to estimate the effects of global warming on soil respiration. Understanding Q10 of different vegetation types is of important significance for assessing the carbon budget of forest ecosystems. We examined soil respiration and its temperature sensitivity in three typical forests (Pinus tabuliformis, Platycladus orientalis, and Quercus variabilis) in the Beijing mountainous area by measuring the soil physical and chemical properties, soil temperature, soil moisture, and soil respiration rate (Rs) during the growing season. The results showed that Rs of three typical vegetation types showed a similar trend with changes of soil temperature and humidity, which showed a unimodal pattern, with minimum value (0.45 µmol·m-2·s-1) in early April and maximum value (3.95 µmol·m-2·s-1) in early July. There were significant differences in Rs and Q10 values among the three vegetation types. Soil temperature and humidity were the important factors affecting soil respiration, together they could explain the seasonal variation of soil respiration rate from 48.1% to 56.7%. The range of Q10 value was between 2.05 and 3.19. There was a significant negative correlation between soil organic carbon content and Q10 under each vegetation type (R2>0.9). Vegetation type, elevation, and soil organic carbon content were important drivers for the variation of Q10.
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Ciclo do Carbono , Monitoramento Ambiental , Solo/química , Temperatura , Pequim , ChinaRESUMO
It has been challenging to develop deep blue organic molecular fluorescent emitters with CIE y (yâ¯≤â¯0.08) based on triplet-triplet annihilation (TTA). Here, we report facilely available dianthracenylphenylene-based emitters, which have a 3,5-di(4-t-butylphenyl)phenyl moiety at the one end and 4-cyanophenyl or 3-pyridyl at the other end, respectively. Both fluorophores show a high glass transition temperature of over 220⯰C with a thermal decomposition temperature of over 430⯰C at an initial weight loss of 1%. The preliminary characterizations of the organic light-emitting diodes (OLEDs) that utilized these nondoped emitters provided high EQEs of 4.6%-5.9% with CIE coordinates (0.15, 0.07-0.08). The analysis of the EL transient decay revealed that TTA contributed to the observed performance. The results show that the new emitters are attractive as a potential TTA-based host to afford stable deep blue fluorescent OLEDs.
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There has been an increasing demand for high-performance and cost-effective organic electron-transport materials for organic light-emitting diodes (OLEDs). In this contribution, we present a simple compound 3-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-1,10-phenanthroline through the facile Pd-catalyzed coupling of a triphenyltriazine boronic ester with 3-bromo-1,10-phenanthroline. It shows a high Tg of 112⯰C. The ultraviolet photoelectron spectroscopy measurements reveal a deep HOMO level of -6.5â¯eV. The LUMO level is derived as -3.0â¯eV, based on the optical bandgap. The low-temperature solid-state phosphorescent spectrum gives a triplet energy of â¼2.36â¯eV. n-Doping with 8-hydroxyquinolatolithium (Liq, 1:1) leads to considerably improved electron mobility of 5.2â¯×â¯10-6-5.8â¯×â¯10-5â¯cm2â¯V-1â¯s-1 at Eâ¯=â¯(2-5)â¯×â¯105â¯Vâ¯cm-1, in contrast with the triarylphosphine oxide-phenantroline molecular conjugate we reported previously. It has been shown that through optimizing the device structure and hence suppressing polaron-exciton annihilation, introducing this single Liq-doped electron-transport layer could offer high-efficiency and stable phosphorescent OLEDs.
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OBJECTIVE: To investigate the antimicrobial resistance among the nosocomial gram-negative pathogens from 15 teaching hospitals located in different areas in China in 2005. METHODS: A total of 1927 non-repetitive nosocomial gram-negative pathogens were collected from 15 teaching hospitals in different areas in China and sent to the central lab for reidentification and susceptibility testing. The levels of minimal inhibitory concentration (MIC) of 18 antimicrobial agents were determined by agar dilution method. WHONET 5.4 software was used to analyze the data. RESULTS: The strains of Escherichia coli, Klebsiella pneumoniae, and Proteous mirabilis isolates that did not produce extended spectrum beta lactamases (ESBLs) showed high sensitivity to beta-lactams. The antibiotics with a susceptibility rates over 80% against the strains of Entorobacter cloacae, Enterobacter aerogene, Citrobacter spp, Serratia spp, and Proteous vulgaris producing AmpC enzyme included meropenem, imipenem, and piperacillin-tazobactam, and these 3 drugs showed a susceptibility rate of more than 80% against the ESBL-producing strains of Escherichia coli and Klebsiella pneumoniae. Other antimicrobial agents showing a relatively high activity against Enterobacter spp, Citrobacter spp, Serratia spp and Proteous vulgaris included cefepime (67.3% - 100%), amikacin (67.3% - 95.2%), ceftazidime (52.9% - 100%) and cefoperazone-sulbactam (51.9% - 100%). The susceptibility rate of fluoroquinolones was 34.8% - 36.1% against non-ESBL-producing Escherichia coli and was 13.4% - 17.1% against ESBL-producing isolates. The most active agent against Pseudomonas aeruginosa was polymyxin B (95.6%). The agents with the activity rates of 70% - 80% included meropenem, imipenem, amikacin, and piperacillin-tazobactam. The antibiotic with a high susceptible rate against Acinetobacter baumannii was polymyxin B (98.3%), followed by imipenem (80.8%), meropenem (76.2%), and minocycline (67.4%). The susceptible rates of other agents were all below 60%. The agents with relatively high activity against Stenotrophomonas maltophilia included minocycline (85%), levofloxacin (82.5%), and trimethoprim-sulfamethoxazole (77.5%). The agents with a relatively high activity against Burkholderia cepacia included minocycline (77.2%) and meropenem (61.4%). CONCLUSION: Carbapenem, piperacillin-tazobactam, amikacin and cefepime remained relatively high activity against nosocomial Enterobacteriaceae, Non-fermenting pathogens have lower susceptibility to the antimicrobial agents than before.