Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 305
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Inorg Chem ; 63(27): 12615-12623, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38917336

RESUMO

Polynitrogen has been widely studied recently as a rising star of high energy density materials. Here, we performed a systematic study of the Zr-N compounds in the N-rich region by the first-principles method. The high-pressure phase diagram of the Zr-N system is enriched by proposing five new compounds. ZrN10 with the infinitely extended band shaped structure is first reported. The band-like polynitrogen of ZrN10 decomposes into a more stable chain-like polynitrogen structure under the influence of temperature. Additionally, the novel honeycomb-like band-shaped N10 structure hcb-N10 has been discovered by removing the Zr atoms. The absence of the -4 oxidation state in the N10 unit prompts its further polymerization, which makes hcb-N10 possess dynamical and thermal stability in ambient conditions. hcb-N10 is a semiconductor with a bandgap of 2.97 eV due to highly localized electrons. Both chain-ZrN10 and hcb-N10 represent potential candidates for HEDMs with outstanding energy and explosive performance.

2.
Phys Chem Chem Phys ; 26(12): 9601-9607, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38465792

RESUMO

Four high-pressure N-rich compounds (Pmn21-CeN7, Amm2-CeN9, P1̄-CeN10, and P1̄-II-CeN10) are proposed using first-principles calculations. Novel polymeric units (a heart shaped layered structure, chain-like N8 rings, and two new banded structures) in four cerium nitrides are reported for the first time in this study. The analyses of electronic structures and bonding properties show that the charge transfer between Ce and N atoms promotes the formation of the Ce-N ionic bond and N-N covalent bond, which play an important role in stabilizing the nitrogen skeleton. Four new phases possess high energy densities (3.24-3.86 kJ g-1), indicating that they are favorable high-energy density materials. Moreover, P1̄-CeN10 possesses ultra-incompressibility along the [1 0 0] direction. Finally, infrared and Raman spectra are analyzed to provide guidance for experimental synthesis.

3.
J Chem Phys ; 160(7)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38375907

RESUMO

The catalytic hydrogenation of biomass-derived chemicals is essential in chemical industry due to the growing demand for sustainable and renewable energy sources. In this study, we present a comprehensive theoretical investigation regarding the hydrogenation of glycolaldehyde to ethylene glycol over a Ru/C catalyst by employing density functional theory and ab initio molecular dynamics simulations. With inclusion of explicit solvation, we have demonstrated that the glycolaldehyde hydrogenation is significantly improved due to the fast proton transfer through the hydrogen bond network. The enhanced activity could be attributed to the participation of the solvent water as the hydrogen source and the highly positively charged state of a Ru cluster in an aqueous phase, which are critical for the activation of aldehyde groups and proton-assisted hydrogenation. Overall, our findings provide valuable insights into glycolaldehyde hydrogenation over Ru/C catalysts in the aqueous phase, highlighting the importance of solvation effects in the biomass conversion.

4.
Chemphyschem ; 24(13): e202300207, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37089002

RESUMO

The organic salt chlorocholine perchlorate [ClCH2 CH2 N(CH3 )3 ⋅ClO4 ] (CCP) is found to be a molecular ferroelectric with a high theoretical spontaneous polarization (Ps) value up to 17.09 µC cm-2 . CCP exhibits two successive order-disorder phase transition at 332 and 365 K with space groups changing from Cc to Cmc21 and then P63 /mmc, accompanied by unusual two-step ladder-like dielectric, SHG signal with obvious "on/off" contrasts. These findingings provides a further instance of exploring successive thermal-stimuli multi-responsive switching materials applied as switches and sensors.

5.
Inorg Chem ; 62(29): 11674-11681, 2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37417932

RESUMO

Two high-pressure stable phases (I41/a-CeN4 and R3̅m-CeN6) and two metastable phases (P6mm-CeN14 and P6mm-CeN17) were proposed in Ce-N compounds at 150-300 GPa. The polymeric nitrogen units include quadruple helical chains, N6 rings, and first reported layered molecular sieves structures. I41/a-CeN4 can be quenched to ambient conditions and its thermal stability can be maintained up to 500 K. P6mm-CeN14 is dynamically and mechanically stable at ambient pressure. The electronic properties analyses show that charge transfer between the Ce and N atoms makes a significant contribution to the structural stability by promoting the formation of Ce-N ionic bond and N-N covalent bond. The Ce atom provides a suitable coordination environment and an excellent bonding state for the fully sp3 hybridized layered molecular sieve to enhance the stability of P6mm-CeN14. Surprisingly, the energy density (8.45 kJ/g) and explosive performance of P6mm-CeN14 are the highest among all metal polynitrides, refreshing a new record for high-energy metal polynitrides.

6.
Phys Chem Chem Phys ; 25(29): 20009-20014, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37461814

RESUMO

The prediction of the high-pressure structure of the ScNx system enriches the phase diagram of the Sc-N system: three metastable phase structures (P1̄-ScN8, P1-ScN9 and P1-ScN11) are proposed in the N-rich region. These structures have novel polymeric nitrogen structures, and enrich the structural types of polymeric nitrogen under pressure. Interestingly, the P1-ScN11 phase can be quenched to ambient conditions, and release energy at a relatively mild temperature of 800 K. The larger charge transfer plays an important role in the structural stability by inducing the Sc-N ionic bond interaction and N-N covalent bond interaction. The prominent energy properties of P1̄-ScN8, P1-ScN9 and P1-ScN11 make them potential candidates in the application of propellants and explosives.

7.
Anesth Analg ; 137(1): 87-97, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-36944111

RESUMO

BACKGROUND: Emerging evidence has uncovered a vital role of nucleus accumbens (NAc) neurons that express the dopamine D1 receptor (D1R) and its upstream neural circuit in general anesthesia (GA) regulation. However, the underlying downstream neural basis of the modulation of GA emergence by NAc D1R neurons remains unknown. In the present study, we explored the downstream neural mechanism of NAc D1R neurons in the modulation of emergence from sevoflurane GA. METHODS: We traced the axonal projections of NAc D1R neurons using a cell type-specific anterograde tracing method and immunohistochemical techniques in D1R-Cre mice. Optogenetic stimulations combined with electroencephalogram/electromyogram recordings and behavioral tests were used to determine the effects of optogenetic activation of the axonal terminals of NAc D1R neurons on sevoflurane emergence during sevoflurane-induced continuous, steady-state general anesthesia (CSSGA) or burst-suppression oscillations. RESULTS: Labeled efferent fibers of NAc D1R neurons were highly distributed in the ventral pallidum (VP), lateral hypothalamus (LH), and substantia nigra pars compacta. Optogenetic activation of the NAc D1R -VP circuit during CSSGA with sevoflurane induced cortical activation (mean ± standard deviation [SD]; delta power: prestimulation versus during stimulation, 48.7% ± 5.7% vs 35.1% ± 3.3%, P < .0001; beta power: 7.1% ± 2.7% vs 14.2% ± 3.3%, P = .0264) and behavioral emergence, and restored the righting reflex in 66.7% of ChR2 mice. Optogenetic stimulation of the NAc D1R -LH circuit also produced cortical activation (delta power: prestimulation versus during stimulation, 45.0% ± 6.5% vs 36.1% ± 4.6%, P = .0016) and behavioral emergence, and restored the righting reflex in 100% of the ChR2 mice during CSSGA with sevoflurane. Under a sevoflurane-induced burst-suppression state, NAc D1R -VP/LH circuit activation produced evidence of cortical activation (burst-suppression ratio [BSR]: NAc D1R -VP circuit, prestimulation versus during stimulation, 42.4% ± 4.0% vs 26.3% ± 6.0%, P = .0120; prestimulation versus poststimulation, 42.4% ± 4.0% vs 5.9% ± 5.6%, P = .0002; BSR: NAc D1R -LH circuit, prestimulation versus during stimulation, 33.3% ± 13.4% vs 5.1% ± 4.9%, P = .0177; prestimulation vs poststimulation, 33.3% ± 13.4% vs 3.2% ± 4.0%, P = .0105) and behavioral emergence. CONCLUSIONS: Both NAc D1R -VP and NAc D1R -LH circuits are sufficient to promote reanimation from sevoflurane GA by simultaneously inducing cortical and behavioral emergence.


Assuntos
Prosencéfalo Basal , Região Hipotalâmica Lateral , Camundongos , Animais , Sevoflurano , Região Hipotalâmica Lateral/metabolismo , Prosencéfalo Basal/metabolismo , Receptores de Dopamina D1/metabolismo , Anestesia Geral
8.
Int J Clin Pharmacol Ther ; 61(3): 129-138, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36458443

RESUMO

OBJECTIVE: To evaluate the pharmacokinetics (PK), safety, and bioequivalence of two formulations of apixaban in healthy Chinese subjects under fasting and fed conditions. MATERIALS AND METHODS: A single-center, randomized, open, single-dose, two-period crossover PK study was carried out under fasting and fed conditions in 64 healthy subjects enrolled in either the fasting (36 subjects) or the fed (28 subjects) arms of the study. Subjects received a single oral dose of 2.5 mg apixaban tablets as test (T) or reference (R) formulation. The primary PK parameters determined were the area under the plasma concentration-time curve from zero to t and ∞ (AUC0-t and AUC0-∞) and the maximal plasma concentration (Cmax). Safety was assessed mainly from the occurrence of adverse events (AEs). RESULTS: A single drop-out in the fed arm of the trial was excluded from the statistical evaluation. The 90% confidence intervals (CIs) for the geometric mean ratio (GMR) for T/R using AUC0-t were 95.4 - 100.9% and 97.8 - 103.8%, and for AUC0-∞ were 95.3 - 100.6% and 98.3 - 104.3% under fasting (36 subjects) and fed (27 subjects) conditions, respectively. Similarly, the 90% CIs for Cmax were 94.6 - 103.1% and 88.8 - 102.0% under fasting (36 subjects) and the fed (27 subjects) conditions, respectively. Therefore, the 90% CIs for the T/R AUC and Cmax ratios were within the standard range for bioequivalence (80.0 - 125.0%). There were no serious adverse events (SAEs). CONCLUSION: The test and reference 2.5 mg apixaban tablets were bioequivalent and both showed good tolerability and safety.


Assuntos
População do Leste Asiático , Pirazóis , Piridonas , Equivalência Terapêutica , Humanos , Área Sob a Curva , Estudos Cross-Over , Jejum , Voluntários Saudáveis , Comprimidos , Pirazóis/farmacocinética , Piridonas/farmacocinética
9.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(5): 448-456, 2023 May 15.
Artigo em Zh | MEDLINE | ID: mdl-37272169

RESUMO

OBJECTIVES: To investigate the prevalence rate of non-alcoholic fatty liver disease (NAFLD) in overweight/obese children who visit a hospital, and to explore the influencing factors of NAFLD, in order to provide a basis for the prevention of NAFLD in overweight/obese children. METHODS: Overweight/obese children who visited Hunan Children's Hospital from June 2019 to September 2021 were recruited. The prevalence rate of NAFLD was examined. Logistic regression analysis was used to explore the factors influencing the development of NAFLD [non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH)]. Receiver operating characteristic curve analysis was used to evaluate the predictive value of the influencing factors for NAFL and NASH. RESULTS: A total of 844 overweight/obese children aged 6-17 years were enrolled. The prevalence rate of NAFLD in overweight/obese children was 38.2% (322/844), among which the prevalence rates of NAFL and NASH were 28.8% (243/844) and 9.4% (79/844), respectively. Multivariate logistic regression analysis showed that the increase of waist-to-hip ratio (WHR) and low high-density lipoprotein cholesterol (HDL-C) were associated with the development of NAFL and NASH (P<0.05). The receiver operating characteristic curve analysis showed that the combined measurement of WHR and HDL-C had a predictive value for NAFL (area under the curve: 0.653, 95%CI: 0.613-0.694), and for NASH (area under the curve: 0.771, 95%CI: 0.723-0.819). CONCLUSIONS: The prevalence rate of NAFLD in overweight/obese children who visit a hospital is high. WHR and HDL-C are associated with the development of NAFLD and the combined measurement of WHR and HDL-C has a certain value for predicating the development of NAFLD.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Obesidade Infantil , Criança , Humanos , HDL-Colesterol , Estudos Transversais , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/complicações , Sobrepeso/complicações , Obesidade Infantil/complicações , Obesidade Infantil/epidemiologia , Prevalência , Adolescente
10.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(10): 1059-1065, 2023 Oct 15.
Artigo em Zh | MEDLINE | ID: mdl-37905764

RESUMO

OBJECTIVES: To investigate the potential relationship between age and Streptococcus pneumoniae vaccination coverage in kindergarten children, and to provide a basis for guiding vaccination and developing new protein vaccines. METHODS: The stratified cluster random sampling method was used to select 1 830 healthy children from six kindergartens in Shunde District, Foshan City, China, and nasopharyngeal swabs were collected for the isolation and identification of Streptococcus pneumoniae. The logistic regression model based on restricted cubic spline was used to analyze the dose-response relationship between age and Streptococcus pneumoniae vaccination coverage. RESULTS: The rate of nasal Streptococcus pneumoniae carriage was 22.46% (411/1 830) among the kindergarten children, with the predominant serotypes of 6B, 19F, 15A, 23A, 34, and 23F. The coverage rates of 10-valent pneumococcal conjugate vaccine (PCV10) and 13-valent pneumococcal conjugate vaccine (PCV13) were 53.0% and 57.9%, respectively, and there was a significant non-linear dose-response relationship between age and the coverage rates of PCV10 and PCV13 (P<0.05), with a higher coverage rate of PCV10 (88.0%) and PCV13 (91.1%) in the children aged 2 years. There was a significant non-linear dose-response relationship between age and the coverage rates of pilus islet 1 (PI-1) and pilus islet 2 (PI-2) (P<0.05), with a lower vaccination coverage rate for PI-1 (37.7%) and PI-2 (16.1%). The coverage rates of PI-1 (13.0%-58.5%) and PI-2 (6.0%-29.4%) were lower in all age groups. The virulence genes lytA (99.5%) and ply (99.0%) associated with candidate protein vaccines showed higher vaccination coverage rates. CONCLUSIONS: There is a significant non-linear dose-response relationship between the age of kindergarten children and the coverage rates of PCV10 and PCV13 serotypes, and kindergarten children aged 2 years have a relatively high coverage rate of PCV. The high prevalence of the virulence genes lytA and ply shows that they are expected to become candidate virulence factors for the development of a new generation of recombinant protein vaccines.


Assuntos
Infecções Pneumocócicas , Streptococcus pneumoniae , Humanos , Criança , Lactente , Streptococcus pneumoniae/genética , Infecções Pneumocócicas/prevenção & controle , Infecções Pneumocócicas/epidemiologia , Cobertura Vacinal , Vacinas Pneumocócicas , Sorogrupo , Vacinação , Nasofaringe , Portador Sadio/epidemiologia
11.
Zhongguo Dang Dai Er Ke Za Zhi ; 25(11): 1161-1169, 2023 Nov 15.
Artigo em Zh | MEDLINE | ID: mdl-37990462

RESUMO

OBJECTIVES: To explore the molecular characteristics of Staphylococcus aureus (S. aureus) in children, and to compare the molecular characteristics of different types of strains (infection and colonization strains) so as to reveal pathogenic molecular markers of S. aureus. METHODS: A cross-sectional study design was used to conduct nasopharyngeal swab sampling from healthy children in the community and clinical samples from infected children in the hospital. Whole genome sequencing was used to detect antibiotic resistance genes and virulence genes. A random forest method to used to screen pathogenic markers. RESULTS: A total of 512 S. aureus strains were detected, including 272 infection strains and 240 colonization strains. For virulence genes, the carrying rates of enterotoxin genes (seb and sep), extracellular enzyme coding genes (splA, splB, splE and edinC), leukocytotoxin genes (lukD, lukE, lukF-PV and lukS-PV) and epidermal exfoliating genes (eta and etb) in infection strains were higher than those in colonization strains. But the carrying rates of enterotoxin genes (sec, sec3, seg, seh, sei, sel, sem, sen, seo and seu) were lower in infection strains than in colonization strains (P<0.05). For antibiotic resistance genes, the carrying rates of lnuA, lnuG, aadD, tetK and dfrG were significantly higher in infection strains than in colonization strains (P<0.05). The accuracy of cross-validation of the random forest model for screening pathogenic markers of S. aureus before and after screening was 69% and 68%, respectively, and the area under the curve was 0.75 and 0.70, respectively. The random forest model finally screened out 16 pathogenic markers (sem, etb, splE, sep, ser, mecA, lnuA, sea, blaZ, cat(pC233), blaTEm-1A, aph(3')-III, ermB, ermA, ant(9)-Ia and ant(6)-Ia). The top five variables in the variable importance ranking were sem (OR=0.40), etb (OR=3.95), splE (OR=1.68), sep (OR=3.97), and ser (OR=1.68). CONCLUSIONS: The random forest model can screen out pathogenic markers of S. aureus and exhibits a superior predictive performance, providing genetic evidence for tracing highly pathogenic S. aureus and conducting precise targeted interventions.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Criança , Humanos , Staphylococcus aureus/genética , Estudos Transversais , Enterotoxinas/genética , Sequenciamento Completo do Genoma
12.
BMC Bioinformatics ; 23(1): 405, 2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36180820

RESUMO

BACKGROUND: Identifying protein complexes from protein-protein interaction network is one of significant tasks in the postgenome era. Protein complexes, none of which exceeds 10 in size play an irreplaceable role in life activities and are also a hotspot of scientific research, such as PSD-95, CD44, PKM2 and BRD4. And in MIPS, CYC2008, SGD, Aloy and TAP06 datasets, the proportion of small protein complexes is over 75%. But up to now, protein complex identification methods do not perform well in the field of small protein complexes. RESULTS: In this paper, we propose a novel method, called BOPS. It is a three-step procedure. Firstly, it calculates the balanced weights to replace the original weights. Secondly, it divides the graphs larger than MAXP until the original PPIN is divided into small PPINs. Thirdly, it enumerates the connected subset of each small PPINs, identifies potential protein complexes based on cohesion and removes those that are similar. CONCLUSIONS: In four yeast PPINs, experimental results have shown that BOPS has an improvement of about 5% compared with the SOTA model. In addition, we constructed a weighted Homo sapiens PPIN based on STRINGdb and BioGRID, and BOPS gets the best result in it. These results give new insights into the identification of small protein complexes, and the weighted Homo sapiens PPIN provides more data for related research.


Assuntos
Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas , Algoritmos , Proteínas de Ciclo Celular/metabolismo , Biologia Computacional/métodos , Humanos , Proteínas Nucleares/metabolismo , Mapeamento de Interação de Proteínas/métodos , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo
13.
J Pineal Res ; 73(4): e12832, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36073608

RESUMO

Circadian rhythm disorder is a significant risk factor for mental diseases, and the recovery of circadian rhythm function has gradually become a signal of effective antidepressant therapy. Sini powder (SNP) is a classical, traditional Chinese formula for depression treatment. However, few clinical reports have been recorded. This randomized, double-blinded, controlled trial (ChiCTR1900022700) aimed to explore the efficacy of SNP on depression via regulating circadian rhythm. In total, 36 patients with major depressive disorder (MDD) were enrolled for 4-weeks medication and 6-weeks follow-up. HAMD-24 score and circadian rhythm index, including dim light melatonin onset (DLMO) and phase angle difference (PAD), were included in the assessment. DLMO and PAD were statistically significant in the SNP group after 4 weeks of treatment (p < .05) and with greater improvement in DLMO (p = .03). In addition, DLMO and the HAMD-24 score showed a positive correlation (p < .05); the HAMD-24 score degree decreased significantly over time (p < .001). Similarly, interaction effects were shown significantly between group and time (p = .049). The duration of SNP supplementation was relatively short, and the sample size was relatively small. SNP granules combined with paroxetine tablets have definite efficacy in improving the circadian rhythms of MDD patients, reflecting the therapeutic advantages of traditional Chinese medicine as antidepressants.


Assuntos
Transtorno Depressivo Maior , Medicamentos de Ervas Chinesas , Melatonina , Humanos , Antidepressivos/uso terapêutico , Ritmo Circadiano/fisiologia , Transtorno Depressivo Maior/tratamento farmacológico , Melatonina/metabolismo , Paroxetina/uso terapêutico , Pós/uso terapêutico , Sono/fisiologia , Comprimidos/uso terapêutico , Medicamentos de Ervas Chinesas/uso terapêutico
14.
Inorg Chem ; 61(24): 9012-9018, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35658435

RESUMO

The pentazolate anion, cyclo-N5-, has received extensive attention as a new generation of energetic species for explosive or propulsion applications. Binary pentazolate compounds have been obtained under high-pressure conditions and their stability enhancement is crucial for obtaining more competitive high energy density materials (HEDMs). Here, we report the synthesis of a new solid phase of lithium pentazolate (space group P21/c) through the chemical transformation of pure lithium azide under high-pressure and high-temperature conditions. Upon decompression, the structural transition from P21/c-LiN5 to P21/m-LiN5 at ∼15.6 GPa was observed for the first time. Cyclo-N5- can be traced down to ∼5.7 GPa at room temperature and recovered to ambient pressure under a low-temperature condition (80 K). Our results reveal the enhancement of pentazolate anion stability with the increasing content of metal cations and demonstrate that low temperature is an effective route for the recovery of the pentazolate anion.

15.
Int J Colorectal Dis ; 37(8): 1739-1750, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35789424

RESUMO

PURPOSE: Anastomotic leakage (AL) is a common postoperative complication of rectal cancer, and transanal drainage tube (TDT) efficacy is still contentious. This study aimed to evaluate the TDT effect on AL prevention. METHODS: All relevant papers were searched by using a predefined search strategy (two randomized controlled trials (RCTs), one prospective study, and four retrospective studies). Meta-analysis was conducted to estimate AL and re-operation pooled rates. RESULTS: A total of 7 studies (1556 patients) were included: No significant statistic difference was found between two groups on AL rate (odds ratio (OR) 0.61, P = 0.11) and re-operation rate (OR 0.52, P = 0.10). For subgroup analysis, significant statistic difference was found between two groups on AL rate (OR 0.29, P = 0.002) and re-operation rate (OR 0.15, P = 0.04) in patients without neoadjuvant therapy. As for patients without diverting stoma, the AL rate (OR 0.35, P = 0.002) was significantly lower than that in patients without TDT. CONCLUSIONS: TDT may reduce AL morbidity and re-operation rate for patients without high risk of AL, but may be useless for those in high-risk situations.


Assuntos
Laparoscopia , Neoplasias Retais , Canal Anal/cirurgia , Anastomose Cirúrgica/efeitos adversos , Fístula Anastomótica/etiologia , Fístula Anastomótica/prevenção & controle , Fístula Anastomótica/cirurgia , Drenagem/efeitos adversos , Humanos , Laparoscopia/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Neoplasias Retais/complicações , Estudos Retrospectivos
16.
Phys Chem Chem Phys ; 24(9): 5738-5747, 2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35191433

RESUMO

Two stable high-pressure phases (C2/m-MnN4 and P1̄-MnN4) and four metastable phases (P4/mmm-MnN4, P1̄-MnN5, C2/m-MnN6 and P1̄-MnN8) are proposed by using ab initio evolutionary simulations. Besides the reported quasi-diatomic molecule N2, the armchair chain and S-like chain, the N4 ring and N22 ring are firstly reported in the P4/mmm-MnN4 and P1̄-MnN5 phases. A detailed study is performed on the energetic properties, mechanical properties and stability of these polynitrogen structures. Ab initio molecular dynamics simulations show that P1̄-MnN4 and P1̄-MnN5 can be quenched down to ambient conditions, and large decomposition energy barriers result in the high decomposition temperatures of P1̄-MnN4 (2000 K) and P1̄-MnN5 (3000 K). Interestingly, P4/mmm-MnN4 with the N4 ring exhibits outstanding mechanical properties, including high incompressibility, high hardness, uniform strength in the 2-D direction and excellent ductility. Strong N-N covalent bond and weak Mn-N ionic bond interactions are observed in the predicted Mn-N compounds, and the charge transfer between the Mn and N atoms provides an important contribution to the stabilization of polymeric N-structures. All the proposed structures are metallic phases. Our results provide a deep understanding of the chemistry of transition metal polynitrides under pressure and encourage experimental synthesis of these new manganese polynitrides in future.

17.
BMC Musculoskelet Disord ; 23(1): 584, 2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35715774

RESUMO

BACKGROUND: Osteoarthritis (OA) is a major cause of pain and disability worldwide. Despite the relatively high burden of the disease, the currently available non-surgical treatment options are directed towards symptomatic relief. Therefore, we propose the use of alendronate as a disease modifying agent to help slow and prevent OA. In addition, this study will utilize Whole-Organ Magnetic Resonance Imaging Score (WORMS) to evaluate the structural integrity of cartilage in the study population. High-quality evidence, limited to a few well-conducted randomized trials, highlights contradictory results on the effect of bisphosphonates on knee function and progression of OA. Therefore, a placebo-controlled, randomized trial is needed to evaluate the combined effect of alendronate and vit D on the structure of cartilage utilizing the WORMS score and its ability to treat knee pain in OA patients. METHODS: This multicenter, randomized, double-blinded, placebo-controlled study will evaluate the efficacy and safety of alendronate in early OA. Patients will undergo a 1:1 double-blinded randomization to receive a one-year course of either alendronate sodium vitamin D3 or placebo. The primary outcome is to compare WORMS score of knee joint at 6 and 12 months between both groups. Secondary endpoints will include WORMS score at 24 months, knee pain, radiographic progression of OA, severity of OA, quality of life, and serum inflammatory biomarkers at different assessment timepoints. To detect a 2.2% difference in cartilage loss between both groups with power of 80%, a sample size of 60 (30 per group) is proposed. DISCUSSION: This trial will give helpful and high-quality evidence regarding the potential therapeutic role of alendronate sodium vitamin D3, as compared to placebo, in the management of patients with knee OA regarding its role on cartilage loss, radiographic progression of OA, severity of OA, knee pain, quality of life, and inflammatory biomarkers. If proven effective, this intervention would be a great option for providing beneficial outcomes with a reduced cost in this patient population. TRIAL REGISTRATION: This trial was registered on clinicaltrials.gov (registration number: NCT04739592 ).


Assuntos
Alendronato , Osteoartrite do Joelho , Alendronato/farmacologia , Alendronato/uso terapêutico , Colecalciferol/uso terapêutico , Método Duplo-Cego , Humanos , Articulação do Joelho/patologia , Estudos Multicêntricos como Assunto , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/tratamento farmacológico , Dor , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Comprimidos/farmacologia , Comprimidos/uso terapêutico , Resultado do Tratamento , Vitamina D/uso terapêutico
18.
Int J Mol Sci ; 23(9)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35563347

RESUMO

Powdery mildew (PM), caused by the fungus Oidium lini in flax, can cause defoliation and reduce seed yield and quality. To date, one major dominant gene (Pm1) and three quantitative trait loci (QTL) on chromosomes 1, 7 and 9 have been reported for PM resistance. To fully dissect the genetic architecture of PM resistance and identify QTL, a diverse flax core collection of 372 accessions augmented with an additional 75 breeding lines were sequenced, and PM resistance was evaluated in the field for eight years (2010-2017) in Morden, Manitoba, Canada. Genome-wide association studies (GWAS) were performed using two single-locus and seven multi-locus statistical models with 247,160 single nucleotide polymorphisms (SNPs) and the phenotypes of the 447 individuals for each year separately as well as the means over years. A total of 349 quantitative trait nucleotides (QTNs) were identified, of which 44 large-effect QTNs (R2 = 10-30%) were highly stable over years. The total number of favourable alleles per accession was significantly correlated with PM resistance (r = 0.74), and genomic selection (GS) models using all identified QTNs generated significantly higher predictive ability (r = 0.93) than those constructed using the 247,160 genome-wide random SNP (r = 0.69), validating the overall reliability of the QTNs and showing the additivity of PM resistance in flax. The QTNs were clustered on the distal ends of all 15 chromosomes, especially on chromosome 5 (0.4-5.6 Mb and 9.4-16.9 Mb) and 13 (4.7-5.2 Mb). To identify candidate genes, a dataset of 3230 SNPs located in resistance gene analogues (RGAs) was used as input for GWAS, from which an additional 39 RGA-specific QTNs were identified. Overall, 269 QTN loci harboured 445 RGAs within the 200 Kb regions spanning the QTNs, including 45 QTNs located within the RGAs. These RGAs supported by significant QTN/SNP allele effects were mostly nucleotide binding site and leucine-rich repeat receptors (NLRs) belonging to either coiled-coil (CC) NLR (CNL) or toll interleukin-1 (TIR) NLR (TNL), receptor-like kinase (RLK), receptor-like protein kinase (RLP), transmembrane-coiled-coil (TM-CC), WRKY, and mildew locus O (MLO) genes. These results constitute an important genomic tool for resistance breeding and gene cloning for PM in flax.


Assuntos
Linho , Resistência à Doença/genética , Erysiphe , Linho/genética , Genes de Plantas , Estudo de Associação Genômica Ampla/métodos , Genômica , Melhoramento Vegetal/métodos , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Reprodutibilidade dos Testes
19.
Fa Yi Xue Za Zhi ; 38(5): 579-583, 2022 Oct 25.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-36727172

RESUMO

OBJECTIVES: To study the cooling reaction kinetic characteristics of the temperature difference between cadaver temperature and ambient temperature (hereinafter referred to as "cadaver temperature difference") according to the reaction kinetics method. METHODS: Thirty rabbits were randomly divided into 5 groups with 6 rabbits in each group. The rabbits were injected with 10% potassium chloride solution intravenously. After death, the rabbits were placed at 5 ℃, 10 ℃, 15 ℃, 20 ℃ and 25 ℃ environment condition, respectively, and the rectal temperature was measured every minute for 20 hours. The measured cadaver temperature was subtracted from ambient temperature, and the cadaver temperature difference data was calculated using the reaction kinetics formula. The linear regression equation was fitted for analysis, and the experimental results were applied to the temperature difference data of human body after death for verification. RESULTS: Under different environmental conditions, the linear coefficient determination of temperature difference -ln(C/C0) in rabbits was 0.99, showing a good linear relationship with time t. The application of human body temperature data after death was consistent with the results of animal experiments. CONCLUSIONS: Under stable conditions, the temperature difference cooling process after death in rabbits is a first-order kinetic response. The method can also be used to study the temperature difference in human body after death.


Assuntos
Temperatura Corporal , Animais , Humanos , Coelhos , Temperatura , Cinética , Cadáver
20.
Zhongguo Dang Dai Er Ke Za Zhi ; 24(8): 874-880, 2022 Aug 15.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-36036125

RESUMO

OBJECTIVES: To investigate the carriage status of Streptococcus pneumoniae (S.pneumoniae) and Moraxella catarrhalis (M. catarrhalis) in preschool children and the influencing factors for the carriage status. METHODS: The stratified cluster sampling method was used to select 2 031 healthy children from seven kindergartens in Shunde District of Foshan in Guangdong, China. Nasal swabs were collected from all children for the isolation and identification of S. pneumoniae and M. catarrhalis. The carriage status of S. pneumoniae and M. catarrhalis was analyzed in terms of its association with demographic features and hospital- and community-related factors. RESULTS: The carriage rates of S. pneumoniae and M. catarrhalis were 21.81% and 52.44%, respectively among the children. The co-carriage rate of S. pneumoniae and M. catarrhalis was 14.87%. The correspondence analysis showed that the factors such as lower grade, non-local registered residence, living in rural areas, small living area, history of respiratory tract infection but no history of antibiotic use, allergic skin diseases, and no hospital-related exposure history were significantly associated with the co-carriage of S. pneumoniae and M. catarrhalis among the children (P<0.05). CONCLUSIONS: Co-carriage of S. pneumoniae and M. catarrhalis can be observed in preschool children. Young age, poor living environment, a history of respiratory tract infection but no history of antibiotic use, allergic skin diseases, and no hospital-related exposure history are important risk factors for the co-carriage of S. pneumoniae and M. catarrhalis in preschool children.


Assuntos
Infecções Respiratórias , Dermatopatias , Antibacterianos , Portador Sadio , Pré-Escolar , Haemophilus influenzae , Humanos , Lactente , Moraxella catarrhalis , Nasofaringe , Streptococcus pneumoniae
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA