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1.
J Craniofac Surg ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38710039

RESUMO

Closed treatment of mandibular condylar fractures has been used for its indications based on the fracture site, fracture status, and patient age. Posttreatment mandibular condyle size is associated with mandibular function; however, a few studies have reported bone remodeling patterns and volume changes in the condyle and glenoid fossa after mandibular condylar head fractures (CHFs). Therefore, volumetric changes in the mandibular condyle and glenoid fossa were analyzed in the present study, and bone remodeling patterns were evaluated after mandibular CHFs. The present study included 16 condyles from 12 patients who received closed treatment for CHF. After reconstruction of a 3-dimensional skull model, including the mandible, using computed tomography data taken immediately after injury and 6 months after treatment, volume changes in the mandibular condyle and glenoid fossa were analyzed. The condylar volume increased by 0.32±0.66 cm3 during the 6-month healing period without statistical significance (P=0.093). Regarding the glenoid fossa, the fossa showed a statistically significant volume increase of 0.41±0.59 cm3 (P=0.021), and 12 glenoid fossae (75%) showed downward bone apposition; however, no change or only mild bone resorption was observed in 4 glenoid fossae (25%). The results of this study indicated that the volume changes in the mandibular condyle after closed treatment of a mandibular CHF are not significant, and the glenoid fossa adapts to the displaced mandibular condyle through downward growth accompanied by volume increase.

2.
J Am Chem Soc ; 146(14): 9506-9511, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38557065

RESUMO

Clusters showing a giant magnetocaloric effect (MCE) are of interest as molecular coolants for magnetic refrigeration. Herein, we report two heterometallic clusters, denoted as Gd152Ni14@Cl24 and Sm152Ni8, just to highlight their inorganic core motifs, obtained by ligand-controlled co-hydrolysis of Ni2+ and Ln3+ (Ln = Gd, Sm) in the presence of N-(2-hydroxyethyl)iminodiacetic acid (H2HEIDA). Both clusters display fascinating cubic Tinkertoy-like structures, with the core motifs being built of multiple metallic shells of Platonic and Archimedean polyhedra. The isothermal magnetic entropy change─a direct measurement of MCE─was determined to be 52.65 J·kg-1·K-1 at 2.5 K and 7.0 T for the Gd-containing cluster; this value is the highest known for any molecular clusters so far reported.

3.
Dalton Trans ; 53(13): 5779-5783, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38482700

RESUMO

Herein the synthesis, structural characterization, and magnetic properties of a Pr(IV) complex [Pr(OSiPh3)4(L)] (1, L = 4,4'-dimethoxy-2,2'-bipyridine) are reported. The stability of the Pr(IV) complex significantly enhanced with the use of the bidentate ligand L. Slow magnetic relaxation was observed at low temperatures, indicating that the complex may be the first single-ion magnet with a tetravalent lanthanide ion being the magnetic center.

4.
Sci Rep ; 14(1): 74, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38168759

RESUMO

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxin that can cause gastrointestinal ulcers by affecting dopamine levels. Therefore, MPTP has been considered a toxic substance that causes gastric ulcer disease in experimental animals. In this study, tree shrews were used as the animal model of gastric mucosa injury, and MPTP was intraperitoneally injected at a lower MPTP dosage 2 mg/kg/day for 13 weeks, while tree shrews were not injected as the control group. Under the light microscope, local congestion or diffuse bleeding points of gastric mucosa and multiple redness and swelling bleeding symptoms on the inner wall were observed in the treatment group, as well as immune cell infiltration was found in HE staining, but no such phenomenon was observed in the control group. In order to explore the molecular basis of changes in MPTP induced gastric mucosa injury, the transcriptome and proteome data of gastric mucosa were analyzed. We observed significant differences in mRNA and protein expression levels under the influence of MPTP. The changes in mRNA and proteins are related to increased immune infiltration, cellular processes and angiogenesis. More differentially expressed genes play a role in immune function, especially the candidate genes RPL4 and ANXA1 with significant signal and core role. There are also differentially expressed genes that play a role in mucosal injury and shedding, especially candidate genes GAST and DDC with certain signaling and corresponding functions. Understanding the factors and molecular basis that affect the expression of related genes is crucial for coping with Emotionality gastric mucosa injury disease and developing new treatment methods to establish the ability to resist disease.


Assuntos
Tupaia , Tupaiidae , Animais , Tupaia/genética , Musaranhos/genética , Proteômica , Análise de Sequência de RNA , RNA Mensageiro , China , Estômago
5.
Nanoscale ; 16(6): 3061-3070, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38240625

RESUMO

Physical reservoirs employed to map time-series data and analyze extracted features have attracted interest owing to their low training cost and mitigated interconnection complexity. This study reports a physical reservoir based on a bilayer oxide-based dynamic memristor. The proposed device exhibits a nonlinear current response and short-term memory (STM), satisfying the requirements of reservoir computing (RC). These characteristics are validated using a compact model to account for resistive switching (RS) via the dynamic evolution of the internal state variable and the relocation of oxygen vacancies. Mathematically, the transient current response can be quantitatively described according to a simple set of equations to correlate the theoretical framework with experimental results. Furthermore, the device shows significant reliability and ability to distinguish 4-bit inputs and four diverse neural firing patterns. Therefore, this work shows the feasibility of implementing physical reservoirs in hardware and advances the understanding of the dynamic response.

6.
Inorg Chem ; 63(21): 9511-9519, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38135507

RESUMO

Lanthanide complexes with judiciously designed ligands have been extensively studied for their potential applications as single-molecule magnets. With the influence of ligands on their magnetic properties generally established, recent research has unearthed certain effects inherent to site differentiation due to the different types and varying numbers of substituents on the same ligand platform. Using two new sandwich-type Er(III) complexes with cyclooctatetraenyl (COT) ligands featuring two differently positioned trimethylsilyl (TMS) substituents, namely, [Li(DME)Er(COT1,5-TMS2)2]n (Er1) and [Na(DME)3][Er(COT1,3-TMS2)2] (Er2) [COT1,3-TMS2 and COT1,5-TMS2 donate 1,3- and 1,5-bis(trimethylsilyl)-substituted cyclooctatetraenyl ligands, respectively; DME = 1,2-dimethoxyethane], and with reference to previously reported [Li(DME)3][Er(COT1,4-TMS2)2] (A) and [K(DME)2][Er(COT1,4-TMS2)2] (B), any possible substituent position effects have been explored for the first time. The rearrangement of the TMS substituents from the starting COT1,4-TMS2 to COT1,3-TMS2 and COT1,5-TMS2, by way of formal migration of the TMS group, was thermally induced in the case of Er1, while for the formation of Er2, the use of Na+ in the placement of its Li+ and K+ congeners is essential. Both Er1 and Er2 display single-molecule magnetic behaviors with energy barriers of 170(3) and 172(6) K, respectively. Magnetic hysteresis loops, butterfly-shaped for Er1 and wide open for Er2, were observed up to 12 K for Er1 and 13 K for Er2. Studies of magnetic dynamics reveal the different pathways for relaxation of magnetization below 10 K, mainly by the Raman process for Er1 and by quantum tunneling of magnetization for Er2, leading to the order of magnitude difference in magnetic relaxation times and sharply different magnetic hysteresis loops.

7.
Int Immunopharmacol ; 125(Pt A): 111098, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37925946

RESUMO

BACKGROUND: The efficacy and safety of tyrosine kinase inhibitors (TKIs) combined with anti-PD-1 antibodies (α-PD-1) in advanced hepatocellular carcinoma (HCC) with high hepatitis B virus (HBV) DNA levels (>500 IU/mL) remain unclear. METHODS: We retrospectively assessed patients from seven medical institutions diagnosed with HBV-related HCC, undergoing treatment with TKIs and α-PD-1 in conjunction with antiviral therapies. Based on HBV-DNA levels, patients were categorized into either high (HHBV-DNA, >500 IU/mL) or low HBV-DNA (LHBV-DNA, ≤500 IU/mL) cohorts Propensity score matching (PSM) was used to minimize baseline imbalance between groups. RESULTS: 149 patients were included, with 66 patients exhibiting HBV-DNA > 500 IU/mL and 83 patients presenting HBV-DNA ≤ 500 IU/mL. Compared with the LHBV-DNA cohort, the HHBV-DNA cohort had a greater incidence of serum HBeAg positivity, tumor diameter ≥ 10 cm, and vascular invasion. Following PSM, 57 individuals were enrolled in each group. Oncological outcomes were comparable between HHBV-DNA and LHBV-DNA cohorts before and after PSM. Before PSM, the median PFS and OS were 6.1 months and 17.5 months in the HHBV-DNA cohort and 6.7 months and 19.3 months in the LHBV-DNA cohort (all P > 0.05). After PSM, the median PFS and OS were 6.0 months and 19.5 months in the HHBV-DNA cohort and 6.0 months and 17.1 months in the LHBV-DNA cohort, respectively (all P > 0.05). Safety profiles were equivalent across cohorts with no fatal incidents reported. Seven patients (4.7 %) had HBV reactivation. 1 (0.7 %) from HHBV-DNA and 6 (4.0 %) from LHBV-DNA (P = 0.134). Only one patient developed HBV-related hepatitis. CONCLUSIONS: The effectiveness and safety of TKIs plus α-PD-1 in advanced HCC with HBV-DNA > 500 IU/mL were not compromised in the context of concomitant antiviral therapy.


Assuntos
Carcinoma Hepatocelular , Hepatite B Crônica , Hepatite B , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Vírus da Hepatite B/fisiologia , Neoplasias Hepáticas/patologia , DNA Viral , Estudos Retrospectivos , Receptor de Morte Celular Programada 1 , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/complicações , Antivirais/efeitos adversos , Hepatite B/tratamento farmacológico
8.
Protein Pept Lett ; 30(11): 930-940, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37870056

RESUMO

BACKGROUND: Increasingly convincing evidence has revealed that circular RNAs (circRNAs) are critical regulatory components of hepatocellular carcinoma (HCC) genesis. However, the expression of circRNAs in HCC and the relevance of circRNAs to HCC progression remain largely unexplained. METHODS: qRT-PCR or western blotting was utilized to confirm circ_0001687, miR-140-3p, and Forkhead Box q1 (FOXQ1) levels in HCC tissues or cells. Cell proliferation ability was evaluated via CCK-8 and colony formation assay. The correlation of circ_0001687 or FOXQ1 and miR-140- 3p was determined using dual luciferase reporter assay. Nude mice xenograft tumor model was constructed to verify the effect of circ_0001687 on tumor growth. RESULTS: Circ_0001687 was elevated in HCC. Function assays and the nude mice xenograft tumor model indicated that circ_0001687 acts as a promoting gene in HCC to regulate the proliferation of the tumor cell and foster tumor growth. Further mechanistic exploration revealed that the tumor growth-promoting mechanism of circ_0001687 relied on blocking the inhibitory effect of miR-140- 3p on FOXQ1 and activating FOXQ1 expression. CONCLUSION: This research indicated the role of circ_0001687/miR-140-3p/FOXQ1 network in regulating HCC development. These may provide new insights into the treatment of HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Animais , Camundongos , Humanos , Carcinoma Hepatocelular/genética , RNA Endógeno Competitivo , Camundongos Nus , RNA Circular/genética , Neoplasias Hepáticas/genética , Proliferação de Células , Modelos Animais de Doenças , MicroRNAs/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Fatores de Transcrição Forkhead/genética
9.
Materials (Basel) ; 16(17)2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37687683

RESUMO

Plasmonic absorbers with broadband angle-insensitive antireflection have attracted intense interests because of its wide applications in optical devices. Hybrid surfaces with multiple different sub-wavelength array units can provide broadened antireflection, while many of these antireflective surfaces only work for specific angles and require high complexity of nanofabrication. Here, a plasmonic asymmetric nanostructure composed of the moth-eye dielectric nanoarray partially modified with the top Ag nanoshell providing a side opening for broadband incident-angle-insensitive antireflection and absorption, is rationally designed by nanoimprinting lithography and oblique angle deposition. This study illustrates that the plasmonic asymmetric nanostructure not only excites strong plasmonic resonance, but also induces more light entry into the dielectric nanocavity and then enhances the internal scattering, leading to optimized light localization. Hence, the asymmetric nanostructure can effectively enhance light confinement at different incident angles and exhibit better antireflection and the corresponding absorption performance than that of symmetric nanostructure over the visible wavelengths, especially suppressing at least 16.4% lower reflectance in the range of 645-800 nm at normal incidence.Moreover, the reflectance variance of asymmetric nanostructure with the incident angle changing from 5° to 60° is much smaller than that of symmetric nanostructure, making our approach relevant for various applications in photocatalysis, photothermal conversion, and so on.

10.
Cell Rep ; 42(7): 112766, 2023 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-37421618

RESUMO

Neuraminidase is suggested as an important component for developing a universal influenza vaccine. Targeted induction of neuraminidase-specific broadly protective antibodies by vaccinations is challenging. To overcome this, we rationally select the highly conserved peptides from the consensus amino acid sequence of the globular head domains of neuraminidase. Inspired by the B cell receptor evolution process, a reliable sequential immunization regimen is designed to result in immuno-focusing by steering bulk immune responses to a selected region where broadly protective B lymphocyte epitopes reside. After priming neuraminidase protein-specific antibody responses in C57BL/6 or BALB/c inbred mice strains by immunization or pre-infection, boost immunizations with certain neuraminidase-derived peptide-keyhole limpet hemocyanin conjugates significantly strengthened serum neuraminidase inhibition activities and cross-protections. Overall, this study provides proof of concept for a peptide-based sequential immunization strategy for achieving targeted induction of cross-protective antibody response, which provides references for designing universal vaccines against other highly variable pathogens.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Virus da Influenza A Subtipo H5N1 , Vacinas contra Influenza , Influenza Humana , Infecções por Orthomyxoviridae , Animais , Camundongos , Humanos , Infecções por Orthomyxoviridae/prevenção & controle , Neuraminidase , Anticorpos Antivirais , Camundongos Endogâmicos C57BL , Vacinação , Peptídeos , Camundongos Endogâmicos BALB C , Glicoproteínas de Hemaglutininação de Vírus da Influenza
11.
Inorg Chem ; 62(21): 8435-8441, 2023 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-37171409

RESUMO

Gadolinium is a special case in spectroscopy because of the near isotropic nature of the 4f7 configuration of the +3 oxidation state. Gd3+ complexes have been studied in several symmetries to understand the underlying mechanisms of the ground state splitting. The abundance of information in Gd3+ spectra can be used as a probe for properties of the other rare earth ions in the same complexes. In this work, the zero-field splitting (ZFS) of a series of Gd3+ pentagonal bipyramidal complexes of the form [GdX1X2(Leq)5]n+ [n = 1, X = axial ligands: Cl-, -OtBu, -OArF5 or n = 3, X = tBuPO(NHiPr)2, Leq = equatorial ligand: Py, THF or H2O] with near fivefold symmetry axes along X1-Gd-X2 was investigated. The ZFS parameters were determined by fitting of room-temperature continuous wave electron paramagnetic resonance (EPR) spectra (at X-, K-, and Q-band) to a spin Hamiltonian incorporating extended Stevens operators compatible with C5 symmetry. Examination of the acquired parameters led to the conclusion that the ZFS is dominated by the B20 term and that the magnitude of B20 is almost entirely dependent on, and inversely proportional to, the donor strength of the axial ligands. Surveying the continuous shape measure and the X1-Gd-X2 angle of the complexes showed that there is some correlation between the proximity of each complex to D5h symmetry and the magnitude of the B65 parameter, but that the deformation of the X1-Gd-X2 angle is more significant than other distortions. Finally, the magnitude of B20 was found to be inversely proportional to the thermal barrier for the reversal of the magnetic moment (Ueff) of the corresponding isostructural Dy3+ complexes.

12.
Ying Yong Sheng Tai Xue Bao ; 34(4): 892-902, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37078306

RESUMO

To investigate the effects of biocrusts development on aggregate stability and splash erosion of Mollisols and to understand its function in soil and water conservation, we collected biocrusts (cyano crust and moss crust) samples in croplands during the growing season and measured the differences in aggregate stability between biocrusts and uncrusted soil. The effects of biocrusts on reduction of raindrop kinetic energy were determined and splash erosion amounts were obtained with single raindrop and simulated rainfall experiments. The correlations among soil aggregate stability, splash erosion characteristics, and fundamental properties of biocrusts were analyzed. The results showed that compared to uncrusted soil, the cyano crust and the moss crust decreased the proportion of soil water-stable aggregates <0.25 mm by 10.5% and 21.8%, respectively, while their soil water-stable aggregates 5-10 mm were 4.0 and 8.8 times as that of uncrusted soil. In contrast to uncrusted soil, the macroaggregate content (R0.25), mean weight diameter (MWD), and geometric mean diameter (GMD) of biocrusts were 31.5%, 76.2%, and 33.5% higher, respectively. In addition, biocrusts reduced raindrop kinetic energy by an average of 0.48 J compared to uncrusted soil. The breakthrough raindrop kinetic energy of cyano crust and moss crust were 2.9 and 26.2 times as that of uncrusted soil, while the reduction of raindrop kinetic energy by cyano crust with high biomass was 1.3 and 6.6 times as that of medium and low biomass, respectively. Under the single raindrop and simulated rainfall conditions, biocrusts reduced splash erosion amounts by 47.5% and 79.4%, respectively. The proportion of aggregates >0.25 mm in the splash soil particles of biocrusts (37.9%) was 40.3% lower than that of uncrusted soil, while the proportion of aggregates >0.25 mm decreased as biocrust biomass increased. Moreover, the aggregate stability, splash erosion amount, and fundamental properties of biocrusts were significantly correlated. The MWD of aggregates was significantly and negatively correlated with the splash erosion amount under single raindrop and simulated rainfall conditions, indicating that the improved aggregate stability of surface soil caused by biocrusts accounted for reducing splash erosion. The biomass, thickness, water content, and organic matter content of biocrusts had significant effects on aggregate stability and splash characteristics. In conclusion, biocrusts significantly promoted soil aggregate stability and reduced splash erosion, which had great significance to soil erosion prevention and the conservation and sustainable utilization of Mollisols.


Assuntos
Briófitas , Cianobactérias , Ecossistema , Microbiologia do Solo , Solo , China , Água , Produtos Agrícolas
13.
Chemistry ; 29(29): e202300256, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-36863997

RESUMO

Two dichloride-bridged dinuclear dysprosium(III) complexes based on salen ligands, namely, [Dy(L1 )(µ-Cl)(thf)]2 (1; H2 L1 =N,N'-bis(3,5-di-tert-butylsalicylidene)phenylenediamine) and [Dy2 (L2 )2 (µ-Cl)2 (thf)2 ]2 (2; H2 L2 =N,N'-bis(3,5-di-tert-butylsalicylidene)ethylenediamine) are reported. These two complexes have two short Dy-O(PhO) bonds that exhibit angles of ∼90° for 1 and ∼143° for 2, leading to clear slow relaxation of the magnetization for 2 and not for 1. Compound 2 has a near-identical core to the recently reported compound [Dy2 (L3 )2 (µ-Cl)2 (thf)2 ] (3; H2 L3 =N-(2-pyridylmethyl)-N,N-bis(2'-hydroxy-3',5'-di-tert-butylbenzyl)amine). The only substantial difference is the relative angle of the two O(PhO) -Dy-O(PhO) vectors, which is collinear in 2 owing to inversion symmetry and ∼68° in 3 due to a molecular C2 axis. It is shown that this subtle structural difference leads to large differences in the dipolar ground states, giving rise to open magnetic hysteresis for 3 and not for 2.

14.
Enzyme Microb Technol ; 166: 110225, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36921551

RESUMO

L-Phosphinothricin (L-PPT) is the effective constituent in racemic PPT (a high-efficiency and broad-spectrum herbicide), and the exploitation of green and sustainable synthesis route for L-PPT has always been the focus in pesticide industry. In recent years, "one-pot, two-step" enzyme-mediated cascade strategy is a mainstream pathway to obtain L-PPT. Herein, RgDAAO and BsLeuDH were applied to expand "one-pot, two-step" process. Notably, a NADH-dependent leucine dehydrogenase from Bacillus subtilis (BsLeuDH) was firstly characterized and attempted to generate L-PPT, achieving an excellent enantioselectivity (99.9% ee). Meanwhile, a formate dehydrogenase from Pichia pastoris (PpFDH) was utilized to implement NADH cofactor regeneration and only CO2 was by-product. Sufficient amount of the corresponding keto acid precursor PPO was obtained by oxidation of D-PPT relying on a D-amino acid oxidase from Rhodotorula gracilis (RgDAAO) with content conversion (46.1%). L-PPT was ultimately prepared from racemized PPT via oxidative deamination catalyzed by RgDAAO and reductive amination catalyzed by BsLeuDH, achieving 80.3% overall yield and > 99.9% ee value.


Assuntos
NADH Desidrogenase , NAD , Leucina Desidrogenase/genética , Leucina Desidrogenase/metabolismo , NAD/metabolismo , Leucina , NADH Desidrogenase/metabolismo
15.
Drug Deliv Transl Res ; 13(3): 782-794, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36114310

RESUMO

Circular RNAs (circRNAs) are a class of highly stable and closed-loop noncoding RNA that are involved in the occurrence and development of hepatocellular carcinoma (HCC). However, little is known about the therapeutic role of circRNAs in HCC. We found that high circ_0058051 expression was negatively correlated with the prognosis of HCC patients. Circ_0058051 knockdown attenuated the proliferation and colony formation, meanwhile inhibited migration of HCC cells. Circ_0058051 may be used as a target for HCC gene therapy. We synthesized a novel small interfering RNA (siRNA) delivery system, PEG-PCL-PEI-C14-SPIONs (PPPCSs), based on superparamagnetic iron oxide nanoparticles (SPIONs). PPPCSs protected the siRNA of circ_0058051 from degradation in serum and effectively delivered siRNA into SMMC-7721 cells. Meanwhile, intravenous injection of the PPPCSs/siRNA complex could inhibit tumor growth in the subcutaneous tumor model. In addition, the nanocomposite is not toxic to the organs of nude mice. The above results show that PPPCSs/si-circ_0058051 complex may provide a novel and promising method of HCC treatment.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Animais , Camundongos , Carcinoma Hepatocelular/genética , RNA Circular/genética , RNA Circular/metabolismo , Neoplasias Hepáticas/genética , MicroRNAs/genética , Camundongos Nus , RNA Interferente Pequeno/genética , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral
16.
Ying Yong Sheng Tai Xue Bao ; 33(7): 1773-1782, 2022 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-36052779

RESUMO

We selected typical croplands in the black soil region of Northeast China to analyze the characteristics of biocrusts during the growing season, including species composition, thickness, coverage, and biomass (chlorophyll content). We collected bareground soil and biocrusts samples with chlorophyll content of 5-15, 15-25, 25-35, and 35-50 mg·g-1, and measured the soil disintegration rate and soil maximum disintegration ratio of each sample using a force gauge in the laboratory. The results showed that: 1) biocrusts dominated by algae and moss were frequently developed in the croplands, with Stigeoclonium and Bryum capillare as the most common species, respectively. The thickness and biomass of algal crusts were significantly lower than moss crusts, with a successional trend from algal crusts to moss crusts. 2) The coverage, thickness, and biomass of biocrusts in croplands were negatively correlated with the frequency and intensity of tillage disturbance. For instance, the values of those characterisitics were only 27.8%, 1.52 mm, and 6.49 mg·g-1 on average, respectively, in traditional tillage croplands, and increased to 83.5%, 2.74 mm, and 34.16 mg·g-1, respectively, in the croplands with conservational tillage. 3) Biocrusts considerably reduced the disintegration of surface soil, particularly in the layer of biocrusts. Compared to the bareground soil, the soil disintegration rate of biocrusts, with four levels of biomass (with chlorophyll content of 5-15, 15-25, 25-35, and 35-50 mg·g-1), was reduced by 43.1%, 50.1%, 55.5%, and 59.8%, respectively, while the soil maximum disintegration ratios were reduced by 11.4%, 17.7%, 33.2%, and 36.6%, respectively. 4) Soil disintegration rate and maximum disintegration ratio were significantly and negatively correlated with the biomass and thickness of biocrusts, indicating that the impacts of biocrusts on soil disintegration were primarily caused by the improvements in physical properties of surface soil. In conclusion, biocrusts were frequently deve-loped in croplands in the black soil region of Northeast China, owing to less disturbance following the conversion from traditional tillage to conservational tillage. They had the potential to protect surface soil against disintegration and improve soil anti-scourability, which was critical for soil conservation in croplands in this region.


Assuntos
Briófitas , Solo , Biomassa , China , Clorofila , Produtos Agrícolas , Microbiologia do Solo
17.
Inorg Chem ; 61(33): 13096-13103, 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-35946578

RESUMO

We report on the remarkable stability of unprecedented, monomeric lead(II) hydrides M+[LPb(II)H]- (M[1-H]), where L = 2,6-bis(3,5-diphenylpyrrolyl)pyridine and M = (18-crown-6)potassium or ([2.2.2]-cryptand)potassium. The half-life of [K18c6][1-H] of ∼2 days in tetrahydrofuran at 25 °C is significantly longer than those reported for dimeric lead(II) hydrides supported by bulky terphenyl ligands (few hours at low temperatures), which are the only examples known for lead(II) hydride compounds. The presence of a Pb-H bond in [1-H]- was unambiguously identified by multinuclear NMR spectroscopy. Remarkably, a 1H resonance of the hydride ligand was found at δ = 41.43 ppm (1JPbH = 1312 Hz). For reactivity study, [1-H]- serves as an excellent hydroboration catalyst with high turnover numbers and turnover frequencies for several carbonyl compounds.

18.
Front Bioeng Biotechnol ; 10: 929784, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35845398

RESUMO

Biocatalyzed asymmetric reduction of ketones is an environmentally friendly approach and one of the most cost-effective routes for producing chiral alcohols. In comparison with the well-studied reduction of prochiral ketones to generate chiral alcohols with one chiral center, resolution of racemates by ketoreductases (KREDs) to produce chiral compounds with at least two chiral centers is also an important strategy in asymmetric synthesis. The development of protein engineering and the combination with chemo-catalysts further enhanced the application of KREDs in the efficient production of chiral alcohols with high stereoselectivity. This review discusses the advances in the research area of KRED catalyzed asymmetric synthesis for biomanufacturing of chiral chemicals with at least two chiral centers through the kinetic resolution (KR) approach and the dynamic kinetic resolution (DKR) approach.

19.
Zhongguo Zhong Yao Za Zhi ; 47(8): 2008-2014, 2022 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-35531715

RESUMO

Chinese medicine dispensing granules, the result of the efforts to transform Chinese medicinal decoction pieces in China, features portability and ease of storage. Thus, it is destined to be an indispensible dosage form in the modernization drive of Chinese medicine. The Announcement on Ending the Pilot Project of Chinese Medicine Dispensing Granules was released in February 2021 and relevant regulations went into force in November 2021, which marks the a new journey for the development of Chinese medicine dispensing granules and the beginning of the "post-pilot era". However, it faces the challenges in quality and standard. This study reviewed the history of Chinese medicine dispensing granules, analyzed the technical progress, market, and main problems in development, and proposed suggestions and prospects for its development in the "post-pilot era", which is expected to serve as a reference for its industry development and rational use.


Assuntos
Medicamentos de Ervas Chinesas , Medicina Tradicional Chinesa , China , Medicamentos de Ervas Chinesas/uso terapêutico , Desenvolvimento Industrial , Projetos Piloto
20.
Angew Chem Int Ed Engl ; 61(26): e202206022, 2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35543224

RESUMO

The fast Raman relaxation process via a virtual energy level has become a puzzle for how to chemically engineer single-molecule magnets (SMMs) with better performance. Here, we use the trifluoromethyl group to systematically substitute the methyl groups in the axial position of the parent bis-butoxide pentapyridyl dysprosium(III) SMM. The resulting complexes-[Dy(OLA )2 py5 ][BPh4 ] (LA =CH(CF3 )2 - 1, CH2 CF3 - 2, CMe2 CF3 - 3)-show progressively enhanced TB hys (@100 Oe s-1 ) from 17 K (for 3), 20 K (for 2) to 23 K (for 1). By experimentally identifying the varied under barrier relaxation energy in the 5-500 cm-1 regime, we are able to identify that the C-F bond related vibration energy of the axial ligand ranging from 200 to 350 cm-1 is the key variant for this improvement. Thus, this finding not only reveals a correlation between the structure and the Raman process but also provides a paradigm for how to apply the vibronic barrier model to analyze multi-phonon relaxation processes in lanthanide SMMs.

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