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3.
Int J Mol Sci ; 21(8)2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32316588

RESUMO

The present work investigated the anti-inflammatory, antioxidant, and lung protection effects of acetylated Pleurotus geesteranus polysaccharides (AcPPS) on acute lung injury (ALI) mice. The acetylation of AcPPS was successfully shown by the peaks of 1737 cm-1 and 1249 cm-1 by FTIR. The animal experiments demonstrated that lung damage can be induced by zymosan. However, the supplementation of AcPPS had potential effects on reducing lung index, remitting inflammatory symptoms (TNF-α, IL-1ß, and IL-6), inhibiting NF-κB signal pathway based on up-regulating the level of IκBα and down-regulating p-IκBα level by Western blotting and immunofluorescence assay, preventing oxidative stress (ROS, SOD, GSH-Px, CAT, T-AOC, and MDA), reducing lipid accumulation (TC, TG, LDL-C, HDL-C, and VLDL-C), and alleviating lung functions by histopathologic observation. These results demonstrated that AcPPS might be suitable for natural food for prevention or remission in ALI.

4.
Zhongguo Zhen Jiu ; 40(3): 273-6, 2020 Mar 12.
Artigo em Chinês | MEDLINE | ID: mdl-32270640

RESUMO

Based on the analysis of the present situation of standardization of moxibustion, it is found that the published standards of acupuncture and moxibustion are predominated at acupoint standard and acupuncture manipulation standard. Moxibusiton standardization mainly focuses on the manipulation. It is relatively lack of the standards of moxibustion materials and device. Four suggestions are put forward on the development strategies of moxibustion standardization: 1. Rectify the current situation that more attention paid to acupuncture rather than moxibustion, strengthen the inheritance of traditional experiences and the excavation of ancient literature, expand the indications of moxibustion and confirm the clinical effect of it. 2. Promote the whole process of moxibustion standardization, starting from moxibustion technique to its material, device and manipulation. 3. Enhance the equipment construction of moxibustion, combine with other build engineering disciplines, e.g. artificial intelligence and communication technology, and construct a multi-disciplinary intersection system. 4. Improve the promotion and development mode of moxibustion, propel all-round development of moxibustion in the clinical application, promotion mode and standardization construction, etc.

5.
J Food Biochem ; 44(5): e13187, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32185800

RESUMO

The anti-inflammatory and anti-asthmatic effects of rubusoside (Rbs) were investigated in the ovalbumin (OVA)-induced asthmatic mice, followed by effective attenuation of Rbs treatment on the airway hyperresponsiveness and reduction of inflammatory cells inside the bronchoalveolar lavage fluid (BALF). The mitigation of inflammatory infiltration as a result of Rbs treatment was histologically observed in these mice lungs. Rbs contributed to the decrease of inflammatory cytokines (TNF-α, IL-13, IL-6, IL-5, and IL-4) inside the BALF of mice with asthma. A decline of OVA-dependent IgE and IgG1 inside the serum was also noticed in these mice. Rbs was proved to enhance the mRNA level of Foxp3 inside the mice lung affected with asthma while decrease that of IL-17A, IL-23, and RORγt. NF-κB pathway activation elicited by OVA was suppressed by Rbs inside the pulmonary tissues. Rbs played significantly in the reduction of airway inflammation induced by OVA which with modulating NF-κB pathway activation. PRACTICAL APPLICATIONS: Simultaneous therapy with medicine and food is strategically significant for disease prevention and treatment in traditional Chinese medicine. Rbs is a diterpene glycoside isolated from Rubus suavissimus. The anti-inflammatory and anti-asthmatic mechanism dependent of Rbs need further study clinically. The goal of current investigation is to explore the anti-inflammatory as well as anti-asthmatic activity of Rbs in mouse models of OVA-induced experimental allergic asthma. Results of the present study are scientifically supportive for the use of Rbs as an adjunctive reagent for clinical treatment of allergic asthma.

6.
Chem Commun (Camb) ; 2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32167108

RESUMO

A highly chemoselective platinum-catalyzed mono-lateral diboration of dialkynylsilanes for the construction of silicon-tethered alkynyl diborylalkenes is described, in which tris(4-methoxyphenyl)phosphine was found to be an effective ligand for the cis-addition of diboron agents to the silicon-tethered alkynes, and the chiral ligand (AFSi-Phos)-mediated diboration of dialkynylsilanes resulted in the desymmetric construction of silicon-stereogenic centers with promising enantioselectivity.

7.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 51(2): 185-192, 2020 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-32220186

RESUMO

Objective: To investigate the effect and mechanism of static progressive stretching (SPS) in different durations on traumatic knee contracture in rats. Methods: Seventy male Wistar rats were randomly divided into three groups, including surgical modeling group ( n=50), control group (CON, no surgery, no treatment, n=10) and trauma without immobilization group (TRA, no treatment, n=10). The knee contracture model was established, and 50 surgical modeling rats were randomly divided into five groups including static progressive stretching treatment for 20 minutes group (S20 min, n=10), treatment for 30 minutes group (S30 min, n=10), treatment for 40 minutes group (S40 min, n=10), untreatment group (UNT, no SPS, n=10) and modeling group (MOD, n=10, euthanized after immobilization for histological staining and Western blot). Individuals in the S20 min, S30 min, and S40 min groups were anesthetized and submitted to SPS. One treatment session took place every other day. A total of 8 sessions were given till the final treatment session on the day 16. On the day 0, 8, and 16 of intervention, the range of joint motion (ROM) and gait analysis were measured and compared. After the ROM measurements and gait analysis, the rats were euthanized on the day 16 and the samples were stained with HE and Masson methods. The changes of pathological organization were observed. Western blot was used to detect the expressions of transforming growth factor-ß1 (TGF-ß1) and interleukin-6 (IL-6). Results: ① ROM:the ROM of S30 min group recovered similar to that of the S20 min and S40 min groups after 8 days of treatment ( P>0.05), and was the best among all the surgical modeling groups after 16 d of treatment ( P<0.05). The ROM of S20 min, S30 min and S40 min groups significantly improved on the day 8 and day 16 comparing with that on day 0 ( P<0.01). ② Gait analysis: the stands in the S30min group improved best on the day 8 and day 16 ( P<0.05) , and better than that on day 0 ( P<0.05). The stride length of the S30 min group progressed similar to that of the S40 min group on the day 8 ( P>0.05), and there was no difference among three groups on the day 16 ( P>0.05). The stride length of the S30 min group appeared to recover more quickly on the day 8 ( P<0.05), and those of S20 min and UNT groups recovered significantly on the day 16 ( P<0.05). In addition, the swings in the S30 min group improved best ( P<0.05), and it appeared to recover better on the day 16 ( P<0.05). There was no statistical difference in terms of the swing speed among the four surgical modeling groups on the day 8 ( P>0.05). The swing speed of the S30min group increased most than those of the other three groups ( P<0.05), and it was much better on the day 8 and day 16 comparing with that on the day 0 ( P<0.05 ). ③ HE and Masson staining: the fibrosis and inflammation of the S30min group were significantly suppressed comparing to the other groups on the day 16. ④ Western blot: The protein expression levels of TGF-ß1 and IL-6 were significantly lower than those in the other intervention groups including the S20 min, S40 min and UNT groups on the day 16 ( P<0.05). Conclusion: Static progressive stretching treatment for 30 min could significantly improve the traumatic knee contracture in rats. The mechanism may be that the SPS decreased the expressions of TGF-ß1 and IL-6, reduced the adhesion and inflammation of joint capsule. Therefore it relieved the pain and increased the joint mobility by reconstructing the structure of the capsule and suppressing the fibrotic changes.


Assuntos
Contratura , Articulação do Joelho/fisiopatologia , Exercícios de Alongamento Muscular , Animais , Fenômenos Biomecânicos , Contratura/terapia , Interleucina-6/metabolismo , Cápsula Articular , Masculino , Amplitude de Movimento Articular , Ratos , Ratos Wistar , Fator de Crescimento Transformador beta1/metabolismo
8.
J Med Food ; 23(4): 440-452, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32186945

RESUMO

The chemopreventive effects of various mixed cereal grain (MCG) samples on azoxymethane (AOM, 10 mg/kg) and dextran sulfate sodium (DSS, 0.02 g/mL)-induced colorectal cancer (CRC) in C57BL/6J mice were studied. The main MCG preparation consisted of fermented brown rice (FBR), glutinous brown rice, glutinous Sorghum bicolor, glutinous Panicum miliaceum, Coix lacryma-jobi, and black soybean at an appropriate mixing ratio. Other MCG preparations contained rice coated with 5% Phellinus linteus and 5% Curcuma longa (MCG-PC) or 10% Phellinus linteus (MCG-P) or 10% Curcuma longa (MCG-C). Consumption of dietary MCG-PC by CRC mice significantly increased colon length, decreased the ratio of colon weight to length, and reduced the number of colon tumors. Similar effects, although to a lower extent, were observed in CRC mice fed with MCG-P, followed by those fed with MCG-C, MCG, FBR, or white rice. MCG-PC significantly suppressed colonic neoplasia and decreased the levels of various cytokines (tumor necrosis factor: Tnf, interleukin 1 beta: Il1b, interleukin 6: Il6, and interferon gamma: Ifnγ) in serum and colon tissue of the CRC mice. In addition, MCG-PC increased the mRNA expressions of tumor suppressor protein p53 (Tp53) and cyclin-dependent kinase inhibitor 1A (Cdkn1a), activated pro-apoptotic caspase 3 (Casp3), and reduced expressions of both mRNA and protein of inducible nitric oxide synthase 2 (Nos2), prostaglandin-endoperoxide synthase 2 (Ptgs2), and cyclin D1 (Ccnd1) in colon tissue. These findings suggest that compared with other cereal grain preparations, MCG-PC had a greater activity against AOM/DSS-induced CRC by reducing intestinal inflammation and modulating the expression of certain carcinogenesis related factors (Nos2, Ptgs2, Tp53, Cdkn1a, Ccnd1, and Casp3) in colon tissue of CRC mice.

9.
J Am Chem Soc ; 142(7): 3577-3582, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32011130

RESUMO

Four water-soluble hydrazone-based three-dimensional (3D) flexible organic frameworks FOF-1-4 have been synthesized from a semirigid tetracationic tetraaldehyde and four flexible dihydrazides. 1H NMR spectroscopy indicated the quantitative formation of FOF-1-4 in D2O, while dynamic light scattering experiments revealed that, depending on the concentration, these porous frameworks display hydrodynamic diameters ranging from 50 to 120 nm. The porosity of the frameworks is confirmed by ethanol vapor adsorption experiments of the solid samples as well as the high loading capacity for a 2.3 nm porphyrin guest in water. The new water-soluble frameworks exhibit low cytotoxicity and form inherent pores with diameters of 5.3 or 6.7 nm, allowing rapid inclusion of proteins such as bovine serum albumin and green and orange fluorescent proteins, and efficient delivery of the proteins into normal and cancer cells. Flow cytometric analysis reveals percentages of the delivered cells up to 99.8%.

10.
ChemSusChem ; 13(8): 2007-2011, 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32011109

RESUMO

Highly efficient Ru-catalyzed selective C-C or C-O bond cleavage of polyols (e.g., crude glycerol) for N-hydroxyethylation or N-acetonylation of amines was achieved through the hydrogen-borrowing approach. A variety of amines were transformed to the desired amino alcohols/ketones in moderate-to-excellent yields, opening up new avenues for generation of oxygenated pharmaceuticals and fine chemicals from renewable raw materials. The use of new redox-active catalysts containing bisphosphine/thienylmethylamine ligands allows this hydrogen-borrowing system to be operated selectively under both basic and acidic conditions.

11.
J Med Food ; 23(4): 459-464, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32109191

RESUMO

This study was to compare the anticolitis activity of fresh Saengshik (FSS) with heated Saengshik (HSS) with dextran sulfate sodium (DSS)-induced experimental colitis mouse model. Both FSS- and HSS-fed colitis mice exhibited the effects of the increase in the body weight, the alleviation in the colon shortening, and the reduction of the ratio of colon weight to length. However, FSS-fed colitis mice showed a much more significant decrease in DSS-induced tissue damage by mucosal edema and crypt deficiency than did HSS-fed ones. Besides, FSS contributed to decreasing the serum levels of proinflammatory cytokines (tumor necrosis factor-alpha and interleukin-1 beta) and inhibiting the colonic mRNA expressions of these cytokines in colitis tissue of the mice. FSS also resulted in the lower colonic mRNA expression level of inflammation-related inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in colitis mice than did HSS. Overall results confirmed Saengshik, especially FSS, inhibits more effectively against DSS-induced inflammation reaction in colitis mice than HSS.

12.
Mol Cell Biol ; 40(6)2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-31932481

RESUMO

Intestinal epithelial autophagy is crucial for host defense against invasive pathogens, and defects in this process occur frequently in patients with inflammatory bowel disease (IBD) and other mucosal disorders, but the exact mechanism that activates autophagy is poorly defined. Here, we investigated the role of RNA-binding protein HuR (human antigen R) in the posttranscriptional control of autophagy-related genes (ATGs) in the intestinal epithelium. We found that targeted deletion of HuR in intestinal epithelial cells (IECs) specifically decreased the levels of ATG16L1 in the intestinal mucosa. Intestinal mucosa from patients with IBD exhibited reduced levels of both HuR and ATG16L1. HuR directly interacted with Atg16l1 mRNA via its 3' untranslated region and enhanced ATG16L1 translation, without affecting Atg16l1 mRNA stability. Circular RNA circPABPN1 blocked HuR binding to Atg16l1 mRNA and lowered ATG16L1 production. HuR silencing in cultured IECs also prevented rapamycin-induced autophagy, which was abolished by overexpressing ATG16L1. These findings indicate that HuR regulates autophagy by modulating ATG16L1 translation via interaction with circPABPN1 in the intestinal epithelium.

13.
Arch Insect Biochem Physiol ; 103(2): e21634, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31587360

RESUMO

Pteromalus puparum is a gregarious pupal endoparasitoid with a wide host range. It deposits eggs into pierid and papilionid butterfly pupae. Glutathione S-transferases (GSTs) are a family of multifunctional detoxification enzymes that act in xenobiotic metabolism in insects. Insect genome projects have facilitated identification and characterization of GST family members. We identified 20 putative GSTs in the P. puparum genome, including 19 cytosolic and one microsomal. Phylogenetic analysis showed that P. puparum GSTs are clustered into Hymenoptera-specific branches. Transcriptomic data of embryos, larvae, female pupae, male pupae, female adults, male adults, venom glands, carcass, salivary glands, and ovaries revealed stage-, sex-, and tissue-specific expression patterns of GSTs in P. puparum. This is the most comprehensive study of genome-wide identification, characterization, and expression profiling of GST family in hymenopterans. Our results provide valuable information for understanding the metabolic adaptation of this wasp.


Assuntos
Glutationa Transferase/genética , Proteínas de Insetos/genética , Vespas/genética , Sequência de Aminoácidos , Animais , Embrião não Mamífero/química , Embrião não Mamífero/metabolismo , Feminino , Perfilação da Expressão Gênica , Glutationa Transferase/química , Glutationa Transferase/metabolismo , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Larva/genética , Larva/metabolismo , Masculino , Filogenia , Pupa/genética , Pupa/metabolismo , Alinhamento de Sequência , Vespas/crescimento & desenvolvimento , Vespas/metabolismo
14.
Sci Total Environ ; 708: 134596, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31780158

RESUMO

In this study, the effects of nitrogen and phosphorus supply on biodiesel production from Scenedesmus obliquus with glucose as the carbon source were investigated. It was found that sufficient phosphorus could further improve biodiesel production under nitrogen starvation. S. obliquus was cultivated in soybean processing wastewater. The removal efficiencies of carbon oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) after 8-day cultivation were 72%, 95%, and 54%, respectively. Moreover, the fatty acid productivity after eight-day cultivation reached as high as 99.3 mg·L-1·d-1, which was 1.15 times higher than the highest efficiency using a glucose culture. This result was due to two naturally-formed stages occurring with sufficient phosphorus: nitrogen sufficiency stage for biomass and nitrogen starvation stage for lipid accumulation. It verified the conclusion of the roles of nitrogen and phosphorus obtained in the glucose culture and provided an economic and environmentally friendly choice for biodiesel production with efficient soybean wastewater treatment.

15.
Arch Insect Biochem Physiol ; 103(2): e21632, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31621105

RESUMO

Biogenic amines (BAs), such as octopamine, tyramine, dopamine, serotonin, and acetylcholine regulate various behaviors and physiological functions in insects. Here, we identified seven genes encoding BA biosynthetic enzymes and 16 genes encoding BA G protein-coupled receptors in the genome of the endoparasitoid wasp, Pteromalus puparum. We compared the genes with their orthologs in its host Pieris rapae and the related ectoparasitic wasp Nasonia vitripennis. All the genes show high (>90%) identity to orthologs in N. vitripennis. P. puparum and N. vitripennis have the smallest number of BA receptor genes among the insect species we investigated. We then analyzed the expression profiles of the genes, finding those acting in BA biosynthesis were highly expressed in adults and larvae and those encoding BA receptors are highly expressed in adults than immatures. Octα1R and 5-HT7 genes were highly expressed in salivary glands, and a high messenger RNA level of 5-HT1A was found in venom apparatuses. We infer that BA signaling is a fundamental component of the organismal organization, homeostasis and operation in parasitoids, some of the smallest insects.


Assuntos
Aminas Biogênicas/metabolismo , Borboletas/genética , Proteínas de Insetos/genética , Vespas/genética , Sequência de Aminoácidos , Animais , Borboletas/química , Borboletas/metabolismo , Borboletas/parasitologia , Embrião não Mamífero/química , Embrião não Mamífero/metabolismo , Feminino , Perfilação da Expressão Gênica , Interações Hospedeiro-Parasita , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Larva/genética , Larva/metabolismo , Masculino , Filogenia , Pupa/genética , Pupa/metabolismo , Alinhamento de Sequência , Vespas/enzimologia , Vespas/crescimento & desenvolvimento , Vespas/metabolismo
16.
Angew Chem Int Ed Engl ; 59(2): 790-797, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31829499

RESUMO

A novel and unusual palladium-catalyzed [4+2] annulation of cyclopropenes with benzosilacyclobutanes is reported. This reaction occurred through chemoselective Si-C(sp2 ) bond activation in synergy with ring expansion/insertion of cyclopropenes to form new C(sp2 )-C(sp3 ) and Si-C(sp3 ) bonds. An array of previously elusive bicyclic skeleton with high strain, silabicyclo[4.1.0]heptanes, were formed in good yields with excellent diastereoselectivity under mild conditions. An asymmetric version of the reaction with a chiral phosphoramidite ligand furnished a variety of chiral bicyclic silaheterocycle derivatives with good enantioselectivity (up to 95.5:4.5 er). Owing to the mild reaction conditions, the good stereoselectivity profile, and the ready availability of the functionalized precursors, this process constitutes a useful and straightforward strategy for the synthesis of densely functionalized silacycles.

17.
Urol Oncol ; 38(5): 401-409, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31870724

RESUMO

OBJECTIVE: To determine whether Prostate Imaging-Reporting and Data System version 2 (PIRADS v2) and neutrophil-to-lymphocyte ratio(NLR) improve the detection of clinically significant prostate cancer(csCaP) in men with prostate-specific antigen (PSA) <10 ng/ml at first biopsy. METHODS: Univariable and multivariable binary logistic regression analysis were used to screen for independent risk factors of csCaP. The multivariable model based on the risk factors was to build the nomogram predicting csCaP and assessed by receiver operator characteristic curve analysis, calibration plot, and decision curve analysis. RESULTS: This retrospective study included 335 men with PSA < 10 ng/ml who underwent initial biopsy. A total of 78 (23.3%) men had csCaP. The nomogram was built based on the multivariable model including age, digital rectal examination, free prostate-specific antigen, PIRADS v2, and NLR. It had high area under the curve of 0.876 and was well calibrated in internal validation. Decision curve analysis also demonstrated that it would improve the prediction of csCaP. CONCLUSION: PIRADS v2 and NLR improve the detection of csCaP in men with PSA < 10 ng/ml at first biopsy. Due to lack of external validation, relatively small cohort and homogenous population, the study has several limitations. Despite of this, the nomogram based on our study is a promising tool for patients to understand their risk of csCaP and for urologists to make clinical decisions.

18.
Urol Int ; 104(1-2): 113-124, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31846966

RESUMO

OBJECTIVE: To investigate the potential risk factors of infectious complications following ureteroscopy (URS). MATERIALS AND METHODS: Studies reporting risk factors of infectious complications following URS were searched via PubMed, EMBASE, Cochrane Library, and Web of Science databases up to August 30, 2019. OR or mean difference (MD) with 95% CI was calculated to assess the potential risk factors. RESULTS: A total of 14 studies containing 9,532 patients were included. Positive preoperative urine culture was the most significant risk factor (OR 2.95, 95% CI 1.96-4.43, p < 0.01), followed by female gender (OR 1.95, 95% CI 1.48-2.57, p < 0.01), diabetes mellitus (OR 1.55, 95% CI 1.13-2.13, p < 0.01), pre- and postoperative stent (OR 1.53, 95% CI 1.11-2.11, p = 0.01, OR 1.44, 95% CI 1.01-2.03, p = 0.04, relatively), and extended operative time (MD -11.54, 95% CI -16.10 to 6.98, p < 0.01). Age (MD -2.59, 95% CI -5.36 to 0.18, p = 0.07), cumulative stone diameter (MD -1.54; 95% CI -4.63 to 1.55, p = 0.33), and renal insufficiency (OR 1.22, 95% CI 0.80-1.88, p = 0.36) were not the potential risk factors. CONCLUSION: The prevalence of infectious complications following URS was correlated with female gender, diabetes mellitus, preoperative urine culture, pre- and postoperative stent insertion, and extended operative time. Publication bias and high heterogeneity were observed in some risk factors. Further studies are warranted for a valid conclusion.

19.
PLoS One ; 14(12): e0224997, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31790414

RESUMO

Seasonal variation in the availability of floral hosts or pollinators is a key factor influencing diversity in plant-pollinator communities. In seasonally dry Neotropical habitats, where month-long periods of extreme drought are followed by a long rainy season, flowering is often synchronized with the beginning of precipitation, when environmental conditions are most beneficial for plant reproduction. In the Brazilian Cerrado, a seasonally dry ecosystem considered one of the world's biodiversity hotspots for angiosperms, plants with shallow root systems flower predominantly during the rainy season. Foraging activity in social bees however, the major pollinators in this biome, is not restricted to any particular season because a constant supply of resources is necessary to sustain their perennial colonies. Despite the Cerrado's importance as a center of plant diversity, the influence of its extreme cycles of drought and precipitation on the dynamics and stability of plant-pollinator communities is not well understood. We sampled plant-pollinator interactions of a Cerrado community weekly for one year and used network analyses to characterize intra-annual seasonal variation in community structure. We also compared seasonal differences in community robustness to species loss by simulating extinctions of plants and pollinators. We find that the community shrinks significantly in size during the dry season, becoming more vulnerable to disturbance due to the smaller pool of floral hosts available to pollinators during this period. Major changes in plant species composition but not in pollinators has led to high levels of turnover in plant-pollinator associations across seasons, indicated by in interaction dissimilarity (<3% of shared interactions). Aseasonal pollinators, which mainly include social bees and some solitary specialized bees, functioned as keystone species, maintaining robustness during periods of drastic changes in climatic conditions.

20.
Huan Jing Ke Xue ; 40(11): 5164-5172, 2019 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854586

RESUMO

To evaluate the emission characteristics of carbon dioxide (CO2) and nitrous oxide (N2O) in the Loess Plateau, a field in situ study was conducted from July 2017 to July 2018 under two land-use types (15 year old apple orchard and wheat field) using static chamber-gas chromatographic techniques. Four treatments were conducted in this experiment as follows:apple orchard with fertilization (AF), apple orchard without fertilization (ACK), wheat field with fertilization (WF), and wheat field without fertilization (WCK). The results showed that CO2 and N2O emissions varied significantly with the season, and the emission peaks appeared after rainfall and fertilization. The cumulative amount of CO2 and N2O emissions from the AF treatment were 7.14% and 461.4% higher than that of the WF treatment, respectively. However, the cumulative amount of CO2 emissions under the ACK treatment was 10.41% lower than that of the WCK treatment, whereas the cumulative amount of N2O emissions was 109.5% higher than that of the WCK treatment. The N2O emission flux from the orchard was significantly positively correlated with soil temperature and moisture (P<0.01). The CO2 emission fluxes from the orchard and wheat field were significantly positively correlated with topsoil temperature (P<0.05) but were not correlated with topsoil moisture. Thus, the combination of field management and environmental factors affected soil CO2 and N2O emissions. The fertilizer regime and soil hydrothermal conditions were the main factors influencing the characteristics of CO2 and N2O emissions under different land-use types.

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