Tracking Regulatory Mechanism of Trace Fe on Graphene Electromagnetic Wave Absorption

Polarization and conductance losses are the fundamental dielectric attenuation mechanisms for graphene-based absorbers, but it is not fully understood in revealing the loss mechanism of affect graphene itself. For the first time, the reduced graphene oxide(RGO) based absorbers are developed with regulatory absorption properties and the absorption mechanism of RGO is mainly originated from the carrier injection behavior of trace metal Fe nanosheets on graphene. Accordingly, the minimum reflection loss(RLmin) of Fe/RGO-2composite reaches-53.38 dB(2.45 mm), and the effective absorption bandwidth achieves 7.52 GHz(2.62 mm) with lower filling loading of 2 wt%. Using off-axis electron hologram testing combined with simulation calculation and carrier transport property experiments, we demonstrate here the carrier injection behavior from Fe to graphene at the interface and the induced charge accumulation and rearrangement, resulting in the increased interfacial and dipole polarization and the conductance loss. This work has confirmed that regulating the dielectric property of graphene itself by adding trace metals can not only ensure good impedance matching, but also fully exploit the dielectric loss ability of graphene at low filler content,which opens up an efficient way for designing lightweight absorbers and may be extended to other types materials.

Preparation of CIP@TiO_(2) composite with broadband electromagnetic wave absorption properties

Scholars aim for the improved impedance matching (Z) of materials while maintaining their excellent wave absorption properties. Based on the hydrolysis characteristics of isopropyl titanate, a simple preparation process for the coating of carbonyl iron powder(CIP) with TiO_(2) was designed. Given the TiO2coating, the Z of the CIP@TiO_(2) composite was adjusted well by decreasing the dielectric constant. Moreover, the interfacial polarization of CIP@TiO_(2) was enhanced. Ultimately, the electromagnetic-wave (EMW) absorption property of the CIP@TiO_(2)composite was improved substantially, the minimum reflection loss reached-46.07 dB, and the effective absorption bandwidth can reach 8 GHz at the composite thickness of 1.5 mm. Moreover, compared with CIP, the oxidation resistance of CIP@TiO_(2)showed remarkable improvement. The results revealed that the oxidation starting temperature of CIP@TiO_(2) as about 400℃,whereas the uncoated CIP had an oxidation starting temperature of approximately 250℃. Moreover, the largest oxidation rate temperature of CIP@TiO_(2) increased to around 550℃. This work opens up a novel strategy for the production of high-performance EMW absorbers via structural design.

A review:Research progress on multi-target neuroprotective effects of n-butylphthalide extracted from Apium graveolens seeds

Apium graveolens,an annual herb belonging to the family of Apiaceae,is widely distributed in North and South America,Southern Europe,Africa and Asia.Apium graveolens seeds have a rich history in traditional Chinese medicine for treating hypertension,headaches,vertigo and epilepsy.N-butylphthalide,originally extracted from Apium graveolens seeds,represents a first-in-class drug developed independently in China.Its broad pharmacological activities on nervous system disorders have garnered significant attention from researchers globally.This review focuses on the pharmacological research of n-butylphthalide on central nervous system diseases,including ischemic stroke,Alzheimer’s disease,Parkinson’s disease and amyotrophic lateral sclerosis.The purpose is to pave the way for future study on the mechanistic targets of n-butylphthalide.

Application of Psychological Elastic Development Model in Postoperative Trauma Growth of Patients with Esophageal Cancer

Purpose: Use the psychological resilience development model to formulate effective nursing measures, and explore the impact of relevant nursing measures on the psychological resilience and post-traumatic growth of patients. Methods: Using a general data sheet, post-traumatic growth scale, and psychological resilience scale, 100 patients discharged from the hospital after esophageal cancer were investigated in groups, and statistical software spss26.0 was used for statistical analysis. Results: The psychological resilience and post-traumatic growth levels of the experimental group were significantly higher than those of the control group, the P-value. Conclusion: As a common gastrointestinal tumor, esophageal cancer is traumatized by surgery. Not only will there be more discomfort during hospitalization, but also a series of complications will still occur after discharge, such as pain, weakness, and other discomforts, which will cause the patient’s emotions. Subject to strong fluctuations, the patient suffers great psychological trauma. After being discharged from the hospital, caregivers need to master more related skills when caring for patients, which is time-consuming and labor-intensive, and often causes the patients to feel the emotion of dragging the family members. Under the condition of both physical and psychological pressure, patients often appear fearful and uneasy, and suffer great psychological trauma, which leads to low levels of psychological resilience and post-traumatic growth of patients, and related nursing interventions based on Rutter’s psychological development model It can significantly improve the patient’s psychological flexibility, improve the patient’s post-traumatic growth level, promote the patient’s physical and mental recovery, make the patient produce positive emotions, increase positive psychological changes, and thereby improve the patient’s quality of life after discharge.

The ORR electron transfer kinetics control via Co-N_(x) and graphitic N sites in cobalt single atom catalysts in alkaline and acidic media

Cost-effective 3d transition metal(TM) based single atom catalysts(SACs) for oxygen reduction reaction(ORR) are potential alternatives for Pt-based electrocatalysts in fuel cells and metal-air batteries.Understanding the effects of SACs’ properties and active site composition on the catalytic performance is significant to construct highly efficient catalysts. Here, we successfully promote the activity of cobalt single atoms decorated on N-doped carbon nanosheets via tuning the content of different nitrogen components, which outperforms most reported cobalt SACs. The activity and kinetics show positive correlation trends with the content of Co-Nxand graphitic N, serving as the main active sites.Furthermore, ORR kinetics in alkaline media can be positively affected by the conductivity of catalysts while no similar relation is observed in acidic media. The slight loss of Co-Nxsites engenders a mild change of performance in alkaline media, while the decrease of Co-Nxsite activity due to chemical oxidation of carbon support and the loss of Co-Nxsites in acidic media exacerbate the degradation of performance. Our work provides an insight into the relation between ORR electron transfer kinetics and active sites in 3d TM based SACs.

Chemical constituents and pharmacological properties of Sarcandra glabra(Thunb.)Nakai.

Sarcandra glabra(Thunb.)Nakai.,belonging to Chloranthaceae genus of Sarcandra family,is widely used as the common Chinese herbal medicine in folk.As a traditional medicinal agent,a wide spectrum of chemical constituents have been isolated from the S.glabra,including sesquiterpenoids,triperpenoids,flavonoids,coumarins,phenolic acids and volatile oil.Modern pharmacological studies have shown that S.glabra has many biological activities such as anti-cancer,hepatoprotective activity,anti-inflammatory and anti-asthmatic activities.For the further development of this plant,the primary chemical constitutions of S.glabra and their activities have been summarized in this study.

Aromatic compounds from Solanum nigrum L.and their antioxidant activities

Solanum nigrum L.,belonging to the genus Solanum of Solanaceae family,is widely distributed in temperate and tropical regions of the world.It possesses the effects of clearing away heat and detoxification.A wide spectrum of chemical constituents have been isolated from the Solanum nigrum L.,including lignans,steroids,etc.The structures of the eight compounds were determined by comprehensive spectroscopic analyses.It is noteworthy that compounds 1–4,6 and 8 have been isolated from Solanum nigrum L.for the first time.All compounds were evaluated for their antioxidant activities by ABTS and DPPH assays.Based on the results,Solanum nigrum L.could be used as a new natural antioxidant in biomedical applications.

Research progress on the main chemical constituents and pharmacological effects of Piper betle L.

The Piper betle,belonging to Piper genus of the Piperaceae family,is an evergreen and perennial creeper used in several traditional medicines.This plant has been known to possess antioxidant,antitumor,antibacterial,anti-inflammatory and antimalarial activities.A wide range of chemical compounds including alkaloids,simple phenylpropanoids,lignans,flavonoids,steroids,triterpenoids,sesquiterpenes,monoterpenes have been isolated from this plant.The present review summarized the information concerning phytochemistry and biological activity of P.betle,providing references for the future research of this plant.

A review:Chemical constituents and pharmacological activities of Solanum lyratum Thunb.

Solanum lyratum Thunb.belonging to the family Solanaceae,is a common Chinese herbal medicine in folk.It has been used for the treatment of colds,fever,jaundice hepatitis,cholecystitis,cholelithiasis,nephritis,edema and cancer.Previous phytochemical studies on S.lyratum have led to the identification of many chemical constituents,including steroidal saponins,alkaloids,terpenoids,flavonoids,quinonoids,phenylpropanoids,organic acids and several other kinds of compounds,which showed diverse bioactivities,such as anticancer,anti-inflammatory and antioxidant activities.This paper summarized the primary chemical constituents and pharmacological effects of S.lyratum to provide reference for its further development and utilization.

Volatile oil from Litsea lancilimba Merr.: a review of its chemical structure and biological activity

Litsea lancilimba Merr.is a Cinnamomum plant of Lauraceae.Phytochemical investigations of the Litsea lancilimba Merr.have resulted in the isolation of Volatile oil,flavonoid glycosides,tannins,alkaloids,lignans,organic acids and so on.Studies have showed that volatile oil is the main chemical component.Recent trials have demonstrated the efficacy of Litsea lancilimba Merr.in strengthening the function of stomach.The fruits have also been demonstrated to possess anti-inflammatory and bacteriostatic activities.This review deals mainly with the chemical structure and biological activities of Litsea lancilimba Merr.oil.

Research review on the main chemical constituents and pharmacological activities of Viburnum awabuki

Viburnum awabuki(V.awabuki),belonging to the Viburnum genus,is an ideal tree species for landscaping.Phytochemical investigations of the V.awabuki have resulted in the isolation and identification of coumarins,lignans,sesquiterpenes,diterpenes and triterpenes.It has been reported that the extracts of V.awabuki have multiple pharmacological activities,including anti-tumor,anti-oxidant,plant growth inhibitory and neurite outgrowth-promoting activities.The research progress on the chemical constituents of V.awabuki and pharmacological activities were summarized in this review.

Progress on chemical constituents and pharmacological effects of Piper nigrum L.

Piper nigrum L.,belonging to Piper genus of the Piperaceae family,is a medicinal and edible plant.Studies have shown that there are many chemical constituents in this plant,including alkaloids,lignans,steroids and other compounds.In addition,some chemical components of P.nigrum have potential values to treat cancer,inflammation and other diseases.Research progress on the chemical constituents and pharmacological effects of P.nigrum was reviewed in this study to better explore its potential medicinal value.

Research review on the main chemical constituents and pharmacological effects of Tripterygium hypoglaucum (Levl.) Hutch.

Tripterygium hypoglaucum(Levl.)Hutch.(THH),which belongs to Tripterygium genus of Celastraceae family,is widely used as the common Chinese herbal medicine.It has been reported that the chemical constituents of T.hypoglaucum include monoterpenoids,sesquiterpenoids,diterpenoids,triterpenoids,sesquiterpene alkaloids,flavonoids,anthraquinone derivatives,et al.These compounds showed a wide range of bioactivities,such as anti-inflammatory,anti-cancer,immunosuppressive,anti-HIV,anti-fertility and insecticidal activities.In this paper,we summarized the chemical constituents and pharmacological activities of T.hypoglaucum to provide a reference for its further research and developement.

Isolation and identification of chemical constituents from Elephantopus scaber Linn.

Elephantopus scaber L.,as a popular Chinese medicinal herb of the Compositae family,is widely distributed in America,Africa and Asia.In the present study,five compounds were isolated from the 70%EtOH extract of the whole herb from Elephantopus scaber L.,including two lignans and three flavones.Their chemical structures were identified based on NMR spectroscopic analysis and comparison with the data reported in literature.It is noteworthy that compounds 1-5 were isolated from Elephantopus scaber L.for the first time and their chemotaxonomic significance was discussed.

Isolation and characterization of lignans from the leaves of Isatis indigotica Fortune

A phytochemical investigation of 80%EtOH exact of Isatis indigotica Fortune leaves yielded ten lignans(1-10),including six furofurans lignans(1-6),one arylnaphthalenes lignans(7)and three tetrahydrofurans lignans(8-10).Their structures were determined by HRESIMS spectroscopic data and extensive NMR analyses.Among them,compounds 6,9 and 10 were isolated from the genus oi Isatis for the first time.

Research progress on chemical constituents in Periploca forrestii and their pharmacological activities

Periploca forrestii Schltr.belonging to the family of Apocynaceae,is one of the“three treasures of Miao medicine”,which was utilized by the Miao people in China for the treatment of rheumatoid arthritis,fractures and wound.Phytochemical investigations have discovered that the main constituents of Periploca forrestii were steroids,terpenoids,flavonoids and their glycosides,flavanols,quinones and phenylpropanoids.Modern pharmacological studies have shown that it possesses a wide range of biological activities,such as anti-inflammatory,anti-rheumatoid arthritis,anticancer,immunosuppressive,neuroprotective and other properties.This paper summarized the primary chemical constituents and pharmacological effects of Periploca forrestii,hoping to provide a reference for its further development and utilization.

Phenolic compounds from Peanut testa

Phytochemical investigation of peanut testa(the seed coat of Arachis hypogaea L.)led to the isolation of eight phenolic compounds,including caffeic acid(1),methyl caffeate(2),ethyl caffeate(3),methyl protocatechuate(4),ethyl protocatechuate(5),butyl protocatechuate(6),(E)-p-hydroxycinnamic acid methyl ester(7),and resveratrol(8).The structures of the compounds were elucidated through spectroscopic data analysis and comparison with the previously reported literature.Among them,compounds 2,3,5,and 6 were obtained from Arachis hypogaea L.for the first time.

Studies on chemical constituents of Ailanthus altissima(Mill.)Swingle and their antioxidant activity

Ailanthus altissima(Mill.)Swingle is a deciduous tree belonging to the Simaroubaceae family.The root and stem bark are traditional medicines for treating many diseases,such as diarrhea,dreaminess and intestinal tract bleeding.Phytochemical investigation of Ailanthus altissima(Mill.)Swingle led to the isolation of eight compounds.Chemical structures of these compounds were identified by analyzing their NMR spectroscopic data.Among them,compounds 1,4,5,6 and 8 were isolated from Ailanthus Desf.for the first time.The antioxidant activities of these compounds were determined by DPPH radical scavenging method.

Phenolic compounds from Elephantopus scaber L.

Eight compounds,(+)-syringaresinol(1),apigenin(2),3,5-dimethoxy-4-hydxyphenylpropanol(3),3,4,5-trimethoxy benzoic acid,(4)ferulaic acid(5),trans-p-hydroxycinnamic methyl ester(6),4-hydroxy-3-methoxybenz-oic acid(7)and p-methoxy benzoic acid(8)were isolated from the 70%ethanol extract of the whole herb of Elephantopus scaber L.The structures of all compounds were identified by spectral data analysis.All compounds were obtained for the first time from Elephantopus scaber L..

Isolation,structure elucidation and antioxidant activity of natural products from the root bark of Ailanthus altissima(Mill.)Swingle

Eight compounds(1-8)were isolated from Ailanthus altissima(Mill.)Swingle,including four lignans,three phenylpropanoids and a simple aromatic compound,their structures were identified by nuclear magnetic resonance spectra and mass spectrometry data.Among them,compounds 1,3,5 and 8 were first obtained from this genus.In addition,free radical scavenging ability of compounds 1-8 were evaluated using DPPH,ABTS,and FRAP assays and the results showed that compound 2 exhibited potent antioxidant activity in DPPH and ABTS radical scavenging assays and compound 7 showed the highest value of FRAP radical scavenging.