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IntroductionThe present study aimed to examine the effects of online game addiction on reduced academic achievement motivation, and the mediating role of learning engagement among Chinese college students to investigate the relationships between the three variables.MethodsThe study used convenience sampling to recruit Chinese university students to participate voluntarily. A total of 443 valid questionnaires were collected through the Questionnaire Star application. The average age of the participants was 18.77 years old, with 157 males and 286 females. Statistical analysis was conducted using SPSS and AMOS.Results(1) Chinese college students’ online game addiction negatively affected their behavioral, emotional, and cognitive engagement (the three dimensions of learning engagement); (2) behavioral, emotional, and cognitive engagement negatively affected their reduced academic achievement motivation; (3) learning engagement mediated the relationship between online game addiction and reduced academic achievement motivation.

Primula filchnerae, an endangered plant endemic to China, has drawn people’s attention in recent years due to its ornamental value in flower. It was rarely recorded since being described in 1902, but it was rediscovered in 2009 and is now known from a limited number of sites located in Hubei and Shaanxi Provinces. Since the species is still poorly known, a number of unanswered questions arise related to it: How has P. filchnerae responded to past climate change and how might it respond in the future? Why was P. filchmerae so rarely collected during the past century? We assembled geographic coordinates for P. filchnerae through the field surveys and website searches, and then used a maximum entropy model (MaxEnt) to simulate its potential suitable distribution in six periods with varied carbon emission levels by combining bioclimatic and environmental factors. MaxEnt showed that Min Temperature of the Coldest Month (bio6) and Precipitation of the Coldest Quarter (bio19) affected P. filchnerae’s distribution most, with an aggregate contribution >60% and suitable ranges above −5 °C and below 40 mm, respectively. We also analyzed potential habitat distribution in various periods with differing impacts of climate change compared to today’s suitable habitats, and in most cases, Shaanxi and Sichuan remained the most stable areas and with possible expansion to the north under various carbon emission scenarios, but the 2050s SSP5-8.5 scenario may be an exception. Moreover, we used MaxEnt to evaluate population shifts, with various scenarios indicating that geometric center would be concentrated in Sichuan Province in China. Finally, conservation strategies are suggested, including the creation of protected areas, long-term monitoring, raising public awareness of plant conservation, situ conservation measures, assisted migration, and species introduction. This study demonstrates how P. filchnerae may have adapted to changes in different periods and provides a scientific basis for germplasm conservation and management.

Development of rapid analytical methods and establishment of toxic component limitation standards are of great importance in quality control of traditional Chinese medicine. Herein, an on-line extraction electrospray ionization mass spectrometry (oEESI-MS) coupled with a novel whole process integral quantification strategy was developed and applied to direct determination of nine key aconitine-type alkaloids in 20 Aconitum proprietary Chinese medicines (APCMs). Multi-type dosage forms (e.g., tablets, capsules, pills, granules, and liquid preparation) of APCM could be determined directly with excellent versatility. The strategy has the characteristics of high throughput, good tolerance of matrix interference, small amount of sample (∼0.5 mg) and reagent (∼240 μL) consumption, and short analysis time for single sample (

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Litsea cubeba fruits was found to possess strong contact toxicity against the cigarette beetle Lasioderma serricorne adults and the booklouse Liposcelis bostrychophila, with LD50 values of 27.33µg/adult and 71.56µg/cm², respectively, and also showed strong fumigant toxicity against the two stored product insects with LC50 values of 22.97 and 0.73mg/L, respectively. The essential oil obtained by hydrodistillation was investigated by GC MS. The main components of the essential oil were identified to be E-citral (geranial) (27.49%), Z-citral (neral) (23.57%) and d-limonene (18.82%) followed by β-thujene (3.34%), β-pinene (2.85%), α-pinene (2.57%), 6-methyl-5-hepten-2-one (2.40%) and linalool (2.36%). Citral (Z/E-citral), d-limonene, β-pinene, α-pinene and linalool were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. Citral and linalool showed strong contact toxicity against L. serricorne and L. bostrychophila (LD50=11.76, 12.74µg/adult and 20.15, 99.97µg/cm², respectively) and fumigant toxicity against L. serricorne and L. bostrychophila (16.54, 18.04mg/L air and 0.14, 0.71mg/L air, respectively). Otherwise, citral, d-limonene and linalool were strongly repellent against the cigarette beetle L. serricorne as the essential oil whereas β-pinene and α-pinene exhibited weaker repellency against the cigarette beetle compared with the positive control, DEET. Moreover, except α-pinene and linalool, the other three compounds as well as the essential oil exhibited comparable repellency against the booklouse relative to DEET. [ABSTRACT FROM AUTHOR]

During our screening program for agrochemicals from Chinese medicinal herbs and wild plants, the essential oil of Cinnamomum camphora leaves was found to possess strong fumigant and contact toxicity against Lasioderma serricorne adults with LC50/LD50 values of 2.5 mg/L air and 21.25 µg/adult, respectively. The essential oil obtained by hydrodistillation was investigated by GC and GC-MS. The main components of the essential oil were identified to be D-camphor (40.54%), linalool (22.92%), cineole (11.26%), and 3,7,11-trimethyl-3-hydroxy-6,10-dodecadien-1-yl acetate (4.50%). Bioactivity-directed chromatographic separation on repeated silica gel columns led to the isolation of D-camphor and linalool. D-camphor and linalool showed strong fumigant toxicity (LC50 = 2.36 and 18.04 mg/L air, resp.) and contact toxicity (LD50 = 13.44 and 12.74 µg/adult, resp.) against L. serricorne. The results indicate that the essential oil of C. camphora and its active compounds had the potential to be developed as natural fumigants and insecticides for control of L. serricorne. [ABSTRACT FROM AUTHOR]

The aim of this research was to determine larvicidal activity of the ethanol extract of Inula racemosa Hook. f. (Compositae) roots against the larvae of the Culicidae mosquito Aedes albopictus and to isolate any larvicidal constituents from the extract. Based on bioactivity-guided fractionation, 11,13-dihydroisoalantolactone (1), macrophyllilactone E (2), 5α-epoxyalantolactone (3), and epoxyisoalantolactone (4) were isolated and identified as the active constituents. Compounds 1 and 2 exhibited strong larvicidal activity against the early fourth-instar larvae of A. albopictus with LC50 values of 21.86 µg/mL and 18.65 µg/mL, respectively, while the ethanol extract had a LC50 value of 25.23 µg/mL. Compounds 3 and 4 also possessed larvicidal activity against the Asian tiger mosquitoes with LC50 values of 29.37 µg/mL and 35.13 µg/mL, respectively. The results indicated that the ethanol extract of I. racemosa and the four isolated constituents have potential for use in the control of A. albopictus larvae and could be useful in the search of newer, safer, and more effective natural compounds as larvicides. [ABSTRACT FROM AUTHOR]