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1.
Fitoterapia ; 150: 104840, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-33535108

RESUMO

Five new compounds, including a pair of diphenylcyclopentenone enantiomers (±)-phomopsisin A (1), a sesquiterpenoid 15-hydroxylithocarin A (2), a new diketopiperazine alkaloid prenylcyclotryprostatin A (3) and 7-hydroxy-cis-L(-)-3,6-dibenzyl-2,5-dioxopiperazine (6), along with five known compounds were isolated from the fungus Phomopsis asparagi. Their structures were elucidated on the basis of spectroscopic analyses (1D and 2D NMR), theoretical electronic circular dichroism (ECD) calculation, modified Mosher's method, and X-ray crystallography. The racemates of (±)-phomopsisin A showed inhibition on α-glucosidase with IC50 of 30.07 ± 0.75 µM (positive control acarbose, 121 ± 2.7 µM).

2.
Poult Sci ; 100(4): 100976, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33607317

RESUMO

Reproduction performance is one of the most important economic traits for the poultry industry. Intriguingly, apple pectic oligosaccharide (APO) could promote gastrointestinal function and immune function to improve performance; however, literature about APO on reproduction performance in breeders is limited. This study aimed to determine whether APO administration can improve reproduction performance and ovary function of broiler breeders with different egg laying rates. Two hundred and fifty six Arbor Acres broiler breeders (48-week-old) were used in a 2 × 2 factorial design with 2 egg laying rates (average [AR] and low [LR]) and 2 dietary levels of APO (0 and 200 mg/kg APO). Results showed that the LR breeders presented higher egg weight but lower egg laying rate, qualified egg rate, and feed efficiency than the AR breeders (P(laying) < 0.05). Also, the LR breeders had decreased serum Anti-Müllerian hormone, leptin, and antioxidant enzyme (superoxide dismutase, total antioxidant capacity) levels than the AR breeders (P(laying) ≤ 0.05). Dietary supplementation with APO improved egg weight, feed efficiency, as well as egg albumen quality (higher albumen height and Haugh unit) (P(APO) < 0.05), and decreased the concentration of pro-inflammatory cytokine levels (interleukin [IL]-1ß, IL-8) in serum (P(APO) ≤ 0.05). The apoptosis rate and pro-apoptosis-related gene expression (caspase 9 and Bax) in the ovary of LR breeders were higher, while the anti-apoptosis-related gene expression (Bcl-2, PCNA) was lower in LR compared with the AR breeders (P(laying) < 0.05). Dietary supplementation with APO decreased the caspase 9 and Bax expression in LR breeders (P(interaction) < 0.05), and increased the Bcl-2 and PCNA expression in the 2 breeders (P(APO) < 0.05). These findings indicate that breeders with a lower egg laying rate exhibit lower antioxidant capacity and high cell apoptosis in the ovary. Dietary supplementation with APO might improve albumen quality and antioxidant capacity, and decrease the inflammatory factors and ovary apoptosis-related genes expression to improve ovary function. Moreover, the effect of APO on decreasing ovarian pro-apoptosis-related gene expression was more pronounced in lower reproductive breeders.

3.
J Clin Oncol ; 39(3): 227-237, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33326255

RESUMO

PURPOSE: To evaluate the effects of daratumumab, lenalidomide, and dexamethasone (D-Rd) versus lenalidomide and dexamethasone (Rd) on patient-reported outcomes (PROs) in the phase III MAIA study. PATIENTS AND METHODS: PROs were assessed on the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-item and the EuroQol 5-dimensional descriptive system at baseline and every 3 months during treatment. By mixed-effects model, changes from baseline are presented as least squares means with 95% CIs. RESULTS: A total of 737 transplant-ineligible (TIE) patients with newly diagnosed multiple myeloma were randomly assigned to D-Rd (n = 368) or Rd (n = 369). Compliance with PRO assessments was high at baseline (> 90%) through month 12 (> 78%) for both groups. European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30-item global health status scores improved from baseline in both groups and were consistently greater with D-Rd at all time points. A global health status benefit was achieved with D-Rd, regardless of age (< 75 and ≥ 75 years), baseline Eastern Cooperative Oncology Group (ECOG) performance status score, or depth of response. D-Rd treatment resulted in significantly greater reduction in pain scores as early as cycle 3 (P = .0007 v Rd); the magnitude of change was sustained through cycle 12. Reductions in pain with D-Rd were clinically meaningful in patients regardless of age, ECOG status, or depth of response. Similarly, PRO improvements were observed with D-Rd and Rd on the EuroQol 5-dimensional descriptive system visual analog scale score. CONCLUSION: D-Rd compared with Rd was associated with faster and sustained clinically meaningful improvements in PROs, including pain, in transplant-ineligible patients with newly diagnosed multiple myeloma regardless of age, baseline ECOG status, or depth of treatment response.

4.
Poult Sci ; 100(1): 196-205, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33357682

RESUMO

This study was conducted to determine the effects of supplemental dietary benzoic acid on production performance, egg quality, intestinal morphology, and intestinal microbiota of laying hens. A total of seven hundred twenty 45-wk-old Lohman pink-shell laying hens were randomly allocated to 3 dietary treatments: control (CON), diet supplemented with 1,000 mg/kg benzoic acid (BA1), and 2,000 mg/kg benzoic acid (BA2). Each treatment included 10 replicates of 24 hens; laying hens were monitored for 16 wk. Overall, the results indicate that benzoic acid supplementation had no effect on laying rate, feed intake, feed conversion ratio, and breaking rate; however, a decrease in egg weight (P < 0.01) was observed in the BA2 group. Albumen height and Haugh unit (HU) were also linearly increased in the BA1 and BA2 groups (linear effect, P < 0.05). An increase in duodenum villus height (V) (quadratic effect, P = 0.041) and crypt depth (C) (linear effect, P = 0.012) was observed in the BA2 group, whereas an increased jejunum C and decreased V/C (quadratic effect, P < 0.05) in the BA1 group. Moreover, an increase in ileum V and C (quadratic effect, P < 0.05) was observed in the BA1 group. Microbial richness and diversity were reduced in the BA2 group (P < 0.01). An increase in the abundance of Clostridia (class), Clostridiales (order), Ruminococcaceae (family), and Lachnospiraceae (family) was noted in the BA1 group, whereas an enrichment of Bacteroides caecicola (species) was observed in the BA2 group. The HU positively correlated with genus Sphaerochaeta and Enorma (r = 0.56, 0.56; P < 0.05) but negatively correlated with Romboutsia, Subdoligranulum, Helicobacter, and Mucispirillum (r = -0.58, -0.49, -0.48; -0.70; P < 0.05). In conclusion, dietary supplementation with benzoic acid had no effect on production performance, but it significantly improved egg quality. In addition, 1,000 mg/kg benzoic acid positively modulated intestinal health by improving intestinal morphology and enriching microbial composition.

5.
Nat Prod Res ; : 1-8, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33319589

RESUMO

Two new nucleoside derivatives, kipukasins M (1a) and N (1b), along with one known analogue, kipukasin J (2), were obtained from the marine-derived fungus Aspergillus versicolor, which was isolated from the mud collected in the South China Sea. The structures of compounds 1a and 1b were elucidated by extensive spectroscopic analysis, mainly including 1D & 2D NMR and HRESIMS data, and the absolute configuration of 1a was further confirmed by single-crystal X-ray diffraction analysis. Interestingly, intramolecular transesterification occurs in compounds 1a and 1b, which exist as a pair of inseparable regioisomers. All isolated compounds were tested for the cytotoxic and antimicrobial activities.

6.
Appl Opt ; 59(34): 10746-10753, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33361894

RESUMO

In this paper, efficient individual and joint constant amplitude zero auto-correlation (CAZAC) precoding schemes are proposed to improve the performance of an indoor multiple-input multiple-output-orthogonal frequency division multiplexing (MIMO-OFDM)-based visible light communication (VLC) system. By considering the proposed precoding scheme, a 3×3 MIMO-OFDM VLC system with symmetrical and asymmetrical structure is set up, whose peak-to-average-power ratio (PAPR) of transmitted signal, signal-to-noise ratio (SNR), and bit error rate performance are investigated. It is shown that both individual and joint CAZAC precoding schemes can reduce the PAPR of the transmitted signal and make the SNR uniform over data subcarriers, resulting in significant performance improvement compared to the system without precoding. It is demonstrated that there are similar performance improvements for the MIMO-OFDM VLC system using the individual CAZAC precoding and joint CAZAC precoding in a symmetric scenario. At the expense of higher implementation complexity, the joint CAZAC precoding has more performance benefits than the individual CAZAC precoding for the VLC system with asymmetrical MIMO.

7.
J Org Chem ; 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-33191735

RESUMO

Nine novel polyketide-terpenoid hybrids (1-9), characterized by a 1-alkylated-3,5-dihydroxyphenyl derivative coupled with a modified farnesyl pyrophosphate (FPP) unit, were isolated from a soil-derived fungus Bipolaris zeicola. Their structures were determined by comprehensive spectroscopic data, single-crystal X-ray diffraction analyses, and electronic circular dichroism calculations. Structurally, compounds 1, 2, 5, and 6 possess a rare thiazole moiety; compounds 3 and 4 are the first examples of meroterpenoids featuring an undescribed 6/6/6/6/5 pentacyclic system and bearing a tetrahydrofuran ring fused to a polyketide and a sesquiterpenoid subunit; compounds 7 and 8 possess a rare 2H-1,4-thiazin-3(4H)-one moiety; and compound 9 represents the first example of meroterpenoid having an unusual thiazol-2(3H)-one moiety. The bioactivity assays revealed that compounds 1, 2, 5, 6, and 9 exhibited a significant immunosuppressive effect against concanavalin A (ConA)-induced T lymphocyte proliferation with IC50 values ranging from 5.6 to 8.8 µM, and compounds 1, 2, and 4 exhibited moderate cytotoxic activities with IC50 values ranging from 18.4 to 29.4 µM.

8.
Front Psychol ; 11: 558313, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33162907

RESUMO

Objective: Losing the only child is considered as the most severe kind of bereavement. It can trigger intense grief symptoms along with loss of psychosocial resources, but meanwhile, it can also lead to posttraumatic growth (PTG). The current study aimed to examine (a) whether a curvilinear relationship exists between grief and PTG and (b) the moderating role of resources-loss among Chinese bereaved parents who lost their only child (shidu parents). Methods: One hundred and ninety-nine shidu parents from five provinces completed the assessment packet covering prolonged grief symptoms and PTG, as well as resource loss. Hierarchical regression analyses were computed to examine the curvilinear relationship and the moderating effect of interpersonal loss and socio-economic loss. Results: There was no significant curvilinear relationship between grief and PTG in shidu parents. Under the high levels of interpersonal loss, shidu parents' PTG scores decreased as the severity of grief increased. However, the socio-economic loss did not show a significant moderating effect. Conclusion: The results of the current study did not show a significant curvilinear relationship between grief and PTG in shidu parents. High levels of grief coupled with high levels of interpersonal loss may interfere with their ability to achieve PTG. Therefore, evaluating degrees of interpersonal loss seems to be an important part of the treatment process when working with shidu parents. To facilitate their adaptation from a positive perspective, helping them maintain existing or develop new interpersonal relationships may be helpful.

9.
Appl Opt ; 59(32): 10194-10200, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33175797

RESUMO

In this work, a novel iterative algorithm based on an M5 model tree (M5Tree) is proposed to realize indoor positioning using a single LED and multiple photodetectors. A visible light positioning system was implemented to evaluate the algorithm performance, including the effect of the maximum depth of the tree and the number of iterations on positioning accuracy. Finally, in the same single LED positioning system, the traditional machine-learning algorithms, being k-nearest neighbor and support vector regression, were compared with the M5Tree algorithm. The simulation results demonstrate that the proposed algorithm has good positioning performance on a single LED positioning system.

10.
J Exp Bot ; 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33130897

RESUMO

Microbial symbiosis in legumes is achieved through nitrogen-fixing root nodules, which is important for sustainable agriculture. The molecular mechanisms underlying development of root nodules in polyploid legume crops are largely understudied. Through map-based cloning and QTL-seq approaches, we identified a pair of homoeologous GRAS transcription factor genes, Nodulation Signaling Pathway 2 (AhNSP2-B07 or Nb) and AhNSP2-A08 (Na), controlling nodulation in cultivated peanut (Arachis hypogaea L.), an allotetraploid legume crop, which exhibited non-Mendelian and Mendelian inheritance, respectively. The segregation of nodulation in the progeny of Nananbnb genotypes followed a 3:1 Mendelian ratio, in contrast to the 5:3 ~ 1:1 non-Mendelian ratio for nanaNbnb genotypes. Additionally, a much higher frequency of the nb allele (13%) than the na allele (4%) exists in the peanut germplasm collection, suggesting that Nb is less essential than Na in nodule organogenesis. Our findings provided the genetic basis of naturally occurred non-nodulating peanut plants, which can be potentially used for nitrogen fixation improvement in peanut. Furthermore, the results provided implications and insights into the evolution of homoeologous genes in allopolyploid species.

11.
Poult Sci ; 99(11): 5802-5813, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33142498

RESUMO

Mercuric chloride (HgCl2) is a serious environmental toxicant. So far, the toxicity mechanism of HgCl2 in chicken embryonic kidney (CEK) cells is not still fully understood. In this study, the possible molecular mechanisms of HgCl2 on apoptosis of CEK cells were investigated. Results showed that the cell morphology changed, and cell viability was significantly decreased (P < 0.05) after HgCl2 exposure. Besides, apoptosis rate was significantly increased after HgCl2 exposure (P < 0.05). The gene and protein expressions of B-cell lymphoma-2 associate X/B-cell lymphoma-2 (P < 0.05), caspase-3 (P < 0.05), and caspase-9 (P < 0.05) were significantly enhanced by HgCl2 in CEK cells. We also found that intracellular reactive oxygen species level was significantly enhanced (P < 0.05), and the flux of calcium ion to mitochondria occurred after HgCl2 exposure. In terms of molecular mechanisms, the mRNA and protein expressions associated with endoplasmic reticulum (ER) stress were significantly increased after HgCl2 exposure (P < 0.05), including glucose regulated protein 78, protein kinase RNA-like endoplasmic reticulum kinase (PERK), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP). However, pretreated with 1-µmol/L 4-phenylbutyrate (ER stress inhibitor) alleviated the apoptosis and downregulated PERK-ATF4-CHOP pathway in CEK cells. Taken together, upregulation of PERK-ATF4-CHOP pathway of ER stress induced by HgCl2 is associated with apoptosis in CEK cells.

12.
Front Psychol ; 11: 572521, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33250816

RESUMO

Although a large body of research has indicated that cyberbullying victimization is a crucial risk factor for adolescent non-suicidal self-injury (NSSI) behavior, the mediating and moderating mechanisms underlying this relationship remain unclear. To address this research gap, this study, based on the social control theory and the organism-environment interaction model, was designed to test whether school engagement mediated the relationship between cyberbullying victimization and adolescent NSSI and whether this mediating effect was moderated by sensation seeking. A sample of 1,102 adolescents (M age = 13.17; SD = 0.69) anonymously completed the questionnaires. The results showed that the positive association between cyberbullying victimization and adolescent NSSI was mediated by school engagement. Moreover, this indirect link was significant for adolescents with high-level sensation seeking but non-significant for adolescents with low-level sensation seeking. These findings highlight school engagement as a potential mechanism linking cyberbullying victimization to adolescent NSSI, and high sensation seeking was an important risk factor to amplify this indirect effect. Intervention programs aimed at reducing NSSI among adolescents may benefit from the current research.

13.
Lancet Haematol ; 7(12): e874-e883, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33242444

RESUMO

BACKGROUND: In part 1 of the two-part CASSIOPEIA study, treatment before and after autologous haematopoietic stem-cell transplantation (HSCT) with daratumumab plus bortezomib, thalidomide, and dexamethasone (D-VTd) significantly improved rates of stringent complete response and progression-free survival versus bortezomib, thalidomide, and dexamethasone (VTd) in patients with newly diagnosed multiple myeloma. METHODS: CASSIOPEIA is an ongoing randomised, open-label, active-controlled, parallel-group, phase 3 trial done at 111 academic and community practice centres in Europe. Transplantation-eligible adults with newly diagnosed multiple myeloma were randomly assigned (1:1) to D-VTd or VTd. Treatment consisted of four 28-day cycles of induction therapy before autologous HSCT and two 28-day cycles of consolidation therapy after. In this prespecified secondary analysis, patient-reported outcomes were assessed using the European Organization for Research and Treatment of Cancer quality of life questionnaire-core 30-item (EORTC QLQ-C30) and EuroQol 5-dimensional descriptive system (EQ-5D-5L) questionnaire at baseline, after induction (cycle 4, day 28), and after consolidation (day 100 after autologous HSCT). The analysis was done in all patients in the intention-to-treat population with a baseline and at least one post-baseline patient-reported outcome assessment. The trial is registered at ClinicalTrials.gov (NCT02541383). FINDINGS: Between Sept 22, 2015, and Aug 1, 2017, 1085 patients were enrolled and randomly assigned D-VTd (n=543) or VTd (n=542). Questionnaire completion rates were high at baseline (511 [94%] of 543 in the D-VTd group vs 510 [94%] of 542 in the VTd group). Compliance rates (calculated from the number of completed surveys as a proportion of the predicted number of participants still on study treatment) were high at post-induction (431 [84%] of 513 vs 405 [80%] of 509) and post-consolidation (414 [90%] of 460 vs 386 [88%] of 438) assessments and were similar between treatment groups. Mean changes in global health status scores from baseline to post-induction were not different between the D-VTd group (3·8 [95% CI 1·6 to 6·0]) and VTd group (2·9 [0·7 to 5·1]; p=0·43), or from baseline to post-consolidation between the two groups (D-VTd group, 9·7 (95% CI 7·4 to 11·9) vs VTd group, 8·7 (6·5 to 11·0; p=0·45). Improvements from baseline in EORTC QLQ-C30 global health status and EQ-5D-5L visual analogue scale scores were observed in post-consolidation scores in both groups. Post-consolidation scores showed significantly greater mean decreases in pain (-23·3 [95% CI -26·6 to -20·0] in the D-VTd group vs -19·7 [-23·0 to -16·3] in the VTd group; p=0·042), significantly smaller reductions in cognitive functioning (-5·0 [-7·6 to -2·4] vs -7·9 [-10·6 to -5·3]; p=0·036), and significantly greater improvements in emotional functioning (13·0 [10·4 to 15·5] vs 9·5 [6·9 to 12·1]; p=0·013) and in constipation (-3·2 [-7·3 to 0·9] vs 1·8 [-2·4 to 6·0]; p=0·025) with D-VTd versus VTd. Between-group differences in change from baseline for all other scales were not significant. INTERPRETATION: D-VTd and VTd were associated with on-treatment health-related quality of life improvements from baseline in transplantation-eligible patients with newly diagnosed multiple myeloma. The significantly greater reductions in pain, less deterioration of cognitive functioning, and greater emotional functioning improvements complement the clinical benefits observed with D-VTd versus VTd, and support the addition of daratumumab to standard regimens in patients with newly diagnosed multiple myeloma. FUNDING: Intergroupe Francophone du Myélome, The Dutch-Belgian Cooperative Trial Group for Hematology Oncology, and Janssen Research and Development.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Bortezomib/uso terapêutico , Dexametasona/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Qualidade de Vida/psicologia , Talidomida/uso terapêutico , Anticorpos Monoclonais/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica , Bortezomib/farmacologia , Dexametasona/farmacologia , Feminino , Humanos , Masculino , Talidomida/farmacologia
15.
Cancer Res ; 80(23): 5203-5215, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33051252

RESUMO

DNA methylation contributes to malignant transformation, but little is known about how the methylation drives colorectal cancer evolution at the early stages. Here we identify aberrant INA (α-internexin) gene methylation in colon adenoma and adenocarcinoma by filtering data obtained from a genome-wide screen of methylated genes. The gene encoding INA, a type IV intermediate filament, was frequently hypermethylated in CpG islands located in the promoter region. This hypermethylation preferentially occurred in large tumors and was a prognostic marker for poor overall survival in patients with colorectal cancer. This type of epigenetic alteration silenced INA expression in both adenoma and adenocarcinoma tissues. Gene silencing of INA in colorectal cancer cells increased cell proliferation, migration, and invasion. Restored INA expression blocked migration and invasion in vitro and reduced lung metastasis in vivo. Mechanistically, INA directly inhibited microtubule polymerization in vitro and decreased intracellular microtubule plus-end assembly rates. A peptide array screen surveying the tubulin-binding sites in INA identified a tubulin-binding motif located in the N-terminal head domain that plays a tumor-suppressive role by binding to unpolymerized tubulins and impeding microtubule polymerization. Thus, epigenetic inactivation of INA is an intermediate filament reorganization event that is essential to accelerate microtubule polymerization in the early stages of colorectal cancer. SIGNIFICANCE: This work provides insight into the epigenetic inactivation of INA, a novel identified tumor suppressor, which increases microtubule polymerization during colorectal cancer progression.

16.
Clin Epigenetics ; 12(1): 162, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33126908

RESUMO

BACKGROUND AND AIMS: Stool DNA testing is an emerging and attractive option for colorectal cancer (CRC) screening. We previously evaluated the feasibility of a stool DNA (sDNA) test of methylated SDC2 for CRC detection. The aim of this study was to assess its performance in a multicenter clinical trial setting. METHODS: Each participant was required to undergo a sDNA test and a reference colonoscopy. The sDNA test consists of quantitative assessment of methylation status of SDC2 promoter. Results of real-time quantitative methylation-specific PCR were dichotomized as positive and negative, and the main evaluation indexes were sensitivity, specificity, and kappa value. All sDNA tests were performed and analyzed independently of colonoscopy. RESULTS: Among the 1110 participants from three clinical sites analyzed, 359 and 38 were diagnosed, respectively, with CRC and advanced adenomas by colonoscopy. The sensitivity of the sDNA test was 301/359 (83.8%) for CRC, 16/38 (42.1%) for advanced adenomas, and 134/154 (87.0%) for early stage CRC (stage I-II). Detection rate did not vary significantly according to age, tumor location, differentiation, and TNM stage, except for gender. The follow-up testing of 40 postoperative patients with CRC returned negative results as their tumors had been surgically removed. The specificity of the sDNA test was 699/713 (98.0%), and unrelated cancers and diseases did not seem to interfere with the testing. The kappa value was 0.84, implying an excellent diagnostic consistency between the sDNA test and colonoscopy. CONCLUSION: Noninvasive sDNA test using methylated SDC2 as the exclusive biomarker is a clinically viable and accurate CRC detection method. CHINESE CLINICAL TRIAL REGISTRY: Chi-CTR-TRC-1900026409, retrospectively registered on October 8, 2019; http://www.chictr.org.cn/edit.aspx?pid=43888&htm=4 .

17.
J Nat Prod ; 83(11): 3397-3403, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33089690

RESUMO

Bioassay-directed isolation of secondary metabolites from an extract of Penicillium chrysogenum TJ403-CA4 isolated from the medicinally valuable arthropod Cryptotympana atrata afforded five new and 10 known compounds (1-15). All the compounds (except 14) belong to a minor class of highly rigid 6-5-5-5-fused tetracyclic cyclopiane-type diterpenes known to be exclusively produced by members of the Penicillium genus. The structures and absolute configurations of the new compounds (1-5) were elucidated by extensive spectroscopic analyses, including HRESIMS and 1D and 2D NMR, single-crystal X-ray diffraction, and comparison of the experimental electronic circular dichroism data. Compounds 1 and 2 represent the first examples of cyclopianes bearing a C-20 carboxyl group; compound 3 represents the first example of a cyclopiane with a gem-hydroxymethyl group; compound 4 represents the second example of a cyclopiane bearing a hydroxy group at C-7; compound 5 represents the first example of a cyclopiane bearing a hydroxy group at C-8. Compounds 2 and 3 exhibited activity against MRSA, with MIC values of 4.0 and 2.0 µg/mL, respectively. In addition, the structure-antibacterial activity relationship (SAR) of compounds 1-15 is discussed.

18.
Front Psychol ; 11: 572486, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33117238

RESUMO

Although vast research has shown that cybervictimization is a significant risk factor of adolescent's internet addiction (IA), little is known about the mediating and moderating mechanisms behind this relationship. The current study examined whether depression mediated the relationship between cybervictimization and adolescent's IA, and whether the direct and indirect effect was moderated by prosocial peer affiliation (PPA). A sample of 1,006 adolescents (Meanage = 13.16; SD = 0.67) anonymously completed the questionnaires. The results revealed that the positive association between cybervictimization and adolescent's IA was mediated by depression. Moderated mediation analysis further showed that PPA moderated the association between cybervictimization and adolescent's IA. However, this indirect effect was stronger for adolescents with high PPA than for those with low PPA, which means that the protective effects of PPA are limited. These findings highlight the mediating and moderating mechanisms between cybervictimization and adolescent's IA, and provide guidance for the prevention and intervention in adolescent's IA.

19.
Phys Chem Chem Phys ; 22(43): 25042-25053, 2020 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-33112337

RESUMO

The "specific" interaction between metal cations (Na+, Ca2+, Mg2+, and Zn2+) and the charged COO- group, and the "non-specific" interaction between these cations and the peptide backbone of a zwitterionic trialanine (Ala3) in aqueous solutions were examined in detail, using linear infrared (IR) absorptions of the COO- symmetric stretching and the amide-II (mainly the C-N stretching) modes as IR probes. Different IR spectral changes in peak positions and intensities of the two IR probes clearly demonstrate their sensitivities to nearby cation distributions in distance and population. Quantum chemistry calculations and molecular dynamics simulations were used to describe the cation-peptide interaction picture. These combined results suggest that Na+ and Ca2+ tend to bind to the COO- group in the bidentate form, while Mg2+ and Zn2+ tend to bind to the COO- group in the pseudo-bridging form. The results also show that while all three divalent cations indirectly interact with the peptide backbone with large population, Ca2+ and Mg2+ can be sometimes distributed very close to the backbone. Such a non-specific cation interaction can be moderately sensed by the C-N stretching of the amide-II mode when cations approach the polar amide C[double bond, length as m-dash]O group, and is also influenced by the NH3+ charge group located at the N-terminus. The results suggest that the experimentally observed complication of the Hofmeister cation series shall be understood as a combined specific and non-specific cation-peptide interactions.

20.
Anim Reprod Sci ; 222: 106608, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33039822

RESUMO

Spermatogenesis is important for male fertility, but has not been well-studied in Opsariichthys bidens, an economically important freshwater fish in China. In this study, there was investigation of the cytological features of spermatogenesis in O. bidens using light microscopy, transmission electron microscopy, and immunofluorescence detection of microtubules. O. bidens has tubular testis. Spermatogenesis in O. bidens is of the cystic type, in which the spermatogenic cells develop into spermatozoa in cysts. There was asynchronous development of primary spermatocytes within a single cyst. Spermiogenesis was classified as Type I, which develops into a Type I aquasperm with an oval nucleus, a small and simple midpiece, a flagellum and no acrosome. There was a nuage in spermatogonia, spermatocytes, and spermatids in different developmental stages of spermatids which may have important functions in fish spermatogenesis. Furthermore, microtubule dynamics may be involved in spermatid reshaping, material transport, and polar distribution of organelles during spermiogenesis.

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