Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
Add more filters










Publication year range
1.
Org Lett ; 26(17): 3575-3580, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38636450

ABSTRACT

We introduce switchable chemoselectivity strategies based on the hydrazone phosphaketene intermediate to synthesize three classes of 1,2,4-diazaphosphol derivatives. First, the five-membered heterocyclic P and O anion intermediates acted as nucleophilic agents in the selective construction of C-P and C-O bonds. Second, the phosphinidene served as a phosphorus synthon, allowing for the formation of C-P and C-N bonds. Finally, a stepwise mechanism, supported by DFT calculations, was invoked to explain the reaction selectivity.

2.
J Mol Graph Model ; 130: 108782, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38685182

ABSTRACT

The interactions of the micro-mechanism of hydroxymethanesulfonic acid (HMSA) with the typical small organic molecule in atmospheric (X = methanol, formaldehyde, formic acid, methyl formate, dimethyl ether, acetone) has been investigated by density functional theory (DFT), quantum theory of atoms in molecules (QTAIM), Generalized Kohn-Sham Enery Decomposition Analysis (GKS-EDA) and the atmospheric clusters dynamic code (ACDC). The results of DFT show that the stable six- to eight-membered ring structures are easily formed in HMSA-X clusters. According to the topological analysis results of the AIM theory and the IRI method, a strong hydrogen bonding interaction is present in the complex. GKS-EDA results show that electrostatic energy is the main contributor to the interaction energy as it accounts for 51 %-55 % of the total attraction energy. The evaporation rates of HMSA-HMSA and HMSA-HCOOH clusters were much lower than those of the other HMSA complexes. In addition, the Gibbs energy of formation (ΔG) of HMSA-X dimers is investigated under atmosphere temperature T = 217-298 K and p = 0.19-1.0 atm, the ΔG decreased with decreasing of the atmosphere temperature and increased with the decrease of atmospheric pressure, indicating that the low temperature and high pressure may significantly facilitate to the formation of dimers.


Subject(s)
Atmosphere , Hydrogen Bonding , Atmosphere/chemistry , Thermodynamics , Organic Chemicals/chemistry , Models, Molecular , Quantum Theory , Mesylates/chemistry , Static Electricity , Temperature
3.
Insects ; 13(5)2022 May 18.
Article in English | MEDLINE | ID: mdl-35621805

ABSTRACT

Cuticle sclerotization is critical for insect survival. Laccase2 (Lac2) is a phenol oxidase that plays a key role in cuticle formation and pigmentation in a variety of insects. However, the function of Lac2 in whitefly, Bemisia tabaci, remains unclear. In this study, we identified a BtLac2 gene in B. tabaci MEAM1 and found that BtLac2 was expressed in all stages. It was highly expressed in the egg stage, followed by nymph and adult. Moreover, the expression of BtLac2 was higher in the cuticle than in other tissues. Knockdown of BtLac2 in nymphs produced thinner and fragile cuticles, which significantly increased the mortality rate, extended the development duration of nymphs, and decreased the emergence rate of adults. This result demonstrates that BtLac2 plays an important role in the cuticle hardening of B. tabaci and suggests a potential management strategy using RNAi to knock down BtLac2 expression.

4.
Int J Qual Stud Health Well-being ; 17(1): 2028348, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35103558

ABSTRACT

PURPOSE: This qualitative study explores the meaning of life and end-of-life coping strategies among patients in China with advanced lung cancer. METHODS: We conducted in-depth interviews with 21 hospitalized patients with advanced lung cancer and analysed the data using the 7-step Colaizzi method. RESULTS: The analysis revealed themes in patients' experiences and feelings about living with a terminal illness. These include: 1) The core of the meaning of life is "self-iteration," which includes self-recognition and cherishing life; 2) The existence form of the meaning of life is "yu-wei," including self-reliance and altruism; 3) The meaning of life is embodied in three levels: the past, present, and future. The past includes gratitude, guilt and remorse, and avoidance; the present includes using the support system, positive response, independence, and integrity; the future includes accompanying relatives, preparing for death, living a high quality of life, and worrying. CONCLUSION: Meaning of life is a multidimensional and diverse concept among patients with advanced lung cancer. Medical care providers and family members can provide targeted professional guidance and psychological support according to patients' characteristics to help them discover their meaning of life, improve their quality of life, and achieve a positive end-of-life perspective.


Subject(s)
Lung Neoplasms , Quality of Life , Adaptation, Psychological , Family , Humans , Qualitative Research
5.
Insects ; 14(1)2022 Dec 20.
Article in English | MEDLINE | ID: mdl-36661930

ABSTRACT

BACKGROUND: Flower thrips (Frankliniella intonsa, IFT) and west flower thrips (Frankliniella occidentalis, WFT) are often found together on the host plant in China. WFT is an important invasive species that seems to outcompete the native IFT. In order to clarify the interspecific competitions between the two thrips, this study measured the population development of IFT and WFT under sexual and parthenogenetic reproductive modes on two hosts (fresh lentil bean pods with/without honey and pepper plants at seedling/flowering stages) in the laboratory. RESULTS: When reared on fresh lentil bean pods (with/without honey), WFT population size was lower in mixed species populations compared to single species populations but the presence of WFT had nor negative effect on IFT population size. These results were dependent of the reproductive mode. When honey was supplied, the ratio of female-to-male in the progeny of WFT produced under sexual reproductive mode increased significantly in the presence of IFT. On pepper seedlings, mixed populations were more favorable to the population development of IFT at the seedling stage, but more favorable to WFT at the flowering stage. CONCLUSIONS: In the early stage of WFT invasion and colonization, the emergence of flowering and honey (nectar) sources may have a positive effect on the population development of WFT.

6.
Insect Sci ; 28(1): 35-46, 2021 Feb.
Article in English | MEDLINE | ID: mdl-31912953

ABSTRACT

Insect neuropeptides play an important role in regulating physiological functions such as growth, development, behavior and reproduction. We identified temperature-sensitive neuropeptides and receptor genes of the cotton whitefly, Bemisia tabaci. We identified 38 neuropeptide precursor genes and 35 neuropeptide receptors and constructed a phylogenetic tree using additional data from other insects. As temperature adaptability enables B. tabaci to colonize a diversity of habitats, we performed quantitative polymerase chain reaction with two temperature stresses (low = 4 °C and high = 40 °C) to screen for temperature-sensitive neuropeptides. We found many neuropeptides and receptors that may be involved in the temperature adaptability of B. tabaci. This study is the first to identify B. tabaci neuropeptides and their receptors, and it will help to reveal the roles of neuropeptides in temperature adaptation of B. tabaci.


Subject(s)
Genome, Insect/physiology , Hemiptera/genetics , Neuropeptides/genetics , Receptors, Neuropeptide/genetics , Transcription, Genetic/physiology , Animals , Cold Temperature/adverse effects , Genes, Insect , Hemiptera/physiology , Hot Temperature/adverse effects , Neuropeptides/metabolism , Receptors, Neuropeptide/metabolism , Stress, Physiological/genetics
7.
Sci Rep ; 7(1): 3623, 2017 06 15.
Article in English | MEDLINE | ID: mdl-28620217

ABSTRACT

The whitefly Bemisia tabaci is a phloem-feeding pest that lives predominantly on herbaceous species and causes serious damage to hosts. Whitefly saliva is thought to contain proteins that modulate plant defences and facilitate feeding. A predicted secreted protein, laccase 1 (LAC1), was found in the salivary gland transcriptome of B. tabaci and might be existed in the watery saliva of B. tabaci. As LAC1 has a potential role in detoxification of secondary plant compounds in insects, we speculated that it may participate in the insect's response to plant defences. Here, we cloned the complete cDNA of LAC1 and found that (1) LAC1 was highly expressed in the salivary gland (SG) and midgut; (2) LAC1 transcript level in head (containing SG) was 2.1 times higher in plant-fed than in diet-fed whiteflies and 1.6 times higher in the head and 23.8 times higher in the midgut of whiteflies that fed on jasmonic acid (JA)-sprayed plants than on control plants; and (3) silencing LAC1 decreased the survival rate of plant-fed whiteflies but had a marginal effect on whiteflies raised on an artificial diet. These results indicate that LAC1 enables whiteflies to overcome the chemical defences of host plants and might act as an effector in saliva.


Subject(s)
Hemiptera/physiology , Host-Parasite Interactions , Laccase/metabolism , Plants/parasitology , Animals , Gene Expression Regulation , Hemiptera/classification , Hemiptera/enzymology , Laccase/genetics , Solanum lycopersicum/parasitology , Phylogeny
9.
PLoS One ; 11(7): e0159719, 2016.
Article in English | MEDLINE | ID: mdl-27459697

ABSTRACT

Alternative splicing (AS) contributes to the complexity of the mammalian proteome and plays an important role in diseases, including infectious diseases. The differential AS patterns of these transcript sequences between the healthy (HS3A) and mastitic (HS8A) cows naturally infected by Staphylococcus aureus were compared to understand the molecular mechanisms underlying mastitis resistance and susceptibility. In this study, using the Illumina paired-end RNA sequencing method, 1352 differentially expressed genes (DEGs) with higher than twofold changes were found in the HS3A and HS8A mammary gland tissues. Gene ontology and KEGG pathway analyses revealed that the cytokine-cytokine receptor interaction pathway is the most significantly enriched pathway. Approximately 16k annotated unigenes were respectively identified in two libraries, based on the bovine Bos taurus UMD3.1 sequence assembly and search. A total of 52.62% and 51.24% annotated unigenes were alternatively spliced in term of exon skipping, intron retention, alternative 5' splicing and alternative 3' splicing. Additionally, 1,317 AS unigenes were HS3A-specific, whereas 1,093 AS unigenes were HS8A-specific. Some immune-related genes, such as ITGB6, MYD88, ADA, ACKR1, and TNFRSF1B, and their potential relationships with mastitis were highlighted. From Chromosome 2, 4, 6, 7, 10, 13, 14, 17, and 20, 3.66% (HS3A) and 5.4% (HS8A) novel transcripts, which harbor known quantitative trait locus associated with clinical mastitis, were identified. Many DEGs in the healthy and mastitic mammary glands are involved in immune, defense, and inflammation responses. These DEGs, which exhibit diverse and specific splicing patterns and events, can endow dairy cattle with the potential complex genetic resistance against mastitis.


Subject(s)
Alternative Splicing , Mammary Glands, Animal/metabolism , Mastitis, Bovine/genetics , Transcriptome , Animals , Case-Control Studies , Cattle , Chromosomes/genetics , Female , Humans , Mammary Glands, Animal/microbiology , Mastitis, Bovine/metabolism , Mastitis, Bovine/microbiology , Quantitative Trait Loci , Staphylococcus aureus
10.
Gene ; 587(1): 70-5, 2016 Aug 01.
Article in English | MEDLINE | ID: mdl-27106119

ABSTRACT

FoxA transcription factors play vital roles in regulating the expression of organ-specific genes. BmSGF1, the sole FoxA family member in Bombyx mori, is required for development of the silk gland. However, the function of BmSGF1 in development of the nervous system in the silkworm remains unknown. Here, we show that the amino acids sequence of BmSGF1 is evolutionarily conserved in its middle region from Trichoplax adhaerens to human and diverged from the homologues in most other species in its N-terminal region. BmSGF1 expresses in the nervous system at the embryonic stage. Knockdown of Bmsgf1 by RNA interference (RNAi) results in abnormal development of axons. Therefore, our results demonstrate that BmSGF1 is an indispensable regulator for neurodevelopment.


Subject(s)
Bombyx/growth & development , Bombyx/metabolism , Insect Proteins/metabolism , Transcription Factors/metabolism , Animals , Insect Proteins/chemistry , Nervous System , Phylogeny , Transcription Factors/chemistry
11.
Yi Chuan ; 38(1): 62-71, 2016 01.
Article in Chinese | MEDLINE | ID: mdl-26787524

ABSTRACT

To explore the association between single nucleotide polymorphisms (SNPs) in the promoter region of the inner centromere protein (INCENP) gene and bovine semen quality, the haplotypes in 250 Chinese Holstein bulls were detected using PCR-RFLP method in this study. Two SNPs (g.-556 G>T, rs 136823901 and g.-692 C>T, rs 211010999) and three haplotypes (CG, TT, TG) were identified in the promoter region of INCENP. The genotype frequency and allele frequency of these two SNPs as well as the correlation between different SNP haplotype combinations and bovine semen quality were then analyzed. Our results showed that fresh sperm motility of the GT genotype was significantly higher than that of the GG genotype (P<0.05) at the SNP site g.-556 G>T, while fresh and frozen-thawed sperm motilities of the haplotype combinations H1H1(CCGG), H1H3(CTGT), H2H3(TTGT) and H3H3(TTTT) were significantly higher than that of H1H2 (P<0.05). To further study the possible mechanisms by which g.-556 G>T and g.-692 C>T affect semen quality, three haplotype plasmids were respectively transfected into MLTC-1 cells. The TG haplotype demonstrated the highest luciferase activity, suggesting that g.-556 G>T and g.-692 C>T are functional mutations which could regulate INCENP gene expression by affecting promoter activity and thus affect semen quality.


Subject(s)
Cattle/genetics , Chromosomal Proteins, Non-Histone/genetics , Promoter Regions, Genetic , Spermatozoa/metabolism , Animals , Base Sequence , Cattle/metabolism , Chromosomal Proteins, Non-Histone/metabolism , Gene Frequency , Genotype , Haplotypes , Male , Molecular Sequence Data , Polymorphism, Single Nucleotide , Semen Analysis , Spermatozoa/chemistry
12.
J Integr Plant Biol ; 52(9): 793-800, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20738723

ABSTRACT

Purification of photosystem II (PSII) core complexes is a time-consuming and low-efficiency process. In order to isolate pure and active PSII core complexes in large amounts, we have developed a fast method to isolate highly active monomeric and dimeric PSII core complexes from spinach leaves by using sucrose gradient ultracentrifugation. By using a vertical rotor the process was completed significantly faster compared with a swing-out rotor. In order to keep the core complexes in high activity, the whole isolation procedure was performed in the presence of glycine betain and pH at 6.3. The isolated pigment-protein complexes were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, absorption spectroscopy, 77 K fluorescence spectroscopy and high performance liquid chromatography. Our results show that this method is a better choice for quick and efficient isolation of functionally active PSII core complexes.


Subject(s)
Photosystem II Protein Complex/isolation & purification , Spinacia oleracea/chemistry , Chromatography, High Pressure Liquid , Dimerization , Electrophoresis, Polyacrylamide Gel , Spectrometry, Fluorescence , Ultracentrifugation
13.
Chem Phys Lipids ; 2007 Jan 23.
Article in English | MEDLINE | ID: mdl-17316588

ABSTRACT

This article has been withdrawn consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The Publisher apologizes for any inconvenience this may cause.

SELECTION OF CITATIONS
SEARCH DETAIL
...