Biomedical subjects

Di Wu

Publications and source records attributed to Di Wu.

At least 19 recordsLinked to original sources

PubMed2026

Development of a recombinant goose parvovirus VP2 neutralizing epitope-containing region vaccine adjuvanted with IL-2 and FliC for enhanced immune responses and protection against challenge.

Gosling plague (GP), caused by goose parvovirus (GPV), is a highly contagious and fatal viral disease. Vaccination is essential for disease prevention; however, conventional attenuated and inactivated vaccines have several limitations. Genetically engineered vaccines based on defined antigenic regions represent a promising alternative strategy. This study aimed to identify neutralizing epitope-containing regions within the GPV VP2 protein and develop effective recombinant vaccines. The GPV VP2 protein was divided into 11 overlapping fragments, and the anchored periplasmic expression (APEx) bacterial display system combined with flow cytometry (FCM) was used for antigenic region screening. GPV VP2-specific single-domain antibodies (VHHs) were further applied to identify neutralizing epitope-containing regions. Six neutralizing epitope-containing regions were identified and linked together to construct the VP2M recombinant antigen. The VP, VP2M, interleukin-2 (IL-2), and flagellin (FliC) genes were inserted into prokaryotic and eukaryotic expression vectors to generate protein and DNA vaccines. Three-day-old goslings were randomly assigned into 15 experimental groups for immunization. Immune responses were evaluated by measuring anti-GPV antibody levels, IgG, IgM, and IgA production, IFN-γ levels, immune-related gene expression, splenocyte proliferation, neutralizing activity, and protective efficacy against GPV challenge. The results showed that vaccines containing neutralizing epitope-containing regions induced stronger immune responses than control vaccines. Vaccinated groups exhibited increased anti-GPV antibody levels, IgG, IgM, IgA production, IFN-γ levels, immune-related gene expression, and splenocyte proliferation. Following GPV challenge, VP2M-based vaccines significantly reduced viral genome copies in the bursa of Fabricius, spleen, thymus, and intestinal tissues, accompanied by decreased histopathological lesions based on semi-quantitative scoring. Furthermore, the protective efficacy exceeded 50% in vaccines without adjuvants and reached 90% in groups containing combined IL-2 and FliC adjuvants. In conclusion, this study identifies novel neutralizing epitope-containing regions within GPV VP2 and provides a potential strategy for developing safe and effective recombinant vaccines against GP infection.

GP↗

PubMed2026

The hidden threat from food-derived carbon dots: Formation, biodistribution, and potential health risks.

Food-derived carbon dots (CDs) are a new class of carbon-based nanoparticles generated during the thermal processing of food matrices. These nanomaterials have been extensively studied for their unique fluorescence, good biocompatibility, and tunable surface chemistry in food detection, intelligent packaging, and biomedical applications. However, their nanoscale size and high surface activity have raised safety concerns regarding biological interactions, in vivo biodistribution, and potential long-term health hazards. Although CDs have traditionally been regarded as low-toxicity materials due to their favorable biocompatibility, the potential hidden risks of CDs have not received sufficient attention. CDs exhibit dose-dependent toxicity, not only accumulating in various tissues and organs but also potentially inducing oxidative stress and interfering with cellular metabolic functions. Therefore, this review summarizes the advances in sources, synthetic strategies, and core properties of CDs, with a special focus on in vivo biological interactions, fates, and potential safety challenges. In addition, it is proposed that the standardized detection and risk assessment system should be established to further explore the long-term health effects of CDs under real dietary exposure, thereby ensuring their safety and sustainable application.

Carbon Quantum Dots↗

PubMed2026

Detecting Androgenetic Origin of the Genome via Single-Nucleotide Polymorphism-Based Cell-Free DNA Screening in Dichorionic Diamniotic Twin Pregnancies With Complete Hydatidiform Moles and a Coexisting Normal Fetus: A Three-Case Report.

What is already known about this topic? ◦. Complete hydatidiform mole with a coexisting normal fetus (CHMCF) refers to a pregnancy in which a normal fetus and a complete mole coexist. ◦. CHMCF is associated with substantial maternal and fetal morbidity, including hemorrhage, severe anemia, hypertensive disorders, hyperthyroidism, prematurity, fetal loss, and an increased risk of gestational trophoblastic neoplasia. What does this study add? ◦. We report three cases of dichorionic diamniotic (DCDA) twin pregnancies with suspected CHMCF, in which single‐nucleotide polymorphism (SNP)–based cell‐free DNA (cfDNA) analysis detected the androgenetic origin of the genome implying concurrent presence of paternal uniparental diploidy and biparental diploidy in maternal plasma. ◦. To our knowledge, this is among the first case series applying SNP‐based cfDNA prospectively in this specific clinical scenario in twin pregnancy. Its prospective dual‐component detection in twins has a potential clinical decision impact on CHMCF.

Journal Article↗

PubMed2026

Magnetic nanoparticle-mediated genetic transformation and gene editing system in loquat (Eriobotrya japonica).

Loquat (Eriobotrya japonica Lindl.) is a valuable subtropical fruit tree whose genetic improvement has been significantly constrained by the absence of an efficient genetic transformation system. Although Agrobacterium-mediated transformation is the most widely used method, it proves ineffective in loquat due to the species' recalcitrance to in vitro regeneration. Pollen-based transformation offers a promising alternative by bypassing the need for tissue culture. However, the pollen wall poses a major physical barrier to the uptake of exogenous DNA. In this study, we investigated magnetic nanoparticle (MNP)-mediated transformation as a novel strategy for loquat. We confirmed that loquat pollen contains tricolporate apertures with diameters ranging from 3.0 to 5.0 μm, which are structurally suitable for the entry of MNPs-DNA. Based on this finding, we developed and optimized a transformation protocol using polyethyleneimine-coated Fe3O4 nanoparticles to deliver genetic material into loquat pollen grains. Using this approach, we successfully generated stable transgenic loquat lines, including both overexpression and gene-edited mutants. To our knowledge, this is the first report of successful MNP-mediated pollen transformation in a woody plant species. This work establishes a robust and efficient genetic transformation platform for loquat, providing a valuable tool for functional genomics and molecular breeding, as well as a potentially applicable strategy for other recalcitrant woody plants.

Eriobotrya↗

PubMed2025

The super-enhancer regulatory gene SH2D1A promotes the progression of T cell acute lymphoblastic leukemia by activating CHI3L2.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive leukemia subtype and a prevalent malignancy in children, with poor prognosis, high relapse rates, and drug resistance. Recent research has shown that super-enhancer-regulated genes play crucial roles in T-ALL progression. In this study, we identified SH2 domain containing 1 A (SH2D1A) as a gene regulated by super-enhancers, and is overexpressed, which correlates with unfavorable clinical outcomes in T-ALL. To investigate its role, we silenced SH2D1A expression in T-ALL cell models using RNA interference. This led to a significant reduction in cell proliferation, colony formation, and promoted apoptosis, as demonstrated by CCK-8 assays, soft agar colony formation, and flow cytometry analysis. In vivo, knockdown of SH2D1A significantly inhibited tumor growth and prolonged survival in mice bearing T-ALL. Mechanistically, we found that SH2D1A contributes to T-ALL progression by upregulating CHI3L2, a downstream effector that promotes cell proliferation and inhibits apoptosis. Using ChIP-Seq and RNA-seq technologies, we confirmed that SH2D1A regulates CHI3L2 expression through super-enhancer-mediated regulation in T-ALL cells. Our findings suggest that SH2D1A and CHI3L2 act as oncogenes in T-ALL, and may represent novel therapeutic targets. This research offers new insights into the molecular mechanisms of T-ALL and highlights potential avenues for therapeutic intervention.

Precursor T-Cell Lymphoblastic Leukemia-Lymphoma↗

PubMed2025

The causal relationship between steroid hormones and risk of stroke: evidence from a two-sample Mendelian randomization study.

It is unclear how steroid hormones contribute to stroke, and conducting randomized controlled trials to obtain related evidence is challenging. Therefore, Mendelian randomization (MR) technique was employed in this study to examine this association. Through genome-wide association meta-analysis, the genetic variants of steroid hormones, including testosterone/17β-estradiol (T/E2) ratio, aldosterone, androstenedione, progesterone, and hydroxyprogesterone, were acquired as instrumental variables. Analysis was done on the impact of these steroid hormones on the risk of stroke subtypes. The T/E2 ratio was associated to an elevated risk of small vessel stroke (SVS) according to the inverse variance weighted approach which was the main MR analytic technique (OR, 1.23, 95% CI: 1.05-1.44, p = 0.009). These findings were solid since no heterogeneity nor horizontal pleiotropy were found. The causal association between T/E2 and SVS was also confirmed in the replication study (p = 0.009). Nevertheless, there was no proof that other steroid hormones increased the risk of stroke. According to this study, T/E2 ratio and SVS are causally related. However, strong evidence for the impact of other steroid hormones on stroke subtypes is still lacking. These findings may be beneficial for developing stroke prevention strategies from steroid hormones levels.

Mendelian Randomization Analysis↗

PubMed2024

Integrated ubiquitomics characterization of hepatocellular carcinomas.

BACKGROUND AND AIMS: Patients with aggressive HCC have limited therapeutic options. Therefore, a better understanding of HCC pathogenesis is needed to improve treatment. Genomic studies of HCC have improved our understanding of cancer biology. However, the ubiquitomic characteristics of HCC remain poorly understood. We aimed to reveal the ubiquitomic characteristics of HCC and provide clinical feature biomarkers of the aggressive HCC that may be used for diagnosis or therapy in the clinic. APPROACH AND RESULTS: The comprehensive proteomic, phosphoproteomic, and ubiquitomic analyses were performed on tumors and adjacent normal liver tissues from 85 patients with HCC. HCCs displayed overexpression of drugable targets CBR1-S151 and CPNE1-S55. COL4A1, LAMC1, and LAMA4 were highly expressed in the disease free survival-poor patients. Phosphoproteomic and ubiquitomic features of HCC revealed cross talk in metabolism and metastasis. Ubiquitomics predicted diverse prognosis and clarified HCC subtype-specific proteomic signatures. Expression of biomarkers TUBA1A, BHMT2, BHMT, and ACY1 exhibited differential ubiquitination levels and displayed high prognostic risk scores, suggesting that targeting these proteins or their modified forms may be beneficial for future clinical treatment. We validated that TUBA1A K370 deubiquitination drove severe HCC and labeled an aggressive subtype of HCCs. TUBA1A K370 deubiquitination was at least partly attributed to protein kinase B-mediated USP14 activation in HCC. Notably, targeting AKT-USP14-TUBA1A complex promoted TUBA1A degradation and blocked liver tumorigenesis in vivo. CONCLUSIONS: This study expands our knowledge of ubiquitomic signatures, biomarkers, and potential therapeutic targets in HCC.

Humans↗

PubMed2024

The secreted micropeptide C4orf48 enhances renal fibrosis via an RNA-binding mechanism.

Renal interstitial fibrosis is an important mechanism in the progression of chronic kidney disease (CKD) to end-stage kidney disease. However, we lack specific treatments to slow or halt renal fibrosis. Ribosome profiling identified upregulation of a secreted micropeptide, C4orf48 (Cf48), in mouse diabetic nephropathy. Cf48 RNA and protein levels were upregulated in tubular epithelial cells in human and experimental CKD. Serum Cf48 levels were increased in human CKD and correlated with loss of kidney function, increasing CKD stage, and the degree of active interstitial fibrosis. Cf48 overexpression in mice accelerated renal fibrosis, while Cf48 gene deletion or knockdown by antisense oligonucleotides significantly reduced renal fibrosis in CKD models. In vitro, recombinant Cf48 (rCf48) enhanced TGF-β1-induced fibrotic responses in renal fibroblasts and epithelial cells independently of Smad3 phosphorylation. Cellular uptake of Cf48 and its profibrotic response in fibroblasts operated via the transferrin receptor. RNA immunoprecipitation-sequencing identified Cf48 binding to mRNA of genes involved in the fibrotic response, including Serpine1, Acta2, Ccn2, and Col4a1. rCf48 binds to the 3'UTR of Serpine1 and increases mRNA half-life. We identify the secreted Cf48 micropeptide as a potential enhancer of renal fibrosis that operates as an RNA-binding peptide to promote the production of extracellular matrix.

Animals↗

PubMed2024

Disassembly of the TRIM56-ATR complex promotes cytoDNA/cGAS/STING axis-dependent intervertebral disc inflammatory degeneration.

As the leading cause of disability worldwide, low back pain (LBP) is recognized as a pivotal socioeconomic challenge to the aging population and is largely attributed to intervertebral disc degeneration (IVDD). Elastic nucleus pulposus (NP) tissue is essential for the maintenance of IVD structural and functional integrity. The accumulation of senescent NP cells with an inflammatory hypersecretory phenotype due to aging and other damaging factors is a distinctive hallmark of IVDD initiation and progression. In this study, we reveal a mechanism of IVDD progression in which aberrant genomic DNA damage promoted NP cell inflammatory senescence via activation of the cyclic GMP-AMP synthase/stimulator of IFN genes (cGAS/STING) axis but not of absent in melanoma 2 (AIM2) inflammasome assembly. Ataxia-telangiectasia-mutated and Rad3-related protein (ATR) deficiency destroyed genomic integrity and led to cytosolic mislocalization of genomic DNA, which acted as a powerful driver of cGAS/STING axis-dependent inflammatory phenotype acquisition during NP cell senescence. Mechanistically, disassembly of the ATR-tripartite motif-containing 56 (ATR-TRIM56) complex with the enzymatic liberation of ubiquitin-specific peptidase 5 (USP5) and TRIM25 drove changes in ATR ubiquitination, with ATR switching from K63- to K48-linked modification, c thereby promoting ubiquitin-proteasome-dependent dynamic instability of ATR protein during NP cell senescence progression. Importantly, an engineered extracellular vesicle-based strategy for delivering ATR-overexpressing plasmid cargo efficiently diminished DNA damage-associated NP cell senescence and substantially mitigated IVDD progression, indicating promising targets and effective approaches to ameliorate the chronic pain and disabling effects of IVDD.

Humans↗

PubMed2007

The binding of FKBP23 to BiP modulates BiP's ATPase activity with its PPIase activity.

Peptidyl-prolyl cis-trans-isomerases (PPIases) are enzymes that can cis-trans-isomerize a Xaa-Pro peptide bond. Three families of PPIases are known: cyclophilins, FKBPs, and parvulins. The physiological functions of the PPIases are only poorly understood. In previous work, we reported that the mouse FK506-binding protein 23 (mFKBP23), which comprises an N-terminal PPIase domain and a C-terminal domain with Ca(2+)-binding sites, binds to mBiP in the endoplasmic reticulum (ER) and this binding is affected by the Ca(2+) concentration. In this study, we demonstrate the ability of mFKBP23 to modulate the ATPase activity of BiP, and that the bound mFKBP23, but not the free mFKBP23, can suppress the ATPase activity of mBiP through its PPIase activity.

Adenosine Triphosphatases↗

PubMed2007

Large-scale genome-wide linkage analysis for loci linked to BMD at different skeletal sites in extreme selected sibships.

UNLABELLED: Few genome-wide linkage studies of osteoporosis have been conducted in the Asian population. We performed a genome-wide scan involving 3093 adult siblings with at least one sib-pair extremely concordant or discordant for hip BMD. Our results indicated four genome-wide significant QTLs for BMD. In comparison with 12 previous reported linkage studies, we reveal novel linkage regions that have reaching global significance. INTRODUCTION: The genetic basis for osteoporosis has been firmly established, but efforts to identify genes associated with this complex trait have been incomplete, especially in Asian populations. The purpose of this study was to identify quantitative trait loci (QTLs) for BMD in a Chinese population. MATERIALS AND METHODS: We performed a genome-wide scan involving 3093 siblings 25-64 years of age from 941 families, with at least one sib-pair extreme concordant or discordant for total hip BMD from a large community-based cohort (n = 23,327) in Anhui, China. Linkage analysis was performed on BMD residuals adjusted for age, height, weight, occupation, cigarette smoking, physical activity, and alcohol consumption using the revised Haseman-Elston regression-based linkage model. RESULTS: Our results revealed significant QTLs on chromosome 7p21.2 for femoral neck BMD (LOD = 3.68) and on chromosome 2q24.3 for total hip BMD (LOD = 3.65). Suggestive linkage regions were found to overlap among different skeletal sites on chromosomes 2q, 7p, and 16q. Sex-specific linkage analysis further revealed a significant QTL for lumbar spine BMD on chromosome 13q21.1 (LOD = 3.62) in women only. When performing multivariate linkage analysis by combining BMDs at four skeletal sites (i.e., whole body, total hip, femoral neck, and lumbar spine BMD), an additional significant QTL was found at chromosome 5q21.2 (LOD = 4.56). None of these significant QTLs found in our study overlapped with major QTLs reported by other studies. CONCLUSIONS: This study reveals four novel QTLs in a Chinese population and suggests that BMD at different skeletal sites may also share common genetic determinants.

Asian People↗

PubMed2006

PIDD: database for Protein Inter-atomic Distance Distributions.

Protein Inter-atomic Distance Distributions (PIDD) is a dedicated database and structural bio-informatics system for distance based protein modeling. The database is developed to host and analyze the statistical data for protein inter-atomic distances based on their distributions in databases of known protein structures such as in the Protein Data Bank (PDB). PIDD is capable of generating, caching, and displaying the statistical distributions of the distances of various types and ranges. The collected information can be used to extract geometric restraints or mean-force potentials for protein structure determination including nuclear magnetic resonance structure determination and comparative model refinement. PIDD is supported with a friendly designed web interface so that users can easily specify the distance types and ranges, and retrieve, visualize or download the distributions of the distances as they desire. PIDD is freely accessible at http://www.math.iastate.edu/pidd.

Databases, Protein↗

PubMed2006

Development of high-specificity antibodies against renal urate transporters using genetic immunization.

Recently three proteins, playing central roles in the bidirectional transport of urate in renal proximal tubules, were identified: two members of the organic anion transporter (OAT) family, OAT1 and OAT3, and a protein that designated renal urate-anion exchanger (URAT1). Antibodies against these transporters are very important for investigating their expressions and functions. With the cytokine gene as a molecular adjuvant, genetic immunization-based antibody production offers several advantages including high specificity and high recognition to the native protein compared with current methods. We fused high antigenicity fragments of the three transporters to the plasmids pBQAP-TT containing T-cell epitopes and flanking regions from tetanus toxin, respectively. Gene gun immunization with these recombinant plasmids and two other adjuvant plasmids, which express granulocyte/ macrophage colony-stimulating factor and FMS-like tyrosine kinase 3 ligand, induced high level immunoglobulin G antibodies, respectively. The native corresponding proteins of URAT1, OAT1 and OAT3, in human kidney can be recognized by their specific antibodies, respectively, with Western blot analysis and immunohistochemistry. Besides, URAT1 expression in Xenopus oocytes can also be recognized by its corresponding antibody with immuno-fluorescence. The successful production of the antibodies has provided an important tool for the study of UA transporters.

Animals↗

PubMed2006

Selective Androgen Receptor Modulator (SARM) treatment prevents bone loss and reduces body fat in ovariectomized rats.

PURPOSE: This study was conducted to examine the bone and body composition effects of S-4, an aryl-propionamide derived Selective Androgen Receptor Modulator (SARM) in an ovariectomy induced model of accelerated bone loss. METHODS: One hundred twenty female Sprague-Dawley rats aged to twenty-three weeks were randomly assigned to twelve treatment groups. Drug treatment was initiated immediately following ovariectomy and continued for one hundred twenty days. Whole body bone mineral density (BMD), body composition, and lumbar vertebrae BMD were measured by dual energy x-ray absorptiometry. More stringent regional pQCT and biomechanical strength testing was performed on excised femurs. RESULTS: We found that S-4 treatment maintained whole body and trabecular BMD, cortical content, and increased bone strength while decreasing body fat in these animals. CONCLUSIONS: The data presented herein show the protective skeletal effects of S-4. Our previous reports have shown the tissue selectivity and muscle anabolic activity of S-4. Together these data suggest that S-4 could reduce the incidence of fracture via two different mechanisms (i.e., via direct effects in bone and reducing the incidence of falls through increased muscle strength). This approach to fracture reduction would be advantageous over current therapies in these patients which are primarily antiresorptive in nature.

Absorptiometry, Photon↗

PubMed2006

Flavopiridol administered using a pharmacologically derived schedule is associated with marked clinical efficacy in refractory, genetically high-risk chronic lymphocytic leukemia.

Despite promising preclinical studies with the cyclin-dependent kinase inhibitor flavopiridol in chronic lymphocytic leukemia (CLL) and other diseases, previous clinical trials with this agent have been disappointing. The discovery of differential protein binding of flavopiridol in human and bovine serum contributed to an effective pharmacokinetic-derived schedule of administration of this agent. On the basis of pharmacokinetic modeling using our in vitro results and data from a previous trial, we initiated a phase 1 study using a 30-minute loading dose followed by 4 hours of infusion administered weekly for 4 of 6 weeks in patients with refractory CLL. A group of 42 patients were enrolled on 3 cohorts (cohort 1, 30 mg/m2 loading dose followed by 30 mg/m2 4-hour infusion; cohort 2, 40 mg/m2 loading dose followed by 40 mg/m2 4-hour infusion; and cohort 3, cohort 1 dose for treatments 1 to 4, then a 30 mg/m2 loading dose followed by a 50 mg/m2 4-hour infusion). The dose-limiting toxicity using this novel schedule was hyperacute tumor lysis syndrome. Aggressive prophylaxis and exclusion of patients with leukocyte counts greater than 200x10(9)/L have made this drug safe to administer at the cohort 3 dose. Of the 42 patients treated, 19 (45%) achieved a partial response with a median response duration that exceeds 12 months. Responses were noted in patients with genetically high-risk disease, including 5 (42%) of 12 patients with del(17p13.1) and 13 (72%) of 18 patients with del(11q22.3). Flavopiridol administered using this novel schedule has significant clinical activity in refractory CLL. Patients with bulky disease and high-risk genetic features have achieved durable responses, thereby justifying further study of flavopiridol in CLL and other diseases.

Adult↗

PubMed2006

Direct catalytic route to superhydrophobic polyethylene films.

Polyethylene films grow on a flat silica surface modified by the bis(imino)pyridyl iron(II) catalyst during ethylene polymerization in toluene solvent. The resulting films show superhydrophobic properties. Advancing water contact angle as high as 169 degrees and sliding angles as low as 2 degrees are obtained on these films. SEM images reveal special surface structures of these films containing micrometer-sized islands, submicrometer particles on the islands, and stress nanofibers between the islands, which render superhydrophobicity to the polyethylene surfaces. After the submicrometer particles and stress nanofibers are removed by annealing, the superhydrophobic properties of the polymer films disappear.

Catalysis↗

PubMed2006

Do single-electron lithium bonds exist? Prediction and characterization of the H3C...Li-Y (Y=H, F, OH, CN, NC, and CCH) complexes.

A new kind of single-electron lithium bonding complexes H(3)C...LiY (Y=H, F, OH, CN, NC, and CCH) was predicted and characterized in the present paper. Their geometries (C(3v)) with all real harmonic vibrational frequencies were obtained at the MP2/aug-cc-pVTZ level. For each H(3)C...LiY complex, single-electron Li bond is formed between the unpaired electron of CH(3) radical and positively charged Li atom of LiY molecule. Due to the formation of the single-electron Li bond, the C-H bonds of the CH(3) radical bend opposite to the LiY molecule and the Li-Y bond elongates. Abnormally, the three H(3)C...LiY (Y=CN, NC, and CCH) complexes exhibit blueshifted Li-Y stretching frequencies along with the elongated Li-Y bonds. Natural bond orbital analyses suggest ca. 0.02 electron transfer from the methyl radical (CH(3)) to the LiY moiety. In the single occupied molecular orbitals of the H(3)C...LiY complexes, it is also seen that the electron could of the CH(3) radical approaches the Li atom. The single-electron Li bond energies are 5.20-6.94 kcal/mol for the H(3)C...LiY complexes at the CCSD(T)aug-cc-pVDZ+BF (bond functions) level with counterpoise procedure. By comparisons with some related systems, it is concluded that the single-electron Li bonds are stronger than single-electron H bonds, and weaker than conventional Li bonds and pi-Li bonds.

Biophysics↗

PubMed2006

Effect of the complexant shape on the large first hyperpolarizability of alkalides Li+(NH3)4M-.

The effect of complexant shape effect on the first hyperpolarizability beta(0) of alkalides Li(+)(NH(3))(4)M(-) (M=Li, Na, K) was explored. At the MP2/6-311++G level, Li(+)(NH(3))(4)M(-) (M=Li, Na, K) have considerable beta(0) values due to excess electrons from chemical doping and charge transfer. By comparison with the alkalides Li(+)(calix[4]pyrrole)M(-), a complexant shape effect in Li(+)(NH(3))(4)M(-) is detected. The beta(0) values of Li(+)(NH(3))(4)M(-) with the "smaller", inorganic, T(d)-symmetric (NH(3))(4) complexant are more than four times larger than those of Li(+)(calix[4]pyrrole)M(-) with the "larger", organic C(4v)-symmetric calix[4]pyrrole complexant. The ratios of the beta(0) values of Li(+)(NH(3))(4)M(-) and Li(+)(calix[4]pyrrole)M(-) are 6.57 (M=Li ), 6.55 (M=Na), and 5.17 (M=K). In the Li(+)(NH(3))(4)M(-) systems, the NBO charge and oscillator strength are found to monotonically depend on the atomic number of the alkali metal anion. The order of the NBO charges of the alkali anions M(-) is -0.667 (M=Li )>-0.644 (M=Na)>-0.514 (M=K), while the order of the oscillator strengths in the crucial transition is 0.351 (M=Li )<0.360 (M=Na)<0.467 (M=K). This indicates that complexant shape effects are strong, and consequently the beta(0) values of Li(+)(NH(3))(4)M(-) are found to be beta(0)=70 295 (M=Li )<96 780 (M=Na)<185 805 a.u. (M=K). This work reveals that the use of a high-symmetry complexant is an important factor that should be taken into account when enhancing the first hyperpolarizability of alkalides by chemical doping.

Journal Article↗