In Situ TEM Study of the Degradation of PbSe Nanocrystals in Air

PbSe nanocrystals have attracted widespread attention due to a variety of potential applications. However, the practical utility of these nanocrystals has been hindered by their poor air stability, which induces undesired changes in the optical and electronic properties. An understanding of the degradation of PbSe nanocrystals when they are exposed to air is critical for improving the stability and enhancing their applications. Here, we use in situ transmission electron microscopy (TEM) with an environmental cell connected to air to study PbSe nanocrystal degradation triggered by air exposure. We have also conducted a series of complementary studies, including in situ environmental TEM study of PbSe nanocrystals exposed to pure oxygen and PbSe nanocrystals in H2O using a liquid cell, and ex situ experiments, such as O2 plasma treatment and thermal heating of PbSe nanocrystals under different air exposure. Our in situ observations reveal that when PbSe nanocrystals are exposed to air (or oxygen) under electron beam irradiation, they experience a series of changes, including shape evolution of individual nanocrystals with the cuboid intermediates, coalescence between nanocrystals, and formation of PbSe thin films through drastic solid-state fusion. Further studies show that the PbSe thin films transform into an amorphous Pb rich phase or eventually pure Pb, which suggest that Se reacts with oxygen and can be evaporated under electron beam illumination. These various in situ and ex situ experimental results indicate that PbSe nanocrystal degradation in air is initiated by the dissociation and removal of ligands from the PbSe nanocrystal surface

Co-sensitization and cross-reactivity of Blomia tropicalis with two Dermatophagoides species in Guangzhou, China

Around 85.50% of patients were sensitized to Der p, 85.37% of patients were sensitized to Der f, and 71.54% of patients were sensitized to Blo t. Further, 70.14% of patients were co-sensitized to Blo t, Der p, and Der f, and only seven patients were sensitized solely to Blo t. With increasing sIgE levels for Blo t, the positive rates of severe-level (class 5-6) co-sensitization to Der p or Der f significantly increased. Blo t was moderately associated with Der p and Der f, with correlation coefficients of 0.6998 and 0.6782, respectively. Der p and Der f inhibited IgE binding to Blo t more strongly than Blo t inhibited IgE binding to Der p or Der f in the patient groups CBlo t  < CDer p and CBlo t  < CDer f .Open Project of State Key Laboratory of Respiratory Disease [SKLRD-OP-201803, SKLRD-OP-201809]; Science and Technology Innovation Committee Project of Guangzhou [201831802]; Bureau of traditional Chinese Medicine Scientific Research Project of Guangdong [20192048]; National Natural Science Foundation of China [81601394, 81802076, 81871736]Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Relationships of beans intake with chronic kidney disease in rural adults: A large-scale cross-sectional study

Background and aimsDietary factors play an important role in the development of chronic kidney disease (CKD). However, evidence on the relationship of beans consumption with CKD remains limited and inconclusive, especially in the middle-and low-income populations. The current study aimed to investigate the relationships of beans intake with indicators of kidney injury and CKD prevalence in rural adults.MethodsA total of 20,733 rural adults from the Henan Rural Cohort Study in 2018–2022 were included. The total beans intake was collected using a validated food frequency questionnaire. Indicators of kidney injury and CKD was determined by the estimated glomerular filtration rate and the urinary albumin to creatinine ratio. Generalized linear regression and logistic regression models were applied to estimate the relationship of beans intake with continuous and dichotomized indicators of renal function, respectively.ResultsOf the 20,733 participants, 2,676 (12.91%) subjects were identified as CKD patients. After adjusting for potential confounders, participants in the higher quartiles of beans intake had a lower prevalence of CKD (odds ratio and 95% confidence interval, OR (95%CI); Q2: 0.968(0.866–1.082); Q3: 0.836(0.744–0.939); Q4: 0.854(0.751–0.970)) and albuminuria (Q2: 0.982(0.875–1.102); Q3: 0.846(0.750–0.954); Q4: 0.852 (0.746–0.973)), compared with the Q1. Per 50 g/day increment in beans intake was significantly associated with a 5 and 4% decreased prevalence of albuminuria and CKD, respectively. These inverse relationships were also significant in the subgroups of men, elder, and high-income participants (p &lt; 0.05).ConclusionDietary beans intake was inversely associated with the prevalence of albuminuria and CKD in rural adults, suggesting that promoting soy food intake might help reduce the occurrence of CKD in rural adults

LEGO-Prover: Neural Theorem Proving with Growing Libraries

Despite the success of large language models (LLMs), the task of theorem proving still remains one of the hardest reasoning tasks that is far from being fully solved. Prior methods using language models have demonstrated promising results, but they still struggle to prove even middle school level theorems. One common limitation of these methods is that they assume a fixed theorem library during the whole theorem proving process. However, as we all know, creating new useful theorems or even new theories is not only helpful but crucial and necessary for advancing mathematics and proving harder and deeper results. In this work, we present LEGO-Prover, which employs a growing skill library containing verified lemmas as skills to augment the capability of LLMs used in theorem proving. By constructing the proof modularly, LEGO-Prover enables LLMs to utilize existing skills retrieved from the library and to create new skills during the proving process. These skills are further evolved (by prompting an LLM) to enrich the library on another scale. Modular and reusable skills are constantly added to the library to enable tackling increasingly intricate mathematical problems. Moreover, the learned library further bridges the gap between human proofs and formal proofs by making it easier to impute missing steps. LEGO-Prover advances the state-of-the-art pass rate on miniF2F-valid (48.0% to 57.0%) and miniF2F-test (45.5% to 47.1%). During the proving process, LEGO-Prover also manages to generate over 20,000 skills (theorems/lemmas) and adds them to the growing library. Our ablation study indicates that these newly added skills are indeed helpful for proving theorems, resulting in an improvement from a success rate of 47.1% to 50.4%. We also release our code and all the generated skills

Ectopic lymphoid tissues support local immunoglobulin production in patients with chronic rhinosinusitis with nasal polyps

Background: The contribution of ectopic lymphoid tissues (eLTs) to local immunoglobulin hyperproduction in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) is unclear. Objective: We sought to explore the cellular basis, formation mechanisms, and function of eLTs in patients with CRSwNP. Methods: We graded lymphoid aggregations in sinonasal mucosa and histologically studied their structures. The expression of lymphorganogenic factors and molecules required for immunoglobulin production was measured by using real-time PCR, and their localization was analyzed by means of immunohistochemistry and immunofluorescence. The phenotype of follicular helper T cells was analyzed by performing flow cytometry. Immunoglobulin levels were quantified by using the Bio-Plex assay or ImmunoCAP system. Nasal tissue explants were challenged ex vivo with Dermatophagoides pteronyssinus group 1 (Der p 1), and the expression of I epsilon-C mu and I epsilon-C gamma circle transcripts was detected by using seminested PCR. Results: Increased formation of eLTs with germinal center-like structures was discovered in patients with eosinophilic (20.69%) and noneosinophilic (17.31%) CRSwNP compared with that in patients with chronic rhinosinusitis without nasal polyps (5.66%) and control subjects (3.70%). The presence of eLTs was associated with increased expression of lymphorganogenic and inflammatory chemokines and cytokines, as well as their receptors. The expression of molecules required for immunoglobulin production, generation of follicular helper T cells, and production of IgE in eosinophilic polyps and IgG and IgA in both eosinophilic and noneosinophilic polyps were predominantly upregulated in patients with eLTs. After Der p 1 challenge ex vivo, I epsilon-C mu transcript was detected only in eosinophilic polyps with eLTs but not in polyps without eLTs and noneosinophilic polyps. Conclusion: eLTs might support local immunoglobulin production and therefore significantly contribute to the development of CRSwNP

Evaluation of X-Inactivation Status and Cytogenetic Stability of Human Dermal Fibroblasts after Long-Term Culture

Human primary fibroblasts are a popular type of somatic cells for the production of induced pluripotent stem (iPS) cells. Here we characterized biological properties of primary fibroblasts in terms of cell-growth rate, cytogenetic stability, and the number of inactive X chromosomes during long-term passaging. We produced eight lines of female human dermal fibroblasts (HDFs) and found normal karyotype and expected pattern of X chromosome inactivation (XCI) at low passages (Passage P1-5). However, four out of the eight HDF lines at high passage numbers (≥ P10) exhibited duplicated hallmarks of inactive X chromosome including two punctuate signals of histone H3 lysine 27 trimethylation (H3K27me3) and X inactive-specific transcript (XIST) RNA signals in approximately 8.5–18.5% of the cells. Our data suggest that the copy number of inactive X chromosomes in a subset of female HDF is increased by a two-fold. Consistently, DNA fluorescent in situ hybridization (FISH) identified 3-4 copies of X chromosomes in one nucleus in this subset of cells with two inactive Xs. We conclude that female HDF cultures exhibit a higher risk of genetic anomalies such as carrying an increased number of X chromosomes including both active and inactive X chromosomes at a high passage (≥ P10)

Conformational adaptation of Asian macaque TRIMCyp directs lineage specific antiviral activity

TRIMCyps are anti-retroviral proteins that have arisen independently in New World and Old World primates. All TRIMCyps comprise a CypA domain fused to the tripartite domains of TRIM5α but they have distinct lentiviral specificities, conferring HIV-1 restriction in New World owl monkeys and HIV-2 restriction in Old World rhesus macaques. Here we provide evidence that Asian macaque TRIMCyps have acquired changes that switch restriction specificity between different lentiviral lineages, resulting in species-specific alleles that target different viruses. Structural, thermodynamic and viral restriction analysis suggests that a single mutation in the Cyp domain, R69H, occurred early in macaque TRIMCyp evolution, expanding restriction specificity to the lentiviral lineages found in African green monkeys, sooty mangabeys and chimpanzees. Subsequent mutations have enhanced restriction to particular viruses but at the cost of broad specificity. We reveal how specificity is altered by a scaffold mutation, E143K, that modifies surface electrostatics and propagates conformational changes into the active site. Our results suggest that lentiviruses may have been important pathogens in Asian macaques despite the fact that there are no reported lentiviral infections in current macaque populations