MILL: Mutual Verification with Large Language Models for Zero-Shot Query Expansion

Query expansion is a commonly-used technique in many search systems to better represent users' information needs with additional query terms. Existing studies for this task usually propose to expand a query with retrieved or generated contextual documents. However, both types of methods have clear limitations. For retrieval-based methods, the documents retrieved with the original query might not be accurate enough to reveal the search intent, especially when the query is brief or ambiguous. For generation-based methods, existing models can hardly be trained or aligned on a particular corpus, due to the lack of corpus-specific labeled data. In this paper, we propose a novel Large Language Model (LLM) based mutual verification framework for query expansion, which alleviates the aforementioned limitations. Specifically, we first design a query-query-document generation pipeline, which can effectively leverage the contextual knowledge encoded in LLMs to generate sub-queries and corresponding documents from multiple perspectives. Next, we employ a mutual verification method for both generated and retrieved contextual documents, where 1) retrieved documents are filtered with the external contextual knowledge in generated documents, and 2) generated documents are filtered with the corpus-specific knowledge in retrieved documents. Overall, the proposed method allows retrieved and generated documents to complement each other to finalize a better query expansion. We conduct extensive experiments on three information retrieval datasets, i.e., TREC-DL-2020, TREC-COVID, and MSMARCO. The results demonstrate that our method outperforms other baselines significantly

Stability and drug dissolution evaluation of Qingkailing soft/hard capsules based on multi-component quantification and fingerprint pattern statistical analysis

Purpose: To carry out a post-marketing evaluation of the stability and drug dissolution of Qingkailing soft/hard capsules.Methods: High performance liquid chromatography with diode array detection (HPLC-DAD) method was developed for the determination of three key ingredients (chlorogenic acid, geniposide and baicalin) and fingerprints of QKL soft/hard capsules. Stability tests were carried out based on long-term testing. The drug release profile of Qingkailing soft and hard capsules were studied using semi-bionic incubation experiments.Results: The linearity, precision, stability, repeatability and recovery of HPLC and fingerprint all met the requirements of CFDA. Stability data from long-term studies showed that within 6 months the contents of the three key ingredients in both soft and hard capsules remained > 90 %. However, fingerprint pattern statistical analysis showed that the soft capsule is more stable than the hard capsule. Furthermore, the key ingredients of the hard capsule dissolved much faster (p < 0.05) than from the soft capsule. The level of dissolved drug of hard capsule is about 4 times the rate of soft capsule, after a 4-h incubation in gastric lavage fluid. In intestinal lavage fluid, more than 90 % of chlorogenic acid, geniposide and baicalin of hard capsule were dissolved in 2 h, while the soft capsule displayed a 12 h sustained release. Fingerprint pattern statistical analysis also showed that most of the components of soft capsule dissolved after 8 h.Conclusion: Compared with the hard capsule, Qingkailing soft capsule has certain advantages in stability and drug dissolution, which may affect the biopharmaceutics and the clinical effects of the drug.Keywords: Qingkailing capsule, Chlorogenic acid, Geniposide, Baicalin, Fingerprint, Sustained release, Principal component analysi

Early Exercise Affects Mitochondrial Transcription Factors Expression after Cerebral Ischemia in Rats

Increasing evidence shows that exercise training is neuroprotective after stroke, but the underlying mechanisms are unknown. To clarify this critical issue, the current study investigated the effects of early treadmill exercise on the expression of mitochondrial biogenesis factors. Adult rats were subjected to ischemia induced by middle cerebral artery occlusion followed by reperfusion. Expression of two genes critical for transcriptional regulation of mitochondrial biogenesis, peroxisome proliferator-activated receptor coactivator-1 (PGC-1) and nuclear respiratory factor-1 (NRF-1), were examined by RT-PCR after five days of exercise starting at 24 h after ischemia. Mitochondrial protein cytochrome C oxidase subunit IV (COX IV) was detected by Western blot. Neurological status and cerebral infarct volume were evaluated as indices of brain damage. Treadmill training increased levels of PGC-1 and NRF-1 mRNA, indicating that exercise promotes rehabilitation after ischemia via regulation of mitochondrial biogenesis

Fine-Grained Population Mobility Data-Based Community-Level COVID-19 Prediction Model

Predicting the number of infections in the anti-epidemic process is extremely beneficial to the government in developing anti-epidemic strategies, especially in fine-grained geographic units. Previous works focus on low spatial resolution prediction, e.g., county-level, and preprocess data to the same geographic level, which loses some useful information. In this paper, we propose a fine-grained population mobility data-based model (FGC-COVID) utilizing data of two geographic levels for community-level COVID-19 prediction. We use the population mobility data between Census Block Groups (CBGs), which is a finer-grained geographic level than community, to build the graph and capture the dependencies between CBGs using graph neural networks (GNNs). To mine as finer-grained patterns as possible for prediction, a spatial weighted aggregation module is introduced to aggregate the embeddings of CBGs to community level based on their geographic affiliation and spatial autocorrelation. Extensive experiments on 300 days LA city COVID-19 data indicate our model outperforms existing forecasting models on community-level COVID-19 prediction.Comment: Accepted by Cybernetics and System

BDNF Promotes EGF-Induced Proliferation and Migration of Human Fetal Neural Stem/Progenitor Cells via the PI3K/Akt Pathway

Neurogenesis is a complex process, which contributes to the ability of the adult brain to function normally and adapt to diseases. Epidermal growth factor (EGF) is known to play an important role in neurogenesis; however, the underlying mechanism is still unclear. Here, we hypothesized that brain-derived neurotrophic factor (BDNF) can enhance the effect of EGF on neurogenesis. Using in vitro cell culture of aborted human fetal brain tissues, we investigated proliferation and migration of neural stem/progenitor cells (NSPCs) after treatment with EGF and different concentrations of BDNF. EGF stimulated proliferation and migration of NSPCs, and this effect was significantly enhanced by co-incubation with BDNF. In the NSPCs treated with 50 ng/mL BDNF, BrdU incorporation was significantly increased (from 7.91% to 17.07%), as compared with that in the control. Moreover, the number of migrating cells was at least 2-fold higher than that in the control. Furthermore, phosphorylation of Akt-1 was increased by BDNF treatment, as well. By contrast, the enhancing effect of BDNF on EGF-induced proliferation and migration of NSPCs were abolished by an inhibitor of PI3K, LY294002. These findings suggest that BDNF promotes EGF-induced proliferation and migration of NSPC through the PI3K/Akt pathway, providing significant insights into not only the mechanism underlying EGF-induced neurogenesis but also potential neuronal replacement strategies to treat brain damage

Discovering Traditional Chinese Medicinal Herbs for Neurodegenerative Disorders

In this investigation, candidate traditional Chinese medicinal herbs for 3 neurodegenerative disorders, late-onset Alzheimer's disease, late-onset Parkinson's disease and Huntington disease were evaluated. The susceptibility genes were integrated to reconstruct traditional Chinese medicine-modern medicine network to discover the candidate herbs. For the 3 neurodegenerative disorders, the number of diseaserelated genes were increased from 2 to 16, which are directly associated with ingredients. Many traditional Chinese medicinal herbs associated with the 3 neurodegenerative disorders were identified (false discovery rate Benjamini-Hochberg<0.05). Four herbs for late-onset Alzheimer's disease are related to P-amyloid 1-42 measurement-associated genes BCAM and APOE by ingredients resveratrol and kainic acid. There are 3 herbs correlated to late-onset Parkinson's disease by both ingredient support and modern medicine symptom association evidence. Four traditional Chinese medicinal herbs are related to Huntington disease by ingredients. Available animal experiments in rats indicated that resveratrol could help to clean p-amyloid in brain to treat Alzheimer's disease, probably through targeting LRP1 protein. This study provided a novel way to utilize genetic data to explore traditional Chinese medicinal herbs and a new insight into drug discovery of neurodegenerative disorders

Size Effect of Mesoporous Silica Nanoparticles on Pesticide Loading, Release, and Delivery in Cucumber Plants

Mesoporous silica nanoparticles (MSN) are widely used as pesticide carriers to enhance their effective utilization, since it can promote the solubility and absorption of pesticides by plants. For plants, the particle size of pesticides influences their absorption and efficacy. Herein, is our research work of the size effect of MSN on the loading, release, and delivery behavior of pyraoxystrobin (Pyr) in cucumber plants. The well-ordered Pyr-loaded carbon quantum dots-MSN (Pyr@M) with sizes of 15, 100, and 200 nm were prepared. A comparative study among different particle sizes of Pyr@M was carried out on the aspects of control release performance, loading content, uptake, and transportation performance in cucumber plants. It was found that the loading content increased as the particle size increased. The nanoparticles as carriers increased the solubility of insoluble Pyr, but the nanoparticle size had no clear difference impact on the release rate. The efficiency of the cellular uptake strongly depended on the particle size. The smaller the MSN size, the easier it was to be absorbed and transmitted by cucumber plants. Compared to the free Pyr, the upward transportation rate of Pyr from Pyr@M in plant increased by 3.5 times. These findings provide new theoretical basis to design the MSN pesticide delivery system

Early Exercise Protects against Cerebral Ischemic Injury through Inhibiting Neuron Apoptosis in Cortex in Rats

Early exercise is an effective strategy for stroke treatment, but the underlying mechanism remains poorly understood. Apoptosis plays a critical role after stroke. However, it is unclear whether early exercise inhibits apoptosis after stroke. The present study investigated the effect of early exercise on apoptosis induced by ischemia. Adult SD rats were subjected to transient focal cerebral ischemia by middle cerebral artery occlusion model (MCAO) and were randomly divided into early exercise group, non-exercise group and sham group. Early exercise group received forced treadmill training initiated at 24 h after operation. Fourteen days later, the cell apoptosis were detected by TdT-mediated dUTP-biotin nick-end labeling (TUNEL) and Fluoro-Jade-B staining (F-J-B). Caspase-3, cleaved caspase-3 and Bcl-2 were determined by western blotting. Cerebral infarct volume and motor function were evaluated by cresyl violet staining and foot fault test respectively. The results showed that early exercise decreased the number of apoptotic cells (118.74 ± 6.15 vs. 169.65 ± 8.47, p < 0.05, n = 5), inhibited the expression of caspase-3 and cleaved caspase-3 (p < 0.05, n = 5), and increased the expression of Bcl-2 (p < 0.05, n = 5). These data were consistent with reduced infarct volume and improved motor function. These results suggested that early exercise could provide neuroprotection through inhibiting neuron apoptosis