Boosting Conversational Question Answering with Fine-Grained Retrieval-Augmentation and Self-Check

Retrieval-Augmented Generation (RAG) aims to generate more reliable and accurate responses, by augmenting large language models (LLMs) with the external vast and dynamic knowledge. Most previous work focuses on using RAG for single-round question answering, while how to adapt RAG to the complex conversational setting wherein the question is interdependent on the preceding context is not well studied. In this paper, we propose a conversation-level RAG approach, which incorporates fine-grained retrieval augmentation and self-check for conversational question answering (CQA). In particular, our approach consists of three components, namely conversational question refiner, fine-grained retriever and self-check based response generator, which work collaboratively for question understanding and relevant information acquisition in conversational settings. Extensive experiments demonstrate the great advantages of our approach over the state-of-the-art baselines. Moreover, we also release a Chinese CQA dataset with new features including reformulated question, extracted keyword, retrieved paragraphs and their helpfulness, which facilitates further researches in RAG enhanced CQA

A novel approach for denoising electrocardiogram signals to detect cardiovascular diseases using an efficient hybrid scheme

BackgroundElectrocardiogram (ECG) signals are inevitably contaminated with various kinds of noises during acquisition and transmission. The presence of noises may produce the inappropriate information on cardiac health, thereby preventing specialists from making correct analysis.MethodsIn this paper, an efficient strategy is proposed to denoise ECG signals, which employs a time-frequency framework based on S-transform (ST) and combines bi-dimensional empirical mode decomposition (BEMD) and non-local means (NLM). In the method, the ST maps an ECG signal into a subspace in the time frequency domain, then the BEMD decomposes the ST-based time-frequency representation (TFR) into a series of sub-TFRs at different scales, finally the NLM removes noise and restores ECG signal characteristics based on structural self-similarity.ResultsThe proposed method is validated using numerous ECG signals from the MIT-BIH arrhythmia database, and several different types of noises with varying signal-to-noise (SNR) are taken into account. The experimental results show that the proposed technique is superior to the existing wavelet based approach and NLM filtering, with the higher SNR and structure similarity index measure (SSIM), the lower root mean squared error (RMSE) and percent root mean square difference (PRD).ConclusionsThe proposed method not only significantly suppresses the noise presented in ECG signals, but also preserves the characteristics of ECG signals better, thus, it is more suitable for ECG signals processing

Ultra-compact lithium niobate photonic chip for high-capacity and energy-efficient wavelength-division-multiplexing transmitters

Recently, high-performance thin-film lithium niobate optical modulators have emerged that, together with advanced multiplexing technologies, are highly expected to satisfy the ever-growing demand for high-capacity optical interconnects utilizing multiple channels. Accordingly, in this study, a compact lithium-niobate-on-insulator (LNOI) photonic chip was adopted to establish four-channel wavelength-division-multiplexing (WDM) transmitters, comprising four optical modulators based on ultracompact 2 × 2 Fabry-Perot cavities and a four-channel WDM filter based on multimode waveguide gratings. The fabricated chip with four wavelength channels has a total footprint as compact as 0.3 × 2.8 mm2, and exhibits an excess loss of ~0.8 dB as well as low inter-channel crosstalk of < –22 dB. Using this LNOI photonic chip, high-capacity data transmissions of 320 Gbps (4 × 80 Gbps) on-off-keying signals and 400 Gbps (4 × 100 Gbps) four-level pulse amplitude signals were successfully realized with the ultra-low power consumption of 11.9 fJ/bit

Case report of a Li-Fraumeni syndrome-like phenotype with a de novo mutation in <i>CHEK2</i>

BACKGROUND: Cases of multiple tumors are rarely reported in China. In our study, a 57-year-old female patient had concurrent squamous cell carcinoma, mucoepidermoid carcinoma, brain cancer, bone cancer, and thyroid cancer, which has rarely been reported to date. METHODS: To determine the relationship among these multiple cancers, available DNA samples from the thyroid, lung, and skin tumors and from normal thyroid tissue were sequenced using whole exome sequencing. RESULTS: The notable discrepancies of somatic mutations among the 3 tumor tissues indicated that they arose independently, rather than metastasizing from 1 tumor. A novel deleterious germline mutation (chr22:29091846, G->A, p.H371Y) was identified in CHEK2, a Li–Fraumeni syndrome causal gene. Examining the status of this novel mutation in the patient's healthy siblings revealed its de novo origin. CONCLUSION: Our study reports the first case of Li–Fraumeni syndrome-like in Chinese patients and demonstrates the important contribution of de novo mutations in this type of rare disease

Detection and analysis of human papillomavirus (HPV) DNA in breast cancer patients by an effective method of HPV capture

Despite an increase in the number of molecular epidemiological studies conducted in recent years to evaluate the association between human papillomavirus (HPV) and the risk of breast carcinoma, these studies remain inconclusive. Here we aim to detect HPV DNA in various tissues from patients with breast carcinoma using the method of HPV capture combined with massive paralleled sequencing (MPS). To validate the confidence of our methods, 15 cervical cancer samples were tested by PCR and the new method. Results showed that there was 100% consistence between the two methods.DNA from peripheral blood, tumor tissue, adjacent lymph nodes and adjacent normal tissue were collected from seven malignant breast cancer patients, and HPV type 16(HPV16) was detected in 1/7, 1/7, 1/7and 1/7 of patients respectively. Peripheral blood, tumor tissue and adjacent normal tissue were also collected from two patients with benign breast tumor, and 1/2, 2/2 and 2/2 was detected to have HPV16 DNA respectively. MPS metrics including mapping ratio, coverage, depth and SNVs were provided to characterize HPV in samples. The average coverage was 69% and 61.2% for malignant and benign samples respectively. 126 SNVs were identified in all 9 samples. The maximum number of SNVs was located in the gene of E2 and E4 among all samples. Our study not only provided an efficient method to capture HPV DNA, but detected the SNVS, coverage, SNV type and depth. The finding has provided further clue of association between HPV16 and breast cancer

Tracking the mind’s eyes: Spatiotemporal Dynamics of Domain-General and Domain-Specific Visual Mental Imagery

When we relive our memories, enjoy a novel, create a painting, or predict whether our car will fit in a parking spot, we use our “Mind’s Eye” to engage in Visual Mental Imagery (VMI). The current consensus is that VMI depends crucially on early visual areas. By contrast, longstanding evidence from neurological patients demonstrates that vivid VMI is possible even with no contribution from these areas. Instead, VMI can be impaired by left temporal damage. In a meta-analysis of neuroimaging studies, we discovered VMI-associated activity, not only in fronto-parietal areas, where it had been detected by earlier studies, but also in a previously undescribed functional region of the left ventrotemporal cortex, which we have called the Fusiform Imagery Node (FIN). The role of this region in VMI was apparent in a ultra-high field 7T fMRI that showed activation in left-hemisphere fronto-parietal areas, the relevant domain-preferring areas in the ventral temporal cortex partly overlapping with the perceptual domain-preferring areas, and the domain-general FIN. These recent results make this the ideal moment to build a new neurocognitive model of voluntary VMI, reliant on a heterarchical neural architecture that mixes domain-general and domain-specific mechanisms. In this study, we will identify the functional role of cortical nodes in VMI-related networks using MEG in neurotypical participants, and we will ascertain the temporal dynamics of the relevant neural processes associated with domain-specific VMI. Results will be compared and contrasted against predictions from competing models of visual mental imagery, providing new hypotheses for the mechanisms underlying this function, and building a bridge to broader theories of conscious awareness

Diagnosis and Prognosis of Retroperitoneal Liposarcoma: A Single Asian Center Cohort of 57 Cases

Background. Liposarcoma is a soft tissue malignancy, commonly observed in the extremities. However, retroperitoneal liposarcoma is seldom reported and its diagnosis is frequently neglected. This study aims to present the clinical characteristics, diagnosis, and prognosis of five liposarcoma subtypes and report our experience of patient treatment. Methods. We conducted a single-center noninterventional retrospective study of 57 retroperitoneal liposarcoma patients admitted to Peking Union Medical College Hospital (PUMCH, Beijing, China) between July 2011 and December 2019. We collected and analyzed their demographic, clinical, imaging, histological, therapeutic, and prognostic data over a mean 4.5-year follow-up period. Results. Twenty-five (44%) patients were asymptomatic prior to diagnosis, with abdominal distension as the chief complaint in 18 (32%) patients and abdominal pain observed in 16 (28%) patients. Masses were evaluated by computed tomography (n = 48, 84%) or ultrasound (n = 25, 44%). Laparotomy (n = 52, 91%) was the dominant therapeutic modality rather than laparoscopy (n = 5, 9%). All patients were treated with R0 resection except two patients who underwent R2 resection. We conducted regular follow-ups every six months after surgery for a mean duration of 4.5 years. Recurrence was experienced by 14 (25%) patients and a further 9 (16%) died during follow-up. Conclusions. Abdominal distension and pain are chief complaints with liposarcoma. As the extremities are the main liposarcomas locations, the diagnosis of retroperitoneal liposarcoma is usually neglected. Since half of the patients are asymptomatic, timely diagnosis and treatment are highly dependent on regular ultrasound and computed tomography imaging. R0 resection is the key to retroperitoneal liposarcoma treatment. In comparison, patients who underwent R2 resection, which is considered a palliative treatment, had bad prognoses. Large, symptomatic dedifferentiated, and pleomorphic liposarcomas are more likely to have poor prognoses, while the prognosis for well-differentiated or myxoid liposarcoma is relatively good

Cu2Se-based injectable hydrogels for synergistic photothermal/gas therapy of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) produces malignant tumours in the oral cavity and adjacent anatomical structures, ranking sixth among the 11 most common malignant tumours in the body. The poor surgical outcomes for OSCC have led to increasing interest in nanomedicines. Major challenges with concentration-dependent therapies include the effective and precise delivery of gases to the lesion and combination with other therapies to achieve precise treatment. Herein, novel Cu2Se nanosheets (Cu2Se NSs) were ingeniously synthesized and enveloped with a thermosensitive nitric oxide (NO) supplier (sodium nitroprusside dihydrate, SNP) within a sodium alginate (ALG) hydrogel matrix to effectively eradicate tumours by combining photothermal therapy (PTT) and gas therapy (GT). The Cu2Se NSs reduced the glutathione (GSH) present in high concentrations to glutathione disulfide (GSSG), effectively killing squamous cell carcinoma cells under 1064 nm laser irradiation. Moreover, the Cu2Se NS hydrogel wrapped with SNP exhibited good NIR-controlled NO release behaviour, thus realizing the combined application of PTT and GT. PTT along with NO release is expected to improve the antitumour effect and provide new solutions for treating OSCC