157 research outputs found
Ag-Mg antisite defect induced high thermoelectric performance of Ξ±-MgAgSb
Engineering atomic-scale native point defects has become an attractive strategy to improve the performance of thermoelectric materials. Here, we theoretically predict that Ag-Mg antisite defects as shallow acceptors can be more stable than other intrinsic defects under Mg-poor-Ag/Sb-rich conditions. Under more Mg-rich conditions, Ag vacancy dominates the intrinsic defects. The p-type conduction behavior of experimentally synthesized ΒΏ-MgAgSb mainly comes from Ag vacancies and Ag antisites (Ag on Mg sites), which act as shallow acceptors. Ag-Mg antisite defects significantly increase the thermoelectric performance of ΒΏ-MgAgSb by increasing the number of band valleys near the Fermi level. For Li-doped ΒΏ-MgAgSb, under more Mg-rich conditions, Li will substitute on Ag sites rather than on Mg sites and may achieve high thermoelectric performance. A secondary valence band is revealed in ΒΏ-MgAgSb with 14 conducting carrier pockets
Evaluation and Analysis of Hallucination in Large Vision-Language Models
Large Vision-Language Models (LVLMs) have recently achieved remarkable
success. However, LVLMs are still plagued by the hallucination problem, which
limits the practicality in many scenarios. Hallucination refers to the
information of LVLMs' responses that does not exist in the visual input, which
poses potential risks of substantial consequences. There has been limited work
studying hallucination evaluation in LVLMs. In this paper, we propose
Hallucination Evaluation based on Large Language Models (HaELM), an LLM-based
hallucination evaluation framework. HaELM achieves an approximate 95%
performance comparable to ChatGPT and has additional advantages including low
cost, reproducibility, privacy preservation and local deployment. Leveraging
the HaELM, we evaluate the hallucination in current LVLMs. Furthermore, we
analyze the factors contributing to hallucination in LVLMs and offer helpful
suggestions to mitigate the hallucination problem. Our training data and human
annotation hallucination data will be made public soon.Comment: 11 pages, 5 figure
Variation of cataract surgery costs in four different graded providers of China
<p>Abstract</p> <p>Background</p> <p>China has the largest population of cataract patients in the world. However, the cataract surgery rate per million remains low in China. We carried out a survey on costs of cataract surgery from four different graded providers in China and analyzed differences in cost among these clinics.</p> <p>Methods</p> <p>1,189 patients were recruited for the study in four eye clinics, located in two provinces, Guangdong province in southern China and Hubei province in central China. The average cost of each cataract surgery episode was calculated including cost of intraocular lens, cost of drugs and facility cost. We also collected information on reimbursement and disposable annual income of local residents.</p> <p>Results</p> <p>Mean total cost per cataract intervention of four different providers varied considerably, ranging from US 536 in Jingshan County Hospital. In all providers, except for Jingshan County Hospital, the cost exceeded annual disposable income of local rural residents. As to the proportion of patients with reimbursement, the figure for Union Hospital was only 36%, while for other three clinics it was more than 60%. There was a significant difference between mean reimbursement ratios, with the highest ratio in Zhongshan Ophthalmic Center being 71%.</p> <p>Conclusions</p> <p>Significant differences in costs of cataract surgery were found among the 4 different graded providers. A part of the cost was borne by patients. Proportion of patients with reimbursement and mean reimbursement ratios were higher in economically developed regions than in economically developing regions. Much more financial support should be directed into the rural New Cooperative Medical Scheme to raise the reimbursement ratio in rural China.</p
Atoh8, a bHLH Transcription Factor, Is Required for the Development of Retina and Skeletal Muscle in Zebrafish
Math6/atoh8, a bHLH transcription factor, is thought to be indispensable for early embryonic development and likely has important roles in vertebrate tissue-specific differentiation. However, the function of Atoh8 during early development is not clear because homozygous knockout causes embryonic lethality in mice. We have examined the effects of the atoh8 gene on the differentiation of retina and skeletal muscle during early development in zebrafish.We isolated a Math6 homologue in zebrafish, designated as zebrafish atoh8. Whole -mount in situ hybridization analysis showed that zebrafish atoh8 is dynamically expressed mainly in developing retina and skeletal muscle. Atoh8-MO knock-down resulted in reduced eye size with disorganization of retinal lamination. The reduction of atoh8 function also affected the arrangement of paraxial cells and differentiated muscle fibers during somite morphogenesis.Our results show that Atoh8 is an important regulator for the development of both the retina and skeletal muscles necessary for neural retinal cell and myogenic differentiation during zebrafish embryogenesis
HIV-Infected Former Plasma Donors in Rural Central China: From Infection to Survival Outcomes, 1985β2008
BACKGROUND: The HIV epidemic among former plasma donors (FPDs) in rural Central China in the early-mid 1990s is likely the largest known HIV-infected cohort in the world related to commercial plasma donation but has never been fully described. The objectives of this study are to estimate the timing and geographic spread of HIV infection in this cohort and to demonstrate the impact of antiretroviral therapy on survival outcomes. METHODOLOGY/PRINCIPAL FINDINGS: HIV-infected FPDs were identified using the national HIV epidemiology and treatment databases. Locations of subjects were mapped. Dates of infection and survival were estimated using the midpoint date between initial-final plasma donation dates from 1985-2008 among those with plasma donation windows β€2 years. Among 37,084 FPDs in the two databases, 36,110 were included. 95% were located in focal areas of Henan Province and adjacent areas of surrounding provinces. Midpoint year between initial-final plasma donation dates was 1994 among FPDs with known donation dates. Median survival from infection to AIDS was 11.8 years and, among those not treated, 1.6 years from AIDS to death. Among those on treatment, 71% were still alive after five years. Using Cox proportional hazard modeling, untreated AIDS patients were 4.9 times (95% confidence interval 4.6-5.2) more likely to die than those on treatment. CONCLUSIONS/SIGNIFICANCE: The epidemic of HIV-infected FPD in China was not widespread throughout China but rather was centered in Henan Province and the adjacent areas of surrounding provinces. Even in these areas, infections were concentrated in focal locations. Overall, HIV infections in this cohort peaked in 1994, with median survival of 13.4 years from infection to death among those not treated. Among AIDS patients on treatment, 71% were still alive after five years
A Systematic Analysis on DNA Methylation and the Expression of Both mRNA and microRNA in Bladder Cancer
Background: DNA methylation aberration and microRNA (miRNA) deregulation have been observed in many types of cancers. A systematic study of methylome and transcriptome in bladder urothelial carcinoma has never been reported. Methodology/Principal Findings: The DNA methylation was profiled by modified methylation-specific digital karyotyping (MMSDK) and the expression of mRNAs and miRNAs was analyzed by digital gene expression (DGE) sequencing in tumors and matched normal adjacent tissues obtained from 9 bladder urothelial carcinoma patients. We found that a set of significantly enriched pathways disrupted in bladder urothelial carcinoma primarily related to "neurogenesis" and "cell differentiation" by integrated analysis of -omics data. Furthermore, we identified an intriguing collection of cancer-related genes that were deregulated at the levels of DNA methylation and mRNA expression, and we validated several of these genes (HIC1, SLIT2, RASAL1, and KRT17) by Bisulfite Sequencing PCR and Reverse Transcription qPCR in a panel of 33 bladder cancer samples. Conclusions/Significance: We characterized the profiles between methylome and transcriptome in bladder urothelial carcinoma, identified a set of significantly enriched key pathways, and screened four aberrantly methylated and expressed genes. Conclusively, our findings shed light on a new avenue for basic bladder cancer research
Long-term trends of chemical characteristics and sources of fine particle in Foshan City, Pearl River Delta: 2008β2014
The water lily genome and the early evolution of flowering plants
Water lilies belong to the angiosperm order Nymphaeales. Amborellales,
Nymphaeales and Austrobaileyales together form the so-called ANA-grade of
angiosperms, which are extant representatives of lineages that diverged the earliest
from the lineage leading to the extant mesangiosperms1β3. Here we report the
409-megabase genome sequence of the blue-petal water lily (Nymphaea colorata).
Our phylogenomic analyses support Amborellales and Nymphaeales as successive
sister lineages to all other extant angiosperms. The N. colorata genome and 19 other
water lily transcriptomes reveal a Nymphaealean whole-genome duplication event,
which is shared by Nymphaeaceae and possibly Cabombaceae. Among the genes
retained from this whole-genome duplication are homologues of genes that regulate
flowering transition and flower development. The broad expression of homologues of
floral ABCE genes in N. colorata might support a similarly broadly active ancestral
ABCE model of floral organ determination in early angiosperms. Water lilies have
evolved attractive floral scents and colours, which are features shared with
mesangiosperms, and we identified their putative biosynthetic genes in N. colorata.
The chemical compounds and biosynthetic genes behind floral scents suggest that
they have evolved in parallel to those in mesangiosperms. Because of its unique
phylogenetic position, the N. colorata genome sheds light on the early evolution of
angiosperms.Supplementary Tables: This file contains Supplementary Tables 1-21.National Natural Science Foundation of China, the open funds of the State Key Laboratory of Crop Genetics and Germplasm Enhancement (ZW201909) and State Key Laboratory of Tree Genetics and Breeding, the Fujian provincial government in China, the European Union Seventh Framework Programme (FP7/2007-2013) under European Research Council Advanced Grant Agreement and the Special Research Fund of Ghent University.http://www.nature.com/naturecommunicationsam2021BiochemistryGeneticsMicrobiology and Plant Patholog
PD-L1 Exon 3 Is a Hidden Switch of Its Expression and Function in Oral Cancer Cells
The interaction between programmed cell death 1 ligand 1 (PD-L1) and programmed cell death protein 1 (PD-1) protects tumor cells from immune surveillance. PD-L1 exon 3 is a potential alternative exon and encodes an Ig variable (IgV) domain. Here, we found that a lack of exon 3 leads to the significant loss of cellular membrane locations and the dramatically reduced protein expression of PD-L1, indicating that PD-L1 exon 3 is essential for its protein expression and translocation to the cell membrane. Notably, oral cancer cells show almost no exon 3 skipping to ensure the expression of the full-length, functional PD-L1 protein. We discovered two key exonic splicing enhancers (ESEs) for exon 3 inclusion. Two efficient antisense oligonucleotides (ASOs) were identified to block these two ESEs, which can significantly trigger exon 3 skipping and decrease the production of full-length, functional PD-L1 on the surface of cancer cells. Treatment of oral cancer cells with these ASOs significantly enhanced immune cellsβ suppression of cancer cell proliferation. Surprisingly, these two ASOs also significantly inhibited cell growth and induced cell pyroptosis in oral cancer cells. Altogether, the results of our study demonstrate the pivotal roles of exon 3 in PD-L1 expression and provide a novel anti-PD-L1 method
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