A spatiotemporal atlas of mouse liver homeostasis and regeneration

The mechanism by which mammalian liver cell responses are coordinated during tissue homeostasis and perturbation is poorly understood, representing a major obstacle in our understanding of many diseases. This knowledge gap is caused by the difficulty involved with studying multiple cell types in different states and locations, particularly when these are transient. We have combined Stereo-seq (spatiotemporal enhanced resolution omics-sequencing) with single-cell transcriptomic profiling of 473,290 cells to generate a high-definition spatiotemporal atlas of mouse liver homeostasis and regeneration at the whole-lobe scale. Our integrative study dissects in detail the molecular gradients controlling liver cell function, systematically defining how gene networks are dynamically modulated through intercellular communication to promote regeneration. Among other important regulators, we identified the transcriptional cofactor TBL1XR1 as a rheostat linking inflammation to Wnt/β-catenin signaling for facilitating hepatocyte proliferation. Our data and analytical pipelines lay the foundation for future high-definition tissue-scale atlases of organ physiology and malfunction.

Protocol for acquiring high-quality fresh mouse lung spatial transcriptomics data

Spatial transcriptomics analysis allows the examination of the biological characteristics and spatial distribution of individual lung cells at a single-cell resolution. However, due to the presence of cavities in the alveoli of the lungs, it is challenging to section them for spatial transcriptomics experiments. Here, we present a protocol for acquiring high-quality fresh mouse lung spatial transcriptomics data. We describe steps for lung perfusion, acquiring frozen slices, collecting cDNA from lung sections, and data analysis. For complete details on the use and execution of this protocol, please refer to Jiang et al.1.

Measurement of the Positive Muon Anomalous Magnetic Moment to 0.20 ppm

We present a new measurement of the positive muon magnetic anomaly, a_{μ}≡(g_{μ}-2)/2, from the Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. We have analyzed more than 4 times the number of positrons from muon decay than in our previous result from 2018 data. The systematic error is reduced by more than a factor of 2 due to better running conditions, a more stable beam, and improved knowledge of the magnetic field weighted by the muon distribution, ω[over ˜]_{p}^{'}, and of the anomalous precession frequency corrected for beam dynamics effects, ω_{a}. From the ratio ω_{a}/ω[over ˜]_{p}^{'}, together with precisely determined external parameters, we determine a_{μ}=116 592 057(25)×10^{-11} (0.21 ppm). Combining this result with our previous result from the 2018 data, we obtain a_{μ}(FNAL)=116 592 055(24)×10^{-11} (0.20 ppm). The new experimental world average is a_{μ}(exp)=116 592 059(22)×10^{-11} (0.19 ppm), which represents a factor of 2 improvement in precision.

The Efficacy of Silver Sulfadiazine (SSD) Dressing Combined with Recombinant Human Epidermal Growth Factor in the Treatment of Third-Grade Radiation Dermatitis: A Randomized Controlled Study

PURPOSE/OBJECTIVE(S)

Radiation dermatitis is the most common complication of radiation therapy for oncology. Studies have shown that approximately 47% patients develop a second-degree or higher radiation skin reaction after radiotherapy. Although skin products that form a surface barrier such as dressings are standard of care in wound care management, they have been poorly reported in the management of radiation dermatitis. Many systemic and topical treatments have been investigated for the prevention and management of radiation dermatitis, however, how to improve this process is still needed. We hypothesize that silver sulfadiazine (SSD) dressings combined with recombinant human epidermal growth factor (EGF) may accelerate wound healing and reduce painful dressing changes.

MATERIALS/METHODS

Sixty patients who received radiotherapy and developed tertiary radiation dermatitis in our department from January 2019 to December 2022 were selected for the study, and were randomly divided into a control group (n = 30) and an observation group (n = 30) in a 1:1 ratio according to the inclusion criteria, both groups were first aseptically cleared with 0.9% sodium chloride injection and uniformly sprayed with recombinant human epidermal growth factor solution. In the control group, a foam dressing was used, while in the observation group, a silver sulfadiazine dressing was used to cover the wound, and in both groups, a double layer of sterile gauze was fixed on the outer layer. Wound healing time and pain level, and secondary observation endpoints were patient quality of life scores (SF-36, including physical function, psychological function, social function, daily activities, all scored on a percentage scale), patient satisfaction, and skin temperature.

RESULTS

The results of the control group vs. the observation group showed: wound healing time (d) of (12±5.08) vs. (8.57±3.11), p = 0.03; NRS pain score of (2.98±1.65) vs. (2.08±1.66), p = 0.04; quality of life assessment showed: psychological aspects (88.25±8.12) vs. 96.34±6.18), p = 0.0413; physical aspects (85.78±5.71) vs. (94.48±4.09), p = 0.0227; environmental aspects (90.15±3.56) vs. (98.09±1.21), p = 0.0137; satisfaction rate 28 (93.33%) vs. 30 (100.00%) , dissatisfaction rate was 2 (6.67%) vs. 0 (0.00%), p = 0.0086; skin temperature (32.08±0.79) vs. (32.14±0.43), no statistically significant difference p>0.05.

CONCLUSION

This randomized preliminary study showed that silver sulfadiazine dressing combined with recombinant human epidermal growth factor was significantly more effective than foam dressing in the treatment of tertiary radiation dermatitis, accelerating wound healing time, reducing patient painful dressing changes, and improving patient satisfaction.

The Effect of Nursing Intervention Based on HFMEA Model on the Prevention of Radiation Dermatitis: A Randomized Controlled Study

PURPOSE/OBJECTIVE(S)

Radiationdermatitis is one of the most common complications in patients received radiotherapy. Previous studies shown that incidence of radiation induced dermatitis (RD) is 95%. HFMEA (Healthcare Failure Mode and Effect Analysis) is a new model of nursing management. Many studies reported that HFMEA could reduce incidence of complications and adverse events, and significantly improve patient satisfaction.

MATERIALS/METHODS

From March 2023 to October 2022, patients received radiotherapy in our center were recruited in this study. Participants were randomly divided into control group (N = 60) and observation group (N = 60) in a ratio of 1:1. Patients in the control group were given routine skin care, health education before radiotherapy and skin care manual during radiotherapy. Based on the standard care, a HFMEA-based nursing intervention was adopted in the observation group by the following methods: Set up HFMEA care team. HFMEA team is composed of head nurses, wound specialist nurses, psychotherapists, etc. The members of the group searched the literature, case analysis and brainstorming to find out the potential failure reasons in every process of nursing radiotherapy patients in the past. Implementation of targeted measures to improve the corresponding: all patients with radiation dermatitis baseline assessment, focus on high-risk patients to shift, regular guidance medication, responsible nurses check the management of patients' skin every day to strengthen the attention of medical staff and patients' family members to radiation dermatitis. The degree of skin injury, pain and psychological status were compared between the two groups at the end of radiotherapy.

RESULTS

A total of 120 patients were enrolled in this study. Grade 1 RD was the most common in the observation group at the end of radiotherapy, and Grade 2 and 3 skin RD were less in the observation group than in the control group. There was not significant difference in the scores of SAS and SDS between the two groups before and after nursing (P > 0.05). In the observation group, the SAS scores (44.10±11.25 vs. 32.29 ± 7.72, P = 0.016) and SDS scores (40.98 ± 9.12 vs. 30.11 ± 5.23, P = 0.013) were significantly higher than the control group after nursing(P<0.05). The scores of SAS and SDS in the Observation Group were significantly lower than those in the control group. The scores of SAS in the Observation Group VS the control group were 32.29 ± 7.72 VS 39.09 ± 9.37 after nursing, SDS scores of Observation Group VS control group (30.11 ± 5.23 VS 38.76 ± 7.52, P<0.05). The visual analogue scale (Vas) score in the observation group was significantly lower than that in the control group (2.37 ± 0.45 VS 4.02 ± 0.53, P & Lt; 0.001), and the satisfaction degree of patients in the observation group was significantly higher than that in the control group (96.67% VS 80%, p = 0.004).

CONCLUSION

HFMEA model could effectively reduce incidence of RD, eliminate negative emotion, relieve pain and improve nursing satisfaction.

Spatially resolved transcriptomics: a comprehensive review of their technological advances, applications, and challenges

The ability to explore life kingdoms is largely driven by innovations and breakthroughs in technology, from the invention of the microscope 350 years ago to the recent emergence of single-cell sequencing, by which the scientific community has been able to visualize life at an unprecedented resolution. Most recently, the Spatially Resolved Transcriptomics (SRT) technologies have filled the gap in probing the spatial or even three-dimensional organization of the molecular foundation behind the molecular mysteries of life, including the origin of different cellular populations developed from totipotent cells and human diseases. In this review, we introduce recent progresses and challenges on SRT from the perspectives of technologies and bioinformatic tools, as well as the representative SRT applications. With the currently fast-moving progress of the SRT technologies and promising results from early adopted research projects, we can foresee the bright future of such new tools in understanding life at the most profound analytical level.

Single-cell spatial transcriptome reveals cell-type organization in the macaque cortex

Elucidating the cellular organization of the cerebral cortex is critical for understanding brain structure and function. Using large-scale single-nucleus RNA sequencing and spatial transcriptomic analysis of 143 macaque cortical regions, we obtained a comprehensive atlas of 264 transcriptome-defined cortical cell types and mapped their spatial distribution across the entire cortex. We characterized the cortical layer and region preferences of glutamatergic, GABAergic, and non-neuronal cell types, as well as regional differences in cell-type composition and neighborhood complexity. Notably, we discovered a relationship between the regional distribution of various cell types and the region's hierarchical level in the visual and somatosensory systems. Cross-species comparison of transcriptomic data from human, macaque, and mouse cortices further revealed primate-specific cell types that are enriched in layer 4, with their marker genes expressed in a region-dependent manner. Our data provide a cellular and molecular basis for understanding the evolution, development, aging, and pathogenesis of the primate brain.

An invasive zone in human liver cancer identified by Stereo-seq promotes hepatocyte-tumor cell crosstalk, local immunosuppression and tumor progression

Dissecting and understanding the cancer ecosystem, especially that around the tumor margins, which have strong implications for tumor cell infiltration and invasion, are essential for exploring the mechanisms of tumor metastasis and developing effective new treatments. Using a novel tumor border scanning and digitization model enabled by nanoscale resolution-SpaTial Enhanced REsolution Omics-sequencing (Stereo-seq), we identified a 500 µm-wide zone centered around the tumor border in patients with liver cancer, referred to as "the invasive zone". We detected strong immunosuppression, metabolic reprogramming, and severely damaged hepatocytes in this zone. We also identified a subpopulation of damaged hepatocytes with increased expression of serum amyloid A1 and A2 (referred to collectively as SAAs) located close to the border on the paratumor side. Overexpression of CXCL6 in adjacent malignant cells could induce activation of the JAK-STAT3 pathway in nearby hepatocytes, which subsequently caused SAAs' overexpression in these hepatocytes. Furthermore, overexpression and secretion of SAAs by hepatocytes in the invasive zone could lead to the recruitment of macrophages and M2 polarization, further promoting local immunosuppression, potentially resulting in tumor progression. Clinical association analysis in additional five independent cohorts of patients with primary and secondary liver cancer (n = 423) showed that patients with overexpression of SAAs in the invasive zone had a worse prognosis. Further in vivo experiments using mouse liver tumor models in situ confirmed that the knockdown of genes encoding SAAs in hepatocytes decreased macrophage accumulation around the tumor border and delayed tumor growth. The identification and characterization of a novel invasive zone in human cancer patients not only add an important layer of understanding regarding the mechanisms of tumor invasion and metastasis, but may also pave the way for developing novel therapeutic strategies for advanced liver cancer and other solid tumors.

Single-cell chromatin accessibility profiling of cell-state-specific gene regulatory programs during mouse organogenesis

In mammals, early organogenesis begins soon after gastrulation, accompanied by specification of various type of progenitor/precusor cells. In order to reveal dynamic chromatin landscape of precursor cells and decipher the underlying molecular mechanism driving early mouse organogenesis, we performed single-cell ATAC-seq of E8.5-E10.5 mouse embryos. We profiled a total of 101,599 single cells and identified 41 specific cell types at these stages. Besides, by performing integrated analysis of scATAC-seq and public scRNA-seq data, we identified the critical cis-regulatory elements and key transcription factors which drving development of spinal cord and somitogenesis. Furthermore, we intersected accessible peaks with human diseases/traits-related loci and found potential clinical associated single nucleotide variants (SNPs). Overall, our work provides a fundamental source for understanding cell fate determination and revealing the underlying mechanism during postimplantation embryonic development, and expand our knowledge of pathology for human developmental malformations.

Deep learning for predicting the risk of immune checkpoint inhibitor-related pneumonitis in lung cancer

AIM

To develop and validate a nomogram model that combines computed tomography (CT)-based radiological factors extracted from deep-learning and clinical factors for the early predictions of immune checkpoint inhibitor-related pneumonitis (ICI-P).

MATERIALS AND METHODS

Forty ICI-P patients and 101 patients without ICI-P were divided randomly into the training (n=113) and test (n=28) sets. The convolution neural network (CNN) algorithm was used to extract the CT-based radiological features of predictable ICI-P and calculated the CT score of each patient. A nomogram model to predict the risk of ICI-P was developed by logistic regression.

RESULTS

CT score was calculated from five radiological features extracted by the residual neural network-50-V2 with feature pyramid networks. Four predictors of ICI-P in the nomogram model included a clinical feature (pre-existing lung diseases), two serum markers (absolute lymphocyte count and lactate dehydrogenase), and a CT score. The area under curve of the nomogram model in the training (0.910 versus 0.871 versus 0.778) and test (0.900 versus 0.856 versus 0.869) sets was better than the radiological and clinical models. The nomogram model showed good consistency and better clinical practicability.

CONCLUSION

The nomogram model that combined CT-based radiological factors and clinical factors can be used as a new non-invasive tool for the early prediction of ICI-P in lung cancer patients after immunotherapy with low cost and low manual input.

Deciphering the distinct transcriptomic and gene regulatory map in adult macaque basal ganglia cells

BACKGROUND

The basal ganglia are a complex of interconnected subcortical structures located beneath the mammalian cerebral cortex. The degeneration of dopaminergic neurons in the basal ganglia is the primary pathological feature of Parkinson's disease. Due to a lack of integrated analysis of multiomics datasets across multiple basal ganglia brain regions, very little is known about the regulatory mechanisms of this area.

FINDINGS

We utilized high-throughput transcriptomic and epigenomic analysis to profile over 270,000 single-nucleus cells to create a cellular atlas of the basal ganglia, characterizing the cellular composition of 4 regions of basal ganglia in adult macaque brain, including the striatum, substantia nigra (SN), globus pallidum, and amygdala. We found a distinct epigenetic regulation on gene expression of neuronal and nonneuronal cells across regions in basal ganglia. We identified a cluster of SN-specific astrocytes associated with neurodegenerative diseases and further explored the conserved and primate-specific transcriptomics in SN cell types across human, macaque, and mouse. Finally, we integrated our epigenetic landscape of basal ganglia cells with human disease heritability and identified a regulatory module consisting of candidate cis-regulatory elements that are specific to medium spiny neurons and associated with schizophrenia.

CONCLUSIONS

In general, our macaque basal ganglia atlas provides valuable insights into the comprehensive transcriptome and epigenome of the most important and populous cell populations in the macaque basal ganglia. We have identified 49 cell types based on transcriptomic profiles and 47 cell types based on epigenomic profiles, some of which exhibit region specificity, and characterized the molecular relationships underlying these brain regions.

Polyphenic risk score shows robust predictive ability for long-term future suicidality

Suicides are preventable tragedies, if risk factors are tracked and mitigated. We had previously developed a new quantitative suicidality risk assessment instrument (Convergent Functional Information for Suicidality, CFI-S), which is in essence a simple polyphenic risk score, and deployed it in a busy urban hospital Emergency Department, in a naturalistic cohort of consecutive patients. We report a four years follow-up of that population (n = 482). Overall, the single administration of the CFI-S was significantly predictive of suicidality over the ensuing 4 years (occurrence- ROC AUC 80%, severity- Pearson correlation 0.44, imminence-Cox regression Hazard Ratio 1.33). The best predictive single phenes (phenotypic items) were feeling useless (not needed), a past history of suicidality, and social isolation. We next used machine learning approaches to enhance the predictive ability of CFI-S. We divided the population into a discovery cohort (n = 255) and testing cohort (n = 227), and developed a deep neural network algorithm that showed increased accuracy for predicting risk of future suicidality (increasing the ROC AUC from 80 to 90%), as well as a similarity network classifier for visualizing patient’s risk. We propose that the widespread use of CFI-S for screening purposes, with or without machine learning enhancements, can boost suicidality prevention efforts. This study also identified as top risk factors for suicidality addressable social determinants.

[Efficacy of recombinant human growth hormone treatment in children born small for gestational age with syndromic and non-syndromic short stature]

Objective: To analyse the efficacy of recombinant human growth hormone (rhGH) treatment in children born small for gestational age (SGA) with syndormic and non-syndormic short stature. Methods: The clinical data of 59 children born SGA who were diagnosed as short stature and admitted to the Center of Endocrinology, Genetics and Metabolism, Beijing Children's Hospital from July 2012 to June 2021 were collected and analyzed. According to the 2019 consensus on short stature, they were divided into syndromic group and non-syndromic group. Before treatment and 6, 12, 18 and 24 months after treatment, height standard deviation score (Ht-SDS), difference of height standard deviation (∆Ht-SDS) and homeostasis model assessment-insulin resistance index (HOMA-IR) were compared between groups, while Ht-SDS and HOMA-IR were compared before and after treatment. Independent t test or Kruskal-Wallis test were used for comparison between the 2 groups, and paired t test or Mann-Whitney U test were used for the intra-group comparison. Results: Among the 59 cases, 37 were males and 22 females, aged (5.5±2.3) years. There was no significant difference in Ht-SDS after 12 months of treatment between 2 groups (0.9±0.4 vs. 1.2±0.4, t=1.68, P=0.104) or in height SDS after 24 months of treatment (1.4±0.7 vs. 1.9±0.5, t=1.52, P=0.151). After 12 months of treatment, the insulin resistance index of the non-syndromic group was significantly higher than that of the syndromic group (2.29 (1.43, 2.99) vs. 0.90 (0.55, 1.40), Z=-2.95, P=0.003). There were significant differences in Ht-SDS between 6 months and before treatment, 12 months and 6 months in syndromic type (Z=7.65, 2.83 P<0.001, P=0.020), but all were significant differences in non-syndromic type between 6 months and before treatment, 12 months and 6 months, 18 months and 12 months, 24 months and 18 months (Z=11.95, 7.54, 4.26, 3.83, all P<0.001). Conclusion: The efficacy of rhGH treatment in children born SGA is comparable between syndromic and non-syndromic short stature cases, but non-syndromic children treated with rhGH need more frequent follow-up due to the risk of insulin resistance.

Correlation analysis between risk factors, BMD and serum osteocalcin, CatheK, PINP, β-crosslaps, TRAP, lipid metabolism and BMI in 128 patients with postmenopausal osteoporotic fractures

OBJECTIVE

Our aim is to investigate the correlation between risk factors of postmenopausal osteoporotic fracture, BMD and Bone turnover markers, lipid metabolism and BMI.

SUBJECTS AND METHODS

The Cox proportional hazard model was used to conduct univariate and multivariate analysis to screen the risk factors related to postmenopausal osteoporotic fractures. Blood samples were collected to detect biochemical markers of bone turnover, blood lipids content, and then measure the BMI of the survey subjects. BMD was measured and its correlation with biochemical markers of bone turnover, lipid metabolism and BMI was analyzed.

RESULTS

Cox univariate analysis indicated that average age, menopause, years since menopause, number of deliveries, and limb spasm are associated covariates of postmenopausal osteoporotic fractures. Where, BMD severity, history of hysterectomy or ovariectomy, and years since menopause are significant covariates for the incidence of postmenopausal osteoporotic fractures. The correlation study with lipid metabolism found that the smaller the BMI value, the greater the BMD loss; the smaller the TG value, the greater the BMD loss, exhibiting a downward trend. No difference was observed between HDL-C and LDL-C content, and the difference was not statistically significant (p>0.05). Femoral neck BMD was negatively correlated with CatheK, serum osteocalcin, PINP, β-crosslaps and TRAP, and lumbar spine BMD was also negatively correlated with CatheK, serum osteocalcin, PINP, β-crosslaps and TRAP.

CONCLUSIONS

Biochemical markers of bone turnover are highly expressed in postmenopausal women and increase with the decrease of bone density, which can be used as markers for disease prediction. Combined with BMI, triglyceride and other related indicators, and closely related factors such as the patient's age, the number of deliveries, it is possible to predict the incidence of PMOP fractures early.

Single-Nucleus RNA Sequencing and Spatial Transcriptomics Reveal the Immunological Microenvironment of Cervical Squamous Cell Carcinoma

The effective treatment of advanced cervical cancer remains challenging. Herein, single-nucleus RNA sequencing (snRNA-seq) and SpaTial enhanced resolution omics-sequencing (Stereo-seq) are used to investigate the immunological microenvironment of cervical squamous cell carcinoma (CSCC). The expression levels of most immune suppressive genes in the tumor and inflammation areas of CSCC are not significantly higher than those in the non-cancer samples, except for LGALS9 and IDO1. Stronger signals of CD56+ NK cells and immature dendritic cells are found in the hypermetabolic tumor areas, whereas more eosinophils, immature B cells, and Treg cells are found in the hypometabolic tumor areas. Moreover, a cluster of pro-tumorigenic cancer-associated myofibroblasts (myCAFs) are identified. The myCAFs may support the growth and metastasis of tumors by inhibiting lymphocyte infiltration and remodeling of the tumor extracellular matrix. Furthermore, these myCAFs are associated with poorer survival probability in patients with CSCC, predict resistance to immunotherapy, and might be present in a small fraction (< 30%) of patients with advanced cancer. Immunohistochemistry and multiplex immunofluorescence staining are conducted to validate the spatial distribution and potential function of myCAFs. Collectively, these findings enhance the understanding of the immunological microenvironment of CSCC and shed light on the treatment of advanced CSCC.

Single-cell Stereo-seq reveals induced progenitor cells involved in axolotl brain regeneration

The molecular mechanism underlying brain regeneration in vertebrates remains elusive. We performed spatial enhanced resolution omics sequencing (Stereo-seq) to capture spatially resolved single-cell transcriptomes of axolotl telencephalon sections during development and regeneration. Annotated cell types exhibited distinct spatial distribution, molecular features, and functions. We identified an injury-induced ependymoglial cell cluster at the wound site as a progenitor cell population for the potential replenishment of lost neurons, through a cell state transition process resembling neurogenesis during development. Transcriptome comparisons indicated that these induced cells may originate from local resident ependymoglial cells. We further uncovered spatially defined neurons at the lesion site that may regress to an immature neuron-like state. Our work establishes spatial transcriptome profiles of an anamniote tetrapod brain and decodes potential neurogenesis from ependymoglial cells for development and regeneration, thus providing mechanistic insights into vertebrate brain regeneration.

Cortex periplocae modulates the gut microbiota to restrict colitis and colitis-associated colorectal cancer via suppression of pathogenic Th17 cells

Aberrant microbe-immune cell interaction is a predisposing factor in inflammatory bowel disease (IBD) and colitis-associated cancer (CAC). Cortex Periplocae is a famous traditional Chinese medicine with putative anti-rheumatoid arthritis and anti-dyspepsia effects. Here, we show that the Periploca sepium periplosides (PePs), a cardiac glycosides-free pregnane glycosides extract from root bark of Cortex Periplocae, alleviates colon inflammation, improves intestinal epithelial barrier function, and prevents colitis-associated tumorigenesis in mice with colitis and CAC. Mechanistically, PePs treatment modulates abnormal gut microbiota composition in model mice, especially enriches an anti-inflammatory commensal bacterium A. muciniphila BAA-835. We further demonstrate that the altered gut microbiota following PePs treatment plays an important role in modulation of intestinal Type 17 immunity in both colitis and CAC mouse model. Our results indicate that PePs may be used as a potential gut microbiota modulator to treat IBD and CAC.

Spatiotemporal transcriptomic atlas of mouse organogenesis using DNA nanoball-patterned arrays

Spatially resolved transcriptomic technologies are promising tools to study complex biological processes such as mammalian embryogenesis. However, the imbalance between resolution, gene capture, and field of view of current methodologies precludes their systematic application to analyze relatively large and three-dimensional mid- and late-gestation embryos. Here, we combined DNA nanoball (DNB)-patterned arrays and in situ RNA capture to create spatial enhanced resolution omics-sequencing (Stereo-seq). We applied Stereo-seq to generate the mouse organogenesis spatiotemporal transcriptomic atlas (MOSTA), which maps with single-cell resolution and high sensitivity the kinetics and directionality of transcriptional variation during mouse organogenesis. We used this information to gain insight into the molecular basis of spatial cell heterogeneity and cell fate specification in developing tissues such as the dorsal midbrain. Our panoramic atlas will facilitate in-depth investigation of longstanding questions concerning normal and abnormal mammalian development.

High-resolution 3D spatiotemporal transcriptomic maps of developing Drosophila embryos and larvae

Drosophila has long been a successful model organism in multiple biomedical fields. Spatial gene expression patterns are critical for the understanding of complex pathways and interactions, whereas temporal gene expression changes are vital for studying highly dynamic physiological activities. Systematic studies in Drosophila are still impeded by the lack of spatiotemporal transcriptomic information. Here, utilizing spatial enhanced resolution omics-sequencing (Stereo-seq), we dissected the spatiotemporal transcriptomic changes of developing Drosophila with high resolution and sensitivity. We demonstrated that Stereo-seq data can be used for the 3D reconstruction of the spatial transcriptomes of Drosophila embryos and larvae. With these 3D models, we identified functional subregions in embryonic and larval midguts, uncovered spatial cell state dynamics of larval testis, and revealed known and potential regulons of transcription factors within their topographic background. Our data provide the Drosophila research community with useful resources of organism-wide spatiotemporally resolved transcriptomic information across developmental stages.

Cell transcriptomic atlas of the non-human primate Macaca fascicularis

Studying tissue composition and function in non-human primates (NHPs) is crucial to understand the nature of our own species. Here we present a large-scale cell transcriptomic atlas that encompasses over 1 million cells from 45 tissues of the adult NHP Macaca fascicularis. This dataset provides a vast annotated resource to study a species phylogenetically close to humans. To demonstrate the utility of the atlas, we have reconstructed the cell-cell interaction networks that drive Wnt signalling across the body, mapped the distribution of receptors and co-receptors for viruses causing human infectious diseases, and intersected our data with human genetic disease orthologues to establish potential clinical associations. Our M. fascicularis cell atlas constitutes an essential reference for future studies in humans and NHPs.

795 A POSITIVE 4AT DELIRIUM ASSESSMENT TOOL SCORE ON HOSPITAL ADMISSION IS LINKED TO MORTALITY, LENGTH OF STAY AND ‘HOME TIME’: A STUDY OF 82,770 HOSPITAL ADMISSIONS IN EDINBURGH AND SALFORD

Introduction

Delirium is linked with poor outcomes but studies using large-scale routine data are scarce. The 4AT (www.the4AT.com) is a brief (~2 minutes), well-validated tool for detection of delirium and cognitive impairment. We performed a two-centre study (Edinburgh and Salford) of Electronic Health Record (EHR) 4AT scores and outcomes in 82,770 non-elective hospital admissions in patients aged ≥65. We determined relationships between 4AT scores 0 (no impairment), 1–3 (cognitive impairment but no delirium) and ≥ 4 (delirium), in relation to 30-day inpatient mortality, length of stay, and time at home (‘home time’) in the year following index admission.

Methods

We analysed EHR 4AT scores recorded within 24 hours of admission, and outcomes data were also derived from the EHR. The study period was between April 2016 (Edinburgh)/September 2017 (Salford) and April 2020 (both centres).

Results

4AT scores suggestive of delirium (≥4) were present in 25% in Salford, and 18% in Edinburgh. After adjustment for age and sex, 30-day inpatient mortality with 4AT ≥4 was 5.5-fold greater than the 4AT 0 group in Edinburgh (aOR 5.53, 95% confidence interval [CI] 4.99–6.13) and 3.4-fold greater in Salford (aOR 3.39, 95% CI 2.98–3.87). Length of stay was more than double in patients with any abnormal 4AT score compared to a 4AT score of 0. The median ‘home time’ at 1 year was reduced by 112 days (Edinburgh) and 61 days (Salford) in the 4AT ≥4 compared to 4AT 0 days.

Conclusions

This large study using routine clinical data confirms the relationships between delirium and poor outcomes previously reported in smaller research studies. Further, the results demonstrate the feasibility and value of using a brief clinical tool to identify delirium as a strong marker of adverse outcomes, and will be helpful in guiding policy development around patient safety including better treatment of delirium.

[MicroRNA-132 promotes atherosclerosis by inducing mitochondrial oxidative stressmediated ferroptosis]

OBJECTIVE

To explore the expression of microRNA-132 (miR-132) and its potential role in the development of atherosclerosis (AS).

METHODS

Thirty AS samples and 30 samples of normal peripheral vessels were collected from atherosclerotic patients undergoing peripheral angiostomy in our hospital for detecting the expression level of miR-132 using RT-qPCR. The expression of miR-132 in human umbilical vein endothelial cells (HUVEC) was up-regulated by liposome transfection, and intracellular reactive oxygen species (ROS), localization relationship between ROS and mitochondria, functional changes of mitochondrial reactive oxygen superoxide species (mtROS), mitochondrial membrane potential (MMP) and opening of mitochondrial permeability transition pore (mPTP) were analyzed by flow cytometry and laser confocal microscopy. The activity of mitochondrial redox respiratory chain complex (type I, II, III, IV and V) in HUVECs was detected using ELISA, and the expression levels of key iron death proteins were detected with Western blotting.

RESULTS

RT-qPCR results showed that miR-132 was significantly up-regulated in atherosclerotic plaques compared with normal vascular samples (P < 0.001). Compared with control HUVECs, HUVECs overexpressing miR-132 showed a significantly increased level of intracellular ROS (P < 0.001), and most of ROS was colocalized with mitochondria. HUVECs overexpressing miR-132 also showed significantly decreased MMP (P < 0.001) and obviously increased mtROS (P < 0.001) and opening of mPTP (P < 0.001), which led to mitochondrial REDOX respiratory chain stress disorder. The key iron death protein GPX4 was significantly down-regulated and the oxidized protein NOX4 was significantly increased in miR-132-overexpressing HUVECs (P < 0.001).

CONCLUSION

MiR-132 promotes atherosclerosis by inducing mitochondrial oxidative stress-mediated ferroptosis, which may serve as a promising therapeutic target for AS.

Efficacy of surgical navigation in zygomaticomaxillary complex fractures: randomized controlled trial

Accurate reduction is of vital importance in the treatment of zygomaticomaxillary complex (ZMC) fractures. Computer-assisted navigation systems (CANS) have been employed in ZMC fractures to improve the accuracy of surgical reduction. However, randomized controlled trials on this subject are rare and the benefits of CANS remain controversial. The aim of this study was to compare reduction errors between navigation-aided and conventional surgical treatment for ZMC fractures. Thirty-eight patients with unilateral type B ZMC fractures were enrolled. Preoperative computed tomography data were imported into ProPlan software for virtual surgical planning. Open reduction and internal fixation was performed with CANS (experimental group) or without CANS (control group). Postoperative computed tomography scans were obtained to examine the difference between surgical planning and the actual postoperative outcome, namely reduction errors. The median translational reduction errors in the X, Y, and Z axes were 0.80 mm, 0.40 mm, and 0.80 mm, respectively, in the experimental group and 0.53 mm, 0.86 mm, and 0.83 mm, respectively, in the control group (P > 0.05). The median rotational reduction errors in pitch, roll, and yaw were 0.92°, 2.47°, and 1.54°, respectively, in the experimental group and 1.45°, 3.68°, and 0.76°, respectively, in the control group (P > 0.05). In conclusion, compared with conventional reduction surgery, navigation-aided surgery showed no significant improvement in reduction accuracy in the treatment of type B ZMC fractures (Chinese Clinical Trial Registry, registration number ChiCTR1800015559).

[Application of diffusion-weighted magnetic resonance imaging in evaluating the efficacy of radiotherapy and chemotherapy for esophageal cancer]

This study was a prospective single arm trial conducted in Zhejiang Jinhua Guangfu hospital from February 2018 to June 2020. A total of 39 patients (32 males and 7 females) with esophageal cancer, aged from 44 to 82 (69±9) years were enrolled. Diffusion weighted magnetic resonance imaging(MR-DWI) was implemented to evaluate the changes of apparent diffusion coefficient(ADC) value before and after chemoradiotherapy. The results showed that the ADC value after chemoradiotherapy was higher than that before treatment[(2.03±0.42)×10⁻³ mm ²/s vs (1.60±0.28)×10⁻³ mm²/s], and there was a positive correlation between the increase of ADC value and the prognosis of patients.

[Effects of intestinal flora on the degree of infiltration of tumor-infiltrating lymphocytes in breast cancer]

Objective: To investigate whether the abundance or diversity of intestinal flora in breast cancer (BC) patients effects on the degree of tumor infiltration lymphocytes in breast cancer tissues. Methods: Between March 2017 and October 2017, a total of 80 biopsy-confirmed female patients with BC were enrolled in the present study at the Breast Center of the Fourth Hospital of Hebei Medical University (Shijiazhuang, China), age distribution ranged from 37 to 74 years, which were divided into three groups based on the infiltration of tumor-infiltrating lymphocytes, as follows: high infiltration of TILs (TIL-H) 25 cases, medium infiltration of TILs (TIL-M) 34 cases and low infiltration of TILs (TIL-L) 21 cases. DNA of the intestinal flora was determined by Illumina sequencing and taxonomy of 16S ribosomal RNA genes. Compare the differences in the abundance or diversity of intestinal flora between these three groups. The relationship between tumor-infiltrating lymphocytes and clinical characteristics was analyzed by χ² tested, and the relationship with intestinal flora was analyzed by β diversity. Results: There were 3, 174, 2, 996, and 2, 877 different OUTs in the TIL-H, TIL-M, and TIL-L groups. The β-diversity distribution was statistically significant (weighted UniFrac, P<0.01; unweighted UniFrac, P<0.01) when comparing the three groups (TIL-H vs. TIL-M vs. TIL-L), the differences between TIL-L and TIL-H groups were greatest. Conclusions: The infiltration level of tumor-infiltrating lymphocytes in breast cancer patients was closely related to the diversity of intestinal flora.

P–248 Statistical estimation for incidence of blastocyst trophectoderm vesicles (TVs) and efficacy of assisted hatching (AH)

Study question

The aim of this study is to analyse the association between blastocyst diameter and TVs development, and to examine the efficacy of AH.

Summary answer

Blastocysts with a diameter of more than 170 μm leads to high incidence of TVs and AH applied from the incidence should be effective.

What is known already

TVs are protrusion of trophectoderm cells often observed in expanding blastocyst stages. TVs can be observed in expanding blastocysts regardless of Intracytoplasmic sperm injection (ICSI) and Conventional-IVF (C-IVF), when the internal pressure of blastocysts increase. The rate of TVs incidence in blastocysts inseminated by ICSI is higher than that by C-IVF, due to penetration of the needle into the zona pellucida. Moreover, it has been reported that TVs may inhibit blastocyst hatching. However, the developmental timing of TVs is still unclear, and there is no study that has analysed the association between blastocyst diameter and the incidence of TVs.

Study design, size, duration

1) Diameters and TVs incidence of blastocysts by ICSI and C-IVF were measured, and the cut-off value and the area under the curve (AUC) of the receiver operating characteristic (ROC) curve were calculated to estimate the timing of TV incidence. 2) We analysed the clinical pregnancy rates of blastocysts with TVs treated by AH compared to those of blastocysts by C-IVF not subjected to AH.

Participants/materials, setting, methods

This study included 821 transferred frozen blastocysts ranging from March 2018 to November 2019. The embryos were cultured in a dry incubator after insemination by ICSI or C-IVF. Blastocyst freezing conditions were set at day5 to day7 with a diameter of more than 150 μm in inner diameter of zona pellucida, and this was measured before freezing. The ROC curve was performed using EZR statistical analysis software.

Main results and the role of chance

1) The incidence of TVs in blastocysts by ICSI and C-IVF was 27.5% (117/424) and 14.6% (58/397) respectively. The rate of the incidence of TVs in blastocysts inseminated by ICSI and C-IVF; 8.6% (12/140) and 0.95% (1/105) in 150–159 μm, 12.7% (14/110) and 8.2% (6/73) in 160–169 μm, 40.6% (28/69) and 10.5% (6/57) in 170–179 μm, 55.6% (30/54) and 25.5% (13/51) in 180–189 μm, 66.7% (20/30) and 35.7% (10/28) in 190–199 μm, and 68.4% (13/19) and 26.8% (22/82) in the diameter of more than 200 μm. The cut-off value of the ROC curve was respectively 170 μm (sensitivity 78.6% and specificity 73.0%) and 176 μm (sensitivity 84.5% and specificity 59.6%) in the diameter; the AUC was 0.8 [95%CI:0.752–0.848] and 0.74 [95%CI:0.687–0.793] respectively. 2) The clinical pregnancy rate of TVs blastocyst vs C-IVF blastocyst was 52.7% (88/167) vs 57.8% (37/64) respectively. There is no significant difference between the two clinical pregnancy rates (P = 0.556).

Limitations, reasons for caution

The findings of this study have to be seen in light of some limitations. Since this study aimed to analyse the incidence of TVs based on blastocyst size, we did not take into account the grade according to the Gardner classification and the number of trophectoderm cells.

Wider implications of the findings: Blastocysts inseminated by ICSI and C-IVF were highly likely to have TVs above 170 μm and 176 μm respectively. The clinical pregnancy rates of the blastocyst with TV treated by AH was similar to those of the C-IVF blastocyst.

Trial registration number

Not applicable

[A clinical and pathological report of delayed encephalopathy after heat stroke]

Objective: To explore the clinical manifestations, dynamic neuroimaging changes and brain histopathologic characteristics of a patient with delayed encephalopathy after heat stroke. Methods: In October 2019, the clinical manifestations, electroencephalogram, cerebrospinal fluid, imaging changes and brain histopathological characteristics of a patient with brain damage caused by heat stroke were retrospectively analyzed. Results: The patient was a 40-year-old male who suddenly appeared dizziness, unconscious, high fever when working in the high temperature environment. The EEG showed diffuse slow wave activity. Early CT was normal, and abnormal signals gradually appeared in the basal ganglia region of the thalamus after a few days. In the late, the MRI found a large area of abnormal signals under the cerebral cortex, and white matter was involved. Pathological examination of brain biopsy showed that cortical neuron loss, loose white matter changes, and significant demyelination changes, while no inflammatory cell infiltration was observed in subarachnoid space, meninges, and dermal white matter. Conclusion: Imaging examination dynamic changes of the delayed encephalopathy is important in the heat stroke, and the main pathological manifestation is demyelination.

A Combined sEMG and Accelerometer System for Monitoring Functional Activity in Stroke

Remote monitoring of physical activity using bodyworn sensors provides an alternative to assessment of functional independence by subjective, paper-based questionnaires. This study investigated the classification accuracy of a combined surface electromyographic (sEMG) and accelerometer (ACC) sensor system for monitoring activities of daily living in patients with stroke. sEMG and ACC data were recorded from 10 hemi paretic patients while they carried out a sequence of 11 activities of daily living (Identification tasks), and 10 activities used to evaluate misclassification errors (non-Identification tasks). The sEMG and ACC sensor data were analyzed using a multilayered neural network and an adaptive neuro-fuzzy inference system to identify the minimal sensor configuration needed to accurately classify the identification tasks, with a minimal number of misclassifications from the non-Identification tasks. The results demonstrated that the highest sensitivity and specificity for the identification tasks was achieved using a subset of 4 ACC sensors and adjacent sEMG sensors located on both upper arms, one forearm, and one thigh, respectively. This configuration resulted in a mean sensitivity of 95.0 %, and a mean specificity of 99.7 % for the identification tasks, and a mean misclassification error of < 10% for the non-Identification tasks. The findings support the feasibility of a hybrid sEMG and ACC wearable sensor system for automatic recognition of motor tasks used to assess functional independence in patients with stroke.

[Adrenocortical oncocytic tumors: a clinicopathological analysis of 44 cases]

Objective: To study the clinicopathological features of adrenocortical oncocytic tumors (ACOT) and to compare the diagnostic values of Lin-Weiss-Bisceglia (LWB) score and Helsinki score. Methods: Forty-four cases of ACOT diagnosed at Beijing Friendship Hospital, China from March 2008 to July 2019 were histologically analyzed to evaluate their malignant potential (benign versus malignant) according to two scoring criteria. Immunohistochemical studies (EnVision method) were also used. Results: There were 23 males and 21 females with an average age of 46 years. Histologically, the tumor cells were arranged in trabecular, chrysanthemum-shaped, glandular and microcapsule structures, while clear cells were rare or absent. Most of the tumor cells were moderately atypical, and intranuclear inclusion bodies were conspicuous. Immunohistochemical staining showed that tumor cells were positive for Melan A, inhibin, Syn and calretinin. The average proliferation index was 3% in benign ACOT, about 5% in ACOT of malignant potential, and>20% in malignant ACOT. According to the LWB score, 61.4% (27/44) of the tumors were on the left side and had multiple lesions. The percentage of benign ACOT was 59.1% (26/44), malignant potential 6.8% (3/44), malignant 34.1% (15/44), respectively. Among the 15 malignant ACOT, the mitotic figures>5/50 HPF were found in 13 cases, necrosis in 11 cases and capsule invasion in 10 cases. According to the Helsinki score, 65.9% (29/44) of the tumors were benign, and 34.1% (15/44) were malignant. There was no significant difference between the two scoring standards (P>0.05). During the follow-up of 9 to 144 months, 31 patients survived without disease and 13 patients relapsed or had metastasis. Conclusions: ACOT more likely be benign than malignant. The left side is more common. Malignant tumors are prone to recurrence and metastasis. The morphological parameters (high mitotic index, necrosis, and capsular invasion) in the LWB scoring standards combined with immunohistochemical parameters (Ki-67) in the Helsinki score are helpful for the diagnosis of malignant ACOT and are important predictors of poor prognosis.

QSPR modelling for intrinsic viscosity in polymer-solvent combinations based on density functional theory

Linear and nonlinear quantitative structure-property relationship (QSPR) models were developed based on a dataset with 65 polymer-solvent combinations. Seven quantum chemical descriptors, dipole moment, hardness, chemical potential, electrophilicity index, total energy, HOMO and LUMO orbital energies, were calculated with density functional theory at the B3LYP/6-31 G(d) level for polymers and solvents. Considering the strong correlation between intrinsic viscosity and weight, size, shape as well as topological structure of polymers and solvents, topological descriptors were also applied in this work. Meanwhile, the most appropriate polymer structure representation was investigated by considering 1-5 monomeric repeating units. The molecular descriptors were first screened by using the genetic algorithms-multiple linear regression (GA-MLR), with coefficient of determinations (r2) of 0.78 and 0.83 for the training set and the prediction set, respectively. The support vector machine model (SVM) model based on the selected descriptors subset showed a r2 value of 0.95 for the training set and 0.93 for the prediction set. All statistical results suggest that the established QSPR models have good predictability. Furthermore, a new test set obtained from the literature was used for further validation. The r2 values were 0.81 for the MLR model and 0.90 for the SVM model.

Chemopreventive effect of galangin against benzo(a)pyrene-induced stomach tumorigenesis through modulating aryl hydrocarbon receptor in Swiss albino mice

The present study was aimed to evaluate the chemopreventive potential of galangin against benzo(a)pyrene (BaP)-induced stomach carcinogenesis in Swiss albino mice. Stomach cancer was induced in experimental mice using BaP oral administration. The mice were treated with galangin (10 mg/kg b.wt.) before and during BaP administration. Oral administration of galangin at a dose of 10 mg/kg b.wt. significantly (p < 0.05) prevented the tumor incidence, tumor volume in the experimental animals. Further, galangin pretreatment prevents BaP-induced lipid peroxidation and restores BaP-mediated loss of cellular antioxidants status. It has also been found that galangin prevents BaP-induced activation of phase I detoxification enzymes. Furthermore, galangin pretreatment prevented the BaP-induced overexpression of cytochrome P450s isoform genes (CYP1A1, CYP1B1), aryl hydrocarbon receptor system (AhR, ARNT), transcriptional activators (CBP/p300, NF-kB), tumor growth factors, proto-oncogenes, invasion markers (TGFB, SRC-1, MYC, iNOS, MMP2, MMP9) and Phase II metabolic isoenzyme genes (GST) in the stomach tissue homogenate when compared to the control groups. The western blot results confirm that galangin (10 mg/kg. b.wt.) treatment significantly prevented the BaP-mediated expression of ArR, ARNT, and CYP1A1 proteins in the mouse stomach tissue. Therefore, the present results confirm that galangin prevents BaP-induced stomach carcinogenesis probably through modulating ArR and ARNT expression in the experimental mice.

Physicochemical and functional properties of goat milk whey protein and casein obtained during different lactation stages

During lactation, goat milk contains colostrum, transitional milk, mature milk, and end milk. The protein present in goat milk during different lactation periods has different characteristics. This study aimed to characterize the protein profile of goat milk samples obtained at different lactation stages and to identify changes in the physicochemical and functional properties of whey protein and casein from goat milk collected at 1, 3, 15, 100, and 200 d after calving. The results demonstrated that the lactation period had a great influence on the physicochemical and functional properties of goat milk whey protein and casein, especially the protein properties of colostrum on the first day after delivery. The denaturation temperature, hydrophobicity, and turbidity of whey protein were significantly higher on the first day postpartum than at other lactation periods. Correspondingly, the colostrum whey protein also had better functional properties, such as emulsification, oil holding capacity, and foaming properties on the first day postpartum than at other lactation periods. For casein, the turbidity, particle size, water holding capacity, and foaming properties on the first day after delivery were significantly higher than those at other lactation periods, whereas the denaturation temperature, oil holding capacity, and emulsification followed the opposite trend. For both whey protein and casein, the 2 indicators of emulsifying properties, namely, emulsifying activity index and the emulsion stability, also followed an opposite trend relative to lactation stage, whereas the changes in foaming capacity with the lactation period were completely consistent with the change of foaming stability. These findings could provide useful information for the use of goat milk whey protein and casein obtained during different lactation stages in the dairy industry.

Value of contrast-enhanced ultrasound in the diagnosis of breast US-BI-RADS 3 and 4 lesions with calcifications

AIM

To evaluate the diagnostic performance of contrast-enhanced ultrasound (CEUS) for Breast Imaging-Reporting and Data System for Ultrasound (US-BI-RADS) 3 and 4 lesions with calcifications.

MATERIALS AND METHODS

A retrospective study of 168 breast lesions with calcifications detected on both mammography and conventional ultrasonography (US) in 152 patients were categorised as US-BI-RADS 3-4 at US between June 2009 and June 2018. CEUS scores were obtained based on a CEUS five-point scoring system. The combination of US-BI-RADS and CEUS scores created the Rerated BI-RADS (referred to as CEUS-BI-RADS). All results were compared with the histological findings. The diagnostic performances of US and CEUS-BI-RADS were compared.

RESULTS

The diagnostic sensitivity, specificity, and accuracy of US were 81.8% (95% confidence interval [CI]: 71.6%, 92%), 85% (95% CI: 78.4%, 91.5%), and 83.9% (95% CI: 78.4%, 89.5%), respectively, while those for CEUS-BI-RADS were 98.2% (95% CI: 94.7%, 100%), 90.3% (95% CI: 84.8%, 95.7%), and 92.9% (95% CI: 89%, 96.8%), respectively. The diagnostic sensitivity and accuracy values of CEUS-BI-RADS greatly improved compared with those of US (p=0.003 and p=0.004, respectively). The areas under the receiver operating characteristic (ROC) curves for US and CEUS-BI-RADS were 0.888 (95% CI: 0.840, 0.936) and 0.963 (95% CI: 0.936, 0.989), respectively. The diagnostic efficacy of CEUS-BI-RADS was significantly higher than that of US alone (p=0.004).

CONCLUSION

CEUS-BI-RADS significantly improves the diagnostic accuracy for breast US-BI-RADS 3 and 4 lesions with calcifications compared with US.

Chromatin accessibility and transcriptome landscapes of Monomorium pharaonis brain

The emergence of social organization (eusociality) is a major event in insect evolution. Although previous studies have investigated the mechanisms underlying caste differentiation and social behavior of eusocial insects including ants and honeybees, the molecular circuits governing sociality in these insects remain obscure. In this study, we profiled the transcriptome and chromatin accessibility of brain tissues in three Monomorium pharaonis ant castes: queens (including mature and un-mated queens), males and workers. We provide a comprehensive dataset including 16 RNA-sequencing and 16 assay for transposase accessible chromatin (ATAC)-sequencing profiles. We also demonstrate strong reproducibility of the datasets and have identified specific genes and open chromatin regions in the genome that may be associated with the social function of these castes. Our data will be a valuable resource for further studies of insect behaviour, particularly the role of brain in the control of eusociality.

Regulating a novel domain wall oscillator with a steady frequency by changing the current density

The dynamic behaviors of a domain wall (DW) pinned by a notch pair or a single notch with different notch depths are studied. It is found that, in a relatively large current density range, the oscillation frequency of the DW becomes frozen and independent of current density when pinned by a notch pair with a notch depth larger than 12 nm. The current density range for freezing the frequency can be tuned by the notch depth. A chain of notch pairs is designed to introduce more pinned DWs into the nanowire. By increasing the number of DWs and applying a proper magnetic field, the oscillation amplitude can be greatly enhanced. Our finding suggests that nanowires with a series of deep notch pairs may have an important application in the development of DW based spin-transfer nano-oscillators with a high tolerance for current fluctuation.

Change in the structural and functional properties of goat milk protein due to pH and heat

This study was carried out to investigate the effects of pH and heat on the structure and function of milk proteins by comparing goat milk treated under different pH and temperature conditions. The results showed that pH had a significant effect on the thermal stability of goat milk proteins, and the proteins were least thermally stable at pH 7.7. Except for the pH 6.9 goat milk, the surface hydrophobicities of the milk proteins at various pH values reached their maxima at 85°C. The particle size, zeta potential, and content of regular secondary structure also decreased significantly at 85°C, and the turbidity of milk proteins under alkaline pH conditions was lower than that under acidic conditions. It was concluded that alkaline conditions resulted in better emulsion stability and oil-holding capacity, and acidic conditions offered better foaming ability, foam stability, and water-holding capacity for goat milk protein during heat processing. It can also be seen that 85°C was the key temperature for milk proteins after changing the pH of the milk. This paper provides a theoretical basis for optimizing the processing conditions for goat milk and the applications of goat milk proteins.