GV-971 attenuates α-Synuclein aggregation and related pathology

RATIONALE

Synucleinopathies, including Parkinson's disease (PD), multiple system atrophy (MSA), and dementia with Lewy bodies (DLB), share a distinct pathological feature, that is, a widespread accumulation of α-synuclein (α-syn) in the brain. There is a significant clinical unmet need for disease-modifying treatments for synucleinopathies. Recently, a seaweed-derived mixture of oligosaccharides sodium oligomannate, GV-971, was approved for Phase 2 clinical trials for PD. This study aimed to further evaluate the therapeutic effects of GV-971 on synucleinopathies using cellular and animal models and explore its associated molecular mechanisms.

METHODS

α-Syn aggregation was assessed, in vitro and ex vivo, by ThT assay. A dopaminergic neuron cell line, Prnp-SNCAA53T mice, and brain slices from PD and DLB patients were used to determine the efficacy of GV-971 in ameliorating α-syn pathology. Measurements of motor functions, including pole, cylinder, and rotarod tests, were conducted on Prnp-SNCAA53T mice 4 weeks after intragastric administration of GV-971 (200 mg day-1  kg-1 ).

RESULTS

GV-971 effectively prevented α-syn aggregation and even disassembled pre-aggregated α-syn fibrils, in vitro and ex vivo. In addition, GV-971 was able to rescue α-syn-induced neuronal damage and reduced release of extracellular vesicles (EVs), likely via modulating Alix expression. In the Prnp-SNCAA53T mouse model, when treated at the age of 5 months, GV-971 significantly decreased α-syn deposition in the cortex, midbrain, and cerebellum regions, along with ameliorating the motor dysfunctions.

CONCLUSIONS

Our results indicate that GV-971, when administered at a relatively early stage of the disease process, significantly reduced α-syn accumulation and aggregation in Prnp-SNCAA53T mice. Furthermore, GV-971 corrected α-syn-induced inhibition of EVs release in neurons, contributing to neuronal protection. Future studies are needed to further assess GV-971 as a promising disease-modifying therapy for PD and other synucleinopathies.

Erythrocytic α-Synuclein and the Gut Microbiome: Kindling of the Gut-Brain Axis in Parkinson's Disease

BACKGROUND

Progressive spreading of α-synuclein via gut-brain axis has been hypothesized in the pathogenesis of Parkinson's disease (PD). However, the source of seeding-capable α-synuclein in the gastrointestinal tract (GIT) has not been fully investigated. Additionally, the mechanism by which the GIT microbiome contributes to PD pathogenesis remains to be characterized.

OBJECTIVES

We aimed to investigate whether blood-derived α-synuclein might contribute to PD pathology via a gut-driven pathway and involve GIT microbiota.

METHODS

The GIT expression of α-synuclein and the transmission of extracellular vesicles (EVs) derived from erythrocytes/red blood cells (RBCs), with their cargo α-synuclein, to the GIT were explored with various methods, including radioactive labeling of RBC-EVs and direct analysis of the transfer of α-synuclein protein. The potential role of microbiota on the EVs transmission was further investigated by administering butyrate, the short-chain fatty acids produced by gut microbiota and studying mice with different α-synuclein genotypes.

RESULTS

This study demonstrated that RBC-EVs can effectively transport α-synuclein to the GIT in a region-dependent manner, along with variations closely associated with regional differences in the expression of gut-vascular barrier markers. The investigation further revealed that the infiltration of α-synuclein into the GIT was influenced significantly by butyrate and α-synuclein genotypes, which may also affect the GIT microbiome directly.

CONCLUSION

By demonstrating the transportation of α-synuclein through RBC-EVs to the GIT, and its potential association with gut-vascular barrier markers and gut microbiome, this work highlights a potential mechanism by which RBC α-synuclein may impact PD initiation and/or progression. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

An Immune-Related Gene Prognostic Prediction Risk Model for Neoadjuvant Chemoradiotherapy in Rectal Cancer Using Artificial Intelligence

PURPOSE/OBJECTIVE(S)

To develop and validate an immune-related gene prognostic model (IRGPM) that can predict disease-free survival (DFS) in patients with locally advanced rectal cancer (LARC) who received neoadjuvant chemoradiotherapy and to clarify the immune characteristics of patients with different prognostic risks.

MATERIALS/METHODS

In this study, we obtained transcriptomic and clinical data from the Gene Expression Omnibus (GEO) database and rectal cancer database of West China Hospital. Genes in the RNA immune-oncology panel were extracted. Elastic net was used to identify the immune-related genes that significantly affected the DFS of patients. A prognostic risk model (IRGPM) for rectal cancer was constructed with the random forest method. The prognostic risk score was calculated by the model, and the patients were divided into high- and low-risk groups according to the median risk score. Immune characteristics were analyzed and compared between the high- and low-risk groups.

RESULTS

A total of 407 LARC samples were used in this study. A 20-gene signature was identified by elastic net and was found to be significantly correlated with DFS. The IRGPM was constructed on the basis of the 20 immune-related genes. Kaplan‒Meier survival analysis showed poorer 5-year DFS in the high-risk group than in the low-risk group, and the receiver operating characteristic (ROC) curve suggested good model prediction (areas under the curve (AUCs) of 0.87, 0.94, 0.95 at 1, 3, and 5 years, respectively). The model was validated in the GSE190826 cohort (AUCs of 0.79, 0.64, and 0.63 at 1, 3, and 5 years, respectively) and the cohort from our institution (AUCs of 0.64, 0.66, and 0. 64 at 1, 3, and 5 years, respectively). The differentially expressed genes between the high- and low-risk groups were enriched in cytokine‒cytokine receptor interactions. The patients in the low-risk group had higher immune scores than the patients in the high-risk group. Subsequently, we found that activated B cells, activated CD8 T cells, central memory CD8 T cells, macrophages, T follicular helper cells and type 2 helper cells were more abundant in the low-risk group. Moreover, we compared the expression of immune checkpoints and found that the low-risk group had a higher PDCD1 expression level.

CONCLUSION

The IRGPM, which was constructed based on the random forest and elastic net methods, is a promising method to distinguish DFS in LARC patients treated with a standard strategy. The low-risk group identified by IRGPM was characterized by the activation of adaptive immunity in tumor microenvironment.

[Associations between various lipid components and premature myocardial infarction: a cross-sectional study]

Objective: Hyperlipidemia is closely related to premature acute myocardial infarction (AMI). The present study was performed to explore the correlation between various blood lipid components and the risk of premature AMI. Methods: This is a cross-sectional retrospective study. Consecutive patients with acute ST-segment elevation myocardial infarction (STEMI), who completed coronary angiography from October 1, 2020 to September 30, 2022 in our hospital, were enrolled and divided into premature AMI group (male<55 years old, female<65 years old) and late-onset AMI group. Total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), non-HDL-C, lipoprotein (a) (Lp (a)), apolipoprotein B (ApoB), apolipoprotein A-1 (ApoA-1), non-HDL-C/HDL-C and ApoB/ApoA-1 were analyzed. The correlation between the above blood lipid indexes and premature AMI was analyzed and compared by logistic regression, restricted cubic spline and receiver operating characteristic curve (ROC). Results: A total of 1 626 patients with STEMI were enrolled in this study, including 409 patients with premature AMI and 1 217 patients with late-onset AMI. Logistic regression analysis showed that the risk of premature AMI increased significantly with the increase of TG, non-HDL-C/HDL-C, non-HDL-C, ApoB/ApoA-1, TC and ApoB quintiles; while LDL-C, ApoA-1 and Lp (a) had no significant correlation with premature AMI. The restricted cubic spline graph showed that except Lp (a), LDL-C, ApoA-1 and ApoB/ApoA-1, other blood lipid indicators were significantly correlated with premature AMI. The ROC curve showed that TG and non-HDL-C/HDL-C had better predictive value for premature AMI. Inconsistency analysis found that the incidence and risk of premature AMI were the highest in patients with high TG and high non-HDL-C/HDL-C. Conclusion: TG, non-HDL-C/HDL-C and other blood lipid indexes are significantly increased in patients with premature AMI, among which TG is the parameter, most closely related to premature AMI, and future studies are needed to explore the impact of controlling TG on incidence of premature AMI.

Dual-channel compressed ultrafast photography for Z-pinch dynamic imaging

The compressed ultrafast photography (CUP) can capture non-repetitive time-evolving events at 7 × 10¹³ fps, which is anticipated to find a diverse range of applications in physics, biomedical imaging, and materials science. The feasibility of diagnosing ultrafast phenomenon of Z-pinch by using the CUP has been analyzed in this article. Specifically, a dual-channel CUP design has been adopted for acquiring high quality reconstructed images and the strategies of identical masks, uncorrelated masks, and complementary masks have been compared. Furthermore, the image of the first channel was rotated by 90° to balance the spatial resolution between the sweep direction and the non-sweep direction. Both five synthetic videos and two simulated Z-pinch videos were chosen as the ground truth to validate this approach. The average peak signal to noise ratio of the reconstruction results is 50.55 dB for the self-emission visible light video and 32.53 dB for the laser shadowgraph video with unrelated masks (rotated channel 1). The simulation results show that the time-space-evolving process of plasma distribution can be well retold, and the phenomenon of plasma instability can be accurately diagnosed by the dual-channel CUP with unrelated masks (rotated channel 1). This study may promote the practical applications of the CUP in the field of accelerator physics.

Association between Frailty Assessed Using Two Electronic Medical Record-Based Frailty Assessment Tools and Long-Term Adverse Prognosis in Older Critically Ill Survivors

OBJECTIVES

Frailty has become an independent risk factor for adverse outcomes in critically ill patients. This study aimed to explore the predictive ability of two electronic medical record-based frailty assessment tools, the Hospital Frailty Risk Score (HFRS) and Frailty Index based on physiological and laboratory tests (FI-lab), for long-term adverse prognosis in older critically ill survivors.

DESIGN

Retrospective observational study.

SETTING AND PARTICIPANTS

9,082 critically ill survivors aged ≥ 65 years.

MEASUREMENTS

The HFRS and the 33-item FI-lab were constructed based on the published literature. Cox and logistic regression models assessed the association between frailty and 1-year mortality and post-discharge care needs.

RESULTS

2,586 patients died within 1 year of follow-up. In fully adjusted models, frailty assessed using both the HFRS (per point, hazard ratio [HR] 1.06, 95% confidential interval [CI] 1.05-1.06; intermediate frailty risk, HR 2.00, 95% CI 1.78-2.25; high frailty risk, HR 3.06, 95% CI 2.68-3.50) and FI-lab (per 0.01 points, HR 1.03, 95% CI 1.03-1.03; intermediate frailty risk, HR 1.59, 95% CI 1.44-1.76; high frailty risk, HR 2.30, 95% CI 2.06-2.57) was associated with mortality. Addition of frailty indicators improved the predictive validity of the Sequential Organ Failure Assessment score for mortality (HFRS alone ∆ C-index 0.034; FI-lab alone ∆ C-index 0.016; HFRS and FI-lab combined ∆ C-index 0.042). The HFRS but not the FI-lab was associated with higher probability of post-discharge care needs.

CONCLUSION

Both the HFRS and FI-lab could independently predict 1-year mortality in older critically ill survivors. Adding the HFRS to the SOFA score model improved it more than adding the FI-lab. The greatest improvement was achieved when both frailty indicators were used together. These findings suggest that electronic medical record-based frailty assessment methods can be useful tools for predicting long-term outcomes in older critically ill patients.

A high-speed radiation imaging system based on liquid scintillator filled capillary arrays

A high-speed radiation imaging system based on an image converter of liquid scintillator filled capillary arrays has been developed, which is sensitive to x rays, gamma rays, and neutrons. This imaging system has advantages of both high spatial resolution and high sensitivity because increasing the thickness of the image converter only leads to little deterioration on imaging resolution. The capillary arrays have dimensions of 150 mm diameter and 50 mm thickness, with 100 µm diameter of each capillary. The fluorescence decay time of the filled liquid scintillator based on the mixture of p-xylene and 2,5-diphenyloxazole has been evaluated to be ∼3 ns with the single photon method under the gamma ray excitation. The spatial resolution has been experimentally evaluated to be about 1.15 and 0.6 mm, under excitation of x rays and neutrons, respectively. The imaging system has been applied for diagnosing the dynamic x-ray spot generated by the rod pinch. Two frames in single shot with 15 ns temporal resolution and 20 ns inter-frame separation time have been obtained, which show the spatiotemporal distribution of the electrons bombarding the tungsten rod, indicating the ability of this imaging system in diagnosing dynamic radiation objects. In addition, the technique of capillary arrays provides a promising path for applications of advanced liquid scintillators in the field of radiation imaging.

Study of the intentional replantation procedure used to treat a tooth with a palatogingival groove: A case report

In order to clarify the prognosis of intentional replantation used for palatogingival groove treatment for long-term follow-up observation, the case of a patient with a maxillary lateral incisor with palatogingival groove was investigated. The intentional replantation was carried out to preserve the tooth. The periodontal pocket and the apical bone defect were almost completely repaired at 12-month follow-up. However, the infection was reoccurred after 25-month follow-up examinations. The infected tooth was extracted, of which the root was investigated by histological analysis. Therefore, the reason of the replant failure and the pathways of bacterial infection was investigated.

Key words:Palatogingival groove, intentional tooth replantation, bacterial infection, maxillary lateral incisor.

Development of a Sensitive Diagnostic Assay for Parkinson Disease Quantifying α-Synuclein-Containing Extracellular Vesicles

OBJECTIVE

To develop a reliable and fast assay to quantify the α-synuclein (α-syn)-containing extracellular vesicles (EVs) in CSF and to assess their diagnostic potential for Parkinson disease (PD).

METHODS

A cross-sectional, multicenter study was designed, including 170 patients with PD and 131 healthy controls (HCs) with a similar distribution of age and sex recruited from existing center studies at the University of Washington and Oregon Health and Science University. CSF EVs carrying α-syn or aggregated α-syn were quantified using antibodies against total or aggregated α-syn, respectively, and highly specific, sensitive, and rapid assays based on the novel Apogee nanoscale flow cytometry technology.

RESULTS

No significant differences in the number and size distribution of total EVs between patients with PD and HCs in CSF were observed. When examining the total α-syn-positive and aggregated α-syn-positive EV subpopulations, the proportions of both among all detected CSF EVs were significantly lower in patients with PD compared to HCs (p < 0.0001). While each EV subpopulation showed better diagnostic sensitivity and specificity than total CSF α-syn measured directly with an immunoassay, a combination of the 2 EV subpopulations demonstrated a diagnostic accuracy that attained clinical relevance (area under curve 0.819, sensitivity 80%, specificity 71%).

CONCLUSION

Using newly established, sensitive nanoscale flow cytometry assays, we have demonstrated that total α-syn-positive and aggregated α-syn-positive EVs in CSF may serve as a helpful tool in PD diagnosis.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that total and aggregated α-syn-positive EVs in CSF identify patients with PD.

Liposome-paclitaxel and carboplatin combination chemoradiotherapy for patients with locally advanced esophageal squamous cell carcinoma

PURPOSE

The aim of this study was to evaluate the efficacy of liposome-paclitaxel and carboplatin combination chemoradiotherapy for patients with locally advanced esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

Seventy-nine consecutive patients treated with liposome-paclitaxel based concurrent chemoradiotherapy between January 2015 and December 2019 at Cancer hospital of the University of Chinese Academy of Sciences (Zhejiang cancer hospital) were enrolled in this study. The overall response, toxicities, progression-free survival and overall survival were analyzed with SPSS software.

RESULTS

A total of 302 cycles of weekly chemotherapy were delivered, with a median 4 courses. After concurrent chemoradiotherapy (CCRT), the efficacy was classified as CR in 4 cases (5.1%), PR in 22 cases (28.2%) and SD in 51 cases (65.4%). The median PFS and OS time were 18.2 months and 23.4 months. The 3-year PFS and OS rates were 45.1% and 43.6%, respectively.

CONCLUSIONS

Liposome-paclitaxel and carboplatin concurrent with radiotherapy is a safe and effective modality for locally advanced ESCC. Further clinical investigation are warranted to evaluate the efficacy of this regimen.

Immunoregulation of microglial polarization: an unrecognized physiological function of α-synuclein

Background

Microglial function is vital for maintaining the health of the brain, and their activation is an essential component of neurodegeneration. There is significant research on factors that provoke “reactive” or “inflammatory” phenotypes in conditions of injury or disease. One such factor, exposure to the aggregated or oligomeric forms of α-synuclein, an abundant brain protein, plays an essential role in driving microglial activation; including chemotactic migration and production of inflammatory mediators in Lewy body (LB) diseases such as Parkinson’s disease. On the other hand, it is increasingly recognized that microglia also undergo changes, dependent on the cellular environment, that promote mainly reconstructive and anti-inflammatory functions, i.e., mostly desirable functions of microglia in a physiological state. What maintains microglia in this physiological state is essentially unknown.

Methods

In this study, using in vitro and in vivo models, we challenged primary microglia or BV2 microglia with LPS + IFN-γ, IL-4 + IL-13, α-synuclein monomer, and α-synuclein oligomer, and examined microglia phenotype and the underlying mechanism by RT-PCR, Western blot, ELISA, IF, IHC, Co-IP.

Results

We described a novel physiological function of α-synuclein, in which it modulates microglia toward an anti-inflammatory phenotype by interaction with extracellular signal-regulated kinase (ERK) and recruitment of the ERK, nuclear factor kappa B (NF-κB), and peroxisome proliferator-activated receptor γ (PPARγ) pathways.

Conclusions

These findings suggest a previously unrecognized function of monomeric α-synuclein that likely gives new insights into the pathogenesis and potential therapies for Lewy body-related diseases and beyond, given the abundance and multiple functions of α-synuclein in brain tissue.

Erythrocytic α-synuclein contained in microvesicles regulates astrocytic glutamate homeostasis: a new perspective on Parkinson's disease pathogenesis

Parkinson's disease is a neurodegenerative disorder characterized by the transmission and accumulation of toxic species of α-synuclein (α-syn). Extracellular vesicles (EVs) are believed to play a vital role in the spread of toxic α-syn species. Recently, peripheral α-syn pathology has been investigated, but little attention has been devoted to erythrocytes, which contain abundant α-syn. In this study, we first demonstrated that erythrocyte-derived EVs isolated from Parkinson's disease patients carried elevated levels of oligomeric α-syn, compared to those from healthy controls. Moreover, human erythrocyte-derived EVs, when injected into peripheral blood in a mouse model of Parkinson's disease, were found to readily cross the blood-brain barrier (BBB). These EVs accumulated in astrocyte endfeet, a component of the BBB, where they impaired glutamate uptake, likely via interaction between excitatory amino acid transporter 2 (EAAT2) and oligomeric α-syn. These data suggest that erythrocyte-derived EVs and the oligomeric α-syn carried in them may play critical roles in the progression or even initiation of Parkinson's disease. Additionally, the mechanisms involved are attributable at least in part to dysfunction of astrocytes induced by these EVs. These observations provide new insight into the understanding of the mechanisms involved in Parkinson's disease.

Neural Cell Adhesion Molecule 2 (NCAM2)-Induced c-Src-Dependent Propagation of Submembrane Ca2+ Spikes Along Dendrites Inhibits Synapse Maturation

The neural cell adhesion molecule 2 (NCAM2) is encoded by a gene on chromosome 21 in humans. NCAM2 accumulates in synapses, but its role in regulation of synapse formation remains poorly understood. We demonstrate that an increase in NCAM2 levels results in increased instability of dendritic protrusions and reduced conversion of protrusions to dendritic spines in mouse cortical neurons. NCAM2 overexpression induces an increase in the frequency of submembrane Ca2+ spikes localized in individual dendritic protrusions and promotes propagation of submembrane Ca2+ spikes over segments of dendrites or the whole dendritic tree. NCAM2-dependent submembrane Ca2+ spikes are L-type voltage-gated Ca2+ channel-dependent, and their propagation but not initiation depends on the c-Src protein tyrosine kinase. Inhibition of initiation or propagation of NCAM2-dependent submembrane Ca2+ spikes reduces the NCAM2-dependent instability of dendritic protrusions. Synaptic boutons formed on dendrites of neurons with elevated NCAM2 expression are enriched in the protein marker of immature synapses GAP43, and the number of boutons with mature activity-dependent synaptic vesicle recycling is reduced. Our results indicate that synapse maturation is inhibited in NCAM2-overexpressing neurons and suggest that changes in NCAM2 levels and altered submembrane Ca2+ dynamics can cause defects in synapse maturation in Down syndrome and other brain disorders associated with abnormal NCAM2 expression.

Study Frequency Shift Evaluation of Ultrasound in Fresh and Frozen-thawed Tissues of Cryosurgery by AR Model

BACKGROUND

Noninvasive monitoring of cryosurgery is important for performing precise monitoring of the freezing process in situ and evaluating postoperative effects after therapy. One potential approach is to monitor the normal and freeze-thawed tissues through ultrasonic backscattered signal processing.

OBJECTIVE

A noninvasive method for cryosurgery monitoring based on the analysis of microstructural characteristics of in vitro porcine liver tissues at different state including normal and freeze-thawed tissues by estimating the center frequency of scatterers (CFS) using the autoregressive (AR) cepstrum of ultrasonic backscattered signals.

MATERIALS AND METHODS

The method is based on the discrete scattering model described in the tissue characterization literature and the observation that most biological tissues are semi-regular scattering lattices. A total of ten in vitro porcine liver samples were used and freeze by water bath in the experiments.

RESULTS

Experimental results show that the CFS in porcine liver tissues decreases after pre-frozen and then thawed.

CONCLUSION

The CFS obtained using this method may be used as a characteristic parameter for tissue characterization in noninvasive monitoring the transition zone between frozen and unfrozen tissues during the surgical therapy, and evaluating postoperative effects.

Photon-Induced Weyl Half-Metal Phase and Spin Filter Effect from Topological Dirac Semimetals

Recently discovered Dirac semimetals (DSMs) with two Dirac nodes, such as Na_{3}Bi and Cd_{2}As_{3}, are regarded as carrying the Z_{2} topological charge in addition to the chiral charge. We study the Floquet phase transition of Z_{2} topological DSMs subjected to a beam of circularly polarized light. Owing to the resulting interplay of the chiral and Z_{2} charges, the Weyl nodes are not only chirality dependent but also spin dependent, which constrains the behavior in creation and annihilation of the pair of Weyl nodes. Interestingly, we find a novel phase: One spin band is in the Weyl semimetal phase while the other is in the insulator phase, and we dub it the Weyl half-metal (WHM) phase. We further study the spin-dependent transport in a Dirac-Weyl semimetal junction and find a spin filter effect as a fingerprint of the existence of the WHM phase. The proposed spin filter effect, based on the WHM bulk band, is highly tunable in a broad parameter regime and robust against magnetic disorder, which is expected to overcome the shortcomings of the previously proposed spin filter based on the topological edge or surface states. Our results offer a unique opportunity to explore the potential applications of topological DSMs in spintronics.

MicroRNA-378 acts as a prognosis marker and inhibits cell migration, invasion and epithelial-mesenchymal transition in human glioma by targeting IRG1

OBJECTIVE

Glioma is one common intracranial malignancy. Recently, there has been a large volume of published studies describing the functions of microRNAs as potential diagnostic markers for glioma. Data from several sources revealed that miR-378 played crucial roles in multiple tumors. However, much uncertainty still exists about the functions and underlying mechanism of miR-378. The purpose of the present work was to evaluate the potential effect of miR-378 and verify its influence on the function of IRG1 in glioma.

PATIENTS AND METHODS

The miR-378 expression was examined in 52 pairs of glioma tissues using quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). Transwell assays were conducted to detect the capability of glioma cell migration and invasion with different transfections. Luciferase reporter was used to confirm whether miR-378 could regulate immune responsive gene 1 (IRG1). Western blot was used to measure the expressions of EMT-related markers.

RESULTS

miR 378 expressions were notably reduced in glioma cells and tissues in comparison with controls. The declined miR-378 expressions were correlated with the poor OS and worse clinicopathological parameters of glioma patients. Overexpression of miR-378 repressed glioma cell epithelial-mesenchymal transition (EMT) and metastasis as well as the tumor growth rate and tumor size of glioma mice. Additionally, IRG1 was markedly up-regulated in glioma and was confirmed as a direct target for miR 378 in glioma.

CONCLUSIONS

We showed that the suppressive role of miR-378 in glioma, which was regulated by IRG1, suggested that the miR-378/IRG1 axis may be an effective target for glioma treatment.

Biological membranes in EV biogenesis, stability, uptake, and cargo transfer: an ISEV position paper arising from the ISEV membranes and EVs workshop

Paracrine and endocrine roles have increasingly been ascribed to extracellular vesicles (EVs) generated by multicellular organisms. Central to the biogenesis, content, and function of EVs are their delimiting lipid bilayer membranes. To evaluate research progress on membranes and EVs, the International Society for Extracellular Vesicles (ISEV) conducted a workshop in March 2018 in Baltimore, Maryland, USA, bringing together key opinion leaders and hands-on researchers who were selected on the basis of submitted applications. The workshop was accompanied by two scientific surveys and covered four broad topics: EV biogenesis and release; EV uptake and fusion; technologies and strategies used to study EV membranes; and EV transfer and functional assays. In this ISEV position paper, we synthesize the results of the workshop and the related surveys to outline important outstanding questions about EV membranes and describe areas of consensus. The workshop discussions and survey responses reveal that while much progress has been made in the field, there are still several concepts that divide opinion. Good consensus exists in some areas, including particular aspects of EV biogenesis, uptake and downstream signalling. Areas with little to no consensus include EV storage and stability, as well as whether and how EVs fuse with target cells. Further research is needed in these key areas, as a better understanding of membrane biology will contribute substantially towards advancing the field of extracellular vesicles.

[High level of hemoglobin during the first trimester of pregnancy associated with the risk of gestational diabetes mellitus]

Objective: To explore the relationship between hemoglobin (Hb) level during the first trimester of pregnancy and gestational diabetes mellitus (GDM). Methods: A total of 1 276 participants, who underwent scheduled prenatal examination and normal singleton delivery at the Fifth People's Hospital of Shanghai and Hospital of Intergrated Chinese and Western Medicine in Minhang District, from January 2016 to May 2018 were included. There were 99 cases of GDM (GDM group) and 1 177 cases of normal (control group) pregnant women.Based on the serum Hb level during the first trimester of pregnancy, participants were divided into three groups, 236 cases of low Hb level group (Hb<110 g/L), 868 cases of normal Hb level group (110 g/L≤Hb<130 g/L), and 172 cases of high Hb level group (Hb≥130 g/L). Maternal clinical data were collected, including Hb level during the first trimester of pregnancy, three-point blood glucose (BG) of oral glucose tolerance test (OGTT) and fasting insulin during the second trimester of pregnancy. Homeostasis model assessment of insulin resistance index (HOMA-IR) and homeostasis model assessment of pancreatic β cell function index (HOMA-β) were used to evaluate insulin resistance and pancreatic β cell function. Results: (1) Hb level during the first trimester of pregnancy in GDM group was significantly higher than that in control group [(123±10),(119±11) g/L, P<0.05]. There were no significant difference in gravidity, parity, index of liver and renal function (all P>0.05). (2) Pre-pregnancy body mass index (BMI), 1-hour BG and 2-hour BG of OGTT were significantly increased in the high Hb level group during the first trimester of pregnancy, which were (23±4) kg/m(2), (7.3±2.0) mmol/L, and (6.5±1.4) mmol/L (P<0.05), respectively. The pre-pregnancy BMI, 1-hour BG and 2-hour BG of the normal or low Hb level group were (22±3) kg/m(2), (6.7±1.6) mmol/L, (6.1±1.2) mmol/L; (22±3) kg/m(2), (6.5±1.5) mmol/L, (5.9±1.1) mmol/L, respectively. There were no statistically significant difference in levels of fasting blood glucose, fasting insulin, HOMA-IR and HOMA-β within 3 groups (all P>0.05). (3) In the high Hb level group, prevalence of pregnancy overweight or obesity and GDM were the highest, which were 37.2%(64/172) and 15.1%(26/172), respectively; the differences were statistically significant (all P<0.05). (4) The serum Hb level in the first trimester was positively related with pre-pregnancy BMI (r=0.130, P<0.05), 1-hour BG (r=0.129, P<0.05), 2-hour BG (r=0.134, P<0.05), fasting insulin (r=0.096, P<0.05), and HOMA-IR (r=0.101, P<0.05).Logistic regression indicated that Hb≥130 g/L during the first trimester of pregnancy was an independent risk factor for GDM (OR=2.799, 95%CI: 1.186-6.604; P<0.05). Conclusion: The high level of Hb (Hb≥130 g/L) during the first trimester of pregnancy is associated with GDM.

Topological valley pumping in Weyl semimetals

We investigate the topological pumping effect in Weyl semimetals, subject to the modulation of two ac electric fields along y  and z directions, respectively. We show that the pumping effect originates from the anomalous velocity related to the Berry curvature. The direction of the pumping current is dependent on the chirality of the Weyl fermions. While the total particle current is vanishing because the Weyl points of opposite chirality always come in pairs in Weyl semimetals, the pump gives rise to a net chirality current or valley current. The noiseless valley current generated can be useful in valleytronic applications.

Mass spectrometry: A platform for biomarker discovery and validation for Alzheimer's and Parkinson's diseases

Accurate, reliable, and objective biomarkers for Alzheimer's disease (AD), Parkinson's disease (PD), and related age-associated neurodegenerative disorders are urgently needed to assist in both diagnosis, particularly at early stages, and monitoring of disease progression. Technological advancements in protein detection platforms over the last few decades have resulted in a plethora of reported molecular biomarker candidates for both AD and PD; however, very few of these candidates are developed beyond the discovery phase of the biomarker development pipeline, a reflection of the current bottleneck within the field. In this review, the expanded use of selected reaction monitoring (SRM) targeted mass spectrometry will be discussed in detail as a platform for systematic verification of large panels of protein biomarker candidates prior to costly validation testing. We also advocate for the coupling of discovery-based proteomics with modern targeted MS-based approaches (e.g., SRM) within a single study in future workflows to expedite biomarker development and validation for AD and PD. It is our hope that improving the efficiency within the biomarker development process by use of an SRM pipeline may ultimately hasten the development of biomarkers that both decrease misdiagnosis of AD and PD and ultimately lead to detection at early stages of disease and objective assessment of disease progression. This article is part of the special issue "Proteomics".

Quantum Oscillations of the Positive Longitudinal Magnetoconductivity: A Fingerprint for Identifying Weyl Semimetals

Weyl semimetals (WSMs) host charged Weyl fermions as emergent quasiparticles. We develop a unified analytical theory for the anomalous positive longitudinal magnetoconductivity (LMC) in a WSM, which bridges the gap between the classical and ultraquantum approaches. More interestingly, the LMC is found to exhibit periodic-in-1/B quantum oscillations, originating from the oscillations of the nonequilibrium chiral chemical potential. The quantum oscillations, superposed on the positive LMC, are a remarkable fingerprint of a WSM phase with a chiral anomaly, whose observation is a valid criteria for identifying a WSM material. In fact, such quantum oscillations were already observed by several experiments.

New windows into the brain: Central nervous system-derived extracellular vesicles in blood

Extracellular vesicles (EVs), including exosomes and (shedding) microvesicles, are released by nearly all cell types and carry a cargo of proteins and nucleic acids that varies by the cell of origin. They are thought to play critical roles in normal central nervous system (CNS) function and neurological disorders. A recently revealed key characteristic of EVs is that they may travel between the CNS and peripheral circulation. This property has led to intense interest in how EVs might serve as a vehicle for toxic protein clearance and as a readily accessible source of biomarkers for CNS disorders. Furthermore, by bypassing the blood-brain barrier, modified EVs could serve as a unique drug delivery system that targets specific neuronal populations. Further work is necessary to develop and optimize techniques that enable high-yield capture of relevant EV populations, analyze individual EVs and their cargos, and validate preliminary results of EV-derived biomarkers in independent cohorts.

Texture Feature Differences between Fresh and Frozen-thawed Ex-vivo Porcine Liver Tissue in B-mode Ultrasonic Imaging

BACKGROUND

Ultrasound guidance of cryotherapy could be improved if changes of tissue characterization parameters during freezing could be used to monitor freezing profiles and estimate frostbite distributions.

OBJECTIVE

To investigate if B-mode ultrasonic imaging can provide sufficient information to define the damaged zone during cryotherapy by quantifying the differences of texture features between fresh and frozen-thawed porcine liver tissue.

MATERIALS AND METHODS

The B-mode ultrasonic images were obtained from ten porcine liver tissue samples before and after frozen-thawing treatment, then 20 texture parameters of the grey level histogram (GLH) and the grey level co-occurrence matrix (GLCM) from each image were extracted and analyzed statistically.

RESULTS

It was found that the differences in two texture parameters between the fresh and frozen-thawed tissue are significant enough for diagnostic purpose (variance: 317.0%, contrast: 144.4%).

CONCLUSION

Texture feature analysis of B-mode ultrasonic images can effectively differentiate the fresh and frozen-thawed porcine liver tissues, which offers a prospect for the future practice of evaluating the effectiveness of cryotherapy using Ultrasound.

Clinical management and prevention of dental caries in athletes: A four-year randomized controlled clinical trial

The aims of this four-year randomized controlled clinical trial were to gain insights into management and prevention of dental caries and the effect of stannous fluoride products in athletes. Fifty-four participants were randomized into test and control groups. The test group used special stannous fluoride products. The primary endpoint dental caries was assessed by the ICDAS-II-System and analyzed both by a linear mixed model for repeated measures and a generalized linear mixed model. During the observation period an increase in caries-free surfaces from 64.91 ± 6.42 at baseline to 73.22 ± 4.43 was observed. In surfaces with caries superficialis and caries media, a decrease from 13.94 ± 5.70 and 2.96 ± 2.55 surfaces at baseline to 7.89 ± 3.18 and 0.46 ± 0.78 after 2.5 years was noted, respectively. The analysis showed no effect of stannous fluoride products, but a significant difference for the time of examination (p < 0.0001). In addition, it could be shown that at any time of examination, the odds of developing caries media on a new surface was significantly lower than at baseline (up to 25-times). Due to biannual dental examinations, professional tooth cleaning and restorative treatment the number of caries-free surfaces increased and the odds of a new surface to be afflicted with caries media decreased 25-fold.

Time-reversal invariant resonant backscattering on a topological insulator surface driven by a time-periodic gate voltage

We study the scattering of the Dirac electrons by a point-like nonmagnetic impurity on the surface of a topological insulator, driven by a time-periodic gate voltage. It is found that, due to the doublet degenerate crossing points of different Floquet sidebands, resonant backscattering can happen for the surface electrons, even without breaking the time-reversal (TR) symmetry of the topological surface states (TSSs). The energy spectrum is reshuffled in a way quite different from that for the circularly polarized light, so that new features are exhibited in the Friedel oscillations of the local charge and spin density of states. Although the electron scattering is dramatically modified by the driving voltage, the 1/ρ scale law of the spin precession persists for the TSSs. The TR invariant backscattering provides a possible way to engineer the Dirac electronic spectrum of the TSSs, without destroying the unique property of spin-momentum interlocking of the TSSs.

Anti-hepatitis G E2 Antibody Detection and Its Relation to Serum HGV-RNA in Patients with Clotting Disorders: High Prevalence of HGV Infection and Spontaneous Remission

In a previous study, we have determined the prevalence of serum HGV-RNA in patients with congenital clotting disorders. Twenty-six (15%) of 175 patients investigated were serum HGV-RNA positive. In addition, HGV-RNA was detectable in peripheral blood mononuclear cells (PBMC) in ten percent of the cases, three of these patients were serum HGV-RNA negative.

In the present study, we have determined the prevalence of anti-HGV-E2 antibodies in the same patient population. Anti-HGV-E2 as determined by ELISA was detected in 45 patients (25.7%). Forty of these patients were serum HGV-RNA negative.

Ninety-two percent of the 26 HGV viremic patients and all but one patient (44 patients) with detectable anti-HGV-E2 had coinfection with the hepatitis C virus (HCV). Of these coinfected patients, 62.5% of HGV viremic patients and 53% of anti-HGV-E2 positive patients showed elevated serum ALT levels. Anti-HGV-E2 seroconversion is thus not associated with HCV infection. Two patients who were solely infected with HGV had normal serum ALT levels. In a retrospective longitudinal study, we have observed in 15 patients that serum HGV-RNA persisted during one to 19 years of follow-up, while anti-HGV-E2 was repeatedly negative. Five additional patients who were anti-HGV-E2 positive with concomitant detectable HGV-RNA (4 patients in serum and 1 patient in PBMC) became HGV-RNA negative during follow-up, ranging from 1 to 8 years after the first detection of anti-HGV-E2 antibodies. Two patients had lost anti-HGV-E2 antibodies 3 to 6 years after the seroconversion without the re-appearance of serum HGV-RNA. From these findings, it is clear that the prevalence rate of HGV infection in patients with clotting disorders as determined by PCR assay for HGV-RNA and anti-HGV-E2 by ELISA is actually higher than the prevalence of HGV viremia. Although HGV viremia may persist for longer than 19 years, most of the patients infected with HGV may clear the viremia spontaneously. The clearance of viremia is usually associated with seroconversion to anti-HGVE2. In addition, anti-HGV-E2 may be lost during years of follow-up without the reappearance of the HGV-RNA. Although HGV infection does not seem to influence the fate of HCV infection and does not induce increased levels of serum ALT, the clinical significance of long-term infection remains to be established.

Transmission of α-synuclein-containing erythrocyte-derived extracellular vesicles across the blood-brain barrier via adsorptive mediated transcytosis: another mechanism for initiation and progression of Parkinson's disease?

Parkinson’s disease (PD) pathophysiology develops in part from the formation, transmission, and aggregation of toxic species of the protein α-synuclein (α-syn). Recent evidence suggests that extracellular vesicles (EVs) may play a vital role in the transport of toxic α-syn between brain regions. Moreover, increasing evidence has highlighted the participation of peripheral molecules, particularly inflammatory species, which may influence or exacerbate the development of PD-related changes to the central nervous system (CNS), although detailed characterization of these species remains to be completed. Despite these findings, little attention has been devoted to erythrocytes, which contain α-syn concentrations ~1000-fold higher than the cerebrospinal fluid, as a source of potentially pathogenic α-syn. Here, we demonstrate that erythrocytes produce α-syn-rich EVs, which can cross the BBB, particularly under inflammatory conditions provoked by peripheral administration of lipopolysaccharide. This transport likely occurs via adsorptive-mediated transcytosis, with EVs that transit the BBB co-localizing with brain microglia. Examination of microglial reactivity upon exposure to α-syn-containing erythrocyte EVs in vitro and in vivo revealed that uptake provoked an increase in microglial inflammatory responses. EVs derived from the erythrocytes of PD patients elicited stronger responses than did those of control subjects, suggesting that inherent characteristics of EVs arising in the periphery might contribute to, or even initiate, CNS α-syn-related pathology. These results provide new insight into the mechanisms by which the brain and periphery communicate throughout the process of synucleinopathy pathogenesis.

Analytical theory and possible detection of the ac quantum spin Hall effect

We develop an analytical theory of the low-frequency ac quantum spin Hall (QSH) effect based upon the scattering matrix formalism. It is shown that the ac QSH effect can be interpreted as a bulk quantum pumping effect. When the electron spin is conserved, the integer-quantized ac spin Hall conductivity can be linked to the winding numbers of the reflection matrices in the electrodes, which also equal to the bulk spin Chern numbers of the QSH material. Furthermore, a possible experimental scheme by using ferromagnetic metals as electrodes is proposed to detect the topological ac spin current by electrical means.

Theory of Inverse Edelstein Effect of The Surface States of A Topological Insulator

The surface states of three-dimensional topological insulators possess the unique property of spin-momentum interlocking. This property gives rise to the interesting inverse Edelstein effect (IEE), in which an applied spin bias μ is converted to a measurable charge voltage difference V. We develop a semiclassical theory for the IEE of the surface states of Bi2Se3 thin films, which is applicable from the ballistic regime to diffusive regime. We find that the efficiency of the spin-charge conversion, defined as γ = V/μ, exhibits a universal dependence on the ratio between sample size and electron mean free path. The efficiency increases from γ = π/4 in the ballistic limit to γ = π in the diffusive limit, suggesting that sufficient strength of impurity scattering is favorable for the IEE.

The further exploration of hidden blood loss in posterior lumbar fusion surgery

PURPOSE

Hidden blood loss (HBL) plays an important role in lumbar fusion surgery. However, there was huge computation error when calculating hidden loss in previous studies because they regarded the volume of drainage as postoperative blood loss. We should not ignore the fact that the composition of drainage varies from person to person and also with time-lapse after operation. The purpose of this study was to demonstrate a more accurate HBL calculation formula by comparing it with previous formula and to address the importance of HBL in patients undergoing posterior lumbar fusion surgeries.

METHODS

For each patient, the HBL was calculated by previous formula and our recommendable formula. We compared the result of HBL calculated by two different methods. At the same time, we explored the HBL in patients undergoing posterior lumbar fusion surgeries with various levels.

RESULTS

In our study, the average total blood loss was 771ml. The mean intraoperative blood loss was 268ml, and the total volume of post-operative drainage is 276ml. The mean hidden loss of 90 patients calculated with previous method was 227ml and 29.4% of total loss. When taking change of drainage HCT into account, the mean hidden loss calculated with our recommendable method was 362.8ml and 47% of total loss. The results were significantly different (P<0.01). There was no significant difference in the percentage of the HBL between patients with single or multiple surgical levels.

CONCLUSIONS

There is often a substantial unmeasured blood loss in lumbar fusion surgeries. However, the component of drainage changed radically with time, we should take the true blood contained in drainage into considerations when calculating the HBL.

LEVEL OF EVIDENCE

Our research is a case-control study and the level of proof is III.

Mutant p53 upregulates alpha-1 antitrypsin expression and promotes invasion in lung cancer

Missense mutations in the TP53 tumor-suppressor gene inactivate its antitumorigenic properties and endow the incipient cells with newly acquired oncogenic properties that drive invasion and metastasis. Although the oncogenic effect of mutant p53 transcriptome has been widely acknowledged, the global influence of mutant p53 on cancer cell proteome remains to be fully elucidated. Here, we show that mutant p53 drives the release of invasive extracellular factors (the 'secretome') that facilitates the invasion of lung cancer cell lines. Proteomic characterization of the secretome from mutant p53-inducible H1299 human non-small cell lung cancer cell line discovered that the mutant p53 drives its oncogenic pathways through modulating the gene expression of numerous targets that are subsequently secreted from the cells. Of these genes, alpha-1 antitrypsin (A1AT) was identified as a critical effector of mutant p53 that drives invasion in vitro and in vivo, together with induction of epithelial-mesenchymal transition markers expression. Mutant p53 upregulated A1AT transcriptionally through the involvement with its family member p63. Conditioned medium containing secreted A1AT enhanced cell invasion, while an A1AT-blocking antibody attenuated the mutant p53-driven migration and invasion. Importantly, high A1AT expression correlated with increased tumor stage, elevated p53 staining and shorter overall survival in lung adenocarcinoma patients. Collectively, these findings suggest that A1AT is an indispensable target of mutant p53 with prognostic and therapeutic potential in mutant p53-expressing tumors.

Experimental Observation of Anisotropic Adler-Bell-Jackiw Anomaly in Type-II Weyl Semimetal WTe_{1.98} Crystals at the Quasiclassical Regime

The asymmetric electron dispersion in type-II Weyl semimetal theoretically hosts anisotropic transport properties. Here, we observe the significant anisotropic Adler-Bell-Jackiw (ABJ) anomaly in the Fermi-level delicately adjusted WTe_{1.98} crystals. Quantitatively, C_{W}, a coefficient representing the intensity of the ABJ anomaly along the a and b axis of WTe_{1.98} are 0.030 and 0.051  T^{-2} at 2 K, respectively. We found that the temperature-sensitive ABJ anomaly is attributed to a topological phase transition from a type-II Weyl semimetal to a trivial semimetal, which is verified by a first-principles calculation using experimentally determined lattice parameters at different temperatures. Theoretical electrical transport study reveals that the observation of an anisotropic ABJ along both the a and b axes in WTe_{1.98} is attributed to electrical transport in the quasiclassical regime. Our work may suggest that electron-doped WTe_{2} is an ideal playground to explore the novel properties in type-II Weyl semimetals.

Investigation of an InP-based image converter with optical excitation

An image converter based on an indium phosphide has been developed to measure the two-dimensional spatial profile of the incident photon flux by probing the rapid change of the refractive index in the semiconductor. The spatial resolution, dynamic range, and temporal response of this image converter have been investigated with optical methods. The results show that the spatial resolution is ∼15 cycles/mm at the percent modulation transfer function of 0.5, the dynamic range is about 100, and the time response is in the order of 600 ps. This scheme can provide an alternative choice as an imaging diagnostic for experiments in the area of high-energy density physics.

The risk predictive values of UK-PBC and GLOBE scoring system in Chinese patients with primary biliary cholangitis: the additional effect of anti-gp210

BACKGROUND

Adequate risk stratification is critical for the management of the patients with primary biliary cholangitis (PBC). The UK-PBC and GLOBE scoring systems for prognosis of PBC have been proposed recently, but have not been validated in Asian population.

AIM

To validate the UK-PBC and GLOBE scoring systems in Chinese patients for prognosis of PBC. To clarify the role of anti-gp210 as a biomarker, and to investigate whether anti-gp210 could affect the prognostic values of UK-PBC and GLOBE scoring systems.

METHODS

We retrospectively analysed 276 patients with PBC evaluated between September 2004 and May 2016, including 133 anti-gp210+ and 143 anti-gp210- patients.

RESULTS

The 5-year adverse outcome-free survivals of anti-gp210+ vs. anti-gp210- patients were 70% and 85%, respectively (P = 0.005). Cirrhosis (P = 0.001), albumin level ≤40 g/L (P = 0.011) and platelet count ≤153 × 10⁹ (P < 0.001) had a superimposition effect on anti-gp210 antibody as a risk factor. Furthermore, long-term prognoses were evaluated using the UK-PBC and GLOBE scores. For UK-PBC scoring system, the area under receiver operating characteristic curve (AUROC) was 0.924 for all patients with PBC (n = 223), 0.940 for anti-gp210+ patients (n = 110) and 0.888 for anti-gp210- patients (n = 113). For GLOBE scoring system, the area under receiver operating characteristic curve was 0.901 for all patients with PBC (n = 223), 0.924 for anti-gp210+ patients (n = 110) and 0.848 for anti-gp210- patients (n = 113). UK-PBC score >0.0578 (P < 0.001, HR: 32.736, 95% CI: 11.368-94.267) and GLOBE score <0.850 (P < 0.001, HR: 18.763, 95% CI: 7.968-44.180) were associated with poorer outcomes in the whole cohort.

CONCLUSIONS

The UK-PBC and GLOBE scoring systems were good 5-year prognostic predictors in Chinese patients with PBC, especially in anti-gp210+ patients. As a biomarker, anti-gp210 antibody was associated with a more severe cholestatic manifestation and a worse long-term prognosis. The anti-gp210 antibody could be added to further optimise the UK-PBC and GLOBE scoring systems.

Time-reversal-breaking induced quantum spin Hall effect

We show that quantum spin Hall (QSH) effect does not occur in a square lattice model due to cancellation of the intrinsic spin-orbit coupling coming from different hopping paths. However, we show that QSH effect can be induced by the presence of staggered magnetic fluxes alternating directions square by square. When the resulting Peierls phase takes a special value , the system has a composite symmetry ΘΡ₋ with Θ the time-reversal operator and Ρ₋ transforming the Peierls phase from γ to γ − , which protects the gapless edge states. Once the phase deviates from , the edge states open a gap, as the composite symmetry is broken. We further investigate the effect of a Zeeman field on the QSH state, and find that the edge states remain gapless for . This indicates that the QSH effect is immune to the magnetic perturbation.

Abstract P4-05-02: Conditional inactivation of the 25-hydroxyvitamin D-24-hydroxylase (Cyp24a1) in the mouse mammary epithelium alters mammary gland development

The biologically active form of vitamin D (1,25(OH)2D) regulates proliferation, differentiation, and apoptosis in diverse cell types. We have previously identified anti-proliferative activities of 1,25(OH)2D in human breast tissue, as well as 1,25(OH)2D target gene expression consistent with reports that elevated vitamin D levels may protect against cancer. In mouse studies, vitamin D signaling modulates normal mammary gland development, including ductal outgrowth and branching, and protects against tumorigenesis. Degradation of 1,25(OH)2D is initiated by the enzyme Cyp24a1 in target tissues, providing critical local control of 1,25(OH)2D bioactivity. In vitro, blockade of Cyp24a1 activity potentiates the anti-proliferative effects of 1,25(OH)2D. However, the extent to which endogenous Cyp24a1 activity within the mammary epithelium regulates local 1,25(OH)2D levels to modulate normal mammary gland development, with possible implications for cancer, has not been investigated. We generated a novel mouse model with conditional knockout of the Cyp24a1 gene specifically in the mammary epithelium (MMTV-Cre x Cyp24a1lox/lox). Ablation of Cyp24a1 activity in the mammary epithelium does not alter either gland or body weight at 4, 6 or 10 weeks of age. Preliminary analyses of mammary gland whole mounts indicate that virgin knockout mice form fewer terminal end buds compared to glands from wild-type littermates at 4 and 6 weeks of age (P&lt;0.05). Moreover, the width of the ducts proximal to the central lymph node of knockout mice was less than that of wild-type mice at 4 and 10 weeks of age (P&lt;0.05 and P&lt;0.01, respectively). In addition, the number of secondary and tertiary branching points is reduced in mammary glands from knockout mice at 6 weeks of age (P&lt;0.05 and P&lt;0.01, respectively). In summary, our findings suggest that Cyp24a1 activity within epithelial cells plays a crucial role to modulate postnatal mammary gland development, presumably by limiting the local accumulation of 1,25(OH)2D.

Topological phases of the kicked Harper-Kitaev model with ultracold atoms

We propose using ultracold atoms trapped in a one-dimensional periodically driven optical lattice to realize the Harper-Kitaev model, where the on-site energies are periodically kicked. Such a system provides a natural platform to study both Chern insulators and Majorana fermions. Based on calculating the quasienergy spectra, we find that both Floquet Majorana modes and Hall chiral edge modes could appear at the sample boundary in the gaps between the quasienergy bands. We also study the competition of topological superconductor and Chern insulator states in the model. We calculate the [Formula: see text] index and Floquet Chern number to characterize the above two different topological states, including the topological phase transitions in the kicked Harper-Kitaev model with the increase in the strength of the kick.

π Spin Berry Phase in a Quantum-Spin-Hall-Insulator-Based Interferometer: Evidence for the Helical Spin Texture of the Edge States

The quantum spin Hall insulator is characterized by helical edge states, with the spin polarization of the electron being locked to its direction of motion. Although the edge-state conduction has been observed, unambiguous evidence of the helical spin texture is still lacking. Here, we investigate the coherent edge-state transport in an interference loop pinched by two point contacts. Because of the helical character, the forward interedge scattering enforces a π spin rotation. Two successive processes can only produce a nontrivial 2π or trivial 0 spin rotation, which can be controlled by the Rashba spin-orbit coupling. The nontrivial spin rotation results in a geometric π Berry phase, which can be detected by a π phase shift of the conductance oscillation relative to the trivial case. Our results provide smoking gun evidence for the helical spin texture of the edge states. Moreover, it also provides the opportunity to all electrically explore the trajectory-dependent spin Berry phase in condensed matter.

Topological spin and valley pumping in silicene

We propose to realize adiabatic topological spin and valley pumping by using silicene, subject to the modulation of an in-plane ac electric field with amplitude Ey and a vertical electric field consisting of an electrostatic component and an ac component with amplitudes and . By tuning and , topological valley pumping or spin-valley pumping can be achieved. The low-noise valley and spin currents generated can be useful in valleytronic and spintronic applications. Our work also demonstrates that bulk topological spin or valley pumping is a general characteristic effect of two-dimensional topological insulators, irrelevant to the edge state physics.

Zeeman-Field-Tuned Topological Phase Transitions in a Two-Dimensional Class-DIII Superconductor

We investigate the topological phase transitions in a two-dimensional time-reversal invariant topological superconductor in the presence of a Zeeman field. Based on the spin Chern number theory, we find that the system exhibits a number of topologically distinct phases with changing the out-of-plane component of the Zeeman field, including a quantum spin Hall-like phase, quantum anomalous Hall-like phases with total Chern number C = −2, −1, 1 and 2, and a topologically trivial superconductor phase. The BdG band gap closes at each boundary of the phase transitions. Furthermore, we demonstrate that the zero bias conductance provides clear transport signatures of the different topological phases, which are robust against symmetry-breaking perturbations.

Characterization of Normal and Freeze-Thawed Tissues in vitro Through The Ultrasonic Integrated Backscatter

BACKGROUND

The ultrasound guidance of cryotherapy could be improved if changes of tissue characterization parameters during freezing could be used to monitor freezing patterns and estimate the postoperative effects after surgery.

OBJECTIVE

The ultrasonic integrated backscatter analysis holds promise as an effective method for signal analysis and characterization of thawed tissues.

MATERIALS AND METHODS

The ultrasonic integrated backscatter has been found to be an important parameter for describing the ultrasonic scattering and characterization of biological tissues. However, its potential values in the evaluation of cryosurgical effects of tissues reserved unclear so far. Here, we investigated the power spectrum of acoustic signal to estimate the ultrasound integrated backscatter in normal and freeze-thawed tissues on porcine livers in vitro.

RESULTS

The experimental results carried out at 10 MHz using weakly focused pulse-echo signal element transducer indicated that the ultrasonic integrated backscatter in normal liver tissues is 31.3±4.6 whereas it is 44.2±6.5 in several pre-frozen and then thawed tissues.

CONCLUSION

These results disclosed the good correlation between the ultrasonic integrated backscatter and microstructures of the normal or thawed tissues, and hence demonstrated that the power spectrum holds promise to be used as an effective method for the characterization of thawed tissues ultrasonic integrated backscatter, which might offer a potential pragmatic prospect for the practice of monitoring transition zone between frozen and unfrozen tissues during the surgical therapy, and evaluating postoperative effects.