Single-cell census of human tooth development enables generation of human enamel

Tooth enamel secreted by ameloblasts (AMs) is the hardest material in the human body, acting as a shield to protect the teeth. However, the enamel is gradually damaged or partially lost in over 90% of adults and cannot be regenerated due to a lack of ameloblasts in erupted teeth. Here, we use single-cell combinatorial indexing RNA sequencing (sci-RNA-seq) to establish a spatiotemporal single-cell census for the developing human tooth and identify regulatory mechanisms controlling the differentiation process of human ameloblasts. We identify key signaling pathways involved between the support cells and ameloblasts during fetal development and recapitulate those findings in human ameloblast in vitro differentiation from induced pluripotent stem cells (iPSCs). We furthermore develop a disease model of amelogenesis imperfecta in a three-dimensional (3D) organoid system and show AM maturation to mineralized structure in vivo. These studies pave the way for future regenerative dentistry.

Quality Assurance of Protocol Compliance in a Multicenter Randomized Trial Investigating the Role of Hypofractionated Comprehensive Reginal Nodal Irradiation in Node-Positive Breast Cancer (HARVEST)

PURPOSE/OBJECTIVE(S)

The HARVEST trial (NCT03829553) is a phase III, multicenter, randomized clinical trial to explore efficacy and safety of hypofractionated irradiation (HFI) involving regional nodal irradiation (RNI, including internal mammary nodes, IMN) in N+ breast cancer patients treated with mastectomy or breast conserving surgery (BCS). Current study aims to analyze the dosimetric quality assurance so as to evaluate the compliance to the trial protocol.

MATERIALS/METHODS

Eligible patients were randomly assigned (1:1) to receive conventional fractionated irradiation (CFI: 50 Gy/25Fx) or HFI (40.05 Gy/15Fx), which is delivered to ipsilateral chest wall or whole breast (CW/WB) with tumor bed boost (HFI: 10.68 Gy/4Fx; CFI: 10 Gy/5Fx) and comprehensive RNI (supra/infraclavicular nodes and IMN in each patient, lower axilla if indicated) by using IMRT technique. The plan quality was evaluated based on dose distribution, dose volume histogram (DVH) and field parameters. The target coverage, including planning target volume of CW/WB (PTV1) and tumor bed (PTV2) and doses of the organs at risk (OARs) were evaluated. The LQ model was used to convert doses of OARs in HFI group using α/β = 3 Gy (EQD23) for comparison.

RESULTS

Between Feb 21, 2019 and Feb 14, 2022, 801 patients were enrolled at 8 centers with 401 and 400 in CFI and HFI group, respectively. There were 182 patients received BCS and 387 patients were with more than three positive lymph nodes. In the CFI group, the D90 and V45 of PTV1 reached the prescribed dose in 70.6% and 96.0% of the patients, respectively. In the HFI group, the D90 and V36 of PTV1 reached the prescribed dose in 87.8% and 95.5% of the patients, respectively. When the tumor bed was irradiated, the D90 of PTV2 reached the prescribed dose in 95.6% in the CFI group and 100% in the HFI group, respectively. The mean D90 of PTV1 and PTV2 were 50.09±0.65 Gy and 60.63±0.91 Gy in CFI group while 40.11±0.56 Gy and 50.79±2.03 Gy in HFI group. For OARs constraints, protocol compliance was all above 95% (heart: 95.3%; ipsilateral lung: 95.5%; contralateral lung: 97.1%; humeral head: 98.2% and spinal cord: 100%) with no significant difference between CFI and HFI groups. For patients with left-sided breast cancer, the Dmean of the heart was 5.10±1.75 Gy vs. 4.59±1.86 Gy (EQD23) in CFI and HFI groups (p = 0.51), respectively. No significant differences in Dmean of the heart (1.45±0.71 Gy vs. 1.33±0.77 Gy (EQD23), p = 0.40) was found either between two groups in right-sided patients. The differences were significant in the Dmean of the ipsilateral lung (13.37±1.99 Gy vs. 11.17±3.50 Gy (EQD23), p<0.01), contralateral lung (0.88±0.73 Gy vs. 0.74±0.61 Gy (EQD23), p<0.01) and the ipsilateral humeral head (15.27±7.62 Gy vs. 13.05±6.19 Gy (EQD23), p<0.01) and the Dmax of spinal cord (21.40±8.82 Gy vs. 19.47±7.99 Gy (EQD23), p = 0.05) between CFI and HFI groups.

CONCLUSION

A high degree of compliance with protocol dose constraints was found for treatment plans in the HARVEST trial and doses to the most of OARs decreased in HFI group.

Single Cell RNA Sequencing Reveals Human Tooth Type Identity and Guides In Vitro hiPSC Derived Odontoblast Differentiation (iOB)

Over 90% of the U.S. adult population suffers from tooth structure loss due to caries. Most of the mineralized tooth structure is composed of dentin, a material produced and mineralized by ectomesenchyme derived cells known as odontoblasts. Clinicians, scientists, and the general public share the desire to regenerate this missing tooth structure. To bioengineer missing dentin, increased understanding of human tooth development is required. Here we interrogate at the single cell level the signaling interactions that guide human odontoblast and ameloblast development and which determine incisor or molar tooth germ type identity. During human odontoblast development, computational analysis predicts that early FGF and BMP activation followed by later HH signaling is crucial. Application of this sci-RNA-seq analysis generates a differentiation protocol to produce mature hiPSC derived odontoblasts in vitro (iOB). Further, we elucidate the critical role of FGF signaling in odontoblast maturation and its biomineralization capacity using the de novo designed FGFR1/2c isoform specific minibinder scaffolded as a C6 oligomer that acts as a pathway agonist. We find that FGFR1c is upregulated in functional odontoblasts and specifically plays a crucial role in driving odontoblast maturity. Using computational tools, we show on a molecular level how human molar development is delayed compared to incisors. We reveal that enamel knot development is guided by FGF and WNT in incisors and BMP and ROBO in the molars, and that incisor and molar ameloblast development is guided by FGF, EGF and BMP signaling, with tooth type specific intensity of signaling interactions. Dental ectomesenchyme derived cells are the primary source of signaling ligands responsible for both enamel knot and ameloblast development.

[Associations between indoor volatile organic compounds and nocturnal heart rate variability of young female adults: A panel study]

OBJECTIVE

To investigate the association between short-term exposure to indoor total volatile organic compounds (TVOC) and nocturnal heart rate variability (HRV) among young female adults.

METHODS

This panel study recruited 50 young females from one university in Beijing, China from December 2021 to April 2022. All the participants underwent two sequential visits. During each visit, real time indoor TVOC concentration was monitored using an indoor air quality detector. The real time levels of indoor temperature, relative humidity, noise, carbon dioxide and fine particulate matter were monitored using a temperature and humidity meter, a noise meter, a carbon dioxide meter and a particulate counter, respectively. HRV parameters were measured using a 12-lead Holter. Mixed-effects models were used to evaluate the association between the TVOC and HRV parameters and establish the exposure-response relationships, and two-pollutant models were applied to examine the robustness of the results.

RESULTS

The mean age of the 50 female subjects was (22.5±2.3) years, and the mean body mass index was (20.4±1.9) kg/m². During this study, the median (interquartile range) of indoor TVOC concentrations was 0.069 (0.046) mg/m³, the median (interquartile range) of indoor temperature, relative humidity, carbon dioxide concentration, noise level and fine particulate matter concentration were 24.3 (2.7) ℃, 38.5% (15.0%), 0.1% (0.1%), 52.7 (5.8) dB(A) and 10.3 (21.5) μg/m³, respectively. Short-term exposure to indoor TVOC was associated with significant changes in time-domain and frequency-domain HRV parameters, and the exposure metric for most HRV parameters with the most significant changes was 1 h-moving average. Along with a 0.01 mg/m³ increment in 1 h-moving average concentration of indoor TVOC, this study observed decreases of 1.89% (95%CI: -2.28%, -1.50%) in standard deviation of all normal to normal intervals (SDNN), 1.92% (95%CI: -2.32%, -1.51%) in standard deviation of average normal to normal intervals (SDANN), 0.64% (95%CI: -1.13%, -0.14%) in percentage of adjacent NN intervals differing by more than 50 ms (pNN50), 3.52% (95%CI: -4.30%, -2.74%) in total power (TP), 5.01% (95%CI: -6.21%, -3.79%) in very low frequency (VLF) power, and 4.36% (95%CI: -5.16%, -3.55%) in low frequency (LF) power. The exposure-response curves showed that indoor TVOC was negatively correlated with SDNN, SDANN, TP, and VLF when the concentration exceeded 0.1 mg/m³. The two-pollutant models indicated that the results were generally robust after controlling indoor noise and fine particulate matter.

CONCLUSION

Short-term exposure to indoor TVOC was associated with significant negative changes in nocturnal HRV of young women. This study provides an important scientific basis for relevant prevention and control measures.

[Incidence and prognosis of olfactory and gustatory dysfunctions related to infection of SARS-CoV-2 Omicron strain: a national multi-center survey of 35 566 population]

Objective: This cross-sectional investigation aimed to determine the incidence, clinical characteristics, prognosis, and related risk factors of olfactory and gustatory dysfunctions related to infection with the SARS-CoV-2 Omicron strain in mainland China. Methods: Data of patients with SARS-CoV-2 from December 28, 2022, to February 21, 2023, were collected through online and offline questionnaires from 45 tertiary hospitals and one center for disease control and prevention in mainland China. The questionnaire included demographic information, previous health history, smoking and alcohol drinking, SARS-CoV-2 vaccination, olfactory and gustatory function before and after infection, other symptoms after infection, as well as the duration and improvement of olfactory and gustatory dysfunction. The self-reported olfactory and gustatory functions of patients were evaluated using the Olfactory VAS scale and Gustatory VAS scale. Results: A total of 35 566 valid questionnaires were obtained, revealing a high incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain (67.75%). Females(χ2=367.013, P<0.001) and young people(χ2=120.210, P<0.001) were more likely to develop these dysfunctions. Gender(OR=1.564, 95%CI: 1.487-1.645), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), oral health status (OR=0.881, 95%CI: 0.839-0.926), smoking history (OR=1.152, 95%CI=1.080-1.229), and drinking history (OR=0.854, 95%CI: 0.785-0.928) were correlated with the occurrence of olfactory and taste dysfunctions related to SARS-CoV-2(above P<0.001). 44.62% (4 391/9 840) of the patients who had not recovered their sense of smell and taste also suffered from nasal congestion, runny nose, and 32.62% (3 210/9 840) suffered from dry mouth and sore throat. The improvement of olfactory and taste functions was correlated with the persistence of accompanying symptoms(χ2=10.873, P=0.001). The average score of olfactory and taste VAS scale was 8.41 and 8.51 respectively before SARS-CoV-2 infection, but decreased to3.69 and 4.29 respectively after SARS-CoV-2 infection, and recovered to 5.83and 6.55 respectively at the time of the survey. The median duration of olfactory and gustatory dysfunctions was 15 days and 12 days, respectively, with 0.5% (121/24 096) of patients experiencing these dysfunctions for more than 28 days. The overall self-reported improvement rate of smell and taste dysfunctions was 59.16% (14 256/24 096). Gender(OR=0.893, 95%CI: 0.839-0.951), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), history of head and facial trauma(OR=1.180, 95%CI: 1.036-1.344, P=0.013), nose (OR=1.104, 95%CI: 1.042-1.171, P=0.001) and oral (OR=1.162, 95%CI: 1.096-1.233) health status, smoking history(OR=0.765, 95%CI: 0.709-0.825), and the persistence of accompanying symptoms (OR=0.359, 95%CI: 0.332-0.388) were correlated with the recovery of olfactory and taste dysfunctions related to SARS-CoV-2 (above P<0.001 except for the indicated values). Conclusion: The incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain is high in mainland China, with females and young people more likely to develop these dysfunctions. Active and effective intervention measures may be required for cases that persist for a long time. The recovery of olfactory and taste functions is influenced by several factors, including gender, SARS-CoV-2 vaccination status, history of head and facial trauma, nasal and oral health status, smoking history, and persistence of accompanying symptoms.

Top-down design of protein architectures with reinforcement learning

As a result of evolutionary selection, the subunits of naturally occurring protein assemblies often fit together with substantial shape complementarity to generate architectures optimal for function in a manner not achievable by current design approaches. We describe a "top-down" reinforcement learning-based design approach that solves this problem using Monte Carlo tree search to sample protein conformers in the context of an overall architecture and specified functional constraints. Cryo-electron microscopy structures of the designed disk-shaped nanopores and ultracompact icosahedra are very close to the computational models. The icosohedra enable very-high-density display of immunogens and signaling molecules, which potentiates vaccine response and angiogenesis induction. Our approach enables the top-down design of complex protein nanomaterials with desired system properties and demonstrates the power of reinforcement learning in protein design.

Sci-Seq of Human Fetal Salivary Tissue Introduces Human Transcriptional Paradigms and a Novel Cell Population

Multiple pathologies and non-pathological factors can disrupt the function of the non-regenerative human salivary gland including cancer and cancer therapeutics, autoimmune diseases, infections, pharmaceutical side effects, and traumatic injury. Despite the wide range of pathologies, no therapeutic or regenerative approaches exist to address salivary gland loss, likely due to significant gaps in our understanding of salivary gland development. Moreover, identifying the tissue of origin when diagnosing salivary carcinomas requires an understanding of human fetal development. Using computational tools, we identify developmental branchpoints, a novel stem cell-like population, and key signaling pathways in the human developing salivary glands by analyzing our human fetal single-cell sequencing data. Trajectory and transcriptional analysis suggest that the earliest progenitors yield excretory duct and myoepithelial cells and a transitional population that will yield later ductal cell types. Importantly, this single-cell analysis revealed a previously undescribed population of stem cell-like cells that are derived from SD and expresses high levels of genes associated with stem cell-like function. We have observed these rare cells, not in a single niche location but dispersed within the developing duct at later developmental stages. Our studies introduce new human-specific developmental paradigms for the salivary gland and lay the groundwork for the development of translational human therapeutics.

Multivalent designed proteins neutralize SARS-CoV-2 variants of concern and confer protection against infection in mice

New variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continue to arise and prolong the coronavirus disease 2019 (COVID-19) pandemic. Here, we used a cell-free expression workflow to rapidly screen and optimize constructs containing multiple computationally designed miniprotein inhibitors of SARS-CoV-2. We found the broadest efficacy was achieved with a homotrimeric version of the 75-residue angiotensin-converting enzyme 2 (ACE2) mimic AHB2 (TRI2-2) designed to geometrically match the trimeric spike architecture. Consistent with the design model, in the cryo-electron microscopy structure TRI2-2 forms a tripod at the apex of the spike protein that engaged all three receptor binding domains simultaneously. TRI2-2 neutralized Omicron (B.1.1.529), Delta (B.1.617.2), and all other variants tested with greater potency than the monoclonal antibodies used clinically for the treatment of COVID-19. TRI2-2 also conferred prophylactic and therapeutic protection against SARS-CoV-2 challenge when administered intranasally in mice. Designed miniprotein receptor mimics geometrically arrayed to match pathogen receptor binding sites could be a widely applicable antiviral therapeutic strategy with advantages over antibodies in greater resistance to viral escape and antigenic drift, and advantages over native receptor traps in lower chances of autoimmune responses.

Cross-validation of SARS-CoV-2 responses in kidney organoids and clinical populations

Kidneys are critical target organs of COVID-19, but susceptibility and responses to infection remain poorly understood. Here, we combine SARS-CoV-2 variants with genome-edited kidney organoids and clinical data to investigate tropism, mechanism, and therapeutics. SARS-CoV-2 specifically infects organoid proximal tubules among diverse cell types. Infections produce replicating virus, apoptosis, and disrupted cell morphology, features of which are revealed in the context of polycystic kidney disease. Cross-validation of gene expression patterns in organoids reflects proteomic signatures of COVID-19 in the urine of critically ill patients indicating interferon pathway upregulation. SARS-CoV-2 viral variants alpha, beta, gamma, kappa, and delta exhibit comparable levels of infection in organoids. Infection is ameliorated in ACE2-/- organoids and blocked via treatment with de novo-designed spike binder peptides. Collectively, these studies clarify the impact of kidney infection in COVID-19 as reflected in organoids and clinical populations, enabling assessment of viral fitness and emerging therapies.

Testing telediagnostic thyroid ultrasound in Peru: a new horizon in expanding access to imaging in rural and underserved areas

PURPOSE

Thyroid ultrasound is a key tool in the evaluation of the thyroid, but billions of people around the world lack access to ultrasound imaging. In this study, we tested an asynchronous telediagnostic ultrasound system operated by individuals without prior ultrasound training which may be used to effectively evaluate the thyroid and improve access to imaging worldwide.

METHODS

The telediagnostic system in this study utilizes volume sweep imaging (VSI), an imaging technique in which the operator scans the target region with simple sweeps of the ultrasound probe based on external body landmarks. Sweeps are recorded and saved as video clips for later interpretation by an expert. Two operators without prior ultrasound experience underwent 8 h of training on the thyroid VSI protocol and the operation of the telemedicine platform. After training, the operators scanned patients at a health center in Lima. Telediagnostic examinations were sent to the United States for remote interpretation. Standard of care thyroid ultrasound was performed by an experienced radiologist at the time of VSI examination to serve as a reference standard.

RESULTS

Novice operators scanned 121 subjects with the thyroid VSI protocol. Of these exams, 88% were rated of excellent image quality showing complete or near complete thyroid visualization. There was 98.3% agreement on thyroid nodule presence between VSI teleultrasound and standard of care ultrasound (Cohen's kappa 0.91, P < 0.0001). VSI measured the thyroid size, on average, within 5 mm compared to standard of care. Readers of VSI were also able to effectively characterize thyroid nodules, and there was no significant difference in measurement of thyroid nodule size (P = 0.74) between VSI and standard of care.

CONCLUSION

Thyroid VSI telediagnostic ultrasound demonstrated both excellent visualization of the thyroid gland and agreement with standard of care thyroid ultrasound for nodules and thyroid size evaluation. This system could be deployed for evaluation of palpable thyroid abnormalities, nodule follow-up, and epidemiological studies to promote global health and improve the availability of diagnostic imaging in underserved communities.

[Analysis of components of proteins from Echinococcus granulosus cyst fluid]

OBJECTIVE

To analyze the components of proteins from Echinococcus granulosus cyst fluid using the shotgun method, and to identify the active components with potential regulatory effects for immune dysregulation diseases.

METHODS

The E. granulosus cyst fluid was collected aseptically from the hepatic cysts of patients with cystic echinococcosis, and characterized by liquid chromatography (LC) tandem mass spectrometry (MS/MS) following digestion with trypsin. The protein data were searched using the software MaxQuant version 1.6.1.0 and the cellular components, molecular functions, and biological processes of the identified proteins were analyzed using the Gene Ontology (GO) method.

RESULTS

The E. granulosus cyst fluid separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) had a relative molecular mass of 25 to 70 kDa. LS-MS/MS analysis identified 37 proteins, including 32 known proteins and 5 unknown proteins. At least 4 proteins were preliminarily found to exhibit potential regulatory effects for immune dysregulation diseases, including antigen B, glutathione-S-transferase (GST), thioredoxin peroxidase (TPX) and malate dehydrogenase (MDH). GO enrichment analysis showed that the identified proteins had 149 molecular functions and were involved in 341 biological processes.

CONCLUSIONS

E. granulosus cyst fluid has a variety of protein components, and four known proteins are preliminarily identified to be associated with immune dysregulation diseases.

F-domain valency determines outcome of signaling through the angiopoietin pathway

Angiopoietins 1 and 2 (Ang1 and Ang2) regulate angiogenesis through their similar F-domains by activating Tie2 receptors on endothelial cells. Despite the similarity in the underlying receptor-binding interaction, the two angiopoietins have opposite effects: Ang1 induces phosphorylation of AKT, strengthens cell-cell junctions, and enhances endothelial cell survival while Ang2 can antagonize these effects, depending on cellular context. To investigate the molecular basis for the opposing effects, we examined the phenotypes of a series of computationally designed protein scaffolds presenting the Ang1 F-domain in a wide range of valencies and geometries. We find two broad phenotypic classes distinguished by the number of presented F-domains: Scaffolds presenting 3 or 4 F-domains have Ang2-like activity, upregulating pFAK and pERK but not pAKT, while scaffolds presenting 6, 8, 12, 30, or 60 F-domains have Ang1-like activity, upregulating pAKT and inducing migration and vascular stability. The scaffolds with 6 or more F-domains display super-agonist activity, producing stronger phenotypes at lower concentrations than Ang1. Tie2 super-agonist nanoparticles reduced blood extravasation and improved blood-brain barrier integrity four days after a controlled cortical impact injury.

Pterocarpus marsupium extract extends replicative lifespan in budding yeast

As the molecular mechanisms of biological aging become better understood, there is growing interest in identifying interventions that target those mechanisms to promote extended health and longevity. The budding yeast Saccharomyces cerevisiae has served as a premier model organism for identifying genetic and molecular factors that modulate cellular aging and is a powerful system in which to evaluate candidate longevity interventions. Here we screened a collection of natural products and natural product mixtures for effects on the growth rate, mTOR-mediated growth inhibition, and replicative lifespan. No mTOR inhibitory activity was detected, but several of the treatments affected growth rate and lifespan. The strongest lifespan shortening effects were observed for green tea extract and berberine. The most robust lifespan extension was detected from an extract of Pterocarpus marsupium and another mixture containing Pterocarpus marsupium extract. These findings illustrate the utility of the yeast system for longevity intervention discovery and identify Pterocarpus marsupium extract as a potentially fruitful longevity intervention for testing in higher eukaryotes.

Multivalent designed proteins protect against SARS-CoV-2 variants of concern

Escape variants of SARS-CoV-2 are threatening to prolong the COVID-19 pandemic. To address this challenge, we developed multivalent protein-based minibinders as potential prophylactic and therapeutic agents. Homotrimers of single minibinders and fusions of three distinct minibinders were designed to geometrically match the SARS-CoV-2 spike (S) trimer architecture and were optimized by cell-free expression and found to exhibit virtually no measurable dissociation upon binding. Cryo-electron microscopy (cryoEM) showed that these trivalent minibinders engage all three receptor binding domains on a single S trimer. The top candidates neutralize SARS-CoV-2 variants of concern with IC 50 values in the low pM range, resist viral escape, and provide protection in highly vulnerable human ACE2-expressing transgenic mice, both prophylactically and therapeutically. Our integrated workflow promises to accelerate the design of mutationally resilient therapeutics for pandemic preparedness.

ONE-SENTENCE SUMMARY

We designed, developed, and characterized potent, trivalent miniprotein binders that provide prophylactic and therapeutic protection against emerging SARS-CoV-2 variants of concern.

Designed proteins assemble antibodies into modular nanocages

Multivalent display of receptor-engaging antibodies or ligands can enhance their activity. Instead of achieving multivalency by attachment to preexisting scaffolds, here we unite form and function by the computational design of nanocages in which one structural component is an antibody or Fc-ligand fusion and the second is a designed antibody-binding homo-oligomer that drives nanocage assembly. Structures of eight nanocages determined by electron microscopy spanning dihedral, tetrahedral, octahedral, and icosahedral architectures with 2, 6, 12, and 30 antibodies per nanocage, respectively, closely match the corresponding computational models. Antibody nanocages targeting cell surface receptors enhance signaling compared with free antibodies or Fc-fusions in death receptor 5 (DR5)-mediated apoptosis, angiopoietin-1 receptor (Tie2)-mediated angiogenesis, CD40 activation, and T cell proliferation. Nanocage assembly also increases severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudovirus neutralization by α-SARS-CoV-2 monoclonal antibodies and Fc-angiotensin-converting enzyme 2 (ACE2) fusion proteins.

Benchmark Experiment to Prove the Role of Projectile Excited States Upon the Ion Stopping in Plasmas

We report on a precision energy loss measurement and theoretical investigation of 100  keV/u helium ions in a hydrogen-discharge plasma. Collision processes of helium ions with protons, free electrons, and hydrogen atoms are ideally suited for benchmarking plasma stopping-power models. Energy loss results of our experiments are significantly higher than the predictions of traditional effective charge models. We obtained good agreement with our data by solving rate equations, where in addition to the ground state, also excited electronic configurations were considered for the projectile ions. Hence, we demonstrate that excited projectile states, resulting from collisions, leading to capture-, ionization-, and radiative-decay processes, play an important role in the stopping process in plasma.

F-domain valency determines outcome of signaling through the angiopoietin pathway

Angiopoietin 1 and 2 (Ang1 and Ang2) modulate angiogenesis and vascular homeostasis through engagement of their very similar F-domain modules with the Tie2 receptor tyrosine kinase on endothelial cells. Despite this similarity in the underlying receptor binding interaction, the two angiopoietins have opposite effects: Ang1 induces phosphorylation of protein kinase B (AKT), strengthens cell-cell junctions and enhances endothelial cell survival while Ang2 antagonizes these effects^1–4. To investigate the molecular basis for the opposing effects, we examined the protein kinase activation and morphological phenotypes produced by a series of computationally designed protein scaffolds presenting the Ang1 F-domain in a wide range of valencies and geometries. We find two broad phenotypic classes distinguished by the number of presented F-domains: scaffolds presenting 4 F-domains have Ang2 like activity, upregulating pFAK and pERK but not pAKT, and failing to induce cell migration and tube formation, while scaffolds presenting 6 or more F-domains have Ang1 like activity, upregulating pAKT and inducing migration and tube formation. The scaffolds with 8 or more F-domains display superagonist activity, producing stronger phenotypes at lower concentrations than Ang1. When examined in vivo, superagonist icosahedral self-assembling nanoparticles caused significant revascularization in hemorrhagic brains after a controlled cortical impact injury.

[Clinical observation of single-segment cervical adjacent segment disease treated with artificial cervical disc replacement]

Objective: To investigate the clinical outcomes and radiographic results of artificial cervical disc replacement (ACDR) for cervical adjacent segment disease (ASD). Methods: The clinical data of 28 patients with single-segment cervical ASD treated with ACDR in Xi 'an Honghui Hospital from December 2013 to July 2016 were retrospectively analyzed. There were 19 males and 9 females with a mean age of (46±7) years (36-63 years). Preoperative, postoperative 1 month and postoperative 24 months of clinical and radiographic outcomes were recorded and compared. The clinical outcome mainly includes Japanese orthopedic association (JOA), Neck Disability Index (NDI%), Odom score and complications. Imaging assessment mainly included range of motion (ROM) of cervical spine, surgical segment ROM, Cobb angle of surgical segment, degree of adjacent disc degeneration, heterotopic ossification, and prosthesis related image parameters. Results: In terms of clinical outcome, the average JOA score was 12.7±1.5 before surgery, 14.0±1.0 one month after surgery, 15.8±0.9 24 months after surgery, and the improvement rate of JOA was 75%±19%. The mean NDI% was 27.0%±2.8% before surgery, 20.5%±1.6% one month after surgery, and 15.3%±2.8% 24 months after surgery; the difference before and after treatment was statistically significant (F=159.101, P<0.01). Twenty patients were classified with excellent Odom score and 8 patients with good Odom score at the final follow-up. The total ROM of cervical spine, operation segment ROM, operation segment Cobb angle were all improved significantly after the operation (F=4.633, 6.063, 26.952, all P<0.05). There was a statistical difference in Miyazaki classification between adjacent discs above ACDR and below the fusion segment 24 months after surgery (μ(c)=2.12, P=0.034). The incidence of heterotopic ossification was 14.3%. The results of displacement degree of prosthesis were as follow: coronal plane (0.30±0.11) mm, sagittal plane (0.28±0.10) mm; subsidence of the prosthesis: (0.27±0.09) mm. No prosthesis loosening was observed. Conclusions: The clinical outcome of revision of cervical ASD by ACDR is satisfactory. The risk of intervertebral disc degeneration in adjacent segments is significantly lower than that of ACDF due to the presence of certain motor function postoperatively.

Designed proteins assemble antibodies into modular nanocages

Antibodies are widely used in biology and medicine, and there has been considerable interest in multivalent antibody formats to increase binding avidity and enhance signaling pathway agonism. However, there are currently no general approaches for forming precisely oriented antibody assemblies with controlled valency. We describe the computational design of two-component nanocages that overcome this limitation by uniting form and function. One structural component is any antibody or Fc fusion and the second is a designed Fc-binding homo-oligomer that drives nanocage assembly. Structures of 8 antibody nanocages determined by electron microscopy spanning dihedral, tetrahedral, octahedral, and icosahedral architectures with 2, 6, 12, and 30 antibodies per nanocage match the corresponding computational models. Antibody nanocages targeting cell-surface receptors enhance signaling compared to free antibodies or Fc-fusions in DR5-mediated apoptosis, Tie2-mediated angiogenesis, CD40 activation, and T cell proliferation; nanocage assembly also increases SARS-CoV-2 pseudovirus neutralization by α-SARS-CoV-2 monoclonal antibodies and Fc-ACE2 fusion proteins. We anticipate that the ability to assemble arbitrary antibodies without need for covalent modification into highly ordered assemblies with different geometries and valencies will have broad impact in biology and medicine.

Transport of intense particle beams in large-scale plasmas

Transport of particle beams in plasmas is widely employed in fundamental research, industry, and medicine. Due to the high inertia of ion beams, their transport in plasmas is usually assumed to be stable. Here we report the focusing and flapping of intense slab proton beams transporting through large-scale plasmas by using a recently developed kinetic particle-in-cell simulation code. The beam self-focusing effect in the simulation is prominent and agrees well with previous experiments and theories. Moreover, the beam can curve and flap like turbulence as the beam density increases. Simulation and analysis indicate that the self-generated magnetic fields, produced by movement of collisional plasmas, are the dominant driver of such behaviors. By analyzing the spatial growth rate of magnetic energy and energy deposition of injected proton beams, it is found that the focusing and flapping are significantly determined by the injected beam densities and energies. In addition, a remarkable nonlinear beam energy loss is observed. Our research might find application in inertial confinement fusion and also might be of interest to the laboratory astrophysics community.

[Characteristics and dynamics of HIV-1 subtype distribution among injected drug users in Guangzhou, 2008 - 2015]

Objective: To understand the characteristics and dynamics of individuals with HIV-1 subtype infection among injected drug users (HIV infection IDU) in Guangzhou between 2008 and 2015. Methods: HIV-1 RNAs were extracted from serum samples of the individuals that were newly diagnosed with HIV-1 infection among IDUs living in Guangzhou, between 2008 and 2015. The Pol gene segments of HIV-1 genome from these RNA samples were amplified by nested reverse transcription polymerase chain reaction (Nested-PCR) and sequenced. Subsequently, phylogenetic tree was reconstructed using both pol sequences of samples and references before the subtype of HIV-1 was determined. Distributions of HIV-1 subtypes detected in IDUs with different demographic characteristics in different years were compared. Results: A total of 437 pol gene segments were successfully obtained from 517 serum samples of HIV infection IDUs. The average age of 437 HIV infected IDUs was 37.37 years with standard deviation as 8.17 years. 51.5% (225/437) of the HIV infected IDU that registered residence were not in Guangdong. The Guangxi Registered residents were accounted for 54.2% (122/225). Proportion of subtype CRF07_BC (46.5%) appeared the highest, followed by CRF01_AE (24.3%), CRF08_BC (23.3%) and other subtypes (5.9%). The annual proportions of subtype CRF07_BC (trend χ(2)=19.703, P=0.006) and CRF08_BC (trend χ(2)=25.718, P=0.001) were significantly different. The proportion of subtype CRF07_BC decreased from 56.9% to 34.2% (trend χ(2)=15.139, P=0.000), while the proportion of CRF08_BC increased from 11.8% to 37.0% (trend χ(2)=22.577, P=0.000). The proportion of CRF08_BC was significantly higher in the HIV infected IDUs with Guangxi residence (Monte Carlo simulation of exact probability P=0.000, 99%CI: 0.000-0.000). Conclusions: CRF07_BC, CRF01_ AE and CRF08_BC were the predominant HIV-1 subtypes while multiple subtypes were co-circulated among the HIV infected IDUs in Guangzhou, between 2008 and 2015. Behavioral intervention set for HIV infected IDUs with Guangxi residence should be strengthened in Guangzhou.

[Characteristic analysis among MSM-users of the "Online HIV Acquisition Risk Assessment System" in Guangzhou]

Objective: To analyze the characteristics of levels related to the risk through self-evaluation system, among MSM users in Guangzhou, between 2015 and 2017. Methods: Between 2015 and 2017, data was collected from the users of a self-evaluation system network related to HIV infection, based on the previous 'HIV health risk appraisal model'. Information on risk factors was collected to calculate the scores and levels of risks and to estimate the incidence of HIV. Taking the reference of R value on risks as (R=0.9-1.1) in general population. The ones with very low risk, with low risk, moderate risk, high risk and very high risk were set as R≤0.5, 0.5<R≤0.9, 0.9<R≤1.1, 1.1< R≤2.0 and R>2.0, respectively. The scores of modifiable risk factors were compared with different subgroups of MSM. Results: A total of 4 601 MSM were involved in this study, with the following features presented as: aged 16-64 (28.38±7.11) years, proportions of residence from Guangzhou, Guangdong province or other provinces as 38.6%(1 776/4 601)、35.4%(1 629/4 601) and 26.0%(1 197/4 601), 59.6%(2 742/4 601) received bachelor or above degrees. 81.3%(3 741/4 601) of them claimed as having homosexual orientation. R values of risk level on very low risk, low risk level, moderate risk, high risk and very high risk appeared as 12.9%(594/4 601), 50.9%(2 342/4 601), 17.0%(783/4 601), 14.8%(682/4 601) and 4.3%(200/4 601), respectively. Scores of modifiable risk factors decreased year by year (P<0.05), among MSM in this study. In either of the groups that experiencing insertive or receptive sex, the ones with heterosexual orientation presented the highest scores of modifiable risk factors (P<0.05). Conclusions: The risk levels on HIV infections called for special attention among the users of the self-evaluation network system. Among the MSM that carrying either insertive or receptive sex role, the ones with heterosexual orientation had the highest risk levels and scores of modifiable risk factors in Guangzhou. Further study should be explored to better understand the causes of related risks.

[Status quo and characteristic analysis among MSM-users of the "Internet Plus-based AIDS Comprehensive Prevention Service System" in Guangzhou]

Objective: To analyze the characteristics of the "Interner Plus-based AIDS Comprehensive Prevention Service System" among MSM who frequently using the Internet in Guangzhou. Methods: An online survey was conducted among MSM who were recruited through gay-website portals between August and September, 2018 in Guangzhou, to collect information regarding the use of and attitudes on the "Interner Plus-based AIDS Comprehensive Prevention Service System" . Logistic regression was used to explore the association between the use of Internet intervention tools and related behavioral characteristics. Information on the awareness of AIDS, HIV testing, and condomless anal sex behavior were compared between the core or non-core services users. Results: A total of 777 Internet-based MSM were recruited as participants including 638 men (82.1%) as core service users. MSM were satisfied in using the the "Interner Plus-based AIDS Comprehensive Prevention Service System" while more than 80.0% of the users felt that the tools were helpful in: increasing the HIV awareness, promoting test uptake, and reducing those related risk behavior. Comparing with those who did not use the tools, the users showed higher rates in practising condomless anal intercourse (1.50-1.86 times), commercial sex with men (11.60-21.21 times), and unprotected vaginal intercourse (13.62-20.67 times), in the last 6 months. Proportions of core service users appeared as: [96.6% vs. 74.8%, aOR (95%CI): 8.80 (4.85-15.97)] on HIV testing, [56.4% vs. 22.3%, aOR (95%CI): 4.54 (2.94-7.02)] on regular HIV testing and [86.2% vs. 80.6%, aOR (95%CI): 1.75 (1.06-2.89)] on awareness of HIV knowledge respectively, which were all significantly higher than the non-core service users. Conclusions: The frequent Internet using MSM in Guangzhou claimed to have had high acceptance and satisfaction on the local Internet HIV intervention service tools. The "Internet Plus-based AIDS Comprehensive Prevention Service System" had effectively reached the high-risk subgroups of MSM, increasing the awareness on related risk and promoting testing on HIV.

[The efficacy and safety of salvage surgery for local recurrent nasopharyngeal carcinoma: a systematic review and Meta-analysis]

Objective: To assess the current evidence regarding the efficacy, safety, and potential advantages of endoscopic compared with open salvage surgery for patients with local recurrent nasopharyngeal carcinoma. Methods: A systematic search of Pubmed/Medline, Embase, and Cochrane databases ranged between 2000 and 2017 was conducted. Included studies reported specific residual or local recurrent nasopharyngeal cancer survival data. Proportional Meta-analysis was performed on both outcomes with a random-effects model and the 95% confidential intervals were calculated by Stata 12.0 software. Results: A total of 24 case series studies were included in the Meta-analysis.The pooled 2-year overall survival rates of endoscopic and open group were 84% (95%CI:72%-93%), 68%(95%CI:59%-77%),respectively.The pooled 2-year disease-free survival rates of endoscopic and open group were 68%(95%CI:53%-81%), 65%(95%CI:54%-75%),respectively. The pooled 5-year overall survival rates of endoscopic and open group were 72%(95%CI:37%-97%), 48% (95%CI:40%-56%),respectively.The pooled 5-year disease-free survival rates of endoscopic and open group were 65%(95%CI:29%-93%), 50%(95%CI:43%-57%),respectively.The combined outcome of endoscopic was higher than open procedure. In addition, less severe complications, lower local recurrence rates(27%vs32%).The 2-year overall survival rates of endoscopic was higher than open procedure in the staging of rT1, rT2, and rT3 (93%vs87%; 77%vs63%; 67%vs53%) , but was equal to open in the staging for rT4 (35%vs35%) .Meta-regression showed that the heterogeneity was correlated with advanced tumor ratio. Conclusions: The present Meta-analysis reveals that endoscopic approach offers a safe and efficient alternative to open approach with better short-term outcome and fewer postoperative complications in selecting patients strictly.

Analogue of dynamic Hall effect in cavity magnon polariton system and coherently controlled logic device

Cavity magnon polaritons are mixed quasiparticles that arise from the strong coupling between cavity photons and quantized magnons. Combining high-speed photons with long-coherence-time magnons, such polaritons promise to be a potential candidate for quantum information processing. For harnessing coherent information contained in spatially distributed polariton states, it is highly desirable to manipulate cavity magnon polaritons in a two-dimensional system. Here, we demonstrate that tunable cavity magnon polariton transport can be achieved by strongly coupling magnons to microwave photons in a cross-cavity. An analog to the dynamic Hall effect has been demonstrated in a planar cavity spintronic device, where the propagation of cavity-magnon-polaritons is deflected transversally due to hybrid magnon-photon dynamics. Implementing this device as a Michelson-type interferometer using the coherent nature of the dynamic Hall and longitudinal signals, we have developed a proof-of-principle logic device to control the amplitude of cavity-magnon-polaritons by encoding the input microwave phase.

Exploring photon-polariton interactions advances not only the understanding of polariton dynamics but also the modern technologies. Here the authors take advantage of strong coupled magnons and microwave photons in a cross-cavity to achieve tunable cavity magnon polariton transport which can be potentially applied as logic devices.

Particle-in-cell simulation of transport and energy deposition of intense proton beams in solid-state materials

A particle-in-cell (PIC) simulation code is used to investigate the transport and energy deposition of an intense proton beam in solid-state material. This code is able to simulate close particle interactions by using a Monte Carlo binary collision model. Such a model takes into account all related interactions between the incident protons and material particles, e.g., proton-nucleus, proton-bound-electron, and proton-free-electron collisions. This code also includes a Monte Carlo model for the collisional ionization and electron-ion recombination as well as the depression of the ionization potential by shielding of surrounding particles. Moreover, for intense proton beams, in order to include collective electromagnetic effects, significantly speed up the simulation, and simultaneously avoid numerical instabilities, an approach that combines the PIC method with a reduced model of high-density plasma based on Ohm's law is used. Simulation results indicate that the collective electromagnetic effects have a significant influence on the transport and energy deposition of proton beams. The Ohmic electric field would increase the stopping power and leads to a shortened range of proton beams in solid. The magnetic field would localize the energy deposition by collimating proton beams, which would otherwise be deflected by the collisions with nuclei.

[Long-term clinical observation of aspheric multifocal intraocular lens implantation]

Objective: To observe the clinical effect of long term visual quality after the implantation of the aspheric diffractive multifocal intraocular lens. Methods: This was a retrospective cohort study.One hundred and thirty cases of age-related cataract (170 eyes) after phacoemulsification cataract extraction combined with IOL implantation were collected from September of 2009 to January of 2011 in the First Affiliated Hospital of Zhengzhou University.There were 42 patients (57 eyes) with aspheric multifocal group, 43 patients (57 eyes) in the aspheric group and 45 patients (56 eyes) in the spherical group according to the different types of IOL implanted.At 1 year, 3 years and 5 years after operation, the following parameters were assessed: uncorrected and best corrected distance, medium and near vision acuity, contrast sensitivity, wavefront aberrations, modulation transfer functions (MTF), stereopsis, visual function and quality of life (VF/QOL) questionnaire survey. Results: At 1 year, 3 years and 5 years after operation, the uncorrected medium visual acuity in aspheric diffractive multifocal IOL group(0.30(0.10, 0.50), 0.30(0.10, 1.00), 0.30(0.10, 0.50)) was better than that of eyes in aspheric IOL group(0.40 (0.10, 0.0), 0.40 (0.20, 1.00), 0.40 (0.20, 0.50)) (Z(1)=-3.32,-1.73,-3.01, P(1)=0.00, 0.01, 0.00) and spherical IOL group (0.40(0.30, 1.00), 0.40(0.20, 1.00), 0.40(0.20, 1.00)) (Z(2)=-5.77,-3.19,-4.49, P(2)=0.00, 0.00, 0.00).And the near vision in aspheric diffractive multifocal IOL group(0.25(0.00, 1.00), 0.30(0.00, 1.00), 0.30(0.00, 1.00)) was also obviously better than that of eyes in aspheric IOL group (0.50(0.18, 1.00), 0.50(0.18, 1.00), 0.50(0.18, 1.00)) (Z(1)=-5.57,-5.37,-4.93, P(1)=0.00, 0.00, 0.00) and spherical IOL group(0.60(0.18, 1.00), 0.60(0.18, 1.00), 0.60(0.18, 1.00)) (Z(2)=-7.00,-6.91,-6.53, P(2)=0.00, 0.00, 0.00). At 5 years after operation, the mean higher-order aberration for 3.0mm and 5.0mm optical zone in aspheric diffractive multifocal IOL group (0.21(0.03, 0.46), 0.37(0.12, 2.01)) were significantly lower than that in spherical IOL group (0.43(0.10, 1.91), 0.46 (0.10, 1.91) ) (Z(2)=-4.81,-1.97, P(2)=0.00, 0.01).But there was no statistical difference between the aspheric diffractive multifocal and aspheric IOL group (0.21(0.03, 1.17), 0.34(0.06, 1.74)) (Z(1)=-0.10,-1.81, P(1)=0.92, 0.07).The mean spherical aberration for 3.0mm and 5.0mm optical zone in aspheric diffractive multifocal IOL group (0.01(-0.01, 0.20), 0.03(-0.10, 0.20)) were significantly lower than that in spherical IOL group (0.29(0.10, 0.99), 0.32(0.10, 0.99)) (Z(2)=-8.48,-8.54, P(2)=0.00, 0.01).But there was no statistical differences between the aspheric diffractive multifocal and aspheric IOL group (0.02(-0.09, 0.37), 0.04(-0.09, 0.37)) (Z(1)=-0.60,-0.73, P(1)=0.55, 0.46).About 86% of patients in aspheric diffractive multifocal IOL group do not need to wear glasses, it was better than the other two groups (χ(2)=17.83, 24.45, P=0.00, 0.00).The incidence of night glare and halo in aspheric diffractive multifocal IOL group 16/50(32%) was higher than that of aspherical IOL group 5/50(10%) and spherical IOL group 3/50(6%), and the difference was statistically significant (χ(2)=7.29, 10.98, P=0.00, 0.00).The overall satisfaction in aspheric diffractive multifocal IOL group was 45/50 (90%), better than that of aspherical IOL group 29/50(58%) and spherical IOL group 20/50(40%), and the difference was statistically significant (χ(2)=13.31, 27.47, P=0.00, 0.00). Conclusions: The aspheric diffractive multifocal IOL can provide patients with good and stable far, medium and near vision, to meet the needs of patients without glasses.At the same time, it can effectively reduce the high order aberrations and spherical aberration, improve visual quality.But due to night glare and glow, it does not apply to professional drivers and nighttime drivers. (Chin J Ophthalmol, 2017, 53: 599-609).

[Prevalence of drug resistance in treatment-naive HIV infected men who have sex with men in Guangzhou, 2008-2015]

Objective: To understand the prevalence of drug resistance in treatment-naive HIV infected men who have sex with (MSM) in Guangzhou. Methods: HIV-1 RNA were extracted from the serum specimens of the MSM newly confirmed to be HIV-1 positive, living in Guangzhou and receiving no anti-viral therapy from 2008 to 2015. HIV-1 pol gene segments, including full protease and part reverse transcriptase, were amplified by nested reverse transcription polymerase chain reaction (nested-PCR) and sequenced by Sanger. Subsequently, the sequence data were submitted to Stanford University HIV Drug Resistance Database for drug resistance analysis. Results: Among 2 283 HIV infected MSM, HIV-1 pol gene segments were obtained from the serum samples of 1 986 HIV infected MSM aged 16-84 (30.18±8.24) years. Among them, the unmarried accounted for 74.17% (1 473/1 986), those of Han ethnic group accounted for 90.64% (1 800/1 986), those with education level of college or above accounted for 49.65% (986/1 986), those with education level of senior high school or secondary school accounted for 27.14% (539/1 986), those with education level of junior high school or below accounted for 20.89% (415/1 986). The distribution of subtypes was predominated by CRF07_BC (38.22%, 759/1 986) and CRF01_AE (34.49%, 685/1 986). The overall prevalence of drug resistance was 3.32% (66/1 986). The prevalence of resistance to protease inhibitors (PIs), nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs) were 1.36%(27/1 986), 0.65% (13/1 986) and 1.61% (32/1 986), respectively. Subtype B had higher resistance to PIs, NRTIs and NNRTIs and subtype CRF55_01B had highest resistance to NNRTIs compared with other subtypes. In subtype B, the resistant rates to D4T, EFV and NVP were highest (all 4.17%, 5/120), followed by those to NFV, AZT and RPV (all 3.33%, 4/120). In subtype CRF55_01B, the resistant rates to EFV and NVP were highest (all 5.50%, 16/291), followed by those to ETR and RPV (all 5.15%, 15/291). Conclusions: The prevalence of drug resistance in treatment-naive HIV infected MSM in Guangzhou remained at low level and current antiretroviral drugs are generally effective. However, subtype B and CRF55_01B have higher drug resistance.

Metabolism as an early predictor of DPSCs aging

Tissue resident adult stem cells are known to participate in tissue regeneration and repair that follows cell turnover, or injury. It has been well established that aging impedes the regeneration capabilities at the cellular level, but it is not clear if the different onset of stem cell aging between individuals can be predicted or prevented at an earlier stage. Here we studied the dental pulp stem cells (DPSCs), a population of adult stem cells that is known to participate in the repair of an injured tooth, and its properties can be affected by aging. The dental pulp from third molars of a diverse patient group were surgically extracted, generating cells that had a high percentage of mesenchymal stem cell markers CD29, CD44, CD146 and Stro1 and had the ability to differentiate into osteo/odontogenic and adipogenic lineages. Through RNA seq and qPCR analysis we identified homeobox protein, Barx1, as a marker for DPSCs. Furthermore, using high throughput transcriptomic and proteomic analysis we identified markers for DPSC populations with accelerated replicative senescence. In particular, we show that the transforming growth factor-beta (TGF-β) pathway and the cytoskeletal proteins are upregulated in rapid aging DPSCs, indicating a loss of stem cell characteristics and spontaneous initiation of terminal differentiation. Importantly, using metabolic flux analysis, we identified a metabolic signature for the rapid aging DPSCs, prior to manifestation of senescence phenotypes. This metabolic signature therefore can be used to predict the onset of replicative senescence. Hence, the present study identifies Barx1 as a DPSCs marker and dissects the first predictive metabolic signature for DPSCs aging.

Determination of Hydrogen Density by Swift Heavy Ions

A novel method to determine the total hydrogen density and, accordingly, a precise plasma temperature in a lowly ionized hydrogen plasma is described. The key to the method is to analyze the energy loss of swift heavy ions interacting with the respective bound and free electrons of the plasma. A slowly developing and lowly ionized hydrogen theta-pinch plasma is prepared. A Boltzmann plot of the hydrogen Balmer series and the Stark broadening of the H_{β} line preliminarily defines the plasma with a free electron density of (1.9±0.1)×10^{16}  cm^{-3} and a free electron temperature of 0.8-1.3 eV. The temperature uncertainty results in a wide hydrogen density, ranging from 2.3×10^{16} to 7.8×10^{18}  cm^{-3}. A 108 MHz pulsed beam of ^{48}Ca^{10+} with a velocity of 3.652  MeV/u is used as a probe to measure the total energy loss of the beam ions. Subtracting the calculated energy loss due to free electrons, the energy loss due to bound electrons is obtained, which linearly depends on the bound electron density. The total hydrogen density is thus determined as (1.9±0.7)×10^{17}  cm^{-3}, and the free electron temperature can be precisely derived as 1.01±0.04  eV. This method should prove useful in many studies, e.g., inertial confinement fusion or warm dense matter.

[Application of " Internet Plus" AIDS prevention services among men who have sex with men in Guangzhou, China: results from 2010 to 2015]

Objective: To introduce the development strategy of " Internet Plus" AIDS prevention services and its implementation results from 2010 to 2015 in Guangzhou, China. Methods: A gay men's health column was created for an active website aimed at men who have sex with men(MSM), in collaboration with local community organizations and the Guangzhou CDC. We designed intervention tools(including scenario-based applications and HIV risk self-assessment systems)and an online HIV testing service platform, integrated with applied psychology and behavioral theory as well as the " Internet Plus" concept, to intervene in HIV infection risk factors among MSM. Data of clients who accessed the " Internet Plus" AIDS services from 2010 to 2015 were used to evaluate service operation. Six-year consecutive surveys, conducted between April and July of each service year, were collected using a national AIDS sentinel surveillance questionnaire. For each year of surveillance, information on HIV prevalence, HIV interventions received during the past year, unprotected anal intercourse in the past 6 months, and HIV testing in the past year were compared using the chi-squared(χ²)test, to roughly reflect the effect of"Internet Plus" AIDS prevention services. Results: As of 31 December 2015, a total of 34 395 MSM had received " Internet Plus" services and HIV testing. The number of MSM tested increased from 2 338 in 2010 to 8 054 in 2015. From 2010 to 2015, newly identified HIV cases in each year were 59, 166, 312, 283, 291, and 270, which accounted for 25.0%, 32.8%, 38.8%, 35.1%, 30.5%, and 23.2% of MSM HIV cases of Guangzhou, respectively. Sentinel surveillance data showed that during the study period, 3 047 MSM were investigated, with 405, 400, 401, 633, 608, and 600 each year, respectively. The proportion of participants who had received any HIV intervention during the past year was 74.3%(301), 70.8%(283), 83.3%(334), 85.0%(538), 69.1%(420), and 83.8%(503)each year, respectively(trend χ²=6.53, P=0.011). HIV testing done during the past year accounted for 44.0%(178), 44.3%(177), 49.4%(198), 53.4%(338), 56.1%(341), and 60.2%(361)each year, respectively(trend χ²=40.83, P<0.001). Unprotected anal intercourse in the past 6 months accounted for 59.3%(240), 62.0%(248), 56.6%(227), 57.0%(361), 48.4%(294), and 43.7%(262)each year, respectively(trend χ²=42.21, P<0.001). Conclusion: The"Internet Plus"AIDS prevention services in this study represent a manner to enhance traditional HIV prevention strategies. We found these services to be effective in implementation of the national AIDS control and prevention strategy, especially for the expansion of intervention, testing, and case identification among high-risk populations.

[Salvage surgical treatment for local recurrent nasopharyngeal cancer]

The salvage radiation or surgery is the main choice for recurrent nasopharyngeal cancer now. However the recurrent tumor becomes radiation insensitive and meanwhile,morbidity and mortality become higher.Recently the endoscopic salvage surgery has been developed;the collective evidence from a number of such studies suggests that endoscopic nasopharyngectomy is a safe and effective procedure for the treatment of rNPC.This article reviewed related researches about the feasibility,methods, and current situation of endoscopic salvage surgery.

[Comparison of calcar replacement arthroplasty and Intertan nail in treatment of intertrochanteric fracture in the aged]

OBJECTIVE

To compare the clinical efficacy between calcar replacement arthroplasty and InterTan nail in treatment of intertrochanteric fractures in the aged.

METHODS

From January 2008 to July 2013, a total of 58 elderly patients with intertrochanterie fracture , had been treated in Department of Orthopaedics, Tianjin Occupational Diseases Control and Treatment Hospital, were retrospectively compared.Half of them were treated with calcar replacement arthroplasty and half with InterTan nails.In the calcar replacement arthroplasty group, there were 8 men and 21 women, with an average age of (85.3±4.9) years, there were 8 A1, 16 A2 and 5 A3 fractures according to the AO classification.In the InterTan nail group, there were 10 men and 19 women, with an average age of (86.1±5.6) years, there were 11 A1, 15 A2 and 3 A3 fractures according to the AO classification.The 2 groups were compared in terms of the duration of the operation, intraoperative blood loss, hospitalization time, time of off-bed activity, complications, mortality rate, Harris hip score, short form 36 questionnaire score and ADL score.

RESULTS

Twenty-seven patients in the calcar replacement arthroplasty group and twenty-six patients in the patients in each group were followed up InterTan nail group were follow-up for a period of 24 months.There were no significant differences between the 2 groups regarding hospitalization time, complications, mortality rate, Harris hip score, short form 36 questionnaire score and ADL score(P>0.05). However, the operative time, intraoperative blood loss, and the time of off-bed activity for the calcar replacement arthroplasty and InterTan nail groups was respectively (78±29) minutes vs (59±32) minutes, (316±185) ml vs (108±97) ml, and (15±5.8) days vs (32±12.7) days, all of them with a significant difierence(P<0.05).

CONCLUSION

The patients in the calcar replacement arthroplasty group suffered longer operative time and more blood loss, but they can obtain early off-bed activity.The hospitalization time, complications, mortality rate, hip function and quality of Life between the two were the same.

Association of polymorphism in ICAM-1 (K469E) and cytology parameters in patients' initial blood test with acute ischemic stroke

Acute ischemic stroke (AIS) has become a serious health problem in many countries because of its poor outcome and worsening epidemic trend. Early identification of genetic risk factors and physiological indicators for stroke occurrence may help to reduce the incidence of stroke. Therefore, we conducted a case-control study including 50 AIS patients and 50 healthy individuals from a Chinese population to explore the association between AIS and patient complete blood profiles and the association between AIS and the genetic polymorphism K469E in intercellular adhesion molecule-1 (ICAM-1). Compared to the control group, AIS patients showed a high percentage of mononuclear cells, low platelet count, low ratio of platelet to lymphocyte count, high frequency of the 469K allele, and low frequency of the 469E allele. White blood cell count, percentage of neutrophils, percentage of lymphatic cells, platelet distribution width, mean platelet volume, and platelet hematocrit levels showed no significant differences between the 2 groups and between different genotypes. Our results suggested an association of elevated levels of mononuclear cells and reduced platelet count with higher AIS risk. Our results also supported the hypothesis that the KK genotype at the K469E locus in ICAM-1 is a risk factor for AIS.

Size-dependent elastic moduli and vibrational properties of fivefold twinned copper nanowires

Based on atomistic simulations, the elastic moduli and vibration behaviors of fivefold twinned copper nanowires are investigated in this paper. Simulation results show that the elastic (i.e., Young's and shear) moduli exhibit size dependence due to the surface effect. The effective Young's modulus is found to decrease slightly whereas the effective shear modulus increases slightly with the increase in the wire radius. Both moduli tend to approach certain values at a larger radius and can be suitably described by core-shell composite structure models. Furthermore, we show by comparing simulation results and continuum predictions that, provided the effective Young's and shear moduli are used, classic elastic theory can be applied to describe the small-amplitude vibration of fivefold twinned copper nanowires. Moreover, for the transverse vibration, the Timoshenko beam model is more suitable because shear deformation becomes apparent.

The beneficial effect of n-3 polyunsaturated fatty acids on doxorubicin-induced chronic heart failure in rats

This study was designed to assess the effects of dietary supplementation with n-3 polyunsaturated fatty acids (PUFA) from fish oil on the response of doxorubicin-induced chronic heart failure in rats. Male Sprague-Dawley rats were treated daily for 8 weeks with normal saline or n-3 PUFA intragastrically after induction of myocardial injury by intraperitoneal injection of doxorubicin 2 mg/kg once weekly for 8 weeks. Cardiac function was assessed by echocardiography. The cytoprotective role of n-3 PUFA against doxorubicin-induced myocardial injury was demonstrated by light microscopy, and serum cytokines (tumour necrosis factor-alpha and interleukin-10) were analysed by enzyme-linked immunosorbent assay. Doxorubicin induced death, alterations in echocardiography parameters and histological damage, all of which are features that characterize heart failure. There were significant differences between the doxorubicin-induced heart failure group and the n-3 PUFA-treated group in terms of echocardiography parameters and cytokine changes. Thus, dietary supplementation with n-3 PUFA attenuated doxorubicin-induced cardiac dysfunction, an effect that might be associated with recovery from an imbalance of the cytokine network.

Effects of n-3 Polyunsaturated Fatty Acid Therapy on Plasma Inflammatory Markers and N-Terminal Pro-brain Natriuretic Peptide in Elderly Patients with Chronic Heart Failure

Several previous studies have suggested that n-3 polyunsaturated fatty acids ( n-3 PUFA) can exert favourable effects in patients with heart failure, but the mechanisms involved are not fully understood. This study was designed to investigate the effects of n-3 PUFA on circulating inflammatory markers and N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients with heart failure. Seventy-six patients with heart failure were randomly assigned to receive 2 g/day of n-3 PUFA or placebo for 3 months. Treatment with n-3 PUFA significantly decreased plasma levels of tumour necrosis factor, interleukin-6, intercellular adhesion molecule 1 and NT-proBNP. Left ventricular ejection fraction showed a small, non-significant improvement. High-sensitivity C-reactive protein levels decreased significantly in smokers after n-3 PUFA treatment. Thus, n-3 PUFA can reduce levels of plasma inflammatory markers and NT-proBNP as biomarkers of risk stratification in patients with heart failure. n-3 PUFA may offer a novel therapy for heart failure.

Disinfection of maxillofacial silicone elastomer using a novel antimicrobial agent: recombinant human beta-defensin-3

Maxillofacial silicone elastomer, when used as a prosthesis, is in contact with wound surfaces and mucosa, and tends to be contaminated with microorganisms from a patient's saliva and blood. The aim of the study was to evaluate the efficacy of human beta-defensin-3 (HBD3) on the reduction of two resistant bacteria species from the surface of maxillofacial silicone elastomer. HBD3 cDNA was amplified from total RNA, which had been extracted from human gingival epithelium by means of reverse-transcription polymerase chain reaction (RT-PCR). Following this, the cDNA fragments were recombined in a prokaryotic expression vector. The constructed expression vectors pET-32a/HBD3 were transformed into Escherichia coli to obtain recombinant protein. After protein purification and refolding, the product was verified in classic antimicrobial experiments against Staphylococcus aureus and Candida albicans. Specimens made of silicone elastomer A-2186, which had been contaminated with S. aureus or C. albicans, were immersed in rHBD3 or 5.25% sodium hypochlorite (a positive control) for 5 min, 10 min, 30 min, or 60 min. The active recombinant HBD3 obtained in the current study eliminated the S. aureus and C. albicans microorganism from the surface of the maxillofacial elastomer after a 30-min immersion. There was no statistically significant difference between the rHBD3 group and the sodium hypochlorite 5.25% group. In conclusion, rHBD3 exhibits antibacterial activity against oral pathogenic strains that adhere to maxillofacial elastomer, and may, thus, contribute to the prevention of infections caused by S. aureus and C. albicans.

2-Deoxyglucose-induced long-term potentiation of monosynaptic IPSPs in CA1 hippocampal neurons

In previous experiments on excitatory synaptic transmission in CA1, temporary (10-20 min) replacement of glucose with 10 mM 2-deoxyglucose (2-DG) consistently caused a marked and very sustained potentiation (2-DG LTP). To find out whether 2-DG has a similar effect on inhibitory synapses, we recorded pharmacologically isolated mononosynaptic inhibitory postsynaptic potentials (IPSPs; under current clamp) and inhibitory postsynaptic currents (IPSCs; under voltage clamp); 2-DG was applied both in the presence and the absence of antagonists of N-methyl-D-aspartate (NMDA). In spite of sharply varied results (some neurons showing large potentiation, lasting for >1 h, and many little or none), overall there was a significant and similar potentiation of IPSP conductance, both for the early (at approximately 30 ms) and later (at approximately 140 ms) components of IPSPs or IPSCs: by 35.1 +/- 10.25% (mean +/- SE; for n = 24, P = 0.0023) and 36.5 +/- 16.3% (for n = 19, P = 0.038), respectively. The similar potentiation of the early and late IPSP points to a presynaptic mechanism of LTP. Overall, the LTP was statistically significant only when 2-DG was applied in the absence of glutamate antagonists. Tetanic stimulations (in presence or absence of glutamate antagonists) only depressed IPSPs (by half). In conclusion, although smaller and more variable, 2-DG-induced LTP of inhibitory synapses appears to be broadly similar to the 2-DG-induced LTP of excitatory postsynaptic potentials previously observed in CA1.

2-Deoxyglucose-induced long-term potentiation in CA1 is not prevented by intraneuronal chelator

In hippocampal slices, temporary (10-20 min) replacement of glucose with 10 mM 2-deoxyglucose is followed by marked and very sustained potentiation of EPSPs (2-DG LTP). To investigate its mechanism, we examined 2-DG's effect in CA1 neurons recorded with sharp 3 M KCl electrodes containing a strong chelator, 50 or 100 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA). In most cases, field EPSPs were simultaneously recorded and conventional LTP was also elicited in some cells by tetanic stimulation of stratum radiatum. 2-DG potentiated intracellular EPSP slopes by 48 +/- 5.1% (SE) in nine cells recorded with plain KCl electrodes and by 52 +/- 6.2% in seven cells recorded with EGTA-containing electrodes. In four of the latter cells, tetanic stimulation (twice 100 Hz for 1 s) failed to evoke LTP (2 +/- 1.1%), although field EPSPs were clearly potentiated (by 28 +/- 6.9%). Thus unlike tetanic LTP, 2-DG LTP is not readily prevented by postsynaptic intraneuronal injection of EGTA. These findings agree with other evidence that the rise in postsynaptic (somatic) [Ca(2+)](i) caused by 2-DG is not the principal trigger for the subsequent 2-DG LTP and that it may be a purely presynaptic phenomenon.

2-Deoxy-D-glucose-induced changes in membrane potential, input resistance, and excitatory postsynaptic potentials of CA1 hippocampal neurons

Temporary block of glycolysis by 2-deoxy-D-glucose (2-DG) reversibly suppresses synaptic transmission in the CA1 region of hippocampal slices. Recovery of responses is followed by a sustained potentiation of field excitatory postsynaptic potentials (EPSPs) (2-DG-LTP). To investigate the mechanisms involved in this type of LTP, we studied the effects of 2-DG on membrane properties of CA1 neurons (in slices from Sprague-Dawley rats), recorded with sharp intracellular electrodes containing 3 M KCl, as well as patch electrodes, filled mainly with 150 mM KMeSO4 and Hepes. The predominant change produced by 15- to 20-min applications of 2-DG (10 mM, replacing glucose) was hyperpolarization (-5.6 +/- 1.1 mV for 18 intracellular recordings and -7.2 +/- 0.80 mV for 17 whole-cell recordings) accompanied by a fall in resistance (-33 +/- 2.5% for 14 intracellular recordings and -11.6 +/- 7.1% for 15 whole-cell recordings). Virtually identical hyperpolarizations were recorded in the presence of 20 microM glyburide (-5.5 +/- 1.5 mV, n = 6), but they were abolished by adenosine antagonists 8-(p-sulfophenyl)theophylline (8-SPT) and 8-cyclopentyl-3,7-dihydro-1,3-dipropyl-1H-purine-2,6-dione (DPCPX) (2.8 +/- 1.6 and 4.0 +/- 1.7 mV, respectively; n = 5 for both). It was concluded that the hyperpolarization is most likely caused by an increase in K+ conductance, activated by a 2-DG-induced rise in adenosine release. After such applications of 2-DG, a sustained potentiation of EPSPs (similar to the 2-DG-LTP of field EPSPs) was evident in five neurons recorded with intracellular electrodes but not in any of nine whole-cell recordings, where it was replaced by sustained, LTD-like depression. We conclude that a factor essential for 2-DG-LTP induction is lost during whole-cell recording.

[Distribution of obese protein in the mouse tissue]

In the present study, the contents of obese protein of tissue from liver, brain, abdominal wall fat, skeletal muscle and the contents of plasma OP of mice were measured with radio immunoassay. The results showed that the contents of OP were much higher in the brain than that in the abdominal wall fat tissue (P < 0.01). The liver and the skeletal muscle tissue did not show the presence of OP. The contents of OP of abdominal wall fat tissue were lower in the female than that in the male mice (P < 0.05).

Vasodilator effect of human adrenomedullin(13-52) on hypertensive rats

Human adrenomedullin (hADM) is a newly isolated peptide with hypotensive activity in normotensive rats. The objective of this study was to investigate the effect of hADM(13-52) on hypertensive animals. hADM(13-52) induced a dose-dependent decrease in the blood pressure of spontaneously hypertensive rats and renal hypertensive rats. This result suggests that hADM is a novel antihypertensive peptide. In isolated rat aortic arteries, hADM(13-52) produced nitric oxide dependent relaxation and inhibited endothelin 1 and angiotensin II release. These in vitro effects may represent the molecular mechanisms underlying the hypotensive action of hADM in vivo.

[A study on hypotensive mechanism of adrenomedullin (13-52)]

In the present study the hypotensive mechanism of AdM (13-52) was investigated in rats, both in vitro and in vivo. It was found that the hypotensive effect of AdM (13-52) could be partially inhibited by L-NG-nitro-arginine (LNNA), an inhibitor of nitric oxide synthase. The vasodilator effect of AdM (13-52) was dependent on vascular endothelium and inhibited by LNNA in a dose-dependent manner. This LNNA induced inhibitory effect could be reversed with L-Arginine. In addition, the vasodilator effect of AdM (13-52) disappeared with methylene blue (MB), which blocked cGMP formation. Using radioimmunoassay it was shown that LNNA lowered, but AdM (13-52) elevated the vascular cGMP content, while vascular cGMP content was not altered by co-application of AdM (13-52) and LNNA. The above results suggest that the vasodilator effect of AdM (13-52) might be mediated by nitric oxide.

Involvement of nitric oxide in the vasodilator and depressor effect of calcitonin gene-related peptide

In present study, we examined the effects of NG-nitro-L-arginine (LNNA), an inhibitor of nitric oxide synthase (NOS), and/or methylene blue (MB), a blocker of guanylate cyclase on the vasodilator response of isolated rat arteries including aorta and mesenteric artery to calcitonin gene-related peptide (CGRP) by in vitro vasoconstriction experiment, and the effect of LNNA on the depressor action of CGRP by in vivo hemodynamic experiment. Furthermore, the effect of CGRP on NOS activity and cyclic guanylate monophosphate (cGMP) content were also examined by NOS activity assay and radioimmunoassay (RIA), respectively. The results showed that LNNA and/or MB significantly decreased, but not abolished, the vasodilator response of isolated rat aorta and mesenteric artery to CGRP. The depressor effect of CGRP on LNNA-induced hypertensive rats (LHR) was obviously weaker than that on spontaneously hypertensive rats (SHR), renal hypertensive rats (RHR) and normotensive rats (NWR). In addition, CGRP (0.5 nmol/kg) increased the NOS activity of rat aorta tissue by 1.3 times (P < 0.05) and resulted in an increase of cGMP content of aorta (1.27 times, P < 0.05) and myocardium (1.38 times, P < 0.05). The results suggested that NO is involved in the action of CGRP.

[A clinical and basic study on the relationship between acute myocardial infarction and endothelin]

The level of plasma endothelin (ET) was studied in 40 cases with acute myocardial infarction (AMI) with radioimmunoassay. The results showed that plasma ET level reached its peak value (46.01 +/- 1.64 pg/ml) immediately after AMI attack and dropped down (39.37 +/- 0.47 pg/ml) on the first day; The value was still high (15.56 +/- 1.40 pg/ml) on the twenty-eight day: this was significant higher than that in control group (6.35 +/- 0.44 pg/ml, P < 0.001). It was found that height of plasma ET level was closely correlated with severity of myocardial damage and degree of cardiac insufficiency. In order to evaluate the pathogenic role of ET in AMI, the effect of ET-antiserum on myocardial infarction (MI) was investigated on infarct model produced by ligature of left anterior descending coronary artery in rats. The results showed that plasma ET levels elevated significantly in rats with MI (8.4 +/- 1.0, sham 3.1 +/- 0.2 pg/ml, P < 0.01) and ET-antiserum administration dramatically decreased plasma ET level 65% (P < 0.01), lowered plasma content of lipid peroxide 27% (P < 0.01) and reduced infarct size 48% (P < 0.01). It is suggested that ET is an important factor which contributes to the pathogenesis of MI. Limb ischemia and reperfusion study was carried out in rats also. Metallothionein (MT) was found to antagonize markedly ET-induced vasoconstriction and lower the release of ET stimulated by angiotensin II in a dose-dependent manner. It is suggested that under certain pathological conditions MT may exert its injury--resistant and cell protective action.

[Immunohistochemical study on human papillomavirus infection of the vulva]

Two hundred and sixteen cases of human papillomavirus infection of the vulva from 1984 to 1991 in the Affiliated Hospital of Qingdao Medical College were reviewed, and were immunohistochemically studied by ABC method to detect HPV-Ag. The results showed that the demonstration of diagnostic koilocytes is very important in diagnosis of HPV infection in routine tissue slides examination. But in cases of atypical morphological changes; when diagnostic koilocytes were not formed in early stage, the demonstration of brown color granules in the nuclei of prickle cells is very diagnostic for positive HPV infection. In occasional cases, the diagnostic koilocytes do not demonstrate brown color granules in their nuclei. The explanation is that HPV-Ag was exhausted during metabolism. Besides, the cell membrane of basal cells are stained with brown color granules, while the morphological changes of upper layers of squamous epithelium have not appeared yet, therefore, there were no HPV-Ag positive reactive cells. It is probably showed that the HPV-Ag is primarily formed and appeared in the cell membrane of basal cells.