Excitation functions for fast neutron induced reactions on iron and lead

Cross sections of the 54Fe(n,p)54Mn, 54Fe(n,α)51Cr, 56Fe(n,p)56Mn and 204Pb (n,2n)203Pb reactions induced by D-T neutrons were obtained with activation method and γ-ray spectrometry technique. Experimental values measured in this work are consistent with most of the previous literature data. These reactions cross sections were theoretically calculated by using the TALYS-1.96 and EMPIRE-3.2.3 codes from threshold up to 20 MeV, and significant discrepancies were found between calculated results and experiment data. In addition, experimental values are compared with evaluated nuclear data of the CENDL-3.2, ENDF/B-VIII.0, JENDL-5, BROND-3.1 and JEFF-3.3 libraries, and significant difference was found for the 54Fe(n,α)51Cr reaction in ENDF/B-VIII.0 library but not for other reactions.

Diagnosis and treatment of recurrent patellar dislocation with knee extensor device combined with rearrangement

OBJECTIVE

This study aimed to investigate the clinical effects of combining knee extension mechanism (EM) with rearrangement in the treatment of recurrent patellar dislocation (RPD).

PATIENTS AND METHODS

Eighty-four patients with RPD admitted to the First Affiliated Hospital of Kunming Medical University were included. In this work, all patients received routine computed tomography (CT) examinations. In addition, the evaluation factors of EM combined with rearrangement therapy in RPD patients were analyzed using logistic regression.

RESULTS

Lysholm and Kujula scores, femoral canal width, patellar canal width, patellar tilt angle (PTA), and lateral patellar displacement (LPD) were significantly increased at 1 and 3 years after treatment (p < 0.05). LPA was significantly decreased, while the tibial tuberosity trochlear groove of the femur (TT-TG) demonstrated no considerable differences (p > 0.05). The good rate of the short-term Insall-Salvati index was 78.6%, and that of the long-term Insall-Salvati index was 76.1%. The combination of the knee extension device and rearrangement therapy has a higher rate of short-term and long-term Insall-Salvati index (ISI) excellence. In addition, the range of motion of the knee joint increased significantly, and the Q Angle decreased significantly (p < 0.05). Logistic regression analysis showed that age and ISI were highly correlated with the evaluation of therapeutic effects in patients with RPD.

CONCLUSIONS

EM combined with rearrangement in the treatment of RPD had positive short-term and long-term efficacy, high application value, and age, which can be popularized in clinical applications and have positive diagnostic value.

The spatio-temporal expression analysis of parathyroid hormone like hormone gene provide a new insight for bone growth of the antler tip tissue in sika deer

Objective

Parathyroid hormone like hormone (PTHLH), as an essential factor for bone growth, is involved in a variety of physiological processes. The aim of this study was to explore the role of PTHLH gene in the growth of antlers.

Methods

The coding sequence (CDS) of PTHLH gene cDNA was obtained by cloning in sika deer (Cervus nippon), and the bioinformatics was analyzed. The quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the differences expression of PTHLH mRNA in different tissues of the antler tip at different growth periods (early period, EP; middle period, MP; late period, LP).

Results

The CDS of PTHLH gene was 534bp in length and encoded 177 amino acids. Predictive analysis results revealed that the PTHLH protein was a hydrophilic protein without transmembrane structure, with its secondary structure consisting mainly of random coil. The PTHLH protein of sika deer had the identity of 98.31%, 96.82%, 96.05% and 94.92% with Cervus canadensis, Bos mutus, Oryx dammah and Budorcas taxicolor, which were highly conserved among the artiodactyls. The qRT-PCR results showed that PTHLH mRNA had a unique spatio-temporal expression pattern in antlers. In the dermis, precartilage, and cartilage tissues, the expression of PTHLH mRNA was extremely significantly higher in MP than in EP, LP (p<0.01). In the mesenchyme tissue, the expression of PTHLH mRNA in MP was significantly higher than that of EP (p<0.05), but extremely significantly lower than that of LP (p<0.01). The expression of PTHLH mRNA in antler tip tissues at all growth periods had approximately the same trend, that is, from distal to basal, it was first down-regulated from the dermis to the mesenchyme and then continuously up-regulated to the cartilage tissue.

Conclusion

PTHLH gene may promote the rapid growth of antler mainly through its extensive regulatory effect on the antler tip tissue.

Fast neutron induced reaction cross sections on natural manganese and tantalum

The cross sections for the 55Mn(n,2n)54Mn, 181Ta(n,2n)180gTa, and 181Ta(n,p)181Hf reactions were measured to be 705.1 ± 26.1 mb at 14.0 MeV, 1362.7 ± 87.2 mb at 13.6 MeV, and 2.31 ± 0.09 mb at 13.6 MeV, respectively, by using an off-line γ-ray spectroscopic technique. The neutrons were produced via the 3H(d,n)4He reaction. The monitor reactions 27Al(n,α)24Na and 93Nb(n,2n)92mNb were used for neutron flux determination. The results from the present work were compared with those of the literature and the evaluated data from ENDF/B-VIII.0, JEFF-3.3, JENDL-5, CENDL-3.2, and BROND-3.1 libraries. Besides, the cross sections were also estimated with the TALYS-1.96 nuclear model code using different level density models for a better description of the present work and literature data. The present experimental results were found to be in good agreement with most of the available literature data and with the evaluated data.

Quantitative patient graph analysis for transient ischemic attack risk factor distribution based on electronic medical records

A transient ischemic attack (TIA) affects millions of people worldwide. Although TIA risk factors have been identified individually, a systemic quantitative analysis of all health factors relevant to TIA using electronic medical records (EMR) remains lacking. This study employed a data-driven approach, leveraging hospital EMR data to create a TIA patient health factor graph. This graph consisted of 737 TIA and 737 control patient nodes, 740 health factor nodes, and over 33,000 relations between patients and factors. For all health factors in the graph, the connection delta ratios (CDRs) were determined and ranked, generating a quantitative distribution of TIA health factors. A literature review confirmed 56 risk factors in the distribution and unveiled a potential new risk factor "rhinosinusitis" for future validation. Moreover, the patient graph was visualized together with the TIA knowledge graph in the Unified Medical Language System. This integration enables clinicians to access and visualize patient data and international standard knowledge within a unified graph. In conclusion, graph CDR analysis can effectively quantify the distribution of TIA risk factors. The resulting TIA risk factor distribution might be instrumental in developing new risk prediction machine learning models for screening and early detection of TIA.

Measurement and analysis of leakage neutron spectra from Lead slab samples with D-T neutrons

The leakage neutron spectra from three different sizes of Lead samples were measured by a TOF technique at 60° and 120°. The essential characteristic properties of the experimental measurement spectra can be reproduced well by MCNP code simulations with the ENDF/B-VIII.0, CENDL-3.2, JENDL-5.0, JEFF-3.3 and TENDL-2021 evaluated nuclear data libraries. The calculated results of JENDL-5.0 and JEFF-3.3 libraries agree better with the experimental data in the whole energy range. The results from ENDF/B-VIII.0 and CENDL-3.2 are overestimated in the 4-9 MeV range at 60° and in the 4-12.5 MeV range at 120°. The differences of the leakage neutron spectra by MCNP simulations using five evaluated nuclear data libraries mainly originate from the differences of the spectrum distributions of neutron reaction channels in these libraries. And the secondary neutron energy distribution and angular distribution from the five libraries have been present to explain it.

Haplotype-resolved Genome of Sika Deer Reveals Allele-specific Gene Expression and Chromosome Evolution

Despite the scientific and medicinal importance of diploid sika deer (Cervus nippon), its genome resources are limited and haplotype-resolved chromosome-scale assembly is urgently needed. To explore mechanisms underlying the expression patterns of the allele-specific genes in antlers and the chromosome evolution in Cervidae, we report, for the first time, a high-quality haplotype-resolved chromosome-scale genome of sika deer by integrating multiple sequencing strategies, which was anchored to 32 homologous groups with a pair of sex chromosomes (XY). Several expanded genes (RET, PPP2R1A, PPP2R1B, YWHAB, YWHAZ, and RPS6) and positively selected genes (eIF4E, Wnt8A, Wnt9B, BMP4, and TP53) were identified, which could contribute to rapid antler growth without carcinogenesis. A comprehensive and systematic genome-wide analysis of allele expression patterns revealed that most alleles were functionally equivalent in regulating rapid antler growth and inhibiting oncogenesis. Comparative genomic analysis revealed that chromosome fission might occur during the divergence of sika deer and red deer (Cervus elaphus), and the olfactory sensation of sika deer might be more powerful than that of red deer. Obvious inversion regions containing olfactory receptor genes were also identified, which arose since the divergence. In conclusion, the high-quality allele-aware reference genome provides valuable resources for further illustration of the unique biological characteristics of antler, chromosome evolution, and multi-omics research of cervid animals.

DNA methylation pattern and mRNA expression of OPN promoter in sika deer antler tip tissues

In order to explore the biological role of OPN gene during the growth of sika deer antler, the dermis, mesenchyme, precartilage and cartilage tissues of sika deer antler tip at the early period of the antler with a saddle-like appearance (30 days), the rapid growth period of the antler with two branches (60 days), and the final period of the antler with three branches (90 days) were analyzed. Bisulfite sequencing PCR (BSP) and quantitative real-time PCR (qRT-PCR) were used to explore the DNA promoter methylation and mRNA expression of OPN in sika deer antler from the perspective of space and time. The test results showed that: 1) The methylation rates of OPN promoter at the early, middle and late periods of dermis tissue were (40.48±0.82)%, (40.00±1.43)%, and (39.05±0.82)%; The methylation rates in mesenchyme tissue were (37.62±0.82)%, (34.76±2.18)%, and (38.57±1.43)%; The methylation rates in precartilage tissue were (36.67±0.28)%, (29.52±1.65)%, (28.10±2.18)%; The methylation rates in cartilage tissue were (31.90±1.65)%, (26.67±1.65)%, (24.29±1.43)%. 2) There are 7 CpG sites in the OPN promoter region, and the 3 CpG sites of -367 bp, -245 bp and -31 bp are all methylated to different level. 3) The methylation level of OPN in the dermis, mesenchyme, precartilage and cartilage tissues decreased in sequence at the same growth period. At the middle and late periods, the methylation level of the promoter region of the precartilage tissue was significantly different from that of the dermis and mesenchyme tissues (P<0.05); At different growth periods, the methylation level of the promoter region of cartilage tissue was extremely significantly different from that of dermis and mesenchyme tissues (P<0.01); In the same tissue, the methylation level of the promoter region at the middle period was down-regulated compared with the early period, and the methylation level of the promoter region at the early period and the middle period was extremely significantly different in the precartilage and cartilage (P<0.01). 4) OPN mRNA is highly expressed in precartilage and cartilage tissues. 5) The methylation level of OPN promoter was negatively correlated with mRNA expression level. In summary, it is speculated that the OPN gene, which may be regulated by the DNA methylation level of the promoter, promotes the growth and development of deer antler mainly by regulating the growth of precartilage and cartilage tissues.

Activation cross sections for reactions induced by 14 MeV neutrons on natural titanium

Cross sections for the neutrons around 14 MeV interaction with natural titanium were precisely measured by neutron activation and off-line measurement technique. The fast neutrons were produced by ³H(d,n)⁴He reaction and the neutron energy was obtained by using the cross section ratio method of ⁹⁰Zr(n,2n)⁸⁹Zr to ⁹³Nb(n,2n)^92mNb reactions. Experimental cross sections have been acquired for ^natTi(n,x)⁴⁶Sc, ^natTi(n,x)⁴⁷Sc, ⁵⁰Ti(n,x)⁴⁷Ca and ⁴⁸Ti(n,x)⁴⁸Sc reactions. The measured cross section data are compared with the experimental data available in the previous literature and evaluated nuclear data from the ENDF/B-VIII.0, JEFF-3.3, JENDL-5, BROND-3.1, CENDL-3.2 and FENDL-3.2b libraries. Furthermore, excitation functions for these reactions were calculated by using the theoretical model based on Talys-1.96 code with default and adjusted parameters. Within experimental error, evaluated nuclear data are mostly consistent with experimental data. The excitation function with adjusted parameters can roughly reproduce the experimental data.

Building Practical Risk Prediction Models for Nasopharyngeal Carcinoma Screening with Patient Graph Analysis and Machine Learning

BACKGROUND

To expand nasopharyngeal carcinoma (NPC) screening to larger populations, more practical NPC risk prediction models independent of Epstein-Barr virus (EBV) and other lab tests are necessary.

METHODS

Patient data before diagnosis of NPC were collected from hospital electronic medical records (EMR) and used to develop machine learning (ML) models for NPC risk prediction using XGBoost. NPC risk factor distributions were generated through connection delta ratio (CDR) analysis of patient graphs. By combining EMR-wide ML with patient graph analysis, the number of variables in these risk models was reduced, allowing for more practical NPC risk prediction ML models.

RESULTS

Using data collected from 1,357 patients with NPC and 1,448 patients with control, an optimal set of 100 variables (ov100) was determined for building NPC risk prediction ML models that had, the following performance metrics: 0.93-0.96 recall, 0.80-0.92 precision, and 0.83-0.94 AUC. Aided by the analysis of top CDR-ranked risk factors, the models were further refined to contain only 20 practical variables (pv20), excluding EBV. The pv20 NPC risk XGBoost model achieved 0.79 recall, 0.94 precision, 0.96 specificity, and 0.87 AUC.

CONCLUSIONS

This study demonstrated the feasibility of developing practical NPC risk prediction models using EMR-wide ML and patient graph CDR analysis, without requiring EBV data. These models could enable broader implementation of NPC risk evaluation and screening recommendations for larger populations in urban community health centers and rural clinics.

IMPACT

These more practical NPC risk models could help increase NPC screening rate and identify more patients with early-stage NPC.

Valgus-varus deformity induced abnormal tissue metabolism, inflammatory damage and apoptosis in broilers

1. This study explored the tissue metabolic status and the relationship with inflammation in valgus-valgus deformity (VVD) broilers with increasing age.2. Tissue and blood from VVD and healthy broilers were collected at two, four and five weeks old. A fully automated biochemical analyser, real-time PCR, HE staining and enzyme-linked immunosorbent assay were used to detect tissue metabolic indexes, mRNA levels of inflammation and apoptosis cytokines in immune organs, histological changes and serum inflammation and immune-related protein contents in VVD broilers.3. The results showed that VVD increased the levels of total protein, albumin, alanine aminotransferase at five weeks of age, aspartate aminotransferase, urea and creatine kinase in blood at two weeks of age. It upregulated the gene expression of inflammatory factors IL-1β, IL-6, IL-8, TNF-α, NF-κB and TGF-β and apoptotic factors FAS, Bcl-2, caspase-3 and 9 in immune organs; increased levels of serum proteins TNF-α, IL-1β and IL-6 and decreased levels of serum immunoglobulins IgY and CD3⁺.4. In addition, with increasing age, IL-10 gene expression gradually increased in the BF and decreased in the spleen.5. In conclusion, VVD broilers have disorders of liver and kidney metabolism, inflammation and apoptosis of immune organs and increased levels of serum inflammatory factor proteins.

Comparison of As(III) Adsorption by Nanomagnetic Fe3O4, Activated Carbon and Modified Activated Carbon

As a kind of new material, nanomagnetic Fe3O4 (NMF) has many advantages in water and wastewater treatment. In this paper, the adsorption characteristic for arsenic(III) (As) by NMF was studied, and the adsorption was compared with the traditional adsorbent of activated carbon (AC) and modified activated carbon (MAC). The results showed that the NMF had high adsorption performance for As, and the adsorption performance of modified activated carbon and activated carbon were far lower than that of magnetic nanomagnetic Fe3O4. The adsorption capacity for As with NMF, MAC, and AC was 0.189 mg.g-1, 0.023 mg.g-1 and 0.013 mg.g-1 in 0.25 mg.L-1 As solution, respectively. The adsorption rate for As was different from the three adsorbents. For NMF, it needs only 10 minutes to reach an adsorption balance, while the time to balance was 20 minutes for MAC and more than 120 minutes for AC. The adsorption for As by the three adsorbents all conform to Langmuir adsorption isotherm, and the adsorption kinetics for As by the three adsorbents were in accordance with the pseudo-second-order kinetics model. The adsorption efficiency of MAC and AC was lower than nanomagnetic Fe3O4. The nanomagnetic Fe3O4 was an effective adsorbent for arsenic.

lncRNA Sequencing of Antler Mesenchymal Tissue Revealed that the Regulatory Network of Antler Cell Proliferation and Differentiation

Antlers have been widely studied due to their unique physiological characteristics, such as rapid growth, periodic shedding and regeneration. However, little is known about how antler growth is regulated by long non-coding RNA (lncRNA). The aim of the present study was to identify the lncRNAs expression profile and explore the function of lncRNAs during the antler growth. Herein, RNA-sequencing technology (RNA-seq) was performed on the three growth periods (early developmental period: EP, middle developmental period: MP, later developmental period: LP) of male sika deer (Cervus nippon) antler, 16 differentially expressed lncRNAs (DE lncRNAs) and 11 DE lncRNAs were identified in EP vs MP and MP vs LP related to cell proliferation and cell differentiation, respectively. Finally, lncRNAs-mRNAs co-expression networks were constructed based on the identified DE lncRNAs and their potential trans-target genes. The result reveals that lncRNAs may play diverse roles in different periods of antler growth. It provides a novel perspective for revealing the molecular mechanism of antler growth.

The Generation of a Lung Cancer Health Factor Distribution Using Patient Graphs Constructed From Electronic Medical Records: Retrospective Study

BACKGROUND

Electronic medical records (EMRs) of patients with lung cancer (LC) capture a variety of health factors. Understanding the distribution of these factors will help identify key factors for risk prediction in preventive screening for LC.

OBJECTIVE

We aimed to generate an integrated biomedical graph from EMR data and Unified Medical Language System (UMLS) ontology for LC, and to generate an LC health factor distribution from a hospital EMR of approximately 1 million patients.

METHODS

The data were collected from 2 sets of 1397 patients with and those without LC. A patient-centered health factor graph was plotted with 108,000 standardized data, and a graph database was generated to integrate the graphs of patient health factors and the UMLS ontology. With the patient graph, we calculated the connection delta ratio (CDR) for each of the health factors to measure the relative strength of the factor's relationship to LC.

RESULTS

The patient graph had 93,000 relations between the 2794 patient nodes and 650 factor nodes. An LC graph with 187 related biomedical concepts and 188 horizontal biomedical relations was plotted and linked to the patient graph. Searching the integrated biomedical graph with any number or category of health factors resulted in graphical representations of relationships between patients and factors, while searches using any patient presented the patient's health factors from the EMR and the LC knowledge graph (KG) from the UMLS in the same graph. Sorting the health factors by CDR in descending order generated a distribution of health factors for LC. The top 70 CDR-ranked factors of disease, symptom, medical history, observation, and laboratory test categories were verified to be concordant with those found in the literature.

CONCLUSIONS

By collecting standardized data of thousands of patients with and those without LC from the EMR, it was possible to generate a hospital-wide patient-centered health factor graph for graph search and presentation. The patient graph could be integrated with the UMLS KG for LC and thus enable hospitals to bring continuously updated international standard biomedical KGs from the UMLS for clinical use in hospitals. CDR analysis of the graph of patients with LC generated a CDR-sorted distribution of health factors, in which the top CDR-ranked health factors were concordant with the literature. The resulting distribution of LC health factors can be used to help personalize risk evaluation and preventive screening recommendations.

Prognosis and persistence of smell and taste dysfunction in patients with covid-19: meta-analysis with parametric cure modelling of recovery curves

OBJECTIVE

To clarify in patients with covid-19 the recovery rate of smell and taste, proportion with persistent dysfunction of smell and taste, and prognostic factors associated with recovery of smell and taste.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, Scopus, Cochrane Library, and medRxiv from inception to 3 October 2021.

REVIEW METHODS

Two blinded reviewers selected observational studies of adults (≥18 years) with covid-19 related dysfunction of smell or taste. Descriptive prognosis studies with time-to-event curves and prognostic association studies of any prognostic factor were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers extracted data, evaluated study bias using QUIPS, and appraised evidence quality using GRADE, following PRISMA and MOOSE reporting guidelines. Using iterative numerical algorithms, time-to-event individual patient data (IPD) were reconstructed and pooled to retrieve distribution-free summary survival curves, with recovery rates reported at 30 day intervals for participants who remained alive. To estimate the proportion with persistent smell and taste dysfunction, cure fractions from Weibull non-mixture cure models of plateaued survival curves were logit transformed and pooled in a two stage meta-analysis. Conventional aggregate data meta-analysis was performed to explore unadjusted associations of prognostic factors with recovery.

MAIN OUTCOME MEASURES

The primary outcomes were the proportions of patients remaining with smell or taste dysfunction. Secondary outcomes were the odds ratios of prognostic variables associated with recovery of smell and taste.

RESULTS

18 studies (3699 patients) from 4180 records were included in reconstructed IPD meta-analyses. Risk of bias was low to moderate; conclusions remained unaltered after exclusion of four high risk studies. Evidence quality was moderate to high. Based on parametric cure modelling, persistent self-reported smell and taste dysfunction could develop in an estimated 5.6% (95% confidence interval 2.7% to 11.0%, I2=70%, τ2=0.756, 95% prediction interval 0.7% to 33.5%) and 4.4% (1.2% to 14.6%, I2=67%, τ2=0.684, 95% prediction interval 0.0% to 49.0%) of patients, respectively. Sensitivity analyses suggest these could be underestimates. At 30, 60, 90, and 180 days, respectively, 74.1% (95% confidence interval 64.0% to 81.3%), 85.8% (77.6% to 90.9%), 90.0% (83.3% to 94.0%), and 95.7% (89.5% to 98.3%) of patients recovered their sense of smell (I2=0.0-77.2%, τ2=0.006-0.050) and 78.8% (70.5% to 84.7%), 87.7% (82.0% to 91.6%), 90.3% (83.5% to 94.3%), and 98.0% (92.2% to 95.5%) recovered their sense of taste (range of I2=0.0-72.1%, τ2=0.000-0.015). Women were less likely to recover their sense of smell (odds ratio 0.52, 95% confidence interval 0.37 to 0.72, seven studies, I2=20%, τ2=0.0224) and taste (0.31, 0.13 to 0.72, seven studies, I2=78%, τ2=0.5121) than men, and patients with greater initial severity of dysfunction (0.48, 0.31 to 0.73, five studies, I2=10%, τ2<0.001) or nasal congestion (0.42, 0.18 to 0.97, three studies, I2=0%, τ2<0.001) were less likely to recover their sense of smell.

CONCLUSIONS

A substantial proportion of patients with covid-19 might develop long lasting change in their sense of smell or taste. This could contribute to the growing burden of long covid.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021283922.

[Establishment of a culture system for human nasal mucosa organoids with controllable differentiation]

OBJECTIVE

To establish a culture system for human nasal mucosal organoids with controllable differentiation to reproduce the structure and function of the source tissue through staged expansion-differentiation culture.

METHODS

Fresh samples of surgically resected middle turbinate and nasal polyp tissues were collected, from which the nasal mucosa epithelial cells were isolated by enzymatic digestion and filtration for continuous culture at the air-liquid interface for expansion (EO group) or staged culture for expansion and differentiation (DO group). Immunohistochemical staining was used to characterize the structure, cellular composition and ciliary function of nasal mucosal organoids in the two groups. The secretion function of the differentiated nasal mucosal organoids in DO group was evaluated using PAS staining.

RESULTS

Both of the two organoid culture systems yielded vacuolar or solid spherical 3D organoids, and their diameters increased progressively with time. On day 16 of culture, more vacuolar organoids occurred in DO group, while more solid spherical organoids were seen in EO group, and the proportion of vacuoles was significantly greater in DO group than in EO group [(54.67±13.26)% vs (21.67±8.57)%, P < 0.05]. Short tandem repeat (STR) test of the nasal mucosal organoids and the source tissue showed a 100% match between them. On day 21 of culture, scanning and transmission electron microscopy of the nasal mucosal organoids identified ultrastructure of cilia in DO group and short villi structure in most of the organoids in EO group. Immunohistochemical staining showed positivity for P63 (basal cells), β-tubulin (ciliated columnar cells), and MUC5AC (goblet cells) in the organoids. Compared with those in EO group, the organoids in DO group showed significantly greater percentages of ciliated cells [(7.95±1.81)% vs (27.04±5.91)%, P < 0.05] and goblet cells [(14.46±0.93)% vs (39.85±5.43)%, P < 0.05) with a similar percentage of basal cells [(56.91±14.12)% vs (53.42±15.77)%, P > 0.05]. The differentiated nasal mucosal organoids in DO group were positively stained for glycogen.

CONCLUSION

The staged expansion-differentiation culture method allows more stable and prolonged growth of the cultured cells in vitro to produce organoids with controllable differentiation closely resembling the morphological structure and functions (ciliary function and secretory function) of the source tissue.

Joint synthesis and registration network for deformable MR-CBCT image registration for neurosurgical guidance

Objective.The accuracy of navigation in minimally invasive neurosurgery is often challenged by deep brain deformations (up to 10 mm due to egress of cerebrospinal fluid during neuroendoscopic approach). We propose a deep learning-based deformable registration method to address such deformations between preoperative MR and intraoperative CBCT.Approach.The registration method uses a joint image synthesis and registration network (denoted JSR) to simultaneously synthesize MR and CBCT images to the CT domain and perform CT domain registration using a multi-resolution pyramid. JSR was first trained using a simulated dataset (simulated CBCT and simulated deformations) and then refined on real clinical images via transfer learning. The performance of the multi-resolution JSR was compared to a single-resolution architecture as well as a series of alternative registration methods (symmetric normalization (SyN), VoxelMorph, and image synthesis-based registration methods).Main results.JSR achieved median Dice coefficient (DSC) of 0.69 in deep brain structures and median target registration error (TRE) of 1.94 mm in the simulation dataset, with improvement from single-resolution architecture (median DSC = 0.68 and median TRE = 2.14 mm). Additionally, JSR achieved superior registration compared to alternative methods-e.g. SyN (median DSC = 0.54, median TRE = 2.77 mm), VoxelMorph (median DSC = 0.52, median TRE = 2.66 mm) and provided registration runtime of less than 3 s. Similarly in the clinical dataset, JSR achieved median DSC = 0.72 and median TRE = 2.05 mm.Significance.The multi-resolution JSR network resolved deep brain deformations between MR and CBCT images with performance superior to other state-of-the-art methods. The accuracy and runtime support translation of the method to further clinical studies in high-precision neurosurgery.

Long-term immune responses in patients with confirmed novel coronavirus disease-2019: a 9-month prospective cohort study in Shanghai, China

BACKGROUND

The duration of antibodies against SARS-CoV-2 in Covid-19 patients remains uncertain. Longitudinal serological studies are needed to prevent disease and transmission of the virus.

METHODS

In 2020, 414 blood samples were tested, obtained from 157 confirmed Covid-19 patients, in a prospective cohort study in Shanghai.

RESULTS

The seropositive rate of IgM peaked at 40.5% (17/42) within 1 month after illness onset and then declined. The seropositive rate of IgG was 90.6% (58/64) after 2 months, remained above 85% from 2 to 9 months and was 90.9% (40/44) after 9 months. Generalized estimating equations models suggested that IgM (P < 0.001) but not IgG significantly decreased over time. Age ≥ 40 years (adjusted odds ratio [aOR] 4.531; 95% confidence interval [CI] 1.879-10.932), and cigarette smoking (aOR 0.344; 95% CI 0.124-0.951) were associated with IgG, and age ≥ 40 years (aOR 2.820; 95% CI 1.579-5.036) was associated with IgM. After seroconversion, over 90% and 75.1% of subjects were estimated to remain IgG-positive 220 and 254 days, respectively. Of 1420 self-reported symptoms questionnaires, only 5% reported symptoms 9 months after onset.

CONCLUSIONS

In patients with a history of natural infection, anti-SARS-CoV-2 IgG is long-lived, being present for at least 9 months after illness onset. The long duration of natural immunity can mitigate and eliminate Covid-19 and the ongoing pandemic.

Deformable MR-CT image registration using an unsupervised, dual-channel network for neurosurgical guidance

PURPOSE

The accuracy of minimally invasive, intracranial neurosurgery can be challenged by deformation of brain tissue - e.g., up to 10 mm due to egress of cerebrospinal fluid during neuroendoscopic approach. We report an unsupervised, deep learning-based registration framework to resolve such deformations between preoperative MR and intraoperative CT with fast runtime for neurosurgical guidance.

METHOD

The framework incorporates subnetworks for MR and CT image synthesis with a dual-channel registration subnetwork (with synthesis uncertainty providing spatially varying weights on the dual-channel loss) to estimate a diffeomorphic deformation field from both the MR and CT channels. An end-to-end training is proposed that jointly optimizes both the synthesis and registration subnetworks. The proposed framework was investigated using three datasets: (1) paired MR/CT with simulated deformations; (2) paired MR/CT with real deformations; and (3) a neurosurgery dataset with real deformation. Two state-of-the-art methods (Symmetric Normalization and VoxelMorph) were implemented as a basis of comparison, and variations in the proposed dual-channel network were investigated, including single-channel registration, fusion without uncertainty weighting, and conventional sequential training of the synthesis and registration subnetworks.

RESULTS

The proposed method achieved: (1) Dice coefficient = 0.82±0.07 and TRE = 1.2 ± 0.6 mm on paired MR/CT with simulated deformations; (2) Dice coefficient = 0.83 ± 0.07 and TRE = 1.4 ± 0.7 mm on paired MR/CT with real deformations; and (3) Dice = 0.79 ± 0.13 and TRE = 1.6 ± 1.0 mm on the neurosurgery dataset with real deformations. The dual-channel registration with uncertainty weighting demonstrated superior performance (e.g., TRE = 1.2 ± 0.6 mm) compared to single-channel registration (TRE = 1.6 ± 1.0 mm, p < 0.05 for CT channel and TRE = 1.3 ± 0.7 mm for MR channel) and dual-channel registration without uncertainty weighting (TRE = 1.4 ± 0.8 mm, p < 0.05). End-to-end training of the synthesis and registration subnetworks also improved performance compared to the conventional sequential training strategy (TRE = 1.3 ± 0.6 mm). Registration runtime with the proposed network was ∼3 s.

CONCLUSION

The deformable registration framework based on dual-channel MR/CT registration with spatially varying weights and end-to-end training achieved geometric accuracy and runtime that was superior to state-of-the-art baseline methods and various ablations of the proposed network. The accuracy and runtime of the method may be compatible with the requirements of high-precision neurosurgery.

Prevalence, types and treatment of bradycardia in obstructive sleep apnea - A systematic review and meta-analysis

BACKGROUND

The association of obstructive sleep apnea (OSA) with bradycardia is not well-characterized, which may confer significant morbidity and mortality if left untreated. We sought to clarify the prevalence of comorbid OSA and bradycardia, and the effect of continuous positive airway pressure (CPAP) therapy on bradycardia outcomes.

METHODS

We systematically searched four electronic databases (PubMed, Embase, Cochrane Library, Scopus) for randomized or observational studies reporting the co-prevalence of sleep apnea and bradycardia or evaluated the use of CPAP on the incidence of bradycardias. We used random-effects models in all meta-analyses and evaluated heterogeneity using I².

RESULTS

We included 34 articles from 7204 records, comprising 4852 patients. Among patients with OSA, the pooled prevalence of daytime and nocturnal bradycardia were 25% (95% CI: 18.6 to 32.7) and 69.8% (95% CI: 41.7 to 88.2) respectively. Among patients with bradycardia, the pooled prevalence of OSA was 56.8% (95% CI: 21.5 to 86.3). CPAP treatment, compared to those without, did not significantly reduce the risk of daytime (two randomized trials; RR: 0.50; 95% CI: 0.11 to 2.21) or nocturnal bradycardia (one randomized-controlled trial and one cohort study; RR: 0.76; 95% CI: 0.48 to 1.20).

CONCLUSIONS

This meta-analysis demonstrates a high comorbid disease burden between OSA and bradycardia. Future research should explore the treatment effect of CPAP on bradycardia incidence, as compared to placebo.

Deformable 3D-2D registration for high-precision guidance and verification of neuroelectrode placement

Purpose.Accurate neuroelectrode placement is essential to effective monitoring or stimulation of neurosurgery targets. This work presents and evaluates a method that combines deep learning and model-based deformable 3D-2D registration to guide and verify neuroelectrode placement using intraoperative imaging.Methods.The registration method consists of three stages: (1) detection of neuroelectrodes in a pair of fluoroscopy images using a deep learning approach; (2) determination of correspondence and initial 3D localization among neuroelectrode detections in the two projection images; and (3) deformable 3D-2D registration of neuroelectrodes according to a physical device model. The method was evaluated in phantom, cadaver, and clinical studies in terms of (a) the accuracy of neuroelectrode registration and (b) the quality of metal artifact reduction (MAR) in cone-beam CT (CBCT) in which the deformably registered neuroelectrode models are taken as input to the MAR.Results.The combined deep learning and model-based deformable 3D-2D registration approach achieved 0.2 ± 0.1 mm accuracy in cadaver studies and 0.6 ± 0.3 mm accuracy in clinical studies. The detection network and 3D correspondence provided initialization of 3D-2D registration within 2 mm, which facilitated end-to-end registration runtime within 10 s. Metal artifacts, quantified as the standard deviation in voxel values in tissue adjacent to neuroelectrodes, were reduced by 72% in phantom studies and by 60% in first clinical studies.Conclusions.The method combines the speed and generalizability of deep learning (for initialization) with the precision and reliability of physical model-based registration to achieve accurate deformable 3D-2D registration and MAR in functional neurosurgery. Accurate 3D-2D guidance from fluoroscopy could overcome limitations associated with deformation in conventional navigation, and improved MAR could improve CBCT verification of neuroelectrode placement.

Chromosome-scale assembly and whole-genome sequencing of 266 giant panda roundworms provide insights into their evolution, adaptation and potential drug targets

Helminth diseases have long been a threat to the health of humans and animals. Roundworms are important organisms for studying parasitic mechanisms, disease transmission and prevention. The study of parasites in the giant panda is of importance for understanding how roundworms adapt to the host. Here, we report a high‐quality chromosome‐scale genome of Baylisascaris schroederi with a genome size of 253.60 Mb and 19,262 predicted protein‐coding genes. We found that gene families related to epidermal chitin synthesis and environmental information processes in the roundworm genome have expanded significantly. Furthermore, we demonstrated unique genes involved in essential amino acid metabolism in the B. schroederi genome, inferred to be essential for the adaptation to the giant panda‐specific diet. In addition, under different deworming pressures, we found that four resistance‐related genes (glc‐1, nrf‐6, bre‐4 and ced‐7) were under strong positive selection in a captive population. Finally, 23 known drug targets and 47 potential drug target proteins were identified. The genome provides a unique reference for inferring the early evolution of roundworms and their adaptation to the host. Population genetic analysis and drug sensitivity prediction provide insights revealing the impact of deworming history on population genetic structure of importance for disease prevention.

[Prevalence and influencing factors of deciduous dental caries among preschool children in Qingdao city in 2019]

In 2019, the rate of primary tooth caries rate among 1 598 preschool children in Shinan District and Shibei District of Qingdao was 59.4%. The multivariate logistic regression model showed that compared with children ≤ 2 years old with history of iron deficiency anemia (IDA), suffering IDA, breastfeeding to 2 years old and no tooth melanin, children ≤ 2 years old without history of IDA, not suffering IDA, breastfeeding to less than 2 years old and heavy tooth melanin had a lower risk of primary tooth caries, with OR (95%CI) values about 0.328 (0.197-0.549), 0.354 (0.208-0.603), 0.636 (0.437-0.926) and 0.301 (0.143-0.635), respectively.

Fast Estimation of Møller-Plesset Correlation Energies Based on Atomic Contributions

Dynamic correlation plays an important role in the accurate calculation of chemical compounds such as the description of equilibrium structures in chemical systems. A model for the fast estimation of dynamic correlation energy is introduced in this work. This model is based on the idea of decomposition of the contribution of dynamic correlation energy calculated by nth order Møller-Plesset perturbation (MPn) theory with respect to atomic regions. Multiple levels of theory, including MP2, MP2.5, and MP4, are used as the reference, and the corresponding correlation energy densities are calculated. The proposed model is concise, fast, and promising for practical use, such as the prediction of reaction energies. It can also work as a baseline model or pretrained model for follow-up studies of machine learning.

Excitation functions of proton induced reactions on titanium and copper

Excitation functions of the Tnati(p,x)S43,47c, V48 and Cnatu(p,x)⁶⁴Cu, Z62,65n reactions were measured in the energy range of 8.8-18.4 MeV by using the stacked-foil activation technique and off-line gamma spectroscopy. The irradiation was carried out at the superconducting linac of the Institute of Modern Physics, Chinese Academy of Sciences. Besides, the reliability and effectiveness of theoretical data from the TALYS code, recommended data of the International Atomic Energy Agency (IAEA) and evaluated nuclear data of the ENDF/B-VIII.0, JENDL-4.0/HE and PADF-2007 libraries were evaluated and verified by comparing with experimental data. Our experimental results agree with most of the available literature data. TALYS-1.95 code could not reproduce, in most cases, the experimental data. Evaluated nuclear data from the ENDF/B-VIII.0, JENDL-4.0/HE and PADF-2007 libraries are able to reproduce, in most cases, the experimental data trend. Recommended data of the IAEA are in good consistent with our work and most of the available literature data.

[Application of superficial inferior epigastric artery flaps to repair oral and maxillofacial defects with the aid of digital three-dimensional reconstruction technique]

Objective: To explore the application value of digital three-dimensional(3D) reconstruction technology in the repair of oral and maxillofacial defects with superficial inferior epigastric artery (SIEA) flap. Methods: Twelve cases of oral cancer patients, including 8 males and 4 females; aged (57.4±12.6) years, were selected from the Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Bengbu Medical College from January 2018 to October 2019 and were proposed to repair with SIEA flap. There were 10 cases of squamous cell carcinoma, one case of adenoid cystic carcinoma and 1 case of mucinous epidermal carcinoma. The data were imported into AW4.7 software for post-processing. The left or right dominant donor area was selected to clarify the origin, diameter, alignment, and location of penetration point of the flap blood supply, and digital 3D reconstruction technology was used to guide the flap preoperative design. Results: Eleven cases were repaired by SIEA flap in 12 patients, one case was repaired by superficial iliac artery flap because the source artery was undiscovered, one case had venous vascular crisis after surgery, and the rest of the flap survived. In 11 patients repaired with SIEA flap, there was no significant difference between the preoperative SIEA diameter measured by CTA [(1.0±0.3) mm] and the actual measured value [(1.1±0.3) mm] (P>0.05). The follow-up was 6 to 12 months, with an average of 10 months, and the donor-receiver areas were all healed in phase Ⅰ. No obvious complications occurred, and the abdominal scar was hidden. Conclusions: In the SIEA flap repair oral and maxillofacial defect reconstruction surgery, the use of digital 3D reconstruction technology can objectively reflect the diameter and the location of the superficial artery of the abdominal wall before surgery, effectively reduce the difficulty and risk of flap surgery.

Data-Driven Deformable 3D-2D Registration for Guiding Neuroelectrode Placement in Deep Brain Stimulation

PURPOSE

Deep brain stimulation is a neurosurgical procedure used in treatment of a growing spectrum of movement disorders. Inaccuracies in electrode placement, however, can result in poor symptom control or adverse effects and confound variability in clinical outcomes. A deformable 3D-2D registration method is presented for high-precision 3D guidance of neuroelectrodes.

METHODS

The approach employs a model-based, deformable algorithm for 3D-2D image registration. Variations in lead design are captured in a parametric 3D model based on a B-spline curve. The registration is solved through iterative optimization of 16 degrees-of-freedom that maximize image similarity between the 2 acquired radiographs and simulated forward projections of the neuroelectrode model. The approach was evaluated in phantom models with respect to pertinent imaging parameters, including view selection and imaging dose.

RESULTS

The results demonstrate an accuracy of (0.2 ± 0.2) mm in 3D localization of individual electrodes. The solution was observed to be robust to changes in pertinent imaging parameters, which demonstrate accurate localization with ≥20° view separation and at 1/10^th the dose of a standard fluoroscopy frame.

CONCLUSIONS

The presented approach provides the means for guiding neuroelectrode placement from 2 low-dose radiographic images in a manner that accommodates potential deformations at the target anatomical site. Future work will focus on improving runtime though learning-based initialization, application in reducing reconstruction metal artifacts for 3D verification of placement, and extensive evaluation in clinical data from an IRB study underway.

Fluoroscopic Guidance of a Surgical Robot: Pre-clinical Evaluation in Pelvic Guidewire Placement

PURPOSE

A method and prototype for a fluoroscopically-guided surgical robot is reported for assisting pelvic fracture fixation. The approach extends the compatibility of existing guidance methods with C-arms that are in mainstream use (without prior geometric calibration) using an online calibration of the C-arm geometry automated via registration to patient anatomy. We report the first preclinical studies of this method in cadaver for evaluation of geometric accuracy.

METHODS

The robot is placed over the patient within the imaging field-of-view and radiographs are acquired as the robot rotates an attached instrument. The radiographs are then used to perform an online geometric calibration via 3D-2D image registration, which solves for the intrinsic and extrinsic parameters of the C-arm imaging system with respect to the patient. The solved projective geometry is then be used to register the robot to the patient and drive the robot to planned trajectories. This method is applied to a robotic system consisting of a drill guide instrument for guidewire placement and evaluated in experiments using a cadaver specimen.

RESULTS

Robotic drill guide alignment to trajectories defined in the cadaver pelvis were accurate within 2 mm and 1° (on average) using the calibration-free approach. Conformance of trajectories within bone corridors was confirmed in cadaver by extrapolating the aligned drill guide trajectory into the cadaver pelvis.

CONCLUSION

This study demonstrates the accuracy of image-guided robotic positioning without prior calibration of the C-arm gantry, facilitating the use of surgical robots with simpler imaging devices that cannot establish or maintain an offline calibration. Future work includes testing of the system in a clinical setting with trained orthopaedic surgeons and residents.

Filament extrusion of bioresorbable PDLGA for additive manufacturing utilising diatom biosilica to inhibit process-induced thermal degradation

Bone scaffolds are often fabricated by initially producing custom-made filaments by twin-screw extruder and subsequently fabricating into 3D scaffolds using fused deposition modelling. This study aims to directly compare the effect of two alternative silica-rich filler materials on the thermo-mechanical properties of such scaffolds after extrusion and printing. Poly (DL-lactide-co-glycolide) (PDLGA) was blended with either 45S5 Bioglass (5 wt %) or Biosilica (1 and 5 wt%) isolated from Cyclotella meneghiniana a freshwater diatom were tested. Diatom-PDLGA was found to have similar mechanical strength and ductility to pure-PDLGA, whereas Bioglass-PDLGA was found induce a more brittle behaviour. Bioglass-PDLGA was also found to have the lowest toughness in terms of energy absorption to failure. The TGA results suggested that significant thermal degradation in both the Bioglass filaments and scaffolds had occurred as a result of processing. However, diatom biosilica was found to inhibit thermal degradation of the PDLGA. Furthermore, evidence suggested the agglomeration of Bioglass particles occurred during processing the Bioglass-PDLGA filaments. Overall, diatom biosilica was found to be a promising candidate as a bone filler additive in 3D printed PDLGA scaffolds, whereas Bioglass caused some potentially detrimental effects on performance.

Incretin mimetics and sodium-glucose co-transporter 2 inhibitors as monotherapy or add-on to metformin for treatment of type 2 diabetes: a systematic review and network meta-analysis

PURPOSE

Although there are many different methods of treating type 2 diabetes (T2D), it is still difficult to draw coincident conclusions concerning the efficacy and safety of different classes of new drugs, and the recommendation level of them has still kept uncertain as second anti-diabetic agents. Therefore, the aim of this study was to summarize evidence on the efficacy and safety of DPP-4is, GLP-1RAs and SGLT-2is as monotherapy or add-on to metformin (Met) for treatment of T2D.

MATERIALS AND METHODS

We searched PubMed, Embase, Cochrane library and ClinicalTrials.gov for relevant articles in keeping with established methods using terms associated with anti-diabetic agents up to February, 2020, with no start date restriction. Weighted mean difference and risk ratios with 95% confidence intervals were calculated within traditional and network meta-analysis. Primary outcomes were the mean change in hemoglobin A1c (HbA1c), fasting plasma glucose (FPG) change and the frequency of hypoglycemic events from baseline after 12 weeks of treatment.

RESULTS

In total, 64 eligible studies comprising 37,780 patients and 7 treatment strategies were included. The results of primary outcomes showed that GLP-1RAs were significantly more effective than DPP-4is or SGLT-2is in reducing HbA1c when add-on to Met. For FPG, both GLP-1RAs and SGLT-2is significantly reduced FPG compared with DPP-4is whether add-on to Met or not. For hypoglycemia, monotherapy has a lower risk than combination therapy except for SGLT-2is. Ranking probability analysis indicated that GLP-1RAs and SGLT-2is, respectively, reduced HbA1c and FPG most when add-on to Met. Meanwhile, GLP-1RAs took the lowest risk to induce the hypoglycemia, whereas GLP-1RAs plus Met the highest.

CONCLUSIONS

Both GLP-1RAs and SGLT-2is have their own advantages in efficacy and safety. Monotherapy is beneficial for reducing the risk of hypoglycemia. The recommendation should be a patient-centered approach when selecting treatment choices.

Fracture reduction planning and guidance in orthopaedic trauma surgery via multi-body image registration

PURPOSES

Surgical reduction of pelvic fracture is a challenging procedure, and accurate restoration of natural morphology is essential to obtaining positive functional outcome. The procedure often requires extensive preoperative planning, long fluoroscopic exposure time, and trial-and-error to achieve accurate reduction. We report a multi-body registration framework for reduction planning using preoperative CT and intraoperative guidance using routine 2D fluoroscopy that could help address such challenges.

METHOD

The framework starts with semi-automatic segmentation of fractured bone fragments in preoperative CT using continuous max-flow. For reduction planning, a multi-to-one registration is performed to register bone fragments to an adaptive template that adjusts to patient-specific bone shapes and poses. The framework further registers bone fragments to intraoperative fluoroscopy to provide 2D fluoroscopy guidance and/or 3D navigation relative to the reduction plan. The framework was investigated in three studies: (1) a simulation study of 40 CT images simulating three fracture categories (unilateral two-body, unilateral three-body, and bilateral two-body); (2) a proof-of-concept cadaver study to mimic clinical scenario; and (3) a retrospective clinical study investigating feasibility in three cases of increasing severity and accuracy requirement.

RESULTS

Segmentation of simulated pelvic fracture demonstrated Dice coefficient of 0.92±0.06. Reduction planning using the adaptive template achieved 2-3 mm and 2-3° error for the three fracture categories, significantly better than planning based on mirroring of contralateral anatomy. 3D-2D registration yielded ~2 mm and 0.5° accuracy, providing accurate guidance with respect to the preoperative reduction plan. The cadaver study and retrospective clinical study demonstrated comparable accuracy: ~0.90 Dice coefficient in segmentation, ~3 mm accuracy in reduction planning, and ~2 mm accuracy in 3D-2D registration.

CONCLUSION

The registration framework demonstrated planning and guidance accuracy within clinical requirements in both simulation and clinical feasibility studies for a broad range of fracture-dislocation patterns. Using routinely acquired preoperative CT and intraoperative fluoroscopy, the framework could improve the accuracy of pelvic fracture reduction, reduce radiation dose, and could integrate well with common clinical workflow without the need for additional navigation systems.

Microtubule organization defects in Arabidopsis thaliana

Microtubules (MT) are critical cytoskeletal filaments that have several functions in cell morphogenesis, cell division, vesicle transport and cytoplasmic separation in the spatiotemporal regulation of eukaryotic cells. Formation of MT requires the co-interaction of MT nucleation and α-β-tubulins, as well as MT-associated proteins (MAP). Many key MAP contributing to MT nucleation and elongation are essential for MT nucleation and regulation of MT dynamics, and are conserved in the plant kingdom. Therefore, the deletion or decrease of γ-tubulin ring complex (γTuRC) components and related MAP, such as the augmin complex, NEDD1, MZT1, EB1, MAP65, etc., in Arabidopsis thaliana results in MT organizational defects in the spindle and phragmoplast MT, as well as in chromosome defects. In addition, similar defects in MT organization and chromosome structure have been observed in plants under abiotic stress conditions, such as under high UV-B radiation. The MT can sense the signal from UV-B radiation, resulting in abnormal MT arrangement. Further studies are required to determine whether the abnormal chromosomes induced by UV-B radiation can be attributed to the involvement of abnormal MT arrays in chromosome migration after DNA damage.

Epidemiological and clinical characteristics of 161 discharged cases with coronavirus disease 2019 in Shanghai, China

Background

In December 2019, the outbreak of coronavirus disease 2019 (COVID-19) began in Wuhan, China, and rapidly spread to other regions. We aimed to further describe the epidemiological and clinical characteristics of discharged COVID-19 cases and evaluate the public health interventions.

Methods

We collected epidemiological and clinical data of all discharged COVID-19 cases as of 17 February 2020 in Shanghai. The key epidemiological distributions were estimated and outcomes were also compared between patients whose illness were before 24 January and those whose illness were after 24 January.

Results

Of 161 discharged COVID-19 cases, the median age was 45 years, and 80 (49.7%) cases were male. All of the cases were categorized as clinical moderate type. The most common initial symptoms were fever (85.7%), cough (41.0%), fatigue (19.3%), muscle ache (17.4%), sputum production (14.9%), and there were six asymptomatic cases. 39 (24.2%) cases got infected in Shanghai, and three of them were second-generation cases of Shanghai native cases. The estimated median of the time from onset to first medical visit, admission, disease confirmation, and discharge for 161 cases was 1.0 day (95% CI, 0.6–1.2), 2.0 days (95% CI, 1.5–2.6), 5.2 days (95% CI, 4.6–5.7), 18.1 days (95% CI, 17.4–18.8), respectively. The estimated median of the time from admission to discharge was 14.0 days (95% CI, 13.3–14.6). The time from onset to first medical visit, admission and disease confirmation were all shortened after the Shanghai’s first-level public health emergency response. In Cox regression model, the significant independent covariates for the duration of hospitalization were age, the time from onset to admission and the first-level public health emergency response.

Conclusions

Local transmission had occurred in Shanghai in late January 2020. The estimated median of the time from onset to discharge of moderate COVID-19 was 18.1 days in Shanghai. Time intervals from onset to first medical visit, admission and disease confirmation were all shortened after the Shanghai’s first-level public health emergency response. Age, the first-level public health emergency response and the time from onset to admission were the impact factors for the duration of hospitalization.

Assessment of genetic diversity of Cervus albirostris (white-lipped deer) by microsatellite markers

Cervus albirostris (white-lipped deer) is a unique plateau deer in China. In order to conserve the white-lipped deer population and maintain its sustainable development in Liaoyang, China, ten microsatellite markers was used to analyze the genetic diversity of 42 white-lipped deer, an ex-situ conservation population from Yushu (Qinghai) to Liaoyang (Liaoning). The results showed that expected heterozygosity ranged from 0.399 to 0.825 with a mean of 0.6071, while observed heterozygosity varied from 0.081 to 0.692 with a mean of 0.4456. This study contributes to the study of the unique genetic resources in this ex-situ conservation population and provides a perspective for better implementation of ex-situ conservation of white-lipped deer population in Liaoyang, China.

Actin filaments altered distribution in wheat (Triticum aestivum) "Bending Root" to respond to enhanced Ultraviolet-B radiation

Plants adjust their shoot growth to acclimate to changing environmental factors, such as to enhanced Ultraviolet-B (UV-B) radiation. However, people have ignored that plant roots can also respond to UV-B light. Here, we find the morphology curled wheat roots under UV-B radiation, that we call, "bending roots." The curly region is the transition zone of the root after observed at the cellular level. After exposed to enhanced UV-B radiation for 2 d (10.08 KJ/m2/d), cell size decreased and actin filaments gathered in wheat roots. We also find that H2O2 production increased and that content of the indole-3-acetic acid (IAA) increased remarkably. The pharmacological experiment revealed that actin filaments gathered and polymerized into bundles in the wheat root cells after irrigated H2O2 and IAA. These results indicated that actin filaments changed their distribution and formed the "bending root," which was related to H2O2 production and increase in IAA. Overall, actin filaments in wheat root cells could be a subcellular target of UV-B radiation, and its disruption determines root morphology.

C-arm orbits for metal artifact avoidance (MAA) in cone-beam CT

Metal artifacts present a challenge to cone-beam CT (CBCT) image-guided surgery, obscuring visualization of metal instruments and adjacent anatomy-often in the very region of interest pertinent to the imaging/surgical tasks. We present a method to reduce the influence of metal artifacts by prospectively defining an image acquisition protocol-viz., the C-arm source-detector orbit-that mitigates metal-induced biases in the projection data. The metal artifact avoidance (MAA) method is compatible with simple mobile C-arms, does not require exact prior information on the patient or metal implants, and is consistent with 3D filtered backprojection (FBP), more advanced (e.g. polyenergetic) model-based image reconstruction (MBIR), and metal artifact reduction (MAR) post-processing methods. The MAA method consists of: (i) coarse localization of metal objects in the field-of-view (FOV) via two or more low-dose scout projection views and segmentation (e.g. a simple U-Net) in coarse backprojection; (ii) model-based prediction of metal-induced x-ray spectral shift for all source-detector vertices accessible by the imaging system (e.g. gantry rotation and tilt angles); and (iii) identification of a circular or non-circular orbit that reduces the variation in spectral shift. The method was developed, tested, and evaluated in a series of studies presenting increasing levels of complexity and realism, including digital simulations, phantom experiment, and cadaver experiment in the context of image-guided spine surgery (pedicle screw implants). The MAA method accurately predicted tilted circular and non-circular orbits that reduced the magnitude of metal artifacts in CBCT reconstructions. Realistic distributions of metal instrumentation were successfully localized (0.71 median Dice coefficient) from 2-6 low-dose scout views even in complex anatomical scenes. The MAA-predicted tilted circular orbits reduced root-mean-square error (RMSE) in 3D image reconstructions by 46%-70% and 'blooming' artifacts (apparent width of the screw shaft) by 20-45%. Non-circular orbits defined by MAA achieved a further ∼46% reduction in RMSE compared to the best (tilted) circular orbit. The MAA method presents a practical means to predict C-arm orbits that minimize spectral bias from metal instrumentation. Resulting orbits-either simple tilted circular orbits or more complex non-circular orbits that can be executed with a motorized multi-axis C-arm-exhibited substantial reduction of metal artifacts in raw CBCT reconstructions by virtue of higher fidelity projection data, which are in turn compatible with subsequent MAR post-processing and/or polyenergetic MBIR to further reduce artifacts.