[Cohort study on the association between hyperopia reserve and myopia incidence in primary school students: the Anyang Childhood Eye Study]

Objective: To analyze the longitudinal association between hyperopia reserve and the cumulative incidence of myopia in grade 1 primary school students. Methods: Cohort study. This study included 2 628 grade 1 primary school students (2 628 eyes) who without myopic at baseline from the Anyang Childhood Eye Study. There were 1 515 male and 1 113 female, aged(7.16±0.40) years. Every year, cycloplegic autorefraction was performed with 1% cyclopentolate eye drops to obtain data of hyperopia reserve. Students with different ranges of hyperopia reserve at baseline were analyzed. Axial length, anterior chamber depth, corneal curvature, lens thickness, and other parameters were obtained by ocular biometrics and compared by the independent sample ttest. Qualitative data were described by frequency and percentage, and comparison between groups was performed by the Chi-square test or exact probability method. Linear regression was used to analyze the association between baseline hyperopia reserve and spherical equivalent at 5 years. Results: The average hyperopia reserve was (+1.09±0.78) diopters (D) in grade 1 non-myopic children. Axial length, anterior chamber depth, corneal radius of curvature, and lens thickness were (22.66±0.72), (2.88±0.24), (7.80±0.25) and (3.62±0.19) mm, respectively. The cumulative incidence of myopia among non-myopic grade 1 primary school students was 8.5%, 21.5%, 35.6%, 47.6% and 64.1% at 1, 2, 3, 4 and 5 years, respectively. The incidence of myopia in girls was significantly higher than that in boys at 3, 4 and 5 years. The 5-year cumulative incidence of myopia was 4.6%, 26.3%, 52.3%, 78.6%, 92.6% and 94.3%, respectively, corresponding to students with baseline hyperopia reserve of >+2.00 D,+1.50 D to +2.00 D,+1.00 D to +1.50 D,+0.50 D to +1.00 D, 0.00 D to +0.50 D and -0.50 D to 0.00 D, and the difference was statistically significant (χ²=490.59, P<0.001). The regression equation between baseline hyperopia reserve and 5-year spherical equivalent was as follows: 5-year spherical equivalent =-3.135+1.692·baseline hyperopia reserve (R²=0.454, P<0.001). Conclusions: The lower the hyperopia reserve, the higher the incidence of myopia. Monitoring children's hyperopia reserve and early protection to reduce its consumption and timely detection of children at high risk of myopia are of great significance to prevent the occurrence and development of myopia.

[Spindle cell hemangioma: a clinicopathological and molecular analysis of eight cases]

Objective: To investigate the clinicopathological and genetic characteristics of spindle cell hemangioma (SCH). Methods: The clinical, morphological and immunohistochemical features of 8 SCHs diagnosed from January 2013 to September 2021 in West China Hospital, Sichuan University, Chengdu, China were retrospectively analyzed. Hotspot mutations for IDH1 codon 132 and IDH2 codon 172 were tested in 4 SCHs and 29 other non-SCH lesions using Sanger sequencing. Results: The 8 cases occurred in patients with a wide age range, from neonate to 46 years (mean 28 years, median 32 years). Both genders were equally affected. The course of the disease spanned from half a year to 31 years. Two SCHs were recurrent tumors. All tumors involved the distal extremities (4 of foot, 2 of ankle and 2 of hand). Six cases were presented as a single lesion and 2 cases as multiple lesions. The tumor diameters were 1-5 cm. All the 8 SCHs were typically composed of cavernous vascular space and solid components consisting of slit-like vessels, spindle cells and epithelioid endothelial cells which often exhibited cytoplasmic vacuolation. These two alternating components and the vacuolated epithelioid endothelial cells were the distinctive diagnostic clues for SCH. Vascular endothelial cells including epithelioid cells in the solid areas expressed CD31 (8/8), ERG (4/4), CD34 (5/8) and D2-40 (2/3). The spindle cells expressed SMA (8/8). Neither endothelial cells nor spindle cells expressed HHV8 (0/7), Desmin (0/5) or S-100 (0/3). Mutations were revealed in 2 SCHs, with IDH1 mutation (p.R132C) and IDH2 mutation (p.R172G), respectively. The IDH1/2 gene hotspot mutations were not found in the remaining 2 SCHs or the other 29 non-SCH lesions. Simple excisions were performed for 7 cases, and partial resection for 1 case. Follow-up information was obtained in 6 cases, with follow-up time ranging from 5 to 90 months (average, 46 months). No metastasis occurred in the 6 cases. No recurrence occurred in cases treated with simple excision. The residual lesions of the patient who received partial resection were stable. Conclusions: SCH is rare and should be differentiated from a variety of benign and malignant vascular lesions. An accurate diagnosis of SCH is clinically important and can be achieved by combining clinical information and typical pathological presentation. IDH1/2 gene hotspot mutations are specific to SCH in vascular lesions. Genetic detection is helpful in the diagnosis of challenging cases.

[Diagnostic value of MDM2 RNA in situ hybridization in atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma]

Objective: To investigate the value of MDM2 RNA in situ hybridization (RNA-ISH) in diagnosing atypical lipomatous tumor/well-differentiated liposarcoma (ALT/WDL) and dedifferentiated liposarcoma (DDL). Methods: A total of 26 ALT/WDL/DDLs diagnosed from March 2017 to May 2019 in West China Hospital, Sichuan University, Chengdu, China and 18 control cases were included. MDM2 RNA-ISH was performed on all samples and compared with the fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) regarding their performance in detecting MDM2. Results: All samples were detected successfully using the three methods. Among 26 ALT/WDL/DDLs, all cases showed MDM2 amplification and positivity for MDM2 RNA-ISH (26/26, 100%). Twenty-four (24/26, 92.3%) of the 26 tested cases were positive for MDM2 IHC while two of them were negative. Eighteen control cases were all negative for MDM2 FISH and RNA-ISH, and 15 (15/18) cases were negative for MDM2 IHC. The sensitivity and specificity of RNA-ISH were both 100%, and those of MDM2 IHC were 92.3% and 83.3%, respectively. Diffuse staining was identified in all MDM2 RNA-ISH positive ALT/WDL/DDLs, but identified in only 8/24 (33.3%) of the MDM2 IHC positive cases. Among the 11 ALT/WDL/DDL samples evaluated on tissue microarray, the positive rate of MDM2 RNA-ISH was 100% with diffuse staining in all cases. The positive rate of MDM2 IHC was 9/11 while only 1 of the 9 cases showed diffuse staining. The result of MDM2 RNA-ISH was identical to that of MDM2 FISH and was overall consistent with that of MDM2 IHC (Kappa=0.763, P<0.001). Conclusions: In ALT/WDL/DDLs, results of MDM2 RNA-ISH are highly consistent with those of FISH. MDM2 RNA-ISH is more sensitive and more specific and has more diffuse positive signals than the IHC. The findings indicate that MDM2 RNA-ISH is highly valuable for the diagnosis and differential diagnosis of ALT/WDL/DDLs.

Use of real-time artificial intelligence in detection of abnormal image patterns in standard sonographic reference planes in screening for fetal intracranial malformations

OBJECTIVES

To develop and validate an artificial intelligence system, the Prenatal ultrasound diagnosis Artificial Intelligence Conduct System (PAICS), to detect different patterns of fetal intracranial abnormality in standard sonographic reference planes for screening for congenital central nervous system (CNS) malformations.

METHODS

Neurosonographic images from normal fetuses and fetuses with CNS malformations at 18-40 gestational weeks were retrieved from the databases of two tertiary hospitals in China and assigned randomly (ratio, 8:1:1) to training, fine-tuning and internal validation datasets to develop and evaluate the PAICS. The system was built based on a real-time convolutional neural network (CNN) algorithm, You Only Look Once, version 3 (YOLOv3). An image dataset from a third tertiary hospital was used to further validate, externally, the performance of the PAICS and to compare its performance with that of sonologists with different levels of expertise. Furthermore, a prospective video dataset was employed to evaluate the performance of the PAICS in a real-time scan scenario. The diagnostic accuracy, sensitivity, specificity and area under the receiver-operating-characteristics curve (AUC) were calculated to assess the performance of the PAICS and to compare this with the performance of sonologists with different levels of experience.

RESULTS

In total, 43 890 images from 16 297 pregnancies and 169 videos from 166 pregnancies were used to develop and validate the PAICS. The system achieved excellent performance in identifying 10 types of intracranial image pattern, with macro- and microaverage AUCs, respectively, of 0.933 (95% CI, 0.798-1.000) and 0.977 (95% CI, 0.970-0.985) for the internal validation image dataset, 0.902 (95% CI, 0.816-0.989) and 0.898 (95% CI, 0.885-0.911) for the external validation image dataset and 0.969 (95% CI, 0.886-1.000) and 0.981 (95% CI, 0.974-0.988) in the real-time scan setting. The performance of the PAICS was comparable to that of expert sonologists in terms of macro- and microaverage accuracy (P = 0.863 and P = 0.775, respectively), sensitivity (P = 0.883, P = 0.846) and AUC (P = 0.891, P = 0.788), but required significantly less time (0.025 s per image for PAICS vs 4.4 s for experts, P < 0.001).

CONCLUSIONS

Both in the image dataset and in the real-time scan setting, the PAICS achieved excellent diagnostic performance for various fetal CNS abnormalities. Its performance was comparable to that of experts, but it required less time. A CNN algorithm can be trained to detect fetal CNS abnormalities. The PAICS has the potential to be an effective and efficient tool in screening for fetal CNS malformations in clinical practice. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Methotrexate/mifepristone-combined with embryo removal in the treatment of caesarean scar pregnancy

OBJECTIVE

The aim of this study was to compare the effect of different administration modalities of methotrexate (MTX)/mifepristone in the initial medication stage, followed by embryo transfer in the treatment of caesarean scar pregnancy (CSP).

PATIENTS AND METHODS

A retrospective analysis of 66 CSP patients who received treatment in our hospital from January 2015 to July 2021 was performed, and participants were divided into three groups: Group one (n=14) received mifepristone followed by embryo removal treatment, Group two (n=29) received MTX followed by embryo removal, and Group three (n=23) received a methotrexate/mifepristone combined treatment followed by embryo removal. The basic findings were analysed, along with the curative effects between the three groups. Risk factors predicting additional treatment after initial intervention failure were analysed.

RESULTS

There were statistically significant differences in gestational age, hospitalization days, costs, myometrial thickness, cardiac activity, and mean sac diameter between groups (p<0.05) after grouping by eight weeks. The initial intervention success rates were 92.86%, 89.66%, and 65.22% in Group one, two, and three, respectively (p<0.05), while the complication rates were 14.29%, 6.90%, and 26.87%, respectively (p>0.05). After grouping according to eight weeks of gestational age, the difference in initial serum β-hCG between Group two and three was statistically significant (p<0.05). Mean sac diameter was a risk factor for additional treatment after initial intervention failure, with an odds ratio of 1.113 (p<0.05). A cut-off of 22.75 mm was a preferable indicator.

CONCLUSIONS

MTX/mifepristone followed by embryo removal is a reliable way to treat CSP. Mean sac diameter was a risk factor for additional treatment after initial intervention failure.

A Novel Chemical Binding Primer to Improve Dentin Bonding Durability

The dentin collagen matrix that is not completely enveloped by resin adhesive is vulnerable to degradation by intrinsic collagenases during the etch-and-rinse process, which contributes to the deterioration of the bonding interface. Current commercial adhesives have no functional components that can form covalent bonds to the dentin collagen matrix. In this study, a photocurable aldehyde, 4-formylphenyl acrylate (FA), was synthesized and for the first time applied as a primer in adhesive dentistry to covalently bind to collagen. Experimental groups with different concentrations of FA (1%, 3%, 5%, 7%, 9%) were prepared as primers. The cytotoxicity was evaluated by live/dead-cell staining and thiazolyl blue tetrazolium bromide assay. The interaction of FA with collagen was examined by attenuated total reflection Fourier transform infrared spectroscopy, hydroxyproline release under the degradation of type I collagenase, and thermogravimetric analysis. An optimal group was selected based on the degree of conversion of 2 universal adhesives and further divided depending on the treatment time (20 s, 30 s, 1 min, 2 min). The bonding performances were evaluated by microtensile strength before and after aging. Finally, the bonding interface was observed under confocal laser scanning microscopy and scanning electron microscope. The results indicated that FA demonstrated good biocompatibility, dentin modification capability, and infiltration. It not only effectively cross-linked dentin collagen to improve its stability against enzymatic hydrolysis and modify the adhesive interface but also potentially acted as a diluting monomer to induce deep penetration of adhesive resin monomers into the dentin. The bonding strength after aging was improved without jeopardizing the degree of conversion of 2 commercial adhesives. Such prominent advantages of using FA to improve the bonding performance promotes its further application in adhesive dentistry.

A 2-year locomotive exploration and scientific investigation of the lunar farside by the Yutu-2 rover

The lunar nearside has been investigated by many uncrewed and crewed missions, but the farside of the Moon remains poorly known. Lunar farside exploration is challenging because maneuvering rovers with efficient locomotion in harsh extraterrestrial environment is necessary to explore geological characteristics of scientific interest. Chang'E-4 mission successfully targeted the Moon's farside and deployed a teleoperated rover (Yutu-2) to explore inside the Von Kármán crater, conveying rich information regarding regolith, craters, and rocks. Here, we report mobile exploration on the lunar farside with Yutu-2 over the initial 2 years. During its journey, Yutu-2 has experienced varying degrees of mild slip and skid, indicating that the terrain is relatively flat at large scales but scattered with local gentle slopes. Cloddy soil sticking on its wheels implies a greater cohesion of the lunar soil than encountered at other lunar landing sites. Further identification results indicate that the regolith resembles dry sand and sandy loam on Earth in bearing properties, demonstrating greater bearing strength than that identified during the Apollo missions. In sharp contrast to the sparsity of rocks along the traverse route, small fresh craters with unilateral moldable ejecta are abundant, and some of them contain high-reflectance materials at the bottom, suggestive of secondary impact events. These findings hint at notable differences in the surface geology between the lunar farside and nearside. Experience gained with Yutu-2 improves the understanding of the farside of the Moon, which, in return, may lead to locomotion with improved efficiency and larger range.

[Gut microbiome composition in pre-adolescent children with different meat consumption patterns]

OBJECTIVE

To compare the composition of gut microbiome in pre-adolescent children with different meat consumption patterns.

METHODS

This study was conducted among 44 healthy school-age children (age range 8-10 years) in Shenzhen. According to the monthly intake frequency ratio of white meat and red meat, the children were divided into red-meat group (n=15), balanced group (n=16) and white-meat group (n=13). The Food Frequency Questionnaire (FFQ) was used to investigate the children's diet, and samples of morning feces were collected to study the gut microbiome. The fecal DNA was extracted and amplified, and the composition of the intestinal microbiome of the children was analyzed using Illumina Miseq high-throughput sequencing.

RESULTS

The children in red meat and white meat groups showed significantly lower abundance and diversity of gut microbiota than those with a balanced diet (P < 0.05). LEfSe analysis of the genus in the fecal samples showed that Escherichia-Shigella, Coprobacillus and Peptoniphilus were enriched in red-meat group and Holdemanella was enriched in the white-meat group as compared with the balanced group. In the samples of the balanced group, 31 and 25 genus (such as Laurespirillum and Rumenococcus) were significantly enriched as compared with the samples of the red-meat group and the white-meat group, respectively. Prediction of the gut microbiota KEGG pathway using PICRUSt2 suggested that compared with that in the balanced group, the gut microbiota in red-meat group had significant activation of the pathways involving lipopolysaccharide biosynthesis (P < 0.01), arachidonic acid metabolism (P < 0.01), thyroid hormone synthesis (P < 0.001), and carbohydrate digestion and absorption (P < 0.05). But compared with the white-meat group, the red-meat group showed only significant activation of the pathways of arachidonic acid metabolism (P < 0.05) and thyroid hormone synthesis (P < 0.05).

CONCLUSION

The preference of red meat and white meat consumption may significantly reduce the abundance and diversity of gut microbiota in pre-adolescent children. A red meat-rich diet may cause enrichment of Escherichia-Shigella and significant activation of lipopolysaccharide biosynthesis pathway, suggesting the potential benefit of a balanced diet for pre-adolescent children.

Giant Biquadratic Exchange in 2D Magnets and Its Role in Stabilizing Ferromagnetism of NiCl_{2} Monolayers

Two-dimensional (2D) van der Waals (vdW) magnets provide an ideal platform for exploring, on the fundamental side, new microscopic mechanisms and for developing, on the technological side, ultracompact spintronic applications. So far, bilinear spin Hamiltonians have been commonly adopted to investigate the magnetic properties of 2D magnets, neglecting higher order magnetic interactions. However, we here provide quantitative evidence of giant biquadratic exchange interactions in monolayer NiX_{2} (X=Cl, Br and I), by combining first-principles calculations and the newly developed machine learning method for constructing Hamiltonian. Interestingly, we show that the ferromagnetic ground state within NiCl_{2} single layers cannot be explained by means of the bilinear Heisenberg Hamiltonian; rather, the nearest-neighbor biquadratic interaction is found to be crucial. Furthermore, using a three-orbitals Hubbard model, we propose that the giant biquadratic exchange interaction originates from large hopping between unoccupied and occupied orbitals on neighboring magnetic ions. On a general framework, our work suggests biquadratic exchange interactions to be important in 2D magnets with edge-shared octahedra.

Untargeted lipidomics analysis in women with intrahepatic cholestasis of pregnancy: a cross-sectional study

OBJECTIVE

To compare the plasma lipid profiles in women with normal pregnancies and those with mild or severe intrahepatic cholestasis of pregnancy (ICP). Our goal was to reveal lipidome-wide alterations in ICP and delve into the pathogenesis of ICP from a lipid metabolism perspective.

DESIGN

Cross-sectional study, including women with normal pregnancies, women with mild ICP and women with severe ICP.

SETTING

Gansu Provincial Hospital.

POPULATION

Women with ICP were recruited from October 2019 to March 2020 in Gansu, China.

METHODS

Untargeted lipidomics was used to analyse differentially expressed plasma lipids in controls, in women with mild ICP and in women with severe ICP (n = 30 per group). For lipidomics, liquid chromatography and Q-Exactive Plus Orbitrap mass spectrometry were performed.

MAIN OUTCOME MEASURES

Differentially expressed lipids.

RESULTS

Thirty-three lipids were differentially expressed in the severe and mild ICP groups, compared with the control group, and 20 of those were sphingolipids (ceramide, six species; sphingomyelin, 14 species). All differentially expressed sphingolipids in women with mild ICP were also differentially expressed in women with severe ICP; the fold change and significance of the differential expression were positively correlated with disease severity.

CONCLUSIONS

We systematically characterized the lipidome-wide alterations in mild and severe ICP groups. The results indicated a link between ICP and disordered sphingolipid homeostasis.

TWEETABLE ABSTRACT

Abnormal sphingolipid metabolism is involved in the pathogenesis of ICP.

[Outcome of radiotherapy for low-risk early-stage patients with extranodal NK/T-cell lymphoma, nasal-type]

Objective: To evaluate the prognosis and determine the failure patterns after radiotherapy for low-risk early-stage patients with extranodal NK/T-cell lymphoma, nasal-type (ENKTCL). Methods: A total of 557 patients from 2000-2015 with low-risk early-stage ENKTCL who received radiotherapy (RT) with or without chemotherapy (CT) from China Lymphoma Collaborative Group were retrospectively reviewed. Among them, 427 patients received combined modality therapy, whereas 130 patients received RT alone. Survivals were calculated by Kaplan-Meier method and compared with Log-rank test. Overall survival (OS) was compared with age and sex-matched general Chinese population using expected survival and standardized mortality ratio (SMR). Cox stepwise regression model was used for multivariate analysis. Results: The 5-year OS and progression-free survival (PFS) were 87.2% and 77.2%. The SMR was 3.59 (P<0.001) at 1 year after treatment, whereas it was 1.50 at 4 years after treatment, without significant difference between ENKTCL group and country-matched general population (P=0.146). Compared with RT alone, CMT did not result in significantly superior 5-year OS (87.0% vs 87.4%, P=0.961) or PFS (76.1% vs 80.7%, P=0.129). Local failure (11.5%, 64/557) and distant failure (10.8%, 60/557) were the main failure modes, while regional failure was rare (2.9%, 16/557). The 5-year locoregional control rate (LRC) was 87.2% for the whole group, with 89.5% for ≥50 Gy versus 73.7% for <50 Gy (P<0.001). Radiotherapy dose was an independent factor affecting LRC(P<0.05). Conclusions: Radiotherapy achieves a favorable prognosis in patients with low-risk early-stage ENKTCL. The incidence of either locoregional or distant failure is low. Radiation dose still is an important prognostic factor for LRC.

Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p^{↑}+p Collisions at sqrt[s]=200 GeV

Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in p^{↑}+p collisions at sqrt[s]=200  GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.

[Epidemiological characteristics of close contacts of COVID-19 cases and infection-related risk factors in Beijing]

Objective: To analyze the epidemiological characteristics of close contacts of COVID-19 cases and infection-related risk factors in Beijing and provide evidences for COVID-19 prevention and control. Methods: A total of 20 681 close contacts of COVID-19 cases, who had exposures during January 6, 2020 to February 15, 2021, were traced in Beijing. The information about their demographic characteristics, exposure history, and quarantine outcomes were collected and analyzed with descriptive statistics. The logistic regression analysis was used to identify the risk factors for COVID-19. Results: The infection rate SARS-CoV-2 in close contacts was 2.16% (447/20 681). The age M(P₂₅, P₇₅) was 35 (27, 49) years. The majority of the close contacts were aged 20-59 years, accounting for 81.77% (16 912/20 681). Centralized isolation was the major type of medical observation, accounting for 82.15% (16 989/20 681). Among the exposure types, working and studying in the same room (16.06%, 3 322/20 681), sharing same transport vehicle (12.88%, 2 664/20 681), performing diagnosis and treatment nursing (7.80%,1 612/20 681), and living together (7.23%,1 495/20 681), accounting for 43.96% (9 093/20 681). The index cases included staff (19.34%, 3 999/20 681), the unemployed (17.34%, 3 586/20 681), people engaged in business service (13.85%, 2 864/20 681), people engaged in food service (10.77%, 2 228/20 681), their close contacts accounted for 61.30% (12 677/20 681). Multivariate logistic regression analysis showed that compared with other types of exposure, the risk factors for infection were having meal together (OR=3.96, 95%CI: 2.30-6.83) and living together (OR=6.41, 95%CI:4.48-9.17); Compared with the other occupations, the index case being engaged in food service (OR=3.06, 95%CI:1.29-7.25) and teacher (OR=4.94, 95%CI:1.43-17.08) were risk factors for the infection. Conclusions: The main environmental exposure types of SARS-CoV-2 infection in close contacts were having meal together and living together. Contact with the index case being engaged in food service and teacher increased the risk for COVID-19. Comprehensive prevention and control measures such as centralized isolation and vaccination should be continued.

Biological modulations to facilitate graft healing in anterior cruciate ligament reconstruction (ACLR), when and where to apply? A systematic review

Background

When and where to apply the biological modulations is effective to promote healing in the anterior cruciate ligament (ACL) reconstruction remains unclear.

Purpose

To perform a systematic review of preclinical animal studies on biological modulation in anterior cruciate ligament reconstruction (ACLR) concerning the time and site of delivery.

Study design

Systematic review of controlled laboratory studies.

Methods

PubMed, Ovid, and Scopus were searched until December 2020 using a combination of keywords and their synonym to retrieve all animal studies about biological modulation in ACLR. Studies that assessed mechanical strength after ACLR and compared with negative control were included. The methodological quality of animal studies was evaluated.

Results

33 studies were included in this review and the majority reported mechanical strength improvement. 79 ​% of studies applied the biological modulations intra-operatively with different delivery systems used. For 21 ​% of post-operative delivery studies, intermittent delivery was tried. 21 of the included studies directly applied the biological modulations in the bone tunnels, 5 studies applied intra-articularly while 7 studies applied both in the bone tunnels and intra-articular part. Biological modulations applied intra-operatively and those applied in both parts showed better mechanical strength increase. A shift of the failure mode of pull-out from the bone tunnel in the early healing phase, to mid-substance rupture in the later phase was observed in most studies.

Conclusion

The improvement of the mechanical strength depends on how the biological modulations (delivery phase, delivery site, delivery form) are applied. The intra-operative delivery showed an overall higher mechanical strength increase and bone tunnel only delivery or intra-articular and bone tunnel both delivery are preferred than intra-articular only delivery. In addition, intra-articular and bone tunnel both delivery can have better mechanical strength increase for a long follow-up time. Thus, intra-operative application with a carrier to control release rate in both parts should be recommended. Further studies are needed to achieve a better healing outcome and more attention should be given to the intra-articular remodeling of the graft along with the tendon bone healing to increase the final mechanical strength.

The Translational potential of this article

Here, a systematic review of preclinical evidence of the time, site and the method the biological modulations being applied for ACLR to improve the graft healing would be performed. After reviewing the available studies, a choice of when and where to apply the biological modulations can achieve better mechanical strength after ACLR can be obtained. It provides evidence for both researchers and clinicians to decide when and where to apply the biological modulations can achieve their best effectiveness for ACLR before implementing. Promoting graft healing with targeted time and targeted site may reduce the risk of graft failure, safeguard return to sport.

Development of a Simple Single-Acupoint Electroacupuncture Frame and Evaluation of the Acupuncture Effect in Rabbits

To reduce the circulation path of the output current of traditional electroacupuncture (TEA) process in the body, a simple single-acupoint electroacupuncture (SEA) frame was designed and the acupuncture effect of SEA was evaluated through Hou-san-li (ST-36) and Qian-san-li (LI-10) acupoints. Forty-two healthy New Zealand rabbits were randomly divided into seven groups and underwent acupuncture for 20 min in an awake state. Blood samples aseptically collected from the ear vein 3 h before acupuncture and 0, 3, 6, 9, 12 and 24 h after acupuncture were used for the detection of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase MB (CK-MB) and motilin (MTL) in serum. The simple SEA frame was developed successfully, and the acupuncture results showed that the serum AST and ALT levels were significantly higher at 3 h after TEA with high frequency (p < 0.01) compared with the control group. Regarding serum CK-MB levels, no significant differences were found after SEA or TEA stimulation (p > 0.05). Serum MTL levels were significantly increased at 0 h after SEA and TEA (p < 0.05), but there were no significant differences at other time points after SEA and TEA treatment (p > 0.05). SEA not only maintains the effect of TEA but also shortens the circulation loop of the electroacupuncture (EA) current in the body, which effectively avoids body injury.

[1-deoxynojirimycin alleviates liver fibrosis induced by type 2 diabetes in mice]

OBJECTIVE

To investigate the effect of 1-deoxynojirimycin (DNJ) for improving diabetic liver fibrosis and explore the underlying mechanism.

METHODS

Mouse models of type 2 diabetes were established in 10 Kunming mice by high-fat diet feeding for 8 weeks and intraperitoneal injection of STZ, with 5 mice receiving intraperitoneal injection of citrate buffer solution with normal feeding as the control group. The mouse models were randomized into two groups (n=5) for further highfat feeding (model group) and additional treatment with 10% DNJ in drinking water (200 mg · kg^-1 per day; DNJ group) for 8 weeks. The mice were monitored for changes in body weight (BW), blood glucose, serum total cholesterol (TC), triglyceride (TG) and superoxide dismutase (SOD) levels. The pathological changes in the liver tissue were observed using HE and Sirius Red staining, and the solubility of collagens in the liver tissues was determined. The expression levels of MCP-1, TNF-α, IL-1β and TGF-β1 mRNA were detected with real-time PCR, and the protein expressions of α-SMA and collagen2 (ColA2) were determined with Western blotting. In the in vitro experiment, mouse fibroblasts L929 cells were pretreated with DNJ (10 μg/ mL) or PBS for 30 min followed by culture in high-glucose medium for 24 h, and the level of ROS production was measured using dihydroethidium (DHE) staining.

RESULTS

In the mouse model of type 2 diabetes, DNJ treatment significantly lowered serum level of glucose, TC, and TG (P < 0.05) and increased serum SOD activity (P < 0.05). DNJ obviously attenuated liver fibrosis in the diabetic mice, as shown by alleviated cross-linking of collagens and reduced contents of pepsin-solubilized collagen (PSC) and total collagen (P < 0.05). DNJ treatment also significantly reduced the overexpression of the proinflammatory cytokines and fibrosis-related cytokines induced by diabetes (P < 0.05). In L929 cells exposed to high glucose, pretreatment with DNJ significantly lowered the intensity of red fluorescence in DHE staining.

CONCLUSION

DNJ can attenuate type 2 diabetes-induced liver fibrosis in mice through its hypoglycemic, anti-inflammatory and anti-oxidative effects.

Observation of D_{s}^{±}/D^{0} Enhancement in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

We report on the first measurement of charm-strange meson D_{s}^{±} production at midrapidity in Au+Au collisions at sqrt[s_{NN}]=200  GeV from the STAR experiment. The yield ratio between strange (D_{s}^{±}) and nonstrange (D^{0}) open-charm mesons is presented and compared to model calculations. A significant enhancement, relative to a pythia simulation of p+p collisions, is observed in the D_{s}^{±}/D^{0} yield ratio in Au+Au collisions over a large range of collision centralities. Model calculations incorporating abundant strange-quark production in the quark-gluon plasma and coalescence hadronization qualitatively reproduce the data. The transverse-momentum integrated yield ratio of D_{s}^{±}/D^{0} at midrapidity is consistent with a prediction from a statistical hadronization model with the parameters constrained by the yields of light and strange hadrons measured at the same collision energy. These results suggest that the coalescence of charm quarks with strange quarks in the quark-gluon plasma plays an important role in D_{s}^{±}-meson production in heavy-ion collisions.

O-137 Salpingectomy versus neosalpingostomy in women with hydrosalpinx: a prospective cohort study with long-term follow-up

Study question

What is the comparative effectiveness between salpingectomy and neosalpingostomy in the treatment of bilateral severe hydrosalpinx?

Summary answer

In women with bilateral severe hydrosalpinx, salpingectomy combined with In Vitro Fertilization (IVF) treatment resulted in a higher cumulative live birth rate than neosalpingostomy.

What is known already

Hydrosalpinx accounts for 25% to 35% of female subfertility and has a negative effect on pregnancy rates in women who undergo IVF. So far salpingectomy before in vitro fertilization treatment has been suggested for the treatment of hydrosalpinx in order to improve the chance of a live birth. Previous studies have reported a pooled live birth rate of 25% through natural conception after neosalpingostomy and an ongoing pregnancy rate of 55.8% after salpingectomy with IVF. Direct comparison of the cumulative live birth rate after salpingectomy versus neosalpingostomy, both followed by IVF is lacking.

Study design, size, duration

We performed a single center, prospective comparative cohort study in the International Peace Maternity and Child Health Hospital affiliated to Shanghai Jiao Tong University School of Medicine, China. We studied women diagnosed with tubal subfertility with bilateral hydrosalpinx between January 2005 and December 2012. Based on a shared decision approach, they had bilateral salpingectomy or neosalpingostomy followed by IVF. They were annually followed up until July 2020 for the occurrence of live birth.

Participants/materials, setting, methods

Out of 113 women, 55 had bilateral salpingectomy and 58 had bilateral neosalpingostomy. Primary outcome was cumulative live birth rate, defined as the cumulative birth rate of the first living neonate through either natural conception or in vitro fertilization. Both intention-to-treat (ITT) and per-protocol (PP) analysis were processed. Cox proportional hazards regression model with potential variables was performed to identify predictors of successful live birth.

Main results and the role of chance

Baseline characteristics were comparable between two groups. There were 42 live births in the salpingectomy and 36 in the neosalpingostomy group. When the result of IVF was incorporated (55/55 in salpingectomy group and 25/58 in neosalpingostomy group underwent IVF), salpingectomy resulted in a higher cumulative live birth rate (85.3% vs 76.0%; hazard ratio of the whole survival curve, 2.18; 95% CI, 1.37 - 3.45; P = 0.001), a lower risk of ectopic pregnancy (1.8% vs 20.7%; risk ratio, 0.07; 95% CI, 0.01 - 0.57; P = 0.013), and a shorter time to live birth (19 [14,27] versus 36 [17,76] months, P = 0.001).The number of live birth rates after natural conception was 0% (0/55) in the salpingectomy group and 28% (16/58) in neosalpingostomy group.The results of PP analyses were comparable with the ITT analyses apart from the biochemical pregnancy rate and the overall live birth rate, they were higher (the former: 76% (42/55) versus 58% (29/50), P = 0.045; the latter: 76% (42/55) versus 56% (28/50), P = 0.027) in salpingectomy group.

Limitations, reasons for caution

This is an observational study. The small sample size along with the data was obtained from a cohort study in a single center.

Wider implications of the findings

In women with confirmed bilateral severe hydrosalpinx, salpingectomy followed by IVF results in a higher cumulative live birth rate and decreases the risk of EP as compared to neosalpingostomy. However, neosalpingostomy is the only option to achieve a live birth by natural conception that should be discussed with patients preoperatively.

Trial registration number

not applicable

Investigation on the mechanism of p38MAPK in the failure of autogenous arteriovenous fistula caused by stenosis

The present study aimed to probe into the mechanism of p38MAPK in the failure of autogenous arteriovenous fistula (AVF) caused by stenosis. A total of 24 patients with maintenance hemodialysis and the autologous AVF as the hemodialysis route were enrolled in the present study. In the experimental group, the internal fistula operation mode was the end-to-side anastomosis, and patients were those who needed autogenous AVF repair due to the venous hyperplasia and stenosis of the internal fistula anastomosis (n = 12). The control group was composed of patients who underwent autogenous AVF surgery for the first time (n = 12). The discarded venous tissues in each group were used for immunohistochemistry and Western blot detection of ASK1, P38, and ATF-2. SPSS 17.0 and GraphPad Prism 5 software were adopted for data analysis. The measurement data were expressed as means ± standard deviations ( x ± s), and P < 0.05 was considered statistically significant. The results of immunohistochemistry staining: the expressions of ASK1, P38, and ATF-2 in the experimental group were significantly higher than those in the control group, and the differences were statistically significant (P < 0.01). The results of Western blot: the expression of P38 in the experimental group was significantly higher than that in the control group, and the difference was statistically significant (P < 0.05). There was no significant difference in the expression of ASK1 and ATF-2 between the experimental group and the control group (P > 0.05). In stenotic AVF, the expressions of ASK1, P38, and ATF-2 all significantly increased, indicating that the p38MAPK signaling pathway might be involved in the formation of venous stenosis in AVF, and the p38MAPK signaling pathway might become a therapeutic target in preventing and treating the vascular stenosis in the fistula.

Measurement of e^{+}e^{-} Momentum and Angular Distributions from Linearly Polarized Photon Collisions

The Breit-Wheeler process which produces matter and antimatter from photon collisions is experimentally investigated through the observation of 6085 exclusive electron-positron pairs in ultraperipheral Au+Au collisions at sqrt[s_{NN}]=200  GeV. The measurements reveal a large fourth-order angular modulation of cos4Δϕ=(16.8±2.5)% and smooth invariant mass distribution absent of vector mesons (ϕ, ω, and ρ) at the experimental limit of ≤0.2% of the observed yields. The differential cross section as a function of e^{+}e^{-} pair transverse momentum P_{⊥} peaks at low value with sqrt[⟨P_{⊥}^{2}⟩]=38.1±0.9  MeV and displays a significant centrality dependence. These features are consistent with QED calculations for the collision of linearly polarized photons quantized from the extremely strong electromagnetic fields generated by the highly charged Au nuclei at ultrarelativistic speed. The experimental results have implications for vacuum birefringence and for mapping the magnetic field which is important for emergent QCD phenomena.

Association of improved overall survival with decreased distant metastasis following asparaginase-based chemotherapy and radiotherapy for intermediate- and high-risk early-stage extranodal nasal-type NK/T-cell lymphoma: a CLCG study

BACKGROUND

This study evaluated the survival benefit of asparaginase (ASP)-based versus non-ASP-based chemotherapy combined with radiotherapy in a real-world cohort of patients with early-stage extranodal nasal-type natural killer/T-cell lymphoma (ENKTCL).

PATIENTS AND METHODS

We identified 376 patients who received combined radiotherapy with either ASP-based (ASP, platinum, and gemcitabine; n = 286) or non-ASP-based (platinum and gemcitabine; n = 90) regimens. The patients were stratified into low-, intermediate-, and high-risk groups using the early stage-adjusted nomogram-revised risk index. Overall survival (OS) and distant metastasis (DM)-free survival (DMFS) between the chemotherapy regimens were compared using inverse probability of treatment weighting (IPTW) and multivariable analyses.

RESULTS

ASP-based (versus non-ASP-based) regimens significantly improved 5-year OS (84.5% versus 73.2%, P = 0.021) and DMFS (84.4% versus 74.5%, P = 0.014) for intermediate- and high-risk patients, but not for low-risk patients in the setting of radiotherapy. Moreover, ASP-based regimens decreased DM, with a 5-year cumulative DM rate of 14.9% for ASP-based regimens compared with 25.1% (P = 0.014) for non-ASP-based regimens. The survival benefit of ASP-based chemotherapy and radiotherapy remained consistent after adjusting the confounding variables using IPTW and multivariate analyses; additional sensitivity analyses confirmed these results.

CONCLUSIONS

The findings provided support for ASP-based chemotherapy and radiotherapy as a first-line treatment strategy for intermediate- and high-risk early-stage ENKTCL.

Two-dimensional overdamped fluctuations of the soft perovskite lattice in CsPbBr3

Lead halide perovskites exhibit structural instabilities and large atomic fluctuations thought to impact their optical and thermal properties, yet detailed structural and temporal correlations of their atomic motions remain poorly understood. Here, these correlations are resolved in CsPbBr₃ crystals using momentum-resolved neutron and X-ray scattering measurements as a function of temperature, complemented with first-principles simulations. We uncover a striking network of diffuse scattering rods, arising from the liquid-like damping of low-energy Br-dominated phonons, reproduced in our simulations of the anharmonic phonon self-energy. These overdamped modes cover a continuum of wave vectors along the edges of the cubic Brillouin zone, corresponding to two-dimensional sheets of correlated rotations in real space, and could represent precursors to proposed two-dimensional polarons. Further, these motions directly impact the electronic gap edge states, linking soft anharmonic lattice dynamics and optoelectronic properties. These results provide insights into the highly unusual atomic dynamics of halide perovskites, relevant to further optimization of their optical and thermal properties.

POS0136 ROLES OF AUTOPHAGY IN THE PATHOGENESIS OF PRIMARY GOUTY ARTHRITIS

Background:

Gout is a chronic autoinflammatory disease caused by monosodium urate (MSU) crystal deposition [1].Acute gout is characterized by an acute inflammatory reaction that resolves spontaneously within a few days[2], which is one of the distinguishing features of gout compared to other arthropathies or self-inflammatory diseases. Autophagy is a lysosomal degradation pathway that is essential for cellular growth, survival, differentiation, development and homeostasis [3]. Studies have demonstrated that autophagy might play a key role in the pathogenesis of primary gouty arthritis (GA) [4-7]. However, the roles of autophagy in the development of gout have not yet been elucidated.

Objectives:

The aim of our study was to investigate the changes in autophagy-related gene (ATG) mRNA and protein in patients and the clinical importance of these genes in primary gouty arthritis (GA) and to explore the roles of autophagy in the pathogenesis of GA.

Methods:

The mRNA and protein expression levels of ATGs (ATG3, ATG7, ATG10, ATG5, ATG12, ATG16L1, ATG4B and LC3-2) were measured in peripheral blood mononuclear cells (PBMCs) from 196 subjects, including 57 acute gout patients (AG group), 57 intercritical gout patients (IG group) and 82 healthy control subjects (HC group). The relationship between ATG expression levels and laboratory features was analyzed in GA patients.

Results:

The expression levels of ATG4B, ATG5, ATG12, ATG16L1, ATG10 and LC3-2 mRNA were much lower in the AG group than in the IG and HC groups (p<0.05), while the ATG7 mRNA level was much higher in the AG group than in the IG and HC groups (p<0.05). The protein expression levels of LC3-2, ATG3, ATG7 and ATG10 were much higher in the AG group than in the other groups, while those of ATG5, ATG12, ATG16L1 and ATG4B were far lower in the AG group than in the other groups (p<0.05). In GA patients, the levels of ATG mRNA and protein correlated with laboratory inflammatory and metabolic indexes.

Conclusion:

Altered ATG expression suggests that autophagy is involved in the pathogenesis of GA and participates in regulating inflammation and metabolism.

References:

[1]Dalbeth N, Choi HK, Joosten LAB, Khanna PP, Matsuo H, Perez-Ruiz F, et al. Gout. Nat Rev Dis Primers. 2019;5: 69.doi:10.1038/s41572-019-0115-y.

[2]Schauer C, Janko C, Munoz LE, Zhao Y, Kienhöfer D, Frey B, et al. Aggregated neutrophil extracellular traps limit inflammation by degrading cytokines and chemokines. Nat Med. 2014;20: 511-517.doi:10.1038/nm.3547.

[3]Han Y, Zhang L, Xing Y, Zhang L, Chen X, Tang P, et al. Autophagy relieves the function inhibition and apoptosis-promoting effects on osteoblast induced by glucocorticoid. Int J Mol Med. 2018;41: 800-808. doi:10.3892/ijmm.2017.3270.

[4]Yang QB, He YL, Zhong XW, Xie WG, Zhou JG. Resveratrol ameliorates gouty inflammation via upregulation of sirtuin 1 to promote autophagy in gout patients. Inflammopharmacology. 2019;27: 47-56.doi:10.1007/s10787-018-00555-4.

[5]Mitroulis I, Kambas K, Chrysanthopoulou A, Skendros P, Apostolidou E, Kourtzelis I, et al. Neutrophil extracellular trap formation is associated with IL-1β and autophagy-related signaling in gout. PLoS One. 2011;6: e29318.doi: 10.1371/journal.pone.0029318.

[6]Crişan TO, Cleophas MCP, Novakovic B, Erler K, van de Veerdonk FL, Stunnenberg HG, et al. Uric acid priming in human monocytes is driven by the AKT-PRAS40 autophagy pathway. Proc Natl Acad Sci U S A. 2017;114: 5485-5490.doi:10.1073/pnas.1620910114.

[7]Lee SS, Lee SW, Oh DH, Kim HS, Chae SC, Kim SK. Genetic analysis for rs2241880(T > C) in ATG16L1 polymorphism for the susceptibility of Gout. J Clin Rheumatol. 2019;25: e113-e115.doi:10.1097/rhu.0000000000000685.

Disclosure of Interests:

Yu-Qin Huang: None declared, Quan-Bo Zhang Grant/research support from: National Natural Science Foundation of China(General Program) (no.81974250) and Science and Technology Plan Project of Sichuan Province (no.2018JY0257), Jian-Xiong Zheng: None declared, gui-lin jian: None declared, tao-hong liu: None declared, Xin He: None declared, fan-ni xiao: None declared, qin xiong: None declared, Yu-Feng Qing Grant/research support from: Science and Technology Project of Nanchong City (no.18SXHZ0522)

Responses of growth, photosynthesis and related physiological characteristics in leaves of Acer ginnala Maxim. to increasing air temperature and/or elevated O3

Regional warming and atmospheric ozone (O₃ ) pollution are two of the most important environmental issues, and commonly coexist in many areas. Both factors have an intense impact on plants. However, little information is available on the combined and interactive effects of air warming and elevated O₃ concentrations on physiological characteristics of plants. To explore this issue, we studied variations in growth, photosynthesis and physiological characteristics of leaves of Acer ginnala seedlings exposed to control (ambient temperature and O₃ ), increasing air temperature (ambient temperature + 2 °C), elevated O₃ (ambient O₃ concentration + 40 ppb) and a combination of the two abiotic factors at different phenological stages by using open-top chambers. The results showed that increasing air temperature had no significant effect on growth, but increased photosynthesis and antioxidant enzyme activity at the leaf unfolding and defoliation stages. In contrast, elevated O₃ decreased growth and photosynthesis and caused oxidative stress injury in A. ginnala leaves at each phenological stage. The combination of increasing air temperature and elevated O3 improved growth and net photosynthetic rates of tested plants and alleviated the oxidative stress compared to O₃ alone. Our findings demonstrated that moderate warming was beneficial to A. ginnala at leaf unfolding and defoliation stages, and alleviated the adverse effects of O₃ stress on growth, photosynthesis and the antioxidant system. These results will provide a theoretical reference and scientific basis for the adaptation and response of A. ginnala under regional air warming and atmospheric O₃ pollution.

[Sleep-disordered breathing in patients with chronic heart failure before and after heart transplantation]

Objective: To explore the characteristics of sleep-disordered breathing (SDB) in chronic heart failure patients waiting for heart transplantation and the changes of SDB after transplantation. Methods: From September 2018 to December 2019, 34 patients with chronic heart failure were prospectively enrolled into this study, who were hospitalized for waiting for heart transplantation in the departments of cardiovascular medicine and cardiovascular surgery, Renmin Hospital of Wuhan University. All of them received portable sleep physiological monitoring. The characteristics of their SDB were analyzed before and after heart transplantation. Results: Of the 34 patients waiting for heart transplantation, 22 had central sleep apnea, 4 had obstructive sleep apnea and 8 had no SDB. The cycle length of Cheyne-Stokes respiration was negatively correlated with left ventricular ejection fraction. After heart transplantation, 15 patients received repeat sleep physiological monitoring and their results showed that the SDB was significantly improved, with the elimination of Cheyne-Stokes respiration. Conclusions: Patients waiting for heart transplantation had a high prevalence of SDB, with Cheyne-Stokes respiration with central sleep apnea as the main type. However, heart transplantation may eliminate the Cheyne-Stokes respiration in patients with chronic heart failure.

Medical ozone induces proliferation and migration inhibition through ROS accumulation and PI3K/AKT/NF-κB suppression in human liver cancer cells in vitro

BACKGROUND

Hepatocellular carcinoma is one of the most common malignancies and leading cancer-associated deaths worldwide. Ozone has been proposed as a promising therapeutic agent in the treatment of various disorders.

PURPOSE

The purpose of this paper is to assess the potential anticancer effects of the ozone on liver cancer cells.

METHOD

The liver cancer cell line of bel7402 and SMMC7721 was used in this study. Proliferation was evaluated using the CCK-8 and the colony formation assay. Wond healing assay and transwell assay without Matrigel were used to evaluate their migration ability. Flow cytometry was used for cell cycle analysis and reactive oxygen species (ROS) determination. Glutathione detection kit was used for measurement of glutathione level. Protein expression was estimated by western blot analysis.

RESULTS

Ozone treatment inhibited liver cancer cell proliferation, colony formation. Ozone induced G2/M phase cell cycle arrest, which could be elucidated by the change of protein levels of p53, p21, Cyclin D1, cyclin B1, cdc2, and CDK4. We also found that ozone treatment inhibited migration ability by inhibiting EMT-relating protein. Ozone also induced ROS accumulation and decreased glutathione level decreased, which contributed to the inactivation of the PI3K/AKT/NF-κB pathway. Finally, we found that pre-treatment of liver cancer cells with N-acetylcysteine resisted ozone-induced effects.

CONCLUSIONS

Ozone restrains the proliferation and migration potential and EMT process of liver cancer cells via ROS accumulation and PI3K/AKT/NF-κB suppression.

[The roles of two HIV self-testing models in promoting HIV-testing among men who have sex with men]

Objective: To evaluate the roles between two different HIV self-testing models in promoting HIV-testing among men who have sex with men (MSM). Methods: This paper focuses on two HIV self-testing service models. The first; is the online self-testing model (HIV self-testing conventional model) with the sexual health promotion network platform. The other one is an innovative HIV self-testing model (secondary distribution model), based on the previous program. The two different self-testing models, including the number of indexes and alters, the positive rate, and the demographics of indexes and alters, are compared. The influence of volunteers with or without leadership on the number of HIV self-test kits distributed or self-use is analyzed through the leadership survey scale. Results: The return rates of HIV self-testing results in the two models are 94.7%(323/341) and 99.2%(1 141/1 150), respectively, within 30 days. The proportion of alters in the secondary distribution is significantly higher (45.9%,281/612) than the conventional HIV self-testing (6.3%,20/318). In the secondary distribution model, the difference between the number of indexes and alters indicators including age, marital status, residence, sex orientation, anal sex with men in the past six months, and HIV test are statistically significant (χ² test, all P<0.05). The opinion leader of MSM has significantly impacted the promotion of HIV self-testing (P<0.05). Conclusions: Both models can promote HIV self-testing, result return, and HIV positive detection among MSM. In terms of expanding the testing and detection of HIV positive, the secondary distribution mode shows more obvious advantages, which significantly promotes a large number of MSM who have never been tested for HIV to undergo HIV testing. Influential indexes have a significant effect on increasing the HIV testing rate and promoting HIV testing among MSM.

The gene NtMYC2a acts as a 'master switch' in the regulation of JA-induced nicotine accumulation in tobacco

The biosynthesis and transport of nicotine has been shown to be coordinately upregulated by jasmonate (JA). MYC2, a member of basic helix-loop-helix (bHLH) transcription factor family, is well-documented as the core player in the JA signalling pathway to regulate diverse plant development processes. Four MYC2 genes were found in the tobacco genome, NtMYC2a/2b and 1a/1b. In this study, we tested whether one of them, NtMYC2a, acts as a 'master switch' in the regulation of nicotine biosynthesis and transport in tobacco. We generated NtMYC2a knockout tobacco plants using the CRISPR-Cas9 technique and analysed the effect of NtMYC2a knockout on expression of the nicotine biosynthesis genes (NtAO, NtQS, NtPMT1a, NtQPT2, NtODC2, NtMPO1, NtA622 and NtBBLa) and transport genes (NtMATE2 and NtJAT1), as well as leaf accumulation of nicotine in the NtMYC2a knockout plants. We found that all the nicotine biosynthesis and transport genes tested in this study were significantly downregulated (>50% reduction compared with wild-type control) in the NtMYC2a knockout plants. Moreover, the leaf nicotine content in knockout plants was dramatically reduced by ca 80% compared with the wild-type control. These results clearly show that NtMYC2a acts as a 'master switch' to coordinate JA-induced nicotine accumulation in tobacco and suggests that NtMYC2a might play an important role in tobacco nicotine-mediated defence against herbivory.