The role and molecular mechanism of gut microbiota in Graves' orbitopathy

PURPOSE

Graves' orbitopathy (GO) is an autoimmune orbital disorder. Gut microbiota dysfunction plays a vital role in autoimmune diseases, including Graves' disease (GD) and GO. In the present study, we aimed to investigate the change of gut microbiota in GD/GO using mouse model.

METHODS

The murine model of GD/GO was established by the challenge of adenovirus expressing thyroid-stimulating hormone (TSH) receptor (TSHR) (Ad-TSHR). The histological changes of orbital and thyroid tissues were analyzed by hematoxylin and eosin (H&E), Masson staining, and immunohistochemistry (IHC) staining. The fecal samples were collected for 16S rRNA gene sequencing and bioinformatics analysis.

RESULTS

The GD/GO model was established successfully, as manifested as the broadened eyelid, exophthalmia and conjunctive redness, severe inflammatory infiltration among thyroid glands and between extraocular muscle space, hypertrophic extraocular muscles, elevated thyroxine (T4) and decreased TSH, and positive CD34, CD40, collagen I, and α-SMA staining. A total of 222 operational taxonomic units (OUTs) were overlapped between mice in the Ad-NC and Ad-TSHR groups. The microbial composition of the samples in the two groups was mainly Bacteroidia and Clostridia, and the Ad-NC group had a significantly lower content of Bacteroidia and higher content of Clostridia. KEGG orthology analysis results revealed differences in dehydrogenase, aspartic acid, bile acid, chalcone synthase, acetyltransferase, glutamylcyclotransferase, glycogenin, and 1-phosphatidylinositol-4-phosphate 5-kinase between two groups; enzyme commission (EC) analysis results revealed differences in several dehydrogenase, oxidase, thioxy/reductase between two groups; MetaCyc pathways analysis results revealed differences in isoleucine degradation, oxidation of C1 compounds, tricarboxylic acid (TCA) cycle IV, taurine degradation, and biosynthesis of paromamine, heme, colonic acid building blocks, butanediol, lysine/threonine/methionine, and histidine/purine/pyrimidine between two groups.

CONCLUSION

This study induced a mouse model of GD/GO by Ad-TSHR challenge, and gut microbiota characteristics were identified in the GD/GO mice. The Bacteroidia and Clostridia abundance was changed in the GD/GO mice. These findings may lay a solid experimental foundation for developing personalized treatment regimens for GD patients according to the individual gut microbiota. Given the potential impact of regional differences on intestinal microbiota, this study in China may provide a reference for the global overview of the gut-thyroid axis hypothesis.

Effect of stretch frequency on osteogenesis of periodontium during periodontal ligament distraction

OBJECTIVES

Periodontal ligament distraction (PDLD) can accelerate orthodontic tooth movement (OTM). However, the effect of stretch frequency on osseous formation during PDLD remains unclear. Here, we sought to identify the effect of PDLD frequency on the osteogenic remodelling of the periodontium.

MATERIALS AND METHODS

(i) In vitro, five human periodontal ligament stem cell (PDLSC) cultures were randomized to either static conditions or exposure to a cyclic stretch force involving 12% deformation at frequencies of 0.3, 0.5, 0.7 or 1.0 Hz for 12 h, and the osteogenic differentiation of PDLSCs was assessed using Western blotting. (ii) In vivo, 18 beagle dogs underwent orthodontic distalization of bilateral maxillary first premolars. In the test groups, PDLD was performed at a frequency of two or six times/day, while Ni-Ti coil springs were applied to mimic traditional OTM in the control group. The amount of OTM and histological staining was estimated after force loading for 5, 10 and 15 days.

RESULTS

(i) In vitro, the expression of osteogenic-specific markers (runt-related transcription factor 2 [Runx2], type I collagen [COL-I] and osteocalcin [OCN]) increased with the frequency of tensile force, to a peak at 0.7 Hz. (ii) In vivo, both PDLD groups displayed a greater rate of OTM and a higher bone metabolism than the control group. The expression of COL-I and OCN was significantly reinforced in the six times/day-PDLD group in comparison to the two times/day-PDLD group.

CONCLUSIONS

The cyclic stretch force enhances osteogenesis of the periodontium in a frequency-dependent manner.

[Comparison of three different measurement methods to determine resting energy expenditure in patients with decompensated hepatitis B cirrhosis]

Objective: To compare the differences to determine resting energy expenditure (REE) measured with indirect calorimetry and REE predicted by formula method and body composition analyzer in patients with decompensated hepatitis B cirrhosis, so as to provide theoretical guidance for the implementation of precision nutrition intervention. Methods: Patients with decompensated hepatitis B cirrhosis who were admitted to Henan Provincial People's Hospital from April 2020 to December 2020 were collected. REE was determined by the body composition analyzer and the H-B formula method. Results: were analyzed and compared to REE measured by the metabolic cart. Results A total of 57 cases with liver cirrhosis were included in this study. Among them, 42 were male, aged (47.93 ± 8.62) years, and 15 were female aged (57.20 ± 11.34) years. REE measured value in males was (1 808.14 ± 201.47) kcal/d, compared with the results calculated by the H-B formula method and the measured result of body composition, and the difference was statistically significant (P = 0.002 and 0.003, respectively). REE measured value in females was (1 496.60 ± 131.28) kcal/d, compared with the results calculated by the H-B formula method and the measured result of body composition, and the difference was statistically significant (P = 0.016 and 0.004, respectively). REE measured with the metabolic cart had correlation with age and area of visceral fat in men (P = 0.021) and women (P = 0.037). Conclusion: Metabolic cart use will be more accurate to obtain resting energy expenditure in patients with decompensated hepatitis B cirrhosis. Body composition analyzer and formula method may underestimate REE predictions. Simultaneously, it is suggested that the effect of age on REE in H-B formula should be fully considered for male patients, while the area of visceral fat may have a certain impact on the interpretation of REE in female patients.

Circ_0124055 promotes the progression of thyroid cancer cells through the miR-486-3p/MTA1 axis

BACKGROUND

Thyroid cancer is one of the malignancy cancers. CircRNA, a non-coding RNA, plays an important role in the development of cancer. The relationship and roles of circ_0124055, miR-486-3p and MTA1 in thyroid cancer have not been reported.

METHODS

Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to analyze the RNA levels of circ_0124055, miR-486-3p and MTA1. Western blot was conducted to analyze the protein levels of MTA1, Epithelial cadherin (E-cadherin) and Neuro cadherin (N-cadherin). Subcellular localization assay was used to analyze circ_0124055 location in thyroid cancer cells. Colony formation assay and 5-Ethynyl-2'-deoxyuridine (EdU) assay were carried out to analyze cell proliferation. Cell migration and invasion were analyzed by wound-healing assay and transwell assay. Flow cytometry assay was performed to investigate cell apoptosis. Dual-luciferase reporter assay and RIP assay were employed to analyze the interactions among circ_0124055, miR-486-3p and MTA1. Immunohistochemical (IHC) assay was performed to assess the expression of Ki67, MTA1 and E-cadherin in tumor tissues. Thyroid cancer tumor growth in vivo was evaluated by tumor xenograft mouse model assay.

RESULTS

The expression of circ_0124055 was up-regulated in tumor tissues and cells. Knockdown of circ_0124055 could inhibit thyroid cancer cell proliferation, migration and invasion and promote cell apoptosis, accompanied by the dysregulation of E-cadherin and N-cadherin expression. Circ_0124055 could target miR-486-3p, and miR-486-3p could target MTA1. MiR-486-3p inhibitor could restore the effect of circ_0124055 knockdown in the progression of thyroid cancer. Moreover, MTA1 overexpression weakened the inhibitory effects of miR-486-3p mimics on the progression of thyroid cancer. Further, circ_0124055 could influence tumor growth in vivo.

CONCLUSION

Circ_0124055 promoted the progression of thyroid cancer cells through the miR-486-3p /MTA1 axis.

[Methylophiopogonanone a Inhibits LPS/ATP-Induced Macrophage Pyroptosis via ROS/NLRP3 Pathway]

As a byproduct of mitochondrial respiration or metabolism, reactive oxygen species (ROS) can act as a signaling molecule to activate NLR family pyrin domain containing 3 (NLRP3) inflammasome, thereby triggering immune response. NLRP3 inflammasome acts as a sensor of various danger signals and is central to the control of pyroptosis occurrence. Macrophage pyroptosis is closely related to atherosclerosis, arthritis, pulmonary fibrosis and other inflammatory diseases. Methylophiopogonanone A (MO-A) is a main homoisoflavonoid in Chinese herb Ophiopogonis Radix, which has antioxidant effect. However, it is not clear whether MO-A can alleviate macrophage pyroptosis by inhibiting oxidative stress. Here we have shown that MO-A increases the activities of superoxide dismutase (SOD) and catalase (CAT), inhibits the production of ROS, reduces the activation of NLRP3 inflammasome and the release of lactate dehydrogenase (LDH), and inhibits pyroptosis in macrophages induced by lipopolysaccharides (LPS) and adenosine triphosphate (ATP). These effects can be reversed by the ROS promoter H2O2. Therefore, MO-A can inhibit macrophage pyroptosis through the ROS/NLRP3 pathway and may be considered as a candidate drug for the treatment of inflammatory diseases.

Binding modes of GDP, GTP and GNP to NRAS deciphered by using Gaussian accelerated molecular dynamics simulations

Probing binding modes of GDP, GTP and GNP to NRAS are of significance for understanding the regulation mechanism on the activity of RAS proteins. Four separate Gaussian accelerated molecular dynamics (GaMD) simulations were performed on the apo, GDP-, GTP- and GNP-bound NRAS. Dynamics analyses suggest that binding of three ligands highly affects conformational states of the switch domains from NRAS, which disturbs binding of NRAS to its effectors. The analyses of free energy landscapes (FELs) indicate that binding of GDP, GTP and GNP induces more energetic states of NRAS compared to the apo NRAS but the presence of GNP makes the switch domains more ordered than binding of GDP and GNP. The information of interaction networks of ligands with NRAS reveals that the π-π interaction of residue F28 and the salt bridge interactions of K16 and D119 with ligands stabilize binding of GDP, GTP and GNP to NRAS. Meanwhile magnesium ion plays a bridge role in interactions of ligands with NRAS, which is favourable for associations of GDP, GTP and GNP with NRAS. This work is expected to provide useful information for deeply understanding the function and activity of NRAS.

Constraints on Heavy Decaying Dark Matter from 570 Days of LHAASO Observations

The kilometer square array (KM2A) of the large high altitude air shower observatory (LHAASO) aims at surveying the northern γ-ray sky at energies above 10 TeV with unprecedented sensitivity. γ-ray observations have long been one of the most powerful tools for dark matter searches, as, e.g., high-energy γ rays could be produced by the decays of heavy dark matter particles. In this Letter, we present the first dark matter analysis with LHAASO-KM2A, using the first 340 days of data from 1/2-KM2A and 230 days of data from 3/4-KM2A. Several regions of interest are used to search for a signal and account for the residual cosmic-ray background after γ/hadron separation. We find no excess of dark matter signals, and thus place some of the strongest γ-ray constraints on the lifetime of heavy dark matter particles with mass between 10^{5} and 10^{9}  GeV. Our results with LHAASO are robust, and have important implications for dark matter interpretations of the diffuse astrophysical high-energy neutrino emission.

[Influencing factors for postoperative survival of patients with pneumoconiosis treated by lung transplantation]

Objective: To explore the influencing factors for postoperative survival of patients with pneumoconiosis (silicosis) after lung transplantation in order to improve their clinical outcomes. Methods: In August 2021, retrospective alalysis from December 2015 to July 2021, 29 patients with end-stage pneumoconiosis underwent lung transplantation at Department of Thoracic Surgery, Affiliated Henan Provincial People's Hospital, Zhengzhou University. The survival, postoperative complications, and causes of death were analyzed. Life table and Kaplan-Meier method were used to draw survival curves, the log-rank test was used to compare the influence of each factor on survival rates, and the multivariate Cox proportional hazards regression model was used to evaluate the influence of each factor on survival. Results: All the patients underwent successful lung transplantation, with survival rates of 75% at 6 months, 70% at 1 year, 65% at 2 years, 50% at 3 years and 50% at 5 years. The Kaplan-Meier survival analysis showed that BMI, age and preoperative albumin level were influencing factors for postoperative survival rates (P<0.05) . The multivariate COX regression model showed that BMI≥18.5 kg/m(2) and the albumin level≥35 g/L were the protective factors (P<0.05) . Conclusion: Aging older, preoperative BMI<18.5 kg/m(2) and hypoalbuminemia are independent risk factors for death after lung transplantation. Survival rates are affected by preoperative BMI index, albumin level and age. Early intervention should be made before lung transplantation to promote the BMI index and albumin level to reach the standard.

[Trust in vaccination and its influencing factors among parents of children aged 0-6 years]

Objective: To analyze the trust in vaccination and its influencing factors in parents of children aged 0-6 years. Methods: In June 2021, a cross-sectional survey was conducted to collect the basic information of parents of children aged 0-6 years, including their trust in vaccination and their attitudes towards vaccination. The χ² test was used to compare the difference between different groups, and logistic regression was used to analyze the influencing factors. Results: A total of 10 916 parents of children aged 0-6 years were investigated in this study, and their trust in vaccine was 67.20%, of which safety (55.80%) was the key factor limiting the trust in vaccination. 37.94% (4 142/10 916) of the parents were willing to vaccinate more than two kinds of vaccines at the same time, and 85.07% (9 286/10 916) of the parents feared that abnormal reactions would occur after vaccination. The parents' age, education level and annual family income were the promoting factors of their trust in vaccination (P<0.05). Obtaining vaccine knowledge through vaccination APP or official account (OR=1.330, 95%CI: 1.188-1.489) and popular science leaflets distributed by vaccination clinics (OR=1.120, 95%CI: 1.020-1.228) were the promoting factors of parents' trust in vaccination. Young children and parents, high family income and education level were the promoting factors for parents to be willing to vaccinate at the same time (P<0.05), and young children and parents, low family income and education level were the inducing factors for fear of abnormal reaction after vaccination (P<0.05). Parents of children in the central region had a high acceptance of simultaneous vaccination for children, while parents of children in the western region had a low degree of concern about abnormal reactions after vaccination (P<0.05). Parents of children who read books and got vaccine knowledge online (OR=1.257, 95%CI: 1.153-1.371), urban residents (OR=1.173, 95%CI: 1.062-1.295) and with jobs (OR=1.109, 95%CI: 1.015-1.212) were more willing to vaccinate at the same time. The choice of imported vaccine was a promoting factor for parents to worry about abnormal reactions after vaccination (P<0.05). Conclusion: There is room for parents of children aged 0-6 years to further improve their trust in vaccination. At this stage, it is necessary to innovate the way of health education and health promotion, and pay attention to the publicity of vaccine safety knowledge, so as to improve parents' trust in vaccination.

[A monogenic lupus family caused by homozygous deletions of DNASE1L3 gene and literature review]

Objective: To report the clinical features and genetic variations of monogenic lupus caused by DNASE1L3 deficiency and to introduce preliminary experience on diagnosis and treatment for this disease. Methods: Clinical data of 3 children from the same pedigree were collected who were diagnosed with DNASE1L3 defect-associated monogenic lupus in August 2020 by Department of Pediatrics, Peking Union Medical College Hospital referred from Department of Pediatrics, Boai Hospital of Zhongshan. DNA was extracted from the peripheral blood of the patients and their parients to perform genetic analysis and confirmation. Six interferon-stimulated genes were relatively quantified to examine the activation of the type I interferon signaling. "DNASE1L3" "systemic lupus erythematosus" and "SLE" were searched in PubMed, Wangfang Data, CNKI databases for related reports from database established date to June 2022. Spectrum of genetic variations and clinical phenotypes were analyzed in combination with this pedigree. Results: Case 1, a 14-year-old girl with edema, hematuria, and heavy proteinuria, presented with membranous nephropathy. Case 2, the 12-year-old younger brother of case 1 with hematologic, cardiac, pulmonary, renal involvement, positive antinuclear antibody, positive anti-double-stranded DNA antibody and low complement C3, manifested with systemic lupus erythematosus. Case 3, the 8-year-old younger sister of case 1 with hematologic, cardiac, pulmonary and renal involvement, positive antinuclear antibody, positive anti-double-stranded DNA antibody, and low complement C3 and C4, manifested with systemic lupus erythematosus. Genetic testing revealed that all 3 patients carried homozygous deletions in exons 3 and 4 on DNASE1L3 gene. Interferon scores were elevated in case 1, 2 and their parents but normal in case 3. All 3 patients were diagnosed with monogenic lupus caused by DNASE1L3 defects. Literature searching identified 10 relevant publications in English and 0 publication in Chinese, involving 42 patients from 18 pedigrees (including the 3 cases from this pedigree). Nine variants were found: c.289_290delAC (p.T97Ifs*2), c.643delT (p.W215Gfs*2), c.320+4delAGTA, c.321-1G>A, Ex5 del, c.433G>A, c.581G>A (p.C194Y), c.537G>A (p.W179X), and Ex3-4 del. The hotspot variants were c.643delT (43% (36/84)) and c.289_290delAC (36% (30/84)). Kidney was affected in 31 cases (74%) of the 42 cases. Among the 25 patients, joints were affected in 16 cases (64%), fever were reported in 13 cases (52%) hematologic system was involved 13 cases (52%), rash was present in 10 cases (40%), intestinal tract was involved in 8 cases (32%), lungs were involved in 6 cases (24%), eyes were involved in 4 cases (16%), and the heart was involved in 4 cases (16%). The 2 cardiopulmonary affected patients from literature showed poor prognosis, with 1 died, and 1 right heart failure. Conclusions: The clinical manifestations of monogenic lupus caused by DNASE1L3 defect are highly heterogenous, primarily with renal, blood, joint, intestinal, and cardiopulmonary involvement. There is no correlation between the genotype and the phenotype. DNASE1L3 defects were predominantly mediated by null varations including nonsense, splicing, frameshift and exon deletions. The hotspot variants are c.643delT and c.289_290delAC. DNASE1L3 defects should be cautioned in early-onset lupus-like patients with renal, joint and hematologic involvement. Cardiopulmonary involved patients require close monitoring for poor prognosis. Copy number variations should be carefully analyzed after negative whole exome sequencing.

Study of the Semileptonic Decay Λ_{c}^{+}→Λe^{+}ν_{e}

The study of the Cabibbo-favored semileptonic decay Λ_{c}^{+}→Λe^{+}ν_{e} is reported using a 4.5  fb^{-1} data sample of e^{+}e^{-} annihilations collected at center-of-mass energies ranging from 4.600 GeV to 4.699 GeV with the BESIII detector at the BEPCII collider. The branching fraction of the decay is measured to be B(Λ_{c}^{+}→Λe^{+}ν_{e})=(3.56±0.11_{stat}±0.07_{syst})%, which is the most precise measurement to date. Furthermore, we perform an investigation of the internal dynamics in Λ_{c}^{+}→Λe^{+}ν_{e}. We provide the first direct comparisons of the differential decay rate and form factors with those predicted from lattice quantum chromodynamics (LQCD) calculations. Combining the measured branching fraction with a q^{2}-integrated rate predicted by LQCD, we determine |V_{cs}|=0.936±0.017_{B}±0.024_{LQCD}±0.007_{τ_{Λ_{c}}}.

[Clinical analysis of 49 cases of non-inflammasome related conditions]

Objective: To summarize the clinical characteristics and provide clues for early identification of non-inflammasome related conditions. Methods: The clinical manifestations, laboratory tests, genetic testing and follow-up of 49 children with non-inflammasome related conditions in Peking Union Medical College Hospital from January 2006 to February 2022 were retrospectively analyzed. Results: A total of 49 children, 29 of them were boys and 20 were girls. The age of onset was 0.8 (0.3, 1.6) years, the age at diagnosis was 5.7 (2.8, 8.8) years, and the time from onset to diagnosis was 3.6 (1.9, 6.3) years. Combined with genetic testing results, 49 children with non-inflammasome related conditions were found, including 34 cases (69%) of Blau syndrome, 4 cases (8%) of tumour necrosis factor receptor-associated periodic syndrome, 4 cases (8%) of haploinsufficiency of A20, 2 cases (4%) of Majeed syndrome, 2 cases (4%) of pyogenic sterile arthritis, pyoderma gangrenosum, acne syndrome and 3 cases (6%) of chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature syndrome. There were 22 cases (45%) with a positive family history. The clinical manifestations included 37 cases (76%) cases with rash, 38 cases (78%) with joint involvement, 33 cases (67%) with eye involvement, 17 cases (35%) with recurrent fever. In addition, 11 cases (22%) were complicated with digestive system involvement. Thirty cases (61%) presented as elevated inflammatory indexes (erythrocyte sedimentation rate and (or) C-reactive protein), positive autoantibodies were noticed in 3 cases (6%). The patients were treated with glucocorticoid in 23 cases (47%), immunosuppressive agents in 43 cases (88%) and biologic agents in 37 cases (76%). During the follow-up of 5.8 (2.9, 8.9) years, 3 cases (6%) died. Conclusions: The symptoms of non-inflammasome related conditions include recurrent fever, rash, joint and ocular involvement with increased inflammatory indexes and negative autoantibodies. Up to now, glucocorticoids, immunosuppressants and biologic agents are the most popular medications for the non-inflammasome related conditions.

DNA methylation and waist-to-hip ratio: an epigenome-wide association study in Chinese monozygotic twins

PURPOSE

Epigenetic signatures such as DNA methylation may be associated with specific obesity traits. We performed an epigenome-wide association study (EWAS) by combining with the waist-to-hip ratio (WHR)-discordant monozygotic (MZ) twin design in an attempt to identify genetically independent DNA methylation marks associated with abdominal obesity in Northern Han Chinese and to determine the causation underlying.

METHODS

A total of 60 WHR discordant MZ twin pairs were selected from the Qingdao Twin Registry, China. Generalized estimated equation (GEE) model was used to regress the methylation level of CpG sites on WHR. The Inference about Causation through Examination of FAmiliaL CONfounding (ICE FALCON) was used to assess the temporal relationship between methylation and WHR. Gene expression analysis was conducted to validate the results of differentially methylated analyses.

RESULTS

EWAS identified 92 CpG sites with the level of P < 10^- 4 which were annotated to 32 genes, especially CADPS2, TUSC5, ZCCHC14, CORO7, COL23A1, CACNA1C, CYP26B1, and BCAT1. ICE FALCON showed significant causality between DNA methylation of several genes and WHR (P < 0.05). In region-based analysis, 14 differentially methylated regions (DMRs) located at 15 genes (slk-corrected P < 0.05) were detected. The gene expression analysis identified the significant correlation between expression levels of 5 differentially methylated genes and WHR (P < 0.05).

CONCLUSIONS

Our study identifies the associations between specific epigenetic variations and WHR in Northern Han Chinese. These DNA methylation signatures may have value as diagnostic biomarkers and provide novel insights into the molecular mechanisms of pathogenesis.

Primary pulmonary hyalinising clear cell carcinoma: Two cases and literature review

Hyalinising clear cell carcinoma (HCCC) of the lung is an extremely rare tumour that is just recently recognised as one of the salivary gland-type tumours (SGTT) in the latest WHO classification of thoracic tumours. Eleven cases have been reported in English literature since Joaquín et al. reported the first case. Given the very limited number of cases, the clinical and histological features of pulmonary HCCC are equivocal. Herein, we present two cases of pulmonary HCCC. The patients were a 66-year-old man and a 48-year-old woman. The mass was located on the right main bronchus and right middle lobar bronchus separately. One was 2 cm and the other was 3.3 cm in the greatest dimension. The tumours were comprised of small monomorphic cells with clear or eosinophilic cytoplasm and infiltrated in a hyalinising stroma arranged in nests, cords, sheets and trabeculae. Their morphology resembled their head and neck counterparts. Immunohistochemically, the tumour cells were positive for AE1/AE3, P63, while negative for TTF1, Calponin, S-100, HMB45 and PAX8. Ki-67 labeling ranges from 3% to 10%. Fluorescence in situ hybridisation (FISH) demonstrated EWSR1 rearrangement and Next-generation sequencing (NGS) demonstrated EWSR1- ATF1 (exon 11: exon 3) fusion in case one and EWSR1- ATF1 (exon 2: exon 12) fusion in case two. This is the first time to report the EWSR1-ATF1fusion point other than exon 11: exon 3 in pulmonary HCCC. Case one recurred two years after local resection but didn't metastasise during follow-up 36 months. Case two is alive without disease after lobectomy during follow-up 14 months.

Thrombectomy Using the EmboTrap Clot-Retrieving Device for the Treatment of Acute Ischemic Stroke: A Glimpse of Clinical Evidence

BACKGROUND

The EmboTrap Recanalization Device is a novel stent retriever for thrombectomy in the setting of acute ischemic stroke due to large-vessel occlusion.

PURPOSE

Our aim was to summarize the safety and efficacy of the EmboTrap Recanalization Device in acute ischemic stroke-large-vessel occlusion through a systematic review and meta-analysis.

DATA SOURCES

Medline, EMBASE, the Cochrane Library, Web of Science, and Google Scholar were searched up to April 2022.

STUDY SELECTION

Nine observational studies using the EmboTrap Recanalization Device were selected.

DATA ANALYSIS

We adapted effect size with 95% CIs for dichotomous data. P value <.05 was statistically significant.

DATA SYNTHESIS

The estimated rate of successful recanalization (modified TICI 2b-3) was 90% (95% CI, 86%-95%; I ² = 82.4%); 90-day favorable outcome (mRS 0-2), 53% (95% CI, 42%-63%; I ² = 88.6%); modified first-pass effect, 43% (95% CI, 35%-51%; I ² = 63.7%); and first-pass effect, 36% (95% CI, 29%-46%; I ² = 10.7%). The rate of any intracerebral hemorrhage was 19% (95% CI, 16%-22%; I ² = 0.0%); symptomatic intracerebral hemorrhage, 5% (95% CI, 1%-8%; I ² = 84.6%); and 90-day mortality, 14% (95% CI, 9%-19%; I ² = 79.3%). Subgroup analysis showed higher rates of complete recanalization for EmboTrap II than for the EmboTrap System.

LIMITATIONS

The included studies are single-arm without direct comparison with other stent retrievers. Some of the studies recruited had a small sample size and were limited by the retrospective study design. In addition, the uncertain heterogeneity among studies was high.

CONCLUSIONS

The EmboTrap Recanalization Device is safe and efficient in treating acute ischemic stroke due to large-vessel occlusion.

[Curative effect of complete transperitoneal laparoscopic nephroureterectomy in post kidney transplantation patients with upper tract urothelial carcinoma]

Objective: To investigate the efficacy and safety of complete transabdominal laparoscopic nephroureterectomy in treating primary upper tract urothelial carcinoma (UTUC) for post kidney transplantation patients. Methods: The clinical data of patients with primary renal pelvis and ureter tumors after kidney transplantation in Beijing Chaoyang Hospital from May 2016 to December 2019 were retrospectively analyzed. Seventeen patients (including 9 patients in ipsilateral transplanted kidney group and 8 patients in contralateral transplanted kidney group) underwent traditional retroperitoneoscopic nephroureterectomy (TRNU), and 24 patients (including 14 patients in ipsilateral transplanted kidney group and 10 patients in contralateral transplanted kidney group) underwent complete transperitoneal laparoscopic nephroureterectomy (CTNU). The perioperative clinical indicators of all patients were recorded and analyzed, and the surgical indicators of two techniques were compared. Results: Forty-one patients [16 males and 25 females, with a median age of 57 (53, 70) years old] were finally included. The operation time in the contralateral transplanted kidney group [(95±44) min] from CTNU was significantly decreased compared with that in the ipsilateral group from CTNU [(159±49) min] and the contralateral [(196±20) min] or ipsilateral [(205±21) min] groups from TRNU (all P<0.01). The blood loss volume [(84±39) ml vs (106±44) ml vs (109±20) ml vs (112±21) ml, P=0.271] and postoperative hospital stay [(10.6±2.1) d vs (11.8±1.7) d vs (10.3±1.5) d vs (11.4±1.5) d, P=0.171] were not statistically different among these four groups. During the median follow-up of 24 months, 13 patients developed contralateral recurrence or metastasis, 8 patients developed intravesical recurrence, and 5 patients died of UTUC. Conclusions: Single-position complete transabdominal laparoscopic nephroureterectomy for the treatment of primary renal ureteral tumors after kidney transplantation has the advantage of a short operation time, without increasing intraoperative blood loss or perioperative complications. It is suitable for the treatment of urothelial carcinoma after kidney transplantation, especially for the contralateral side of the transplanted kidney.

[Analysis of clinical features of 380 cases of special portal hypertension-Abernethy malformation]

Objective: To summarize the clinical features of special portal hypertension-Abernethy malformation reported at home and abroad. Methods: The relevant literature on Abernethy malformation published at home and abroad from January 1989 to August 2021 was collected. Patients'clinical features, imaging and laboratory test results, diagnosis, treatment, and prognosis were analyzed. Results: A total of 380 cases were included from 60 and 202 domestic and foreign literatures. Among them, there were 200 cases of type I, with 86 males and 114 females, and the average age was (17.08±19.42) years, while there were 180 cases of type II, with 106 males and 74 females, and the average was (14.85±19.60) years. The most common reason for the first visit of an Abernethy malformation patient's was gastrointestinal system symptoms such as hematemesis and hematochezia caused by portal hypertension (70.56%). Multiple malformations were present in 45.00% of type Ⅰ and 37.80% of type Ⅱ patients. The most prevalent condition was congenital heart disease (62.22%, and 73.53%). Complications related to Abernethy malformation was occurred in 127 and 105 cases with type I and type II, respectively, with liver lesions in 74.02% (94/127) and 39.05% (42/105) and hepatopulmonary syndrome of 33.07% (42/127) and 39.05% (41/105), respectively. The imaging diagnosis of type I and type II Abernethy malformations were mainly based on abdominal computed tomography (59.00%, and 76.11%). Liver pathology was performed in 27.10% of patients. Blood ammonia increased by 89.06% and 87.50%, and AFP increased by 29.63% and 40.00% in laboratory findings. 9.76% (8/82) and 6.92% (9/130) died, while 84.15% (61/82) and 88.46% (115/130) had improved conditions after medical conservative, or surgical treatment. Conclusion: Abernethy malformation is a rare disease in which congenital portal vein development abnormalities lead to significant portal hypertension and portasystemtic shunt. Patients often seek medical treatment for gastrointestinal bleeding and abdominal pain. Type Ⅰ is more common in women, often associated with multiple malformations, and prone to secondary intrahepatic tumors. Liver transplantation is the main treatment method. Type Ⅱ is more prevalent in males, and shunt vessel occlusion is the first treatment choice. Overall, type Ⅱ has a better therapeutic impact than type Ⅰ.

Measurement of the Absolute Branching Fraction and Decay Asymmetry of Λ→nγ

The radiative hyperon decay Λ→nγ is studied using (10087±44)×10^{6}  J/ψ events collected with the BESIII detector operating at BEPCII. The absolute branching fraction of the decay Λ→nγ is determined to be (0.832±0.038_{stat}±0.054_{syst})×10^{-3}, which is a factor of 2.1 lower and 5.6 standard deviations different than the previous measurement. By analyzing the joint angular distribution of the decay products, the first determination of the decay asymmetry α_{γ} is reported with a value of -0.16±0.10_{stat}±0.05_{syst}.

Uncommon Variant of CD4+ T-cell Large Granular Lymphocytic Leukemia

Introduction/Objective

T-cell large granular lymphocytic leukemia (T-LGL) is a T-cell lymphoma with persistently increased large granular lymphocytes in peripheral blood. The majority of T-LGL is associated with CD8+ T-cells. However, the CD4+ variant is uncommonly seen.

Methods/Case Report

The patient is a 49-year-old female with a history of diabetes mellites and anemia who presented with shortness of breath, lower extremities edema, and fatigue. Physical examination showed a significantly distended abdomen. CBC results showed hemoglobin 6.9 g/dL, WBC 18.2 × 109/L with 88% lymphocytes, and PLT 190,000. The peripheral blood smear presented lymphocytosis with LGL cells, microcytic anemia, and increased target cells. Bone marrow biopsy showed lymphoid infiltrate as an intravascular pattern confirmed by immunochemical stains. A complete workup including flow cytometric, cytogenetics, and molecular studies was performed on the bone marrow. The lymphoma phenotype by flow shows positivity for CD2, CD3, CD4, CD5 (bright), CD7 (partial/dim), CD56, CD57 (majority), TCRαβ. T-cell gene rearrangement was detected and was further confirmed by PCR with the detection of clonal TCR beta gene rearrangements on molecular genetics analysis. However, STAT3 was not detected. The patient was diagnosed with CD4+ T-LGL leukemia.

Results (if a Case Study enter NA)

NA.

Conclusion

CD4+CD8- immunophenotype is an uncommon variant of T-LGL, which has a high incidence of activating STAT5B mutation, while CD8+CD4- T-LGLL tends to have STAT3 mutation. Clinically, those two subtypes behave similarly. Flow cytometry is the golden method to confirm the diagnosis. More research is needed to clarify the essence of CD4+ T-LGLL.

Papillary Renal Cell Carcinoma with Massive Hemorrhage: An Autopsy Case Report

Introduction/Objective

Spontaneous renal hemorrhage is a rare complication of various kidney pathologies. It can be due to renal artery aneurysms, arteriovenous malformations, cystic renal diseases, renal calculus, coagulation disorders, as well as neoplastic lesions like angiomyolipoma and renal cell carcinoma (RCC). Individuals present with sudden flank or scapular pain, hypovolemic shock, termed as Wunderlich syndrome (WS). 30-35% cases of WS are from spontaneously ruptured RCC, commonly clear cell variant (70%) followed by papillary (10-15%) and chromophobe variant (4-6%). We present an autopsy case of a papillary variant RCC identified as a small kidney mass with a pathogenetic correlation behind the intractable bleeding.

Methods/Case Report

An 81-year-old Caucasian man with a history of atrial fibrillation, on long-term Xarelto treatment, was found to have a 1.2 cm incidental mass in the right kidney. He started experiencing right-sided scapular pain, then rapidly became hypotensive, drowsy. CT scan revealed a large right-sided perinephric and retroperitoneal hematoma (17.5 x 5.7 x 8.9 cm) extending in the pelvis. Despite receiving blood products, other supportive treatment, and successful angio-embolization, his condition worsened to acute kidney injury, bowel ischemia, and persistent lactic acidosis leading to death. On autopsy, bloody ascites, clots on mesenteric root insertion, and bulging in retroperitoneal spaces were seen. The perinephric spaces had organized clots. The bleeding originated from a 2.0 x 2.0 cm brown mass in the middle pole of the right kidney. There was a slit-like vessel at the interface of the kidney and the mass. Microscopic examination of the mass shows trabecula of abnormal cells with abundant eosinophilic cytoplasm in the hemorrhagic and necrotic background. These cells are positive for PAX8, CK7, CD10, dim positive for CAIX, and negative for CD117, which is consistent with renal cell carcinoma, papillary variant.

Results (if a Case Study enter NA)

NA.

Conclusion

Papillary RCC is much less vascular and less aggressive than clear cell RCC. However, necrosis or bleeding into renal vessels may occur. In this case, blood-leaks and accumulation in enclosed space followed by necrosis, fibrosis, and hyalinization cause neovascularization forming a negative spiral for re-bleeding. Anticoagulants can lead to profuse sustained bleeding from even very small size RCC.

Plasma cell neoplasm with initial presentation as an ovarian mass: a rare case report

Introduction/Objective

Plasmacytoma is a discrete, solitary mass of neoplastic plasma cells. Extramedullary plasmacytoma (EMP) is a rare entity arising in tissues other than bone and it constitutes about 1% of all plasma cell neoplasms. Most cases of reported EMPs are in the upper aerodigestive tract (~80%). We present a very rare case with the initial presentation as an ovarian mass with metastasis into the peritoneal and pleural cavity.

Methods/Case Report

This is a 66-year-old female who presented with generalized abdominal pain, unexpected weight loss, and occasional fever and night sweats. Computed tomography (CT) scan of abdomen and pelvis showed an extensive metastatic disease including bilateral cardiophrenic angle lymphadenopathy, peritoneal spread encasing the bowel loops, bladder, and uterus as well as moderate right pleural effusion. The positron emission tomography (PET)-CT showed an ill-defined soft tissue density in the pelvis with hypermetabolism. The pelvic ultrasound showed a 2.6 x 2.2 x 1.1 cm hypoechoic mass in the left adnexa. The patient's serum cancer antigen (CA-125) was elevated at 123 U/mL and the post-thoracentesis chest x-ray was unremarkable with no acute osseous abnormalities. Other clinical data were not available.

Results (if a Case Study enter NA)

Cytopathologic evaluation of the pleural fluid showed abundant atypical cells with eccentrically located nuclei, scant to moderate cytoplasm with a paranuclear hof, frequent binucleation and mitoses. The cells ranged in size from small to large. Further immunohistochemical (IHC) analysis on the cell block showed that the tumor cells diffusely positive for CD138 and lambda light chain and negative for MOC31, BerEP4, calretinin, D2-40, WT1, HHV8, ALK1, and EBER in situ hybridization (ISH). The biopsy of the left adnexal mass showed a diffuse proliferation of tumor cells with frequent mitotic figures. The IHC analysis on the biopsy specimen showed tumor cells positive for CD79a and CD56 (weak) and negative for CD20 and PAX5. Kappa/lambda ISH analysis confirmed lambda light chain restriction of the tumor cells. These morphological and immunophenotypic features were consistent with plasma cell neoplasm.

Conclusion

The ovary is an unusual location to be involved by plasma cell neoplasm. We use this case to remind the pathologists and clinicians that ovarian plasmacytoma can be the initial presentation of the plasma cell neoplasm, although rare, and to aid the patients to receive an appropriate treatment. A thorough workup is needed to make an accurate diagnosis of this entity.

[Clinicopathological and molecular features of multinodular and vacuolating neuronal tumors of the cerebrum]

Objective: To investigate clinicopathological features of multinodular and vacuolar neurodegenerative tumor (MVNT) of the cerebrum, and to investigate its immunophenotype, molecular characteristics and prognosis. Methods: Four cases were collected at the General Hospital of Southern Theater Command, Guangzhou, China and one case was collected at the First People's Hospital of Huizhou, China from 2013 to 2021. Clinical, histological, immunohistochemical and molecular characteristics of these five cases were analyzed. Follow-up was carried out to evaluate their prognoses. Results: There were four females and one male, with an average age of 42 years (range, 17 to 51 years). Four patients presented with seizures, while one presented with discomfort on the head. Pre-operative imaging demonstrated non-enhancing, T2-hyperintense multinodular lesions in the deep cortex and superficial white matter of the frontal (n=1) or temporal lobes (n=4). Microscopically, the tumor cells were mostly arranged in discrete and coalescent nodules primarily within the deep cortical ribbon and superficial subcortical white matter. The tumors were composed of large cells with ganglionic morphology, vesicular nuclei, prominent nucleoli and amphophilic or lightly basophilic cytoplasm. They exhibited varying degrees of matrix vacuolization. Vacuolated tumor cells did not show overt cellular atypia or any mitotic activities. Immunohistochemically, tumor cells exhibited widespread nuclear staining for the HuC/HuD neuronal antigens, SOX10 and Olig2. Expression of other neuronal markers, including synaptophysin, neurofilament and MAP2, was patchy to absent. The tumor cells were negative for NeuN, GFAP, p53, H3K27M, IDH1 R132H, ATRX, BRG1, INI1 and BRAF V600E. No aberrant molecular changes were identified in case 3 and case 5 using next-generation sequencing (including 131 genes related to diagnosis and prognosis of central nervous system tumors). All patients underwent complete or substantial tumor excision without adjuvant chemoradiotherapy. Post-operative follow-up information over intervals of 6 months to 8 years was available for five patients. All patients were free of recurrence. Conclusions: MVNT is an indolent tumor, mostly affecting adults, which supports classifying MVNT as WHO grade 1. There is no tumor recurrence even in the patients treated with subtotal surgical excision. MVNTs may be considered for observation or non-surgical treatments if they are asymptomatic.

Observation of an Isoscalar Resonance with Exotic J^{PC}=1^{-+} Quantum Numbers in J/ψ→γηη^{'}

Using a sample of (10.09±0.04)×10^{9}  J/ψ events collected with the BESIII detector operating at the BEPCII storage ring, a partial wave analysis of the decay J/ψ→γηη^{'} is performed. The first observation of an isoscalar state with exotic quantum numbers J^{PC}=1^{-+}, denoted as η_{1}(1855), is reported in the process J/ψ→γη_{1}(1855) with η_{1}(1855)→ηη^{'}. Its mass and width are measured to be (1855±9_{-1}^{+6})  MeV/c^{2} and (188±18_{-8}^{+3})  MeV, respectively, where the first uncertainties are statistical and the second are systematic, and its statistical significance is estimated to be larger than 19σ.

Nonisothermal cellular automata simulation of two-dimensional snow crystal growth

Natural snowflakes exhibit remarkable diversity with a fascinating sixfold symmetry and fractal structure. Efforts to discover the snow crystal growth pattern and mechanism behind it have been made in the past 50 years. Among those, cellular automata (CA) have made certain progress. To investigate the influence of latent heat release in snow crystal growth and have a deeper understanding of crystal growth characteristics, an improved CA model combined with vapor diffusion and heat diffusion is proposed to investigate the snowflake growth process in a two-dimensional and nonisothermal field in this paper. Simulation results show that obtained snow crystal growth behavior is consistent with previous experimental observations and satisfies the crystal growth dynamic theory. Latent heat release impacts the small structure of snow crystals, and it could have a more significant influence on snowflake morphology when vapor diffusion is slow and heat diffusion is dominating.

Observation of an a_{0}-like State with Mass of 1.817 GeV in the Study of D_{s}^{+}→K_{S}^{0}K^{+}π^{0} Decays

Using e^{+}e^{-} annihilation data corresponding to an integrated luminosity of 6.32  fb^{-1} collected at center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform the first amplitude analysis of the decay D_{s}^{+}→K_{S}^{0}K^{+}π^{0} and determine the relative branching fractions and phases for intermediate processes. We observe an a_{0}-like state with mass of 1.817 GeV in its decay to K_{S}^{0}K^{+} for the first time. In addition, we measure the ratio {B[D_{s}^{+}→K[over ¯]^{*}(892)^{0}K^{+}]/B[D_{s}^{+}→K[over ¯]^{0}K^{*}(892)^{+}]} to be 2.35_{-0.23stat}^{+0.42}±0.10_{syst}. Finally, we provide a precision measurement of the absolute branching fraction B(D_{s}^{+}→K_{S}^{0}K^{+}π^{0})=(1.46±0.06_{stat}±0.05_{syst})%.

[A case-control study of occupational noise exposure induced high-frequency hearing loss and the risk of hypertension]

Objective: To investigate the relationship between high frequency hearing loss caused by occupational noise and the risk of hypertension. Methods: In March 2020, a case-control study was conducted. All noise exposed workers who participated in occupational health examination in Wuxi City in 2019 were selected as the study subjects (95432 cases in total) . The hypertension group was defined as the case group, and the normotensive group was defined as the control group. According to the hearing threshold, they were divided into the non high frequency hearing loss group (<40 dB) and the high frequency hearing loss group (≥ 40 dB) . Univariate statistical method and binary logistic regression were used to evaluate the relationship between high-frequency hearing loss and hypertension risk. Stratified analysis was used to compare the risk of hypertension among workers with high-frequency hearing loss of different ages and length of service. Results: There were significant differences in gender, age, length of service, enterprise scale, economic type and high-frequency hearing loss between control group and hypertension group (P<0.05) . Binary logistic regression analysis showed that after adjusting for gender, age, length of service, enterprise scale and economic type, the risk of hypertension in the high-frequency hearing loss group was still increased (OR=1.062, 95%CI: 1.007~1.121, P=0.027) . The risk of hypertension in high-frequency hearing loss patients was higher than that in non high-frequency hearing loss patients in 20-39 years old and 40-59 years old age groups (OR=1.536, 95%CI: 1.353~1.743; OR=1.179, 95%CI: 1.111~1.250; P<0.05) . The risk of hypertension in high-frequency hearing loss patients in <5years, 5-9years, 10-14 years, 15-19 years and ≥20 years working age groups were higher than that in non high-frequency hearing loss groups (OR=1.926, 95%CI=1.007-1.121; OR=1.635, 95%CI=1.478-1.810; OR=1.312, 95%CI=1.167-1.474; OR=1.445, 95%CI=1.238-1.686; OR=1.235, 95%CI=1.043-1.463; P<0.05) . Conclusion: There is a certain relationship between high-frequency hearing loss caused by occupational noise and the risk of hypertension, and the risk of hypertension is different among high-frequency hearing loss patients of different ages and working years.

[To ensure universal eye health coverage to accelerate progress towards the achievement of sustainable development goals]

The United Nations signed "Vision for Everyone-Accelerating Action to Achieve the Sustainable Development Goals (A/RES/75/310)" at the 75th UN sessions, committing to great efforts to improve eye health globally and address the increasing impact of vision loss on sustainable development. It is the first agreement designed to tackle preventable sight loss to be adopted at the United Nations and to enshrine eye health as an integral part of universal health coverage. The resolution summarized the lessons learned from previous global eye health practices, set a target of eye care for all by 2030-with countries set to ensure full access to eye care services for their populations, and, to support global efforts, to make eye care part of their nation's journey to achieving the Sustainable Development Goals (SDG). This global initiative will also have a significant impact on eye health in China, and we should implement this United Nations General Assembly Resolution to promote the continued development of eye health in China.

The Biosafety Evaluation for Crustaceans: A Novel Molluscicide PBQ Using against Oncomelania hupensis, the Intermediate Host of Schistosoma japonica

A new formulation (suspension concentrate, SC) of PBQ [1-(4-chlorophenyl)-3-(pyridin-3-yl) urea] was used in water network schistosomiasis-endemic areas to test its molluscicidal efficacy and the acute toxicity to crustaceans. PBQ (20% SC), 26% metaldehyde, and niclosamide suspension concentrate [MNSC (26% SC)] were used both in ditch and field experiments for the molluscicidal efficacy comparison. Acute toxicity tests of two molluscicides were conducted using Neocaridina denticulate and Eriocheir sinensis. Both in the field and ditch experiments, PBQ exhibited comparable molluscicidal efficacy with MNSC. At doses of 0.50 g/m3 and 0.50 g/m2, the snail mortalities were more than 90% three days after PBQ (20% SC) application. Compared with previous tests, PBQ (20% SC) exhibited higher molluscicidal activity than PBQ (25% wettable powder, 25% WP) used in Jiangling and showed similar mollucicidal activity to PBQ (25% WP) used in Dali and Poyang Lake. The 96 h LC50 value of MNSC against Eriocheir sinensis was 283.84 mg a.i./L. At the concentration of PBQ (20% SC) 1000 mg a.i./L, all Eriocheir sinensis were alive. The 96 h LC50 values of PBQ and MNSC against Neocaridina denticulate were 17.67 and 14.05 mg a.i./L, respectively. In conclusion, PBQ (20% SC) had a comparable molluscicidal efficacy with MNSC (26% SC) and PBQ (25% WP). Furthermore, it showed lower toxicity to the crustacean species, better solubility, no floating dust, and convenience for carriage. PBQ (20% SC) was suitable for controlling snails in the water network schistosomiasis-endemic areas.

Search for Unstable Sterile Neutrinos with the IceCube Neutrino Observatory

We present a search for an unstable sterile neutrino by looking for a resonant signal in eight years of atmospheric ν_{μ} data collected from 2011 to 2019 at the IceCube Neutrino Observatory. Both the (stable) three-neutrino and the 3+1 sterile neutrino models are disfavored relative to the unstable sterile neutrino model, though with p values of 2.8% and 0.81%, respectively, we do not observe evidence for 3+1 neutrinos with neutrino decay. The best-fit parameters for the sterile neutrino with decay model from this study are Δm_{41}^{2}=6.7_{-2.5}^{+3.9}  eV^{2}, sin^{2}2θ_{24}=0.33_{-0.17}^{+0.20}, and g^{2}=2.5π±1.5π, where g is the decay-mediating coupling. The preferred regions of the 3+1+decay model from short-baseline oscillation searches are excluded at 90% C.L.

Decoding drug resistant mechanism of V32I, I50V and I84V mutations of HIV-1 protease on amprenavir binding by using molecular dynamics simulations and MM-GBSA calculations

Mutations V32I, I50V and I84V in the HIV-1 protease (PR) induce drug resistance towards drug amprenavir (APV). Multiple short molecular dynamics (MSMD) simulations and molecular mechanics generalized Born surface area (MM-GBSA) method were utilized to investigate drug-resistant mechanism of V32I, I50V and I84V towards APV. Dynamic information arising from MSMD simulations suggest that V32I, I50V and I84V highly affect structural flexibility, motion modes and conformational behaviours of two flaps in the PR. Binding free energies calculated by MM-GBSA method suggest that the decrease in binding enthalpy and the increase in binding entropy induced by mutations V32I, I50V and I84V are responsible for drug resistance of the mutated PRs on APV. The energetic contributions of separate residues on binding of APV to the PR show that V32I, I50V and I84V highly disturb the interactions of two flaps with APV and mostly drive the decrease in binding ability of APV to the PR. Thus, the conformational changes of two flaps in the PR caused by V32I, I50V and I84V play key roles in drug resistance of three mutated PR towards APV. This study can provide useful dynamics information for the design of potent inhibitors relieving drug resistance.

Haze caused by NOx oxidation under restricted residential and industrial activities in a mega city in the south of North China Plain

The formation of secondary aerosol species, including nitrate and sulfate, induces severe haze in the North China Plain. However, despite substantial reductions in anthropogenic pollutants due to severe restriction of residential and industrial activities in 2020 to stop the spread of COVID-19, haze still formed in Zhengzhou. We compared ionic compositions of PM_2.5 during the period of the restriction with that immediately before the restriction and in the comparison period in 2019 to investigate the processes that caused the haze. The average concentration of PM_2.5 was 83.9 μg m^-3 in the restriction period, 241.8 μg m^-3 before the restriction, and 94.0 μg m^-3 in 2019. Nitrate was the largest contributor to the PM_2.5 in all periods, with an average mass fraction of 24%-30%. The average molar concentration of total nitrogen compounds (NO_x + nitrate) was 0.89 μmol m^-3 in the restriction period, which was much lower than that in the non-restriction periods (1.85-2.74 μmol m^-3). In contrast, the concentration of sulfur compounds (SO₂ + sulfate) was 0.34-0.39 μmol m^-3 in all periods. The conversion rate of NO_x to nitrate (NOR) was 0.35 in the restriction period, significantly higher than that before the restriction (0.26) and in 2019 (0.25). NOR was higher with relative humidity in 40-80% in the restriction period than in the other two periods, whereas the conversion rate of SO₂ to sulfate did not, indicating nitrate formation was more efficient during the restriction. When O₃ occupied more than half of the oxidants (O_x = O₃ + NO₂), NOR increased rapidly with the ratio of O₃ to O_x and was much higher in the daytime than nighttime. Therefore, haze in the restriction period was caused by increased NO_x-to-nitrate conversion driven by photochemical reactions.