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.

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})%.

Ir-Catalyzed Chemo-, Regio-, and Enantioselective Allylic Enolization of 6,6-Dimethyl-3-((trimethylsilyl)oxy)cyclohex-2-en-1-one Involving Keto-Enol Isomerization

The utilization of 6,6-dimethyl-3-((trimethylsilyl)oxy)cyclohex-2-en-1-one made from an unsymmetrical 4,4-dimethylcyclohexane-1,3-dione in iridium-catalyzed allylic enolization involving keto-enol isomerization is accomplished under mild conditions. The chemoselectivity, regioselectivity, and enantioselectivity are facilitated by the quaternary carbon and adjusting the reaction conditions. This method provides the substituted 2-(but-3-en-2-yl)-3-hydroxy-6,6-dimethylcyclohex-2-en-1-ones in good to high yields with high level of chemo-, regio-, and enantioselectivities. The chiral carbon-fluorine bond formation is induced by an adjacent chiral carbon center of the allylated 3-hydroxy-6,6-dimethylcyclohex-2-en-1-one, as well.

[Experimental study of the gap ossification in the double-barrel technique in rabbit tibia]

PURPOSE

Double-barrel vascularized fibula graft is one of the most common surgical techniques to augment or maintain the height of the neo-mandible. The purpose of this study was to investigate whether the gap completely disappeared and gap ossification ultimately achieved between the double barrels.

METHODS

Six rabbits were used in the study. Each animal's tibia was vertically osteotomized at its midpoint, folded onto each other and fixed by mini-titanium plate, thus an animal model of "double barrel" was established. Specimens were obtained at 3 months and 6 months postoperatively, then the gap ossification between the double barrels was evaluated by radiography and histomorphology. Measurements of the gap width between the two tibial struts on X-ray films were performed 3 months after the operation at three sites: distal, middle and proximal site. Measurements were compared with those obtained immediately after operation using SPSS 19.0 software package.

RESULTS

Three months after operation, radiography demonstrated that the gap between the double barrels gradually became vague. Histological study showed that irregular new woven bone formed in the gap between the two struts. There was significant difference in mean gap width at the distal and proximal site (P<0.05), but there was no significant difference at the middle site(P=0.552). Radiological and histological study showed cortical bone resorption in the contact area and two thin tubular bones fused into a thicker one 6 months postoperatively.

CONCLUSIONS

The double-barrel tibia fixed with titanium microplate can fuse into a large, unique, continuous bone barrel.

Precise Measurements of Decay Parameters and CP Asymmetry with Entangled Λ-Λ[over ¯] Pairs

Based on 10 billion J/ψ events collected at the BESIII experiment, a search for CP violation in Λ decay is performed in the difference between CP-odd decay parameters α_{-} for Λ→pπ^{-} and α_{+} for Λ[over ¯]→p[over ¯]π^{+} by using the process e^{+}e^{-}→J/ψ→ΛΛ[over ¯]. With a five-dimensional fit to the full angular distributions of the daughter baryon, the most precise values for the decay parameters are determined to be α_{-}=0.7519±0.0036±0.0024 and α_{+}=-0.7559±0.0036±0.0030, respectively. The Λ and Λ[over ¯] averaged value of the decay parameter is extracted to be α_{avg}=0.7542±0.0010±0.0024 with unprecedented accuracy. The CP asymmetry A_{CP}=(α_{-}+α_{+})/(α_{-}-α_{+}) is determined to be -0.0025±0.0046±0.0012, which is one of the most precise measurements in the baryon sector. The reported results for the decay parameter will play an important role in the studies of the polarizations and CP violations for the strange, charmed and beauty baryons.

First Observation of the Direct Production of the χ_{c1} in e^{+}e^{-} Annihilation

We study the direct production of the J^{PC}=1^{++} charmonium state χ_{c1}(1P) in electron-positron annihilation by carrying out an energy scan around the mass of the χ_{c1}(1P). The data were collected with the BESIII detector at the BEPCII collider. An interference pattern between the signal process e^{+}e^{-}→χ_{c1}(1P)→γJ/ψ→γμ^{+}μ^{-} and the background processes e^{+}e^{-}→γ_{ISR}J/ψ→γ_{ISR}μ^{+}μ^{-} and e^{+}e^{-}→γ_{ISR}μ^{+}μ^{-} is observed by combining all the data samples. The χ_{c1}(1P) signal is observed with a significance of 5.1σ. This is the first observation of a C-even state directly produced in e^{+}e^{-} annihilation. The electronic width of the χ_{c1}(1P) resonance is determined to be Γ_{ee}=(0.12_{-0.08}^{+0.13})  eV, which is of the same order of magnitude as theoretical calculations.

Evidence for a Neutral Near-Threshold Structure in the K_{S}^{0} Recoil-Mass Spectra in e^{+}e^{-}→K_{S}^{0}D_{s}^{+}D^{*-} and e^{+}e^{-}→K_{S}^{0}D_{s}^{*+}D^{-}

We study the processes e^{+}e^{-}→K_{S}^{0}D_{s}^{+}D^{*-} and e^{+}e^{-}→K_{S}^{0}D_{s}^{*+}D^{-}, as well as their charge conjugated processes, at five center-of-mass energies between 4.628 and 4.699 GeV, using data samples corresponding to an integrated luminosity of 3.8  fb^{-1} collected by the BESIII detector at the BEPCII storage ring. Based on a partial reconstruction technique, we find evidence of a structure near the thresholds for D_{s}^{+}D^{*-} and D_{s}^{*+}D^{-} production in the K_{S}^{0} recoil-mass spectrum, which we refer to as the Z_{cs}(3985)^{0}. Fitting with a Breit-Wigner line shape, we find the mass of the structure to be (3992.2±1.7±1.6)  MeV/c^{2} and the width to be (7.7_{-3.8}^{+4.1}±4.3)  MeV, where the first uncertainties are statistical and the second are systematic. The significance of the Z_{cs}(3985)^{0} signal is found to be 4.6σ including both the statistical and systematic uncertainty. We report the Born cross section multiplied by the branching fraction at different energy points. The mass of the Z_{cs}(3985)^{0} is close to that of the Z_{cs}(3985)^{+}. Assuming SU(3) symmetry, the cross section of the neutral channel is consistent with that of the charged one. Hence, we conclude that the Z_{cs}(3985)^{0} is the isospin partner of the Z_{cs}(3985)^{+}.

A direct comparison between AML1-ETO and ETO2-GLIS2 leukemia fusion proteins reveals context-dependent binding and regulation of target genes and opposite functions in cell differentiation

The ETO-family transcriptional corepressors, including ETO, ETO2, and MTGR1, are all involved in leukemia-causing chromosomal translocations. In every case, an ETO-family corepressor acquires a DNA-binding domain (DBD) to form a typical transcription factor—the DBD binds to DNA, while the ETO moiety manifests transcriptional activity. A directly comparative study of these “homologous” fusion transcription factors may clarify their similarities and differences in regulating transcription and leukemogenesis. Here, we performed a side-by-side comparison between AML1-ETO and ETO2-GLIS2, the most common fusion proteins in M2-and M7-subtypes of acute myeloid leukemia, respectively, by inducible expression of them in U937 leukemia cells. We found that, although AML1-ETO and ETO2-GLIS2 can use their own DBDs to bind DNA, they share a large proportion of genome-wide binding regions dependent on other cooperative transcription factors, including the ETS-, bZIP- and bHLH-family proteins. AML1-ETO acts as either transcriptional repressor or activator, whereas ETO2-GLIS2 mainly acts as activator. The repressor-versus-activator functions of AML1-ETO might be determined by the abundance of cooperative transcription factors/cofactors on the target genes. Importantly, AML1-ETO and ETO2-GLIS2 differentially regulate key transcription factors in myeloid differentiation including PU.1 and C/EBPβ. Consequently, AML1-ETO inhibits, but ETO2-GLIS2 facilitates, myeloid differentiation of U937 cells. This function of ETO2-GLIS2 is reminiscent of a similar effect of MLL-AF9 as previously reported. Taken together, this directly comparative study between AML1-ETO and ETO2-GLIS2 in the same cellular context provides insights into context-dependent transcription regulatory mechanisms that may underlie how these seemingly “homologous” fusion transcription factors exert distinct functions to drive different subtypes of leukemia.

Observation of Resonance Structures in e^{+}e^{-}→π^{+}π^{-}ψ_{2}(3823) and Mass Measurement of ψ_{2}(3823)

Using a data sample corresponding to an integrated luminosity of 11.3  fb^{-1} collected at center-of-mass energies from 4.23 to 4.70 GeV with the BESIII detector, we measure the product of the e^{+}e^{-}→π^{+}π^{-}ψ_{2}(3823) cross section and the branching fraction B[ψ_{2}(3823)→γχ_{c1}]. For the first time, resonance structure is observed in the cross section line shape of e^{+}e^{-}→π^{+}π^{-}ψ_{2}(3823) with significances exceeding 5σ. A fit to data with two coherent Breit-Wigner resonances modeling the sqrt[s]-dependent cross section yields M(R_{1})=4406.9±17.2±4.5  MeV/c^{2}, Γ(R_{1})=128.1±37.2±2.3  MeV, and M(R_{2})=4647.9±8.6±0.8  MeV/c^{2}, Γ(R_{2})=33.1±18.6±4.1  MeV. Though weakly disfavored by the data, a single resonance with M(R)=4417.5±26.2±3.5  MeV/c^{2}, Γ(R)=245±48±13  MeV is also possible to interpret data. This observation deepens our understanding of the nature of the vector charmoniumlike states. The mass of the ψ_{2}(3823) state is measured as (3823.12±0.43±0.13)  MeV/c^{2}, which is the most precise measurement to date.

[Smith-Kingsmore syndrome caused by MTOR gene variation: 2 cases and literature review]

Objective: To investigate the clinical manifestations and genetic features of 2 children with Smith-Kingsmore syndrome caused by MTOR gene variation and review the literature. Methods: The clinical data of 2 children carrying MTOR gene variant, diagnosed at Xi'an Children's Hospital from April 2018 to April 2021, were retrospectively summarized."MTOR"and"Smith-Kingsmore syndrome"were used as key words to search at China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, PubMed and OMIM up to August 2021. The characteristics of MTOR gene variation and the clinical phenotype of children with Smith-Kingsmore syndrome were summarized. Results: Two children were both females, aged 1.5 years and 2 years respectively, the onset age were both in infancy. They both had developmental delay, megalencephaly and abnormal face. Both whole exome sequencing revealed a de novo heterozygous missense variant in MTOR gene. One case carried c.5395G>A (p.Glu1799Lys) and the other case carried c.7234G>C (p.Asp2412His). There was no literature of MTOR gene variation in Chinese. So far, a total of 45 cases were reported worldwide with detailed clinical information. Eleven variations in MTOR gene were involved, which were all heterozygous missense mutations. Among them, p.Glu1799Lys was the most common sites (28 cases,62%). Another case carried c.7234G>C (p.Asp2412His) was not reported before. Summarizing the 47 cases (including these 2 cases), 46 cases had developmental delay or intellectual disability, 9 cases had developmental regression,42 cases had megalencephaly, 30 cases had facial malformation,16 cases had hypotonia, 17 cases had autism spectrum disorders, 3 cases had hyperactivity, 3 cases had obsessive compulsive disorder, 13 cases had eye diseases, 11 cases had cutaneous vascular malformation, and 9 cases had hypoglycemia. Conclusions: The main clinical features of Smith-Kingsmore syndrome include megalencephaly, developmental delay or intellectual disability, and facial malformation, which can be combined with epilepsy, autism spectrum disorder, hypotonia, hypoglycemia and so on. The variation of MTOR gene is the cause of Smith-Kingsmore syndrome.

[Prognosis of adenoid cystic carcinoma of head and neck and risk factors for lung metastasis]

Objective: To analyze the prognosis and risk factors of lung metastasis of patients with adenoid cystic carcinoma(ACC) of head and neck. Methods: A retrospective study was conducted. The data of 157 patients with ACC of head and neck treated in Beijing Tongren Hospital, Capital Medical University from January 2014 to October 2020 were collected, including 72 males and 85 females, with onset age between 14 and 72 years old. According to whether lung metastasis occurred, the patients were divided into lung metastasis group (88 cases) and non-pulmonary metastasis group (69 cases). Kaplan-Meier method was used to calculate the overall survival rate and progression-free survival rate using SPSS 26.0 software. Log-rank test was used to evaluate statistically relevant clinicopathological factors. Cox proportional risk model was used in multivariate analysis for the factors affecting the lung metastasis-free survival using R Studio 1.2.5042. Results: The 3-year and 5-year overall survival rates were 91.5% and 85.2%, respectively. The 3-year and 5-year progression-free survival rates were 57.7% and 34.3%, respectively. Univariate analysis showed that primary site, histological grade, high-grade transformation, Ki-67, T stage, and lymph node status were the risk factors for lung metastasis (χ²=11.78, 10.41, 4.06, 4.71, 5.37, 16.20, respectively, all P<0.05). Multivariate analysis showed independent risk factors for lung metastasis, including submandibular gland and sublingual gland (HR=3.53, 95%CI: 1.19-10.46, P<0.05), T3-4 stage (HR=3.09, 95%CI: 1.54-6.23, P<0.05), and Grade Ⅱ-Ⅲ grade (HR=2.47, 95%CI: 1.26-4.86,P<0.05). Conclusion: Distant metastasis, mainly pulmonary metastasis, affects the long-term prognosis of patients with ACC significantly. Primary site, T stage and histopathological grade can be used as the predictors for the risk of lung metastasis.

[A statistical measurement of diseases recorded in The Quarterly Reports of the Ophthalmic Hospital at Canton]

The Quarterly Reports of the Ophthalmic Hospital at Canton written by Rev. Peter Parker, an American protestant missionary in China, were serialised in The Chinese Repository from 1836 to 1850. Each report provided the number of patients treated in the corresponding period and described in detail the treatment of diseases which were difficult to deal with. However, due to historical conditions, these reports were inconsistent in terms of the disease classification standards, let alone the statistical deficiencies. This paper aims to regroup the diseases recorded in the 15 reports according to the classification from the eleventh to fifteenth report and recount the patient number of each disease systematically in different periods, with reliable historical data to support such relevant studies as the history of the Ophthalmic Hospital at Canton and the introduction of Western Medicine into China and the development of International Classification of Diseases.

Features and clinical significance of tertiary lymphoid structure in cutaneous squamous cell carcinoma

BACKGROUND

Tertiary lymphoid structure (TLS) plays an important role in anti-tumor immunity, largely reflecting the prognosis. However, its clinical implication in cutaneous squamous cell carcinoma (cSCC) remains unknown.

OBJECTIVES

To explore the features of TLS in cSCC and its association with clinicopathological characteristics.

METHODS

Two independent RNA-seq data of cSCC were used to investigate the tumor immune microenvironment, as well as TLS-related chemokines and cytokines. The density and location of TLSs were assessed in a total of 82 cSCC patients, and the clinicopathologic association was examined.

RESULTS

Bioinformatics analysis showed that a large amount of immune cell infiltration and significant up-regulation of TLS-related chemokines were observed in cSCC. Histologically, TLSs appeared as highly organized structures in 72 (87.8%) cases with different levels of density and maturation, among which 14 cases were in low-density group and 58 cases were in high-density group. Clinically, the presence of TLS was prominently associated with better degree of histopathological grades and higher level of sun exposure. Furthermore, the presence of intratumoral TLS was associated with lower lymphovascular invasion.

CONCLUSIONS

TLS is highly organized in cSCC, and the presence of TLS is a positive prognostic factor for cSCC, which will provide a theoretical basis for the future diagnostic and therapeutic value in cSCC.

Observation of a State X(2600) in the π^{+}π^{-}η' System in the Process J/ψ→γπ^{+}π^{-}η'

Based on (10087±44)×10^{6}  J/ψ events collected with the BESIII detector, the process J/ψ→γπ^{+}π^{-}η^{'} is studied using two largest decay channels of the η^{'} meson, η^{'}→γπ^{+}π^{-} and η^{'}→ηπ^{+}π^{-}, η→γγ. A new resonance, which we denote as the X(2600), is observed with a statistical significance larger than 20σ in the π^{+}π^{-}η^{'} invariant mass spectrum, and it has a connection to a structure around 1.5  GeV/c^{2} in the π^{+}π^{-} invariant mass spectrum. A simultaneous fit on the π^{+}π^{-}η^{'} and π^{+}π^{-} invariant mass spectra with the two η^{'} decay modes indicates that the mass and width of the X(2600) state are 2618.3±2.0_{-1.4}^{+16.3}  MeV/c^{2} and 195±5_{-17}^{+26}  MeV, where the first uncertainties are statistical, and the second systematic.

Observation of J/ψ Electromagnetic Dalitz Decays to X(1835), X(2120), and X(2370)

Using a sample of about 10^{10}  J/ψ events collected at a center-of-mass energy sqrt[s]=3.097  GeV with the BESIII detector, the electromagnetic Dalitz decays J/ψ→e^{+}e^{-}π^{+}π^{-}η^{'}, with η^{'}→γπ^{+}π^{-} and η^{'}→π^{+}π^{-}η, have been studied. The decay J/ψ→e^{+}e^{-}X(1835) is observed with a significance of 15σ, and also an e^{+}e^{-} invariant-mass dependent transition form factor of J/ψ→e^{+}e^{-}X(1835) is presented for the first time. The intermediate states X(2120) and X(2370) are also observed in the π^{+}π^{-}η^{'} invariant-mass spectrum with significances of 5.3σ and 7.3σ. The corresponding product branching fractions for J/ψ→e^{+}e^{-}X, X→π^{+}π^{-}η^{'} [X=X(1835), X(2120), and X(2370)] are reported.

[Clinical characteristics and vaccination status of SARS-CoV-2 Omicron variant infected children]

Objective: To investigate the clinical characteristics and vaccination status of SARS-CoV-2 Omicron variant infected children. Methods: A total of 105 children infected with Omicron variant admitted to Tianjin Haihe Hospital (designated referral hospital for SARS-CoV-2 infection in Tianjin) from January 8, 2022 to February 3 were included for a retrospective study. The cases were divided into pneumonia group and non-pneumonia group according to chest imaging. Based on the doses of inactivated SARS-CoV-2 vaccine, the children who completed SARS-CoV-2 antibody test within 3 days after hospitalization were divided into 2 dose group and<2 dose group.Rank sum test and Chi-square test were used for the comparison between the groups. Results: The age of these 105 children was 10 (8, 11) years on admission, 53 children were males and 52 were females. Eighty-seven cases (82.9%) had mild symptoms, 13 cases (12.4%) had common symptoms and 5 cases (4.8%) were asymptomatic. Ninety-one cases (86.7%) completed 2 doses vaccination. The clinical symptoms were characterized by cough (74 cases, 70.5%), fever (58 cases, 55.2%), sore or dry throat (34 cases, 32.4%), nasal congestion (28 cases, 26.7%), rhinorrhea (23 cases, 21.9%). None of the children received antivirals, steroids, immunosuppressant or oxygen therapy. Seventy-six cases(72.4%) received traditional Chinese medicine treatment. The pneumonia group had a higher rate of positive SARS-CoV-2 IgG within 1 day after admission (13/13 vs. 87.0% (80/92), χ2=42.81, P<0.001) than the non-pneumonia group. Among the 62 children who had serial SARS-CoV-2 antibody tests within 3 days after hospitalization, Compared to the<2 dose group, the 2 dose group had a higher rate of nucleic acid conversion within 16 days after onset and a higher rate of positive SARS-CoV-2 IgG 1 day after admission and 3 days after hospitalization (96.4% (54/56) vs. 4/6, 100.0% (56/56) vs. 2/6, 100.0% (56/56) vs. 3/6, all P<0.05). Conclusions: Most children infected with Omicron variant have mild symptoms, mainly respiratory infection symptoms. The proportion of SARS-CoV-2 antibody IgG positive in children who have received 2 doses of inactivated SARS-CoV-2 vaccines is higher,and the time of whose nucleic acid conversion may be shortened.

[Clinical analysis of 5 cases of systemic juvenile idiopathic arthritis with coronary artery dilatation]

Objective: To investigate the clinical characteristics of systemic juvenile idiopathic arthritis combined with coronary artery dilatation. Methods: A retrospective analysis was performed on the clinical data, including clinical manifestations, blood routine, inflammatory factors, echocardiography, vascular ultrasound and CT angiography, treatment and outcomes, etc, of 5 cases with systemic juvenile idiopathic arthritis combined with coronary artery dilation admitted to Department of Rheumatology in the affiliated Children's Hospital of Capital Institute of Pediatrics from May 2019 to June 2021. Results: There were 2 males and 3 females among 5 cases. The onset age ranged from 7 months to 4 years 7 months.The diagnostic time ranged from 1.5 months to 3.0 months.Four cases were diagnosed as atypical Kawasaki disease. Three cases showed unilateral coronary artery dilation.Two cases showed bilateral coronary artery dilation.Four cases developed multiple organ injuries.Three cases developed macrophage activation syndrome.Three cases developed lung injury.Two cases developed pericardial effusion.One case developed pulmonary hypertension.As for treatment, 3 cases treated with methylprednisolone pulse therapy and methotrexate combined with cyclosporine, improved after the final application of biological agents, and have stopped prednisone. The other 2 cases were treated with adequate oral prednisone and gradually reduced, and methotrexate was added at the same time, 1 case relapsed in the process of reduction. No other vascular involvement was found in 5 cases. Coronary artery dilation recovered completely after 1 to 3 months of treatment. Conclusions: Systemic juvenile idiopathic arthritis combined with coronary artery dilatation has the clinical characteristics of small onset age, long diagnostic time, prone to multiple organ injuries. Corticosteroids and conventional immunosuppressive agents are not sensitive, and biological agents should be used as soon as possible.The prognosis of coronary artery dilation is good after timely treatment.

Steriod for Autoimmune pancreatitis complicating by gastric varices: A case report

BACKGROUND

Both autoimmune pancreatitis (AIP) and gastric varices are related to various diseases. However, AIP complicated by gastric varices is extremely rare, and has only been reported in a few studies. Here, we report a case of AIP complicated by gastric varices in a female Chinese patient.

CASE SUMMARY

A 59-year-old Chinese woman was admitted to our hospital with mild abdominal pain. Computed tomography and magnetic resonance cholangiopancreatography revealed a diffusely enlarged pancreas, an obstructed splenic vein and slight splenomegaly. Esophagogastroduodenoscopy showed gastric varices in the partial gastric fundus and the red-color sign was positive. Blood chemistry showed that IgG4 was notablely elevated. The patient was diagnosed with AIP complicated by gastric varices. Steroid therapy was administered to this patient with the risk of gastrointestinal bleeding. After one year of therapy, the pancreas, spleen and splenic vein recovered to the normal states, and the gastric varices had disappeared.

CONCLUSION

We present this case together with evidence from the literature to demonstrate the effectiveness of steroid therapy in the treatment of AIP complicated by gastric varices.

[Epidemiological characteristics of imported COVID-19 cases in Beijing]

Objective: To analyze the epidemiological characteristics of imported COVID-19 cases and the effect of vaccination on virus load and disease severity of the cases in Beijing. Methods: The data of the imported COVID-19 cases in Beijing were collected from the National Notifiable Infectious Disease Reporting System of China Information for Disease Control and Prevention and Epidemiology investigation. The data were processed and analyzed by Excel 2010 and SPSS 22.0. Results: From June 1 to September 30, 2021, a total of 171 imported COVID-19 cases were reported in Beijing, of which 66.67% (114/171) were asymptomatic. The cases were mainly from the Philippines, the United Arab Emirates, the United Kingdom and the Russian Federation, accounting for 67.84% (116/171). The male to female ratio of the cases was 2∶1 (114∶57). The median age M (Q₁, Q₃) of the cases was 28 (23, 36) years. The cases of Chinese accounted for 80.12% (137/171). The sequencing of the whole genome of the virus in 47 imported COVID-19 cases showed that the proportion of Delta variant was 76.60% (36/47). The COVID-19 vaccination coverage rate in the cases was 60.82% (104/171), but the full vaccination coverage rate was 53.80% (92/171). In the imported COVID-19 cases, 13.53% (23/170) were screened to be SARS-CoV-2 nucleic acid positive on the day when they arrived in Beijing, and all the cases were positive for 2019-nCoV nucleic acid within 28 days. The severity of the disease was higher in the unvaccinated group than in the partially vaccinated group and fully vaccinated group (P<0.001). In the unvaccinated group, there were 1 severe case and 1 critical case. The median Ct values M (Q₁, Q₃) of N gene and ORFlab gene in unvaccinated group were 32.51 (23.23, 36.06) and 32.78 (24.00, 36.38), respectively. There was no significant difference in the median of double-gene Ct value between the partially vaccinated group and the fully vaccinated group. Conclusions: During the study period, most of the imported COVID-19 cases in Beijing were asymptomatic. No matter vaccinated or not, the viral loads in the COVID-19 cases were similar, but the vaccination could reduce the severity of the disease.

Observation of the Singly Cabibbo Suppressed Decay Λ_{c}^{+}→nπ^{+}

The singly Cabibbo-suppressed decay Λ_{c}^{+}→nπ^{+} is observed for the first time with a statistical significance of 7.3σ by using 3.9  fb^{-1} of e^{+}e^{-} collision data collected at center-of-mass energies between 4.612 and 4.699 GeV with the BESIII detector at BEPCII. The branching fraction of Λ_{c}^{+}→nπ^{+} is measured to be (6.6±1.2_{stat}±0.4_{syst})×10^{-4}. By taking the upper limit of branching fractions of Λ_{c}^{+}→pπ^{0} from the Belle experiment, the ratio of branching fractions between Λ_{c}^{+}→nπ^{+} and Λ_{c}^{+}→pπ^{0} is calculated to be larger than 7.2 at the 90% confidence level, which disagrees with most predictions of the available phenomenological models. In addition, the branching fractions of the Cabibbo-favored decays Λ_{c}^{+}→Λπ^{+} and Λ_{c}^{+}→Σ^{0}π^{+} are measured to be (1.31±0.08_{stat}±0.05_{syst})×10^{-2} and (1.22±0.08_{stat}±0.07_{syst})×10^{-2}, respectively, which are consistent with previous results.

Measurement of Two-Particle Correlations of Hadrons in e^{+}e^{-} Collisions at Belle

The measurement of two-particle angular correlation functions in high-multiplicity e^{+}e^{-} collisions at sqrt[s]=10.52  GeV is reported. In this study, the 89.5  fb^{-1} of hadronic e^{+}e^{-} annihilation data collected by the Belle detector at KEKB are used. Two-particle angular correlation functions are measured in the full relative azimuthal angle (Δϕ) and three units of pseudorapidity (Δη), defined by either the electron beam axis or the event-shape thrust axis, and are studied as a function of charged-particle multiplicity. The measurement in the thrust axis analysis, with mostly outgoing quark pairs determining the reference axis, is sensitive to the region of additional soft gluon emissions. No significant anisotropic collective behavior is observed with either coordinate analyses. Near-side jet correlations appear to be absent in the thrust axis analysis. The measurements are compared to predictions from various event generators and are expected to provide new constraints to the phenomenological models in the low-energy regime.

[Identification and analysis of 2 Corynebacterium diphtheria strains in Guangdong Province]

Objective: To identify and analyze two strains of C. diphtheriae in Guangdong Province by combining whole genome sequencing with traditional detection methods. Methods: The C. diphtheriae was isolated from Guangzhou in 2010 and Zhuhai in 2020 respectively. Isolates were identified by API Coryne strips and MALDI-TOF-MS. Genomic DNA was sequenced by using Illumina. The assembly was performed for each strain using CLC software. J Species WS online tool was used for average nucleoside homology identification, then narKGHIJ and tox gene were detected by NCBI online analysis tool BLSATN. MEGA-X was used to build a wgSNP phylogenetic tree. Results: GD-Guangzhou-2010 was Belfanti and GD-Zuhai-2020 was Gravis. ANIb between GD-Guangzhou-2010 and C. belfantii was 99.61%. ANI between GD-Zhuhai-2020 and C. diphtheriae was 97.64%. BLASTN results showed that the nitrate reduction gene narKGHIJ and tox gene of GD-Guangzhou-2010 was negative, while GD-Zhuhai-2020 nitrate reduction gene narKGHIJ was positive. There were two obvious clades in wgSNP phylogenetic tree. The first clades included all Mitis and Gravis types strains as well as GD-Zhuhai-2020. The second clades contained all isolates of C.belfantii, C.diphtheriae subsp. lausannense and GD-guangzhou-2010. Conclusion: Two non-toxic C. diphtheriae strains are successfully isolated and identified. The phylogenetic tree suggests that GD-Guangzhou-2010 and GD-Zhuhai-2020 are located in two different evolutionary branches.

[Evaluation of safety and immunogenicity of hepatitis E vaccine in maintenance hemodialysis patients]

Objective: To evaluate the safety and immunogenicity of hepatitis E vaccine(HEV)in Maintenance hemodialysis(MHD)patients. Methods: Based on an open-labeled controlled trial, from May 2016 to March 2018, 35 eligible MHD patients were recruited in the Hemodialysis Center of Zhongshan Hospital Affiliated to Xiamen University as the experimental group, and 70 MHD patients with matched age, gender and underlying diseases as the control group. The experimental group received HEV at 0, 1 and 6 months according to the standard vaccination procedures, while the control group received routine diagnosis and treatment without vaccine and placebo injection to observe the safety and immunogenicity of the vaccine. The safety of vaccine in MHD population was evaluated by the incidence of adverse reactions/events in the experimental and control groups. The immunogenicity of HEV in MHD patients was evaluated by comparing the data from the phase Ⅲ clinical trial. Results: The overall incidence of adverse reactions/events was 17.1% (18/105), and there were no grade 3-4 adverse reactions/events related to vaccination. In the experimental group, the incidence of local adverse reactions/events was 20.0% (7/35), and the incidence of systemic adverse reactions/events was 17.1% (6/35).There was no significant difference in the incidence of systemic adverse reactions/events between the experimental group and the control group (P>0.05). There were 23 patients receiving 3 doses with the standard schedule. The positive rate of HEV-IgG antibody was 100% and the GMC was 14.47(95%CI:13.14-15.80) WU/ml, which showed no significant difference compared with the 46 patients in Phase Ⅲ clinical trial (t=-1.04, P>0.05). Conclusion: Recombinant HEV has good safety and immunogenicity in MHD patients.

Spectrum Reconstruction with Filter-Free Photodetectors Based on Graded-Band-Gap Perovskite Quantum Dot Heterojunctions

Spectrum reconstruction with filter-free microspectrometers has attracted much attention owing to their promising potential in in situ analysis systems, on-chip spectroscopy characterizations, hyperspectral imaging, etc. Further efforts in this field can be devoted to improving the performance of microspectrometers by employing high-performance photosensitive materials and optimizing the reconstruction algorithms. In this work, we demonstrate spectrum reconstruction with a set of photodetectors based on graded-band-gap perovskite quantum dot (PQD) heterojunctions using both calculation and machine learning algorithms. The photodetectors exhibit good photosensitivities with nonlinear current-voltage curves, and the devices with different PQD band gaps show various spectral responsivities with different cutoff wavelength edges covering the entire visible range. Reconstruction performances of monochromatic spectra with the set of PQD photodetectors using two different algorithms are compared, and the machine learning method achieves relatively better accuracy. Moreover, the nonlinear current-voltage variation of the photodetectors can provide increased data diversity without redundancy, thus further improving the accuracy of the reconstructed spectra for the machine learning algorithm. A spectral resolution of 10 nm and reconstruction of multipeak spectra are also demonstrated with the filter-free photodetectors. Therefore, this study provides PQD photodetectors with the corresponding optimized algorithms for emerging flexible microspectrometer systems.