A binary pulsar in a 53-minute orbit.

Spider pulsars are neutron stars that have a companion star in a close orbit. The companion star sheds material to the neutron star, spinning it up to millisecond rotation periods, while the orbit shortens to hours. The companion is eventually ablated and destroyed by the pulsar wind and radiation1,2. Spider pulsars are key for studying the evolutionary link between accreting X-ray pulsars and isolated millisecond pulsars, pulsar irradiation effects and the birth of massive neutron stars3-6. Black widow pulsars in extremely compact orbits (as short as 62 minutes7) have companions with masses much smaller than 0.1 M⊙. They may have evolved from redback pulsars with companion masses of about 0.1-0.4 M⊙ and orbital periods of less than 1 day8. If this is true, then there should be a population of millisecond pulsars with moderate-mass companions and very short orbital periods9, but, hitherto, no such system was known. Here we report radio observations of the binary millisecond pulsar PSR J1953+1844 (M71E) that show it to have an orbital period of 53.3 minutes and a companion with a mass of around 0.07 M⊙. It is a faint X-ray source and located 2.5 arcminutes from the centre of the globular cluster M71.

A repeating fast radio burst associated with a persistent radio source.

The dispersive sweep of fast radio bursts (FRBs) has been used to probe the ionized baryon content of the intergalactic medium1, which is assumed to dominate the total extragalactic dispersion. Although the host-galaxy contributions to the dispersion measure appear to be small for most FRBs2, in at least one case there is evidence for an extreme magneto-ionic local environment3,4 and a compact persistent radio source5. Here we report the detection and localization of the repeating FRB 20190520B, which is co-located with a compact, persistent radio source and associated with a dwarf host galaxy of high specific-star-formation rate at a redshift of 0.241 ± 0.001. The estimated host-galaxy dispersion measure of approximately [Formula: see text] parsecs per cubic centimetre, which is nearly an order of magnitude higher than the average of FRB host galaxies2,6, far exceeds the dispersion-measure contribution of the intergalactic medium. Caution is thus warranted in inferring redshifts for FRBs without accurate host-galaxy identifications.

Broadening of the Divertor Heat Flux Profile in High Confinement Tokamak Fusion Plasmas with Edge Pedestals Limited by Turbulence in DIII-D.

Multimachine empirical scaling predicts an extremely narrow heat exhaust layer in future high magnetic field tokamaks, producing high power densities that require mitigation. In the experiments presented, the width of this exhaust layer is nearly doubled using actuators to increase turbulent transport in the plasma edge. This is achieved in low collisionality, high confinement edge pedestals with their gradients limited by turbulent transport instead of large-scale, coherent instabilities. The exhaust heat flux profile width and divertor leg diffusive spreading both double as a high frequency band of turbulent fluctuations propagating in the electron diamagnetic direction doubles in amplitude. The results are quantitatively reproduced in electromagnetic XGC particle-in-cell simulations which show the heat flux carried by electrons emerges to broaden the heat flux profile, directly supported by Langmuir probe measurements.

Preparation, X-ray Characterization, and Reactivity of the Rod-like and Angular Germanium- and Titanium(IV)-Capped Iron(II) Bis-Clathrochelates and Their Mono- and Bis-Capped (Semi)clathrochelate Precursors.

Transmetalation of the bis{triethylantimony(V)}-capped iron(II) tris-α-dioximate with n-butylboronic acid afforded the mixed antimony, boron cross-linked clathrochelate with single reactive antimony(V)-based apical fragment. This macrobicyclic precursor easily underwent the transmetalation reactions with germanium and titanium(IV) alkoxides to give the rod-like and angular FeII2MIV-trinuclear bis-clathrochelates. Those of the aforementioned diantimony(V)-capped complex with 3- and 4-carboxyphenylboronic acids afforded the monoboron-capped iron(II) semiclathrochelates, undergoing a double-cyclization (macrobicyclization) with germanium- and titanium(IV)-based capping agents. The reactions in the low-temperature range unexpectedly gave the stable 2:1 associates, formed by the bridging of two carboxyl-terminated macrobicyclic molecules of the mixed carboxylboron, triethylantimony-capped iron(II) clathrochelate with a triethylantimony(V)-based linker fragment. The obtained complexes were characterized using elemental analysis, MALDI-TOF, 1H and 13C{1H} NMR and UV-vis spectra, and single-crystal XRD experiments. The encapsulated iron(II) ion in their 3D-molecules is situated almost in the center of its FeN6-coordination polyhedron possessing a truncated trigonal-pyramidal geometry. Fe-N distances fall in the range 1.887(7)-1.945(4) Å characteristic of the low-spin iron(II) complexes. The cross-linking titanium and germanium(IV) ions in the corresponding bis-clathrochelate molecules form the octahedral MIVO6-coordination polyhedra, the MIV-O distances of which vary from 1.946(2) to 1.964(2) Å and from 1.879(7) to 1.907(6) Å, respectively.

Vegetation-fire feedbacks increase subtropical wildfire risk in scrubland and reduce it in forests.

Climate dictates wildfire activity around the world. But East and Southeast Asia are an apparent exception as fire-activity variation there is unrelated to climatic variables. In subtropical China, fire activity decreased by 80% between 2003 and 2020 amid increased fire risks globally. Here, we assessed the fire regime, vegetation structure, fuel flammability and their interactions across subtropical Hubei, China. We show that tree basal area (TBA) and fuel flammability explained 60% of fire-frequency variance. Fire frequency and fuel flammability, in turn, explained 90% of TBA variance. These results reveal a novel system of scrubland-forest stabilized by vegetation-fire feedbacks. Frequent fires promote the persistence of derelict scrubland through positive vegetation-fire feedbacks; in forest, vegetation-fire feedbacks are negative and suppress fire. Thus, we attribute the decrease in wildfire activity to reforestation programs that concurrently increase forest coverage and foster negative vegetation-fire feedbacks that suppress wildfire.

[Impact of autologous hematopoietic stem cell transplantation on the efficacy of CAR-T treatment of relapsed/refractory multiple myeloma].

Objective: To evaluate the effect of autologous hematopoietic stem cell transplantation (ASCT) on the treatment of relapsed/refractory multiple myeloma (RRMM) with chimeric antigen receptor T cell (CAR-T) therapy. Methods: A retrospective cohort study. The clinical data of 168 patients with RRMM who underwent CAR-T therapy at the Department of Hematology, Xuzhou Medical University Hospital from 3 January 2020 to 13 September 2022 were analyzed. Patients were classified into a transplantation group (TG; n=47) and non-transplantation group (NTG; n=121) based on whether or not they had undergone ASCT previously. The objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and the levels of CD3, CD4, CD8, CD19, CD56 and natural killer (NK) cells before CAR-T infusion were analyzed by χ2 test, Kaplan-Meier method and independent sample t-test. Results: Among 168 patients with RRMM, 98 (58.3%) were male. The median age of onset was 57 (range 30-70) years. After CAR-T therapy, the ORR of patients was 89.3% (92/103) in the NTG and 72.9% (27/73) in the TG. The ORR of the NTG was better than that of the TG (χ2=5.71, P=0.017). After 1 year of CAR-T therapy, the ORR of the NTG was 78.1% (75/96), and that of the TG was 59.4% (19/32). The ORR of the NTG was better than that of the TG (χ2=4.32, P=0.038). The median OS and PFS in the NTG were significantly longer than those in the TG (OS, 30 vs. 20 months; PFS, 26 vs. 12 months; both P<0.05). The CD4 level before CAR-T infusion in the TG was significantly lower than that in the NTG (25.65±13.56 vs. 32.64±17.21; t=-2.15, P=0.034), and there were no significant differences in the counts of CD3, CD8, CD19, CD56, and NK cells between the TG and NTG (all P>0.05). Conclusion: Among patients suffering from RRMM who received CAR-T therapy, patients who did not receive ASCT had significantly better outcomes than those who had received ASCT previously, which may have been related to the CD4 level before receiving CAR-T therapy.

[The occurrence of cytokine release syndrome and its impact on the prognosis of patients with relapsed and refractory multiple myeloma following chimeric antigen receptor T-cell therapy].

Objective: To analyze the incidence of cytokine release syndrome (CRS) and its impact on the prognosis of patients with relapsed and refractory multiple myeloma (RRMM) following treatment with chimeric antigen receptor T-cell (CAR-T) therapy. Methods: A retrospective collection was conducted of the clinical data of 91 patients with RRMM who underwent CAR-T therapy at the Affiliated Hospital of Xuzhou Medical University from January 2020 to October 2022. Before CAR-T cell infusion, the patient underwent pretreatment with the fludarabine plus cyclophosphamide (FC) regimen. On day 0 (d0), the patient received a dose of 1×106 cells/kg of CAR-T. The occurrence of CRS was recorded post-treatment and graded accordingly, with grades 1 to 2 indicating mild CRS and grade≥3 indicating severe CRS. The follow-up cut-off date was February 14, 2023, with a median follow-up time [M (Q1, Q3)] of 14.1 (3.1, 37.7) months. Kaplan-Meier survival curve analysis assessed the progression-free survival (PFS) and overall survival (OS) of Grade 1 and Grade 2 CRS patients. Furthermore, univariate logistic regression analysis was conducted to identify factors associated with the development of severe CRS. Results: In a cohort of 91 patients diagnosed with RRMM, there were 51 male and 40 female individuals, with a median age [M (Q1,Q3)] of 57 (31, 73) years. All 91 cases (100%) experienced CRS, with 82 cases (90%) classified as mild (grades 1-2) CRS and 9 cases (10%) classified as severe (grades 3-5) CRS. In a study involving 9 patients with severe CRS, 8 cases resulted in mortality. The Kaplan-Meier survival curve analysis revealed that among grade 1 CRS patients, neither the median PFS nor the median OS was achieved. For grade 2 CRS patients, the median PFS was 12 months (95%CI: 4-not achieved), and the median OS was 21 months (95%CI: 4-not achieved). The progression-free survival and overall survival rates of grade 2 CRS patients were both lower than those of grade 1 CRS patients (both P<0.05). Single-factor logistic regression analysis revealed that a high tumor burden (OR=1.025, 95%CI: 1.002-1.049, P=0.031), a prolonged duration of CRS onset (OR=0.809, 95%CI: 0.646-0.971, P=0.037) and persistence (OR=1.758, 95%CI: 1.349-2.481, P=0.001) were identified as significant factors associated with severe CRS in patients with RRMM. Conclusions: Patients with RRMM who undergoes CAR-T therapy have a high incidence of CRS, with a higher mortality rate among those experiencing severe CRS. Furthermore, patients with grade 2 CRS exhibit lower rates of progression-free survival and overall survival compared to those with grade 1 CRS. Factors associated with the development of severe CRS in RRMM patients include high tumor burden and prolonged duration and onset of CRS.

[Multivariate analysis of psychological health among hospital infection prevention and control practitioners in Tianjin].

Objective: To understand the occupational stress and mental health status of hospital infection prevention and control practitioner (HIPCPs) in medical institutions, and analyze their main influencing factors. Methods: In November 2021, 550 nosocomial infection managers in Tianjin were randomly selected to conduct a questionnaire survey using the Concise Occupational Stress Questionnaire, Depression Screening Scale (PHQ-9) and Self-Rating Anxiety Scale (SAS). 497 valid questionnaires were obtained, and the total recovery efficiency was 90.36%. Single factor analysis and multivariate logistic regression method were used to analyze the main influencing factors of occupational stress and mental health status of psychiatric managers. Results: The detection rate of anxiety and depression among 497 HIPCPs was 22.73% (113/497) and 58.95% (293/497), respectively. Gender and major were the influencing factors of depression (P=0.000, 0.001). Average working hours>52 hours per week and night shift days>1 days per week were the influencing factors of anxiety (P=0.035, 0.014). Average working hours>52 h per week, night shift days >1 d per week and different majors were the influencing factors of occupational stress (P=0.000, 0.025, 0.010). Multivariate logistic regression results showed that the risk of anxiety in those who worked more than 52 hours per week was 1.753 times that of those who worked less than 52 hours per week (P=0.038), and the risk of depression in women was 3.071 times that of men (P=0.006) . Conclusion: Working hours are an important influencing factor for occupational stress and anxiety among HIPCPs. In order to reduce the occurrence of occupational stress and mental health problems, it is necessary to strengthen psychological counseling for HIPCPs and balance work and rest.

[Effect of zinc oxide nanoparticles on hypoxia and pyroptosis of rat neutrophils].

Objective: To investigate the effects of zinc oxide nanoparticles (ZnO-NPs) on neutrophil hypoxia and pyroptosis through nucleotide binding of oligomeric domain-like receptor protein 3 (NLRP3) inflammasome, and to analyze the role of pyroptosis on respiratory tract inflammotion induced by ZnO-NPs. Methods: In October 2022, primary cultured neutrophils were obtained from the abdominal aortic blood of SPF adult healthy SD rats. The neutrophils were treated with ZnO-NPs solution (0, 5, 10, 20 µg/ml) at different concentrations, and hypoxia group (5% O(2)) was set up. Hypoxia and reactive oxygen species (ROS) levels were detected by flow cytometry, and the expression levels of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), cleaved Caspase-1 were measured by Western blot. The activity of lactic dehydrogenase (LDH) in the cell supernatant was measured by coloration, and the content of interleukin-1 beta (IL-1ß) in cell culture supernatant was detected by enzyme-linked immunosorbent assay (ELISA) . Results: Compared with the control group, hypoxia and ROS levels of neutrophils in hypoxia group and ZnO-NPs groups were significantly increased (P<0.05), and NLRP3, ASC, cleaved Caspase-1 protein expression levels, LDH activity and IL-1ß content were significantly increased (P<0.05). Compared with hypoxia group, hypoxia and ROS levels of neutrophils in 5 µg/ml and 10 µg/ml ZnO-NPs groups were significantly decreased (P<0.05), NLRP3, ASC, cleaved Caspase-1 protein expression levels, LDH activity, and IL-1ß content were decreased significantly (P<0.05). There were no significant differences in hypoxia, ROS levels, ASC, cleaved Caspase-1 protein expression levels, LDH activity, and IL-1ß content between the 20 µg/ml ZnO-NPs group and the hypoxia group (P>0.05) . Conclusion: ZnO-NPs treatment may activate the NLRP3 inflammasome to induce pyroptosis of neutrophils which may be related to ROS and hypoxia.

Confinement of Fractional Excitations in a Triangular Lattice Antiferromagnet.

High-resolution neutron and THz spectroscopies are used to study the magnetic excitation spectrum of Cs_{2}CoBr_{4}, a distorted-triangular-lattice antiferromagnet with nearly XY-type anisotropy. What was previously thought of as a broad excitation continuum [L. Facheris et al., Phys. Rev. Lett. 129, 087201 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.087201] is shown to be a series of dispersive bound states reminiscent of "Zeeman ladders" in quasi-one-dimensional Ising systems. At wave vectors where interchain interactions cancel at the mean field level, they can indeed be interpreted as bound finite-width kinks in individual chains. Elsewhere in the Brillouin zone their true two-dimensional structure and propagation are revealed.

Experimental Validation of a Kinetic Ballooning Mode in High-Performance High-Bootstrap Current Fraction Fusion Plasmas.

We report the observation of a set of coherent high frequency electromagnetic fluctuations that leads to a turbulence induced self-regulating phenomenon in the DIII-D high bootstrap current fraction plasma. The fluctuations have frequency of 130-220 kHz, the poloidal wavelength and phase velocity are 16-30 m^{-1} and ∼30 km/s, respectively, in the outboard midplane with the estimated toroidal mode number n∼5-9. The fluctuations are located in the internal transport barrier (ITB) region at large radius and are experimentally validated to be kinetic ballooning modes (KBM). Quasilinear estimation predicts the KBM to be able to drive experimental particle flux and non-negligible thermal flux, suggesting its significant role in regulating the ITB saturation.

Turbulence characteristics and flow dynamics impacts on the H-mode transition in favourable magnetic geometry with lower power threshold.

The L-H transition power threshold (PLH) in favourable magnetic geometry (ion ∇B drift pointing towards X-point) is much lower than in the unfavourable magnetic geometry (ion ∇B drift pointing away from X-point) on multiple tokamaks. In a systematic experiment on DIII-D, the ion ∇B drift direction was changed continuously from the unfavourable to favourable configuration during plasma discharges. During such process, the input neutral beam power was kept constant at a value that was above PLH for favourable configuration, but lower than PLH for unfavourable configuration. Toroidal field and plasma current were also kept constant and there was little change in the edge electron density ne and electron temperature Te profiles. The density fluctuation amplitude was reduced approaching the transition, while a large increase of turbulence Reynolds stress and flow shear were simultaneously observed. The turbulence decorrelation rate was found to increase as the ion ∇B drift direction was moving towards the favourable configuration, but the flow shear also increased and exceeded the turbulence decorrelation rate. These measurements demonstrate an important correlation between turbulence and turbulence-driven flow and a lowering of PLH, provide insights into the underlyingphysics behind the hidden parameters and inform a more complete physics-based model of the L-H transition power threshold. This article is part of a discussion meeting issue 'H-mode transition and pedestal studies in fusion plasmas'.

Emergent Majorana zero-modes in an intrinsic anti-ferromagnetic topological superconductor Mn2B2 monolayer.

Topological superconductors (TSCs) are an exotic field due to the existence of Majorana zero-modes (MZM) in the edge states that obey non-Abelian statistics and can be used to implement topological quantum computations, especially for two-dimensional (2D) materials. Here we predict manganese diboride (Mn2B2) as an intrinsic 2D anti-ferromagnetic (AFM) TSC based on the magnetic and electronic structures of Mn and B atoms. Once Mn2B2 ML enters a superconducting state, MZM will be induced by the spin-polarized helical gapless edge states. The Z2 topological non-trivial properties are confirmed by Wannier charge centers (WCC) and the platform of the spin Hall conductivity near the Fermi level. Phonon-electron coupling (EPC) implies s-wave superconductivity and the critical temperature (Tc) is 6.79 K.

57Fe Mössbauer and DFT study of the electronic and spatial structures of the iron(II) (pseudo)clathrochelates: the effect of ligand field strength.

Combined experimental 57Fe Mössbauer and theoretical DFT study of a series of iron(II)-centered (pseudo)macrobicyclic analogs and homologs was performed. The field strength of the corresponding (pseudo)encapsulating ligand was found to affect both the spin state of a caged iron(II) ion and the electron density at its nucleus. In a row of the iron(II) tris-dioximates, passing from the non-macrocyclic complex to its monocapped pseudomacrobicyclic analog caused an increase both in the ligand field strength and in the electron density at the Fe2+ ion, and, therefore, a decrease in the isomer shift (IS) value (so-called "semiclathrochelate effect"). Its macrobicyclization, giving the quasiaromatic cage complex, caused a further increase in the two former parameters and a decrease in IS (so-called "macrobicyclic effect"). The trend of their IS values was successfully predicted using the performed quantum-chemical calculations and the corresponding linear correlation with the electron density at their 57Fe nuclei was plotted. A variety of different functionals can be successfully used for such excellent prediction. The slope of this correlation was found to be unaffected by the used functional. In contrast, the predictions of both the sign and the values of quadrupole splitting (QS) for them, based on the theoretical calculations of EFG tensors, were found to be a real great challenge, which could not be solved at the moment even in the case of these C3-pseudosymmetric iron(II) complexes with known XRD structures. The latter experimental data allowed us to deduce a sign of the QSs for them. The straightforwarded molecular design of a (pseudo)encapsulating ligand is proposed to control both the spin state and the redox characteristics of an encapsulated metal ion.

Association between sarcopenia and prediabetes among non-elderly US adults.

AIM: To explore the specific association between sarcopenia and prediabetes based on large population samples. METHODS: A total of 16,116 U.S. adults aged 20-59 with dual energy X-ray absorptiometry (DXA) was identified from the National Health and Nutrition Examination Surveys (NHANES). Sarcopenia was defined according to appendicular skeletal muscle mass (ASM) adjusted for body mass index (BMI). Multivariable binary logistic regression models were used to ascertain odds ratios (ORs) for developing prediabetes. Stratified analyses were also performed. RESULTS: Prevalence of prediabetes was higher in the sarcopenia group (n = 1055) compared with the non-sarcopenia group (n = 15,061) (45.50% vs 28.74%, P < 0.001). Sarcopenia was strongly associated with an increased risk of prediabetes after full adjustment (OR = 1.21, 95CI%: 1.05, 1.39, P = 0.009). In the stratified analysis, this association remained significant independent of obesity, triglycerides, and low-density lipoprotein cholesterol levels. When sarcopenia subjects combined with obesity especially central obesity, the risk of prediabetes was the highest (OR = 2.63, 95CI%: 2.22, 3.11, P < 0.001). Furthermore, a greater proportion of any of impaired glucose tolerance (IGT) individuals was observed in the sarcopenia group compared to the non-sarcopenia group among prediabetes population (41.72% vs 24.06%, P < 0.001). CONCLUSIONS: Sarcopenia was positively associated with prevalent prediabetes especially IGT in the non-elderly. Moreover, synergistic interactions between the sarcopenia and obesity could greatly increase the risk of prediabetes.

Phenylacetylglutamine as a novel biomarker of type 2 diabetes with distal symmetric polyneuropathy by metabolomics.

PURPOSE: Type 2 diabetes mellitus (T2DM) with distal symmetric polyneuropathy (DSPN) is a disease involving the nervous system caused by metabolic disorder, while the metabolic spectrum and key metabolites remain poorly defined. METHODS: Plasma samples of 30 healthy controls, 30 T2DM patients, and 60 DSPN patients were subjected to nontargeted metabolomics. Potential biomarkers of DSPN were screened based on univariate and multivariate statistical analyses, ROC curve analysis, and logistic regression. Finally, another 22 patients with T2DM who developed DSPN after follow-up were selected for validation of the new biomarker based on target metabolomics. RESULTS: Compared with the control group and the T2DM group, 6 metabolites showed differences in the DSPN group (P < 0.05; FDR < 0.1; VIP > 1) and a rising step trend was observed. Among them, phenylacetylglutamine (PAG) and sorbitol displayed an excellent discriminatory ability and associated with disease severity. The verification results demonstrated that when T2DM progressed to DSPN, the phenylacetylglutamine content increased significantly (P = 0.004). CONCLUSION: The discovered and verified endogenous metabolite PAG may be a novel potential biomarker of DSPN and involved in the disease pathogenesis.

[Genome sequence analysis of two SARS-CoV-2 virus infections in Inner Mongolia, 2022].

The target gene sequences of the novel coronaviruses obtained by sequencing were compared with the reference sequences to analyze the genetic variation of the two cases of the novel coronaviruses from Inner Mongolia Autonomous Region in 2022 and to explore the sources of infection. The results showed that the two sequences belonged to different evolutionary branches, Delta (AY.122) and Omicron (BA.1.1), respectively. hCoV-19/Inner Mongolia/IVDC-591/2022 had 48 single nucleotide polymorphisms on the genome sequences, sharing 40 nucleotide mutation sites with a Mongolian strain; hCoV-19/Inner Mongolia/IVDC-592/2022 genome shared 57 nucleotide mutation sites with a UK strain, and the nucleotide mutation site identity was 100% (57/57). Phylogenetic analysis showed that the target gene sequences were not directly related to domestic novel coronavirus sequences during the same period, but were related to isolates from Europe and Mongolia.

[Analysis on the household secondary attack rates of the SARS-CoV-2 Delta variant and the associated factors].

Objective: To evaluate the household secondary attack rates of the SARS-CoV-2 Delta variant and the associated factors. Methods: A COVID-19 outbreak caused by the Delta variant occurred in Nanjing in July 2021. A total of 235 cases with current addresses in Nanjing were reported from 171 households. The subjects in this study were selected from household close contact(s) of infected cases. The information on household index cases and their contacts were collected, and the household secondary attack rate (HSAR) and the risk factors were analyzed by the multi-factor logistic regression model. Results: A total of 234 cases of household close contacts and 64 household secondary cases were reported from 103 households, and the HSAR was 27.4% (64/234, 95%CI:22.0% to 33.4%). The proportions of household size for 2 to 3, 4 to 5, and 6 to 9 were 64.1% (66), 26.2% (27) and 9.7% (10), respectively. A total of 35 cases of household cluster outbreaks were reported (35/103, 34.0%). The number of the first case in the household (FCH) was 103 and males accounted for 27.2% (28 cases), with the median age (Q1, Q3) of 49 (9, 56). The number of household close contacts was 234 and males accounted for 59.0% (138 cases), with the median age (Q1, Q3) of 42 (20, 55) and the median exposure period (Q1, Q3) of 3 (1, 3) days. The multi-factor logistic regression model showed that the higher HSAR was observed in the FCH with the features of airport staff (OR=2.913, 95%CI:1.469-5.774), detection from home quarantine screening (OR=6.795, 95%CI:1.761-26.219) and detection from mass screening (OR=4.239, 95%CI:1.098-16.368). Meanwhile, higher HSAR was observed in cases with longer household exposure (OR=1.221, 95%CI:1.040-1.432), non-vaccination (OR=2.963, 95%CI:1.288-6.813) and incomplete vaccinations (OR=2.842, 95%CI:0.925-8.731). Conclusion: The generation interval of the Delta variant is shortened, and the ability of transmission within the household is enhanced. In the outbreak in Nanjing, the associated factors of HSAR are occupation, detection route, vaccination and exposure period.

[Epidemiological investigation on the local epidemic situation in Zhengzhou High-Tech Zone caused by SARS-CoV-2 Delta variant].

This study collected epidemic data of COVID-19 in Zhengzhou from January 1 to January 20 in 2022. The epidemiological characteristics of the local epidemic in Zhengzhou High-tech Zone caused by the SARS-CoV-2 Delta variant were analyzed through epidemiological survey and big data analysis, which could provide a scientific basis for the prevention and control of the Delta variant. In detail, a total of 276 close contacts and 599 secondary close contacts were found in this study. The attack rate of close contacts and secondary close contacts was 5.43% (15/276) and 0.17% (1/599), respectively. There were 10 confirmed cases associated with the chain of transmission. Among them, the attack rates in close contacts of the first, second, third, fourth and fifth generation cases were 20.00% (5/25), 17.86% (5/28), 0.72% (1/139) and 14.81% (4/27), 0 (0/57), respectively. The attack rates in close contacts after sharing rooms/beds, having meals, having neighbor contacts, sharing vehicles with the patients, having same space contacts, and having work contacts were 26.67%, 9.10%, 8.33%, 4.55%, 1.43%, and 0 respectively. Collectively, the local epidemic situation in Zhengzhou High-tech Zone has an obvious family cluster. Prevention and control work should focus on decreasing family clusters of cases and community transmission.