Objective:To explore the epidemiological characteristic of a COVID-19 outbreak caused by 2019-nCoV Omicron variant BF.7 and other provinces imported in Shenzhen and analyze transmission chains and characteristics.Methods:Field epidemiological survey was conducted to identify the transmission chain, analyze the generation relationship among the cases. The 2019-nCoV nucleic acid positive samples were used for gene sequencing.Results:From 8 to 23 October, 2022, a total of 196 cases of COVID-19 were reported in Shenzhen, all the cases had epidemiological links. In the cases, 100 were men and 96 were women, with a median of age, M (Q1, Q3) was 33(25, 46) years. The outbreak was caused by traverlers initial cases infected with 2019-nCoV who returned to Shenzhen after traveling outside of Guangdong Province.There were four transmission chains, including the transmission in place of residence and neighbourhood, affecting 8 persons, transmission in social activity in the evening on 7 October, affecting 65 persons, transmission in work place on 8 October, affecting 48 persons, and transmission in a building near the work place, affecting 74 persons. The median of the incubation period of the infection, M ( Q1, Q3) was 1.44 (1.11, 2.17) days. The incubation period of indoor exposure less than that of the outdoor exposure, M ( Q1, Q3) was 1.38 (1.06, 1.84) and 1.95 (1.22, 2.99) days, respcetively ( Waldχ2=10.27, P=0.001). With the increase of case generation, the number and probability of gene mutation increased. In the same transmission chain, the proportion of having 1-3 mutation sites was high in the cases in the first generation. Conclusions:The transmission chains were clear in this epidemic. The incubation period of Omicron variant BF.7 infection was shorter, the transmission speed was faster, and the gene mutation rate was higher. It is necessary to conduct prompt response and strict disease control when epidemic occurs.

The effect of intra-operative mechanical ventilation modes on pulmonary outcomes after thoracic surgery with one-lung ventilation has not been well established. We evaluated the impact of three common ventilation modes on postoperative pulmonary complications in patients undergoing lung resection surgery. In this two-centre randomised controlled trial, 1224 adults scheduled for lung resection surgery with one-lung ventilation were randomised to one of three groups: volume-controlled ventilation; pressure-controlled ventilation; and pressure-control with volume guaranteed ventilation. Enhanced recovery after surgery pathways and lung-protective ventilation protocols were implemented in all groups. The primary outcome was a composite of postoperative pulmonary complications within the first seven postoperative days. The outcome occurred in 270 (22%), with 87 (21%) in the volume control group, 89 (22%) in the pressure control group and 94 (23%) in the pressure-control with volume guaranteed group (p = 0.831). The secondary outcomes also did not differ across study groups. In patients undergoing lung resection surgery with one-lung ventilation, the choice of ventilation mode did not influence the risk of developing postoperative pulmonary complications. This is the first randomised controlled trial examining the effect of three ventilation modes on pulmonary outcomes in patients undergoing lung resection surgery.

Objective To evaluate the intervention effects of response to heatwave in communities of four cities, China. Methods Baseline survey on heatwave and climate change related knowledge, attitude and practice (KAP) was conducted in the pilot communities in Harbin, Nanjing, Shenzhen and Chongqing,using face-to-face questionnaire interview in November,2011 to November,2013.Finally,1 604 residents were interviewed. Intervention measures were implemented in summers of 2013 and 2014, including delivering early warning information of heatwave health risk and launching health education and promotion. The second survey was conducted in same communities using the same questionnaire and sampling method as baseline survey in November, 2014, and 1 640 residents were interviewed. The Chi-square test was used to compare the demographic characteristics and KAP of community residents between before and after intervention,and the factors that affected the intervention effect were selected by logistic multiple stepwise regression model. Results The age of the residents interviewed before and after intervention was (46.4 ± 15.5) years and (45.0 ± 15.9) years, respectively. Overall, the residents' awareness rates of heatwave before and after intervention were 70.5% (1 131/1 604) and 82.9% (1 359/1 640) (χ2=69.40,P<0.001).The rate of residents who had wished to receive early warning information increased 6.3% (χ2=41.11, P<0.001), which reached 94.6% (1 551/1 604) after intervention from 88.3% (1 416/1 604) in baseline survey.Both heatwave health risk early warning and health education had big impacts to residents. There were 92.7% (1 105 residents) among the 1 192 residents who had received the early warning information arrange work and rest time according to the early warning information and 93.0% (1 231 residents) among the 1 323 residents who knew about health education activities being conducted in community thought that the community health education activities had made active role in protecting health from heatwaves.After a series of intervention,male had a effect on attitude about hot wave than female in Nanjing and Chongqing,OR(95% CI)were 1.48(1.02-2.16)and 1.45(1.18-2.05),respectively;compared with subjects below primary school education, people with college degree or above had higer KAP in all cities (ORs range from 1.18 to 2.05), P<0.05; regular physical exercise (ORs range from 1.39 to 2.70) also had profound impacts on KAP in all cities (P<0.05). Conclusions Early warning and health education were effective measures to enhance residents'response capacity to climate change.

Objective: To study the relations between neck/shoulder or low back pain and their daily behavioral habits among middle school students in Shenzhen. Methods: We randomly chose 3 952 students from 10 high schools in Shenzhen to complete the questionnaires. Data was gathered and analyzed, using the IBM SPSS 23.0. Results: Of the 3 952 participants, 20.3% had neck/shoulder pain and 15.2% had low back pain. Among students experienced neck/shoulder pain, female (25.3%), high school (24.5%) and boarding students (24.4%) experienced higher rates of neck/shoulder pain (P<0.05). Female students (17.9%) also had higher rate of low back pain (P<0.05). Results from logistic regression analysis showed that factors as: gender, type of school, taking naps on the desk, staying up late, self-perceived stress from learning, overloading homework, time spent on mobile phone and TV, spending long time on computer etc. were related to the neck/shoulder pain (P<0.05). Factors as: gender, naps on the desk, stay up late, self-perceived stress, overloading homework, time spent on mobile phone and TV etc., were related to low back pain (P<0.05). Conclusion: Neck/shoulder pain and low back pain were both commonly seen while high self-perceived stress, sedentary behaviors and poor sleeping habits were associated with both neck/shoulder and low back pain in high school students in Shenzhen.

Analyzer-Based Phase Contrast X-ray Imaging (ABPCXI) can provide high contrast images of biological tissues with exquisite sensitivity to the boundaries between tissues and a reduced tissue radiation dose, compared with conventional absorption radiography. In this study, ABPCXI has been successfully applied to the excised mouse lung, heart and stomach. The anatomical features of these tissues are clearly distinguishable. The results demonstrate that the ABPCXI technique can provide a new source of information related to biological microanatomy.

The physiology of hepatic hematopoiesis is largely unknown, although studies have indicated that vasoactive intestinal polypeptide (VIP) is involved in this disease. To validate this hypothesis, we assessed the effects of VIP on human cord blood CD34+ cells. We also measured VIP levels and the capacity of vasoactive intestinal polypeptide receptor (VIPR) to bind to VIP in the rat liver during different developmental phases. VIP inhibited the proliferation of cord blood-derived CD34(+) cells from concentrations of 10-7-10-12 M. The highest suppression was achieved with 10-8 M VIP at day 10. Intracellular levels of tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β1 in CD34(+) cells treated with VIP were increased by 50.70 and 43.46%, respectively. Variations in VIP levels in the rat fetal liver generally increased rapidly with the stage of fetal development. In addition, the affinity of VIPR for VIP increased from relatively low levels in the rat fetal liver and peaked at birth, after which it gradually decreased. VIP had a suppressive effect on the proliferation of human cord blood-derived CD34(+) cells, partially by increasing the production of TNF-α and TGF-β. Low VIP levels in the fetal liver and gradually increasing levels after birth may in part be responsible for suppressing hematopoietic stem cell and progenitor proliferation in the liver.

The effects of podophyllotoxin (PPT), etoposide (VP16), and teniposide (VM26) on the growth of Tetrahymena thermophila BF5 (T.t.BF5) was investigated by the TAM AIR isothermal microcalorimetric system. The extent and duration of toxic effects on T.t.BF5 metabolism were evaluated by studying the growth rate constant (k), inhibitory ratio (I), maximum heat-output power (P max), peak time of maximum heat-output power (t p), and total heat production (Q t). Experimental results showed that the value of t p increased and the value of k and P max decreased with the increasing compound concentrations. Furthermore, the growth rate constant k was linear with compound concentration. The corresponding I was obtained from different k values. According to the IC10 (the concentration of inhibitor when the inhibitory ratio is 10 %), the relative toxicity of the three compounds was PPT (IC10 = 49.6 μg mL−1) > VP16 (IC10 = 117.5 μg mL−1) > VM26 (IC10 = 359.1 μg mL−1). The preliminary investigation of structure–activity relationships showed that the thienyl group was likely responsible for reducing the toxicity of the compounds.

The Beijing Spectrometer (BES) detector is a general purpose solenoid detector at the Beijing Electron Positron Collider (BEPC) in Beijing, China, that has collected large numbers of J/ψ, ψ′, Ds, D and τ events. In this paper, we describe the recent upgrade of the initial BES detector (BESI) to the improved BESII detector.

Aim The trophic effect of CNTF on skeletal muscle atrophy and dysfunction reduced by denervation was investigated in SD rats. Methods SD rats transected sciatic nerve in right side hind limbs were injected CNTF subcutaneously for 20 days. Skeletal muscle wet weights, protein contents, muscle fiber cross-sectional areas, contract properties and degree of hind limb abnormalities were observed in the rats. Results (1) Administrating of CNTF (0.2 mg/kg) in sciatic nerve transected SD rats attenuated denervation-induced skeletal muscle fiber atrophy evidently, resulted in gastrocnemius in injury side an obvious increase in contract function, prevented the loss of weights and protein in denervated skeletal muscle, and ameliorated abnormalities in sciatic nerve cut limbs remarkably. (2) The myotrophic effect of 0.2 mg/kg CNTF is more effective than 0.05 mg/kg. (3) The sensitivity to CNTF varied in muscles of different type; slow twitch muscle (soleus muscle) reacted to CNTF stronger and quicker than twitch muscle (extensor digitorum longus). Conclusion CNTF significantly attenuates denervation-reduced skeletal muscle atrophy and dysfunction in SD rats, act an evident myotrophic effect on denervated skeletal muscle. And this effect may be exerted in a dosage dependent manner and varies with muscle type.

Purely leptonic decays of the charged D meson have been studied using the reaction e+e−→D∗+D− at a center of mass energy of 4.03 GeV. A search was performed for D→μνμ recoiling against a D0 or D+ which had been reconstructed from its hadronic decay products. A single event candidate was found in the reaction e+e−→D∗+D−, where D∗+→π+D0 with the D0→K−π+, and the recoiling D− decaying via D−→μ−ν̄μ. This yields a branching fraction value B(D→μνμ)=0.08−0.05−0.02+0.16+0.05%, and a corresponding value of the pseudoscalar decay constant fD=300−150−40+180+80 MeV.

The channels of J/ ψ decay into ΛΛ̄, ΛΛ̄γ and ΛΛ̄π0 are analyzed with 7.8 × 106 J/ ψ events collected by BES detector at BEPC Collider. The branching ratios for three channels and the angular distribution for the first channel are measured. The branching ratios are Br (J/ ψ→ΛΛ̄) = (1.08 ± 0.06 ± 0.24) × 10-3, Br (J/ ψ→ΛΛ̄γ) <1.6 × 10-4(90% CL) and Br (J/ψ→ΛΛ̄π0 ) = (2.3 ± 0.7 ± 0.8) × 10-4 respectively. The angular distribution for J/ψ→ΛΛ̄ is dN/dcosθ = N0 (1 + αcos2θ), α = 0.52 ± 0.33 ± 0.13.

The absolute inclusive branching fraction of D+s→φX+ has been measured from data collected by the BES detector at a center-of-mass energy of 4.03 GeV, corresponding to an integrated luminosity of 22.3 pb−1. At this energy, direct pair production e+e−→D+sD−s has been observed. We have selected Ds candidate events by reconstructing five hadronic decay modes D+s→φπ+, K0*K+, K0K+, f0π+ and K0K−π+π+ and have searched for inclusive φ’s in the recoiling D−s. We observed three recoiling φ’s in the 166.4 ± 31.8 Ds candidate events, which leads to the absolute branching fraction B(D+s→φX+)=(17.8+15.1−7.2+0.6−6.3)% and B(D+s→φπ+)=(3.6+3.1−1.6+0.4−1.3)%. Received 21 July 1997DOI:https://doi.org/10.1103/PhysRevD.57.28©1998 American Physical Society

The channels of J/psi decay into lambda(lambda)over-bar, lambda(lambda)over-bar-gamma and lambda(lambda)over-bar-pi(0) are analyzed with 7.8 x 10(6) J/psi events collected by BES detector at BEPC Collider. The branching ratios for three channels and the angular distribution for the first channel are measured. The branching ratios are Br (J/psi --> lambda(lambda)over-bar) = (1.08 +/- 0.06 +/- 0.24) x 10(-3), Br (J/psi --> lambda(lambda)over-bar-gamma) < 1.6 x 10(-4)(90% CL) and Br (J/psi --> lambda(lambda)over-bar>pi(0)) = (2.3 +/- 0.7 +/- 0.8) x 10(-4) respectively. The angular distribution for J/psi --> lambda(lambda)over-bar is dN/dcos theta = N-0 (1 + alpha cos(2) theta)alpha cos2 theta), alpha = 0.52 +/- 0.33 +/- 0.13.

Decays of the J/psi, resonance into the three-photon final state are investigated. Branching ratios for the decays of J/psi --> gamma pi(0) and J/psi --> gamma eta' are determined to be Br(J/psi --> gamma pi(0)) = (4.6 +/- 1.1) x 10(-5) and Br(J/psi --> gamma eta') = (4.12 +/- 0.82) x 10(-3). The ratio of the two decay widths, Gamma(J/psi --> gamma eta') / Gamma(J/psi --> gamma eta), is 4.79 +/- 0.85. This value agrees well with the predictions of the two theoretical models.

The mean multiplicities of mesons pi(+/-), pi(0), K+/-, K-S(0), rho(0), K*(0), M*(+/-), and phi and baryons p, Xi(+/-), and Sigma(+/-) (1385) are measured for the first time at J/psi region with 200,000 events collected at the BEPC with the BES detector. The results are compatible with LUND and Shandong phenomenological models, Based on the experimental results, the strangeness suppression factor s/u and spin suppression factor V(V + P) can be calculated to be similar to 0.3 and similar to 0.3-0.5, respectively, which are in goad agreement with those given by the ARGUS Collaboration in the Upsilon region. This indicates that the SU(6) breaking is consistent in the energy region from J/psi to Upsilon.