ABSTRACT
The recent outbreaks of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid international spread pose a global health emergency. The trimeric spike (S) glycoprotein interacts with its receptor human ACE2 to mediate viral entry into host-cells. Here we present cryo-EM structures of an uncharacterized tightly closed SARS-CoV-2 S-trimer and the ACE2-bound-S-trimer at 2.7-Å and 3.8-Å-resolution, respectively. The tightly closed S-trimer with inactivated fusion peptide may represent the ground prefusion state. ACE2 binding to the up receptor-binding domain (RBD) within S-trimer triggers continuous swing-motions of ACE2-RBD, resulting in conformational dynamics of S1 subunits. Noteworthy, SARS-CoV-2 S-trimer appears much more sensitive to ACE2-receptor than SARS-CoV S-trimer in terms of receptor-triggered transformation from the closed prefusion state to the fusion-prone open state, potentially contributing to the superior infectivity of SARS-CoV-2. We defined the RBD T470-T478 loop and residue Y505 as viral determinants for specific recognition of SARS-CoV-2 RBD by ACE2, and provided structural basis of the spike D614G-mutation induced enhanced infectivity. Our findings offer a thorough picture on the mechanism of ACE2-induced conformational transitions of S-trimer from ground prefusion state towards postfusion state, thereby providing important information for development of vaccines and therapeutics aimed to block receptor binding.Competing Interest StatementThe authors have declared no competing interest.View Full Text
ABSTRACT
Objective To investigate the status of patient safety culture cognition and safety nursing behavior among nurses and examine the influence of patient safety culture cognition on safety nursing behavior of nurses using structural equation model. Methods A total of 350 clinical nurses were recruited in a hospital in Dalian with multi-stage sampling method. Patient Safety Culture Assessing Scale, Safety Behavior Scale were delivered to the investigation object. Results The mean score of the patients safety culture was 4.09±0.47, which was above average;the total score of nurses′safety nursing behavior was 4.74 ± 0.31, which was at high level; the causality model of patient safety culture cognition and the safety nursing behavior was accepted (path coefficient=0.35,P<0.01). Conclusions Nurses′ patient safety culture cognition has a significant impact on safety nursing behavior. Hospital should cultivate the awareness of the patient safety culture, so as to promote the safety nursing behavior.
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Objective To explore the application of lentil lectin‐reactive alpha‐fetoprotein ratio (AFP‐L3% ) applied in the dif‐ferential diagnosis between hepatitis B infection of primary liver cancer and benign liver disease .Methods We included 108 cases of chronic HBV infection ,including 50 cases of primary liver cancer ,42 cases of cirrhosis ,16 cases of chronic hepatitis .Chemilumines‐cence detection was used to detect alpha‐fetoprotein (AFP) and AFP‐L3 content ,AFP‐L3 and the ratio of AFP (AFP‐L3% ) was calculated .Results AFP≥400 ng/mL as primary liver cancer diagnostic threshold ,the sensitivity and specificity were 36% ,84% , when used AFP‐L3% ≥ 10% as primary liver cancer diagnostic threshold ,the sensitivity and specificity were 62% ,83% . Conclusion AFP‐L3% is a better clinical indicator to distinguish between primary liver cancer and benign liver disease .AFP‐L3%can be used as a clinical indicator to differential diagnosis between HBV infection of primary liver cancer and benign liver disease .
ABSTRACT
Objective To explore influence of comfort care on life quality of breast cancer patients undergoing chemotherapy. Methods Hospitalized breast cancer patients(80 eases) after modified radical mastectomy were selected by convenience sampling method.They were randomly divided into the intervention group and the control group.The control group received conventional care.The intervention group was given comfort care based upon conventional care.The quality of life questionnaire-core 30 (QLQ-C30) by European organization for research and treatment of eancer(EORTC),hospital anxiety and depression scale (HADS) and self-designed questionnaire of satisfaction degree with nursing job were adopted for evaluation of the two groups. Results There was no significant difference in the life quality of patients between two groups before intervention (P＞0.05),but statistical difference was seen after intervention (P＜0.05).The incidence rate of depression and anxiety after the intervention in the intervention group was significantly lower than that of the control group (P＜0.05) and the satisfaction degree with nursing job was significantly higher (P＜0.05). Conclusions Comfort nursing intervention can improve the quality of nursing service,reduce anxiety and depression,improve the life quality of patients.
