Nipah virus (NiV) and related viruses form a distinct henipavirus genus within the Paramyxoviridae family. NiV continues to spillover into the humans causing deadly outbreaks with increasing human-bat interaction. NiV encodes the large protein (L) and phosphoprotein (P) to form the viral RNA polymerase machinery. Their sequences show limited homologies to those of non-henipavirus paramyxoviruses. We report two cryo-electron microscopy (cryo-EM) structures of the Nipah virus (NiV) polymerase L-P complex, expressed and purified in either its full-length or truncated form. The structures resolve the RNA-dependent RNA polymerase (RdRp) and polyribonucleotidyl transferase (PRNTase) domains of the L protein, as well as a tetrameric P protein bundle bound to the L-RdRp domain. L-protein C-terminal regions are unresolved, indicating flexibility. Two PRNTase domain zinc-binding sites, conserved in most Mononegavirales, are confirmed essential for NiV polymerase activity. The structures further reveal anchoring of the P protein bundle and P protein X domain (XD) linkers on L, via an interaction pattern distinct among Paramyxoviridae. These interactions facilitate binding of a P protein XD linker in the nucleotide entry channel and distinct positioning of other XD linkers. We show that the disruption of the L-P interactions reduces NiV polymerase activity. The reported structures should facilitate rational antiviral-drug discovery and provide a guide for the functional study of NiV polymerase.
Nipah Virus/chemistry* ; Cryoelectron Microscopy ; Viral Proteins/genetics* ; RNA-Dependent RNA Polymerase/genetics* ; Phosphoproteins/genetics* ; Humans ; Models, Molecular ; Protein Binding

Transverse sinus is an important pathway of intracranial venous reflux,which is also crucial for maintaining cerebral circulation and stabilizing intracranial pressure.Transverse sinus stenosis(TSS)is the most common variation of transverse sinus,which might lead to changes in sinus hemodynamics and pressure and closely related to idiopathic intracranial hypertension,pulsatile tinnitus and chronic headache.The progresses in imaging researches of transverse sinus stenosis were reviewed in this article.

Objective:To investigate the hemodynamic characteristics of transverse sinus with sigmoid sinus wall dehiscence (SSWD) of pulsatile tinnitus (PT) based on 4D flow MRI.Methods:Retrospective analysis was performed on all patients admitted to Beijing Friendship Hospital, Capital Medical University from January 2019 to January 2021 for dehiscent sigmoid plate pulsatile tinnitus. A total of 26 patients (sides) who met the criteria and underwent 4D flow MRI were included. A total of 26 subjects (46 sides), matched 1∶1 according to gender and age, were included in the normal healthy control group. Nonparametric rank sum test, Student′s t test, and ANOVA were performed by SPSS 19.0 software. Binary Logistic regression was applied to the data with statistical significance. Results:There were more patients with dominant drainage on the affected side in PT group than in control group (73.1% vs. 42.3%). The incidence of transverse with a focal intraluminal filling defect and tapered stenosis was higher than that in control group (21.7% vs. 69.2%; 17.4% vs. 42.3%). Average through-plane velocity and maximum through-plane velocity in PT group were higher than those in control group [(33.75±13.88) cm/s vs. (15.84±7.21) cm/s; (93.19±33.55) cm/s vs. (40.40±14.40) cm/s]. The middle part and proximal end of Flow avg (ml/s) in PT group were larger than those in control group [4.69 (2.87; 5.62) ml/s vs. 2.76 (1.67; 4.99) ml/s; 3.41 (2.16; 5.47) ml/s vs. 2.67 (1.68; 4.41) ml/s]. In control group, the velocity of transverse sinus changed relatively gently, while in PT group, the velocity of proximal sinus increased significantly. Binary Logistic regression showed that SSWD PT was independently correlated with proximal maximum flow velocity [ OR=1.086(1.029-1.146), P=0.003]. Conclusion:4D flow MRI showed that the dominant drainage and higher velocity at the proximal end of the transverse sinus might be an important hemodynamic characteristics of dehiscent sigmoid plate pulsatile tinnitus.

Objective:To explore the construction and clinical practice of the training system for nurses in operating room subspecialty based on ORTCC model (including objectives, rules, training, assessment and culture), and to provide theoretical and practical guidance for the development of nursing subspecialty in operating room.Methods:This was a quasi-experimental study. The Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology was convenient to select 23 operating room nurses who rotated in orthopedic surgery rooms from January 2019 to June 2020 as the control group, and the traditional training model for specialized nurses in operating rooms was adopted. From July 2020 to December 2021, the 24 operating room nurses rotating orthopedic surgery rooms were selected as the experimental group, and ORTCC teaching mode was adopted. The degree of mastery of theoretical knowledge, standardization of operation skills, correct rate of standard preventive implementation and satisfaction rate of doctors of operating room nurses under two different training methods were compared.Results:The theoretical score of operating room nurses increased from (84.71 ± 5.70) points in the control group to (92.68 ± 3.64) points in the experimental group, and the skill score increased from (90.17 ± 4.69) points in the control group to (95.43 ± 2.61) points in the experimental group, with statistical significance ( t = 13.76, 5.64, both P<0.01). The satisfaction rate of surgeons to nurses′ surgical cooperation ability communication, cooperation ability and emergency treatment ability increased from 82.61%(19/23), 73.91%(17/23) and 78.26%(18/23) in the control group to 100.00%(24/24), 95.83% (24/24) and 100.00% (24/24) in the experimental group, respectively, with statistically significant differences ( t = 4.56, 4.45, 5.84, all P<0.05). Conclusions:The training system of operating room subspecialty nurses based on ORTCC model is conducive to improving the theoretical knowledge mastery, standard operation skills and doctor satisfaction rate of operating room nurses to the specialty and subspecialty, providing training basis for the development of operating room subspecialty, and worthy of clinical promotion.

Objective To investigate the value of high resolution CT (HRCT) in displaying the anatomic relationship between labyrinth segment of facial canal and cochlea.Methods Totally 110 patients (220 ears) who underwent HRCT were collected.The original images were transferred to workstation for image processing.MPR images were acquired.The anatomic relationship between labyrinth segment of facial canal and cochlea was observed in oblique coronal MPR images.The bony septum between labyrinth segment of facial canal and cochlea was assessed as definite defect (Type Ⅰ),doubtful defect (Type Ⅱ) or complete (Type Ⅲ),respectively.Results There were 71 ears (71/220,32.27％) of Type Ⅰ,diameters of bone fissure ranged from 0.3-1.3 mm (average diameters [0.64±0.26]mm),86 ears (86/220,39.09％) of Type Ⅱ and 63 ears (63/220,28.64％) of Type Ⅲ,with bony septum thickness ranged from 0.3-1.0 mm (average thickness [0.68±0.15]mm).No statistical difference of rates of the above three types was found between different genders,among age groups and between both side of ears (all P＞0.05).Conclusion HRCT is a reliable method to show the anatomic relationship between labyrinth segment of facial canal and cochlea.

Objective To explore the effective measures for the stability of micro-environmental indicators in clean operating department.Methods Professionals of clean technology were invited to participate in unit operation and maintenance of management.Besides, operating room managers conducted regular sampling analysis of five micro-environmental indicators, including temperature, humidity, differential pressure, illumination and decibel, in 100-level, 1 000-level, 10 000-level, 100 000-level clean operating rooms, and compared the test results with parameters of target environmental indicators regulated in national standards.Then the test results of annual bacteria subsidence from different operating rooms in clean operating department were compared.Results Under the management of professionals, the values of temperature, humidity, differential pressure, illumination and decibel from micro-environment in 100-level, 1 000-level, 10 000-level, 100 000-level clean operating rooms were in accordance with rated values in the industry with ( P>0.05);the annual bacteria subsidence in 100-level, 1 000-level, 10 000-level, 100 000-level clean operating rooms in 2013 was in accordance with the standards specified in GB50333 and clearly less than rated values.Conclusions Professional participating in the management and maintenance of micro-environment in clean operating department and irregular supervision and sampling test by operating room managers, the micro-environmental indicators in operation department can be well controlled.