DOUBLE LOOP ACTIVE VIBRATION CONTROL OF PNEUMATIC ISOLATOR WITH TWO SEPARATE CHAMBERS

A newly designed pneumatic spring with two separate chambers is promoted and double-loop active control is introduced to overcome the following drawbacks of passive pneumatic isolation： ① The low frequency resonances introduced into the system; ② Conflict between lower isolation frequency and stiffness high enough to limit quasi-static stroke;③ Inconsistent isolation level with different force load. The design of two separate chambers is for the purpose of tuning support frequency and force independently and each chamber is controlled by a different valve. The inner one of double-loop structure is pressure control, and in order to obtain good performance, nonlinearities compensation and motion flow rate compensation （MFRC） are added besides the basic cascade compensation, and the influence of tube length is studied. The outer loop has two functions： one is to eliminate the resonance caused by isolation support and to broaden the isolation frequency band by payload velocity feedback and base velocity feed forward, and the other is to tune support force and support stiffness simultaneously and independently, which means the support force will have no effect on support stiffness. Theoretical analysis and experiment results show that the three drawbacks are overcome simultaneously.

Impact of Multidisciplinary Collaborative Intervention on Isolation Implementation in Prevention and Control of Multi-drug Resistance Infection

Objective Contact precautions,especially the initiation of isolation,are important measures to prevent and control multidrug-resistant organisms(MDROs).However,the implementation in clinical practice remains weak.This study aimed to analyze the impact of multidisciplinary collaborative intervention on isolation implementation in multidrug-resistant infection,and determine the factors that affect the implementation of isolation measures.Methods A multidisciplinary collaborative intervention related to isolation was conducted at a teaching tertiary hospital in central China on November 1,2018.The information of 1338 patients with MDRO infection and colonization at 10 months before and after the intervention was collected.Then,the issuance of isolation orders was retrospectively analyzed.Univariate analysis and multivariate logistic regression analysis were performed to analyze the factors that affected the isolation implementation.Results The overall issuance rate of isolation orders was 61.21%,which increased from 33.12%to 75.88%(P<0.001)after the implementation of the multidisciplinary collaborative intervention.The intervention(P<0.001,OR=0.166)was a promoting factor for the issuance of isolation orders,in addition to the length of stay(P=0.004,OR=0.991),department(P=0.004),and microorganism(P=0.038).Conclusion The isolation implementation remains far lower than policy standards.Multidisciplinary collaborative interventions can effectively improve the compliance to isolation measures implemented by doctors,thereby promoting the standardized management of MDROs,and providing reference for further improving the quality of hospital infection management.

Seasonal and Tissue Age Influences on Endophytic Fungi of Pinus tabulaeformis (Pinaceae) in the Dongling Mountains, Beijing

Endophytic fungi associated with Pinus tabulaeformis Carr. were investigated in the Dongling Mountains of Beijing. A total of 16200 tissue segments of P. tabulaeformis from four sample collections were processed, and 10659 fungal isolates were recovered. The overall colonization and isolation rates of endophytic fungi from high to low were spring〉winter〉autumn〉summer and in different tissues were bark〉needle〉xylem, irrespective of sampling seasons. The colonization rates of endophytic fungi of needles increased with age in the four sample collections. There were no significant differences of the colonization rates of endophytic fungi among 1-, 2-, and 3-year-old bark and xylem, except for significantly lower colonization rates in 1-year-old bark than in 2- and 3-year-old bark in summer. A similar trend of the isolation rates of endophytic fungi occurred. A total of 24 fungal taxa were recorded, of these five taxa Alternaria alternata, Leptostroma sp., Pestalotiopsis besseyi, Phoma lingam, and Phomopsis archeri, were consistently isolated as the common fungi in each sample collection. Our results suggest that some fungi show a certain degree of tissue recurrence or specificity, and the composition of endophytic assemblages is not conspicuously influenced by the seasonal factor.