Prevention and Control Strategies of Nosocomial Infection and Effectiveness Evaluation in a Tertiary Teaching Hospital during the Epidemic of COVID-19

Objective: To evaluate the role of prevention and control strategies for nosocomial infection in a tertiary teaching hospital during the sudden outbreak of Corona Virus Disease 2019 (COVID-19). Methods: The hospital initiated an emergency plan involving multi-departmental defense and control. It adopted a series of nosocomial infection prevention and control measures, including strengthening pre-examination and triage, optimizing the consultation process, improving the hospital’s architectural composition, implementing graded risk management, enhancing personal protection, and implementing staff training and supervision. Descriptive research was used to evaluate the short-term effects of these in-hospital prevention and control strategies. The analysis compared changes in related evaluation indicators between January 24, 2020 and February 12, 2020 (Chinese Lunar New Year’s Eve 2020 to lunar January 19) and the corresponding lunar period of the previous year. Results: Compared to the same period last year, the outpatient fever rate increased by 1.85-fold (P P Conclusion: The nosocomial infection prevention and control strategies implemented during this specific period improved the detection and control abilities for the COVID-19 source of infection and enhanced the compliance with measures. This likely contributed significantly to avoiding the occurrence of nosocomial infection.

Explosive eye injuries: characteristics, traumatic mechanisms, and prognostic factors for poor visual outcomes

Background: Explosions can produce blast waves, high-speed medium, thermal radiation, and chemical spatter,leading to complex and compound eye injuries. However, few studies have comprehensively investigated the clinical features of different eye injury types or possible risk factors for poor prognosis.Methods: We retrospectively reviewed all consecutive records of explosive eye injuries(1449 eyes in 1115 inpatients)in 14 tertiary referral hospitals in China over 12 years(between January 1, 2008 and December 31, 2019). Data on demographics, eye injury types, ocular findings, treatments, and factors affecting visual prognosis were extracted from a standardized database of eye injuries and statistically analyzed.Results: Mechanical ocular trauma accounted for 94.00% of explosion-related eye injuries, among which intraocular foreign bodies(IOFBs) resulted in 55.17% of open globe injuries(OGIs) and contusion caused 60.22% of close globe injuries(CGIs). Proliferative vitreous retinopathy(PVR) was more common in perforating(47.06%) and IOFB(26.84%)than in penetrating(8.79%) injuries, and more common with laceration(24.25%) than rupture(9.22%, P<0.01).However, no difference was observed between rupture and contusion. Ultimately, 9.59% of eyes were removed and the final vision was ≤4/200 in 45.82% of patients. Poor presenting vision [odds ratio(OR)=5.789], full-thickness laceration of the eyeball ≥5 mm(OR=3.665), vitreous hemorrhage(OR=3.474), IOFB(OR=3.510), non-mechanical eye injury(NMEI, OR=2.622), rupture(OR=2.362), traumatic optic neuropathy(OR=2.102), retinal detachment(RD,OR=2.033), endophthalmitis(OR=3.281), contusion(OR=1.679), ciliary body detachment(OR=6.592), zone Ⅲ OGI(OR=1.940), and PVR(OR=1.615) were significant negative predictors for poor visual outcomes(P<0.05).Conclusions: Explosion ocular trauma has complex mechanisms, with multiple eyes involved and poor prognosis. In lethal level Ⅰ explosion injuries, eyeball rupture is a serious condition, whereas contusion is more likely to improve. In level Ⅱ injuries, IOFBs are more harmful than penetrating injuries, and level Ⅳ represents burn-related eye injuries.PVR is more associated with penetrating mechanisms than with OGI. Identifying the risk predictors for visual prognosis can guide clinicians in the evaluation and treatment of ocular blast injuries.

Themes and Challenges in Making Urban Freight Distribution Sustainable

The purpose of this article is to explore and classify themes and challenges in making urban freight distribution sustainable.The study has a cross sectional design which started by a narrative literature review and analysis of a sample of related literature(like peer-reviewed articles and EU(European Union)documents).It ended with complementary discussion and recommendation for tackling the challenges.The results of the study illustrate eight and seven emerged categories of themes and challenges,respectively.It is concluded that there is great need for a packet of mixed strategies as well as a more holistic perspective where all actors together analyse and design future set-ups and operation of urban freight distribution.Such a holistic view is essential in order to:understand how different actors of the chain look upon sustainable urban freight distribution,avoid sub-optimal policies/governing rules,and suggest close-to-reality solutions for tackling the challenges.Freight distribution in urban areas is the main focus of this article.In addition,the study is demarcated to eco/environmental aspect of sustainability although it is impossible to completely exclude its interaction with economic and social aspects.The results offered in this paper provide a systematic structure for classifying issues related to sustainable urban freight distribution;something which will be beneficial for managers and policy-makers when they approach sustainable supply chain management challenges.This study provides a synthesized classification of themes and challenges which can guide researchers,industries,authorities,and policy-makers in future sustainability efforts.

Nonlinear Optimization Method of Ship Floating Condition Calculation in Wave Based on Vector

Ship floating condition in regular waves is calculated. New equations controlling any ship＇s floating condition are proposed by use of the vector operation. This form is a nonlinear optimization problem which can be solved using the penalty function method with constant coefficients. And the solving process is accelerated by dichotomy. During the solving process, the ship＇s displacement and buoyant centre have been calculated by the integration of the ship surface according to the waterline. The ship surface is described using an accumulative chord length theory in order to determine the displacement, the buoyancy center and the waterline. The draught forming the waterline at each station can be found out by calculating the intersection of the ship surface and the wave surface. The results of an example indicate that this method is exact and efficient. It can calculate the ship floating condition in regular waves as well as simplify the calculation and improve the computational efficiency and the precision of results.

Relationship between acute stress and sleep disorder in grass-root military personnel:Mediating effect of social support

Background: To explore the relationship between acute stress, social support and sleep disorder in grass-root military personnel, and construct the relational model through structural equation modeling. Methods: A total of 2,411 grass-root military personnel were randomly selected by cluster sampling, and administered the Chinese Military Personnel Sleep Disorder Scale, Military Acute Stress Scale and Social Support Rating Scale.Results: The total score of acute stress scale was positively correlated with the total score and factor scores of sleep disorder scale(r=0.209~0.465, P【0.01); The total score of social support scale was positively correlated with the total score of acute stress scale and the total score and factor scores of sleep disorder scale(r=0.356~0.537, P【0.01). The analysis of mediating effects showed that lack of social support partially mediated between acute stress and the factors of sleep disorder. The analysis of structural equation model showed that acute stress not only had a direct effect on sleep disorder(the path coefficient was 0.29, P=0.000), but also on lack of social support(the path coefficient was 0.39, P=0.000); lack of social support had a direct effect on sleep disorder(the path coefficient was 0.48, P=0.000).Conclusions: Acute stress and lack of social support are two significant factors of sleep disorder in grass-root military personnel. Well-established social support could alleviate sleep disorder induced by acute stress. Lack of social support was a partial mediator between acute stress and sleep disorder.

Kinetics of Formic Acid-autocatalyzed Preparation of Performic Acid in Aqueous Phase

Performic acid （PFA） is an oxidant used in chemical processing, synthesis and bleaching. The macro kinetic models of synthesis, hydrolysis and decomposition of PFA were investigated via formic acid-autocatalyzed reaction. It was found that the intrinsic activation energies of PFA synthesis and hydrolysis were 75.2 kJ·mol^-1 and 40.4 kJ·mol^-1 respectively. The observed activation energy of PFA decomposition was 95.4 kJ·mol^-1. The experi-mental results indicated that the decomposition of PFA was liable to occur even at the ambient temperature. Both the spontaneous decomposition and the radical-introduced decomposition contributed to the decomposition of PFA.

Identification of Axial Vibration Excitation Source in Vehicle Engine Crankshafts Using an Auto-regressive and Moving Average Model

Violent axial vibration of a vehicle engine crankshaft might lead to multiple defects to the engine.Much research on mechanism and control measures has been done on engines,such as using the dynamic stiffness matrix method,rayleigh differential method,and system matrix method.But the source of axial vibration has not been identified clearly because there are many excitation factors for the axial vibration of a crankshaft,such as coupled torsional-axial vibration and coupled bending-axial vibration,etc.In order to improve the calculation reliability and identify the excitation source of axial vibration of in vehicle engine crankshafts,this paper presents a method to identify the axial vibration excitation source of crankshafts for high speed diesel engines based on an auto-regressive and moving average（ARMA） model.Through determining initial moving average variables and measuring axial /bending/torsional vibrations of a crankshaft at the free-end of a 4-cylinder diesel engine,autoregressive spectrum analysis is applied to the measured vibration signal.The results show that the axial vibration of the crankshaft is mainly excited by coupled bending vibration at high speed.But at low speed,the axial vibration in some frequencies is excited primarily by torsional excitation.Through investigation of axial vibration source of engine crankshafts,calculation accuracy of vibration can be improved significantly.

Organization and implementation of mass medical rescue after an earthquake

Over the past century, over 40 earthquakes measuring ≥7 on the Richter scale have occurred worldwide; of those, 10 took place in China and killed 600,000 people(accounting for 53% of the total number of global deaths due to earthquakes). On May 12, 2008, an 8.0-magnitude earthquake occurred in Wenchuan, Sichuan Province. In this disaster, 69,000 people were killed, 18,000 people were reported missing, and 37,000 people were injured, including more than 10,000 who were seriously injured. Trauma was the most commonly observed type of injury, with fractures accounting for 74% of all injury cases. On April 14, 2010, a 7.1-magnitude earthquake occurred in Yushu, in Qinghai Province. In this disaster, 2,698 people were killed, 270 people were reported missing, and 11,000 people were injured, including more than 3,100 who were seriously injured. Fracture injury accounted for 58.4% of all injury cases. After each earthquake, the Chinese Army Medical Services responded promptly, according to the previously established guidelines, and sent out elite forces to the disaster areas, with the objectives of organizing, coordinating and participating in an efficient and evidence-based medical rescue effort. After the Wenchuan earthquake, 397 mobile medical service teams including 7,061 health workers were sent to the disaster areas. A total of 69,000 casualties were treated, and 22,000 surgeries were performed. After the Yushu earthquake, 25 mobile medical service teams involving 2,025 health workers were sent. They performed 1,635 surgeries and created an astounding outcome of "zero deaths" in the aftermath of the earthquake during their treatment of casualties in a high-altitude region. Within a week after each earthquake, the military teams rescued approximately 60% of the total number of rescued casualties and evacuated approximately 80% of the total number of evacuated sick or wounded victims, playing a critical role and making invaluable contributions to earthquake relief. The experience and lessons learned from the rescue efforts of the Chinese military after the two earthquakes have highlighted several key aspects in emergency medical rescue: 1) medical rescue theories must be updated; 2) military-civilian cooperation must be stressed; 3) professional rescue forces must be strengthened; 4) supporting facilities must be improved; and 5) international exchanges and cooperation must be deepened.

Fabrication and magnetic properties of NiFe_2O_4 nanorods

NiFe2O4 nanorods have been successfully synthesized via thermal treatment of the rod-like precursor fabricated by Ni-doped （x-FeOOH, which was enwrapped by the complex of citric acid and Niz~. The morphology evolution during the calcination of the precursor nanorods was investigated with transmission electron microscopy （TEM）, and the phase and the magnetic properties of samples were analyzed through X-ray diffraction （XRD） and vibrating sample magnetometer （VSM）. The results indicated that the diameter of the NiFe204 nanorods obtained ranged between 30 and 50 nm, and the length ranged between 2 and 3 um. As the calcination temperature was up to 600℃, the coercivity, saturation magnetization, and remanent magnetization of the samples were 36.1 kA.m^-1, 27.2 A.m2.kg^-1, and 5.3 A.m2.kg^-1, respectively. The NiFe2O4 nanorods prepared have higher shape anisotropy and superior magnetic properties than those with irregular shapes.

Study on Shielding Effectiveness of Fabric for Electromagnetic Wave with Different Inlaid Distances of Metal Fibres

The electremagnetic radicalization has become more serious. The shielding effectiveness of polyester fabrics with different inlaid distance of parallel metal fibres to electromagnetic wave was studied in this paper on special instrument made by ourselves. The results of test show that the fabric with different inlaid distances of metal fibres and the testing angle between electric field plane and parallel metal fibres of have obvious effect on the shielding effectiveness of electromagnetic wave.

Diester Derivatives from Chemically Modified Waste Cooking Oil as Substitute for Petroleum Based Lubricating Oils

In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and oxirane ring opening with carboxylic acids. The effects of the chain length of side chain groups on the viscosity, acid value, low temperature fluidity, thermo-oxidative stability, tribological properties and surface tension of diester derivatives were investigated. The results showed that increasing the chain length of side chain groups had a positive influence on the viscosity, viscosity index, acid value, pour point, friction coefficient and wear scar diameter along with a negative influence on the oxidation onset temperature, volatile loss, insoluble deposit, maximum non-seizure load and surface tension. These diester derivatives exhibited improved physicochemical and tribological properties that make themselves promising environmentally friendly biolubricant basestocks.

Study on Protective Clothing against SARS Using PTFE/Poly(ether-ester) Membrane

By means of texturing with organic conductive fiber, and then being treated with JAM-Y1 anti-bacteria agent, in the end, treated with the XL-550 waterproof agent, the PET fabric has permanent antistatic, anti-bacteria and waterproof and anti-oil properties. The PET fabric was laminated with PTFE membrane by paste dot coating, and then coated by Poly(ether-ester) solution in a direct process. The filter efficiency of NaCl aerosol, penetration property of poliomyelitis virus in liquid and animalcule in air of PET fabric laminated with PTFE membrane are measured. The properties show that the PET fabric laminated with PTFE membrane can separate SARS virus in air and liquid. The protective mechanism is also discussed in the article.

The Study on the Conductivity Performance and Shielding Effectiveness of Electro-magnetic Radiation of Polyethylene Film with Different Content of Carbon Black Particles

With the help of the testing apparatus made by ourselves for shielding electromagnetic radiation, the electric conductivity and shielding effectiveness of electromagnetic radiation of polyethylene film contained different content of carbon particles was systematically studied in this paper. The results indicate that the electric conductivity and shielding effectiveness of electromagnetic radiation of polyethylene /carbon film have closely relations with content of carbon black particles, which exists a critical content value as 14%～30% and its properties will have a tremendous change.

Military-civilian cooperative emergency response to infectious disease prevention and control in China

In recent years, the incidence of severe infectious diseases has increased, and the number of emerging infectious diseases continues to increase. The Chinese government and military forces have paid a great deal of attention to infectious disease prevention and control, and using military-civilian cooperation, they have successfully prevented numerous severe epidemic situations, such as severe acute respiratory syndrome(SARS), influenza A(H1N1), avian influenza H5N1 and H7N9, and Ebola hemorrhagic fever, while actively maintained public health, economic development, and national construction. This paper focuses on the mechanisms of the military-cooperative emergency response to infectious diseases–the joint working mechanism, the information-sharing mechanism, the research collaboration mechanism, and the joint disposal mechanism–and presents a sorted summary of the practices and experiences of cooperative emergency responses to infectious diseases. In the future, the Chinese military and the civilian sector will further strengthen the cooperative joint command system and emergency rescue force and will reinforce their collaborative information-sharing platform and technical equipment system to further improve military-civilian collaborative emergency infectious diseases disposal, advance the level of infectious disease prevention and control, and maintain public health.

Effects of laser power density on static and dynamic mechanical properties of dissimilar stainless steel welded joints

The mechanical properties of laser welded joints under impact loadings such as explosion and car crash etc. are critical for the engineering designs. The hardness, static and dynamic mechanical properties of AISI304 and AISI316L dissimilar stainless steel welded joints by CO2 laser were experimentally studied. The dynamic strainstress curves at the strain rate around 103 s-1 were obtained by the split Hopkinson tensile bar （SHTB）. The static mechanical properties of the welded joints have little changes with the laser power density and all fracture occurs at 316 L side. However, the strain rate sensitivity has a strong depen- dence on laser power density. The value of strain rate factor decreases with the increase of laser power density. The welded joint which may be applied for the impact loading can be obtained by reducing the laser power density in the case of welding quality assurance.

FAST SYMBOL-LEVEL SYNCHRONIZATION FOR TR-UWB SIGNALS USING DOUBLE HYBRID DS-TH SPREADING

A Transmitted Reference (TR) Ultra WideBand (UWB) signal with double hybrid Direct Sequence and Time Hopping (DS-TH) spreading is proposed and its symbol-level synchronization scheme is designed and analyzed. The proposed signaling format can significantly reduce the search space while reducing the spectral lines and eliminating inter-frame interference and multi-user inter- ference. Detailed analysis of the proposed scheme is carried out. Synchronization performance of the proposed signaling format in multipath channel is derived and supported by computer simulation. The search step which is closely associated with the delay of data modulated pulses is analyzed. Using the TH code, the proposed signaling format and synchronization scheme especially works well in moderate and low data rate systems.

Structure and Properties of Polytetrafluorethylene and Polyurethane Layered Membrane for Protective Clothing

This paper presents a new idea for intensifying protective and stretch recovery properties of micro porous polytetrafluorethylene and hydrophilic polyurethane (PTFE/PU) layered membrane through a co-stretching process. The structure and properties of co-stretching PTFE/PU layered membrane and coated PTFE/PU layered membrane by means of directly coating the PU on the PTFE membrane were investigated using Electron Microscope, Universal Materials Testing Machine, and the water vapor permeability (WVP) was measured according to absorption method of water vapor of GB/T 12704-91. Contrasted to PU coating process, the PU membrane on the co-stretching PTFE/PU membrane is nonporous because of heat treatment process, which can prevent the SARS virus from permeating the Co-stretching PTFE/PU membrane. The stretch and recovery properties of the Co-stretching PTFE/PU membrane is at least 66% after being stretched to 50% of its original length in transverse directions and that of the coated PTFE/PU membrane is 52%. The WVP of the Co-stretching PTFE/PU membrane is 13 523 g/24 h·m^2. The results suggest that when Co-stretching PTFE/PU membrane is laminated to a stretchable fabric, the fabric would have excellent stretch and recovery properties while waterproof and being permeable to water vapor. So, the Co-stretching PTFE/PU membrane laminated fabric will be a comfortable protective clothing material.

Experimental Investigation on Electromagnetic Attenuation by Low Pressure Radio-Frequency Plasma for Cavity Structure

This paper reports on an experiment designed to test electromagnetic（EM）attenuation by radio-frequency（RF）plasma for cavity structures.A plasma reactor,in the shape of a hollow cylinder,filled with argon gas at low pressure,driven by a RF power source,was produced by wave-transmitting material.The detailed attenuations of EM waves were investigated under different conditions：the incident frequency is 1-4 GHz,the RF power supply is 13.56 MHz and1.6（-3） k W,and the argon pressure is 75-200 Pa.The experimental results indicate that 5-15 d B return loss can be obtained.From a first estimation,the electron density in the experiment is approximately（1.5-2.2）×1016m（-3）and the collision frequency is about 11（-3）0 GHz.The return loss of EM waves was calculated using a finite-difference time-domain（FDTD）method and it was found that it has a similar development with measurement.It can be confirmed that RF plasma is useful in the stealth of cavity structures such as jet-engine inlet.

75 CASES OF SIMPLE OBESITY TREATED WITH AURICULAR AND BODY ACUPUNCTURE

The author adopted auricular and bodyacupuncture in the treatment of obesity withsatisfactory results as reported in the follow-ing:Clinical DataThe series of 75 cases were

75 CASES OF SIMPLE OBESITY TREATED WITH AURICULAR AND BODY ACUPUNCTURE

The author adopted auricular and body acupuncture in the treatment of obesity with satisfactory results as reported in the following: Clinical Data The series of 75 cases were diagnosed simple obesity for lack of evidence of any primary disease; age range was 17-65 years,