• Users Online: 385
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
ORIGINAL ARTICLE
Year : 2014  |  Volume : 2  |  Issue : 1  |  Page : 44-49

Hospital safety index (HSI) analysis in confronting disasters: A case study from Iran


1 Department of Family Health, Health Metric Research Center, Iranian Institute for Health Sciences Research, Iranian Academic Center for Education, Culture and Research, Tehran, Iran
2 Risk Management Research Centre, International Institute of Earthquake Engineering and Seismology, Tehran, Iran
3 Department of Health Services Management, Science and Research Branch, Azad Islamic University, Tehran, Iran

Date of Web Publication25-Jun-2014

Correspondence Address:
Katayoun Jahangiri
Department of Family Health, Health Metric Research Center, Iranian Institute for Health Sciences Research, ACECR, Tehran
Iran
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/2347-9019.135368

Rights and Permissions
  Abstract 

Background: The ability of hospitals to continue functioning without interruption in disaster situations is a matter of life and death. The Hospital Safety Index (HSI) provides an overview of the probability of a hospital or healthcare facility to remain operational in emergency situations. Aims: This study has been performed in one of the hospitals associated with Social Security Organization in Tehran in order to assess the HSI in disasters. HSI helps authorities to quickly determine where interventions can improve safety. Materials and Methods: In this applied study, both qualitative and quantitative methods were used. Settings and Design: A specialized hospital in Tehran was studied regarding its structural, nonstructural and functional aspects using the World Health Organization/Pan American Health Organization (WHO/PAHO) standard checklists. Various wards and personnel of the hospital were included in this study. Statistical Analysis Used: Different types of hazards were analyzed, which are related to the location of the hospital. For determining the amount of risk in different wards, the occurring probability of each risk was scored based on the section status, previous records and events according to the Likert scale in one of the 4 levels and the total scores was considered as the section risk amount. Afterward, among each sections with similar tasks (administrative, financial, managerial and professional, supportive, clinical, surgery room and intensive care unit, emergency unit, and inpatient sections), the least and most amount of risk were clarified with regard to the following scores. Regarding the total scores, the minimum risk amount was 17 and the maximum was 68 in each section. If the total score was less than 17, no risk (safe), 17-34 low risk, 35-52 moderate risk, and in case of 53-70, the high risk was considered for that section. Results: According to the results, the final Hospital Safety Index score places this hospital in category "C" among three existing classifications of safety, which means that the hospital's current safety levels are inadequate to protect the lives of patients and hospital staff during and after a disaster. Conclusions: Urgent intervention measures and rapid assessment will give decision-makers a starting point to identify priorities in order to reduce risk and vulnerability in hospitals and health care facilities.

Keywords: Disasters, functional capacity, Hospital Safety Index, nonstrutural safety, strutural safety


How to cite this article:
Jahangiri K, Izadkhah YO, Lari A. Hospital safety index (HSI) analysis in confronting disasters: A case study from Iran. Int J Health Syst Disaster Manage 2014;2:44-9

How to cite this URL:
Jahangiri K, Izadkhah YO, Lari A. Hospital safety index (HSI) analysis in confronting disasters: A case study from Iran. Int J Health Syst Disaster Manage [serial online] 2014 [cited 2018 May 20];2:44-9. Available from: http://www.ijhsdm.org/text.asp?2014/2/1/44/135368


  Introduction Top


The Hyogo Framework for Action 2005-2015 (HFA) included the following measure in order to reduce the underlying risk factors as a part of social and economic development practices:

'Integrate disaster risk reduction planning into the health sector; promote the goal of "hospitals safe from disaster" by ensuring that all new hospitals are built with a level of resilience that strengthens their capacity to remain functional in disaster situations and implement mitigation, measures to reinforce existing health facilities, particularly those providing primary health care'. It also aims at protecting and strengthening critical public facilities including physical infrastructure, clinics, hospitals, etc. [1]

While crisis occurs, the vital services of society should be able to support the crisis survivors especially in the minutes and hours following an unexpected event. [2] Among the organizations and involving institutes, healthcare facilities especially hospitals play the most important role as an essential facility for providing services to those needed. [3] There is an expanded expectation that these centers must be designed in a manner to be able to function during and after a disaster. [4] According to PAHO (2008), in designing new, safe hospitals, there are three safety objectives:

  • To protect the life of patients, visitors, and hospital staff,
  • To protect the investment in equipment and furnishings,
  • To protect the performance of the hospital or the healthcare facility.


The aim of the "Hospitals Safe from Disasters" strategy is therefore to ensure that hospitals will not only remain functional in case of a disaster, but that they can function effectively and without interruption. In addition, hospitals and health care facilities are highly vulnerable because of the factors such as complexity, occupancy, critical supplies, heavy objects, hazardous materials and external dependence. The importance of hospitals can be seen in the economic loss and damage they may face. A reliable and comprehensive hospital assessment can be carried out only by taking into account all three main categories of vulnerability as in the following order: (a) structural; (b) nonstructural; and (c) administrative/organizational. [5]

In order to achieve this assessment, the development of the HSI is a very important step towards the goal of less vulnerable hospitals. Building the safe hospitals, which can keep their efficiency and function in crisis has always been a serious challenge for countries. Therefore, it is important to measure the safety level of hospitals in disaster situations as a part to decrease the risk in health section. [2] With HSI, an image of the current position and probable scenarios in crisis occurring time will be obtained, based on the structural, nonstructural and functional aspects of a hospital. In this way, the response strength of each system in major emergencies can be measured and the necessary and needed information can be submitted to the policy makers. [6] Therefore, HSI is not only a tool for making technical assessments, but it also provides a new approach to disaster prevention and mitigation for the health sector. Calculating the safety score allows the hospital to establish maintenance and monitoring routines and consider various and necessary measures to improve safety in the medium term. [2] Therefore, the reinforcement of structural, nonstructural and functional components of hospital, as the most important centers that should be immediately answerable to crucial needs after disasters, should be preferred. [7]

In this regard, the PAHO Disaster Mitigation Advisory Group (DIMAG) and national experts came together to devise a method for quick and inexpensive evaluation of hospitals. Using a checklist helps to assess different variables and safety standards for a hospital. A scoring system assigns the relative importance of each variable, which, when calculated, gives a numeric value to the probability that a hospital can survive and continue to function in a disaster. The HSI not only estimates the functional capacity of a hospital during and after an emergency, but it provides ranges that help authorities determine which facilities do need urgent interventions. Priority might be given to a facility where the safety of occupants is determined to be at risk during a disaster or to a facility where the equipment is at risk, and where maintenance is needed. HSI is not an "all or nothing" approach to hospital safety, but it allows for improvement in a facility over time. The index does not replace an in-depth vulnerability assessment, but it helps authorities to quickly determine where interventions can improve safety. It also provides an overview of the probability of a hospital or healthcare facility to remain functional in emergency situation, taking into account the environment and the health services network to which it belongs. As a comparison, it is like an out-of-focus snapshot of a hospital and it shows enough of the basic features to allow us to quickly confirm or reject the presence of imminent risks. [2] For this purpose, in this study it was tried to perform measures for reducing the risk to people's life and property loss through HSI calculation in one of the Social Security Organization hospitals in Tehran.


  Materials and Methods Top


The case study in this paper is based on the applied research, which has made use of both qualitative and quantitative methods. Two forms were used: Form No. 1 consisted of general information about the hospital (case study). Form No. 2 included the "Safe Hospitals Checklist". This checklist is used for preliminary diagnosis of the hospital's safety in disasters. It includes 145 variables, each with three safety levels: low, moderate, and high. It is divided into four sections or modules:

  • Geographic location of the hospital;
  • Structural safety;
  • Nonstructural safety;
  • Functional capacity.


In this regard, different types of hazards were analyzed (geological, hydro-meteorological, social, environmental, chemical and technical) which are related to the location of the hospital. The extent of hospital exposure is considered to be directly proportional to the probability of the occurrence of a hazard and its magnitude. In this way, they can be classified as high (high probability of a hazard taking place or high-magnitude hazard), moderate (moderate probability of a moderate magnitude hazard) and low (low probability or a hazard of low magnitude). [2]

Also for the structural safety analysis in this study, the PAHO standard was used, in which HSI and risk-taking level can be determined. For input gathering and completing the checklists, observations, survey and interviews were also used.

The nonstructural risk rating included the following [5] :

'Life safety (LS) risk: The risk of being injured by the item. This does not include the overall impact on safety systems in a building, such as loss of emergency power in a hospital or loss of fire detection capability. These disruptions of service are covered under loss of function below:

  • Property loss (PL) risk: The risk of incurring a repair or replacement cost because of damage to the item. This property loss, as used here, includes the cost of mending a broken pipe but not the indirect cost of damage due to leaked water, and includes the cost of repairing a computer but not any loss of business revenue due to computer downtime. These indirect effects cannot be estimated here on a generic basis
  • Loss of function (LF) risk: The risk that the item will not function because it has been damaged. This includes some consideration of the impact of this loss of function of the component on the operation of an ordinary occupancy building. Not included are off-site effects, such as the loss of function of a piece of equipment because of a citywide power cut. Losses of power, water and other utilities are real problems to consider but are outside the scope of the item-by-item ratings here.


For determining the amount of risk in different sections of the hospital, the occurring probability of each risk was scored based on the section status, previous records and events according to the Likert scale in one of the 4 levels (no risk = 1, low risk = 2, moderate risk = 3, high risk = 4), and the total scores was considered as the section risk amount. Afterward, among each sections with similar tasks (administrative, financial, managerial and professional, supportive, clinical, surgery room and intensive care unit, emergency unit, and inpatient sections), the least and most amount of risk were clarified with regard to the following scores. Regarding the total scores, the minimum risk amount was 17 and the maximum was 68 in each section. If the total score was less than 17, no risk (safe), 17-34 low risk, 35-52 moderate risk, and in case of 53-70, the high risk was considered for that section.

For examining the risk amount in structural dimension, (vulnerability category low = 2, moderate = 3, and high = 4) were used. Then, using the average of total assessing items, the structural vulnerability level was clarified. Using PAHO category, the vulnerability level of each section (low, moderate, and high) is determined. When the total score was 2/5-3/5, the hospital structural vulnerability was weak, in case of 3/6-4/5 it was moderate, and when it showed 4/6 and more, the vulnerability was considered in a high level.

The below formula was used for assessing the non-structural and functional vulnerability amount (based on PAHO).

TPL (total property loss) = [NL (1) + NM (2) + NH (3)]/NE

TLS (total life safety) = [NL (1) + NM (2) + NH (3)]/NE

When NL, NM, NH are low, moderate and high, respectively and NE is the number of elements. [8]

Internally, each of the services provided by the hospital will be of greater or lesser importance in the management of an emergency. In an emergency situation, the importance of medical services can be rated as: 1) dispensable, 2) preferable, 3) necessary, 4) very necessary and 5) indispensable [Table 1]. Using [Table 1], the vulnerability of each section (low, moderate and high) was determined. Structural, non-structural and functional factors were weighted based on their importance during the disaster occurrence. These scores were 50% of the total score index for structural, 30% for non-structural and 20% for functional components.
Table 1: Priorities of hospital sections regarding the safety condition in disastrous situations

Click here to view


The vulnerability/consequences level is determined according to the ranges of TPL or TLF values given in [Table 2]. [9] For input analysis, Statistical Package for the Social Sciences (SPSS version 16.0), statistical software was used.
Table 2: Level of vulnerability/consequences

Click here to view


To conclude, regarding the total score, hospitals and healthcare facilities are in one of three of following classification regarding safety, [2] :

Classification A: Those centers, which are considered to be able to protect their residents safely and can continue their activities in disasters are in this group (safety index 0.66-1).

Classification B: In this group, there are centers that can resist against a crisis, but their equipment and vital services are exposed to danger (safety index 0.36-0.65).

Classification C: Centers whose resident's life and safety are exposed to danger in crisis and urgent intervention measures are needed (safety index 0-0.35).

The HSI of the under-examined hospital will be explored more in the following sections.


  Results Top


In general, it can be said that natural disasters are not considered as the only cause of functional and physical collapse of a facility and the probable resulting deaths. Most of the time, hospitals are built without considering the hazard risks into account and when maintenance is neglected, systems deteriorate over time. Functional breakdown is one of the main causes for service interruption in hospitals after a disaster. Meanwhile, it should be mentioned that only a small proportion of hospitals are put out of service because of the structural damage.

In this study, the under examined hospital consisted of 4 buildings, including various sections such as clinic, emergency unit, admission unit and payment office, ICU, operation room, laboratory, radiology, physiotherapy, inpatient sections, nutrition unit, warehouse, information technology, administrative and financial units, transportation and equipment section, discharge unit, income, facility management unit, library, clinical engineering, and medical record office.

Based on the rapid visual assessment, the hospital structural vulnerability was high, in which the highest vulnerability level was related to building No. 1. For more precise results, a quantitative assessment using architectural and engineering methods is also needed which is not in the scope of this study. Among the hospital different sections, the manager office, transportation unit, pharmacy, and sterilization had the least risk threat, and the medical record office, medical record office, installations unit, laboratory unit, infectious disease clinic and inpatient section had categorized at the highest risk.

In the non-structural vulnerability from the equipment and furniture dimensions, it was observed that the general clinic, pharmacy, manager office, transportation, and intensive care unit had the least vulnerability level and the infectious disease clinic, physiotherapy; medical record office, clinical engineering and inpatient section experienced the highest vulnerability. As for nonstructural vulnerability, units from the architecture dimension, cardiology and general clinics, pharmacy, manger office, transportation, and the operation room had the least vulnerability level and the infectious disease clinic, physiotherapy, medical record office, clinical engineering and the inpatient section had the highest level of vulnerability.

In functional vulnerability, from the disaster management dimension, the general clinic and anesthetist consultant, pharmacy, personnel unit, transport office, central sterilization room (CSR) and inpatient section have the least, and infectious disease clinic, laboratory, medical record office, equipment and operation rooms and emergency ward had the highest vulnerability level. In functional vulnerability of units, from the resource aspect, general clinic, pharmacy, sterilization and intensive care unit had the least, and finally the infectious disease clinic, physiotherapy, operation rooms and emergency care had the highest vulnerability level.


  Conclusion Top


In this study, the nonstructural vulnerability including furnishing, administrative level and architecture equipment was almost moderate but the architecture components were more vulnerable. In this regard, Seyyedin et al., [10] also examined the vulnerability of a selective hospital facing a disaster. From the nonstructural dimension, it was revealed that the hospital vulnerability was at a moderate level. It should be noted that for safety enhancement in equipment and furniture sections, various stabilizing methods can be used such as, shunts installation, using screwing bolts, locking commodes, as well as fastening the shelves and computer equipment to a proper wall.

Since destruction of architecture components during a disaster could make a serious dysfunction in a hospital, it is highly important to determine the vulnerability amount of this component in hospital in order to decrease the risk. Among the architecture components in this survey, the entrance and exit routes, windows and glasses can be mentioned. Shojaie [11] has examined the emergency exit system in the educational hospitals of Iran Medical Science University and has declared that emergency exit routes have been almost determined in all hospital routes, but the guiding signs and boards were not clearly observed in all of them. In this study, none of the buildings in the hospital had lead to emergency exit routes. Although, there were more than one entrance and exit door in some parts of the hospital, it was only possible to make use of one door, since other doors were locked or it was impossible or difficult to access the door and the exit route. Also, in a study in a Social Security hospital of Khorramabad city, Malekshahi and Mardani [12] explained that 90% sections of this hospital had only one entrance and exit door, and in 10% remaining sections, the doors were locked. In case of emergency cases for evacuation in a disaster, the patients and staff need minimum 10 minutes to reach the open area. On the other hand, hospital doors and windows were not strong enough and therefore needed to be painted and lubricated. Meanwhile, an assessment in children's hospital in Skopje showed that glasses are the most dangerous elements in hospital building and use of window-panes near the partitions and separators could be very dangerous. [8] Also in the current study, doors and windows lacked the proper strength and in case the glasses were broken due to earthquake, there was the probability of dangers resulting from the shooting of glass bits. Therefore, it is recommended to cover glasses of windows and partitions, especially in crucial areas such as emergency and intensive care unit with a window firm to decrease the danger of shooting glasses during earthquakes.

In the 1994 Northridge California earthquake, electricity cut was the main cause of patients' evacuation in 14 hospitals., [13] In the current study, required electricity of the hospital was provided by the public network and electric generator provided 100% electricity of hospital in case of its cut. Moreover, another energy providing source should be considered for lighting special parts of hospital such as emergency care, and operation room during the electricity cut.

For providing the required water in case of disaster occurrence, the case study hospital had two sources of ground water, each had 12,000 liter capacity. After evaluating the water system of another hospital in Tehran named Shahid Labafi hospital, it was revealed that the main water consumption is from urban water source with a 80000 liter storing water reservoir and a smaller reservoir for the hospital dialyze section.

In Skopje children's hospital, it was shown that medical gases from the central medical unit were accessible via plumbing network. [8] In evaluating medical gases status, in the current study, the medical gas is the gas capsule. Hospital had 44 capsules, capacity 40 liter, 30 capsules, capacity 20 liter and 20 capsules with capacity of 10 liter. In various sections, there were 20 and 10 liter capsules and for providing the central oxygen capsule, the 40 liter capsules were used. Storing these capsules was allowed for only three days.

Moreover, the under study hospital communication system was not satisfactory and the only communication tools of hospital was telephone and pager. Also, a replacing location for communication center has not been considered and controlling system for the equipment and communication cables was not suitable. Shojaie in a similar survey relevant to evaluating different systems in under studied hospitals stated that a few of them have telephone, pager and wireless and other ones do not have wireless and only have telephone and pager and communication system in this hospital is not suitable. [11] In evaluating fire extinguishing system, it can be noted that, in all parts of under study hospital, detectors were installed, but they were inactive. In this hospital, sprinkler fire system (an automatic system) was not used. A fire sprinkler system is an active fire protection, consisting of a water supply system, providing adequate pressure and flow rate to a water distribution piping system, on which fire sprinklers are connected. Therefore, it is suggested to use it in some parts such as kitchen, warehouse and laboratory in which the probability of fire accident risk is high. Fire fight capsules have also been installed in all parts and sections of the hospital's walls vertically. But these capsules were sizeable and heavy and it was not possible to be used by women in the case of an accident. Therefore, it is recommended to use smaller capsules.

The under study hospital heating system was radiator and the cooling system was chiller. Air conditioning system of all parts of mentioned hospital was air ventilation, which does not function properly in some sections of the hospital such as clinic and care units and therefore, more strong conditioning system should be installed. The engine house of this hospital was old and poorly operated. Pipes, connections and valves of engine room are continually being repaired and renovated. Engine room and its equipment should be fundamentally repaired. In a similar study, Amini Ghazvini [14] declared that the heating, cooling and air conditioning system of a private hospital in Tehran needs to be installed better and should be fasten to the ceiling or the wall. In the current case study, the hospital functional (managerial) vulnerability is almost moderate. The majority of problems in this hospital were relevant to the functional (managerial) issues, related to the lack of financial sources and suitable non-programming source management. Amini Ghazvini in his study stated that although source applicability was at a desirable level, but there was no program for source management in emergency conditions.

Hospitals are highly complex facilities, which provides health care as well as functions as a hotel (inpatients), an office building (medical staff and administration), a laboratory and a warehouse. Hospitals have a high level of occupancy (patients, medical and support staff, visitors) including expensive medical equipment. As mentioned, although hospitals are essential for dealing with disasters, their complexity, occupancy level and specific equipment and installation system also make them vulnerable in various aspects: structural (load bearing system), nonstructural (architectural elements, installation and equipment) and administrative (organization of function space, staff, procedures, etc).

It is evident that emergencies require an increase in treatment capacity, and a hospital must be ready for optimal use of its existing resources. A hospital must also ensure that trained personnel are available to provide high quality, compassionate, and suitable treatment for those injured in a disaster. Given the importance of an efficient response to emergencies and the need for a functional health care infrastructure in the aftermath of a disaster, hospital administrators must consider all aspects of the hospital vulnerability. In areas prone to seismic activity, both existing and planned hospitals must comply with the seismic design codes. These are intended to ensure the safety of buildings' occupants and to allow facilities to stay functional during and after the earthquakes. Various methods for assessing the vulnerability of a hospital exist, which differ in cost, complexity and precision. In this paper, with regard to the obtained HSI, the under examined hospital is categorized in classification "C" mentioned in methodology section, which means that the vulnerability level of this hospital is high. This is a central hospital where resident's life and safety are exposed to danger during and after a disaster. Therefore, interventional urgent actions are needed in order to decrease the expected harm and danger due to probable future earthquakes.


  Acknowledgment Top


Hereby, the authors would like to thank the respected authorities in Social Security Organization, Tehran branch, especially the assistance of Mr. Rezaie. With regard to the ethical standards, some information related to the under examined hospital including its name and detailed findings are kept confidential by the researchers, as requested.

 
  References Top

1."Final report of the world conference on disaster reduction (A/CONF,206/6)Hyogo Framework for Action 2005-2015: Building the resilience of nations and communities to disasters". 16 Mar 2005; p. 11. Available in: www. unisdr.org/we/inform/publications/1037.  Back to cited text no. 1
    
2.PAHO . Hospital safety index guide for evaluators. Series Hospitals Safe from Disasters, 1. Washington DC. 2008; p. 107. Available in: new.paho.org/ disasters/index.php?option=com_docman&task=.  Back to cited text no. 2
    
3.Aboalghasemi H, Forotan Gh, Radfar MH, Amid A. Activities of health clinics in the Islamic revolution guards in Bam earthquake. J Med 2003;4:253-8. [In Persian].  Back to cited text no. 3
    
4.Akhavan MJ, Adibnejad S, Mousavi-Naaeni SM. Introducing Hospital mergency Incident Command System (HEICS) and HEICS Implementation in Iran Hospitals. Journal of Military Medicine. 2005;7:167-75.  Back to cited text no. 4
    
5.WHO. Health facility seismic vulnerability evaluation. Regional Office, Europe; 2006. p. 17. Available in: www.euro.who.int/__data/.../e88525.pdf.  Back to cited text no. 5
    
6.Jahangiri K. Principles of disaster management. 1 st ed. Tehran: Iran Crescent Scientific and Applied Sciences Institute [In Persian]; 2009:168-9.  Back to cited text no. 6
    
7.Jaffari Sissi B. Seismic retrofitting of steel buildings (Case study in Tabriz hospitals). Earthquake Engineering, International Institute of Seismology and Earthquake Engineering, Tehran [In Persian];1995.  Back to cited text no. 7
    
8.WHO (World Health Organization) Regional Office for Europe, Eho-Europe (2005). Health facilities seismic vulnerability evaluation. Available in: http:// target="_blank" href="www">www.euro.who.int/__data/assets/pdf_file/0007/141784/e88525.pdf.  Back to cited text no. 8
    
9.WHO-Euro. Seismic vulnerability assessment of a key health facility in the former Yugoslav Republic of Macedonia, Copenhagen, Denmark: World Health Organization Regional Office for Europe; 2007. Available from: http:// target="_blank" href="www">www.euro.who.int/en/countries/the-former-yugoslav-republic-of-macedonia/publications3/seismic-vulnerability-assessment-of-a-key-health-facility-in-the-former-yugoslav-republic-of-macedonia.  Back to cited text no. 9
    
10.Seyyedin SH, Toufighi Sh, Malmin Z, Hosseini Shokooh SM. Organizational vulnerability and management of clinical departments against crisis. Iran J Crit Care Nurs 2009;2:99-103 [In Persian].  Back to cited text no. 10
    
11.Shojaei P, Maleki MR, Bagherzadeh R. Studying preparedness in teaching hospitals affiliated to Iran University of Medical Sciences, 2006, Disaster Prevention and Management 2009; 18:4, p. 379-87.  Back to cited text no. 11
    
12.Malekshahi F, Mardani M. Capabilities and limitations of crisis management in social security and Shohada hospitals of Khorramabad in 1385. Crit Care Nurs 2008;1:29-34 [In Persian].  Back to cited text no. 12
    
13.Schultz CH, Koenig KL, Lewis RJ. Implications of hospital evacuation after the Northridge, California earthquake. N Engl J Med 2003;348:1349-55.  Back to cited text no. 13
    
14.Amini Ghazvini S. Methods of reducing risk in health care centers against earthquakes, (Case study: Atieh hospital), MS. dissertation, Shahid Beheshti University, Tehran, Iran [In Persian]; 2010.  Back to cited text no. 14
    



 
 
    Tables

  [Table 1], [Table 2]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

 
  In this article
Abstract
Introduction
Materials and Me...
Results
Conclusion
Acknowledgment
References
Article Tables

 Article Access Statistics
    Viewed2026    
    Printed30    
    Emailed0    
    PDF Downloaded298    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]